CN114069699B - Parallel-off-grid small hydropower station response control device and method - Google Patents

Parallel-off-grid small hydropower station response control device and method Download PDF

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CN114069699B
CN114069699B CN202111356691.5A CN202111356691A CN114069699B CN 114069699 B CN114069699 B CN 114069699B CN 202111356691 A CN202111356691 A CN 202111356691A CN 114069699 B CN114069699 B CN 114069699B
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power
small hydropower
hydropower station
grid
energy storage
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CN114069699A (en
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杨金东
刘红文
唐立军
李芳方
聂鼎
范黎涛
吴万军
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Electric Power Research Institute of Yunnan Power Grid Co Ltd
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Electric Power Research Institute of Yunnan Power Grid Co Ltd
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/04—Circuit arrangements for ac mains or ac distribution networks for connecting networks of the same frequency but supplied from different sources
    • H02J3/06—Controlling transfer of power between connected networks; Controlling sharing of load between connected networks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
    • H02J3/241—The oscillation concerning frequency
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/28—Arrangements for balancing of the load in a network by storage of energy
    • H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/388—Islanding, i.e. disconnection of local power supply from the network
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2300/00—Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20—The dispersed energy generation being of renewable origin
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E70/00—Other energy conversion or management systems reducing GHG emissions
    • Y02E70/30—Systems combining energy storage with energy generation of non-fossil origin

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Supply And Distribution Of Alternating Current (AREA)
  • Control Of Eletrric Generators (AREA)

Abstract

The application provides a parallel off-grid small hydropower station response control device and a method, wherein the method comprises the steps of generating a time-power-voltage correspondence table with a year duration according to station change historical monitoring data; monitoring the change of the output voltage, current and frequency of the small hydropower station in real time, and stabilizing the output frequency of the small hydropower station; the method comprises the steps of predicting the frequency change of a micro-grid after load power in the next moment is monitored in real time by analyzing the power increase and decrease of a small hydropower station at the off-grid moment and the power absorption or release of a bidirectional energy storage converter, sending a power absorption increasing or decreasing control command to the bidirectional energy storage converter according to the frequency change of the micro-grid, and simultaneously, enabling the small hydropower station to work according to a self control strategy; and (3) increasing or decreasing the value range of the time-power-voltage correspondence table for one year according to the value of increasing or decreasing the absorption power at the current moment, and iterating out the value range of the new external network synchronous power supply power so as to ensure the safe and stable operation of the micro-grid.

Description

Parallel-off-grid small hydropower station response control device and method
Technical Field
The application relates to the technical field of micro-grids, in particular to a parallel-off-grid small hydropower station response control device and method.
Background
With the rapid development of renewable energy power generation technology, energy storage technology, small hydropower technology and load control technology, a large number of power electronic equipment such as distributed renewable energy power generation and the like are connected into a 400V low-voltage distribution network to form a renewable energy micro-grid system. In order to reduce loss caused by power failure and ensure the reliability of important load power supply, the micro-grid is required to have a parallel/off-grid dual-mode operation function. In addition, with technological development and large-scale distributed power access to the power distribution network, the power flow of the power grid changes, the load structure also tends to be complicated and developed, and a large amount of capacitive load and inductive load are mainly accessed to the low-voltage power distribution network.
In the grid-connected mode, the micro-grid can basically keep the voltage and the frequency of the grid stable due to the clamping effect of the main grid, and ensure the stable operation of the load. However, when the system is in off-grid operation, the system is separated from the main power grid clamp, the system is in self-supporting load operation, the instability of power supply voltage and frequency in a micro-grid area can damage electric equipment, and particularly when the output load rate is reduced, the output frequency of the small hydropower generation system is changed due to the fact that the small hydropower generation system cannot respond to power change quickly, so that the frequency exceeds the standard when the micro-grid is off-grid, and even off-grid work can be stopped.
Disclosure of Invention
The application provides a parallel-off-grid small hydropower station response control device and method, which are used for solving the problem of unstable operation of a micro-grid.
