Active power integrated closed-loop control circuit and system for photovoltaic power station

Abstract

The utility model discloses an active power integrated closed-loop control circuit and system for a photovoltaic power station, and relates to the technical field of photovoltaic power generation. A photovoltaic power station scheduling active power instruction and inverter state information are processed in a system input circuit; the power deviation control circuit module selects different control modes according to deviation between instructions and actual sending of a photovoltaic field station, and the inverter dispatching control circuit module distributes the instructions according to the operation state and capacity of an inverter in an equal proportion mode. The closed-loop control of the photovoltaic station can improve the control precision of the photovoltaic station, so that the photovoltaic station can better track a scheduling instruction. Through the improvement of the control circuit, the response speed of the photovoltaic station can be improved, the overshoot of the photovoltaic station is reduced, and the photovoltaic station can track a scheduling instruction more quickly.

Description

Technical Field

[0001] The utility model discloses an active power integrated closed-loop control circuit and system for a photovoltaic power station, and relates to the technical field of photovoltaic power generation. Background Art

[0002] Traditional distributed PV power plants only consider the operational status of the PV inverters, employing open-loop control based on this status. This approach fails to account for faulty PV panels within individual PV arrays. After receiving the active power command from the dispatch / AGC coordination controller, it directly distributes the active power command based on the installed capacity of each inverter. This makes it difficult to accurately track the active power command value when a faulty inverter is present, leading to a discrepancy between the command and actual power output of the PV power plant. This discrepancy increases with the maximum power output of the PV plant.

[0003] Traditional closed-loop control circuits often use deviation-based proportional or proportional-integral control. Because pure proportional control cannot achieve zero-error regulation, an integral component is necessary. However, using proportional-integral control can lead to integral saturation due to the cycle and step size of photovoltaic power station commands, causing system overshoot and increasing system settling time.

[0004] Therefore, an integrated closed-loop control circuit for active power of a photovoltaic power station is invented to solve the above problems. Utility Model Content

[0005] In response to the problems of the prior art, the present invention provides an integrated closed-loop control circuit for active power of a photovoltaic power station. The technical solution adopted is:

[0006] In a first aspect, an active power integrated closed-loop control circuit for a photovoltaic power station, the control circuit comprising an input circuit, a power deviation control circuit, and a dispatch control circuit;

[0007] The input circuit includes an input subcircuit module, a processing subcircuit and an output subcircuit, and the input subcircuit is connected to the output subcircuit through the processing subcircuit;

[0008] Wherein, the processing sub-circuit includes transistor Q1, transistor Q2, resistor R2, resistor R3 and capacitor C2;

[0009] The bases of the transistors Q1 and Q2 are connected, the collectors of the transistors Q1 and Q2 are connected to the resistor R2 and the capacitor C2 respectively, and the capacitor C3 is connected to the resistor R3;

[0010] The power deviation control circuit includes a deviation calculation subcircuit, a dead zone judgment subcircuit, a dead zone range judgment subcircuit and a strategy execution subcircuit; the deviation calculation subcircuit is connected to the range judgment subcircuit via the dead zone range judgment subcircuit, and the dead zone range judgment subcircuit and the range judgment subcircuit are connected to the Vout signal terminal via the strategy execution subcircuit;

[0011] The dispatching control circuit includes an inverter state monitoring circuit, a signal generator subcircuit, a dead zone range judgment subcircuit, an instruction issuing and executing subcircuit and a filtering circuit;

[0012] The signal generator subcircuit is connected to the instruction issuing execution subcircuit via the dead zone range judgment subcircuit, and the dead zone range judgment subcircuit is connected to the filter circuit via the inverter state monitoring circuit.

[0013] In some implementations, the input subcircuit includes a crystal oscillator Y1, a capacitor C1, and a resistor R1;

[0014] Wherein, the crystal oscillator Y1 is connected to the resistor R1 via the capacitor C1;

[0015] The input sub-circuit and the processing sub-circuit are connected via a capacitor C1 and a transistor Q1.

[0016] In some implementations, the output subcircuit includes an operational amplifier, a resistor R4, and a resistor R5;

[0017] The opposite input terminal of the operational amplifier is connected to the capacitor R3 via the capacitor R5, and the same input terminal of the operational amplifier is connected to the capacitor C3 and the resistor R5 at the same time; the output terminal of the operational amplifier is connected to the resistor R5 via the resistor R4.

