State of charge aware frequency-power coordinated control method for optical storage ac coupling system

Abstract

The application discloses a kind of optical storage alternating current coupling system state of charge sensing type frequency power collaborative control method, it is related to new energy power generation and energy storage technical field.The application discloses a kind of optical storage alternating current coupling system state of charge sensing type frequency power collaborative control method, it is related to new energy power generation and energy storage technical field.The application discloses a kind of optical storage alternating current coupling system state of charge sensing type frequency power collaborative control method, it is related to new energy power generation and energy storage technical field.The application discloses a kind of optical storage alternating current coupling system state of charge sensing type frequency power collaborative control method, it is related to new energy power generation and energy storage technical field.The application discloses a kind of optical storage alternating current coupling system state of charge sensing type frequency power collaborative control method, it is related to new energy power generation and energy storage technical field.The application discloses a kind of optical storage alternating current coupling system state of charge sensing type frequency power collaborative control method, it is related to new energy power generation and energy storage technical field.The application discloses a kind of optical storage alternating current coupling system state of charge sensing type frequency power collaborative control method, it is related to new energy power generation and energy storage technical field.The application discloses a kind of optical storage alternating current coupling system state of charge sensing type frequency power collaborative control method, it is related to new energy power generation and energy storage technical field.The application discloses a kind of optical storage alternating current coupling system state of charge sensing type frequency power collaborative control method, it is related to new energy power generation and energy storage technical field.The application discloses a kind of optical storage alternating current coupling system state of charge sensing type frequency power collaborative control method, it is related to new energy power generation and energy storage technical field.The application discloses a kind of optical storage alternating current coupling system state of charge sensing type frequency power collaborative control method, it is related to new energy power generation and energy storage technical field.The application discloses a kind of optical storage alternating current coupling system state of charge sensing type frequency power collaborative control method, it is related to new

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new energy power generation and energy storage technology, in particular to a state of charge aware frequency-power coordinated control method, device and equipment for an AC-coupled photovoltaic and energy storage system and a readable storage medium. BACKGROUND

[0002] With the increasing penetration of renewable energy, off-grid photovoltaic and energy storage hybrid systems are widely used in remote areas, island microgrids and other scenarios. Such systems usually consist of photovoltaic generation units, energy storage systems and loads, and the energy storage battery plays a key role in balancing power generation and power consumption. However, there are still several technical bottlenecks in the actual application of the prior art, mainly including the defects of traditional static power limitation and the hysteresis of photovoltaic power regulation.

[0003] Currently, off-grid photovoltaic and energy storage systems generally use a power distribution strategy based on fixed thresholds. When the battery is close to full charge, the battery charging capacity decreases sharply, which can cause overvoltage, lithium precipitation and other problems, significantly shortening the battery life. At the same time, the current photovoltaic power regulation scheme mostly uses a "power command-feedback control architecture", which requires the transmission of power adjustment signals through a communication network. In the case of communication delay or interference, the photovoltaic system is difficult to respond to changes in the state of the energy storage battery in a timely manner, which may cause system frequency out-of-limit or load power loss problems.

[0004] Therefore, there is an urgent need for a state of charge aware frequency-power coordinated control method for an AC-coupled photovoltaic and energy storage system that can overcome the above-mentioned defects. SUMMARY

[0005] The present application aims to provide a state of charge aware frequency-power coordinated control method, device and equipment for an AC-coupled photovoltaic and energy storage system, which can determine the output power command of the photovoltaic system at the same time by obtaining the battery charge state value of the energy storage system in real time, thereby adjusting the output power command of the photovoltaic system in real time, achieving real-time response of the photovoltaic system to the battery charge state value of the energy storage system, and avoiding system frequency out-of-limit or load power loss problems caused by the photovoltaic system's inability to respond to the battery charge state of the energy storage system in a timely manner.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] In a first aspect, the present application provides a state of charge aware frequency-power coordinated control method for an AC-coupled photovoltaic and energy storage system, which comprises:

[0008] obtaining the battery charge state value of the energy storage system in real time, and determining the reference frequency of the energy storage converter according to the battery charge state value;

[0009] generating a modulation signal of the energy storage converter based on the reference frequency and an output voltage amplitude signal of the energy storage converter;

[0010] synchronously detecting an AC bus voltage frequency of the energy storage converter based on the modulation signal;

[0011] generating an output power instruction of the photovoltaic system according to the AC bus voltage frequency, and controlling the photovoltaic system according to the output power instruction.

