Power supply system and grid connection control method

Abstract

This application provides a power supply system and grid-connected control method. The power supply system includes a power source, an inverter, a transformer, a power station acquisition module, and an inverter acquisition and control circuit. The power station acquisition module acquires the amplitude and frequency of the grid-connected voltage at the grid connection point and obtains a power station power adjustment signal based on the amplitude and frequency of the grid-connected voltage. The inverter acquisition and control circuit acquires the amplitude and frequency of the inverter's output voltage and obtains an inverter power adjustment signal based on the amplitude and frequency of the output voltage. Based on the power station power adjustment signal and the inverter power adjustment signal, the circuit controls the inverter to output a target output power. Using this application, the output power of the inverter can be adjusted through the power station acquisition module and the inverter acquisition and control circuit. The structure is simple, the control method is convenient, the control accuracy and regulation efficiency are improved, the control time is reduced, and the control cost is lowered.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a power supply system and grid connection control method. Background Technology

[0002] In the field of power electronics technology, with the increasing maturity of various new energy power supply technologies (e.g., photovoltaic power generation), more and more new energy power supply systems are being put into use. Inverters, as the core component of new energy power supply systems, can convert the DC power generated by new energy power plants into AC power and connect it to the power grid. In practical production applications, due to the often changing impedance of the load in the system (or due to the unstable power generation of the new energy power supply system power plant, etc.), the voltage and frequency at the grid connection point of the new energy power supply system and the grid will fluctuate. This will increase the loss of electrical equipment and even endanger equipment safety. During their research and practice, the inventors of this application discovered that in the prior art, inverters are generally equated to current sources, and control is performed based on the linear relationship between the inverter's output voltage (and output frequency) at the detection point and reactive power (and active power). However, this control method is complex and cumbersome, with high control costs, and the linear control method has large errors. Furthermore, the output voltage and output frequency differ between the detection point and the grid connection point, increasing control errors and resulting in poor control performance. Summary of the Invention

[0003] This application provides a power supply system and grid-connected control method, which can adjust the output power of the inverter through the power station acquisition module and the inverter acquisition control circuit. The system has a simple structure, a convenient control method, improves control accuracy and regulation efficiency, reduces control time, and lowers control costs.

[0004] In a first aspect, this application provides a power supply system comprising a power source, an inverter, a transformer, a power station acquisition module, and an inverter acquisition control circuit. Here, the power source can be connected to the inverter and the transformer, the transformer can be connected to the grid at a grid connection point, one end of the power station acquisition module can be connected to the grid connection point, the other end of the power station acquisition module can be connected to the first end of the inverter acquisition control circuit, the second end of the inverter acquisition control circuit can be connected between the inverter and the transformer, and the third end of the inverter acquisition control circuit can be connected to the inverter. The power station acquisition module can be used to acquire the amplitude and frequency of the grid connection voltage at the grid connection point, and obtain a power station power adjustment signal based on the amplitude and frequency of the grid connection voltage. The inverter acquisition control circuit can be used to acquire the amplitude and frequency of the inverter's output voltage, obtain an inverter power adjustment signal based on the amplitude and frequency of the output voltage, and control the inverter to output a target output power based on the power station power adjustment signal and the inverter power adjustment signal.

[0005] In the embodiments provided in this application, the power plant acquisition module can acquire the amplitude and frequency of the grid-connected voltage at the grid connection point. Here, the amplitude and frequency of the grid-connected voltage are related to the power plant power (i.e., the power output by the power supply system at the grid connection point). The system can determine the adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage, thereby obtaining a power plant power adjustment signal. The inverter acquisition and control circuit can acquire the amplitude and frequency of the inverter's output voltage. Here, the amplitude and frequency of the inverter's output voltage are related to the inverter power (i.e., the power output by the inverter). The inverter acquisition and control circuit can determine the adjustment amount of the inverter power based on the amplitude and frequency of the inverter's output voltage, thereby obtaining an inverter power adjustment signal. Since there are other functional modules or power components (e.g., transformers) between the inverter's output terminal and the grid connection point, the inverter acquisition and control circuit can obtain the target adjustment amount of the inverter's output power based on the combined power plant power adjustment signal and the inverter power adjustment signal, and can control the inverter to output the target output power.

[0006] Using the implementation method provided in this application, the system can acquire the amplitude and frequency of the grid-connected voltage at the grid connection point and the output voltage of the inverter through the power station acquisition module and the inverter acquisition control circuit, and determine the power station power adjustment signal and the inverter power adjustment signal respectively. Then, the output power of the inverter is adjusted based on the power station power adjustment signal and the inverter power adjustment signal. The structure is simple, the control method is convenient, the control accuracy and regulation efficiency are improved, the control time is reduced, and the control cost is reduced.

[0007] In conjunction with the first aspect, in a first possible implementation, the inverter acquisition and control circuit may include an inverter acquisition module and a power adjustment module. Here, the first terminal of the power adjustment module can be connected to the power plant acquisition module as the first terminal of the inverter acquisition and control circuit; one terminal of the inverter acquisition module can be connected between the inverter and the transformer as the second terminal of the inverter acquisition and control circuit; the other terminal of the inverter acquisition module can be connected to the second terminal of the power adjustment module; and the third terminal of the power adjustment module can be connected to the inverter as the third terminal of the inverter acquisition and control circuit. The inverter acquisition module can be used to acquire the amplitude and frequency of the inverter's output voltage, obtain the inverter reactive power adjustment amount based on the amplitude of the output voltage, obtain the inverter active power adjustment amount based on the frequency of the output voltage, and obtain an inverter power adjustment signal based on the inverter reactive power adjustment amount and the inverter active power adjustment amount. The power adjustment module can be used to generate an output power adjustment signal based on the power plant power adjustment signal and the inverter power adjustment signal, and control the inverter to output a target output power through the output power adjustment signal. It can be understood that after the inverter acquisition module obtains the amplitude and frequency of the inverter's output voltage, since the amplitude of the inverter's output voltage is non-linearly related to the reactive power adjustment in the inverter power (i.e., the power output by the inverter), and the frequency of the inverter's output voltage is non-linearly related to the active power adjustment in the inverter power (i.e., the power output by the inverter), the inverter acquisition module can determine the reactive power adjustment and active power adjustment of the inverter power based on the amplitude and frequency of the inverter's output voltage, thereby obtaining the inverter power adjustment signal. Furthermore, it can be understood that the power adjustment module can jointly obtain the target adjustment amount of the inverter's output power based on the power station power adjustment signal output by the power station acquisition module and the inverter power adjustment signal output by the inverter acquisition control circuit, and can control the inverter to output the target output power.

[0008] Using the implementation method provided in this application, the inverter acquisition module can determine the reactive power adjustment amount and active power adjustment amount of the inverter power based on the amplitude value and frequency of the inverter's output voltage, thereby obtaining the inverter power adjustment signal. The power adjustment module can jointly obtain the target adjustment amount of the inverter output power based on the power station power adjustment signal output by the power station acquisition module and the inverter power adjustment signal output by the inverter acquisition control circuit, and can control the inverter to output the target output power. The structure is simple. In addition, the system can control the reactive power and active power of the inverter separately, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0009] In conjunction with the first possible implementation of the first aspect, in the second possible implementation, the power plant power adjustment signal may include the power plant reactive power adjustment amount and the power plant active power adjustment amount. The power plant acquisition module here can also be used to obtain the power plant reactive power adjustment amount based on the amplitude value of the grid-connected voltage, obtain the power plant active power adjustment amount based on the frequency of the grid-connected voltage, and output the power plant reactive power adjustment amount and the power plant active power adjustment amount to the inverter acquisition control circuit. It can be understood that after the power plant acquisition module obtains the amplitude value and frequency of the grid-connected voltage, since the amplitude value of the grid-connected voltage is non-linearly related to the reactive power adjustment amount in the power plant power (i.e., the power output by the power supply system at the grid connection point), and the frequency of the grid-connected voltage is non-linearly related to the active power adjustment amount in the power plant power (i.e., the power output by the power supply system at the grid connection point), the power plant acquisition module can determine the reactive power adjustment amount and the active power adjustment amount of the power plant power based on the amplitude value and frequency of the grid-connected voltage at the grid connection point, and then output the power plant reactive power adjustment amount and the power plant active power adjustment amount to the inverter acquisition circuit. Using the implementation method provided in this application, the power plant acquisition module can determine the reactive power adjustment and active power adjustment of the power plant based on the amplitude and frequency of the grid connection voltage at the grid connection point, respectively. Then, it outputs the reactive power adjustment and active power adjustment as power plant power adjustment signals to the power adjustment module in the inverter acquisition circuit. Thus, the power adjustment module can obtain the target reactive power adjustment of the inverter output power based on the power plant reactive power adjustment and the inverter reactive power adjustment, and can also obtain the target active power adjustment of the inverter output power based on the power plant useful power adjustment and the inverter active power adjustment. Furthermore, it can control the inverter to output the target output power (here, the target output power may include the target reactive power and the target active power), resulting in a simple structure. In addition, the system can control the inverter to output the target reactive power and / or the target active power separately, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0010] In conjunction with the first possible implementation of the first aspect, in the third possible implementation, the power plant power adjustment signal may include the amplitude and frequency of the grid-connected voltage. The power plant acquisition module here can also be used to acquire the amplitude and frequency of the grid-connected voltage at the grid connection point and output the amplitude and frequency of the grid-connected voltage at the grid connection point to the inverter acquisition control circuit. Here, in scenarios where the communication speed (or frequency) between the power plant acquisition module and the inverter acquisition control circuit is limited, or in other scenarios where real-time communication between the power plant acquisition module and the inverter acquisition control circuit is inconvenient, the power plant acquisition module can acquire the amplitude and frequency of the grid-connected voltage at the grid connection point and output the amplitude and frequency of the grid-connected voltage at the grid connection point to the inverter acquisition control circuit, which then determines the power plant power adjustment amount based on the amplitude and frequency of the grid-connected voltage. Using the implementation method provided in this application, the system can output the amplitude and frequency of the grid-connected voltage at the grid connection point to the inverter acquisition control circuit through the inverter acquisition control circuit in scenarios where the communication speed (or frequency) between the power plant acquisition module and the inverter acquisition control circuit is limited, or in other scenarios where real-time communication between the power plant acquisition module and the inverter acquisition control circuit is inconvenient. The inverter acquisition control circuit then determines the adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage. The method is simple, flexible, and highly applicable, enriching the applicable scenarios and scope of the system.

[0011] In conjunction with the third possible implementation of the first aspect, in the fourth possible implementation, the inverter acquisition and control circuit may further include a signal confirmation module. Here, the first end of the power adjustment module can be connected to the power station acquisition module through the signal confirmation module. The signal confirmation module can be used to obtain the reactive power adjustment amount of the power station based on the amplitude value of the grid-connected voltage, and to obtain the active power adjustment amount of the power station based on the frequency of the grid-connected voltage, and output the reactive power adjustment amount and the active power adjustment amount of the power station to the power adjustment module. In scenarios where the communication speed (or frequency) between the power station acquisition module and the inverter acquisition and control circuit is limited, or in other scenarios where real-time communication between the power station acquisition module and the inverter acquisition and control circuit is inconvenient, or in scenarios where the power station acquisition module directly transmits the amplitude value and frequency of the grid-connected voltage to the inverter acquisition and control circuit, the signal confirmation module can determine the reactive power adjustment amount and the active power adjustment amount of the power station based on the amplitude value and frequency of the grid-connected voltage at the grid connection point, and then output the reactive power adjustment amount and the active power adjustment amount of the power station as power adjustment signals to the power adjustment module in the inverter acquisition circuit. Therefore, the power adjustment module can obtain the target reactive power adjustment of the inverter output power based on the combined reactive power adjustment of the power station and the inverter, and can also obtain the target active power adjustment of the inverter output power based on the combined useful power adjustment of the power station and the active power adjustment of the inverter. Furthermore, it can control the inverter to output the target output power (here, the target output power can include both target reactive power and target active power), resulting in a simple structure. In addition, the target reactive power and / or target active power of the inverter can be controlled separately, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0012] Using the implementation method provided in this application, in scenarios where the communication speed (or frequency) between the power plant acquisition module and the inverter acquisition control circuit is limited, or in other scenarios where real-time communication between the power plant acquisition module and the inverter acquisition control circuit is inconvenient, or in other scenarios where the power plant acquisition module directly transmits the amplitude and frequency of the grid-connected voltage to the inverter acquisition control circuit, the signal confirmation module can determine the reactive power adjustment amount and active power adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage at the grid connection point, and then output the reactive power adjustment amount and active power adjustment amount of the power plant power as power plant power adjustment signals to the power adjustment module in the inverter acquisition circuit. The method is simple, flexible, and highly applicable, enriching the applicable scenarios and scope of the system. The power adjustment module can obtain the target reactive power adjustment of the inverter output power based on the combined reactive power adjustment of the power station and the inverter, and can also obtain the target active power adjustment of the inverter output power based on the combined useful power adjustment of the power station and the active power adjustment of the inverter. It can control the inverter to output the target output power (here, the target output power can include both target reactive power and target active power), and has a simple structure. Furthermore, the system can control the inverter to output the target reactive power and / or target active power separately, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0013] In conjunction with the second or fourth possible implementation of the first aspect, in the fifth possible implementation, the power adjustment module may further include an adjustment amount confirmation unit and a power control unit. Here, the power control unit is connected to one end of the inverter and the adjustment amount confirmation unit, and the other end of the adjustment amount confirmation unit is connected to the inverter acquisition module, or the other end of the adjustment amount confirmation unit is connected to the signal confirmation module. The adjustment amount confirmation unit can be used to obtain the output reactive power adjustment amount based on the power plant reactive power adjustment amount and the inverter reactive power adjustment amount, to obtain the output active power adjustment amount based on the power plant active power adjustment amount and the inverter active power adjustment amount, and to generate an output power adjustment signal based on the output reactive power adjustment amount and the output active power adjustment amount. The power control unit can be used to control the inverter to output a target output power through the output power adjustment signal. Here, the adjustment confirmation unit (e.g., a proportional-integral amplifier circuit) can obtain the output reactive power adjustment (i.e., the target reactive power adjustment of the inverter output power) based on the reactive power adjustment of the power station and the reactive power adjustment of the inverter. It can also obtain the output active power adjustment (i.e., the target active power adjustment of the inverter output power) based on the useful power adjustment of the power station and the active power adjustment of the inverter. Based on the output reactive power adjustment and the output active power adjustment, it generates an output power adjustment signal (e.g., a pulse-width modulation signal or other control signal that can control the inverter output power). Here, the power control unit can control the inverter to output the target output power (where the target output power may include the target reactive power and the target active power) through the output power adjustment signal, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0014] In conjunction with the fifth possible implementation of the first aspect, in the sixth possible implementation, the inverter reactive power adjustment and the inverter active power adjustment satisfy the following:

