CN110071497A - A kind of photovoltaic DC electricity generation system and its control method with energy storage device - Google Patents

Abstract

The invention discloses a kind of photovoltaic DC electricity generation system and its control method with energy storage device.Photovoltaic DC electricity generation system with energy storage device, including 3 photovoltaic arrays, 3 BOOST converters, 2 energy storage devices, 2 two-way DC/DC converters, an ohmic load, a constant power load.The control method that the present invention is proposed for the system is provided with two kinds of operating modes to BOOST converter, that is MPPT control model and constant voltage output mode, 3 kinds of operating modes are provided with to two-way DC/DC converter, respectively BUCK mode, BOOST mode, excision model, controller reasonably switches the operating mode of BOOST converter and two-way DC/DC converter according to the working condition of system, realize the organic integration of photovoltaic array and energy storage device, maximal efficiency utilizes the received solar energy of photovoltaic array while guaranteeing that DC bus is stablized, in light intensity decreasing, controller can make quickly adjustment to guarantee the stabilization of DC bus-bar voltage to load sudden change etc. in special circumstances.

Description

A kind of photovoltaic DC electricity generation system and its control method with energy storage device

Technical field

The invention belongs to the direct-current grid control fields of electric system, are related to a kind of pair of photovoltaic energy storage system and carry out automatically The control algolithm of control is specifically designed into a kind of based on MPPT control, voltage close loop control, current follow-up control, current compensation The control algolithm of control and a kind of photovoltaic energy storage system controlled with the control algolithm.

Background technique

The solar power system not connecting with power grid is referred to as off-network type photovoltaic generating system.This photovoltaic generating system Energy be derived only from solar battery array.When night or illumination deficiency, solar battery array cannot Enough energy are provided for load.So the reliability and stability in order to guarantee off-network type photovoltaic generating system, system are necessary Energy storage device is equipped with to store and adjust electric energy.In the case that illumination is sufficient or light load, energy storage device is in charging Mode gets up the endless energy storage of load consumption；In the case that illumination is insufficient or heavier loads, energy storage device is in Discharge mode provides energy together with solar battery array for load.

The key for guaranteeing the photovoltaic system stable operation of off-network type is to maintain the stabilization of DC bus-bar voltage.At this stage for dimension Holding the control strategy that DC bus-bar voltage fluctuates in stability range mainly has master-slave control method and reciprocity control method.Principal and subordinate Control principle is that the direct equipment for participating in DC bus-bar voltage regulation is set as main control unit, remaining is from control unit；It is right Etc. control modes keep the effect status of each part identical, need to only be carried out by feedback from main regulation, avoid main control unit and Communication contact is interconnected, but the reciprocity method of operation under separate state reduces the robustness of system, makes whole anti-interference ability Weaken.Authorization Notice No. is the Chinese patent of CN201810737614.6, proposes a kind of direct-current grid based on multi-zone supervision The whole control strategy of direct-current micro-grid is decomposed into equipment management layer and bus control layer structure by control method and system.Equipment The each component part of micro-capacitance sensor is regulated and controled according to the characteristic and working method of itself in management level, in bus control layer, setting Operating mode controller according to the division for carrying out operating mode the case where the fluctuation range and battery dump energy of busbar voltage, System is switched under different working condition.

The power that the generating equipment that DC bus-bar voltage maintains stable premise to be in direct-current grid issues needs full The power demand of sufficient electrical equipment.When the power that generating equipment issues is less than the power demand of electrical equipment, busbar voltage meeting Decline, therefore specific power demand is small for the power that electrical equipment obtains, to reach DC bus output power and input power One equilibrium state；When the power that generating equipment issues is greater than the power demand of electrical equipment, busbar voltage can rise, simultaneously Therefore specific power demand is big for the power that electrical equipment obtains.Photovoltaic battery array is used as generating equipment, load always in systems Always it is used as electrical equipment.When photovoltaic apparatus issues power needed for power is greater than load, energy storage device is inhaled as electrical equipment Energy is received, when photovoltaic apparatus issues power needed for power is less than load, energy storage device releases energy as generating equipment.In light When condition variation, load variation, it is straight to guarantee that the operating mode of the equipment in direct-current grid generally requires switching Flow the stabilization of busbar voltage.

Summary of the invention

In order to solve intensity of illumination variation, when load sudden change DC bus-bar voltage stable problem, the present invention sets A kind of photovoltaic DC electricity generation system with energy storage device has been counted, and has proposed a kind of control algolithm for the system.By this control Algorithm processed is applied in photovoltaic DC electricity generation system, needs to reach following control target: 1. setting nominally, photovoltaic Cell array output voltage is connected after the boosting of BOOST circuit with DC bus, guarantees that DC bus-bar voltage and setting refer to Value is consistent, and energy storage device is connected by two-way DC/DC converter with DC bus, and energy storage device is in constant-current charge state, electricity Resistance load is connected in parallel on DC bus；2. on the basis of normal conditions, the remitted its fury for the light that photovoltaic battery array receives, Cause it to be not enough to is energy storage device charging and load supplying simultaneously, and control system needs are cut automatically according to the status information of system Except energy storage device, it is ensured that the power supply of ohmic load and the stabilization of DC bus-bar voltage；3. working as light intensity on the basis of normal conditions Too weak to cause system that after cutting off energy storage device still DC bus-bar voltage control when setting reference value, system is automatic Energy storage device is accessed, ensures the stabilization of DC bus-bar voltage to DC bus injecting power by energy storage device；4. in standard On the basis of situation, a constant power load accesses DC bus suddenly, and photovoltaic array is caused to be not enough to simultaneously as energy storage device Charging and load supplying, control system need to cut off energy storage device automatically according to the status information of system, it is ensured that ohmic load, perseverance The power supply of power termination and the stabilization of DC bus-bar voltage；5. on the basis of normal conditions, needed for the constant power load of access Power causes greatly very much system that DC bus-bar voltage can not still be made to control the system when setting reference value after cutting off energy storage device Automatically energy storage device is accessed, ensures the stabilization of DC bus-bar voltage to DC bus injecting power by energy storage device.

The invention is realized by the following technical scheme: the photovoltaic DC electricity generation system with energy storage device, including 3 photovoltaic battle arrays Column, 3 BOOST converters, 2 energy storage devices, 2 two-way DC/DC converters, an ohmic load, a constant power load, 3 photovoltaic arrays are connected in series by 54 solar batteries, are respectively designated as the first photovoltaic array, the second photovoltaic array, Three photovoltaic arrays, 3 photovoltaic arrays are by the way that, again to DC bus injecting power, 3 BOOST become after BOOST converter boosting Parallel operation is respectively designated as #1 converter, #2 converter, #3 converter, and is classified as BOOST converter group, and BOOST converter has two Kind control model, is constant voltage output control model and MPPT control model respectively；2 energy storage devices are respectively designated as the 4th energy storage Equipment and the 5th energy storage device, energy storage device have 3 working conditions, are constant-current charge state, excision stand-by state, electric discharge respectively State, the excessively two-way DC/DC converter of energy storage device are connected with DC bus, and 2 two-way DC/DC converters are respectively designated as #4 Converter, #5 converter, and it is classified as two-way DC/DC converter group, there are three types of operating modes for two-way DC/DC converter, respectively BOOST operating mode, BUCK operating mode, excision model, when two-way DC/DC converter is in BOOST operating mode, energy storage Equipment is in discharge condition；When two-way DC/DC converter is in BUCK operating mode, energy storage device is in constant-current charge shape State, when two-way DC/DC converter is in excision model, energy storage device is in excision stand-by state.

Further, the control algolithm of the direct current system can be divided into two layers, and wherein the purpose of bottom is control and photovoltaic Two-way DC/DC converter group cell array connected BOOST converter group and be connected with energy storage device, the purpose of top layer are associations BOOST converter group and two-way DC/DC converter group are adjusted, makes DC bus-bar voltage in feelings such as intensity of illumination mutation, load sudden changes The stabilization of DC bus-bar voltage is able to achieve under condition.The control period ts of the control algolithm of the system is 0.00005s, therefore one Secondary complete control, which calculates, to be needed to complete in 0.00005s, and 11 duty ratios can be obtained by completing a control algolithm, respectively D₁、D₂、D₃、D_4A、D_4B、D_4C、D_4D、D_5A、D_5B、D_5C、D_5D, then 11 PWM modules go out therewith according to this 11 duty ratio modulations Corresponding pwm signal, respectively PWM₁、PWM₂、PWM₃、PWM_4A、PWM_4B、PWM_4C、PWM_4D、PWM_5A、PWM_5B、PWM_5C、PWM_5D, Wherein PWM₁Signal is for controlling VT in #1 converter₁Pipe turns on and off, PWM₂Signal is for controlling VT in #2 converter₂ Pipe turns on and off, PWM₃Signal is for controlling VT in #3 converter₃Pipe turns on and off, PWM_4A、PWM_4B、PWM_4C、 PWM_4DSignal is for controlling VT in #4 converter_4A、VT_4B、VT_4C、VT_4DPipe turns on and off, PWM_5A、PWM_5B、PWM_5C、 PWM_5DSignal is for controlling VT in #5 converter_5A、VT_5B、VT_5C、VT_5DPipe turns on and off.

The bottom control of the direct current system includes two large divisions, the control of BOOST converter group and two-way DC/DC converter Control, BOOST converter group is there are two types of control model, and there are three types of control models for two-way DC/DC converter group, and mode is arranged₁ For the operating mode control bit of BOOST converter group, work as mode₁When being 1,3 BOOST converters are all made of MPPT control, when mode₁When being 0,3 BOOST converters are controlled using constant voltage output, and mode is arranged₂For the Working mould of two-way DC/DC converter group Formula control bit, works as mode₂When being 1, two-way DC/DC converter group is in BUCK operating mode, and energy storage device is in constant-current charge State；Work as mode₂When being 2, two-way DC/DC converter group is in BOOST operating mode, and energy storage device is in discharge condition；When mode₂When being 0, two-way DC/DC converter group is in excision state, and energy storage device is in excision stand-by state.

