CN202474995U - Wind-solar-hybrid maximum power point tracking (MPPT) controller - Google Patents

Abstract

The utility model discloses a wind-solar-hybrid maximum power point tracking (MPPT) controller which comprises a Buck-Boost convertor utilizing a differential optimal-control method, a digital signal processor and a stepless electronic emptier which is connected with a photovoltaic assembly and a draught fan. An input end of the Buck-Boost convertor which is connected with the photovoltaic assembly and the draught fan is connected with an output end of the digital signal processor, and an output end of the Buck-Boost convertor is connected with an input ends of the digital signal processor and a storage battery pack at the same time. The input end of the digital signal processor receives source voltage which is generated by the photovoltaic assembly and the draught fan, and the output end of the digital signal processor is further connected with the stepless electronic emptier. The wind-solar-hybrid MPPT controller is rapid in tracking speed and can utilize wind-solar energy to the utmost.

Description

A kind of wind light mutual complementing MPPT controller

Technical field

The utility model relates to a kind of wind light mutual complementing MPPT controller, and it is applied in the wind-light complementary system.

Background technology

Solar energy, wind energy are the important compositions of new forms of energy, and the wind light mutual complementing controller is solar energy, wind energy key issue in application equipment.The wind light mutual complementing controller carries out intelligent charge, quick charge and maximum power charging safely and efficiently to storage battery; Be the emphasis problem of domestic and international numerous scientific workers' research, this is for improving and utilizing the efficient of solar energy, wind energy resources to have great significance always.

In the prior art; Wind light mutual complementing MPPT maximum power point tracking (MPPT) controller mainly contains constant voltage process (CVT) wind light mutual complementing controller, disturbance observation (PO) wind light mutual complementing controller, duty ratio method of perturbation (DRP) wind light mutual complementing controller, conductance increment method (IncCond) wind light mutual complementing controller and fuzzy logic method (FL) wind light mutual complementing controller and optimum gradient method (OG) wind light mutual complementing controller etc.

Yet, wind light mutual complementing MPPT maximum power point tracking of the prior art (MPPT) controller, its tracking velocity is slow, can't be with the energy maximum using of wind, light.

In view of the above-mentioned defective of prior art wind light mutual complementing MPPT maximum power point tracking (MPPT) controller, the inventor develops a kind of wind light mutual complementing MPPT controller that overcomes above-mentioned defective, and this case produces thus.

The utility model content

The purpose of the utility model is to provide a kind of tracking velocity fast and wind light mutual complementing MPPT controller that can the maximum using view energy source.

For reaching above-mentioned purpose, the solution of the utility model is:

A kind of wind light mutual complementing MPPT controller comprises Buck-Boost converter, digital signal processor that adopts the differential method in optimal control and the stepless electronics emptier that links to each other with blower fan with photovoltaic module; The input of the Buck-Boost converter that links to each other with photovoltaic module and blower fan is connected with the output of digital signal processor, and its output is connected with the input of digital signal processor and batteries simultaneously; The input of digital signal processor receives the source voltage of photovoltaic module and blower fan generation, and the output of digital signal processor also is connected with stepless electronics emptier; The signal of photovoltaic module and blower fan output gets into Buck-Boost converter and digital signal processor simultaneously; The signal of handling through the Buck-Boost converter gets into digital signal processor and batteries simultaneously; Signal after digital signal processor processes feeds back to stepless electronics emptier and Buck-Boost converter simultaneously.

Further, the Buck-Boost converter comprises MOS electronic switch, fly-wheel diode, inductor and capacitor; Parallelly connected with inductor behind fly-wheel diode and the capacitor series, the MOS electronic switch is serially connected in the circuit, and circuit is connected two poles.

After adopting such scheme; The utility model adopts maximum power point disturbance search to the power characteristic of blower fan and photovoltaic module; When if the input voltage of honourable power supply is equal to or less than the voltage of storage battery; Each control program all calls the MPPT control program of differential method in optimal control, the energy maximum using of scene.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is the utility model fan blade power coefficient C _ρ-tip speed ratio λ performance chart;

Fig. 3 is the utility model fan blade power-speed curves figure;

Fig. 4 a, Fig. 4 b are I-V, the P-V performance diagrams under the utility model photovoltaic module intensity of illumination different situations;

Fig. 5 a, Fig. 5 b are I-V, the P-V performance diagrams under the utility model photovoltaic module variations injunction temperature situation;

Fig. 6 is the utility model Buck-Boost transformer configuration figure;

Fig. 7 is the program diagram of Buck-Boost converter operation differential method in optimal control;

Fig. 8 is the working procedure figure of the utility model system.