[0015] d 2 Q1(u) / du 2 <0

[0016] d 2 P1(f) / df 2 <0

[0017] Here, Q1(u) is a function of the inverter reactive power adjustment with respect to the output voltage amplitude, d 2 Q1(u) / du 2 Let P1(f) be the second derivative of the inverter reactive power adjustment with respect to the output voltage amplitude, and let d be the function of the inverter active power adjustment with respect to the output voltage frequency. 2 P1(f) / df 2 It is the second derivative of the inverter active power adjustment with respect to the output voltage frequency.

[0018] It is understandable that in specific application scenarios, the larger the difference between the output voltage amplitude and the target output voltage amplitude, the larger the corresponding inverter reactive power adjustment. Furthermore, the inverter reactive power adjustment and the output voltage amplitude are not simply linearly related. When the difference between the output voltage amplitude and the target output voltage amplitude increases, the growth rate of the corresponding inverter reactive power adjustment is greater than the growth rate of the difference between the output voltage amplitude and the target output voltage amplitude. Therefore, using Q1(u) (e.g., a quadratic power function) as the fitting function for the inverter reactive power adjustment with respect to the output voltage amplitude can prevent the inverter reactive power adjustment from being too small when the difference between the output voltage amplitude and the target output voltage amplitude is large due to an excessively small linear fitting coefficient, and also prevent the inverter reactive power adjustment from being too large when the difference between the output voltage amplitude and the target output voltage amplitude is small due to an excessively large linear fitting coefficient.

[0019] Furthermore, in specific application scenarios, the larger the difference between the output voltage frequency and the target output voltage frequency, the larger the corresponding inverter active power adjustment. Moreover, the inverter active power adjustment and the output voltage frequency are not simply linearly related. When the difference between the output voltage frequency and the target output voltage frequency increases, the growth rate of the corresponding inverter active power adjustment is greater than the growth rate of the difference between the output voltage frequency and the target output voltage frequency. Therefore, using P1(f) (e.g., a quadratic function) as the function of the inverter active power adjustment with respect to the output voltage frequency can prevent the inverter active power adjustment from being too small when the difference between the output voltage frequency and the target output voltage frequency is large due to an excessively small linear fitting coefficient during linear fitting, and also prevent the inverter active power adjustment from being too large when the difference between the output voltage frequency and the target output voltage frequency is small due to an excessively large linear fitting coefficient.

[0020] Using the implementation method provided in this application, Q1(u) (e.g., a power function) is used as a function of the inverter reactive power adjustment amount with respect to the output voltage amplitude value. This allows for a more accurate determination of the inverter reactive power adjustment amount based on the output voltage amplitude value. The method is simple and improves control accuracy and efficiency. Similarly, using P1(f) (e.g., a power function) as a function of the inverter active power adjustment amount with respect to the output voltage frequency allows for a more accurate determination of the inverter active power adjustment amount based on the output voltage frequency. This method is simple and improves control accuracy and efficiency.

[0021] In conjunction with the sixth possible implementation of the first aspect, in the seventh possible implementation, the reactive power adjustment of the power plant and the active power adjustment of the inverter satisfy the following:

[0022] d 2 Q2(u) / du 2 <0

[0023] d 2 P2(f) / df 2 <0

[0024] Here, Q2(u) is a function of the reactive power adjustment of the power station with respect to the grid voltage amplitude, d 2 Q2(u) / du 2 Let P2(f) be the second derivative of the reactive power adjustment of the power plant with respect to the grid voltage amplitude, and let d be the function of the active power adjustment of the power plant with respect to the grid voltage frequency. 2 P2(f) / df 2 This is the second derivative of the power plant's active power adjustment with respect to the grid-connected voltage frequency.

[0025] It is understandable that in specific application scenarios, the larger the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude, the larger the corresponding reactive power adjustment of the power station. Furthermore, the reactive power adjustment and the grid-connected voltage amplitude are not simply linearly related. When the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude increases, the growth rate of the reactive power adjustment is greater than the growth rate of the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude. Therefore, using Q2(u) (e.g., a quadratic power function) as the fitting function for the reactive power adjustment of the power station with respect to the grid-connected voltage amplitude can prevent the reactive power adjustment from being too small when the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude is large due to an excessively small linear fitting coefficient, and also prevent the reactive power adjustment from being too large when the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude is small due to an excessively large linear fitting coefficient.

[0026] Furthermore, it can be understood that in specific application scenarios, the larger the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency, the larger the corresponding active power adjustment of the power station. Moreover, the active power adjustment of the power station and the grid-connected voltage frequency are not simply linearly related. When the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency increases, the growth rate of the corresponding active power adjustment of the power station is greater than the growth rate of the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency. Therefore, using P2(f) (e.g., a quadratic power function) as the function of the active power adjustment of the power station with respect to the grid-connected voltage frequency can prevent the active power adjustment from being too small when the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency is large due to an excessively small linear fitting coefficient, and also prevent the active power adjustment from being too large when the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency is small due to an excessively large linear fitting coefficient.

[0027] Using the implementation method provided in this application, Q2(u) (e.g., a power function) is used as a function of the reactive power adjustment of the power station with respect to the grid voltage amplitude. This allows for a more accurate determination of the reactive power adjustment based on the grid voltage amplitude, and the method is simple, improving control accuracy and efficiency. Similarly, using P2(f) (e.g., a power function) as a function of the active power adjustment of the power station with respect to the grid voltage frequency allows for a more accurate determination of the active power adjustment based on the grid voltage frequency. This method is simple, and the control accuracy and efficiency are also improved.

[0028] In conjunction with the seventh possible implementation of the first aspect, in the eighth possible implementation, the output reactive power adjustment and the output active power adjustment satisfy the following:

[0029] Qout = Q1 + k1(Q2 - Q1)

[0030] Pout = P1 + k2(P2 - P1)

[0031] Here, Qout is the output reactive power adjustment, Q1 is the inverter reactive power adjustment, Q2 is the power plant reactive power adjustment, k1 is the output reactive power adjustment coefficient, Pout is the output active power adjustment, P1 is the inverter active power adjustment, P2 is the power plant active power adjustment, and k2 is the output active power adjustment coefficient.

[0032] Using the implementation method provided in this application, the system can obtain the output reactive power adjustment Qout (i.e., the target reactive power adjustment of the inverter output power) based on the power station reactive power adjustment Q1 and the inverter reactive power adjustment Q1. It can also obtain the output active power adjustment Pout (i.e., the target active power adjustment of the inverter output power) based on the power station useful power adjustment P1 and the inverter active power adjustment P2. Based on the output reactive power adjustment Qout and the output active power adjustment Pout, the system generates an output power adjustment signal (e.g., a pulse width modulation signal or other control signal that can control the inverter output power), thereby improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0033] In conjunction with the eighth possible implementation of the first aspect, in the ninth possible implementation, the power supply system may further include a combiner box through which the power supply can be connected to the inverter.

[0034] In conjunction with the ninth possible implementation of the first aspect, in the tenth possible implementation, the power supply system may further include a DC bus, the power supply may be connected to the DC bus via a combiner box, and the DC bus may be connected to an inverter.

[0035] In conjunction with the tenth possible implementation of the first aspect, in the eleventh possible implementation, the power supply system may further include a grid connection device, through which the transformer can be connected to the power grid.

[0036] In this application, the functional modules of the power supply system are composed in a variety of flexible ways, which can adapt to different power supply environments, improve the diversity of application scenarios of the power supply system, and enhance the adaptability of the power supply system.

[0037] Secondly, this application provides a grid-connected control method. This method is applicable to a power station acquisition module connected to the grid connection point and an inverter acquisition and control circuit of the power supply system. It is also applicable to the power supply system described in the first aspect or any possible embodiment of the first aspect. The method includes: the power station acquisition module acquiring the amplitude and frequency of the grid connection voltage at the grid connection point, and obtaining a power station power adjustment signal based on the amplitude and frequency of the grid connection voltage; the inverter acquisition and control circuit acquiring the amplitude and frequency of the inverter's output voltage, obtaining an inverter power adjustment signal based on the amplitude and frequency of the output voltage, and controlling the inverter to output a target output power based on the power station power adjustment signal and the inverter power adjustment signal.

[0038] In the embodiments provided in this application, the power plant acquisition module can acquire the amplitude and frequency of the grid-connected voltage at the grid connection point. Here, the amplitude and frequency of the grid-connected voltage are related to the power plant power (i.e., the power output by the power supply system at the grid connection point). The system can determine the adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage, thereby obtaining a power plant power adjustment signal. The inverter acquisition and control circuit can acquire the amplitude and frequency of the inverter's output voltage. Here, the amplitude and frequency of the inverter's output voltage are related to the inverter power (i.e., the power output by the inverter). The inverter acquisition and control circuit can determine the adjustment amount of the inverter power based on the amplitude and frequency of the inverter's output voltage, thereby obtaining an inverter power adjustment signal. Since there are other functional modules or power components (e.g., transformers) between the inverter's output terminal and the grid connection point, the inverter acquisition and control circuit can obtain the target adjustment amount of the inverter's output power based on the combined power plant power adjustment signal and the inverter power adjustment signal, and can control the inverter to output the target output power.

[0039] Using the implementation method provided in this application, the system can acquire the amplitude and frequency of the grid-connected voltage at the grid connection point and the output voltage of the inverter through the power station acquisition module and the inverter acquisition control circuit, and determine the power station power adjustment signal and the inverter power adjustment signal respectively. Then, the output power of the inverter is adjusted based on the power station power adjustment signal and the inverter power adjustment signal. The structure is simple, the control method is convenient, the control accuracy and regulation efficiency are improved, the control time is reduced, and the control cost is reduced.

[0040] In conjunction with the second aspect, in a first possible implementation, the inverter acquisition and control circuit acquires the amplitude and frequency of the output voltage at the inverter output terminal, obtains an inverter power adjustment signal based on the amplitude and frequency of the output voltage, and controls the inverter's output power to the target output power based on the power plant power adjustment signal and the inverter power adjustment signal. This may include: acquiring the amplitude and frequency of the inverter's output voltage; obtaining the inverter reactive power adjustment amount based on the amplitude of the output voltage; obtaining the inverter active power adjustment amount based on the frequency of the output voltage; and obtaining the inverter power adjustment signal based on the inverter reactive power adjustment amount and the inverter active power adjustment amount. An output power adjustment signal is generated based on the power plant power adjustment signal and the inverter power adjustment signal, and the inverter's output power is controlled to the target output power using the output power adjustment signal. It can be understood that after acquiring the amplitude and frequency of the inverter's output voltage, since the amplitude of the inverter's output voltage is non-linearly related to the reactive power adjustment in the inverter power (i.e., the power output by the inverter), and the frequency of the inverter's output voltage is non-linearly related to the active power adjustment in the inverter power (i.e., the power output by the inverter), the inverter acquisition and control circuit can determine the reactive power adjustment and active power adjustment of the inverter power based on the amplitude and frequency of the inverter's output voltage, thereby obtaining the inverter power adjustment signal. Furthermore, it can be understood that the inverter acquisition and control circuit can jointly obtain the target adjustment amount of the inverter's output power based on the power station power adjustment signal output by the power station acquisition module and the inverter power adjustment signal output by the inverter acquisition and control circuit, and can control the inverter to output the target output power.