Work as mode₁When being 1, BOOST converter group is in MPPT control model, and the control calculating under the mode can be divided into Following steps:

S1, the output voltage V for reading the first photovoltaic array of current control period₁, output electric current I₁, it is separately stored in Array A₁A₁[1], array B₁B₁[1] in, by the output voltage of a upper control the first photovoltaic array of period, output electric current storage There are array A₁A₁[0], array B₁B₁[0] in, array A₁、B₁Have and only there are two elements；

S2, the difference DELTA for calculating the output voltage of the first photovoltaic array between current control period and a upper control period V₁, export the difference DELTA I of electric current₁；

S3, as Δ V₁With Δ I₁When being 0, the duty ratio D of #1 converter₁It is consistent with a upper control period；As Δ V₁For 0 and Δ I₁When greater than 0, the duty ratio D of #1 converter₁The duty ratio that the period is controlled than upper one increases Δ d, and Δ d is that duty ratio is micro- Increment, the present invention set it to 0.0001；As Δ V₁The Δ I for 0₁When less than 0, the duty ratio D of #1 converter₁Than upper one The duty ratio for controlling the period reduces Δ d；As Δ I₁/ΔV₁=I₁/V₁When, the duty ratio D of #1 converter₁With a upper control period Unanimously；As Δ I₁/ΔV₁>I₁/V₁When, the duty ratio D of #1 converter₁The duty ratio that the period is controlled than upper one reduces Δ d；Work as Δ I₁/ΔV₁<I₁/V₁When, the duty ratio D of #1 converter₁The duty ratio that the period is controlled than upper one increases Δ d；

S4, judge se=0 and V_bus>V_refWhether two conditions are set up simultaneously, and wherein se is the control of BOOST converter group Enable bit, when se is 0, BOOST converter group can be in two kinds of control moulds of MPPT control model and constant voltage output control model Freely switch between formula, when se is 1, BOOST converter group is locked under MPPT control model, V_busFor bus voltage value, V_refFor busbar voltage reference value, after two conditions meet simultaneously, for m from adding, m is counting variable.Then judge whether m is greater than 100, when m is greater than 100, by mode₁It is assigned a value of 0, the operating mode of converter group is made to be switched to constant voltage output control model, and M is reset；

S5, the output voltage V for reading the second photovoltaic array of current control period₂, output electric current I₂, it is separately stored in Array A₂A₂[1], array B₂B₂[1] in, by the output voltage of a upper control the second photovoltaic array of period, output electric current storage There are array A₂A₂[0], array B₂B₂[0] in.Array A₂、B₂Have and only there are two elements；

S6, the difference DELTA for calculating the output voltage of the second photovoltaic array between current control period and a upper control period V₂, export the difference DELTA I of electric current₂；

S7, as Δ V₂With Δ I₂When being 0, the duty ratio D of #2 converter₂It is consistent with a upper control period；As Δ V₂For 0 and Δ I₂When greater than 0, the duty ratio D of #2 converter₂The duty ratio that the period is controlled than upper one increases Δ d；As Δ V₂The Δ for 0 I₂When less than 0, the duty ratio D of #2 converter₂The duty ratio that the period is controlled than upper one reduces Δ d；As Δ I₂/ΔV₂=I₂/V₂ When, the duty ratio D of #2 converter₂It is consistent with a upper control period；As Δ I₂/ΔV₂>I₂/V₂When, the duty ratio of #2 converter D₂The duty ratio that the period is controlled than upper one reduces Δ d；As Δ I₂/ΔV₂<I₂/V₂When, the duty ratio D of #1 converter₂Than upper one The duty ratio in a control period increases Δ d；

S8, the output voltage V for reading current control period third photovoltaic array₃, output electric current I₃, it is separately stored in Array A₃A₃[1], array B₃B₃[1] in, by the output voltage of upper control period third photovoltaic array, output electric current storage There are array A₃A₃[0], array B₃B₃[0] in.Array A₃、B₃Have and only there are two elements；

S9, the difference DELTA for calculating the output voltage of third photovoltaic array between current control period and a upper control period V₃, export the difference DELTA I of electric current₃；

S10, as Δ V₃With Δ I₃When being 0, the duty ratio D of #3 converter₃It is consistent with a upper control period；As Δ V₃ The Δ I for 0₃When greater than 0, the duty ratio D of #3 converter₃The duty ratio that the period is controlled than upper one increases Δ d；As Δ V₃For 0 ΔI₃When less than 0, the duty ratio D of #3 converter₃The duty ratio that the period is controlled than upper one reduces Δ d；As Δ I₃/ΔV₃=I₃/ V₃When, the duty ratio D of #3 converter₃It is consistent with a upper control period；As Δ I₃/ΔV₃>I₃/V₃When, the duty of #3 converter Compare D₃The duty ratio that the period is controlled than upper one reduces Δ d；As Δ I₃/ΔV₃<I₃/V₃When, the duty ratio D of #3 converter₃Than upper The duty ratio in one control period increases Δ d.

Work as mode₁When being 0, BOOST converter group is in constant voltage output control model, and control under the mode calculates can be with It is divided into following steps:

S11, busbar voltage reference value V is calculated_refWith bus voltage value V_busDifference, and difference is assigned in₁[1]。in₁ The in of array₁That [1] store is the control margin of error of current control period, in₁[0] storage is upper one control for controlling the period The margin of error, out₁The out of array₁That [1] store is the PI control result of current control period, out₁[0] storage is a upper control The PI control result in period processed；

S12, PI control operation is carried out, by the control margin of error in of current control period₁[1], the control in a upper control period Margin of error in processed₁[0], the PI control result out in a upper control period₁[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₁[1]；

S13, to PI control result out₁[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To the duty ratio D of #1 converter₁；

S14, judge V_bus<V_refWhether -3 and se is true equal to 0 the two conditions, as long as any one in two conditions Part is set up, just by mode₁1 is set, converter group is switched to MPPT control model；

S15, the output electric current I for calculating #1 converter₁The output electric current I of _ out and #2 converter₂The difference of _ out, and will Difference is assigned in₂[1], in₂The in of array₂That [1] store is the control margin of error of current control period, in₂[0] storage is The control margin of error in a upper control period, out₂The out of array₂[1] what is stored is the PI control result of current control period, out₂[0] storage is the upper one PI control result for controlling the period；

S16, PI control operation is carried out, by the control margin of error in of current control period₂[1], the control in a upper control period Margin of error in processed₂[0], the PI control result out in a upper control period₂[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₂[1]；

S17, to PI control result out₂[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To the duty ratio D of #2 converter₂；

S18, the output electric current I for calculating #3 converter₁The output electric current I of _ out and #3 converter₃The difference of _ out, and will Difference is assigned in₃[1], in₃The in of array₃That [1] store is the control margin of error of current control period, in₃[0] storage is The control margin of error in a upper control period, out₃The out of array₃[1] what is stored is the PI control result of current control period, out₃[0] storage is the upper one PI control result for controlling the period；

S19, PI control operation is carried out, by the control margin of error in of current control period₃[1], the control in a upper control period Margin of error in processed₃[0], the PI control result out in a upper control period₃[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₃[1]；

S20, to PI control result out₃[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To the duty ratio D of #3 converter₃。

Work as mode₂When being 1, #4 converter and #5 converter are in BUCK operating mode, and the control calculating under the mode can To be divided into following steps:

S21, due to charging when, the direction of inductive current and the positive direction of setting are on the contrary, so need inductance L_4a、L_4b In the electric current I that flows through_4a、I_4bIt negates；

S22, I is calculated_{R_in}/ 2 and I_4aDifference, and difference is assigned in₄[1], I is calculated_{R_in}/ 2 and I_4bDifference, and will Difference is assigned in₅[1], I_{R_in}For the charging current reference value of energy storage device, in₄The in of array₄[1] storage is currently to control The control margin of error in period, in₄[0] that storage is the upper one control margin of error for controlling the period, out₄The out of array₄[1] it stores Be current control period PI control result, out₄[0] that storage is the upper one PI control result for controlling the period, in₅Array in₅That [1] store is the control margin of error of current control period, in₅[0] storage is the upper one control margin of error for controlling the period, out₅The out of array₅That [1] store is the PI control result of current control period, out₅[0] storage was a upper control period PI control result；

S23, PI control operation is carried out, by the control margin of error in of current control period₄[1], the control in a upper control period Margin of error in processed₄[0], the PI control result out in a upper control period₄[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₄[1], by the control margin of error in of current control period₅[1], a upper control period Control margin of error in₅[0], the PI control result out in a upper control period₅[0] the discrete computing expression formula of PI control is substituted into, Obtain the PI control result out of current control period₅[1]；

S24, to PI control result out₄[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To VT in #4 converter_4AThe duty ratio D of pipe_4A, to PI control result out₅[1] clipping is carried out, is limited between zero and one, and Result after clipping is assigned to VT in #4 converter_4BThe duty ratio D of pipe_4B, VT in #4 converter_4CThe duty ratio D of pipe_4C, #4 transformation VT in device_4DThe duty ratio D of pipe_4DIt is assigned a value of 0；

S25, due to charging when, the direction of inductive current and the positive direction of setting are on the contrary, so need inductance L_5a、L_5b In the electric current I that flows through_5a、I_5bIt negates；

S26, I is calculated_{R_in}/ 2 and I_5aDifference, and difference is assigned in₉[1], I is calculated_{R_in}/ 2 and I_5bDifference, and will Difference is assigned in₁₀[1], in₉The in of array₉That [1] store is the control margin of error of current control period, in₉[0] storage is The control margin of error in a upper control period, out₉The out of array₉[1] what is stored is the PI control result of current control period, out₉[0] that storage is the upper one PI control result for controlling the period, in₁₀The in of array₁₀[1] storage is current control period Control the margin of error, in₁₀[0] that storage is the upper one control margin of error for controlling the period, out₁₀The out of array₁₀[1] storage is The PI control result of current control period, out₁₀[0] storage is the upper one PI control result for controlling the period；

S27, PI control operation is carried out, by the control margin of error in of current control period₉[1], the control in a upper control period Margin of error in processed₉[0], the PI control result out in a upper control period₉[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₉[1], by the control margin of error in of current control period₁₀[1], a upper control period Control margin of error in₁₀[0], the PI control result out in a upper control period₁₀[0] the discrete computing expression of PI control is substituted into Formula obtains the PI control result out of current control period₁₀[1]；

S28, to PI control result out₉[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To VT in #5 converter_5AThe duty ratio D of pipe_5A, to PI control result out₁₀[1] clipping is carried out, is limited between zero and one, And the result after clipping is assigned to VT in #5 converter_5BThe duty ratio D of pipe_5B, VT in #5 converter_5CThe duty ratio D of pipe_5C, #5 become VT in parallel operation_5DThe duty ratio D of pipe_5DIt is assigned a value of 0.