[0012] In some embodiments, generating the modulation signal of the energy storage converter based on the reference frequency and the output voltage amplitude signal of the energy storage converter comprises:

[0013] integrating the reference frequency to obtain an angle signal of the output voltage of the energy storage converter;

[0014] calculating voltage instructions of the energy storage converter in a direct axis and a quadrature axis according to the angle signal and the output voltage amplitude signal;

[0015] generating the modulation signal of the energy storage converter according to the voltage instructions of the energy storage converter in the direct axis and the quadrature axis.

[0016] In some embodiments, generating the modulation signal of the energy storage converter according to the voltage instructions of the energy storage converter in the direct axis and the quadrature axis comprises:

[0017] obtaining a current instruction signal of a current inner loop through a PI controller of a voltage loop based on the voltage instructions of the energy storage converter in the direct axis and the quadrature axis;

[0018] obtaining the modulation signal of the energy storage converter through a PI controller of a current loop based on the current instruction signal.

[0019] In some embodiments, the synchronously detecting the AC bus voltage frequency of the energy storage converter based on the modulation signal comprises:

[0020] driving on and off of three-phase bridge arm switching tubes based on the modulation signal of the energy storage converter;

[0021] synchronously detecting the AC bus voltage frequency of the energy storage converter based on the modulation signal through a phase-locked loop.

[0022] In some embodiments, the generating the output power instruction of the photovoltaic system according to the AC bus voltage frequency comprises:

[0023] generating a photovoltaic output limit power of the photovoltaic system according to the AC bus voltage frequency;

[0024] generating the output power instruction of the photovoltaic system based on the photovoltaic output limit power and a maximum output power of the photovoltaic system.

[0025] In some embodiments, the method further comprises:

[0026] determining a battery charging power of the energy storage system according to the battery state of charge value;

[0027] controlling the energy storage system charging based on the battery charging power.

[0028] In a second aspect, the present application further provides a state of charge aware frequency power coordinated control device for a photovoltaic energy storage alternating current coupling system, the device comprising:

[0029] a frequency determining module configured to acquire a battery state of charge value of the energy storage system in real time, and determine a reference frequency of an energy storage converter according to the battery state of charge value;

[0030] a signal generating module configured to generate a modulation signal of the energy storage converter based on the reference frequency and an output voltage amplitude signal of the energy storage converter;

[0031] a frequency detecting module configured to synchronously detect an alternating current bus voltage frequency of the energy storage converter based on the modulation signal;

[0032] a system control module configured to generate an output power instruction of the photovoltaic system according to the alternating current bus voltage frequency, and control the photovoltaic system according to the output power instruction.

[0033] In a third aspect, the present application further provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the state of charge aware frequency power coordinated control method for the photovoltaic energy storage alternating current coupling system when executing the computer program.

[0034] In a fourth aspect, the present application further provides a computer readable storage medium, and the computer readable storage medium stores a computer program, and the computer program is executable on the processor to implement the state of charge aware frequency power coordinated control method for the photovoltaic energy storage alternating current coupling system.

[0035] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, and the computer program is executable on the processor to implement the state of charge aware frequency power coordinated control method for the photovoltaic energy storage alternating current coupling system.

[0036] The beneficial effects of the present application are that: the light storage alternating current coupling system state of charge sensing type frequency power cooperative control method provided in the present application first acquires the battery charge state value of the energy storage system in real time, and determines the reference frequency of the energy storage converter according to the battery charge state value; then generates the modulation signal of the energy storage converter based on the reference frequency and the output voltage amplitude signal of the energy storage converter; then synchronously detects the alternating current bus voltage frequency of the energy storage converter based on the modulation signal; finally generates the output power instruction of the photovoltaic system according to the alternating current bus voltage frequency, and controls the photovoltaic system according to the output power instruction. By acquiring the battery charge state value of the energy storage system in real time, the output power instruction of the photovoltaic system can be determined at the same time, so as to adjust the output power instruction of the photovoltaic system in real time, realize the real-time response of the photovoltaic system to the battery charge state value of the energy storage system, and avoid the system frequency out-of-limit or load power failure problem caused by the photovoltaic system unable to respond to the battery charge state of the energy storage system in time.