[0041] Using the implementation method provided in this application, the inverter acquisition and control circuit can determine the reactive power adjustment amount and active power adjustment amount of the inverter power based on the amplitude value and frequency of the inverter's output voltage, thereby obtaining the inverter power adjustment signal. Then, based on the power adjustment signal output by the power station acquisition module and the inverter power adjustment signal output by the inverter acquisition and control circuit, the target adjustment amount of the inverter output power can be obtained, and the inverter can be controlled to output the target output power. The structure is simple. Furthermore, the inverter acquisition and control circuit can control the reactive power and active power of the inverter separately, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0042] In conjunction with the first possible implementation of the second aspect, in the second possible implementation, the power plant power adjustment signal may include the power plant reactive power adjustment amount and the power plant active power adjustment amount. Obtaining the power plant power adjustment signal based on the amplitude and frequency of the grid-connected voltage may include: the power plant acquisition module obtaining the power plant reactive power adjustment amount based on the amplitude of the grid-connected voltage and obtaining the power plant active power adjustment amount based on the frequency of the grid-connected voltage, and outputting the power plant reactive power adjustment amount and the power plant active power adjustment amount to the inverter acquisition control circuit. It can be understood that after the power plant acquisition module obtains the amplitude and frequency of the grid-connected voltage, since the amplitude of the grid-connected voltage is non-linearly related to the reactive power adjustment amount in the power plant power (i.e., the power output by the power supply system at the grid connection point), and the frequency of the grid-connected voltage is non-linearly related to the active power adjustment amount in the power plant power (i.e., the power output by the power supply system at the grid connection point), the power plant acquisition module can determine the reactive power adjustment amount and the active power adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage at the grid connection point, and then output the power plant reactive power adjustment amount and the power plant active power adjustment amount to the inverter acquisition circuit. Using the implementation method provided in this application, the power plant acquisition module can determine the reactive power adjustment and active power adjustment of the power plant based on the amplitude and frequency of the grid connection voltage at the grid connection point, respectively. Then, it outputs the reactive power adjustment and active power adjustment as power plant power adjustment signals to the power adjustment module in the inverter acquisition circuit. Thus, the power adjustment module can obtain the target reactive power adjustment of the inverter output power based on the power plant reactive power adjustment and the inverter reactive power adjustment, and can also obtain the target active power adjustment of the inverter output power based on the power plant useful power adjustment and the inverter active power adjustment. Furthermore, it can control the inverter to output the target output power (here, the target output power may include the target reactive power and the target active power), resulting in a simple structure. In addition, the system can control the inverter to output the target reactive power and / or the target active power separately, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0043] In conjunction with the first possible implementation of the second aspect, in the third possible implementation, the power plant power adjustment signal may include the amplitude and frequency of the grid-connected voltage. Obtaining the power plant power adjustment signal based on the amplitude and frequency of the grid-connected voltage may include: the power plant acquisition module acquiring the amplitude and frequency of the grid-connected voltage at the grid connection point, and outputting the amplitude and frequency of the grid-connected voltage at the grid connection point to the inverter acquisition and control circuit.

[0044] Using the implementation method provided in this application, the system can output the amplitude and frequency of the grid-connected voltage at the grid connection point to the inverter acquisition control circuit through the inverter acquisition control circuit in scenarios where the communication speed (or frequency) between the power plant acquisition module and the inverter acquisition control circuit is limited, or in other scenarios where real-time communication between the power plant acquisition module and the inverter acquisition control circuit is inconvenient. The inverter acquisition control circuit then determines the adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage. The method is simple, flexible, and highly applicable, enriching the applicable scenarios and scope of the system.

[0045] In conjunction with the third possible implementation of the second aspect, in the fourth possible implementation, after outputting the amplitude and frequency of the grid-connected voltage at the grid connection point to the inverter acquisition and control circuit, the method may include: obtaining the reactive power adjustment amount of the power station based on the amplitude of the grid-connected voltage, obtaining the active power adjustment amount of the power station based on the frequency of the grid-connected voltage, and outputting the reactive power adjustment amount and the active power adjustment amount of the power station. Here, in scenarios where the communication speed (or frequency) between the power station acquisition module and the inverter acquisition and control circuit is limited, or in other scenarios where real-time communication between the power station acquisition module and the inverter acquisition and control circuit is inconvenient, or in other scenarios where the power station acquisition module directly transmits the amplitude and frequency of the grid-connected voltage to the inverter acquisition and control circuit, the inverter acquisition and control circuit can determine the reactive power adjustment amount and the active power adjustment amount of the power station power based on the amplitude and frequency of the grid-connected voltage at the grid connection point, and then output the reactive power adjustment amount and the active power adjustment amount of the power station power as power station adjustment signals. Therefore, the inverter acquisition and control circuit can obtain the target reactive power adjustment of the inverter output power based on the combined reactive power adjustment of the power station and the inverter, and can also obtain the target active power adjustment of the inverter output power based on the combined useful power adjustment of the power station and the active power adjustment of the inverter. Furthermore, it can control the inverter to output the target output power (here, the target output power can include both target reactive power and target active power), resulting in a simple structure. In addition, the inverter acquisition and control circuit can separately control the inverter to output the target reactive power and / or target active power, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0046] Using the implementation method provided in this application, in scenarios where the communication speed (or frequency) between the power plant acquisition module and the inverter acquisition control circuit is limited, or in other scenarios where real-time communication between the power plant acquisition module and the inverter acquisition control circuit is inconvenient, or in other scenarios where the power plant acquisition module directly transmits the amplitude and frequency of the grid-connected voltage to the inverter acquisition control circuit, the inverter acquisition control circuit can determine the reactive power adjustment amount and active power adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage at the grid connection point, and then output the reactive power adjustment amount and active power adjustment amount of the power plant power as power plant power adjustment signals. The method is simple, flexible, and highly applicable, enriching the applicable scenarios and scope of the system. The inverter acquisition control circuit can obtain the target reactive power adjustment amount of the inverter output power based on the combined reactive power adjustment amount of the power plant and the inverter reactive power adjustment amount, and can also obtain the target active power adjustment amount of the inverter output power based on the combined active power adjustment amount of the power plant and the inverter active power adjustment amount, and can control the inverter to output the target output power (here, the target output power may include the target reactive power and the target active power), with a simple structure. In addition, the inverter acquisition and control circuit can control the inverter output target reactive power and / or target active power separately, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0047] In a fifth possible implementation, combining the second or fourth possible implementation of the second aspect, an output power adjustment signal is generated based on the power plant power adjustment signal and the inverter power adjustment signal. The output power of the inverter is then controlled to the target output power using this output power adjustment signal. This may include: obtaining an output reactive power adjustment based on the power plant reactive power adjustment and the inverter reactive power adjustment; obtaining an output active power adjustment based on the power plant active power adjustment and the inverter active power adjustment; and generating the output power adjustment signal based on the output reactive power adjustment and the output active power adjustment. The inverter is then controlled to output the target output power using the output power adjustment signal. Here, the inverter acquisition and control circuit can obtain the output reactive power adjustment (i.e., the target reactive power adjustment of the inverter output power) based on the reactive power adjustment of the power station and the reactive power adjustment of the inverter. It can also obtain the output active power adjustment (i.e., the target active power adjustment of the inverter output power) based on the useful power adjustment of the power station and the active power adjustment of the inverter. Furthermore, it generates an output power adjustment signal (e.g., a pulse width modulation signal or other control signal that can control the inverter output power) based on the output reactive power adjustment and the output active power adjustment. The inverter acquisition and control circuit can also control the inverter to output a target output power (where the target output power can include both target reactive power and target active power) through the output power adjustment signal, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0048] In conjunction with the fifth possible implementation of the second aspect, in the sixth possible implementation, the inverter reactive power adjustment and the inverter active power adjustment satisfy the following:

[0049] d 2 Q1(u) / du 2 <0

[0050] d 2 P1(f) / df 2 <0

[0051] Here, Q1(u) is a function of the inverter reactive power adjustment with respect to the output voltage amplitude, d 2 Q1(u) / du 2 Let P1(f) be the second derivative of the inverter reactive power adjustment with respect to the output voltage amplitude, and let d be the function of the inverter active power adjustment with respect to the output voltage frequency. 2 P1(f) / df 2 It is the second derivative of the inverter active power adjustment with respect to the output voltage frequency.

[0052] It is understandable that in specific application scenarios, the larger the difference between the output voltage amplitude and the target output voltage amplitude, the larger the corresponding inverter reactive power adjustment. Furthermore, the inverter reactive power adjustment and the output voltage amplitude are not simply linearly related. When the difference between the output voltage amplitude and the target output voltage amplitude increases, the growth rate of the corresponding inverter reactive power adjustment is greater than the growth rate of the difference between the output voltage amplitude and the target output voltage amplitude. Therefore, using Q1(u) (e.g., a quadratic power function) as the fitting function for the inverter reactive power adjustment with respect to the output voltage amplitude can prevent the inverter reactive power adjustment from being too small when the difference between the output voltage amplitude and the target output voltage amplitude is large due to an excessively small linear fitting coefficient, and also prevent the inverter reactive power adjustment from being too large when the difference between the output voltage amplitude and the target output voltage amplitude is small due to an excessively large linear fitting coefficient.

[0053] Furthermore, in specific application scenarios, the larger the difference between the output voltage frequency and the target output voltage frequency, the larger the corresponding inverter active power adjustment. Moreover, the inverter active power adjustment and the output voltage frequency are not simply linearly related. When the difference between the output voltage frequency and the target output voltage frequency increases, the growth rate of the corresponding inverter active power adjustment is greater than the growth rate of the difference between the output voltage frequency and the target output voltage frequency. Therefore, using P1(f) (e.g., a quadratic function) as the function of the inverter active power adjustment with respect to the output voltage frequency can prevent the inverter active power adjustment from being too small when the difference between the output voltage frequency and the target output voltage frequency is large due to an excessively small linear fitting coefficient during linear fitting, and also prevent the inverter active power adjustment from being too large when the difference between the output voltage frequency and the target output voltage frequency is small due to an excessively large linear fitting coefficient.

[0054] Using the implementation method provided in this application, Q1(u) (e.g., a power function) is used as a function of the inverter reactive power adjustment amount with respect to the output voltage amplitude value. This allows for a more accurate determination of the inverter reactive power adjustment amount based on the output voltage amplitude value. The method is simple and improves control accuracy and efficiency. Similarly, using P1(f) (e.g., a power function) as a function of the inverter active power adjustment amount with respect to the output voltage frequency allows for a more accurate determination of the inverter active power adjustment amount based on the output voltage frequency. This method is simple and improves control accuracy and efficiency.

[0055] In conjunction with the sixth possible implementation method of the second aspect, in the seventh possible implementation method, the reactive power adjustment of the power plant and the active power adjustment of the inverter satisfy the following:

[0056] d 2 Q2(u) / du 2 <0

[0057] d 2 P2(f) / df 2 <0

[0058] Here, Q2(u) is a function of the reactive power adjustment of the power station with respect to the grid voltage amplitude, d 2 Q2(u) / du 2 Let P2(f) be the second derivative of the reactive power adjustment of the power plant with respect to the grid voltage amplitude, and let d be the function of the active power adjustment of the power plant with respect to the grid voltage frequency. 2 P2(f) / df 2 This is the second derivative of the power plant's active power adjustment with respect to the grid-connected voltage frequency.

[0059] It is understandable that in specific application scenarios, the larger the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude, the larger the corresponding reactive power adjustment of the power station. Furthermore, the reactive power adjustment and the grid-connected voltage amplitude are not simply linearly related. When the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude increases, the growth rate of the reactive power adjustment is greater than the growth rate of the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude. Therefore, using Q2(u) (e.g., a quadratic power function) as the fitting function for the reactive power adjustment of the power station with respect to the grid-connected voltage amplitude can prevent the reactive power adjustment from being too small when the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude is large due to an excessively small linear fitting coefficient, and also prevent the reactive power adjustment from being too large when the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude is small due to an excessively large linear fitting coefficient.

[0060] Furthermore, it can be understood that in specific application scenarios, the larger the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency, the larger the corresponding active power adjustment of the power station. Moreover, the active power adjustment of the power station and the grid-connected voltage frequency are not simply linearly related. When the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency increases, the growth rate of the corresponding active power adjustment of the power station is greater than the growth rate of the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency. Therefore, using P2(f) (e.g., a quadratic power function) as the function of the active power adjustment of the power station with respect to the grid-connected voltage frequency can prevent the active power adjustment from being too small when the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency is large due to an excessively small linear fitting coefficient, and also prevent the active power adjustment from being too large when the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency is small due to an excessively large linear fitting coefficient.