On one hand, the application provides a parallel-off-grid small hydropower station response control method, which comprises the following steps:
initializing parameters of a small hydropower station response control device which is connected and disconnected, acquiring a ratio coefficient alpha of grid-connected point power and current small hydropower station power generation power according to station change historical monitoring data, and generating a time-power-voltage correspondence table of a year duration;
step two, monitoring the output voltage, current and frequency change of the small hydropower station in real time, and stabilizing the output frequency of the small hydropower station through supporting the frequency or voltage fluctuation of the micro-grid by the bidirectional energy storage converter;
analyzing the power increase and decrease of the small hydropower station at the off-grid moment and the power absorption or release of the bidirectional energy storage converter, and predicting the load power at the next moment according to a time-power-voltage correspondence table of one year duration:
monitoring the frequency change of the micro-grid after entering the off-grid state in real time, sending out a control command for increasing or decreasing the absorption power to the bidirectional energy storage converter according to the frequency change of the micro-grid, and simultaneously, working the small hydropower station according to a self control strategy;
and fifthly, increasing or decreasing the value range of the time-power-voltage correspondence table for one year according to the value of increasing or decreasing the absorbed power at the current moment, and iterating out the new value range of the external network synchronous power supply. Optionally, in the first step, the parameters of the parallel-off-grid small hydropower station response control device include capacity, power, quantity, maximum charge and discharge current, minimum residual electric quantity and capacity of the small hydropower station, power change rate, average power generation in a high-water season and average power generation in a dead water season of the bidirectional energy storage converter.
Optionally, in the first step, the parameters of the parallel-off-grid small hydropower station response control device include capacity, power, quantity, maximum charge and discharge current, minimum residual electric quantity and capacity of the small hydropower station, power change rate, average power generation in a high-water season and average power generation in a dead water season of the bidirectional energy storage converter.
Optionally, in the first step, the value range of the ratio coefficient α of the grid-connected point output power to the current small hydropower generation power is (0.1, 0.5).
Optionally, in the third step, the load power range (P tmin ，P tmax ) Judging and determining the tide direction:
when P tmin Not less than 0 or P tmax When the power flow direction is more than or equal to 0, the upper power grid and the small hydropower station supply power for the micro-power grid together;
when p is tmax < 0 or p tmin When the power flow direction is less than 0, the small water power is used as the micro-grid and supplies power to the external network;
wherein p is tmin Minimum power in the time-power-voltage correspondence table for a duration of one year;p tmax maximum power in the time-power-voltage correspondence table for a duration of one year:
optionally, U ugb Is the national standard upper limit voltage, U lgb Is the lower limit voltage of national standard, U ac For real-time monitoring and off-grid small hydropower station response control module outlet voltage, P sid To absorb or release power for the bidirectional energy storage converter, P wid To increase or decrease the small hydropower generation power, P tave Is the average power P tave The method comprises the steps of carrying out a first treatment on the surface of the If P tmin Not less than 0 or P tmax ≥0，
(a) When U is monitored ac ≥δ u U ugb When the load power at the next moment is defined as p tmin The method comprises the steps of carrying out a first treatment on the surface of the When (when)When the power supplied by the external network is far smaller than that supplied by the small hydropower station, the power P of the small hydropower station decreases when off-network occurs wid And the absorption power P of the bidirectional energy storage converter wid ＝P sid ＝P non -P tmin The method comprises the steps of carrying out a first treatment on the surface of the When->When the external network power supply is close to the small hydropower station power supply, the small hydropower station keeps the original power P when off-network occurs wid Outputting the released power of the bidirectional energy storage converter as P sid ＝P tmin -P non ；
(b) When U is detected ac ≤δ l U lgb When the load power at the next moment is defined as p tmax The method comprises the steps of carrying out a first treatment on the surface of the When (when)When the power supplied by the external network is far smaller than that supplied by the small hydropower station, the power of the small hydropower station decreases when off-network occurs, and the absorbed power of the bidirectional energy storage converter is P wid ＝P sid ＝P non -P tmax ；
When (when)Outer netThe power supply power is close to the power supply of the small hydropower station, and the small hydropower station keeps the original power P when off-grid occurs wid Outputting the released power of the bidirectional energy storage converter as P sid ＝P tmax -P non ；
(c) When delta is detected l U lgb ＜U ac ＜δ u U ugb At the future time, the maximum load power is defined as p tmax At least p tmin Average power