Label declaration

Buck-Boost converter 1 MOS electronic switch 11

Fly-wheel diode 12 inductors 13

Capacitor 14 power supplys 15

Digital signal processor 2 stepless electronics emptiers 3

Photovoltaic module 4 blower fans 5

Batteries 6

Embodiment

Below in conjunction with accompanying drawing and specific embodiment the utility model is done detailed explanation.

Consult Fig. 1 and shown in Figure 6, a kind of wind light mutual complementing MPPT controller that the utility model discloses comprises Buck-Boost converter 1, digital signal processor 2 that adopts the differential method in optimal control and the stepless electronics emptier 3 that links to each other with blower fan 5 with photovoltaic module 4.

The input of the Buck-Boost converter 1 that links to each other with photovoltaic module 4 and blower fan 5 is connected with the output of digital signal processor 2, and its output is connected with the input of digital signal processor 2 with batteries 6 simultaneously.

The input of digital signal processor 2 receives the source voltage of photovoltaic module 4 and blower fan 5 generations, and the output of digital signal processor 2 also is connected with stepless electronics emptier 3.

Photovoltaic module 4 gets into Buck-Boost converter 1 and digital signal processor 2 simultaneously with the signal of blower fan 5 outputs; Signal after Buck-Boost converter 1 is handled gets into digital signal processor 2 and batteries 6 simultaneously; Signal after digital signal processor 2 is handled feeds back to stepless electronics emptier 3 and Buck-Boost converter 1 simultaneously.

Wherein, Buck-Boost converter 1 comprises MOS electronic switch 11, fly-wheel diode 12, inductor 13 and capacitor 14; Parallelly connected with inductor 13 after fly-wheel diode 12 is connected in series with capacitor 14, MOS electronic switch 11 is serially connected in the circuit, and circuit is connected power supply 15 the two poles of the earth.

In wind and solar hybrid generating system, relative blower fan 5, the electric energy of photovoltaic module 4 outputs is relatively stable; Wind energy then changes apparent in view, and randomness is strong, and output voltage is unstable; When wind speed surpassed limit value, power output was excessive, if this moment also need be to charge in batteries; Just must lay down part power, avoid blower fan 5 to damage through stepless electronics emptier 3.The rotating speed of blower fan 5 is directly proportional with output voltage, just can know the operating state of blower fan 5 through detecting blower fan 5 output voltages.Batteries 6 is the energy storage devices in the wind and solar hybrid generating system; How in the shortest time, to be full of batteries 6; Be the central issue that control needs solution to batteries 6 chargings promptly with maximum power; The utility model adopts the differential method in optimal control to realize that maximum power to batteries 6 chargings, below details:

At first, can know that the input power of blower fan 5 is by aerodynamics:

Pv=1/2 ρ SV ³(1) in the formula: ρ-atmospheric density; The S-blower fan 5 blades swept area that facings the wind; V-gets into the blower fan 5 swept surfaces wind speed of air before.

Since the wind energy through the blade surfaces of revolution be not all can both absorb by blower fan 5 its power coefficient of definable C _ρ

C _ρWind power=P/P in the mechanical output/input impeller face of=blower fan 5 outputs _V(2)

So the output mechanical power of blower fan 5 is:

$P=P_v{C}_{\mathrm{\ρ}}=\frac{\mathrm{\π}}{8}\mathrm{\ρ}{D}^2{V}^3{C}_{\mathrm{\ρ}}---\left(3\right)$

In the formula: the diameter of D-blade.

Power coefficient C _ρBe the important parameter that characterizes blower fan 5 efficient, it and wind speed, blade rotational speed and blade diameter all have relation.For C is discussed _ρCharacteristic, introduce another important parameter tip speed ratio λ of blower fan 5, i.e. the ratio of vane tip linear velocity and wind speed,

$\mathrm{\λ}=\frac{\mathrm{R\ω}}{V}=\frac{\mathrm{\πRn}}{30V}---\left(4\right)$

In the formula: the radius of R-blade; The angular speed of ω-blade rotation;

--the rotating speed of blade.