[0018] In some implementations, the dead zone determination subcircuit includes a comparator OP1, a comparator OP4, and resistors R4, R5, R6, and R7;

[0019] The input terminal and the opposite output terminal of the comparator OP4 are connected via a resistor R7; the opposite output terminal of the comparator OP4 is grounded via a resistor R6;

[0020] The deviation calculation subcircuit and the strategy execution subcircuit are connected via a comparator OP1; the range determination subcircuit and the strategy execution subcircuit are connected via a comparator OP4;

[0021] The same input terminal of the comparator OP4 is connected to the range determination sub-circuit through the resistor R4 and the resistor R5 respectively.

[0022] In some implementations, the signal generator subcircuit includes a digital FM signal generator U0, a capacitor C1, a capacitor C2, a resistor R1, and a sliding resistor POT2;

[0023] Pin 1 and pin 10 of the digital FM signal generator U0 are connected via capacitor C1 and sliding resistor POT2, and pin 2 of the digital FM signal generator U0 is connected to sliding resistor POT2;

[0024] Pin 19 of the signal generator subcircuit sends an instruction to the execution subcircuit through the dead zone range judgment subcircuit connection instruction.

[0025] In some implementations, the instruction issuing and executing sub-circuit includes a signal transmission unit U5 , and the dead zone range determination sub-circuit and the instruction issuing and executing sub-circuit are connected via the signal transmission unit U5 .

[0026] In some implementations, the digital FM signal generator U0 is implemented by AD630AD.

[0027] In some implementations, the signal transmission unit U5 is implemented by an AD630AD chip.

[0028] In a second aspect, an active power integrated closed-loop control system for a photovoltaic power station is provided. According to the circuit of the first aspect, the system is used to execute the functional structure of the circuit.

[0029] One or more embodiments of the present invention can at least bring about the following beneficial effects: the present circuit processes the active power instructions and inverter status information of the photovoltaic power station in the system input circuit; then, the power deviation control circuit module selects different control methods according to the deviation between the instructions and the actual output of the photovoltaic station; finally, the inverter scheduling control circuit module distributes the instructions in proportion to the inverter operating status and capacity. The closed-loop control of the photovoltaic station can improve the control accuracy of the photovoltaic station, allowing the photovoltaic station to better track the scheduling instructions. By improving the control circuit, the response speed of the photovoltaic station can be improved, and the overshoot of the photovoltaic station can be reduced, allowing the photovoltaic station to track the scheduling instructions more quickly. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0031] Figure 1This is a control block diagram of an active power integrated closed-loop control circuit for a photovoltaic power station provided by an embodiment of the utility model;

[0032] Figure 2 This is a structural diagram of the input circuit of the control circuit module provided by an embodiment of the present utility model;

[0033] Figure 3 It is a structural diagram of a power deviation control circuit provided by an embodiment of the utility model;

[0034] Figure 4 It is a structural diagram of the scheduling control circuit provided by an embodiment of the present utility model. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The components of the embodiments of the present invention generally described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the utility model for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0036] Example 1:

[0037] Figure 1 A control block diagram of an integrated closed-loop control circuit for active power of a photovoltaic power station is shown. The integrated closed-loop control circuit for active power of a photovoltaic power station provided in this embodiment includes:

[0038] An active power integrated closed-loop control circuit for a photovoltaic power station, the control circuit comprising an input circuit, a power deviation control circuit and a dispatching control circuit;

[0039] like Figure 2 As shown, the input circuit includes an input subcircuit module, a processing subcircuit and an output subcircuit, and the input subcircuit is connected to the output subcircuit through the processing subcircuit;

[0040] The processing subcircuit includes transistors Q1, Q2, resistors R2, R3, and capacitor C2; including fuses, filters, etc. to ensure the stability and safety of the input signal. Resistors, capacitors, and other components are used to adjust the amplitude, frequency, and other characteristics of the signal;

[0041] The bases of the transistors Q1 and Q2 are connected, the collectors of the transistors Q1 and Q2 are connected to the resistor R2 and the capacitor C2 respectively, and the capacitor C3 is connected to the resistor R3; the input signal is amplified, filtered, and shaped.