Work as mode₂When being 2, #4 converter and #5 converter are in BOOST operating mode, and the control calculating under the mode can To be divided into following steps:

S29, busbar voltage reference value V is calculated_refWith bus voltage value V_busDifference, and difference is assigned in₆[1], in₆ The in of array₆That [1] store is the control margin of error of current control period, in₆[0] storage is upper one control for controlling the period The margin of error, out₆The out of array₆That [1] store is the PI control result of current control period, out₆[0] storage is a upper control The PI control result in period processed；

S30, PI control operation is carried out, by the control margin of error in of current control period₆[1], the control in a upper control period Margin of error in processed₆[0], the PI control result out in a upper control period₆[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₆[1]；

S31, by out₆[1] it is assigned to I_{R_out4}, I_{R_out4}For the output current reference value of energy storage device；

S32, I is calculated_{R_out4}/ 2 and I_4aDifference, and difference is assigned in₇[1], I is calculated_{R_out4}/ 2 and I_4bDifference, and Difference is assigned in₈[1], I_{R_out4}For the output current reference value of energy storage device.In₇The in of array₇[1] storage is currently to control The control margin of error in period processed, in₇[0] that storage is the upper one control margin of error for controlling the period, out₇The out of array₇[1] it stores up That deposit is the PI control result of current control period, out₇[0] that storage is the upper one PI control result for controlling the period, in₈Array In₈That [1] store is the control margin of error of current control period, in₈[0] storage is the upper one control error for controlling the period Amount, out₈The out of array₈That [1] store is the PI control result of current control period, out₈[0] storage was upper control week The PI control result of phase；

S33, PI control operation is carried out, by the control margin of error in of current control period₇[1], the control in a upper control period Margin of error in processed₇[0], the PI control result out in a upper control period₇[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₇[1], by the control margin of error in of current control period₈[1], a upper control period Control margin of error in₈[0], the PI control result out in a upper control period₈[0] the discrete computing expression formula of PI control is substituted into, Obtain the PI control result out of current control period₈[1]；

S34, to PI control result out₇[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To VT in #4 converter_4CThe duty ratio D of pipe_4C, to PI control result out₈[1] clipping is carried out, is limited between zero and one, and Result after clipping is assigned to VT in #4 converter_4DThe duty ratio D of pipe_4D, VT in #4 converter_4AThe duty ratio D of pipe_4A, #4 transformation VT in device_4BThe duty ratio D of pipe_4BIt is assigned a value of 0；

S35, #4 converter output electric current I is calculated_{4_}Out and #5 converter export electric current I_{5_}The difference of out, and by difference It is assigned in₁₁[1], in₁₁The in of array₁₁That [1] store is the control margin of error of current control period, in₁₁[0] storage be on The control margin of error in one control period, out₁₁The out of array₁₁[1] what is stored is the PI control result of current control period, out₁₁[0] storage is the upper one PI control result for controlling the period；

S36, PI control operation is carried out, by the control margin of error in of current control period₁₁[1], the control in a upper control period Margin of error in processed₁₁[0], the PI control result out in a upper control period₁₁[0] the discrete computing expression formula for substituting into PI control, obtains To the PI control result out of current control period₁₁[1]；

S37, by I₄It is superimposed with out₁₁[1] I is obtained_{R_out5}, I_{R_out5}For the output current reference value of the 5th energy storage device；

S38, I is calculated_{R_out5}/ 2 and I_5aDifference, and difference is assigned in₁₂[1], I is calculated_{R_out5}/ 2 and I_5bDifference, And difference is assigned in₁₃[1], I_{R_out5}For the output current reference value of the 5th energy storage device, in₁₂The in of array₁₂[1] it stores It is the control margin of error of current control period, in₁₂[0] that storage is the upper one control margin of error for controlling the period, out₁₂Array out₁₂That [1] store is the PI control result of current control period, out₁₂[0] storage is the upper one PI control for controlling the period As a result, in₁₃The in of array₁₃That [1] store is the control margin of error of current control period, in₁₃[0] storage is a upper control The control margin of error in period, out₁₃The out of array₁₃That [1] store is the PI control result of current control period, out₁₃[0] it stores up What is deposited was the PI control result in a upper control period；

S39, PI control operation is carried out, by the control margin of error in of current control period₁₂[1], the control in a upper control period Margin of error in processed₁₂[0], the PI control result out in a upper control period₁₂[0] the discrete computing expression formula for substituting into PI control, obtains To the PI control result out of current control period₁₂[1], by the control margin of error in of current control period₁₃[1], a upper control The control margin of error in period₁₃[0], the PI control result out in a upper control period₁₃[0] the discrete computing table of PI control is substituted into Up to formula, the PI control result out of current control period is obtained₁₃[1]；

S40, to PI control result out₁₂[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To VT in #5 converter_5CThe duty ratio D of pipe_5C, to PI control result out₁₃[1] clipping is carried out, is limited between zero and one, And the result after clipping is assigned to VT in #5 converter_5DThe duty ratio D of pipe_5D, VT in #5 converter_5AThe duty ratio D of pipe_5A, #5 become VT in parallel operation_5BThe duty ratio D of pipe_5BIt is assigned a value of 0.

Further, BOOST converter group is in MPPT operating mode when system starts, and two-way DC/DC converter is in BUCK operating mode, energy storage device charging.It charges needed for required power and load if the peak power output of photovoltaic array is greater than The sum of power, DC bus-bar voltage will be higher than busbar voltage reference value after starting a period of time, at this moment BOOST converter group Controller will automatically switch to constant voltage output control, make photovoltaic array output with charge needed for power and load needed for power it With equal power, to guarantee that DC bus-bar voltage is consistent with busbar voltage reference value.If the maximum work output of photovoltaic array Rate is less than charge the sum of required power and power needed for load, but is greater than the required power of load, then needs to cut off two-way DC/DC change Parallel operation group；If the peak power output of photovoltaic array, which is less than, loads required power, two-way DC/DC converter is needed to be in BOOST operating mode, energy storage device electric discharge, while photovoltaic array needs to be constantly in MPPT operating mode.

Size relation between power needed for power, charging as needed for can not directly compare peak power output and load, So control model can only be carried out to BOOST converter group and two-way DC/DC converter group by the judgement of other conditions Switching, to guarantee that DC bus-bar voltage is consistent with busbar voltage reference value.

Further, BOOST converter group and two-way DC/DC converter group mode coordinated control the following steps are included:

S41, judge mode₁=1, mode₂=1, V_bus<V_refWhether three conditions are set up simultaneously, if set up simultaneously, By the variable x for being used to count from adding, S43 is otherwise skipped to；

Whether the x of S42, judgement from after adding is greater than 2000, if it is greater than 2000, then by mode₂It is assigned a value of 0, disconnects switch S4, S5 make energy storage device be in excision stand-by state, and x are reset；

S43, judge mode₁=1, mode₂=0, V_bus<V_refWhether three conditions are set up simultaneously, if set up simultaneously, By the variable y for being used to count from adding, S45 is otherwise skipped to；

Whether the y of S44, judgement from after adding is greater than 2000, if it is greater than 2000, then by mode₂2 are assigned a value of, and is closed and opens S4, S5 are closed, so that energy storage device is in discharge condition, and y is reset；

S45, end mode are coordinated；

Further, the present invention shares 13 PI control operations, and the fortune of these PI control operation in the period is controlled at one Calculation process is respectively as follows:

Wherein p₁For the first proportionality coefficient, i₁For first integral coefficient, ts is the control period.

Wherein p₂For the second proportionality coefficient, i₂For second integral coefficient.

Wherein p₃For third proportionality coefficient, i₃For third integral coefficient.

Wherein p₄For the 4th proportionality coefficient, i₄For the 4th integral coefficient.

Wherein p₅For the 5th proportionality coefficient, i₅For the 5th integral coefficient.

Wherein p₆For the 6th proportionality coefficient, i₆For the 6th integral coefficient.

Wherein p₇For the 7th proportionality coefficient, i₇For the 7th integral coefficient.

Wherein p₈For the 8th proportionality coefficient, i₈For the 8th integral coefficient.

Wherein p₉For the 9th proportionality coefficient, i₉For the 9th integral coefficient.

Wherein p₁₀For the tenth proportionality coefficient, i₁₀For the tenth integral coefficient.

Wherein p₁₁For the 11st proportionality coefficient, i₁₁For the 11st integral coefficient.

Wherein p₁₂For the 12nd proportionality coefficient, i₁₂For the 12nd integral coefficient.

Wherein p₁₃For the 13rd proportionality coefficient, i₁₃For the 13rd integral coefficient.

The beneficial effects of the present invention are: the present invention is directed to by three photovoltaic arrays, two energy storage devices, 3 BOOST transformation The off-network type photovoltaic system that device, 2 two-way DC/DC converters, DC load form proposes control method.The control method is given BOOST converter group is provided with two kinds of operating modes, i.e. MPPT control model and constant voltage output mode, and controller can basis The operating mode of the size of DC bus-bar voltage and two-way DC/DC converter group carries out operating mode to BOOST converter and cuts It changes, fixes photovoltaic array flexibly according to the power demand output power of system, compared to traditional by photovoltaic array Method on MPPT output mode is more flexible, is more able to satisfy the self-sustaining feature of off-network type photovoltaic system energy-autarchic.The control Method processed is provided with 3 kinds of operating modes, respectively BUCK mode, BOOST mode, excision model to two-way DC/DC converter group, Controller reasonably switches the operating mode of two-way DC/DC converter according to the working condition of system.Work as photovoltaic array Two-way DC/DC converter is in BUCK work when the sum of power needed for peak power output is greater than energy storage device charge power and loads Operation mode makes energy storage device constant-current charge, utilizes solar energy to greatest extent；When photovoltaic array peak power output is less than energy storage Equipment charge power is in greater than DC/DC converter two-way when loading required power with the sum of required power is loaded and cuts off mould Formula enables the load to obtain enough energy；Two-way DC/DC when the power needed for photovoltaic array peak power output is less than and loads Converter, which is in BOOST operating mode, makes energy storage device discharge, and maintains the stabilization of DC bus-bar voltage.Generally speaking, the control Photovoltaic array and energy storage device can be integrated organically and provide a reliable energy source for load by method, guaranteed The utilization photovoltaic array received solar energy of maximal efficiency while DC bus stabilization, in spies such as light intensity decreasing, load sudden changes Controller can make quick adjustment in different situation.

Detailed description of the invention

Fig. 1 is the main circuit diagram of the embodiment of the present invention.

Fig. 2 is the control flow chart of the #1 converter of the embodiment of the present invention.

Fig. 3 is the control flow chart of the #2 converter of the embodiment of the present invention.

Fig. 4 is the control flow chart of the #3 converter of the embodiment of the present invention.

Fig. 5 is the control flow chart of the #4 converter of the embodiment of the present invention.

Fig. 6 is the control flow chart of the #5 converter of the embodiment of the present invention.

Mode of the Fig. 7 between BOOST converter of embodiment of the present invention group and two-way DC/DC converter group coordinates process Figure.

Fig. 8 is DC bus-bar voltage waveform, pattern switching wave of the embodiment of the present invention when loading variation in PLECS emulation Shape.

Fig. 9 is BOOST converter output current wave of the embodiment of the present invention when loading variation in PLECS emulation.

Figure 10 is that two-way DC/DC converter of the embodiment of the present invention when loading variation exports current wave in PLECS emulation Shape.

Figure 11 is energy storage device output current wave of the embodiment of the present invention when loading variation in PLECS emulation.

Figure 12 be PLECS emulation in the embodiment of the present invention intensity of illumination change when DC bus-bar voltage waveform, mode Switching waveform.

Figure 13 is that BOOST converter of the embodiment of the present invention when intensity of illumination changes exports current wave in PLECS emulation Shape.

Figure 14 is that two-way DC/DC converter of the embodiment of the present invention when intensity of illumination changes exports electricity in PLECS emulation Flow waveform.

Figure 15 is energy storage device output current wave of the embodiment of the present invention when intensity of illumination changes in PLECS emulation.

Specific embodiment

Technical solution of the present invention is further illustrated with reference to the accompanying drawing.