When (when)When the power supplied by the external network is far smaller than that supplied by the small hydropower station, the power of the small hydropower station decreases when off-network occurs, and the absorbed power of the bidirectional energy storage converter is P wid ＝P sid ＝P non -P tave ；
When (when)When the external network power supply is close to the small hydropower station power supply, the small hydropower station keeps the original power P when off-network occurs wid Outputting the released power of the bidirectional energy storage converter as P sid ＝P tave -P non ；
Optionally, U ugb Is the national standard upper limit voltage, U lgb Is the lower limit voltage of national standard, U ac For real-time monitoring and off-grid small hydropower station response control module outlet voltage, P sid To absorb or release power for the bidirectional energy storage converter, P wid To increase or decrease the small hydropower generation power, P tave Is the average power P tave The method comprises the steps of carrying out a first treatment on the surface of the If P tmi n < 0 or P tmax ＜0，
(a) When U is monitored ac ≥δ u U ugb When the load power at the next moment is defined as p tmin The method comprises the steps of carrying out a first treatment on the surface of the At the moment, the small hydropower station reduces power P when off-grid occurs wid And the absorption power P of the bidirectional energy storage converter sid Is P wid ＝P sid ＝P non +P tmin ；
(b) When U is detected ac ≤δ l U lgb When the load power at the next moment is defined as p tmax The method comprises the steps of carrying out a first treatment on the surface of the At the moment, when off-grid occurs, the small hydropower station reduces power and the two-way energy storage converter absorbs power to be P wid ＝P sid ＝P non +P tmax ；
(c) When delta is detected l U lgb ＜U ac ＜δ u U ugb At the future time, the maximum load power is defined as p tmax At least p tmin Average powerAt the moment, when off-grid occurs, the small hydropower station reduces power and the two-way energy storage converter absorbs power to be P wid ＝P sid ＝P non +P tave ；
Optionally, in the fourth step, the micro-grid parameters include small hydropower station power P wid And the absorption power P of the bidirectional energy storage converter sid 。
On one hand, the application provides a parallel-off-grid small hydropower station response control device which comprises a control module, a communication module, a carrier wave receiving module, a short circuit monitoring module, a voltage sensor, a current sensor, a bidirectional energy storage converter, a switch driving module and a contactor, wherein the control module is connected with the communication module;
the voltage sensor, the current sensor and the contactor are connected in series, and the bidirectional energy storage converter and the small water power supply are respectively connected with the current sensor; the current sensor is connected with the short circuit monitoring module, and the short circuit monitoring module is connected with the control module; the contactor is connected with the switch driving module, and the switch driving module is connected with the control module;
the control module is configured to collect data of the current sensor, data of the voltage sensor and a short circuit state of the short circuit monitoring module, and control the on and off of the contactor through the switch driving module;
the carrier receiving module is connected with the control module, the control module is connected with the communication module, and the bidirectional energy storage converter and the small hydropower station are connected with the communication module.
Optionally, the switch driving module includes a latch control sub-module, and the latch control end is connected with the short circuit monitoring module.
As can be seen from the above technical solution, the present application provides a parallel-off-grid small hydropower station response control device and method, the method includes generating a time-power-voltage correspondence table of a year duration according to station change history monitoring data; monitoring the change of the output voltage, current and frequency of the small hydropower station in real time, and stabilizing the output frequency of the small hydropower station; the method comprises the steps of predicting the frequency change of a micro-grid after load power in the next moment is monitored in real time by analyzing the power increase and decrease of a small hydropower station at the off-grid moment and the power absorption or release of a bidirectional energy storage converter, sending a power absorption increasing or decreasing control command to the bidirectional energy storage converter according to the frequency change of the micro-grid, and simultaneously, enabling the small hydropower station to work according to a self control strategy; and (3) increasing or decreasing the value range of the time-power-voltage correspondence table for one year according to the value of increasing or decreasing the absorption power at the current moment, and iterating out the value range of the new external network synchronous power supply power so as to ensure the safe and stable operation of the micro-grid.
Drawings
In order to more clearly illustrate the technical solution of the present application, the drawings that are needed in the embodiments will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.
FIG. 1 is a schematic diagram of a parallel-off-grid small hydropower station response control device;
FIG. 2 is a flow chart of a method for controlling response of small hydropower stations on off-grid in accordance with the present application.