[0037] The above description is only a summary of the technical scheme of the present application, in order to more clearly understand the technical means of the present application, and the content of the specification can be implemented. The following is a detailed description of the preferred embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0038] Figure 1 A flowchart of a light storage alternating current coupling system state of charge sensing type frequency power cooperative control method according to an embodiment of the present application is shown.

[0039] Figure 2 A schematic diagram of an off-grid type light storage alternating current coupling system with load according to an embodiment of the present application is shown.

[0040] Figure 3 A schematic diagram of an energy storage converter off-grid load circuit and its control structure according to an embodiment of the present application is shown.

[0041] Figure 4 A constraint relationship curve of the battery charging power and the battery charge state value of the energy storage system according to an embodiment of the present application is shown.

[0042] Figure 5 A power regulation time domain information diagram of an off-grid light storage alternating current coupling system based on the battery charge state value according to an embodiment of the present application is shown.

[0043] Figure 6 A voltage and current change process diagram of the output side of the energy storage converter of an off-grid light storage alternating current coupling system based on the change of the battery charge state value according to an embodiment of the present application is shown.

[0044] Figure 7 A flowchart of another light storage alternating current coupling system state of charge sensing type frequency power cooperative control method according to an embodiment of the present application is shown.

[0045] Figure 8 A structure schematic diagram of a state of charge sensing type frequency power collaborative control device of a light storage alternating current coupling system according to an embodiment of the present application;

[0046] Figure 9 A structure schematic diagram of another state of charge sensing type frequency power collaborative control device of a light storage alternating current coupling system according to an embodiment of the present application;

[0047] Figure 10 An electronic device structure schematic diagram provided by an embodiment of the present application. DETAILED DESCRIPTION

[0048] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0049] It should be noted that the description of "one embodiment", "embodiment", "example embodiment" and the like in the specification means that the described embodiment can include specific features, structures or characteristics, but not every embodiment must include these specific features, structures or characteristics. In addition, such expressions do not mean the same embodiment. Further, when a specific feature, structure or characteristic is described in combination with an embodiment, it is indicated that such a feature, structure or characteristic is combined into other embodiments within the knowledge of those skilled in the art, whether or not it is explicitly described.

[0050] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as there is no conflict.

[0051] In some embodiments, a state of charge sensing type frequency power collaborative control method of a light storage alternating current coupling system is provided, and the specific method comprises:

[0052] S101, a battery charge state value of an energy storage system is acquired in real time, and a reference frequency of an energy storage converter is determined according to the battery charge state value.

[0053] Exemplarily, Figure 2 A schematic diagram of a load of an off-grid type light storage alternating current coupling system, the photovoltaic system and the energy storage system in the diagram both contain LCL filters, is a line reactance value between the photovoltaic system and the alternating current bus, is a line reactance value between the energy storage system and the alternating current bus.

[0054] Figure 3This is a schematic diagram of the off-grid load circuit and control structure of an energy storage converter. Figure 2 In the main circuit, Lif is the machine-side inductance, Cf is the AC-side filter capacitor, Rf is the damping resistor connected in series with the AC-side filter capacitor, Lgf is the grid-side filter inductance of the energy storage converter, Xg is the line reactance value, Vdc is the DC bus voltage of the energy storage converter, V is the machine-side voltage vector, If is the machine-side current vector, Ig is the grid-side current vector, Uf is the capacitor voltage vector, Ug is the load voltage vector, PCC point refers to the grid connection point, and Eg is the AC bus voltage vector.