As shown in Figure 1, the photovoltaic DC electricity generation system with energy storage device, including 3 photovoltaic arrays, 3 BOOST transformation Device, 2 energy storage devices, 2 two-way DC/DC converters, an ohmic load, a constant power load, 3 photovoltaic arrays by 54 solar batteries are connected in series, and are respectively designated as the first photovoltaic array, the second photovoltaic array, third photovoltaic array, 3 light Photovoltaic array is by the way that, again to DC bus injecting power, 3 BOOST converters are respectively designated as #1 after BOOST converter boosting Converter, #2 converter, #3 converter, and it is classified as BOOST converter group, there are two types of control models for BOOST converter, are respectively Constant voltage output control model and MPPT control model；2 energy storage devices are respectively designated as the 4th energy storage device and the 5th energy storage is set Standby, energy storage device has 3 working conditions, is constant-current charge state, excision stand-by state, discharge condition respectively, and energy storage device is equal It crosses two-way DC/DC converter to be connected with DC bus, 2 two-way DC/DC converters are respectively designated as #4 converter, #5 transformation Device, and be classified as two-way DC/DC converter group, two-way DC/DC converter there are three types of operating mode, respectively BOOST operating mode, BUCK operating mode, excision model, when two-way DC/DC converter is in BOOST operating mode, energy storage device is in electric discharge shape State；When two-way DC/DC converter is in BUCK operating mode, energy storage device is in constant-current charge state, when two-way DC/DC becomes When parallel operation is in excision model, energy storage device is in excision stand-by state.

Further, the control algolithm of the direct current system can be divided into two layers, wherein the purpose of bottom control be control with Two-way DC/DC converter group photovoltaic battery array connected BOOST converter group and be connected with energy storage device, top layer control Purpose is to coordinate BOOST converter group and two-way DC/DC converter group, makes DC bus-bar voltage in intensity of illumination mutation, load The stabilization of DC bus-bar voltage is able to achieve when mutation.The control period ts of the control algolithm of the system is 0.00005s, therefore primary complete control calculates and needs to complete in 0.00005s, 11 can be obtained by completing a control algolithm A duty ratio, respectively D₁、D₂、D₃、D_4A、D_4B、D_4C、D_4D、D_5A、D_5B、D_5C、D_5D, then 11 PWM modules are accounted for according to this 11 Sky is than modulating corresponding pwm signal, respectively PWM₁、PWM₂、PWM₃、PWM_4A、PWM_4B、PWM_4C、PWM_4D、PWM_5A、 PWM_5B、PWM_5C、PWM_5D, wherein PWM₁Signal is for controlling VT in #1 converter₁Pipe turns on and off, PWM₂Signal is for controlling VT in #2 converter processed₂Pipe turns on and off, PWM₃Signal is for controlling VT in #3 converter₃Pipe turns on and off, PWM_4A、PWM_4B、PWM_4C、PWM_4DSignal is for controlling VT in #4 converter_4A、VT_4B、VT_4C、VT_4DPipe turns on and off, PWM_5A、PWM_5B、PWM_5C、PWM_5DSignal is for controlling VT in #5 converter_5A、VT_5B、VT_5C、VT_5DPipe turns on and off.

The bottom control of the direct current system includes two large divisions, the control of BOOST converter group and two-way DC/DC converter Control, BOOST converter group is there are two types of control model, and there are three types of control models for two-way DC/DC converter, and mode is arranged₁For The operating mode control bit of BOOST converter group, works as mode₁When being 1,3 BOOST converters are all made of MPPT control, when mode₁When being 0,3 BOOST converters are all made of constant voltage output control, and mode is arranged₂For the work of two-way DC/DC converter group Scheme control position, works as mode₂When being 1, two-way DC/DC converter group is in BUCK operating mode, and energy storage device is filled in constant current Electricity condition；Work as mode₂When being 2, two-way DC/DC converter group is in BOOST operating mode, and energy storage device is in discharge condition； Work as mode₂When being 0, two-way DC/DC converter group is in excision state, the duty of all switching tubes of two-way DC/DC converter Than being 0, energy storage device is in excision stand-by state.

As shown in Figure 2, Figure 3, Figure 4, work as mode₁When being 1, BOOST converter group is in MPPT control model, under the mode Control calculating can be divided into following steps:

S1, the output voltage V for reading the first photovoltaic array of current control period₁, output electric current I₁, it is separately stored in Array A₁A₁[1], array B₁B₁[1] in, by the output voltage of a upper control the first photovoltaic array of period, output electric current storage There are array A₁A₁[0], array B₁B₁[0] in, array A₁、B₁Have and only there are two elements；

S2, the difference DELTA for calculating the output voltage of the first photovoltaic array between current control period and a upper control period V₁, export the difference DELTA I of electric current₁；

S3, as Δ V₁With Δ I₁When being 0, the duty ratio D of #1 converter₁It is consistent with a upper control period；As Δ V₁For 0 and Δ I₁When greater than 0, the duty ratio D of #1 converter₁The duty ratio that the period is controlled than upper one increases Δ d, and Δ d is that duty ratio is micro- Increment, the present invention set it to 0.0001；As Δ V₁The Δ I for 0₁When less than 0, the duty ratio D of #1 converter₁Than upper one The duty ratio for controlling the period reduces Δ d；As Δ I₁/ΔV₁=I₁/V₁When, the duty ratio D of #1 converter₁With a upper control period Unanimously；As Δ I₁/ΔV₁>I₁/V₁When, the duty ratio D of #1 converter₁The duty ratio that the period is controlled than upper one reduces Δ d；Work as Δ I₁/ΔV₁<I₁/V₁When, the duty ratio D of #1 converter₁The duty ratio that the period is controlled than upper one increases Δ d；

S4, judge se=0 and V_bus>V_refWhether two conditions are set up simultaneously, and wherein se is the control of BOOST converter group Enable bit, when se is 0, BOOST converter group can be in two kinds of control moulds of MPPT control model and constant voltage output control model Freely switch between formula, when se is 1, BOOST converter group is locked under MPPT control model, V_busFor bus voltage value, V_refFor busbar voltage reference value, after two conditions meet simultaneously, for m from adding, m is counting variable.Then judge whether m is greater than 100, when m is greater than 100, by mode₁It is assigned a value of 0, the operating mode of converter group is made to be switched to constant voltage output control model, and M is reset；

S5, the output voltage V for reading the second photovoltaic array of current control period₂, output electric current I₂, it is separately stored in Array A₂A₂[1], array B₂B₂[1] in, by the output voltage of a upper control the second photovoltaic array of period, output electric current storage There are array A₂A₂[0], array B₂B₂[0] in.Array A₂、B₂Have and only there are two elements；

S6, the difference DELTA for calculating the output voltage of the second photovoltaic array between current control period and a upper control period V₂, export the difference DELTA I of electric current₂；

S7, as Δ V₂With Δ I₂When being 0, the duty ratio D of #2 converter₂It is consistent with a upper control period；As Δ V₂For 0 and Δ I₂When greater than 0, the duty ratio D of #2 converter₂The duty ratio that the period is controlled than upper one increases Δ d；As Δ V₂The Δ for 0 I₂When less than 0, the duty ratio D of #2 converter₂The duty ratio that the period is controlled than upper one reduces Δ d；As Δ I₂/ΔV₂=I₂/V₂ When, the duty ratio D of #2 converter₂It is consistent with a upper control period；As Δ I₂/ΔV₂>I₂/V₂When, the duty ratio of #2 converter D₂The duty ratio that the period is controlled than upper one reduces Δ d；As Δ I₂/ΔV₂<I₂/V₂When, the duty ratio D of #1 converter₂Than upper one The duty ratio in a control period increases Δ d；

S8, the output voltage V for reading current control period third photovoltaic array₃, output electric current I₃, it is separately stored in Array A₃A₃[1], array B₃B₃[1] in, by the output voltage of upper control period third photovoltaic array, output electric current storage There are array A₃A₃[0], array B₃B₃[0] in.Array A₃、B₃Have and only there are two elements；

S9, the difference DELTA for calculating the output voltage of third photovoltaic array between current control period and a upper control period V₃, export the difference DELTA I of electric current₃；

S10, as Δ V₃With Δ I₃When being 0, the duty ratio D of #3 converter₃It is consistent with a upper control period；As Δ V₃ The Δ I for 0₃When greater than 0, the duty ratio D of #3 converter₃The duty ratio that the period is controlled than upper one increases Δ d；As Δ V₃For 0 ΔI₃When less than 0, the duty ratio D of #3 converter₃The duty ratio that the period is controlled than upper one reduces Δ d；As Δ I₃/ΔV₃=I₃/ V₃When, the duty ratio D of #3 converter₃It is consistent with a upper control period；As Δ I₃/ΔV₃>I₃/V₃When, the duty of #3 converter Compare D₃The duty ratio that the period is controlled than upper one reduces Δ d；As Δ I₃/ΔV₃<I₃/V₃When, the duty ratio D of #3 converter₃Than upper The duty ratio in one control period increases Δ d.

As shown in Figure 2, Figure 3, Figure 4, work as mode₁When being 0, BOOST converter group is in constant voltage output control model, the mould Control calculating under formula can be divided into following steps:

S11, busbar voltage reference value V is calculated_refWith bus voltage value V_busDifference, and difference is assigned in₁[1]。in₁ The in of array₁That [1] store is the control margin of error of current control period, in₁[0] storage is upper one control for controlling the period The margin of error, out₁The out of array₁That [1] store is the PI control result of current control period, out₁[0] storage is a upper control The PI control result in period processed；

S12, PI control operation is carried out, by the control margin of error in of current control period₁[1], the control in a upper control period Margin of error in processed₁[0], the PI control result out in a upper control period₁[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₁[1]；

S13, to PI control result out₁[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To the duty ratio D of #1 converter₁；

S14, judge V_bus<V_refWhether -3 and se is true equal to 0 the two conditions, as long as any one in two conditions Part is set up, just by mode₁1 is set, converter group is switched to MPPT control model；

S15, the output electric current I for calculating #1 converter₁The output electric current I of _ out and #2 converter₂The difference of _ out, and will Difference is assigned in₂[1], in₂The in of array₂That [1] store is the control margin of error of current control period, in₂[0] storage is The control margin of error in a upper control period, out₂The out of array₂[1] what is stored is the PI control result of current control period, out₂[0] storage is the upper one PI control result for controlling the period；

S16, PI control operation is carried out, by the control margin of error in of current control period₂[1], the control in a upper control period Margin of error in processed₂[0], the PI control result out in a upper control period₂[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₂[1]；

S17, to PI control result out₂[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To the duty ratio D of #2 converter₂；

S18, the output electric current I for calculating #3 converter₁The output electric current I of _ out and #3 converter₃The difference of _ out, and will Difference is assigned in₃[1], in₃The in of array₃That [1] store is the control margin of error of current control period, in₃[0] storage is The control margin of error in a upper control period, out₃The out of array₃[1] what is stored is the PI control result of current control period, out₃[0] storage is the upper one PI control result for controlling the period；

S19, PI control operation is carried out, by the control margin of error in of current control period₃[1], the control in a upper control period Margin of error in processed₃[0], the PI control result out in a upper control period₃[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₃[1]；

S20, to PI control result out₃[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To the duty ratio D of #3 converter₃。

As shown in Figure 5, Figure 6, work as mode₂When being 1, #4 converter and #5 converter are in BUCK operating mode, the mode Under control calculating can be divided into following steps:

S21, due to charging when, the direction of inductive current and the positive direction of setting are on the contrary, so need inductance L_4a、L_4b In the electric current I that flows through_4a、I_4bIt negates；