[0061] Using the implementation method provided in this application, Q2(u) (e.g., a power function) is used as a function of the reactive power adjustment of the power station with respect to the grid voltage amplitude. This allows for a more accurate determination of the reactive power adjustment based on the grid voltage amplitude, and the method is simple, improving control accuracy and efficiency. Similarly, using P2(f) (e.g., a power function) as a function of the active power adjustment of the power station with respect to the grid voltage frequency allows for a more accurate determination of the active power adjustment based on the grid voltage frequency. This method is simple, and the control accuracy and efficiency are also improved.

[0062] In conjunction with the seventh possible implementation of the second aspect, in the eighth possible implementation, the output reactive power adjustment and the output active power adjustment satisfy the following:

[0063] Qout = Q1 + k1(Q2 - Q1)

[0064] Pout = P1 + k2(P2 - P1)

[0065] Here, Qout is the output reactive power adjustment, Q1 is the inverter reactive power adjustment, Q2 is the power plant reactive power adjustment, k1 is the output reactive power adjustment coefficient, Pout is the output active power adjustment, P1 is the inverter active power adjustment, P2 is the power plant active power adjustment, and k2 is the output active power adjustment coefficient.

[0066] Using the implementation method provided in this application, the system can obtain the output reactive power adjustment Qout (i.e., the target reactive power adjustment of the inverter output power) based on the power station reactive power adjustment Q1 and the inverter reactive power adjustment Q1. It can also obtain the output active power adjustment Pout (i.e., the target active power adjustment of the inverter output power) based on the power station useful power adjustment P1 and the inverter active power adjustment P2. Based on the output reactive power adjustment Qout and the output active power adjustment Pout, the system generates an output power adjustment signal (e.g., a pulse width modulation signal or other control signal that can control the inverter output power), thereby improving control accuracy and regulation efficiency, reducing control time, and lowering control costs. Attached Figure Description

[0067] Figure 1 This is a schematic diagram of an application scenario for the power supply system provided in the embodiments of this application;

[0068] Figure 2 This is a schematic diagram of the power supply system provided in an embodiment of this application;

[0069] Figure 3 This is another structural schematic diagram of the power supply system provided in the embodiments of this application;

[0070] Figure 4 This is a schematic diagram of the relationship between the active power adjustment amount and frequency of the power supply system provided in the embodiments of this application;

[0071] Figure 5 This is another structural schematic diagram of the power supply system provided in the embodiments of this application;

[0072] Figure 6 This is another structural schematic diagram of the power supply system provided in the embodiments of this application;

[0073] Figure 7 This is another structural schematic diagram of the power supply system provided in the embodiments of this application;

[0074] Figure 8 This is another structural schematic diagram of the power supply system provided in the embodiments of this application;

[0075] Figure 9This is a schematic flowchart of the grid connection control method provided in an embodiment of this application;

[0076] Figure 10 This is another schematic flowchart of the grid connection control method provided in the embodiments of this application. Detailed Implementation

[0077] The power supply system provided in this application can be applied to various fields, including new energy smart microgrids, power transmission and distribution, new energy fields (such as photovoltaic grid-connected fields, thermal power grid-connected fields, or wind power grid-connected fields), photovoltaic power generation, wind power generation, thermal power generation, or high-power converter fields (such as converting DC power to high-power high-voltage AC power), etc. The specific application scenario can be determined accordingly, and no restrictions are imposed here. The power supply system provided in this application can be applied to power supply systems with different power generation devices, such as photovoltaic power supply systems, wind power supply systems, thermal power supply systems, nuclear power supply systems, chemical power supply systems, or biomass power supply systems. The specific application scenario can be determined according to the actual application scenario, and no restrictions are imposed here. The power supply system provided in this application can be adapted to different application scenarios, such as powering loads in photovoltaic-storage power supply environments, wind-storage power supply environments, pure energy storage power supply environments, or other application scenarios. The following will use the application scenario of powering loads in a pure energy storage power supply environment as an example for explanation, and will not be elaborated further.

[0078] Please see Figure 1 , Figure 1 This is a schematic diagram illustrating an application scenario of the power supply system provided in this application embodiment. In a pure energy storage power supply application scenario, such as... Figure 1As shown, the power supply system 1 includes a power source 11, an inverter 12, a transformer 13, a power station acquisition module 14, and an inverter acquisition control circuit 10. The power source 11 can be connected to the inverter 12 and the transformer 13. The transformer 13 can be connected to the power grid 2 at a grid connection point. One end of the power station acquisition module 14 can be connected to the grid connection point, and the other end can be connected to the first end of the inverter acquisition control circuit 10. The second end of the inverter acquisition control circuit 10 can be connected between the inverter 12 and the transformer 13, and the third end of the inverter acquisition control circuit 10 can be connected to the inverter 12. In some feasible embodiments, the power source 11 can supply power to the power grid 2 through the inverter 12 and the transformer 13. In some feasible embodiments, the power source 11 can also be connected to a load 3 through the inverter 12 and the transformer 13, and supply power to the load 3 through the inverter 12 and the transformer 13. Here, inverter 12 converts the DC power supplied by power source 11 into AC power, and transformer 13 boosts (or reduces) the AC voltage to match the voltage of grid 2 (or load 3). In some feasible implementations, power source 11 can also serve as an energy storage device. When power is not scarce, power source 11 can obtain and store the electrical energy supplied by grid 2 through inverter 12 and transformer 13. This application only describes the application scenario of power source 11 supplying power to grid 2 (or load 3) through inverter 12 and transformer 13, and will not elaborate further below. It can be understood that the power source 11 provided in this application is suitable for supplying power to base station equipment in remote areas with no mains power or poor mains power, or for powering batteries, or for powering household appliances (such as refrigerators, air conditioners, etc.), etc., in various application scenarios. The specific application scenario can be determined according to the actual application scenario, and no limitation is made here. It can be further understood that... Figure 1The power grid 2 in this context can include power transmission lines, power transfer stations, batteries, communication base stations, or household appliances and other electrical equipment or power transmission equipment. The load 3 can include motors, rectifiers, and other loads (electrical devices or power transmission devices) whose voltage and current relationships are non-linear during operation (power supply or consumption). It is understood that the impedance at the power grid 2 (or load 3) terminals typically changes during operation, or when the power source 11 is a renewable energy power station (e.g., a photovoltaic power station), the power generation may be unstable (e.g., changes in sunlight conditions at the photovoltaic power station). In these scenarios (or other application scenarios), the voltage and frequency at the grid connection point between the power supply system 1 and the power grid 2 will fluctuate, potentially increasing equipment losses or even jeopardizing equipment safety. Here, the power plant acquisition module 14 can acquire the amplitude and frequency of the grid connection voltage at the grid connection point, and obtain the power plant power adjustment signal based on the amplitude and frequency of the grid connection voltage. The inverter acquisition and control circuit 10 can acquire the amplitude and frequency of the output voltage of the inverter 12, and obtain the inverter power adjustment signal based on the amplitude and frequency of the output voltage. Based on the power plant power adjustment signal and the inverter power adjustment signal, the inverter 12 is controlled to output the target output power. The structure is simple, the control method is convenient, the control accuracy and regulation efficiency are improved, the control time is reduced, and the control cost is reduced.

[0079] The following will combine Figures 2 to 10 The power supply system provided in this application and its working principle are illustrated with examples.

[0080] Please see Figure 2 , Figure 2 This is a schematic diagram of the power supply system provided in an embodiment of this application. For example... Figure 2 As shown, the power supply system includes a power supply 101, an inverter 102, a transformer 103, a power station acquisition module 104, and an inverter acquisition control circuit 100. Here, the power supply 101 can be connected to the inverter 102 and the transformer 103. The transformer 103 can be connected to the grid at the grid connection point. One end of the power station acquisition module 104 can be connected to the grid connection point, and the other end of the power station acquisition module 104 can be connected to the first end of the inverter acquisition control circuit 100. The second end of the inverter acquisition control circuit 100 can be connected between the inverter 102 and the transformer 103, and the third end of the inverter acquisition control circuit 100 can be connected to the inverter 102. The power station acquisition module 104 can be used to acquire the amplitude and frequency of the grid connection voltage at the grid connection point, and obtain a power station power adjustment signal based on the amplitude and frequency of the grid connection voltage. The inverter acquisition and control circuit 100 here can be used to acquire the amplitude and frequency of the output voltage of the inverter 102, obtain the inverter power adjustment signal based on the amplitude and frequency of the output voltage, and control the inverter 102 to output the target output power based on the power station power adjustment signal and the inverter power adjustment signal.

[0081] In the embodiments provided in this application, the power plant acquisition module 104 can acquire the amplitude and frequency of the grid-connected voltage at the grid connection point. Here, the amplitude and frequency of the grid-connected voltage are related to the power plant power (i.e., the power output by the power supply system at the grid connection point). The system can determine the adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage, thereby obtaining a power plant power adjustment signal. The inverter acquisition control circuit 100 can acquire the amplitude and frequency of the output voltage of the inverter 102. Here, the amplitude and frequency of the output voltage of the inverter 102 are related to the inverter power (i.e., the power output by the inverter 102). The inverter acquisition control circuit 100 can determine the adjustment amount of the inverter power based on the amplitude and frequency of the output voltage of the inverter 102, thereby obtaining an inverter power adjustment signal. Since there are other functional modules or power components (e.g., transformer 103) between the output terminal of inverter 102 and the grid connection point, inverter acquisition and control circuit 100 can obtain the target adjustment amount of inverter 102 output power based on the power station power adjustment signal and inverter power adjustment signal, and can control inverter 102 to output the target output power.

[0082] Using the implementation method provided in this application, the system can acquire the grid connection voltage at the grid connection point and the amplitude and frequency of the output voltage of the inverter 102 through the power station acquisition module 104 and the inverter acquisition control circuit 100, and determine the power station power adjustment signal and the inverter power adjustment signal respectively. Then, the output power of the inverter 102 is adjusted based on the power station power adjustment signal and the inverter power adjustment signal. The structure is simple, the control method is convenient, the control accuracy and regulation efficiency are improved, the control time is reduced, and the control cost is reduced.

[0083] In some feasible implementations, the inverter acquisition control circuit may include an inverter acquisition module and a power adjustment module; please refer to the following for details. Figure 3 , Figure 3 This is another structural schematic diagram of the power supply system provided in an embodiment of this application. For example... Figure 3As shown, the inverter acquisition and control circuit 200 may include an inverter acquisition module 205 and a power adjustment module 206. Here, the power supply 201 can be connected to the inverter 202 and the transformer 203. The transformer 203 can be connected to the grid at the grid connection point. One end of the power station acquisition module 204 can be connected to the grid connection point, and the other end of the power station acquisition module 204 can be connected to the first end of the inverter acquisition and control circuit 200. The second end of the inverter acquisition and control circuit 200 can be connected between the inverter 202 and the transformer 203, and the third end of the inverter acquisition and control circuit 200 can be connected to the inverter 202. Here, the first terminal of the power adjustment module 206 can be connected to the power station acquisition module 204 as the first terminal of the inverter acquisition control circuit 200. One terminal of the inverter acquisition module 205 can be connected between the inverter 202 and the transformer 203 as the second terminal of the inverter acquisition control circuit 200. The other terminal of the inverter acquisition module 205 can be connected to the second terminal of the power adjustment module 206. The third terminal of the power adjustment module 206 can be connected to the inverter 202 as the third terminal of the inverter acquisition control circuit 200. The inverter acquisition module 205 can be used to acquire the amplitude and frequency of the output voltage of the inverter 202. Based on the amplitude of the output voltage, it obtains the inverter reactive power adjustment amount; based on the frequency of the output voltage, it obtains the inverter active power adjustment amount; and based on the inverter reactive power adjustment amount and the inverter active power adjustment amount, it obtains the inverter power adjustment signal. The power adjustment module 206 can be used to generate an output power adjustment signal based on the power station power adjustment signal and the inverter power adjustment signal, and control the inverter 202 to output the target output power through the output power adjustment signal. It can be understood that after the inverter acquisition module 205 acquires the amplitude and frequency of the inverter 202's output voltage, since the amplitude of the inverter 202's output voltage is non-linearly related to the reactive power adjustment in the inverter power (i.e., the power output by the inverter 202), and the frequency of the inverter 202's output voltage is non-linearly related to the active power adjustment in the inverter power (i.e., the power output by the inverter 202), the inverter acquisition module 205 can determine the reactive power adjustment and active power adjustment of the inverter power based on the amplitude and frequency of the inverter 202's output voltage, thereby obtaining the inverter power adjustment signal. Furthermore, it can be understood that the power adjustment module 206 can jointly obtain the target adjustment amount of the inverter 202's output power based on the power station power adjustment signal output by the power station acquisition module 204 and the inverter power adjustment signal output by the inverter acquisition control circuit 200, and can control the inverter 202 to output the target output power.