[0042] The dead zone judgment sub-circuit includes a comparator OP1, a comparator OP4 and resistors R4, R5, R6 and R7;

[0043] The input terminal and the opposite output terminal of the comparator OP4 are connected via a resistor R7; the opposite output terminal of the comparator OP4 is grounded via a resistor R6;

[0044] The deviation calculation subcircuit and the strategy execution subcircuit are connected via a comparator OP1; the range determination subcircuit and the strategy execution subcircuit are connected via a comparator OP4;

[0045] The same input terminal of the comparator OP4 is connected to the range determination sub-circuit through the resistor R4 and the resistor R5 respectively.

[0046] The power deviation control circuit includes a deviation calculation subcircuit, a dead zone judgment subcircuit, a dead zone range judgment subcircuit and a strategy execution subcircuit, which collects the command power and actual power generation of the photovoltaic station in real time; the data acquisition unit of the deviation calculation subcircuit is used to collect the command power and actual power generation of the photovoltaic station; the subtractor is used to calculate the deviation between the command power and the actual power; the deviation between the two is calculated and the deviation value is passed to the subsequent dead zone judgment subcircuit.

[0047] The deviation calculation subcircuit includes a comparator (for comparing the deviation value with the dead zone threshold); a logic control unit (for controlling the reset of the integral and the execution of subsequent processes); and a circuit for receiving the deviation value transmitted by the power deviation calculation submodule. The circuit determines whether the deviation value is within the dead zone. If the deviation is within the dead zone, subsequent control strategies are discontinued and the integral is reset. If the deviation is outside the dead zone, the deviation value is passed to the subsequent range determination submodule.

[0048] The region judgment subcircuit includes a comparator (for comparing the deviation value with the dead zone threshold), a logic control unit (for controlling the integral clearing and the execution of subsequent processes), and is used to receive the deviation value transmitted by the power deviation calculation submodule and determine whether the deviation value is within the dead zone range.

[0049] If the deviation is within the dead zone, the subsequent control strategy will not be executed and the integral will be cleared to zero.

[0050] If the deviation is outside the dead zone, the deviation value is passed to the subsequent range judgment submodule.

[0051] Specifically, the deviation calculation subcircuit is connected to the range determination subcircuit via the dead zone range determination subcircuit, and the dead zone range determination subcircuit and the range determination subcircuit are connected to the Vout signal terminal via the strategy execution subcircuit.

[0052] The dispatching control circuit includes an inverter state monitoring circuit, a signal generator subcircuit, a dead zone range judgment subcircuit, an instruction issuing and executing subcircuit and a filtering circuit;

[0053] The signal generator subcircuit is connected to the instruction issuing execution subcircuit via the dead zone range judgment subcircuit, and the dead zone range judgment subcircuit is connected to the filter circuit via the inverter state monitoring circuit.

[0054] Capacitors in the instruction-issuing executor circuit provide filtering and stabilization in the control signal generation and transmission units. Resistors limit current and protect other components in the circuit. The signal transmission unit, which includes components such as the AD630AD chip, isolates and transmits control signals to the inverter, ensuring signal integrity and security.

[0055] Specifically, the input subcircuit includes a crystal oscillator Y1, a capacitor C1 and a resistor R1;

[0056] Wherein, the crystal oscillator Y1 is connected to the resistor R1 via the capacitor C1;

[0057] The input sub-circuit and the processing sub-circuit are connected via a capacitor C1 and a transistor Q1.

[0058] In some implementations, the output subcircuit includes an operational amplifier, a resistor R4, and a resistor R5;

[0059] The opposite input terminal of the operational amplifier is connected to the capacitor R3 via the capacitor R5, and the same input terminal of the operational amplifier is connected to the capacitor C3 and the resistor R5 at the same time; the output terminal of the operational amplifier is connected to the resistor R5 via the resistor R4.

[0060] Specifically, the dead zone judgment sub-circuit includes a comparator OP1, a comparator OP4 and resistors R4, R5, R6 and R7;

[0061] The input terminal and the opposite output terminal of the comparator OP4 are connected via a resistor R7; the opposite output terminal of the comparator OP4 is grounded via a resistor R6;

[0062] The deviation calculation subcircuit and the strategy execution subcircuit are connected via a comparator OP1; the range determination subcircuit and the strategy execution subcircuit are connected via a comparator OP4;

[0063] The same input terminal of the comparator OP4 is connected to the range determination sub-circuit through the resistor R4 and the resistor R5 respectively.