Adopt the Wilson computation model can obtain reflecting the C of blade aeroperformance _ρ-λ curve, as shown in Figure 2.

According to C _ρ-λ curve can be derived the power output-speed curves of different wind speed lower blades with formula (3), and is as shown in Figure 3.

Can know that from Fig. 3 the power output-speed curves of blower fan 5 is a set of curves under the different wind speed.Simultaneously, the output voltage of the rotating speed of blower fan 5 and generator is a proportional relation.

Secondly, the power output of photovoltaic module 4 has very strong non-linear, and such environmental effects is very obvious, especially the influence of intensity of illumination and assembly junction temperature.Component voltage-electric current under the different illumination intensity (V-I) and voltage-power (V-P) characteristic curve are seen Fig. 4.I-V, P-V characteristic curve under the photovoltaic module 4 variations injunction temperature situation are seen Fig. 5.

Can know that from I-V, the P-V characteristic curve of photovoltaic module 4 power output of photovoltaic module 4 can change along with the variation of intensity of illumination and assembly junction temperature.In photovoltaic module 4, require the power output of assembly maximum usually, promptly system wants the peak power output point of ability trace component.Because the peak power output point of photovoltaic module 4 with the irregular change of environment, makes the working point of load be difficult to the peak power output point match with photovoltaic module 4.

For the peak power output point that makes photovoltaic module 4 working point real-time fitting (power output of photovoltaic module 4 is maximum) with load; Must between photovoltaic module 4 and load, add impedance transformer; Make the working point after the conversion just in time overlap with the peak power output point of assembly; Make the power output of assembly maximum, MPPT maximum power point tracking that Here it is (MPPT).This impedance transformer is exactly a Buck-Boost converter 1.

As shown in Figure 6, the utility model Buck-Boost converter 1 adopts buck-boost type, and the uncontrollable voltage transitions that wind energy and solar energy are exported becomes controlled output voltage, and the polarity and the input voltage of output voltage are opposite.The relation of output voltage U O and input voltage Ui is:

$\mathrm{<figure-callout\; id="0"\; label="U"\; filenames="120113091658.png"\; state="\{\{state\}\}">U</figure-callout>}0=-\frac{D}{1-D}\mathrm{Ui}(0<D<1)---\left(5\right)$

In the formula, D is a duty ratio.Suppose that MOS electronic switch cycle T equals switch conduction time T on and switch Toff deadline, that is: T=Ton+Toff, duty ratio D is:

$D=\frac{\mathrm{Ton}}{T}---\left(6\right)$

Can find out from formula 5: when D=0.5, when not considering device loss, the output voltage of buck-boost type DC/DC converter equals input voltage; When D＜0.5, output voltage is less than input voltage; When D＞0.5, output voltage is greater than input voltage.Therefore as long as according to input voltage regulation duty ratio D, just can convert uncontrollable input voltage to controlled output voltage.

In order to realize MPPT maximum power point tracking, Buck-Boost converter 1 needs fast the line trace of going forward side by side of search maximum power point, and its tracking adopts differential method in optimal control, and the differential optimal control algorithm is following:

Sampled value: battery tension U1, U2 ..., U (i-2), U (i-1)

Charging current 11, I2 ..., I (i-2), I (i-1)

Controlling value: duty ratio D1, D2 ..., D (i-2), D (i-1)

Calculate: charge in batteries power P 1, P2 ..., P (i-2), P (i-1),

Difference of charge power

ΔP(i-1)＝P(i-1)-P(i-2) i＝1，2，3，…，n，… (7)

Charge power secondary difference

Δ ²P(i-1)＝ΔP(i-1)-ΔP(i-2)i＝ 1，2，3，…，n，… (8)

The difference of controlling value D

ΔD(i-1)＝D(i-1)-D(i-2) i＝1，2，3，…，n，… (9)

The control expression formula:

As

When Δ P (i-1)=0, D (i)=D (i-1)+1/4 Δ D (i-1)

As

Replace first order differential with the single order difference in the algorithm, replace second-order differential with the second order difference.The single order difference representes to apply the variable quantity and the direction of control back parameter, and the second order difference is represented the acceleration that parameter changes, and high again exponent number is little to the Linear Control effect, so omit.Can judge the acceleration direction that applies the parameter variation of control back with second-order differential,, accelerate to optimize the speed of approaching to strengthen the dynamics and the direction of regulating.