S22, I is calculated_{R_in}/ 2 and I_4aDifference, and difference is assigned in₄[1], I is calculated_{R_in}/ 2 and I_4bDifference, and will Difference is assigned in₅[1], I_{R_in}For the charging current reference value of energy storage device, in₄The in of array₄[1] storage is currently to control The control margin of error in period, in₄[0] that storage is the upper one control margin of error for controlling the period, out₄The out of array₄[1] it stores Be current control period PI control result, out₄[0] that storage is the upper one PI control result for controlling the period, in₅Array in₅That [1] store is the control margin of error of current control period, in₅[0] storage is the upper one control margin of error for controlling the period, out₅The out of array₅That [1] store is the PI control result of current control period, out₅[0] storage was a upper control period PI control result；

S23, PI control operation is carried out, by the control margin of error in of current control period₄[1], the control in a upper control period Margin of error in processed₄[0], the PI control result out in a upper control period₄[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₄[1], by the control margin of error in of current control period₅[1], a upper control period Control margin of error in₅[0], the PI control result out in a upper control period₅[0] the discrete computing expression formula of PI control is substituted into, Obtain the PI control result out of current control period₅[1]；

S24, to PI control result out₄[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To VT in #4 converter_4AThe duty ratio D of pipe_4A, to PI control result out₅[1] clipping is carried out, is limited between zero and one, and Result after clipping is assigned to VT in #4 converter_4BThe duty ratio D of pipe_4B, VT in #4 converter_4CThe duty ratio D of pipe_4C, #4 transformation VT in device_4DThe duty ratio D of pipe_4DIt is assigned a value of 0；

S25, due to charging when, the direction of inductive current and the positive direction of setting are on the contrary, so need inductance L_5a、L_5b In the electric current I that flows through_5a、I_5bIt negates；

S26, I is calculated_{R_in}/ 2 and I_5aDifference, and difference is assigned in₉[1], I is calculated_{R_in}/ 2 and I_5bDifference, and will Difference is assigned in₁₀[1], in₉The in of array₉That [1] store is the control margin of error of current control period, in₉[0] storage is The control margin of error in a upper control period, out₉The out of array₉[1] what is stored is the PI control result of current control period, out₉[0] that storage is the upper one PI control result for controlling the period, in₁₀The in of array₁₀[1] storage is current control period Control the margin of error, in₁₀[0] that storage is the upper one control margin of error for controlling the period, out₁₀The out of array₁₀[1] storage is The PI control result of current control period, out₁₀[0] storage is the upper one PI control result for controlling the period；

S27, PI control operation is carried out, by the control margin of error in of current control period₉[1], the control in a upper control period Margin of error in processed₉[0], the PI control result out in a upper control period₉[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₉[1], by the control margin of error in of current control period₁₀[1], a upper control period Control margin of error in₁₀[0], the PI control result out in a upper control period₁₀[0] the discrete computing expression of PI control is substituted into Formula obtains the PI control result out of current control period₁₀[1]；

S28, to PI control result out₉[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To VT in #5 converter_5AThe duty ratio D of pipe_5A, to PI control result out₁₀[1] clipping is carried out, is limited between zero and one, And the result after clipping is assigned to VT in #5 converter_5BThe duty ratio D of pipe_5B, VT in #5 converter_5CThe duty ratio D of pipe_5C, #5 become VT in parallel operation_5DThe duty ratio D of pipe_5DIt is assigned a value of 0.

As shown in Figure 5, Figure 6, work as mode₂When being 2, #4 converter and #5 converter are in BOOST operating mode, the mode Under control calculating can be divided into following steps:

S29, busbar voltage reference value V is calculated_refWith bus voltage value V_busDifference, and difference is assigned in₆[1], in₆ The in of array₆That [1] store is the control margin of error of current control period, in₆[0] storage is upper one control for controlling the period The margin of error, out₆The out of array₆That [1] store is the PI control result of current control period, out₆[0] storage is a upper control The PI control result in period processed；

S30, PI control operation is carried out, by the control margin of error in of current control period₆[1], the control in a upper control period Margin of error in processed₆[0], the PI control result out in a upper control period₆[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₆[1]；

S31, by out₆[1] it is assigned to I_{R_out4}, I_{R_out4}For the output current reference value of energy storage device；

S32, I is calculated_{R_out4}/ 2 and I_4aDifference, and difference is assigned in₇[1], I is calculated_{R_out4}/ 2 and I_4bDifference, and Difference is assigned in₈[1], I_{R_out4}For the output current reference value of energy storage device.In₇The in of array₇[1] storage is currently to control The control margin of error in period processed, in₇[0] that storage is the upper one control margin of error for controlling the period, out₇The out of array₇[1] it stores up That deposit is the PI control result of current control period, out₇[0] that storage is the upper one PI control result for controlling the period, in₈Array In₈That [1] store is the control margin of error of current control period, in₈[0] storage is the upper one control error for controlling the period Amount, out₈The out of array₈That [1] store is the PI control result of current control period, out₈[0] storage was upper control week The PI control result of phase；

S33, PI control operation is carried out, by the control margin of error in of current control period₇[1], the control in a upper control period Margin of error in processed₇[0], the PI control result out in a upper control period₇[0] the discrete computing expression formula for substituting into PI control, obtains The PI control result out of current control period₇[1], by the control margin of error in of current control period₈[1], a upper control period Control margin of error in₈[0], the PI control result out in a upper control period₈[0] the discrete computing expression formula of PI control is substituted into, Obtain the PI control result out of current control period₈[1]；

S34, to PI control result out₇[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To VT in #4 converter_4CThe duty ratio D of pipe_4C, to PI control result out₈[1] clipping is carried out, is limited between zero and one, and Result after clipping is assigned to VT in #4 converter_4DThe duty ratio D of pipe_4D, VT in #4 converter_4AThe duty ratio D of pipe_4A, #4 transformation VT in device_4BThe duty ratio D of pipe_4BIt is assigned a value of 0；

S35, #4 converter output electric current I is calculated_{4_}Out and #5 converter export electric current I_{5_}The difference of out, and by difference It is assigned in₁₁[1], in₁₁The in of array₁₁That [1] store is the control margin of error of current control period, in₁₁[0] storage be on The control margin of error in one control period, out₁₁The out of array₁₁[1] what is stored is the PI control result of current control period, out₁₁[0] storage is the upper one PI control result for controlling the period；

S36, PI control operation is carried out, by the control margin of error in of current control period₁₁[1], the control in a upper control period Margin of error in processed₁₁[0], the PI control result out in a upper control period₁₁[0] the discrete computing expression formula for substituting into PI control, obtains To the PI control result out of current control period₁₁[1]；

S37, by I₄It is superimposed with out₁₁[1] I is obtained_{R_out5}, I_{R_out5}For the output current reference value of the 5th energy storage device；

S38, I is calculated_{R_out5}/ 2 and I_5aDifference, and difference is assigned in₁₂[1], I is calculated_{R_out5}/ 2 and I_5bDifference, And difference is assigned in₁₃[1], I_{R_out5}For the output current reference value of the 5th energy storage device, in₁₂The in of array₁₂[1] it stores It is the control margin of error of current control period, in₁₂[0] that storage is the upper one control margin of error for controlling the period, out₁₂Array out₁₂That [1] store is the PI control result of current control period, out₁₂[0] storage is the upper one PI control for controlling the period As a result, in₁₃The in of array₁₃That [1] store is the control margin of error of current control period, in₁₃[0] storage is a upper control The control margin of error in period, out₁₃The out of array₁₃That [1] store is the PI control result of current control period, out₁₃[0] it stores up What is deposited was the PI control result in a upper control period；

S39, PI control operation is carried out, by the control margin of error in of current control period₁₂[1], the control in a upper control period Margin of error in processed₁₂[0], the PI control result out in a upper control period₁₂[0] the discrete computing expression formula for substituting into PI control, obtains To the PI control result out of current control period₁₂[1], by the control margin of error in of current control period₁₃[1], a upper control The control margin of error in period₁₃[0], the PI control result out in a upper control period₁₃[0] the discrete computing table of PI control is substituted into Up to formula, the PI control result out of current control period is obtained₁₃[1]；

S40, to PI control result out₁₂[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned To VT in #5 converter_5CThe duty ratio D of pipe_5C, to PI control result out₁₃[1] clipping is carried out, is limited between zero and one, And the result after clipping is assigned to VT in #5 converter_5DThe duty ratio D of pipe_5D, VT in #5 converter_5AThe duty ratio D of pipe_5A, #5 become VT in parallel operation_5BThe duty ratio D of pipe_5BIt is assigned a value of 0.

Further, BOOST converter group is at MPPT operating mode, two-way DC/DC converter when system starts In BUCK operating mode, energy storage device charging.If the peak power output of photovoltaic array is greater than charge required power and load institute The sum of power is needed, DC bus-bar voltage will be higher than busbar voltage reference value after starting a period of time, at this moment BOOST converter group Controller will automatically switch to constant voltage output control, make photovoltaic array output with charge needed for power and load needed for power The sum of equal power, to guarantee that DC bus-bar voltage is consistent with busbar voltage reference value.If the maximum output of photovoltaic array Power is less than charge the sum of required power and power needed for load, but is greater than the required power of load, then needs to cut off two-way DC/DC Converter group；If the peak power output of photovoltaic array, which is less than, loads required power, two-way DC/DC converter is needed to be in BOOST operating mode, energy storage device electric discharge, while photovoltaic array needs to be constantly in MPPT operating mode.

Size relation between power needed for power, charging as needed for can not directly compare peak power output and load, So control model can only be carried out to BOOST converter group and two-way DC/DC converter group by the judgement of other conditions Switching, to guarantee that DC bus-bar voltage is consistent with busbar voltage reference value.

As shown in fig. 7, the mode of BOOST converter group and two-way DC/DC converter group coordinate the following steps are included:

S41, judge mode₁=1, mode₂=1, V_bus<V_refWhether three conditions are set up simultaneously, if set up simultaneously, By the variable x for being used to count from adding, S43 is otherwise skipped to；

Whether the x of S42, judgement from after adding is greater than 2000, if it is greater than 2000, then by mode₂It is assigned a value of 0, disconnects switch S4, S5 make energy storage device be in excision stand-by state, and x are reset；

S43, judge mode₁=1, mode₂=0, V_bus<V_refWhether three conditions are set up simultaneously, if set up simultaneously, By the variable y for being used to count from adding, S45 is otherwise skipped to；

Whether the y of S44, judgement from after adding is greater than 2000, if it is greater than 2000, then by mode₂2 are assigned a value of, and is closed and opens S4, S5 are closed, so that energy storage device is in discharge condition, and y is reset；

S45, end mode coordinated control.

In order to verify the feasibility of proposed control algolithm, built in PLECS simulated environment and circuit shown in Fig. 1 Consistent simulation model.Busbar voltage reference value is set to 72V always, and charging current reference value when energy storage device charges is 2A.Circuit element design parameter is as shown in table 1, table 2, table 3.3 photovoltaic arrays are connected by 54 photovoltaic cells.3 The intensity for the light that photovoltaic array receives is identical.Two energy storage devices are reduced to the voltage source and 0.5 that voltage value is 50V The concatenated equivalent model of the resistance of Ω.