Detailed Description
Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The embodiments described in the examples below do not represent all embodiments consistent with the application. Merely exemplary of systems and methods consistent with aspects of the application as set forth in the claims.
Referring to fig. 1, a schematic structural diagram of a small off-grid hydropower station response control device according to the application is shown. As can be seen from fig. 1, the parallel-off-grid small hydropower station response control device provided by the application comprises a control module, a communication module, a carrier wave receiving module, a short circuit monitoring module, a voltage sensor, a current sensor, a bidirectional energy storage converter, a switch driving module and a contactor;
the voltage sensor, the current sensor and the contactor are connected in series, and the bidirectional energy storage converter and the small water power supply are respectively connected with the current sensor; the current sensor is connected with the short circuit monitoring module, and the short circuit monitoring module is connected with the control module; the contactor is connected with the switch driving module, and the switch driving module is connected with the control module;
the control module is configured to collect data of the current sensor, data of the voltage sensor and a short circuit state of the short circuit monitoring module, and control on and off of the contactor through the switch driving module.
The control module monitors the output power and the voltage of the small hydropower station and the change of the frequency monitored by the bidirectional energy storage converter through the voltage sensor and the current sensor, analyzes and predicts the influence of the small hydropower station on the micro-grid when the small hydropower station occurs and leaves the small hydropower station at the future moment according to the historical data of the station change, and controls the bidirectional energy storage converter to quickly absorb or release the power to make the grid tend to be stable during switching.
The carrier receiving module is connected with the control module, the control module is connected with the communication module, and the bidirectional energy storage converter and the small hydropower station are connected with the communication module.
Further, the switch driving module comprises a locking control sub-module, and the locking control end is connected with the short circuit monitoring module. When the small hydropower station fails and is short-circuited, the locking control sub-module starts a locking state, rapidly cuts off the connection between the small hydropower station and the micro-grid, and locks the failure state. And after the short circuit monitoring module monitors that the fault is removed, the locking control submodule is unlocked.
Referring to fig. 2, a flow chart of a response control method of small off-grid hydropower station according to the application is shown. In a specific embodiment, the method is implemented by the control device, and the method includes:
initializing parameters of a small hydropower station response control device which is connected and disconnected, acquiring a ratio coefficient alpha of grid-connected point power and current small hydropower station power generation power according to station change historical monitoring data, and generating a time-power-voltage correspondence table of a year duration;
the parameters of the off-grid small hydropower station response control device comprise the capacity, power, quantity, maximum charge and discharge current, minimum residual capacity, small hydropower station capacity, power change rate, high-water-season average power generation and low-water-season average power generation of the bidirectional energy storage converter. The value range of the ratio coefficient alpha of the grid-connected point output power to the current small hydropower generation power is (0.1, 0.5);
the time-power-voltage correspondence table of one year duration can be formulated according to the historical detection data of the previous year, and the 15 minutes per hour is divided into 4 time periods by reading the historical detection data of the previous year, and the tide direction in each time period, namely u, is analyzed t1 A 1 st minute voltage that is a 15 th minute period of historical synchronization; u (u) t2 2 nd minute voltage for 15 th minute period of history synchronization; u (u) t15 15 th minute voltage, which is a 15 th minute period of historical synchronization; p is p t1 1 st minute power for 15 minute period of history synchronization; p is p t2 2 nd minute power for 15 th minute period of history synchronization; p is p t15 15 th minute power for 15 th minute period of historical synchronization;
respectively finding out the historic contemporaneous maximum power value P by taking 15 minutes as a period tmax ＝max(P t1 ，P t2 ，…P t15 ) And a minimum power value P tmin ＝min(P t1 ，P t2 ，...P t15 ) The method comprises the steps of carrying out a first treatment on the surface of the Voltage maximumLow value U tmin ＝min(u t1 ，u t2 ，...u t15 ) Sum voltage maximum U tmax ＝max(u t1 ，u t2 ，...u t15 )；
The power value of the station transformer historical monitoring data is positive to supply power to the micro-grid for the external network, and conversely, the power value of the station transformer historical monitoring data is negative to supply power to the micro-grid for the small hydropower station; p (P) tmax Maximum power within 15 minutes of the history synchronization; p (P) tmin Minimum power within 15 minutes of the history synchronization; u (U) tmin Minimum voltage within 15 minutes period for the contemporaneous history; u (U) tmax Maximum voltage within 15 minutes period for historical synchronization; at the same time find the maximum power P tmax Corresponding voltage U t_max Value, minimum power P tmin Corresponding voltage U t_min A value; u (u) t1 Average voltage at 1 st minute for 15 min period of history synchronization; u (u) t2 Average voltage at 2 nd minute for 15 min period of history synchronization; u (u) t15 15 th minute average voltage for 15 th minute period of historical synchronization; p is p t1 Average power at 1 st minute for 15 min period of historical synchronization; p is p t2 Average power at 2 nd minute for 15 min period of historical synchronization; p is p t15 15 th minute average power for 15 th minute period of historical synchronization; i.e max Maximum current in 15 minutes period for historical synchronization; thus, a time-power-voltage correspondence table of one-year duration of the history monitoring data of the station change is correspondingly generated.