[0084] Using the implementation method provided in this application, the inverter acquisition module 205 can determine the reactive power adjustment amount and active power adjustment amount of the inverter power based on the amplitude value and frequency of the output voltage of the inverter 202, and thus obtain the inverter power adjustment signal. The power adjustment module 206 can obtain the target adjustment amount of the output power of the inverter 202 based on the power adjustment signal output by the power station acquisition module 204 and the inverter power adjustment signal output by the inverter acquisition control circuit 200, and can control the inverter 202 to output the target output power. The structure is simple. In addition, the system can control the reactive power and active power of the inverter 202 separately, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0085] In some feasible implementations, the power plant power adjustment signal may include the power plant reactive power adjustment amount and the power plant active power adjustment amount. The power plant acquisition module 204 can also be used to obtain the power plant reactive power adjustment amount based on the amplitude value of the grid-connected voltage, and to obtain the power plant active power adjustment amount based on the frequency of the grid-connected voltage, and output the power plant reactive power adjustment amount and power plant active power adjustment amount to the inverter acquisition control circuit 200. It can be understood that after the power plant acquisition module 204 acquires the amplitude value and frequency of the grid-connected voltage, since the amplitude value of the grid-connected voltage is non-linearly related to the reactive power adjustment amount in the power plant power (i.e., the power output by the power supply system at the grid connection point), and the frequency of the grid-connected voltage is non-linearly related to the active power adjustment amount in the power plant power (i.e., the power output by the power supply system at the grid connection point), the power plant acquisition module 204 can determine the reactive power adjustment amount and active power adjustment amount of the power plant power based on the amplitude value and frequency of the grid-connected voltage at the grid connection point, and then output the power plant reactive power adjustment amount and power plant active power adjustment amount to the inverter acquisition circuit. Using the implementation method provided in this application, the power plant acquisition module 204 can determine the reactive power adjustment and active power adjustment of the power plant based on the amplitude and frequency of the grid connection voltage at the grid connection point, and then output the reactive power adjustment and active power adjustment as power plant power adjustment signals to the power adjustment module 206 in the inverter acquisition circuit. Therefore, the power adjustment module 206 can obtain the target reactive power adjustment of the inverter 202 output power based on the power plant reactive power adjustment and the inverter reactive power adjustment, and can also obtain the target active power adjustment of the inverter 202 output power based on the power plant useful power adjustment and the inverter active power adjustment, and can control the inverter 202 to output the target output power (here, the target output power may include the target reactive power and the target active power), with a simple structure. Furthermore, the system can control the inverter 202 to output the target reactive power and / or the target active power separately, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0086] In some feasible implementations, the inverter reactive power adjustment and the inverter active power adjustment satisfy the following formula:

[0087] d 2 Q1(u) / du 2 <0 (1)

[0088] d 2 P1(f) / df 2 <0 (2)

[0089] Here, Q1(u) is a function of the inverter reactive power adjustment with respect to the output voltage amplitude, d 2 Q1(u) / du 2 Let P1(f) be the second derivative of the inverter reactive power adjustment with respect to the output voltage amplitude, and let d be the function of the inverter active power adjustment with respect to the output voltage frequency. 2 P1(f) / df 2 It is the second derivative of the inverter active power adjustment with respect to the output voltage frequency.

[0090] It is understandable that in specific application scenarios, the larger the difference between the output voltage amplitude and the target output voltage amplitude, the larger the corresponding inverter reactive power adjustment. Furthermore, the inverter reactive power adjustment and the output voltage amplitude are not simply linearly related. When the difference between the output voltage amplitude and the target output voltage amplitude increases, the growth rate of the corresponding inverter reactive power adjustment is greater than the growth rate of the difference between the output voltage amplitude and the target output voltage amplitude. Therefore, using Q1(u) (e.g., a quadratic power function) as the fitting function for the inverter reactive power adjustment with respect to the output voltage amplitude can prevent the inverter reactive power adjustment from being too small when the difference between the output voltage amplitude and the target output voltage amplitude is large due to an excessively small linear fitting coefficient, and also prevent the inverter reactive power adjustment from being too large when the difference between the output voltage amplitude and the target output voltage amplitude is small due to an excessively large linear fitting coefficient.

[0091] Furthermore, in specific application scenarios, the larger the difference between the output voltage frequency and the target output voltage frequency, the larger the corresponding inverter active power adjustment. Moreover, the inverter active power adjustment and the output voltage frequency are not simply linearly related. When the difference between the output voltage frequency and the target output voltage frequency increases, the growth rate of the corresponding inverter active power adjustment is greater than the growth rate of the difference between the output voltage frequency and the target output voltage frequency. Therefore, using P1(f) (e.g., a quadratic function) as the function of the inverter active power adjustment with respect to the output voltage frequency can prevent the inverter active power adjustment from being too small when the difference between the output voltage frequency and the target output voltage frequency is large due to an excessively small linear fitting coefficient during linear fitting, and also prevent the inverter active power adjustment from being too large when the difference between the output voltage frequency and the target output voltage frequency is small due to an excessively large linear fitting coefficient.

[0092] In some feasible implementations, the inverter reactive power adjustment and inverter active power adjustment can satisfy the following formula:

[0093] Q1 = k11·(U0-U1) 2 (3)

[0094] P1 = k12·(f0-f1) 2 (4)

[0095] Where Q1 is the inverter reactive power adjustment amount, U0 is the target output voltage amplitude value, U1 is the output voltage amplitude value, k11 is the inverter reactive power adjustment coefficient, P1 is the inverter reactive power adjustment amount, f0 is the target output voltage frequency, f1 is the output voltage frequency, and k12 is the inverter active power adjustment coefficient.

[0096] Using the implementation method provided in this application, Q1(u) (e.g., the quadratic power function shown in Formula 3) is used as a function of the inverter reactive power adjustment amount with respect to the output voltage amplitude value. This allows for a more accurate determination of the inverter reactive power adjustment amount based on the output voltage amplitude value. The method is simple and improves control accuracy and efficiency. Similarly, using P1(f) (e.g., the quadratic power function shown in Formula 4) as a function of the inverter active power adjustment amount with respect to the output voltage frequency allows for a more accurate determination of the inverter active power adjustment amount based on the output voltage frequency. This method is simple and improves control accuracy and efficiency.

[0097] In some feasible implementations, the reactive power adjustment of the power plant and the active power adjustment of the inverter satisfy the following formula:

[0098] d 2 Q2(u) / du 2 <0 (5)

[0099] d2 P2(f) / df 2 <0 (6)

[0100] Here, Q2(u) is a function of the reactive power adjustment of the power station with respect to the grid voltage amplitude, d 2 Q2(u) / du 2 Let P2(f) be the second derivative of the reactive power adjustment of the power plant with respect to the grid voltage amplitude, and let d be the function of the active power adjustment of the power plant with respect to the grid voltage frequency. 2 P2(f) / df 2 This is the second derivative of the power plant's active power adjustment with respect to the grid-connected voltage frequency.

[0101] It is understandable that in specific application scenarios, the larger the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude, the larger the corresponding reactive power adjustment of the power station. Furthermore, the reactive power adjustment and the grid-connected voltage amplitude are not simply linearly related. When the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude increases, the growth rate of the reactive power adjustment is greater than the growth rate of the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude. Therefore, using Q2(u) (e.g., a quadratic power function) as the fitting function for the reactive power adjustment of the power station with respect to the grid-connected voltage amplitude can prevent the reactive power adjustment from being too small when the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude is large due to an excessively small linear fitting coefficient, and also prevent the reactive power adjustment from being too large when the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude is small due to an excessively large linear fitting coefficient.

[0102] Furthermore, it can be understood that in specific application scenarios, the greater the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency, the greater the corresponding active power adjustment of the power station. Moreover, the active power adjustment of the power station and the grid-connected voltage frequency are not simply linearly related; when the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency increases, the growth rate of the corresponding active power adjustment of the power station is greater than the growth rate of the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency. Please refer to [further details omitted]. Figure 4 , Figure 4 This is a schematic diagram illustrating the relationship between the active power adjustment of a power station and frequency in a power supply system provided in an embodiment of this application. For example... Figure 4 As shown in part (a), the dashed line represents the curve of the power plant's active power adjustment versus the grid connection voltage frequency obtained by fitting a linear function, while the solid line represents the curve of the power plant's active power adjustment versus the grid connection voltage frequency in actual application scenarios. Figure 4In part (a), the linear fitting coefficient shown by the dashed line is too large. When the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency is small, the active power adjustment of the power station is too large. If linear fitting is performed according to the dashed line, the obtained active power adjustment of the power station will have a large error compared to the actual required active power adjustment. Figure 4 As shown in section (b), the dashed line represents the curve of the power plant's active power adjustment versus the grid connection voltage frequency obtained by fitting a linear function, while the solid line represents the curve of the power plant's active power adjustment versus the grid connection voltage frequency in actual application scenarios. Figure 4 In part (b), the linear fitting coefficient shown by the dashed line is too small. When the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency is large, the active power adjustment of the power station is too small. If linear fitting is performed according to the dashed line, the obtained active power adjustment of the power station will have a large error compared to the actual required active power adjustment. Figure 4 As shown in section (c), the dashed line represents the curve of the power plant's active power adjustment versus the grid connection voltage frequency obtained by fitting a linear function, while the solid line represents the curve of the power plant's active power adjustment versus the grid connection voltage frequency in actual application scenarios. Figure 4 In part (c), the linear fitting coefficients shown by the dashed line are moderate, but the active power adjustment obtained by linear fitting according to the dashed line still has a large error compared to the actual required active power adjustment. It is evident that there will always be a significant error between the active power adjustment obtained by linear fitting and the actual required active power adjustment. In this application, as... Figure 4 As shown in section (d), the dashed line represents the curve of the power plant's active power adjustment versus the grid-connected voltage frequency obtained by fitting a nonlinear function, while the solid black line represents the curve of the power plant's active power adjustment versus the grid-connected voltage frequency in the actual application scenario. It can be seen that the curve of the power plant's active power adjustment versus the grid-connected voltage frequency obtained by fitting a nonlinear function has a smaller error than the curve of the power plant's active power adjustment versus the grid-connected voltage frequency in the actual application scenario, thus improving the system's control accuracy.

[0103] Therefore, using P2(f) (e.g., a quadratic power function) as the function of the active power adjustment of the power station with respect to the grid connection voltage frequency can prevent the active power adjustment of the power station from being too small when the difference between the grid connection voltage frequency and the target grid connection voltage frequency is large due to the linear fitting coefficient being too small during linear fitting. It can also prevent the active power adjustment of the power station from being too large when the difference between the grid connection voltage frequency and the target grid connection voltage frequency is small due to the linear fitting coefficient being too large during linear fitting.

[0104] In some feasible implementations, the reactive power adjustment of the power plant and the active power adjustment of the inverter can satisfy the following formula:

[0105] Q2 = k21·(Uc-U2) 2(7)

[0106] P2 = k22·(fc - f2) 2 (8)

[0107] Where Q2 is the reactive power adjustment of the power station, Uc is the target grid-connected voltage amplitude, U2 is the grid-connected voltage amplitude, k21 is the reactive power adjustment coefficient of the power station, P2 is the active power adjustment of the power station, fc is the target grid-connected voltage frequency, f2 is the grid-connected voltage frequency, and k22 is the active power adjustment coefficient of the power station.

[0108] Using the implementation method provided in this application, Q2(u) (e.g., the quadratic power function shown in Formula 7) is used as a function of the reactive power adjustment of the power station with respect to the grid voltage amplitude. This allows for a more accurate determination of the reactive power adjustment based on the grid voltage amplitude, and the method is simple, improving control accuracy and efficiency. Similarly, using P2(f) (e.g., the quadratic power function shown in Formula 8) as a function of the active power adjustment of the power station with respect to the grid voltage frequency allows for a more accurate determination of the active power adjustment based on the grid voltage frequency. This method is simple, and the control accuracy and efficiency are improved.

[0109] In some feasible implementations, the output reactive power adjustment and the output active power adjustment satisfy the following formula:

[0110] Qout=Q1+k1(Q2-Q1) (9)

[0111] Pout = P1 + k2(P2 - P1) (10)

[0112] Here, Qout is the output reactive power adjustment, Q1 is the inverter reactive power adjustment, Q2 is the power plant reactive power adjustment, k1 is the output reactive power adjustment coefficient, Pout is the output active power adjustment, P1 is the inverter active power adjustment, P2 is the power plant active power adjustment, and k2 is the output active power adjustment coefficient.

[0113] Please see again Figure 4 ,like Figure 4 As shown in section (d), the gray solid line represents the curve of the output active power adjustment relative to the grid-connected voltage frequency, obtained simultaneously based on the active power adjustment of the power plant and the active power adjustment of the inverter. The system can simultaneously obtain the curve of the output active power adjustment relative to the grid-connected voltage frequency based on both the power plant and inverter active power adjustments, further reducing the error compared to the actual curve of the power plant active power adjustment relative to the grid-connected voltage frequency in practical applications, and further improving the system's control accuracy.