The i time controlled quentity controlled variable D (i) depends on the i-1 time charge power variation delta P (i-1), when Δ P (i-1)＞0 time explanation also need continue to strengthen controlled quentity controlled variable, again according to the second order difference DELTA ²P (i-1) further segments the controlled quentity controlled variable that needs strengthen; When Δ P (i-1)＜0, just in time, need search in the other direction, and reduce controlled quentity controlled variable with aforementioned opposite, repeat no more.Above-mentioned control constant needs test again to confirm along with the difference of system parameters.

Digital signal processor 2 is through detect the voltage and current of batteries 6 in real time, carry out the differential optimal control algorithm realize the maximum power charging of batteries 6 and all fill, floating charge and tiny stream charging control.The charging control stage of batteries 6 is divided into: directly fill mode, floating charge mode, all fill mode and tiny stream fills mode.Directly the mode of filling is the starting stage of batteries 6 boost charges; The floating charge mode is the interstage of batteries 6 boost charges; The tiny stream mode of filling is the final stage of batteries 6 boost charges.Batteries 6 is because the terminal voltage of single lattice battery, the density of electrolyte and the difference of capacity can appear in the difference of manufactured materials and discharge, and is totally unfavorable to the use of storage battery, need carry out equalizing charge to storage battery at a distance from a period of time for this reason.

Because the floating charge mode of batteries 6, all fill mode and the tiny stream mode of filling be pressure limiting with or current-limiting mode under control; When input voltage during far above battery tension (input power is greater than power output); Be not suitable for MPPT control; When input voltage during, be fit to MPPT control smaller or equal to battery tension (input power is less than power output); Promptly directly fill very suitable MPPT control under the mode in the starting stage of batteries 6 boost charges; Directly fill the mode charge power and account for the overwhelming majority of batteries 6 whole boost charge power, adopt the differential method optimal control significance to be arranged for the intake that makes full use of blower fan 5 and assembly.

The working procedure of Buck-Boost converter 1 is as shown in Figure 7, and the utility model system working procedure is as shown in Figure 8; All fill control, floating charge control and tiny stream in batteries 6 fill in the control; When if the input voltage of honourable power supply equals to be lower than the voltage of storage battery; Each control program all can call the MPPT control program of differential method in optimal control, the maximized utilization of the energy of scene.And this situation; Voltage like weak wind output is lower; The power of cloudy day and early morning low light level output at dusk is less often to be run into, and the MPPT control of differential method in optimal control can give these faint electric power major parts to collect, and has improved the using energy source ability of wind light mutual complementing controller greatly.Under equal environmental condition and batteries 6 states, adopt the charging current raising 7-10% of the wind light mutual complementing controller of differential method in optimal control than common wind light mutual complementing controller.

The embodiment that the above is merely the utility model is not the restriction to this case design, and all equivalent variations of doing according to the design key of this case all fall into the protection range of this case.

Claims (2)

1. a wind light mutual complementing MPPT controller is characterized in that: comprise Buck-Boost converter, digital signal processor that adopts the differential method in optimal control and the stepless electronics emptier that links to each other with blower fan with photovoltaic module; The input of the Buck-Boost converter that links to each other with photovoltaic module and blower fan is connected with the output of digital signal processor, and its output is connected with the input of digital signal processor and batteries simultaneously; The input of digital signal processor receives the source voltage of photovoltaic module and blower fan generation, and the output of digital signal processor also is connected with stepless electronics emptier; The signal of photovoltaic module and blower fan output gets into Buck-Boost converter and digital signal processor simultaneously; The signal of handling through the Buck-Boost converter gets into digital signal processor and batteries simultaneously; Signal after digital signal processor processes feeds back to stepless electronics emptier and Buck-Boost converter simultaneously.

2. a kind of wind light mutual complementing MPPT controller as claimed in claim 1, it is characterized in that: the Buck-Boost converter comprises MOS electronic switch, fly-wheel diode, inductor and capacitor; Parallelly connected with inductor behind fly-wheel diode and the capacitor series, the MOS electronic switch is serially connected in the circuit, and circuit is connected two poles.

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