Step two, monitoring the output voltage, current and frequency change of the small hydropower station in real time, and stabilizing the output frequency of the small hydropower station through supporting the frequency or voltage fluctuation of the micro-grid by the bidirectional energy storage converter;
further, certain energy storage electric quantity is ensured when the small hydropower station supplies power, the rapid support of the power grid in fluctuation can be met, the power is absorbed when the frequency is increased, and the power is released when the frequency is reduced, so that the small hydropower station output frequency is stabilized. Because the support response time of the bidirectional energy storage converter is in the second level, the required energy storage capacity is smaller, and the bidirectional energy storage converter is determined according to the small hydropower generation capacity and the maximum adjustment range. For example, when the power generation capacity of small hydropower is 3MW and the power is reduced or increased by 10%, 7 seconds are needed, 10 seconds are taken as 1/6 hour, the energy storage capacity is 3MW 10% 1/6=50 kWh, and the energy storage capacity is small.
Analyzing the power increase and decrease of the small hydropower station at the off-grid moment and the power absorption or release of the bidirectional energy storage converter, and predicting the load power at the next moment according to a time-power-voltage correspondence table of one year duration:
by the range of the load power value (P tmin ，P tmax ) Judging and determining the tide direction:
when P tmin Not less than 0 or P tmax When the power flow direction is more than or equal to 0, the upper power grid and the small hydropower station supply power for the micro-power grid together;
when p is tmax < 0 or p tmin When the power flow direction is less than 0, the small water power is used as the micro-grid and supplies power to the external network;
wherein p is tmin Minimum load power for future time; p is p tmax U is the maximum power at the future time ugb Is the national standard upper limit voltage, U lgb Is the lower limit voltage of national standard, U ac For real-time monitoring and off-grid small hydropower station response control module outlet voltage, P sid To absorb or release power for the bidirectional energy storage converter, P wid To increase or decrease the small hydropower generation power, P tave Is the average power P tave 。
If P tmin Not less than 0 or P tmax ≥0，
(a) When U is monitored ac ≥δ u U ugb When the load power at the next moment is defined as p tmin The method comprises the steps of carrying out a first treatment on the surface of the When (when)When the power supplied by the external network is far smaller than that supplied by the small hydropower station, the power P of the small hydropower station decreases when off-network occurs wid And the absorption power P of the bidirectional energy storage converter sid Is P wid ＝P sid ＝P non -P tmin The method comprises the steps of carrying out a first treatment on the surface of the When->When the external network power supply is close to the small hydropower station power supply, the small hydropower station keeps the original power P when off-network occurs wid Outputting the released power of the bidirectional energy storage converter as P sid ＝P tmin -P non ；
(b) When U is detected ac ≤δ l U lgb When the load power at the next moment is defined as p tmax The method comprises the steps of carrying out a first treatment on the surface of the When (when)When the power supplied by the external network is far smaller than that supplied by the small hydropower station, the power of the small hydropower station decreases when off-network occurs, and the absorbed power of the bidirectional energy storage converter is P wid ＝P sid ＝Pnon-P tmax ；
When (when)When the external network power supply is close to the small hydropower station power supply, the small hydropower station keeps the original power P when off-network occurs wid Outputting the released power of the bidirectional energy storage converter as P sid ＝P tmax -P non ；
(c) When delta is detected l U lgb ＜U ac ＜δ u U ugb At the future time, the maximum load power is defined as p tmax At least p tmin Average power
When (when)When the power supplied by the external network is far smaller than that supplied by the small hydropower station, the power of the small hydropower station decreases when off-network occurs, and the absorbed power of the bidirectional energy storage converter is P wid ＝P sid ＝P non -P tave ；