[0064] In some implementations, the signal generator subcircuit includes a digital FM signal generator U0, a capacitor C1, a capacitor C2, a resistor R1, and a sliding resistor POT2;

[0065] Pin 1 and pin 10 of the digital FM signal generator U0 are connected via capacitor C1 and sliding resistor POT2, and pin 2 of the digital FM signal generator U0 is connected to sliding resistor POT2;

[0066] Pin 19 of the signal generator subcircuit sends an instruction to the execution subcircuit through the dead zone range judgment subcircuit connection instruction.

[0067] In some implementations, the instruction issuing and executing sub-circuit includes a signal transmission unit U5 , and the dead zone range determination sub-circuit and the instruction issuing and executing sub-circuit are connected via the signal transmission unit U5 .

[0068] Specifically, the digital FM signal generator U0 is implemented by AD630AD.

[0069] Specifically, the signal transmission unit U5 is implemented by an AD630AD chip.

[0070] Example 2:

[0071] Based on the first embodiment, this embodiment provides an active power integrated closed-loop control system for a photovoltaic power station, which is used to execute the functional structure of the circuit.

[0072] The active power integrated closed-loop control system for a photovoltaic power station provided in this embodiment includes:

[0073] Input circuit module, power deviation control circuit module and inverter scheduling control circuit module,

[0074] The input circuit module is connected to the photovoltaic power station and the inverter respectively, and is used to obtain the active power instruction of the photovoltaic power station and the inverter status information; the active power instruction of the photovoltaic power station is rate-limited and the dead zone is judged and processed to obtain the final executed active power instruction;

[0075] The power deviation control circuit module is connected to the input circuit module and is used to select a corresponding control mode according to the deviation between the active power instruction and the actual power output of the photovoltaic power station;

[0076] The inverter scheduling control circuit module is connected to the power deviation control circuit module and the inverter respectively, and is used to distribute the active power instructions of the photovoltaic power station in proportion according to the operating status and capacity of the inverter.

[0077] Specifically, the system further includes a prediction circuit module,

[0078] The prediction circuit module is connected to the input circuit module, and is used to calculate the total active power generated by the photovoltaic station through the output of each inverter and estimate the maximum active power that can be generated by the photovoltaic station.

[0079] Specifically, when the deviation is within the dead zone, the power deviation control circuit is used to stop executing the scheduling active power instruction and clear the integral;

[0080] When the deviation is outside the dead zone, the power deviation control circuit is used to judge the deviation range and select proportional control according to the deviation size.

[0081] Specifically, the inverter scheduling control circuit module is used to determine whether each inverter instruction is within the dead zone. If it is within the dead zone, the instruction is not issued; if it is outside the dead zone, the instruction is issued for execution.

[0082] Specifically, the system also includes an AGC coordination controller, which is connected to the inverter scheduling control circuit module and is used to set the photovoltaic power station adjustment dead zone. The AGC coordination controller outputs the active power instruction of the photovoltaic power station executed at the previous moment; and distributes the instructions proportionally according to the operating status information and installed capacity of each inverter in the photovoltaic station.

[0083] During operation, the new system first receives active power dispatch commands from the PV power station and inverter status information. The system's input circuit module processes these commands using rate limits and dead-zone analysis to generate the final dispatch active power command. The total active power generated by the PV station is calculated based on the output of each inverter, estimating the station's maximum possible active power.

[0084] Then, in the power deviation control circuit module, the deviation between the instruction and actual output of the photovoltaic station is calculated to determine whether the deviation is within the dead zone. If it is within the dead zone, the execution will not continue and the integral will be cleared. If it is outside the dead zone, the deviation range will be determined and proportional control will be selected according to the deviation size.

[0085] Among them, in order to prevent the controller from frequent operation, after obtaining the photovoltaic power station command, the command set value dead zone and deviation dead zone are set;

[0086] At the same time, in order to prevent the excessive integration caused by the instruction cycle and step size, which will cause large overshoot and increase the adjustment time, the switch between pure proportional control and proportional integral control is set. Pure proportional control is used when the deviation is large, and proportional integral control is used when the deviation is small:

[0087] Finally, the inverter dispatch control circuit module distributes commands based on the operating status of each inverter. It determines whether the command deviation of each inverter is within the dead zone. If so, the command is not issued. If not, the command is issued and executed.