[0114] Using the implementation method provided in this application, the system can obtain the output reactive power adjustment Qout (i.e., the target reactive power adjustment of the inverter output power) based on the power station reactive power adjustment Q1 and the inverter reactive power adjustment Q1. It can also obtain the output active power adjustment Pout (i.e., the target active power adjustment of the inverter output power) based on the power station useful power adjustment P1 and the inverter active power adjustment P2. Based on the output reactive power adjustment Qout and the output active power adjustment Pout, the system generates an output power adjustment signal (e.g., a pulse width modulation signal or other control signal that can control the inverter output power), thereby improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0115] In some feasible implementations, the power plant power adjustment signal may include the amplitude and frequency of the grid-connected voltage. The power plant acquisition module 204 can also be used to acquire the amplitude and frequency of the grid-connected voltage at the grid connection point and output these values ​​to the inverter acquisition control circuit 200. In scenarios where the communication speed (or frequency) between the power plant acquisition module 204 and the inverter acquisition control circuit 200 is limited, or in other scenarios where real-time communication between the power plant acquisition module 204 and the inverter acquisition control circuit 200 is inconvenient, the power plant acquisition module 204 can acquire the amplitude and frequency of the grid-connected voltage at the grid connection point and output these values ​​to the inverter acquisition control circuit 200, which then determines the power plant power adjustment amount based on the amplitude and frequency of the grid-connected voltage. Using the implementation method provided in this application, the system can output the amplitude and frequency of the grid-connected voltage at the grid connection point to the inverter acquisition control circuit 200 in scenarios where the communication speed (or frequency) between the power plant acquisition module 204 and the inverter acquisition control circuit 200 is limited, or in other scenarios where real-time communication between the power plant acquisition module 204 and the inverter acquisition control circuit 200 is inconvenient. The inverter acquisition control circuit 200 then determines the adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage. The method is simple, flexible, and highly applicable, enriching the applicable scenarios and scope of the system.

[0116] In some feasible implementations, the inverter acquisition control circuit may also include a signal confirmation module. See also... Figure 5 , Figure 5 This is another structural schematic diagram of the power supply system provided in an embodiment of this application. For example... Figure 5As shown, the inverter acquisition and control circuit 300 may further include a signal confirmation module 307. Here, the power supply 301 can be connected to the inverter 302 and the transformer 303, the transformer 303 can be connected to the grid at the grid connection point, one end of the power station acquisition module 304 can be connected to the grid connection point, the other end of the power station acquisition module 304 can be connected to the first end of the inverter acquisition and control circuit 300, the second end of the inverter acquisition and control circuit 300 can be connected between the inverter 302 and the transformer 303, and the third end of the inverter acquisition and control circuit 300 can be connected to the inverter 302. Here, the first terminal of the power adjustment module 306 can be connected to the power station acquisition module 304 as the first terminal of the inverter acquisition control circuit 300. One terminal of the inverter acquisition module 305 can be connected between the inverter 302 and the transformer 303 as the second terminal of the inverter acquisition control circuit 300. The other terminal of the inverter acquisition module 305 can be connected to the second terminal of the power adjustment module 306. The third terminal of the power adjustment module 306 can be connected to the inverter 302 as the third terminal of the inverter acquisition control circuit 300. The first terminal of the power adjustment module 306 can be connected to the power station acquisition module 304 via the signal confirmation module 307. The signal confirmation module 307 can be used to obtain the reactive power adjustment amount of the power station based on the amplitude value of the grid-connected voltage, obtain the active power adjustment amount of the power station based on the frequency of the grid-connected voltage, and output the reactive power adjustment amount and the active power adjustment amount of the power station to the power adjustment module 306. In scenarios where the communication speed (or frequency) between the power plant acquisition module 304 and the inverter acquisition control circuit 300 is limited, or in other scenarios where real-time communication between the power plant acquisition module 304 and the inverter acquisition control circuit 300 is inconvenient, or in other scenarios where the power plant acquisition module 304 directly transmits the amplitude and frequency of the grid-connected voltage to the inverter acquisition control circuit 300, the signal confirmation module 307 can determine the reactive power adjustment amount and active power adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage at the grid connection point, and then output the reactive power adjustment amount and active power adjustment amount of the power plant power as power plant power adjustment signals to the power adjustment module 306 in the inverter acquisition circuit. Therefore, the power adjustment module 306 can obtain the target reactive power adjustment amount of the inverter 302 output power based on the combined reactive power adjustment amount of the power station and the inverter reactive power adjustment amount. It can also obtain the target active power adjustment amount of the inverter 302 output power based on the combined useful power adjustment amount of the power station and the active power adjustment amount of the inverter. Furthermore, it can control the inverter 302 to output the target output power (here, the target output power can include both target reactive power and target active power), resulting in a simple structure. In addition, the inverter 302 can be controlled to output the target reactive power and / or target active power separately, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0117] Using the implementation method provided in this application, in scenarios where the communication speed (or frequency) between the power plant acquisition module 304 and the inverter acquisition control circuit 300 is limited, or in other scenarios where real-time communication between the power plant acquisition module 304 and the inverter acquisition control circuit 300 is inconvenient, or in other scenarios where the power plant acquisition module 304 directly transmits the amplitude and frequency of the grid-connected voltage to the inverter acquisition control circuit 300, the signal confirmation module 307 can determine the reactive power adjustment amount and active power adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage at the grid connection point, and then output the reactive power adjustment amount and active power adjustment amount of the power plant power as power plant power adjustment signals to the power adjustment module 306 in the inverter acquisition circuit. The method is simple, flexible, and highly applicable, enriching the applicable scenarios and scope of the system. The power adjustment module 306 can obtain the target reactive power adjustment amount of the inverter 302 output power based on the combined reactive power adjustment amount of the power station and the inverter reactive power adjustment amount. It can also obtain the target active power adjustment amount of the inverter 302 output power based on the combined useful power adjustment amount of the power station and the active power adjustment amount of the inverter. Furthermore, it can control the inverter 302 to output the target output power (here, the target output power can include both target reactive power and target active power), resulting in a simple structure. In addition, the system can separately control the inverter 302 to output the target reactive power and / or target active power, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0118] In some feasible implementations, the power adjustment module may further include an adjustment amount confirmation unit and a power control unit. See also... Figure 6 , Figure 6 This is another structural schematic diagram of the power supply system provided in an embodiment of this application. For example... Figure 6As shown, the power adjustment module 406 may further include an adjustment amount confirmation unit 4061 and a power control unit 4062. Here, the power supply 401 can be connected to the inverter 402 and the transformer 403. The transformer 403 can be connected to the grid at the grid connection point. One end of the power station acquisition module 404 can be connected to the grid connection point, and the other end of the power station acquisition module 404 can be connected to the first end of the inverter acquisition control circuit 400. The second end of the inverter acquisition control circuit 400 can be connected between the inverter 402 and the transformer 403, and the third end of the inverter acquisition control circuit 400 can be connected to the inverter 402. Here, the first terminal of the power adjustment module 406 can be connected to the power station acquisition module 404 as the first terminal of the inverter acquisition control circuit 400. One terminal of the inverter acquisition module 405 can be connected between the inverter 402 and the transformer 403 as the second terminal of the inverter acquisition control circuit 400. The other terminal of the inverter acquisition module 405 can be connected to the second terminal of the power adjustment module 406. The third terminal of the power adjustment module 406 can be connected to the inverter 402 as the third terminal of the inverter acquisition control circuit 400. Here, the first terminal of the power adjustment module 406 can be connected to the power station acquisition module 404 through the signal confirmation module 407. Here, the power control unit 4062 is connected to the inverter 402 and one terminal of the adjustment amount confirmation unit 4061. The other terminal of the adjustment amount confirmation unit 4061 is connected to the inverter acquisition module 405, or the other terminal of the adjustment amount confirmation unit 4061 is connected to the signal confirmation module 407. The adjustment confirmation unit 4061 here can be used to obtain the output reactive power adjustment based on the power station reactive power adjustment and the inverter reactive power adjustment, obtain the output active power adjustment based on the power station active power adjustment and the inverter active power adjustment, and generate an output power adjustment signal based on the output reactive power adjustment and the output active power adjustment. The power control unit 4062 here can be used to control the inverter 402 to output the target output power through the output power adjustment signal. Here, the adjustment confirmation unit 4061 (e.g., a proportional-integral amplifier circuit) can obtain the output reactive power adjustment (i.e., the target reactive power adjustment of the inverter 402's output power) based on the power station reactive power adjustment and the inverter reactive power adjustment, and can also obtain the output active power adjustment (i.e., the target active power adjustment of the inverter 402's output power) based on the power station useful power adjustment and the inverter active power adjustment. It then generates an output power adjustment signal (e.g., a pulse-width modulation signal or other control signal that can control the output power of the inverter 402) based on the output reactive power adjustment and the output active power adjustment. Here, the power control unit 4062 can control the inverter 402 to output the target output power (where the target output power may include the target reactive power and the target active power) through the output power adjustment signal, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0119] In some feasible implementations, the power supply system may also include a DC bus, through which the power supply 501 can be connected to the power grid via the DC bus, inverter 502, and transformer 503. Here, the DC bus may include a single bus capacitor or multiple bus capacitors connected in series for energy storage. The DC bus may include a bus capacitor C, and the inverter 502 can convert the electrical energy output from the power supply 501 and stored across the bus capacitor C, and output corresponding current and voltage to maintain the operation of the power grid.

[0120] Please see also Figure 7 , Figure 7 This is another structural schematic diagram of the power supply system provided in an embodiment of this application. Figure 7 The power supply system shown may also include a combiner box 508, through which the power supply 501 can be connected to the inverter 502. It can be understood that the power supply 501 in the power supply system can be connected to the combiner box 508 and then directly connected to the inverter 502, or it can be connected to the DC bus through the combiner box 508 and then connected to the inverter 502. The specific configuration can be determined according to the actual application scenario and is not limited here. Figure 7 The connection method and working principle of the power supply 501, inverter 502, transformer 503, inverter acquisition and control circuit 500 (including inverter acquisition module 505, power adjustment module 506 (including adjustment amount confirmation unit 5061 and power control unit 5062), power station acquisition module 504, inverter acquisition module 505 and signal confirmation module 507 are the same as those described above. Figure 6 The connection method and working principle of the power supply 401, inverter 402, transformer 403, inverter acquisition and control circuit 400 (including inverter acquisition module 405, power adjustment module 406 (including adjustment amount confirmation unit 4061 and power control unit 4062), power station acquisition module 404, inverter acquisition module 405 and signal confirmation module 407 are the same, and will not be described again here.

[0121] See Figure 8 , Figure 8 This is another structural schematic diagram of the power supply system provided in an embodiment of this application. For example... Figure 8 As shown, the power supply system may also include a grid connection device 609. The power supply 601 can supply power to power lines, power transfer stations, batteries, communication base stations, or household appliances and other electrical equipment in the power grid through the inverter 602, transformer 603, and grid connection device 609. Figure 8The connection methods and working principles of the power supply 601, inverter 602, transformer 603, inverter acquisition and control circuit 600 (including inverter acquisition module 605, power adjustment module 606 (including adjustment amount confirmation unit 6061 and power control unit 6062), power station acquisition module 604, inverter acquisition module 605, signal confirmation module 607, and combiner box 608 are the same as those described above. Figure 7 The connection method and working principle of the power supply 501, inverter 502, transformer 503, inverter acquisition and control circuit 500 (including inverter acquisition module 505, power adjustment module 506 (including adjustment amount confirmation unit 5061 and power control unit 5062), power station acquisition module 504, inverter acquisition module 505, signal confirmation module 507 and combiner box 508 are the same, and will not be described again here.

[0122] In this application, the functional modules of the power supply system are arranged in a variety of flexible ways to adapt to different power supply environments, thereby increasing the diversity of application scenarios and enhancing the adaptability of the power supply system. Meanwhile, in the aforementioned... Figures 1 to 8 In any of the power supply systems shown (or the power station acquisition module connected to the grid connection point in the power supply system and the inverter acquisition and control circuit of the power supply system), the power supply system (or the power station acquisition module connected to the grid connection point in the power supply system and the inverter acquisition and control circuit of the power supply system) can provide harmonic current to nonlinear loads through the inverter in the power supply system, thereby improving the sinusoidal nature of the grid connection point current, improving the power quality of the power supply system, extending the service life of components, and reducing costs. For ease of description, the following will use... Figure 2 The structure of the power supply system shown is used to illustrate the power supply method of the power supply system provided in the embodiments of this application.

[0123] Please see Figure 9 , Figure 9 This is a flowchart illustrating the grid connection control method provided in this application. The grid connection control method provided in this application is applicable to the above-mentioned... Figures 1 to 8 Any of the power supply systems shown. For example... Figure 9 As shown, the grid connection control method provided in this application includes the following steps:

[0124] S701: The power plant acquisition module obtains the amplitude and frequency of the grid-connected voltage at the grid connection point, and obtains the power plant power adjustment signal based on the amplitude and frequency of the grid-connected voltage.

[0125] S702: The inverter acquisition and control circuit acquires the amplitude and frequency of the inverter's output voltage, obtains the inverter power adjustment signal based on the amplitude and frequency of the output voltage, and controls the inverter to output the target output power based on the power station power adjustment signal and the inverter power adjustment signal.