[0055] exist Figure 3 In the control structure shown, the control of the energy storage converter mainly consists of three parts: a power loop, a voltage inner loop, and a current inner loop. The power loop primarily generates corresponding angular frequency signals through the active power loop and the reactive power loop. and voltage amplitude signal ,Right now:

[0056] ;

[0057] in, and These are the inertia coefficient and damping coefficient of the active loop, respectively. and These are the inertia coefficient and damping coefficient of the reactive power loop, respectively. and These are the active power reference value and the reactive power reference value, respectively. and These are the angular frequency reference value and the voltage amplitude reference value, respectively. and These are the actual active power and reactive power outputs of the energy storage converter, respectively, calculated using the following formula:

[0058] ;

[0059] Specifically, the battery state of charge (SOC) values ​​of the energy storage system can be collected in real time, and different SOC values ​​correspond to different reference frequencies. The correspondence is shown in the following formula:

[0060] ;

[0061] in, For reference frequency, This is the battery state of charge value. This indicates the battery state of charge corresponding to the seamless power point, i.e., when the battery state of charge value exceeds... The energy storage battery has entered a power-limited charging mode. This represents the critical state of charge (SOC) value at which charging stops, i.e., when the SOC value reaches a certain threshold. When the battery SOC reaches the critical value, is the critical battery state of charge value indicating the start of frequency hopping, is the rated frequency of the energy storage converter, i.e., the operating frequency of the energy storage converter in the normal mode, is the operating frequency of the energy storage converter in the hysteresis mode, which is consistent with the frequency of the last update cycle, is the operating frequency of the energy storage converter when the hysteresis mode is turned on, i.e., when the battery state of charge value reaches , and is the operating frequency in the over-frequency mode, is the frequency ramp in the linear frequency ramp mode, and the expression of the frequency ramp is:

[0062] ;

[0063] It should be noted that the frequency values in different operating modes, including the rated frequency , the hysteresis mode start frequency value , the hysteresis mode operating value , the over-frequency mode , and the frequency ramp in the frequency ramp mode , as well as the corresponding critical battery state of charge , and can be customized and adapted according to the battery performance and the actual off-grid system requirements.

[0064] S102, based on the reference frequency and the output voltage amplitude signal of the energy storage converter, a modulation signal of the energy storage converter is generated.

[0065] Specifically, the reference frequency can be integrated first to obtain an angle signal of the output voltage of the energy storage converter, specifically:

[0066] ;

[0067] wherein, is the angle signal of the output voltage of the energy storage converter, is the reference frequency.

[0068] Then, according to the angle signal and the output voltage amplitude signal, the voltage commands of the energy storage converter in the direct axis and the quadrature axis are calculated, specifically:

[0069] ;

[0070] wherein, and are the voltage commands of the direct axis (d-axis) and the quadrature axis (q-axis), respectively.

[0071] The modulation signal of the energy storage converter is generated according to the voltage command of the energy storage converter in the direct axis and the quadrature axis. Specifically, the current command signal of the current inner loop can be obtained through the PI controller of the voltage loop based on the voltage command of the energy storage converter in the direct axis and the quadrature axis:

[0072] ;

[0073] wherein, and are the current command signals of the d-axis and the q-axis respectively, and are the proportional coefficient and the integral coefficient of the voltage controller respectively, and are the d-axis and q-axis components of the actual alternating current output voltage respectively, is the output alternating current capacitance value.

[0074] The modulation signal of the energy storage converter is obtained through the PI controller of the current loop based on the current command signal:

[0075] ;

[0076] wherein, and are the machine-side voltage modulation signals of the d-axis and the q-axis respectively, and are the proportional coefficient and the integral coefficient of the current controller respectively, and are the d-axis and q-axis components of the actual alternating current output current respectively, is the output filter inductance value, and the generated machine-side voltage modulation signals of the d-axis and the q-axis and are converted into the modulation signals in the abc three-phase coordinate system to obtain , and , which are subjected to the pulse width modulation module to generate the PWM modulation signal, i.e., the modulation signal of the energy storage converter, thereby driving the turn-on and turn-off of the three-phase bridge arm switching tube.

[0077] S103, synchronously detecting the alternating bus voltage frequency of the energy storage converter based on the modulation signal.

[0078] Specifically, the turn-on and turn-off of the three-phase bridge arm switching tube can be driven based on the modulation signal of the energy storage converter; and the alternating bus voltage frequency of the energy storage converter based on the modulation signal is synchronously detected through the phase-locked loop.