When (when)When the external network power supply is close to the small hydropower station power supply, the small hydropower station keeps the original power P when off-network occurs wid Outputting the released power of the bidirectional energy storage converter as P sid ＝P tave -P non ；
If P tmin < 0 or P tmax ＜0，
(a) When U is monitored ac ≥δ u U ugb When the load power at the next moment is defined as p tmin The method comprises the steps of carrying out a first treatment on the surface of the At the moment, the small hydropower station reduces power P when off-grid occurs wid And the absorption power P of the bidirectional energy storage converter sid Is P wid ＝P sid ＝P non +P tmin ；
(b) When U is detected ac ≤δ l U lgb When the load power at the next moment is defined as p tmax The method comprises the steps of carrying out a first treatment on the surface of the At the moment, when off-grid occurs, the small hydropower station reduces power and the two-way energy storage converter absorbs power to be P wid ＝P sid ＝P non +P tmax ；
(c) When delta is detected l U lgb ＜U ac ＜δ u U ugb At the future time, the maximum load power is defined as p tmax At least p tmin Average powerAt the moment, when off-grid occurs, the small hydropower station reduces power and the two-way energy storage converter absorbs power to be P wid ＝P sid ＝P non +P tave ；
Thereby, by establishing as small hydropower increase and decrease power P wid And the bidirectional energy storage converter absorbs or releases power P sid And the control module sends out predictive analysis protocol codes to the small hydropower station and the bidirectional energy storage converter respectively through the communication module according to analysis results when off-grid operation occurs, so that the micro-grid is quickly adapted to grid change at off-grid moment, and the frequency violent change caused by small hydropower station power generation inertia due to power change is avoided.
Monitoring the frequency change of the micro-grid after entering the off-grid state in real time, sending out a control command for increasing or decreasing the absorption power to the bidirectional energy storage converter according to the frequency change of the micro-grid, and simultaneously, working the small hydropower station according to a self control strategy;
when the frequency of the micro-grid is monitored to be increased, the control module sends out increased absorption power P to the bidirectional energy storage converter sid +ΔP sid Control commands of (2);
when the micro-grid frequency is monitored to be reduced, the control module sends out reduced absorption power P to the bidirectional energy storage converter sid -ΔP sid Control commands of (2);
wherein DeltaP sid For micro-grid frequency to approach 50Hz + -Deltaf HZ The absorption power value of the bidirectional energy storage converter is increased or decreased on the basis of the absorption power of the predictive analysis protocol code;
further, the Δf HZ According to the frequency level: the A level is less than or equal to +/-0.05 Hz, the B level is less than or equal to +/-0.5 Hz, and the C level is less than or equal to +/-1 Hz.
And fifthly, increasing or decreasing the value range of the time-power-voltage correspondence table for one year according to the value of increasing or decreasing the absorbed power at the current moment, and iterating out the new value range of the external network synchronous power supply.
Further, at the grid-connected time, as the external grid participates in power supply, the small hydropower station gradually increases power with the aim of maximizing power output, and meanwhile, the residual electric quantity of the bidirectional energy storage converter is optimized.
While the fundamental and principal features of the application and advantages of the application have been shown and described, it will be apparent to those skilled in the art that the application is not limited to the details of the foregoing exemplary embodiments, but may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Furthermore, it should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is provided for clarity only, and that the disclosure is not limited to the embodiments described in detail below, and that the embodiments described in the examples may be combined as appropriate to form other embodiments that will be apparent to those skilled in the art.
The above-provided detailed description is merely a few examples under the general inventive concept and does not limit the scope of the present application. Any other embodiments which are extended according to the solution of the application without inventive effort fall within the scope of protection of the application for a person skilled in the art.