[0126] In the embodiments provided in this application, the power plant acquisition module can acquire the amplitude and frequency of the grid-connected voltage at the grid connection point. Here, the amplitude and frequency of the grid-connected voltage are related to the power plant power (i.e., the power output by the power supply system at the grid connection point). The system can determine the adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage, thereby obtaining a power plant power adjustment signal. The inverter acquisition and control circuit can acquire the amplitude and frequency of the inverter's output voltage. Here, the amplitude and frequency of the inverter's output voltage are related to the inverter power (i.e., the power output by the inverter). The inverter acquisition and control circuit can determine the adjustment amount of the inverter power based on the amplitude and frequency of the inverter's output voltage, thereby obtaining an inverter power adjustment signal. Since there are other functional modules or power components (e.g., transformers) between the inverter's output terminal and the grid connection point, the inverter acquisition and control circuit can obtain the target adjustment amount of the inverter's output power based on the combined power plant power adjustment signal and the inverter power adjustment signal, and can control the inverter to output the target output power.

[0127] Using the implementation method provided in this application, the system can acquire the amplitude and frequency of the grid-connected voltage at the grid connection point and the output voltage of the inverter through the power station acquisition module and the inverter acquisition control circuit, and determine the power station power adjustment signal and the inverter power adjustment signal respectively. Then, the output power of the inverter is adjusted based on the power station power adjustment signal and the inverter power adjustment signal. The structure is simple, the control method is convenient, the control accuracy and regulation efficiency are improved, the control time is reduced, and the control cost is reduced.

[0128] In some feasible implementations, the power plant power adjustment signal may include reactive power adjustment and active power adjustment. See also... Figure 10 , Figure 10 This is another flowchart illustrating the grid connection control method provided in this application. For example... Figure 10 As shown, obtaining the power plant power adjustment signal based on the amplitude and frequency of the grid-connected voltage in the aforementioned step S701 may include:

[0129] S801: The power station acquisition module obtains the reactive power adjustment amount of the power station based on the amplitude value of the grid-connected voltage, and obtains the active power adjustment amount of the power station based on the frequency of the grid-connected voltage, and outputs the reactive power adjustment amount and the active power adjustment amount of the power station to the inverter acquisition and control circuit.

[0130] It is understandable that after the power plant acquisition module obtains the amplitude and frequency of the grid-connected voltage, since the amplitude of the grid-connected voltage is non-linearly related to the reactive power adjustment in the power plant power (i.e., the power output by the power supply system at the grid connection point), and the frequency of the grid-connected voltage is non-linearly related to the active power adjustment in the power plant power (i.e., the power output by the power supply system at the grid connection point), the power plant acquisition module can determine the reactive power adjustment and active power adjustment of the power plant power based on the amplitude and frequency of the grid-connected voltage at the grid connection point, and then output the reactive power adjustment and active power adjustment of the power plant power to the inverter acquisition circuit. Using the implementation method provided in this application, the power plant acquisition module can determine the reactive power adjustment and active power adjustment of the power plant power based on the amplitude and frequency of the grid-connected voltage at the grid connection point, and then output the reactive power adjustment and active power adjustment of the power plant power as power plant power adjustment signals to the power adjustment module in the inverter acquisition circuit. Therefore, the power adjustment module can obtain the target reactive power adjustment of the inverter output power based on the reactive power adjustment of the power station and the reactive power adjustment of the inverter. It can also obtain the target active power adjustment of the inverter output power based on the useful power adjustment of the power station and the active power adjustment of the inverter. Furthermore, it can control the inverter to output the target output power (here, the target output power can include both target reactive power and target active power), resulting in a simple structure. In addition, the system can separately control the inverter to output the target reactive power and / or target active power, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0131] In some feasible implementations, the inverter acquisition and control circuit in step S702 acquires the amplitude and frequency of the output voltage at the inverter output terminal, obtains the inverter power adjustment signal based on the amplitude and frequency of the output voltage, and controls the output power of the inverter to the target output power based on the power station power adjustment signal and the inverter power adjustment signal. This may include the following steps:

[0132] S802: Obtain the amplitude and frequency of the inverter's output voltage, obtain the inverter reactive power adjustment based on the amplitude of the output voltage, obtain the inverter active power adjustment based on the frequency of the output voltage, and obtain the inverter power adjustment signal based on the inverter reactive power adjustment and the inverter active power adjustment.

[0133] S803: Generates an output power adjustment signal based on the power station power adjustment signal and the inverter power adjustment signal, and controls the output power of the inverter to the target output power through the output power adjustment signal.

[0134] It can be understood that after acquiring the amplitude and frequency of the inverter's output voltage, since the amplitude of the inverter's output voltage is non-linearly related to the reactive power adjustment in the inverter power (i.e., the power output by the inverter), and the frequency of the inverter's output voltage is non-linearly related to the active power adjustment in the inverter power (i.e., the power output by the inverter), the inverter acquisition and control circuit can determine the reactive power adjustment and active power adjustment of the inverter power based on the amplitude and frequency of the inverter's output voltage, thereby obtaining the inverter power adjustment signal. Furthermore, it can be understood that the inverter acquisition and control circuit can jointly obtain the target adjustment amount of the inverter's output power based on the power station power adjustment signal output by the power station acquisition module and the inverter power adjustment signal output by the inverter acquisition and control circuit, and can control the inverter to output the target output power.

[0135] Using the implementation method provided in this application, the inverter acquisition and control circuit can determine the reactive power adjustment amount and active power adjustment amount of the inverter power based on the amplitude value and frequency of the inverter's output voltage, thereby obtaining the inverter power adjustment signal. Then, based on the power adjustment signal output by the power station acquisition module and the inverter power adjustment signal output by the inverter acquisition and control circuit, the target adjustment amount of the inverter output power can be obtained, and the inverter can be controlled to output the target output power. The structure is simple. Furthermore, the inverter acquisition and control circuit can control the reactive power and active power of the inverter separately, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0136] In some feasible implementations, the inverter reactive power adjustment and the inverter active power adjustment satisfy the following formula:

[0137] d 2 Q1(u) / du 2 <0 (11)

[0138] d 2 P1(f) / df 2 <0 (12)

[0139] Here, Q1(u) is a function of the inverter reactive power adjustment with respect to the output voltage amplitude, d 2 Q1(u) / du 2 Let P1(f) be the second derivative of the inverter reactive power adjustment with respect to the output voltage amplitude, and let d be the function of the inverter active power adjustment with respect to the output voltage frequency. 2 P1(f) / df 2 It is the second derivative of the inverter active power adjustment with respect to the output voltage frequency.

[0140] It is understandable that in specific application scenarios, the larger the difference between the output voltage amplitude and the target output voltage amplitude, the larger the corresponding inverter reactive power adjustment. Furthermore, the inverter reactive power adjustment and the output voltage amplitude are not simply linearly related. When the difference between the output voltage amplitude and the target output voltage amplitude increases, the growth rate of the corresponding inverter reactive power adjustment is greater than the growth rate of the difference between the output voltage amplitude and the target output voltage amplitude. Therefore, using Q1(u) (e.g., a quadratic power function) as the fitting function for the inverter reactive power adjustment with respect to the output voltage amplitude can prevent the inverter reactive power adjustment from being too small when the difference between the output voltage amplitude and the target output voltage amplitude is large due to an excessively small linear fitting coefficient, and also prevent the inverter reactive power adjustment from being too large when the difference between the output voltage amplitude and the target output voltage amplitude is small due to an excessively large linear fitting coefficient.

[0141] Furthermore, in specific application scenarios, the larger the difference between the output voltage frequency and the target output voltage frequency, the larger the corresponding inverter active power adjustment. Moreover, the inverter active power adjustment and the output voltage frequency are not simply linearly related. When the difference between the output voltage frequency and the target output voltage frequency increases, the growth rate of the corresponding inverter active power adjustment is greater than the growth rate of the difference between the output voltage frequency and the target output voltage frequency. Therefore, using P1(f) (e.g., a quadratic function) as the function of the inverter active power adjustment with respect to the output voltage frequency can prevent the inverter active power adjustment from being too small when the difference between the output voltage frequency and the target output voltage frequency is large due to an excessively small linear fitting coefficient during linear fitting, and also prevent the inverter active power adjustment from being too large when the difference between the output voltage frequency and the target output voltage frequency is small due to an excessively large linear fitting coefficient.

[0142] Using the implementation method provided in this application, Q1(u) (e.g., a power function) is used as a function of the inverter reactive power adjustment amount with respect to the output voltage amplitude value. This allows for a more accurate determination of the inverter reactive power adjustment amount based on the output voltage amplitude value. The method is simple and improves control accuracy and efficiency. Similarly, using P1(f) (e.g., a power function) as a function of the inverter active power adjustment amount with respect to the output voltage frequency allows for a more accurate determination of the inverter active power adjustment amount based on the output voltage frequency. This method is simple and improves control accuracy and efficiency.

[0143] In some feasible implementations, the reactive power adjustment of the power plant and the active power adjustment of the inverter satisfy the following formula:

[0144] d 2 Q2(u) / du 2 <0 (13)

[0145] d 2 P2(f) / df 2 <0 (14)

[0146] Here, Q2(u) is a function of the reactive power adjustment of the power station with respect to the grid voltage amplitude, d 2 Q2(u) / du 2 Let P2(f) be the second derivative of the reactive power adjustment of the power plant with respect to the grid voltage amplitude, and let d be the function of the active power adjustment of the power plant with respect to the grid voltage frequency. 2 P2(f) / df 2 This is the second derivative of the power plant's active power adjustment with respect to the grid-connected voltage frequency.

[0147] It is understandable that in specific application scenarios, the larger the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude, the larger the corresponding reactive power adjustment of the power station. Furthermore, the reactive power adjustment and the grid-connected voltage amplitude are not simply linearly related. When the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude increases, the growth rate of the reactive power adjustment is greater than the growth rate of the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude. Therefore, using Q2(u) (e.g., a quadratic power function) as the fitting function for the reactive power adjustment of the power station with respect to the grid-connected voltage amplitude can prevent the reactive power adjustment from being too small when the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude is large due to an excessively small linear fitting coefficient, and also prevent the reactive power adjustment from being too large when the difference between the grid-connected voltage amplitude and the target grid-connected voltage amplitude is small due to an excessively large linear fitting coefficient.

[0148] Furthermore, it can be understood that in specific application scenarios, the larger the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency, the larger the corresponding active power adjustment of the power station. Moreover, the active power adjustment of the power station and the grid-connected voltage frequency are not simply linearly related. When the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency increases, the growth rate of the corresponding active power adjustment of the power station is greater than the growth rate of the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency. Therefore, using P2(f) (e.g., a quadratic power function) as the function of the active power adjustment of the power station with respect to the grid-connected voltage frequency can prevent the active power adjustment from being too small when the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency is large due to an excessively small linear fitting coefficient, and also prevent the active power adjustment from being too large when the difference between the grid-connected voltage frequency and the target grid-connected voltage frequency is small due to an excessively large linear fitting coefficient.

[0149] Using the implementation method provided in this application, Q2(u) (e.g., a power function) is used as a function of the reactive power adjustment of the power station with respect to the grid voltage amplitude. This allows for a more accurate determination of the reactive power adjustment based on the grid voltage amplitude, and the method is simple, improving control accuracy and efficiency. Similarly, using P2(f) (e.g., a power function) as a function of the active power adjustment of the power station with respect to the grid voltage frequency allows for a more accurate determination of the active power adjustment based on the grid voltage frequency. This method is simple, and the control accuracy and efficiency are also improved.

[0150] In some feasible implementations, the output reactive power adjustment and the output active power adjustment satisfy the following formula:

[0151] Qout=Q1+k1(Q2-Q1) (15)

[0152] Pout = P1 + k2(P2 - P1) (16)

[0153] Here, Qout is the output reactive power adjustment, Q1 is the inverter reactive power adjustment, Q2 is the power plant reactive power adjustment, k1 is the output reactive power adjustment coefficient, Pout is the output active power adjustment, P1 is the inverter active power adjustment, P2 is the power plant active power adjustment, and k2 is the output active power adjustment coefficient.

[0154] Using the implementation method provided in this application, the system can obtain the output reactive power adjustment Qout (i.e., the target reactive power adjustment of the inverter output power) based on the power station reactive power adjustment Q1 and the inverter reactive power adjustment Q1. It can also obtain the output active power adjustment Pout (i.e., the target active power adjustment of the inverter output power) based on the power station useful power adjustment P1 and the inverter active power adjustment P2. Based on the output reactive power adjustment Qout and the output active power adjustment Pout, the system generates an output power adjustment signal (e.g., a pulse width modulation signal or other control signal that can control the inverter output power), thereby improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0155] In some feasible implementations, the power plant power adjustment signal may include the amplitude and frequency of the grid-connected voltage. The step S701 described above, which obtains the power plant power adjustment signal based on the amplitude and frequency of the grid-connected voltage, may include: the power plant acquisition module acquiring the amplitude and frequency of the grid-connected voltage at the grid connection point, and outputting the amplitude and frequency of the grid-connected voltage at the grid connection point to the inverter acquisition and control circuit.