[0079] S104, generating the output power command of the photovoltaic system according to the alternating bus voltage frequency, and controlling the photovoltaic system according to the output power command.

[0080] Specifically, the photovoltaic output limit power of the photovoltaic system is generated according to the AC bus voltage frequency:

[0081]

[0082] wherein, is the photovoltaic output limit power, is the rated frequency of the energy storage converter, that is, the working frequency of the energy storage converter in the normal mode, is the working frequency of the energy storage converter when the hysteresis mode is started, that is, the battery charge state value reaches , and is the running frequency in the over-frequency mode, is the frequency ramping slope of the energy storage converter in the linear frequency ramping mode.

[0083] Based on the photovoltaic output limit power and the photovoltaic output maximum power, the output power instruction of the photovoltaic system is generated:

[0084]

[0085] wherein, is the photovoltaic output maximum power, is the output power instruction of the photovoltaic system.

[0086] In the above embodiment, the state-of-charge sensing type frequency power collaborative control method of the photovoltaic and energy storage AC coupling system, the battery charge state value of the energy storage system is acquired in real time, and the reference frequency of the energy storage converter is determined according to the battery charge state value; the modulation signal of the energy storage converter is generated based on the reference frequency and the output voltage amplitude signal of the energy storage converter; then the AC bus voltage frequency of the energy storage converter based on the modulation signal is synchronously detected; finally, the output power instruction of the photovoltaic system is generated according to the AC bus voltage frequency, and the photovoltaic system is controlled according to the output power instruction. By acquiring the battery charge state value of the energy storage system in real time, the output power instruction of the photovoltaic system can be determined at the same time, so as to adjust the output power instruction of the photovoltaic system in real time, realize the real-time response of the photovoltaic system to the battery charge state value of the energy storage system, and avoid the system frequency out-of-limit or load power failure problem caused by the photovoltaic system unable to respond to the battery charge state of the energy storage system in time.

[0087] In another embodiment, the battery charging power of the energy storage system also needs to be limited according to the battery charge state value of the energy storage system, that is, the battery charging power of the energy storage system is determined according to the battery charge state value, as shown in Figure 4 Figure 4 is the constraint relationship curve diagram of the battery charging power of the energy storage system and the battery charge state value, and the function expression corresponding to the constraint relationship curve diagram is

[0088] ​​​ ;

[0089] wherein, is the battery charging power of the energy storage system, represents the rated charging power of the energy storage system, represents the battery state of charge value corresponding to the seamless power point, i.e. when the battery state of charge value exceeds , the energy storage battery starts the limited power charging mode, represents the critical state of charge value for stopping charging, i.e. when the battery state of charge value reaches , the energy storage battery prohibits charging. Further, based on the battery charging power, the charging of the energy storage system is controlled.

[0090] The above method can control the charging power of the energy storage system according to the battery state of charge value, thereby preventing the energy storage system from being damaged due to too fast charging.

[0091] In another embodiment, in order to verify the effectiveness of the above method, the following parameters can be set for verification: the DC bus voltage of the energy storage system is 750V, the effective value of the AC voltage is 230V, the DC bus capacitance is 2800μF, the machine-side inductance is 140μH, the AC filter capacitance is 32μF, the grid-side inductance is 5μH, the two state of charge thresholds of the energy storage battery are 90% and 98% respectively, the frequency values of the energy storage converter in different modes are 50Hz, 50.3Hz, and 51Hz, the maximum output power of the photovoltaic system is 60kW.

[0092] Specifically, Figure 5 is a power regulation time domain information diagram of an off-grid photovoltaic energy storage AC coupling system based on the battery state of charge value. Based on Figure 2 the photovoltaic energy storage system architecture diagram, the process of the battery rising from 85% to 98% and then returning to 85% is simulated.

[0093] Figure 6 is a voltage and current change process diagram of the output side of the energy storage converter of the off-grid photovoltaic energy storage AC coupling system based on the change of the battery state of charge value.