Element names

L1

L2

L3

L4A

L4B

L5A

L5B

Inductance value

2mH

2mH

2mH

3mH

3mH

3mH

3mH

Table 1

Element names

C1

C2

C3

C4A

C4B

C5A

C5B

Capacitance

1880μF

1880μF

1880μF

1880μF

1880μF

1880μF

1880μF

Table 2

Element names	r1	r2	r3	r4	r5
						Resistance value	0.2Ω	0.7Ω	1.2Ω	0.5Ω	1Ω

Table 3

In order to verify the validity of proposed control strategy, it is prominent that load has been carried out in the PLECS simulation model built So increase the emulation of situation.Simulated conditions are as follows: intensity of illumination is always 1000 luxs, and ohmic load R is 30 Ω, switch S6 Entire simulation process is closure, so resistance R whole process is in access state.0~1.5s switch S7 is disconnected, and 1.5s is opened later It closes S7 and is in closed state, so constant power load is in access state after 1.5s.Needed for 1.5~2.5s constant power load Power is 300W, and power needed for constant power load is 500W after 2.5s.Under the simulated conditions, obtain such as Fig. 8, Fig. 9, figure 10, simulation result shown in Figure 11.

As shown in figure 8, under BOOST converter is in constant voltage output control model before constant power load accesses, it is two-way DC/DC converter is under BUCK operating mode, and energy storage device is under charged state, and DC bus-bar voltage is stablized in 72V.t₁ The access of moment (1.5s) constant power load, DC bus-bar voltage start to fall, and arrive t₂Moment controller detects DC bus electricity Press it is 3V also fewer than busbar voltage reference value, so controller automatically by the control mode switch of BOOST converter extremely MPPT control model.But the sum of power needed for the maximum power exported as photovoltaic array is less than all loads, busbar voltage according to So dropping.Meet mode simultaneously at this time₁=1, mode₂=1, V_bus<V_refThree conditions, x are started counting.t₃The value of moment x is big In 2000, controller has cut off two-way DC/DC converter, and energy storage device stops charging.Cut off bus after two-way DC/DC converter Voltage starts to rise rapidly, and busbar voltage has been greater than busbar voltage reference value quickly, and m is started counting, t₄The value of moment m is greater than 100, the control mode switch of BOOST converter group is constant voltage output control model by controller.DC bus-bar voltage gradually under Drop is finally controlled in busbar voltage reference value.t₅Power needed for moment (2.5s) constant power load increases to 500W by 300W, DC bus-bar voltage gradually falls, and arrives t₆Moment controller detect DC bus-bar voltage than busbar voltage reference value also than Few 3V, so controller is automatically by the control mode switch of BOOST converter to MPPT control model.But since photovoltaic array is defeated The sum of power needed for maximum power out is less than all loads, busbar voltage is still dropping.Meet mode simultaneously at this time₁=1, mode₂=0, V_bus<V_refThree conditions, y are started counting.t₇The value of moment y is greater than 2000, and controller has accessed two-way DC/ again DC converter, and be at BOOST operating mode, energy storage device are in discharge condition by two-way DC/DC converter to straight Flow bus injecting power.Controller forces BOOST converter group in MPPT control model by the way that se is set 1 at this time.? Under the adjusting of controller, DC bus-bar voltage is about stabilized in setting reference value after 3.1s.

The waveform of the output electric current of three BOOST converters is as shown in figure 9, although 3 BOOST converters and DC bus Between line resistance it is different, but when BOOST converter group is using constant voltage output control model and reaching stable state, it Output electric current be it is essentially equal, stream precision it is higher.t₆The MPPT that BOOST converter uses after moment controls mould Formula, thus the power of three photovoltaic arrays output be it is identical, output power can be depleted a part on line resistance, route Resistance is bigger, is lost also bigger.Therefore the output electric current of #1 converter is greater than the output electric current of #2 converter, #2 transformation after 3s The output electric current of device is greater than the output electric current of #3 converter.

The output electric current of two-way DC/DC converter is as shown in Figure 10.t₃Two-way DC/DC converter is in BUCK before moment Operating mode, energy storage device is in charged state, therefore input current is negative value；t₃To t₇Between, two-way DC/DC converter quilt Excision, input current 0；t₇Two-way DC/DC converter is accessed again and in BOOST operating mode, energy storage after moment Equipment is in discharge condition, therefore exporting electric current is positive value.The output electric current of two converters of whole process is identical, causes Current waveform essentially coincides.

The output electric current of energy storage device is as shown in figure 11.t₃Energy storage device is in charged state before moment, therefore inputs Electric current is negative value, and and control in given current reference value 2A, control precision is higher；t₃To t₇Between, energy storage device is in spare State, input current 0；t₇Energy storage device is in discharge condition after moment, therefore exporting electric current is positive value.

The emulation of light intensity decreasing situation has been carried out in the PLECS simulation model built.Simulated conditions are as follows: ohmic load R is 17 Ω, and the entire simulation process of switch S6 is closure, so resistance R whole process is in access state, switch S7 is in always Off-state.0~1.5s intensity of illumination is always 1000 luxs, and 1.5s~2.5s intensity of illumination is 600 luxs, 2.5s with Intensity of illumination is 300 luxs afterwards.Under the simulated conditions, obtain such as Figure 12, Figure 13, Figure 14, emulation shown in figure 15 knot Fruit.

As shown in figure 12, under BOOST converter is in constant voltage output control model before the 1.5s, two-way DC/DC transformation Device is under BUCK operating mode, and energy storage device is under charged state, and DC bus-bar voltage is stablized in 72V.t₈Moment (1.5s) intensity of illumination becomes 600 luxs, and DC bus-bar voltage starts to fall, and arrives t₉Moment controller detects DC bus Voltage is 3V also fewer than busbar voltage reference value, thus controller automatically by the control mode switch of BOOST converter extremely MPPT control model.But the sum of power needed for the maximum power exported as photovoltaic array is less than all loads, busbar voltage according to So dropping.Meet mode simultaneously at this time₁=1, mode₂=1, V_bus<V_refThree conditions, x are started counting.t₁₀The value of moment x Greater than 2000, controller has cut off two-way DC/DC converter, and energy storage device stops charging.Cut off two-way DC/DC converter stepmother Line voltage starts to rise rapidly, and busbar voltage has been greater than busbar voltage reference value quickly, and m is started counting, t₁₁The value of moment m is greater than 100, the control mode switch of BOOST converter group is constant voltage output control model by controller.DC bus-bar voltage gradually under Drop is finally controlled in busbar voltage reference value.t₁₂Moment (2.5s) intensity of illumination becomes 300 luxs, DC bus-bar voltage by Step is fallen, and t is arrived₁₃Moment controller detects that DC bus-bar voltage is 3V also fewer than busbar voltage reference value, so control Device is automatically by the control mode switch of BOOST converter to MPPT control model.But due to the maximum power of photovoltaic array output Less than the sum of power needed for all loads, busbar voltage is still dropping.Meet mode simultaneously at this time₁=1, mode₂=0, V_bus< V_refThree conditions, y are started counting.t₇The value of moment y is greater than 2000, and controller has accessed two-way DC/DC converter again, and It is at BOOST operating mode, energy storage device is in discharge condition and injects function to DC bus by two-way DC/DC converter Rate.Controller forces BOOST converter group in MPPT control model by the way that se is set 1 at this time.In the adjusting of controller Under, DC bus-bar voltage is about stabilized in setting reference value in 2.8s.

The waveform of the output electric current of three BOOST converters is as shown in figure 13, although 3 BOOST converters and direct current are female Line resistance between line is different, but works as BOOST converter group using constant voltage output control model and reach stable state, Their output electric current be it is essentially equal, stream precision it is higher.

The output electric current of two-way DC/DC converter is as shown in figure 14.t₁₀Two-way DC/DC converter is in BUCK before moment Operating mode, energy storage device is in charged state, therefore input current is negative value；t₁₀To t₁₄Between, two-way DC/DC converter It is removed, input current 0；t₁₄Two-way DC/DC converter is accessed again and in BOOST operating mode, storage after moment Energy equipment is in discharge condition, therefore exporting electric current is positive value.

The output electric current of energy storage device is as shown in figure 15.t₁₀Energy storage device is in charged state before moment, therefore inputs Electric current is negative value, and and control in given current reference value 2A, control precision is higher；t₁₀To t₁₄Between, energy storage device is in standby With state, input current 0；t₇Energy storage device is in discharge condition after moment, therefore exporting electric current is positive value.

The above simulation result absolutely proves that control method proposed by the present invention can have photovoltaic array and energy storage device Integrating for machine provides a reliable energy source for load, the benefit of maximal efficiency while guaranteeing that DC bus is stablized With the received solar energy of photovoltaic array, in light intensity decreasing, load sudden change etc., controller can make quick tune in special circumstances The whole stabilization to guarantee DC bus-bar voltage.

Those of ordinary skill in the art will understand that the embodiments described herein, which is to help reader, understands this hair Bright principle, it should be understood that protection scope of the present invention is not limited to such specific embodiments and embodiments.This field Those of ordinary skill can according to the present invention disclosed the technical disclosures make it is various do not depart from essence of the invention other are each Kind specific variations and combinations, these variations and combinations are still within protection scope of the present invention.

Claims (9)

1. a kind of photovoltaic DC electricity generation system with energy storage device, which is characterized in that become including 3 photovoltaic arrays, 3 BOOST Parallel operation, 2 energy storage devices, 2 two-way DC/DC converters, an ohmic load, a constant power load, 3 photovoltaic arrays are equal It is connected in series by 54 solar batteries, is respectively designated as the first photovoltaic array, the second photovoltaic array, third photovoltaic array, 3 Photovoltaic array is by the way that, again to DC bus injecting power, 3 BOOST converters are respectively designated as # after BOOST converter boosting 1 converter, #2 converter, #3 converter, and it is classified as BOOST converter group, there are two types of control models for BOOST converter, respectively It is constant voltage output control model and MPPT control model；2 energy storage devices are respectively designated as the 4th energy storage device and the 5th energy storage Equipment, energy storage device have 3 working conditions, are constant-current charge state, excision stand-by state, discharge condition, energy storage device respectively It crosses two-way DC/DC converter to be connected with DC bus, 2 two-way DC/DC converters are respectively designated as #4 converter, #5 transformation Device, and be classified as two-way DC/DC converter group, two-way DC/DC converter there are three types of operating mode, respectively BOOST operating mode, BUCK operating mode, excision model, when two-way DC/DC converter is in BOOST operating mode, energy storage device is in electric discharge shape State；When two-way DC/DC converter is in BUCK operating mode, energy storage device is in constant-current charge state, when two-way DC/DC becomes When parallel operation is in excision model, energy storage device is in excision stand-by state.