Claims (7)

1. The parallel-off-grid small hydropower station response control method is characterized by comprising the following steps of:
initializing parameters of a small hydropower station response control device which is connected and disconnected, acquiring a ratio coefficient alpha of grid-connected point power and current small hydropower station power generation power according to station change historical monitoring data, and generating a time-power-voltage correspondence table of a year duration;
step two, monitoring the output voltage, current and frequency change of the small hydropower station in real time, and stabilizing the output frequency of the small hydropower station through supporting the frequency or voltage fluctuation of the micro-grid by the bidirectional energy storage converter;
analyzing the power increase and decrease of the small hydropower station at the off-grid moment and the power absorption or release of the bidirectional energy storage converter, and predicting the load power at the next moment according to a time-power-voltage correspondence table of one year duration:
monitoring the frequency change of the micro-grid after entering the off-grid state in real time, sending out a control command for increasing or decreasing the absorption power to the bidirectional energy storage converter according to the frequency change of the micro-grid, and simultaneously, working the small hydropower station according to a self control strategy;
fifthly, increasing or decreasing the value range of the time-power-voltage correspondence table for one year duration according to the value of increasing or decreasing the absorption power at the current moment, and iterating out a new value range of the external network synchronous power supply;
in the third step, the value range (P tmin ,P tmax ) Judging and determining the tide direction:
when P tmin Not less than 0 or P tmax When the power flow direction is more than or equal to 0, the upper power grid and the small hydropower station supply power for the micro-power grid together;
when p is tmax <0 or p tmin <When 0, the tide direction is that the small hydropower is the micro-grid and supplies power to the external network;
wherein p is tmin Minimum power in the time-power-voltage correspondence table for a duration of one year; p is p tmax Maximum power in the time-power-voltage correspondence table for a duration of one year;
U ugb is the national standard upper limit voltage, U lgb Is the lower limit voltage of national standard, U ac For real-time monitoring and off-grid small hydropower station response control module outlet voltage, P sid Absorbing or releasing power for a bi-directional energy storage converter, p wid To increase or decrease the small hydropower generation power, P tave Is the average power P tave The method comprises the steps of carrying out a first treatment on the surface of the If P tmin Not less than 0 or P tmax ≥0，
(a) When U is monitored ac ≥δ u U ugb When the load power at the next moment is defined as p tmin The method comprises the steps of carrying out a first treatment on the surface of the When (when)When the power supplied by the external network is far smaller than that supplied by the small hydropower station, the power P of the small hydropower station decreases when off-network occurs wid And the absorption power P of the bidirectional energy storage converter wid ＝P sid ＝P non -P tmin The method comprises the steps of carrying out a first treatment on the surface of the When->When the external network power supply is close to the small hydropower station power supply, the small hydropower station keeps the original power p when off-network occurs wid Outputting the released power of the bidirectional energy storage converter as P sid ＝P tmin -P non ；
(b) When U is detected ac ≤δ l U lgb When the load power at the next moment is defined as p tmax The method comprises the steps of carrying out a first treatment on the surface of the When (when)When the power supplied by the external network is far smaller than that supplied by the small hydropower station, the power of the small hydropower station decreases when off-network occurs, and the absorbed power of the bidirectional energy storage converter is P wid ＝P sid ＝P non -p tmax ；
When (when)When the external network power supply is close to the small hydropower station power supply, the small hydropower station keeps the original power P when off-network occurs wid Outputting the released power of the bidirectional energy storage converter as P sid ＝p tmax -P non ；
(c) When delta is detected l U lgb <U ac <δ u U ugb At the future time, the maximum load power is defined as p tmax At least p tmin Average power
When (when)When the power supplied by the external network is far smaller than that supplied by the small hydropower station, the power of the small hydropower station decreases when off-network occurs, and the absorbed power of the bidirectional energy storage converter is P wid ＝P sid ＝P non -P tave ；
When (when)When the external network power supply is close to the small hydropower station power supply, the small hydropower station keeps the original power P when off-network occurs wid Outputting the released power of the bidirectional energy storage converter as P sid ＝P tave -P non 。
2. The method for controlling response of small parallel and off-grid hydropower stations according to claim 1, wherein in the first step, parameters of the small parallel and off-grid hydropower stations response control device include capacity, power, quantity, maximum charge and discharge current, minimum residual capacity, small hydropower station capacity, power change rate, average power generation in a high-water season and average power generation in a low-water season of the bidirectional energy storage converter.