[0094] from Figure 5 and Figure 4 ​It can be seen that when the battery state of charge value rises from 85% to 90%, the energy storage system enters the hysteresis mode from the normal mode, and the system frequency rises from the original 50Hz to 50.3Hz. As the battery state of charge value continues to rise, the system enters the linear frequency raising mode, and the system frequency gradually rises, while the output power of the photovoltaic system gradually decreases from the original 1p.u. When the state of charge value of the energy storage battery rises to 98%, the system enters the over frequency mode, and the system frequency rises to 51Hz, while the output power of the photovoltaic gradually decreases to 0. Subsequently, as the battery state of charge value decreases, the system again enters the linear frequency raising mode, the hysteresis mode and the normal mode, and the photovoltaic power gradually rises, thereby verifying the effectiveness of the state of charge sensing type frequency and power collaborative control method of the photovoltaic and energy storage alternating current coupling system.

[0095] In order to more comprehensively show the present scheme, the present embodiment gives an optional way of the state of charge sensing type frequency and power collaborative control method of the photovoltaic and energy storage alternating current coupling system, as shown in Figure 7

[0096] S201, the battery state of charge value of the energy storage system is obtained in real time, and the reference frequency of the energy storage converter is determined according to the battery state of charge value.

[0097] S202, the reference frequency is integrated to obtain an angle signal of the output voltage of the energy storage converter.

[0098] S203, the voltage instructions of the energy storage converter in the direct axis and the quadrature axis are calculated according to the angle signal and the output voltage amplitude signal.

[0099] S204, the current instruction signal of the current inner ring is obtained through the PI controller of the voltage ring based on the voltage instructions of the energy storage converter in the direct axis and the quadrature axis.

[0100] S205, the modulation signal of the energy storage converter is obtained through the PI controller of the current ring based on the current instruction signal.

[0101] S206, the turn-on and turn-off of the three-phase bridge arm switch tube are driven based on the modulation signal of the energy storage converter.

[0102] S207, the alternating current bus voltage frequency of the energy storage converter based on the modulation signal is detected through the phase-locked loop.

[0103] S208, the photovoltaic output limiting power of the photovoltaic system is generated according to the alternating current bus voltage frequency.

[0104] S209, the output power instruction of the photovoltaic system is generated based on the photovoltaic output limiting power and the maximum output power of the photovoltaic.

[0105] S210, the photovoltaic system is controlled according to the output power instruction.​​

[0106] S211, determining, according to the battery charge state value, a battery charging power of the energy storage system.

[0107] S212, controlling, based on the battery charging power, charging of the energy storage system.

[0108] The specific process of S201-S212 can refer to the description of the method embodiments, and the implementation principle and technical effects are similar, which will not be repeated here.

[0109] Based on the same inventive concept, the embodiments of the present application also provide a photovoltaic energy storage alternating current coupling system state of charge aware frequency power collaborative control device for implementing the above-mentioned photovoltaic energy storage alternating current coupling system state of charge aware frequency power collaborative control method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more photovoltaic energy storage alternating current coupling system state of charge aware frequency power collaborative control device embodiments provided below can refer to the limitations of the photovoltaic energy storage alternating current coupling system state of charge aware frequency power collaborative control method described above, and will not be repeated here.

[0110] In one embodiment, as shown in Figure 8 , a photovoltaic energy storage alternating current coupling system state of charge aware frequency power collaborative control device is provided, which comprises:

[0111] A frequency determination module 30 is configured to obtain a battery charge state value of the energy storage system in real time, and determine a reference frequency of the energy storage converter according to the battery charge state value.

[0112] A signal generation module 31 is configured to generate a modulation signal of the energy storage converter based on the reference frequency and an output voltage amplitude signal of the energy storage converter.

[0113] A frequency detection module 32 is configured to synchronously detect an alternating current bus voltage frequency of the energy storage converter based on the modulation signal.

[0114] A system control module 33 is configured to generate an output power instruction of the photovoltaic system according to the alternating current bus voltage frequency, and control the photovoltaic system according to the output power instruction.

[0115] In another embodiment, as shown in Figure 9 , the signal generation module 31 in the above Figure 8 comprises:

[0116] An angle determination unit 310 is configured to integrate the reference frequency to obtain an angle signal of the output voltage of the energy storage converter.

[0117] The instruction calculation unit 311 is configured to calculate voltage instructions of the energy storage converter in the direct axis and the quadrature axis according to the angle signal and the output voltage amplitude signal.