2. the control method of the photovoltaic DC electricity generation system with energy storage device, which is characterized in that be divided into two layers, indsole The purpose of layer is that the control BOOST converter group being connected with photovoltaic battery array and the two-way DC/DC being connected with energy storage device become Parallel operation group, the purpose of top layer are to coordinate BOOST converter group and two-way DC/DC converter group, make DC bus-bar voltage in illumination The stabilization of DC bus-bar voltage, the control week of the control algolithm of the system are able to achieve when Intensity Abrupt, load sudden change Phase ts is 0.00005s, therefore primary complete control calculates and needs to complete in 0.00005s, completes a control algolithm meeting Obtain 11 duty ratios, respectively D₁、D₂、D₃、D_4A、D_4B、D_4C、D_4D、D_5A、D_5B、D_5C、D_5D, then 11 PWM modules are according to this 11 duty ratio modulations go out corresponding pwm signal, respectively PWM₁、PWM₂、PWM₃、PWM_4A、PWM_4B、PWM_4C、PWM_4D、 PWM_5A、PWM_5B、PWM_5C、PWM_5D, wherein PWM₁Signal is for controlling VT in #1 converter₁Pipe turns on and off, PWM₂Signal For controlling VT in #2 converter₂Pipe turns on and off, PWM₃Signal is for controlling VT in #3 converter₃Pipe being opened and closing It is disconnected, PWM_4A、PWM_4B、PWM_4C、PWM_4DSignal is for controlling VT in #4 converter_4A、VT_4B、VT_4C、VT_4DPipe turns on and off, PWM_5A、PWM_5B、PWM_5C、PWM_5DSignal is for controlling VT in #5 converter_5A、VT_5B、VT_5C、VT_5DPipe turns on and off.

3. the control method of the photovoltaic DC electricity generation system according to claim 2 with energy storage device, which is characterized in that it Bottom control include two large divisions, the control of BOOST converter group and the control of two-way DC/DC converter, BOOST converter Group is there are two types of control model, and there are three types of control models for two-way DC/DC converter, and mode is arranged₁For the work of BOOST converter group Scheme control position, works as mode₁When being 1,3 BOOST converters are all made of MPPT control, work as mode₁When being 0,3 BOOST transformation Device is all made of constant voltage output control, and mode is arranged₂For the operating mode control bit of two-way DC/DC converter group, work as mode₂It is 1 When, two-way DC/DC converter group is in BUCK operating mode, and energy storage device is in constant-current charge state；Work as mode₂It is double when being 2 It is in BOOST operating mode to DC/DC converter group, energy storage device is in discharge condition；Work as mode₂When being 0, two-way DC/DC Converter group is in excision state, and energy storage device is in excision stand-by state.

4. the control method of the photovoltaic DC electricity generation system according to claim 3 with energy storage device, which is characterized in that when mode₁When being 1, BOOST converter group is controlled using MPPT, and MPPT control can divide in the control controlled in the period a calculating For following steps:

S1, the output voltage V for reading the first photovoltaic array of current control period₁, output electric current I₁；

S2, the output voltage difference DELTA V for calculating the first photovoltaic array between current control period and a upper control period₁, output electricity The difference DELTA I of stream₁；

S3, as Δ V₁With Δ I₁When being 0, the duty ratio D of #1 converter₁It is consistent with a upper control period；As Δ V₁The Δ for 0 I₁When greater than 0, the duty ratio D of #1 converter₁The duty ratio that the period is controlled than upper one increases Δ d, and Δ d is duty ratio Tiny increment dt, The present invention sets it to 0.0001；As Δ V₁The Δ I for 0₁When less than 0, the duty ratio D of #1 converter₁Than upper control week The duty ratio of phase reduces Δ d；As Δ I₁/ΔV₁=I₁/V₁When, the duty ratio D of #1 converter₁It is consistent with a upper control period； As Δ I₁/ΔV₁>I₁/V₁When, the duty ratio D of #1 converter₁The duty ratio that the period is controlled than upper one reduces Δ d；As Δ I₁/Δ V₁<I₁/V₁When, the duty ratio D of #1 converter₁The duty ratio that the period is controlled than upper one increases Δ d；

S4, judge se=0 and V_bus>V_refWhether two conditions are set up simultaneously, and wherein se is that the control of BOOST converter group is enabled Position, when se is 0, BOOST converter group can be between two kinds of control models of MPPT control model and constant voltage output control model Free switching, when se is 1, BOOST converter group is locked under MPPT control model, V_busFor bus voltage value, V_ref For busbar voltage reference value, after two conditions meet simultaneously, for m from adding, m is counting variable, then judges whether m is greater than 100, When m is greater than 100, by mode₁It is assigned a value of 0, the operating mode of converter group is made to be switched to constant voltage output control model, and by m It resets；

S5, the output voltage V for reading the second photovoltaic array of current control period₂, output electric current I₂；

S6, the output voltage difference DELTA V for calculating the second photovoltaic array between current control period and a upper control period₂, output electricity The difference DELTA I of stream₂；

S7, as Δ V₂With Δ I₂When being 0, the duty ratio D of #2 converter₂It is consistent with a upper control period；As Δ V₂The Δ for 0 I₂When greater than 0, the duty ratio D of #2 converter₂The duty ratio that the period is controlled than upper one increases Δ d；As Δ V₂The Δ I for 0₂It is small When 0, the duty ratio D of #2 converter₂The duty ratio that the period is controlled than upper one reduces Δ d；As Δ I₂/ΔV₂=I₂/V₂When, #2 The duty ratio D of converter₂It is consistent with a upper control period；As Δ I₂/ΔV₂>I₂/V₂When, the duty ratio D of #2 converter₂Than upper The duty ratio in one control period reduces Δ d；As Δ I₂/ΔV₂<I₂/V₂When, the duty ratio D of #1 converter₂It is controlled than upper one The duty ratio in period increases Δ d；

S8, the output voltage V for reading current control period third photovoltaic array₃, output electric current I₃；

S9, the output voltage difference DELTA V for calculating third photovoltaic array between current control period and a upper control period₃, output electricity The difference DELTA I of stream₃；

S10, as Δ V₃With Δ I₃When being 0, the duty ratio D of #3 converter₃It is consistent with a upper control period；As Δ V₃For 0 ΔI₃When greater than 0, the duty ratio D of #3 converter₃The duty ratio that the period is controlled than upper one increases Δ d；As Δ V₃The Δ I for 0₃ When less than 0, the duty ratio D of #3 converter₃The duty ratio that the period is controlled than upper one reduces Δ d；As Δ I₃/ΔV₃=I₃/V₃ When, the duty ratio D of #3 converter₃It is consistent with a upper control period；As Δ I₃/ΔV₃>I₃/V₃When, the duty ratio of #3 converter D₃The duty ratio that the period is controlled than upper one reduces Δ d；As Δ I₃/ΔV₃<I₃/V₃When, the duty ratio D of #3 converter₃Than upper one The duty ratio in a control period increases Δ d.

5. the control method of the photovoltaic DC electricity generation system according to claim 3 with energy storage device, which is characterized in that when mode₁When being 0, BOOST converter group is controlled using constant voltage output, the control meter that constant voltage output control controls in the period at one Calculation can be divided into following steps:

S11, busbar voltage reference value V is calculated_refWith bus voltage value V_busDifference, and difference is assigned in₁[1], in₁Array In₁That [1] store is the control margin of error of current control period, in₁[0] storage is the upper one control error for controlling the period Amount, out₁The out of array₁That [1] store is the PI control result of current control period, out₁[0] storage was upper control week The PI control result of phase；

S12, PI control operation is carried out, by the control margin of error in of current control period₁[1], the control error in a upper control period Measure in₁[0], the PI control result out in a upper control period₁[0] the discrete computing expression formula (1) for substituting into PI control obtains current Control the PI control result out in period₁[1]；

S13, to PI control result out₁[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned to #1 The duty ratio D of converter₁；

S14, judge V_bus<V_ref- 3 and se be equal to 0 the two conditions it is whether true, as long as in two conditions any one condition at It is vertical, just by mode₁1 is set, converter group is switched to MPPT control model；

S15, the output electric current I for calculating #1 converter₁The output electric current I of _ out and #2 converter₂The difference of _ out, and by difference It is assigned in₂[1], in₂The in of array₂That [1] store is the control margin of error of current control period, in₂[0] storage is upper one Control the control margin of error in period, out₂The out of array₂That [1] store is the PI control result of current control period, out₂[0] Storage is the upper one PI control result for controlling the period；

S16, PI control operation is carried out, by the control margin of error in of current control period₂[1], the control error in a upper control period Measure in₂[0], the PI control result out in a upper control period₂[0] the discrete computing expression formula (2) for substituting into PI control obtains current Control the PI control result out in period₂[1]；

S17, to PI control result out₂[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned to #2 The duty ratio D of converter₂；

S18, the output electric current I for calculating #3 converter₁The output electric current I of _ out and #3 converter₃The difference of _ out, and by difference It is assigned in₃[1], in₃The in of array₃That [1] store is the control margin of error of current control period, in₃[0] storage is upper one Control the control margin of error in period, out₃The out of array₃That [1] store is the PI control result of current control period, out₃[0] Storage is the upper one PI control result for controlling the period；

S19, third time PI control operation is carried out, by the control margin of error in of current control period₃[1], the control in a upper control period Margin of error in processed₃[0], the PI control result out in a upper control period₃[0] the discrete computing expression formula (3) for substituting into PI control, obtains To the PI control result out of current control period₃[1]；

S20, to PI control result out₃[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned to #3 The duty ratio D of converter₃。

6. the control method of the photovoltaic DC electricity generation system according to claim 3 with energy storage device, which is characterized in that when mode₂When being 1, two-way DC/DC converter group is in BUCK operating mode, in the control that one controls in the period under the operating mode System, which calculates, to be divided into following steps:

S21, due to charging when, the direction of inductive current and the positive direction of setting are on the contrary, so need inductance L_4a、L_4bIn flow through Electric current I_4a、I_4bIt negates；

S22, I is calculated_{R_in}/ 2 and I_4aDifference, and difference is assigned in₄[1], I is calculated_{R_in}/ 2 and I_4bDifference, and by difference It is assigned in₅[1], I_{R_in}For the charging current reference value of energy storage device, in₄The in of array₄[1] storage is current control period The control margin of error, in₄[0] that storage is the upper one control margin of error for controlling the period, out₄The out of array₄[1] storage is The PI control result of current control period, out₄[0] that storage is the upper one PI control result for controlling the period, in₅The in of array₅ That [1] store is the control margin of error of current control period, in₅[0] storage is the upper one control margin of error for controlling the period, out₅The out of array₅That [1] store is the PI control result of current control period, out₅[0] storage was a upper control period PI control result；

S23, PI control operation is carried out, by the control margin of error in of current control period₄[1], the control error in a upper control period Measure in₄[0], the PI control result out in a upper control period₄[0] the discrete computing expression formula (4) for substituting into PI control obtains current Control the PI control result out in period₄[1], by the control margin of error in of current control period₅[1], the control in a upper control period Margin of error in processed₅[0], the PI control result out in a upper control period₅[0] the discrete computing expression formula (5) for substituting into PI control, obtains To the PI control result out of current control period₅[1]；

S24, to PI control result out₄[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned to #4 VT in converter_4AThe duty ratio D of pipe_4A, to PI control result out₅[1] clipping is carried out, is limited between zero and one, and will limit Result after width is assigned to VT in #4 converter_4BThe duty ratio D of pipe_4B, VT in #4 converter_4CThe duty ratio D of pipe_4C, in #4 converter VT_4DThe duty ratio D of pipe_4DIt is assigned a value of 0；

S25, due to charging when, the direction of inductive current and the positive direction of setting are on the contrary, so need inductance L_5a、L_5bIn flow through Electric current I_5a、I_5bIt negates；

