Voltage control method and system for island distribution station area containing fixed-frequency energy storage converter

Abstract

The present invention belongs to the technical field of station area voltage control, and discloses a method and system for controlling the voltage of an isolated distribution station area containing a fixed-frequency energy storage converter, including collecting and processing signals; calculating the effective value of the phase voltage according to the processed signals, and obtaining the output current effective value instruction of the energy storage converter according to the relationship curve between the current signal output by the energy storage converter and the effective value of the phase voltage; obtaining the control mode of the energy storage converter according to the calculated range of the effective value of the phase voltage, and obtaining the output current effective value instruction of the energy storage converter when the load fluctuates by changing the relationship curve between the output current signal of the energy storage converter and the effective value of the phase voltage; and performing closed-loop control on the output current or port voltage of the energy storage converter according to the above parameters. The present invention can be well compatible with the control strategies of existing wind turbines and photovoltaic inverters, and can still maintain the voltage performance and ensure the balance of output power between energy storage converters when the energy storage converter is bidirectionally charged and discharged.

Description

Technical Field

[0001] The present invention relates to the technical field of transformer area voltage control, and in particular to a method and system for controlling transformer area voltage of an isolated island distribution station including a fixed-frequency energy storage converter. Background Art

[0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] With the increasing penetration of distributed power sources and energy storage devices in distribution networks, it is easier for distribution networks to achieve local power balance. When the main power grid is out of service, the distribution network can restore power to local loads in the form of planned islands / microgrids at any time, which is of great significance for resisting the damage caused by natural disasters and wars and improving power supply reliability.

[0004] The power storage converter (PCS) is the core equipment in the power storage system, responsible for realizing the bidirectional energy conversion between the battery system and the power grid, which can effectively smooth the volatility of new energy such as wind and solar power and realize reliable power supply to the load. The island system with a high proportion of new energy and a high proportion of power electronic devices has a low inertia and no longer has the electromechanical characteristics of traditional synchronous machines. The traditional control technology based on the dominant mode of synchronous machines-phase synchronization is prone to power-angle stability and frequency stability problems, difficult to plug and play, complex to realize the interconnection control of multiple stations, and prone to transient current shocks.

[0005] To solve the above problems, existing literature adopts satellite timing synchronization signals and proposes a synchronous fixed-frequency converter based on current amplitude-phase voltage effective value droop control. The patent application number is: 2022111962156, and the name is: A Chinese invention patent for a source-load-storage collaborative autonomy method for a distribution station area based on satellite timing synchronization. A source-load-storage collaborative autonomy method for a distribution station area based on satellite timing synchronization is proposed. However, since the installed wind turbines and photovoltaic converters are difficult to transform, the above scheme is difficult to directly apply to existing distribution stations with a high proportion of new energy. For the parallel operation of multiple energy storage converters using fixed-frequency control, the existing current-voltage droop control has the disadvantage of being difficult to take into account voltage deviation and power sharing. The voltage performance of the energy storage converter during bidirectional charging and discharging is not considered, especially when the photovoltaic and load powers are close to equilibrium, it is difficult to achieve stable regulation of the output current command of the energy storage converter. Summary of the invention

[0006] In order to solve the above problems, the present invention proposes a voltage control method and system for an isolated distribution station area containing a fixed-frequency energy storage inverter, which can be well compatible with the control strategies of existing wind turbines and photovoltaic inverters, and can maintain voltage performance and ensure load balance during bidirectional charging and discharging of the energy storage inverter.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a voltage control method for an island distribution station area including a fixed-frequency energy storage converter, comprising the following steps:

[0009] S1 collects and processes signals, wherein the processed signals include satellite timing pulse signals, three-phase voltage signals of the grid connection point, and output current signals of the energy storage converter;

[0010] S2 calculates the effective value of the phase voltage according to the satellite timing pulse signal and the three-phase voltage signal of the grid connection point, and obtains the effective value instruction of the output current of the energy storage converter according to the relationship curve between the current signal output by the energy storage converter and the effective value of the phase voltage;

[0011] During operation, S3 obtains the control mode of the energy storage converter according to the calculated range of the effective value of the phase voltage, and obtains the output current effective value instruction of the energy storage converter when the load fluctuates by changing the relationship curve between the output current signal of the energy storage converter and the effective value of the phase voltage;

[0012] S4 performs closed-loop control on the output current or port voltage of the energy storage converter according to the three-phase voltage signal of the grid connection point, the output current signal of the energy storage converter, the control mode of the energy storage converter and the output current effective value instruction.