[0118] The signal generation unit 312 is configured to generate a modulation signal of the energy storage converter according to the voltage instructions of the energy storage converter in the direct axis and the quadrature axis.

[0119] In another embodiment, the signal generation unit 312 in the above Figure 9 is specifically configured to obtain a current instruction signal of the current inner loop through a PI controller of the voltage loop based on the voltage instructions of the energy storage converter in the direct axis and the quadrature axis, and obtain the modulation signal of the energy storage converter through a PI controller of the current loop based on the current instruction signal.

[0120] In another embodiment, the signal generation unit 312 in the above Figure 8 is specifically configured to drive on and off of three-phase bridge arm switching tubes based on the modulation signal of the energy storage converter, and detect an AC bus voltage frequency of the energy storage converter based on the modulation signal through a phase-locked loop synchronization.

[0121] In another embodiment, the system control module 33 in the above Figure 8 is specifically configured to generate a photovoltaic output limit power of the photovoltaic system according to the AC bus voltage frequency, and generate an output power instruction of the photovoltaic system based on the photovoltaic output limit power and a photovoltaic output maximum power.

[0122] In another embodiment, the system control module 33 in the above Figure 8 is further configured to determine a battery charging power of the energy storage system according to the battery charge state value, and control charging of the energy storage system based on the battery charging power.

[0123] Embodiments of the present application also provide an electronic device. In some embodiments, as shown in Figure 10 , the electronic device 700 includes an input unit 710, a memory 720, a processor 730, and an output unit 740. The memory 720 stores program instructions executable on the processor 730, and the processor 730 invokes the program instructions to execute the photovoltaic and battery AC coupling system state of charge aware frequency and power collaborative control method and / or technical solutions in the foregoing embodiments. The electronic device 700 can be a mobile terminal device such as a mobile phone or a computer.

[0124] In addition, the embodiment of the present application further provides a computer readable storage medium for storing a computer program for executing the state of charge sensing type frequency power cooperative control method of the optical storage alternating coupling system. For example, the computer program instructions, when executed by a computer, can call or provide the method and / or technical solutions according to the present application through the operation of the computer. The program instructions for calling the method of the present application can be stored in a fixed or removable storage medium, and / or transmitted and / or stored in a storage medium running according to the program instructions through a data stream in a broadcast or other signal bearing medium.

[0125] Obviously, those skilled in the art should understand that the modules or steps of the present application described above can be realized by general computing devices, which can be concentrated on a single computing device or distributed on a network composed of multiple computing devices, and optionally, they can be realized by program codes executable by computing devices, so that they can be stored in storage devices and executed by computing devices, or they can be respectively manufactured into integrated circuit modules, or a plurality of modules or steps among them can be manufactured into a single integrated circuit module to realize. Therefore, the present application is not limited to any specific combination of hardware and software.

[0126] The technical features of the above embodiments can be integrated in any manner. In order to make the description simple, all possible integrations of the technical features in the above embodiments are not described, however, as long as the integration of the technical features does not exist contradictions, it should be considered as the scope of the present application.

[0127] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A state-of-charge sensing frequency-power coordinated control method for a photovoltaic-storage AC coupling system, characterized in that, The method includes: The battery state of charge (SOC) value of the energy storage system is acquired in real time, and the reference frequency of the energy storage converter is determined based on the SOC value. ； in, The reference frequency for the energy storage converter. This is the battery state of charge value. To seamlessly connect the battery state of charge corresponding to the power point, The critical state of charge (SOC) value at which charging can be stopped. This is the critical state of charge value of the battery at which the frequency jump begins. The rated frequency of the energy storage converter. This refers to the operating frequency of the energy storage converter in hysteresis mode. This refers to the operating frequency of the energy storage converter when hysteresis mode is enabled. This refers to the operating frequency of the energy storage converter in overfrequency mode. Let be the frequency ramp slope of the energy storage converter operating in linear ramp mode. The expression for the frequency ramp slope is: ； Based on the reference frequency and the output voltage amplitude signal of the energy storage converter, a modulation signal for the energy storage converter is generated. The frequency of the AC bus voltage of the energy storage converter based on the modulation signal is detected synchronously. The photovoltaic output limit power of the photovoltaic system is generated based on the AC bus voltage frequency. ； in, To limit the photovoltaic output power of the photovoltaic system, This represents the maximum output power of the photovoltaic system. Based on the photovoltaic output limit power and the photovoltaic output maximum power, an output power command for the photovoltaic system is generated, and the photovoltaic system is controlled according to the output power command.