S26, I is calculated_{R_in}/ 2 and I_5aDifference, and difference is assigned in₉[1], I is calculated_{R_in}/ 2 and I_5bDifference, and by difference It is assigned in₁₀[1], in₉The in of array₉That [1] store is the control margin of error of current control period, in₉[0] storage is upper one Control the control margin of error in period, out₉The out of array₉That [1] store is the PI control result of current control period, out₉[0] Storage is the upper one PI control result for controlling the period, in₁₀The in of array₁₀[1] what is stored is the control mistake of current control period Residual quantity, in₁₀[0] that storage is the upper one control margin of error for controlling the period, out₁₀The out of array₁₀[1] storage is currently to control The PI control result in period processed, out₁₀[0] storage is the upper one PI control result for controlling the period；

S27, PI control operation is carried out, by the control margin of error in of current control period₉[1], the control error in a upper control period Measure in₉[0], the PI control result out in a upper control period₉[0] the discrete computing expression formula (9) for substituting into PI control obtains current Control the PI control result out in period₉[1], by the control margin of error in of current control period₁₀[1], the control in a upper control period Margin of error in processed₁₀[0], the PI control result out in a upper control period₁₀[0] the discrete computing expression formula of PI control is substituted into (10), the PI control result out of current control period is obtained₁₀[1]；

S28, to PI control result out₉[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned to #5 VT in converter_5AThe duty ratio D of pipe_5A, to PI control result out₁₀[1] clipping is carried out, is limited between zero and one, and will Result after clipping is assigned to VT in #5 converter_5BThe duty ratio D of pipe_5B, VT in #5 converter_5CThe duty ratio D of pipe_5C, #5 converter Middle VT_5DThe duty ratio D of pipe_5DIt is assigned a value of 0.

7. the control method of the photovoltaic DC electricity generation system according to claim 3 with energy storage device, which is characterized in that when mode₂When being 2, two-way DC/DC converter group is in BOOST operating mode, within a control period under the operating mode Control, which calculates, to be divided into following steps:

S29, busbar voltage reference value V is calculated_refWith bus voltage value V_busDifference, and difference is assigned in₆[1], in₆Array In₆That [1] store is the control margin of error of current control period, in₆[0] storage is the upper one control error for controlling the period Amount, out₆The out of array₆That [1] store is the PI control result of current control period, out₆[0] storage was upper control week The PI control result of phase；

S30, PI control operation is carried out, by the control margin of error in of current control period₆[1], the control error in a upper control period Measure in₆[0], the PI control result out in a upper control period₆[0] the discrete computing expression formula (6) for substituting into PI control obtains current Control the PI control result out in period₆[1]；

S31, by out₆[1] it is assigned to I_{R_out4}, I_{R_out4}For the output current reference value of energy storage device；

S32, I is calculated_{R_out4}/ 2 and I_4aDifference, and difference is assigned in₇[1], I is calculated_{R_out4}/ 2 and I_4bDifference, and will be poor Value is assigned in₈[1], I_{R_out4}For the output current reference value of energy storage device, in₇The in of array₇[1] storage is current control week The control margin of error of phase, in₇[0] that storage is the upper one control margin of error for controlling the period, out₇The out of array₇[1] it stores It is the PI control result of current control period, out₇[0] that storage is the upper one PI control result for controlling the period, in₈Array in₈That [1] store is the control margin of error of current control period, in₈[0] storage is the upper one control margin of error for controlling the period, out₈The out of array₈That [1] store is the PI control result of current control period, out₈[0] storage was a upper control period PI control result；

S33, PI control operation is carried out, by the control margin of error in of current control period₇[1], the control error in a upper control period Measure in₇[0], the PI control result out in a upper control period₇[0] the discrete computing expression formula (7) for substituting into PI control obtains current Control the PI control result out in period₇[1], by the control margin of error in of current control period₈[1], the control in a upper control period Margin of error in processed₈[0], the PI control result out in a upper control period₈[0] the discrete computing expression formula (8) for substituting into PI control, obtains To the PI control result out of current control period₈[1]；

S34, to PI control result out₇[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned to #4 VT in converter_4CThe duty ratio D of pipe_4C, to PI control result out₈[1] clipping is carried out, is limited between zero and one, and will limit Result after width is assigned to VT in #4 converter_4DThe duty ratio D of pipe_4D, VT in #4 converter_4AThe duty ratio D of pipe_4A, in #4 converter VT_4BThe duty ratio D of pipe_4BIt is assigned a value of 0；

S35, #4 converter output electric current I is calculated_{4_}Out and #5 converter export electric current I_{5_}The difference of out, and difference is assigned to in₁₁[1], in₁₁The in of array₁₁That [1] store is the control margin of error of current control period, in₁₁[0] storage is a upper control The control margin of error in period processed, out₁₁The out of array₁₁That [1] store is the PI control result of current control period, out₁₁[0] Storage is the upper one PI control result for controlling the period；

S36, PI control operation is carried out, by the control margin of error in of current control period₁₁[1], the control in a upper control period misses Residual quantity in₁₁[0], the PI control result out in a upper control period₁₁[0] the discrete computing expression formula (11) for substituting into PI control, obtains To the PI control result out of current control period₁₁[1]；

S37, by I₄It is superimposed with out₁₁[1] I is obtained_{R_out5}, I_{R_out5}For the output current reference value of the 5th energy storage device；

S38, I is calculated_{R_out5}/ 2 and I_5aDifference, and difference is assigned in₁₂[1], I is calculated_{R_out5}/ 2 and I_5bDifference, and will Difference is assigned in₁₃[1], I_{R_out5}For the output current reference value of the 5th energy storage device, in₁₂The in of array₁₂[1] storage is to work as The control margin of error in preceding control period, in₁₂[0] that storage is the upper one control margin of error for controlling the period, out₁₂The out of array₁₂ That [1] store is the PI control result of current control period, out₁₂[0] storage is the upper one PI control result for controlling the period, in₁₃The in of array₁₃That [1] store is the control margin of error of current control period, in₁₃[0] storage was a upper control period Control the margin of error, out₁₃The out of array₁₃That [1] store is the PI control result of current control period, out₁₃[0] storage is The PI control result in a upper control period；

S39, PI control operation is carried out, by the control margin of error in of current control period₁₂[1], the control in a upper control period misses Residual quantity in₁₂[0], the PI control result out in a upper control period₁₂[0] the discrete computing expression formula (12) for substituting into PI control, obtains To the PI control result out of current control period₁₂[1], by the control margin of error in of current control period₁₃[1], a upper control The control margin of error in period₁₃[0], the PI control result out in a upper control period₁₃[0] the discrete computing table of PI control is substituted into Up to formula (13), the PI control result out of current control period is obtained₁₃[1]；

S40, to PI control result out₁₂[1] clipping is carried out, is limited between zero and one, and the result after clipping is assigned to #5 VT in converter_5CThe duty ratio D of pipe_5C, to PI control result out₁₃[1] clipping is carried out, is limited between zero and one, and will Result after clipping is assigned to VT in #5 converter_5DThe duty ratio D of pipe_5D, VT in #5 converter_5AThe duty ratio D of pipe_5A, #5 converter Middle VT_5BThe duty ratio D of pipe_5BIt is assigned a value of 0.

8. the control method of the photovoltaic DC electricity generation system according to claim 2 with energy storage device, which is characterized in that it Top layer control the following steps are included:

S41, judge mode₁=1, mode₂=1, V_bus<V_refWhether three conditions are set up simultaneously, if set up simultaneously, will use In the variable x of counting from adding, S43 is otherwise skipped to；

Whether the x of S42, judgement from after adding is greater than 2000, if it is greater than 2000, then by mode₂It is assigned a value of 0, disconnects switch S4, S5, So that energy storage device is in excision stand-by state, and x is reset；

S43, judge mode₁=1, mode₂=0, V_bus<V_refWhether three conditions are set up simultaneously, if set up simultaneously, will use In the variable y of counting from adding, S45 is otherwise skipped to；

Whether the y of S44, judgement from after adding is greater than 2000, if it is greater than 2000, then by mode₂It is assigned a value of 2, and closure switch S4, S5 makes energy storage device be in discharge condition, and y is reset；

S45, terminate top layer control.

9. the control method of the photovoltaic DC electricity generation system according to claim 5,6,7 with energy storage device, feature exist In, step S12, mentioned in S16, S19, S23, S27, S30, S33, S36, S39 PI control discrete expression (1)~(13) respectively Are as follows:

out₁[1]=(p₁+ts*i₁)*in₁[1]-p₁*in₁[0]+out₁[0] (1)

out₂[1]=(p₂+ts*i₂)*in₂[1]-p₂*in₂[0]+out₂[0] (2)

out₃[1]=(p₃+ts*i₃)*in₃[1]-p₃*in₃[0]+out₃[0] (3)

out₄[1]=(p₄+ts*i₄)*in₄[1]-p₄*in₄[0]+out₄[0] (4)

out₅[1]=(p₅+ts*i₅)*in₅[1]-p₅*in₅[0]+out₅[0] (5)

out₆[1]=(p₆+ts*i₆)*in₆[1]-p₆*in₆[0]+out₆[0] (6)

out₇[1]=(p₇+ts*i₇)*in₇[1]-p₇*in₇[0]+out₇[0] (7)

out₈[1]=(p₈+ts*i₈)*in₈[1]-p₈*in₈[0]+out₈[0] (8)

out₉[1]=(p₉+ts*i₉)*in₉[1]-p₉*in₉[0]+out₉[0] (9)

out₁₀[1]=(p₁₀+ts*i₁₀)*in₁₀[1]-p₁₀*in₁₀[0]+out₁₀[0] (10)

out₁₁[1]=(p₁₁+ts*i₁₁)*in₁₁[1]-p₁₁*in₁₁[0]+out₁₁[0] (11)

out₁₂[1]=(p₁₂+ts*i₁₂)*in₁₂[1]-p₁₂*in₁₂[0]+out₁₂[0] (12)

out₁₃[1]=(p₁₃+ts*i₁₃)*in₁₃[1]-p₁₃*in₁₃[0]+out₁₃[0] (13)

Wherein p₁For the first proportionality coefficient, i₁For first integral coefficient, ts is the control period；p₂For the second proportionality coefficient, i₂It is Two integral coefficients；p₃For third proportionality coefficient, i₃For third integral coefficient；p₄For the 4th proportionality coefficient, i₄For the 4th integration system Number；p₅For the 5th proportionality coefficient, i₅For the 5th integral coefficient；p₆For the 6th proportionality coefficient, i₆For the 6th integral coefficient；p₇It is the 7th Proportionality coefficient, i₇For the 7th integral coefficient；p₈For the 8th proportionality coefficient, i₈For the 8th integral coefficient；p₉For the 9th proportionality coefficient, i₉ For the 9th integral coefficient；p₁₀For the tenth proportionality coefficient, i₁₀For the tenth integral coefficient；p₁₁For the 11st proportionality coefficient, i₁₁It is the tenth One integral coefficient；p₁₂For the 12nd proportionality coefficient, i₁₂For the 12nd integral coefficient；p₁₃For the 13rd proportionality coefficient, i₁₃It is the tenth Three integral coefficients.