[0156] Using the implementation method provided in this application, the system can output the amplitude and frequency of the grid-connected voltage at the grid connection point to the inverter acquisition control circuit through the inverter acquisition control circuit in scenarios where the communication speed (or frequency) between the power plant acquisition module and the inverter acquisition control circuit is limited, or in other scenarios where real-time communication between the power plant acquisition module and the inverter acquisition control circuit is inconvenient. The inverter acquisition control circuit then determines the adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage. The method is simple, flexible, and highly applicable, enriching the applicable scenarios and scope of the system.

[0157] In some feasible implementations, after outputting the amplitude and frequency of the grid-connected voltage at the grid connection point to the inverter acquisition and control circuit in step S701, the method may include:

[0158] The reactive power adjustment of the power station is obtained based on the amplitude of the grid-connected voltage, and the active power adjustment is obtained based on the frequency of the grid-connected voltage. Both the reactive power adjustment and active power adjustment are then output. In scenarios where the communication speed (or frequency) between the power station acquisition module and the inverter acquisition control circuit is limited, or in other scenarios where real-time communication between the power station acquisition module and the inverter acquisition control circuit is inconvenient, or in scenarios where the power station acquisition module directly transmits the amplitude and frequency of the grid-connected voltage to the inverter acquisition control circuit, the inverter acquisition control circuit can determine the reactive power adjustment and active power adjustment of the power station based on the amplitude and frequency of the grid-connected voltage at the grid connection point, respectively. Then, the reactive power adjustment and active power adjustment of the power station are output as power adjustment signals. Therefore, the inverter acquisition and control circuit can obtain the target reactive power adjustment of the inverter output power based on the combined reactive power adjustment of the power station and the inverter, and can also obtain the target active power adjustment of the inverter output power based on the combined useful power adjustment of the power station and the active power adjustment of the inverter. Furthermore, it can control the inverter to output the target output power (here, the target output power can include both target reactive power and target active power), resulting in a simple structure. In addition, the inverter acquisition and control circuit can separately control the inverter to output the target reactive power and / or target active power, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0159] Using the implementation method provided in this application, in scenarios where the communication speed (or frequency) between the power plant acquisition module and the inverter acquisition control circuit is limited, or in other scenarios where real-time communication between the power plant acquisition module and the inverter acquisition control circuit is inconvenient, or in other scenarios where the power plant acquisition module directly transmits the amplitude and frequency of the grid-connected voltage to the inverter acquisition control circuit, the inverter acquisition control circuit can determine the reactive power adjustment amount and active power adjustment amount of the power plant power based on the amplitude and frequency of the grid-connected voltage at the grid connection point, and then output the reactive power adjustment amount and active power adjustment amount of the power plant power as power plant power adjustment signals. The method is simple, flexible, and highly applicable, enriching the applicable scenarios and scope of the system. The inverter acquisition control circuit can obtain the target reactive power adjustment amount of the inverter output power based on the combined reactive power adjustment amount of the power plant and the inverter reactive power adjustment amount, and can also obtain the target active power adjustment amount of the inverter output power based on the combined active power adjustment amount of the power plant and the inverter active power adjustment amount, and can control the inverter to output the target output power (here, the target output power may include the target reactive power and the target active power), with a simple structure. In addition, the inverter acquisition and control circuit can control the inverter output target reactive power and / or target active power separately, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0160] In some feasible implementations, the power adjustment module in step S702 generates an output power adjustment signal based on the power plant power adjustment signal and the inverter power adjustment signal, and controls the inverter's output power to the target output power through the output power adjustment signal. This may include: obtaining the output reactive power adjustment amount based on the power plant reactive power adjustment amount and the inverter reactive power adjustment amount; obtaining the output active power adjustment amount based on the power plant active power adjustment amount and the inverter active power adjustment amount; and generating the output power adjustment signal based on the output reactive power adjustment amount and the output active power adjustment amount. The inverter is then controlled to output the target output power through the output power adjustment signal.

[0161] Here, the inverter acquisition and control circuit can obtain the output reactive power adjustment (i.e., the target reactive power adjustment of the inverter output power) based on the reactive power adjustment of the power station and the reactive power adjustment of the inverter. It can also obtain the output active power adjustment (i.e., the target active power adjustment of the inverter output power) based on the useful power adjustment of the power station and the active power adjustment of the inverter. Based on the output reactive power adjustment and the output active power adjustment, it generates an output power adjustment signal (e.g., a pulse width modulation signal or other control signal that can control the inverter output power). Here, the inverter acquisition and control circuit can control the inverter to output the target output power (where the target output power can include both target reactive power and target active power) through the output power adjustment signal, improving control accuracy and regulation efficiency, reducing control time, and lowering control costs.

[0162] In this application, the system can acquire the grid connection voltage at the grid connection point and the amplitude and frequency of the inverter's output voltage through the power station acquisition module and the inverter acquisition control circuit, and determine the power station power adjustment signal and the inverter power adjustment signal respectively. Then, the output power of the inverter is adjusted based on the power station power adjustment signal and the inverter power adjustment signal. The system has a simple structure, a convenient control method, improves control accuracy and regulation efficiency, reduces control time, and lowers control costs.

[0163] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A power supply system, characterized in that, The power supply system includes a power supply, an inverter, a transformer, a power station acquisition module, and an inverter acquisition control circuit. The inverter acquisition control circuit includes an inverter acquisition module and a power adjustment module. The power supply is connected to the inverter and the transformer. The transformer is connected to the grid at the grid connection point. One end of the power station acquisition module is connected to the grid connection point. The other end of the power station acquisition module is connected to the first end of the inverter acquisition control circuit. The second end of the inverter acquisition control circuit is connected between the inverter and the transformer. The third end of the inverter acquisition control circuit is connected to the inverter. The first end of the power adjustment module serves as the first end of the inverter acquisition control circuit and is connected to the power station acquisition module. One end of the inverter acquisition module serves as the second end of the inverter acquisition control circuit and is connected between the inverter and the transformer. The other end of the inverter acquisition module is connected to the second end of the power adjustment module. The third end of the power adjustment module serves as the third end of the inverter acquisition control circuit and is connected to the inverter. The power plant acquisition module is used to acquire the amplitude and frequency of the grid connection voltage at the grid connection point, and to obtain the power plant power adjustment signal based on the amplitude and frequency of the grid connection voltage. The inverter acquisition module is used to acquire the amplitude and frequency of the inverter's output voltage, obtain the inverter reactive power adjustment amount based on the amplitude of the output voltage, obtain the inverter active power adjustment amount based on the frequency of the output voltage, and obtain the inverter power adjustment signal based on the inverter reactive power adjustment amount and the inverter active power adjustment amount. The power adjustment module is used to generate an output power adjustment signal based on the power adjustment signal of the power plant and the inverter power adjustment signal, and to control the inverter to output the target output power through the output power adjustment signal.

2. The power supply system according to claim 1, characterized in that, The power adjustment signal of the power station includes the reactive power adjustment amount and the active power adjustment amount of the power station. The power station acquisition module is also used to obtain the reactive power adjustment amount of the power station based on the amplitude value of the grid-connected voltage, obtain the active power adjustment amount of the power station based on the frequency of the grid-connected voltage, and output the reactive power adjustment amount and the active power adjustment amount of the power station to the inverter acquisition and control circuit.

3. The power supply system according to claim 1, characterized in that, The power plant power adjustment signal includes the amplitude and frequency of the grid-connected voltage; The power plant acquisition module is also used to acquire the amplitude and frequency of the grid-connected voltage at the grid connection point, and output the amplitude and frequency of the grid-connected voltage at the grid connection point to the inverter acquisition and control circuit.

4. The power supply system according to claim 3, characterized in that, The inverter acquisition and control circuit also includes a signal confirmation module, and the first end of the power adjustment module is connected to the power station acquisition module through the signal confirmation module. The signal confirmation module is used to obtain the reactive power adjustment amount of the power station based on the amplitude value of the grid-connected voltage, obtain the active power adjustment amount of the power station based on the frequency of the grid-connected voltage, and output the reactive power adjustment amount and the active power adjustment amount of the power station to the power adjustment module.

5. The power supply system according to claim 4, characterized in that, The power adjustment module further includes an adjustment amount confirmation unit and a power control unit. The power control unit is connected to the inverter and one end of the adjustment amount confirmation unit, and the other end of the adjustment amount confirmation unit is connected to the inverter acquisition module, or the other end of the adjustment amount confirmation unit is connected to the signal confirmation module. The adjustment confirmation unit is used to obtain the output reactive power adjustment amount based on the power station reactive power adjustment amount and the inverter reactive power adjustment amount, obtain the output active power adjustment amount based on the power station active power adjustment amount and the inverter active power adjustment amount, and generate the output power adjustment signal based on the output reactive power adjustment amount and the output active power adjustment amount. The power control unit is used to control the inverter to output the target output power through the output power adjustment signal.

6. The power supply system according to claim 5, characterized in that, The inverter reactive power adjustment and the inverter active power adjustment satisfy the following: in, The inverter reactive power adjustment is a function of the output voltage amplitude. The second derivative of the inverter reactive power adjustment with respect to the output voltage amplitude is given by the given value. The inverter active power adjustment is a function of the output voltage frequency. It is the second derivative of the inverter active power adjustment with respect to the output voltage frequency.

7. The power supply system according to claim 6, characterized in that, The reactive power adjustment of the power station and the active power adjustment of the inverter satisfy the following: in, The reactive power adjustment of the power station is a function of the grid-connected voltage amplitude. The second derivative of the reactive power adjustment of the power station with respect to the grid voltage amplitude is given by the second derivative of the reactive power adjustment of the power station. The active power adjustment of the power station is a function of the grid-connected voltage frequency. It is the second derivative of the active power adjustment of the power station with respect to the grid-connected voltage frequency.

8. The power supply system according to claim 7, characterized in that, The output reactive power adjustment and the output active power adjustment satisfy the following: Wherein, Qout is the output reactive power adjustment amount, Q1 is the inverter reactive power adjustment amount, Q2 is the power station reactive power adjustment amount, k1 is the output reactive power adjustment coefficient, Pout is the output active power adjustment amount, P1 is the inverter active power adjustment amount, P2 is the power station active power adjustment amount, and k2 is the output active power adjustment coefficient.

9. The power supply system according to claim 8, characterized in that, The power supply system also includes a combiner box, through which the power supply is connected to the inverter. The power supply system also includes a DC bus, through which the power supply is connected to the DC bus and the DC bus is connected to the inverter. The power supply system also includes a grid connection device, through which the transformer is connected to the power grid.

10. A grid-connected control method, characterized in that, The grid-connected control method is applicable to the power plant acquisition module connected to the grid connection point in the power supply system and the inverter acquisition and control circuit of the power supply system. The method includes: The power plant acquisition module obtains the amplitude and frequency of the grid connection voltage at the grid connection point, and obtains the power plant power adjustment signal based on the amplitude and frequency of the grid connection voltage. The inverter acquisition and control circuit acquires the amplitude and frequency of the inverter's output voltage, obtains the inverter reactive power adjustment based on the amplitude of the output voltage, obtains the inverter active power adjustment based on the frequency of the output voltage, and obtains an inverter power adjustment signal based on the inverter reactive power adjustment and the inverter active power adjustment. Based on the power adjustment signal of the power plant and the inverter power adjustment signal, an output power adjustment signal is generated, and the output power of the inverter is controlled to the target output power through the output power adjustment signal.

11. The grid-connected control method according to claim 10, characterized in that, The power plant power adjustment signal includes reactive power adjustment and active power adjustment. The process of obtaining the power plant power adjustment signal based on the amplitude and frequency of the grid-connected voltage includes: The power station acquisition module obtains the reactive power adjustment amount of the power station based on the amplitude value of the grid-connected voltage, and obtains the active power adjustment amount of the power station based on the frequency of the grid-connected voltage, and outputs the reactive power adjustment amount and the active power adjustment amount of the power station to the inverter acquisition and control circuit.

12. The grid-connected control method according to claim 10, characterized in that, The power plant power adjustment signal includes the amplitude and frequency of the grid-connected voltage, and obtaining the power plant power adjustment signal based on the amplitude and frequency of the grid-connected voltage includes: The power plant acquisition module obtains the amplitude and frequency of the grid-connected voltage at the grid connection point and outputs the amplitude and frequency of the grid-connected voltage at the grid connection point to the inverter acquisition and control circuit.

13. The grid-connected control method according to claim 12, characterized in that, After outputting the amplitude and frequency of the grid-connected voltage at the grid connection point to the inverter acquisition and control circuit, the method includes: The reactive power adjustment of the power station is obtained based on the amplitude value of the grid-connected voltage, and the active power adjustment of the power station is obtained based on the frequency of the grid-connected voltage. The reactive power adjustment and the active power adjustment of the power station are then output.

Images