2. The state-of-charge sensing frequency-power coordinated control method for a photovoltaic-storage AC coupling system as described in claim 1, characterized in that, Based on the reference frequency and the output voltage amplitude signal of the energy storage converter, a modulation signal for the energy storage converter is generated, including: Integrating the reference frequency yields the angle signal of the output voltage of the energy storage converter; Based on the angle signal and the output voltage amplitude signal, calculate the voltage commands of the energy storage converter on the direct axis and quadrature axis; Based on the voltage commands of the energy storage converter on the direct axis and quadrature axis, a modulation signal for the energy storage converter is generated.

3. The state-of-charge sensing frequency-power coordinated control method for a photovoltaic-storage AC coupling system as described in claim 2, characterized in that, Based on the voltage commands of the energy storage converter on the direct axis and quadrature axis, a modulation signal for the energy storage converter is generated, including: Based on the voltage commands of the energy storage converter on the direct axis and quadrature axis, the current command signal of the inner current loop is obtained through the PI controller of the voltage loop. Based on the current command signal, the modulation signal of the energy storage converter is obtained through the PI controller of the current loop.

4. The state-of-charge sensing frequency-power coordinated control method for a photovoltaic-storage AC coupling system as described in claim 1, characterized in that, Synchronous detection of the AC bus voltage frequency of the energy storage converter based on the modulation signal includes: The three-phase bridge arm switching transistors are turned on and off based on the modulation signal of the energy storage converter. The frequency of the AC bus voltage of the energy storage converter based on the modulation signal is detected synchronously by a phase-locked loop.

5. The state-of-charge sensing frequency-power coordinated control method for a photovoltaic-storage AC coupling system as described in claim 1, characterized in that, The method further includes: The battery charging power of the energy storage system is determined based on the battery state of charge value. The energy storage system is controlled to charge based on the battery charging power.

6. A state-of-charge sensing frequency-power coordinated control device for a photovoltaic-storage AC coupling system, characterized in that, The device includes: The frequency determination module is used to acquire the battery state-of-charge value of the energy storage system in real time, and determine the reference frequency of the energy storage converter based on the battery state-of-charge value. ； in, The reference frequency for the energy storage converter. This is the battery state of charge value. To seamlessly connect the battery state of charge corresponding to the power point, The critical state of charge (SOC) value at which charging can be stopped. This is the critical state of charge value of the battery at which the frequency jump begins. The rated frequency of the energy storage converter. This refers to the operating frequency of the energy storage converter in hysteresis mode. This refers to the operating frequency of the energy storage converter when hysteresis mode is enabled. This refers to the operating frequency of the energy storage converter in overfrequency mode. Let be the frequency ramp slope of the energy storage converter operating in linear ramp mode. The expression for the frequency ramp slope is: ； The signal generation module is used to generate a modulation signal for the energy storage converter based on the reference frequency and the output voltage amplitude signal of the energy storage converter. A frequency detection module is used to synchronously detect the AC bus voltage frequency of the energy storage converter based on the modulation signal; The system control module is used to generate the photovoltaic output limiting power of the photovoltaic system based on the AC bus voltage frequency. ； in, To limit the photovoltaic output power of the photovoltaic system, This represents the maximum output power of the photovoltaic system. Based on the photovoltaic output limit power and the photovoltaic output maximum power, an output power command for the photovoltaic system is generated, and the photovoltaic system is controlled according to the output power command.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that, When the processor executes the computer program, it implements the state-of-charge sensing frequency-power coordinated control method for the photoelectric-storage AC coupling system as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the state-of-charge sensing frequency-power coordinated control method for an optical-storage AC coupling system as described in any one of claims 1 to 5.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the state-of-charge sensing frequency-power coordinated control method for the photoelectric-storage AC coupling system as described in any one of claims 1 to 5.

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