3. The method for controlling response of small hydropower stations on a parallel/off network according to claim 1, wherein in the first step, the ratio coefficient α of the output power of the grid-connected point to the current small hydropower station power is in the range of (0.1, 0.5).
4. The parallel-off-grid small hydropower station response control method according to claim 1, wherein U is as follows ugb Is the national standard upper limit voltage, U lgb Is the lower limit voltage of national standard, U ac For real-time monitoring and off-grid small hydropower station response control module outlet voltage, P sid To absorb or release power for the bidirectional energy storage converter, P wid To increase or decrease the small hydropower generation power, P tave Is the average power P tave The method comprises the steps of carrying out a first treatment on the surface of the If p tmin <0 or P tmax <0，
(a) When U is monitored ac ≥δ u U ugb When the load power at the next moment is defined as p tmin The method comprises the steps of carrying out a first treatment on the surface of the At the moment, the small hydropower station reduces power P when off-grid occurs wid And the absorption power P of the bidirectional energy storage converter sid Is P wid ＝P sid ＝P non +P tmin ；
(b) When U is detected ac ≤δ l U lgb When the load power at the next moment is defined as p tmax The method comprises the steps of carrying out a first treatment on the surface of the At the moment, when off-grid occurs, the small hydropower station reduces power and the two-way energy storage converter absorbs power to be P wid ＝P sid ＝P non +P tmax ；
(c) When delta is detected l U lgb <U ac <δ u U ugb At the future time, the maximum load power is defined as p tmax At least p tmin Average powerAt the moment, when off-grid occurs, the small hydropower station reduces power and the two-way energy storage converter absorbs power to be P wid ＝P sid ＝P non +P tave 。
5. The parallel-off-grid small hydropower station response control method according to claim 1, wherein in the fourth step, the micro-grid parameters comprise small hydropower station power reduction P wid And the absorption power P of the bidirectional energy storage converter sid 。
6. The parallel-to-off-grid small hydropower station response control device is applied to the parallel-to-off-grid small hydropower station response control method according to claim 1 and is characterized by comprising a control module, a communication module, a carrier receiving module, a short circuit monitoring module, a voltage sensor, a current sensor, a bidirectional energy storage converter, a switch driving module and a contactor;
the voltage sensor, the current sensor and the contactor are connected in series, and the bidirectional energy storage converter and the small water power supply are respectively connected with the current sensor; the current sensor is connected with the short circuit monitoring module, and the short circuit monitoring module is connected with the control module; the contactor is connected with the switch driving module, and the switch driving module is connected with the control module;
the control module is configured to collect data of the current sensor, data of the voltage sensor and a short circuit state of the short circuit monitoring module, and control the on and off of the contactor through the switch driving module;
the carrier receiving module is connected with the control module, the control module is connected with the communication module, and the bidirectional energy storage converter and the small hydropower station are connected with the communication module.
7. The parallel off-grid small hydropower response control device according to claim 6, wherein the switch driving module comprises a locking control sub-module, and the locking control sub-module is connected with the short circuit monitoring module.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104362665A (en) * 2014-09-28 2015-02-18 北京索英电气技术有限公司 Microgrid on-grid to off-grid switching control system and control method thereof
CN107508303A (en) * 2017-08-09 2017-12-22 国电南瑞科技股份有限公司 A kind of modularization energy storage device towards micro-capacitance sensor is distributed rationally and control method
CN111987723A (en) * 2020-09-01 2020-11-24 云南电网有限责任公司电力科学研究院 Micro-grid operation control method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104362665A (en) * 2014-09-28 2015-02-18 北京索英电气技术有限公司 Microgrid on-grid to off-grid switching control system and control method thereof
CN107508303A (en) * 2017-08-09 2017-12-22 国电南瑞科技股份有限公司 A kind of modularization energy storage device towards micro-capacitance sensor is distributed rationally and control method
CN111987723A (en) * 2020-09-01 2020-11-24 云南电网有限责任公司电力科学研究院 Micro-grid operation control method

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
光储微电网联络线功率控制策略的仿真研究;王;陶琼;杨海晶;李朝晖;;低压电器(第14期);全文 *

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