[0088] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. An active power integrated closed-loop control circuit for a photovoltaic power station, characterized in that: The control circuit includes an input circuit, a power deviation control circuit and a scheduling control circuit; The input circuit includes an input subcircuit module, a processing subcircuit and an output subcircuit, and the input subcircuit is connected to the output subcircuit through the processing subcircuit; Wherein, the processing sub-circuit includes transistor Q1, transistor Q2, resistor R2, resistor R3 and capacitor C2; The bases of the transistors Q1 and Q2 are connected, the collectors of the transistors Q1 and Q2 are connected to the resistor R2 and the capacitor C2 respectively, and the capacitor C3 is connected to the resistor R3; The power deviation control circuit includes a deviation calculation subcircuit, a dead zone judgment subcircuit, a dead zone range judgment subcircuit and a strategy execution subcircuit; the deviation calculation subcircuit is connected to the range judgment subcircuit via the dead zone range judgment subcircuit, and the dead zone range judgment subcircuit and the range judgment subcircuit are connected to the Vout signal terminal via the strategy execution subcircuit; The dispatching control circuit includes an inverter state monitoring circuit, a signal generator subcircuit, a dead zone range judgment subcircuit, an instruction issuing and executing subcircuit and a filtering circuit; The signal generator subcircuit is connected to the instruction issuing execution subcircuit via the dead zone range judgment subcircuit, and the dead zone range judgment subcircuit is connected to the filter circuit via the inverter state monitoring circuit.

2. The circuit according to claim 1, wherein: The input subcircuit includes a crystal oscillator Y1, a capacitor C1 and a resistor R1; Wherein, the crystal oscillator Y1 is connected to the resistor R1 via the capacitor C1; The input sub-circuit and the processing sub-circuit are connected via a capacitor C1 and a transistor Q1.

3. The circuit according to claim 1, wherein: The output sub-circuit includes an operational amplifier, a resistor R4 and a resistor R5; The opposite input terminal of the operational amplifier is connected to the capacitor R3 via the capacitor R5, and the same input terminal of the operational amplifier is connected to the capacitor C3 and the resistor R5 at the same time; the output terminal of the operational amplifier is connected to the resistor R5 via the resistor R4.

4. The circuit according to claim 1, wherein: The dead zone judgment subcircuit includes a comparator OP1, a comparator OP4 and resistors R4, R5, R6 and R7; The input terminal and the opposite output terminal of the comparator OP4 are connected via a resistor R7; the opposite output terminal of the comparator OP4 is grounded via a resistor R6; The deviation calculation subcircuit and the strategy execution subcircuit are connected via a comparator OP1; the range determination subcircuit and the strategy execution subcircuit are connected via a comparator OP4; The same input terminal of the comparator OP4 is connected to the range determination sub-circuit through the resistor R4 and the resistor R5 respectively.

5. The circuit according to claim 1, wherein: The signal generator subcircuit includes a digital FM signal generator U0, a capacitor C1, a capacitor C2, a resistor R1 and a sliding resistor POT2; Pin 1 and pin 10 of the digital FM signal generator U0 are connected via capacitor C1 and sliding resistor POT2, and pin 2 of the digital FM signal generator U0 is connected to sliding resistor POT2; Pin 19 of the signal generator subcircuit sends an instruction to the execution subcircuit through the dead zone range judgment subcircuit connection instruction.

6. The circuit according to claim 1, wherein: The instruction issuing and executing sub-circuit includes a signal transmission unit U5 , and the dead zone range determination sub-circuit and the instruction issuing and executing sub-circuit are connected via the signal transmission unit U5 .

7. The circuit according to claim 5, characterized in that The digital FM signal generator U0 is implemented by AD630AD.

8. The circuit according to claim 6, characterized in that The signal transmission unit U5 is implemented by the AD630AD chip.

9. An integrated closed-loop control system for active power in a photovoltaic power station, the circuit according to claim 1, characterized in that: The system is used to implement the functional structure of the circuit.

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