[0013] As an optional implementation, the output current effective value instruction of the energy storage converter is obtained, specifically:

[0014] The controller in the energy storage converter is used to capture the rising edge of the satellite timing pulse signal, and the real-time phase ωt of the set frequency is obtained by using the crystal oscillator of the internal oscillator of the controller. The phase signal is reset to zero at the rising edge of the next pulse signal, and the sine function value and cosine function value are calculated.

[0015] The three-phase voltage signals are transformed by positive sequence Clarke transform and Park transform with angular velocity ω to obtain their values ​​u in the rotating coordinate system. d and u q , obtain the effective value of phase voltage;

[0016] According to the relationship curve between the current signal output by the energy storage converter and the effective value of the phase voltage, the effective value command of the output current of the energy storage converter is:

[0017]

[0018] Where, U is the effective value of phase voltage, U N ,I N They are respectively the rated voltage and rated current of the energy storage converter in the distribution station area.

[0019] As an optional implementation, the operation matrix of the positive-sequence Clarke transform is:

[0020]

[0021] The operation matrix of the Park transform rotating at an angular velocity ω is:

[0022]

[0023] Among them, sinωt is the sine function value of the real-time phase, and cosωt is the cosine function value of the real-time phase.

[0024] As an optional implementation, the control mode of the energy storage converter is obtained according to the calculated range of the effective value of the phase voltage, specifically:

[0025] When the effective value of the phase voltage is greater than the first threshold or less than the second threshold, the current control mode is adopted;

[0026] When the absolute value of the output current effective value instruction is less than the third threshold, the control mode of the energy storage converter is switched from the current control mode to the constant voltage control mode.

[0027] As an optional implementation, by changing the relationship curve between the output current command of the energy storage converter and the effective value of the phase voltage, the output current effective value command of the energy storage converter when the load fluctuates is obtained, specifically:

[0028] According to the effective value of the phase voltage, record the current instructions corresponding to the effective values ​​of the different phase voltages in the recent times, and determine the changing law of the effective value of the phase voltage;

[0029] According to the current operating state of the energy storage converter and the change law of the effective value of the phase voltage, the relationship curve between the output current command of the energy storage converter and the effective value of the phase voltage is changed to obtain the effective value command of the output current of the energy storage converter when the load fluctuates.

[0030] As an optional implementation, the output current or port voltage of the energy storage converter is closed-loop controlled, specifically:

[0031] According to the different operating states of the current energy storage converter, different methods are used for calculation to obtain the three-phase voltage modulation wave signal, which is compared with the carrier signal set in the controller to obtain the pulse signal for driving the switch tube, and then the switch device is controlled to be turned on and off after passing through the drive circuit.

[0032] In a second aspect, the present invention provides an island distribution station area voltage control system including a fixed-frequency energy storage converter, comprising:

[0033] The data acquisition module is configured to: collect and process signals, wherein the processed signals include satellite timing pulse signals, three-phase voltage signals of the grid connection point, and output current signals of the energy storage converter;

[0034] The calculation module is configured to: calculate the effective value of the phase voltage according to the satellite timing pulse signal and the three-phase voltage signal of the grid connection point, and obtain the effective value instruction of the output current of the energy storage converter according to the relationship curve between the current signal output by the energy storage converter and the effective value of the phase voltage;

[0035] The control mode determination module is configured to: during operation, obtain the control mode of the energy storage converter according to the calculated range of the effective value of the phase voltage, and obtain the output current effective value instruction of the energy storage converter when the load fluctuates by changing the relationship curve between the output current signal of the energy storage converter and the effective value of the phase voltage;

[0036] The output module is configured to perform closed-loop control on the output current or port voltage of the energy storage converter according to the three-phase voltage signal of the grid connection point, the output current signal of the energy storage converter, the control mode of the energy storage converter and the output current effective value instruction.

[0037] In a third aspect, the present invention provides an electronic device comprising a memory and a processor, and computer instructions stored in the memory and executed on the processor, wherein when the computer instructions are executed by the processor, the method described in the first aspect is performed.

[0038] In a fourth aspect, the present invention provides a computer-readable storage medium for storing computer instructions, wherein when the computer instructions are executed by a processor, the method described in the first aspect is performed.

[0039] In a fifth aspect, the present invention provides a computer program product, comprising a computer program, which, when executed by a processor, implements the method described in the first aspect.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The present disclosure proposes a voltage control method and system for an isolated distribution station area containing a fixed-frequency energy storage inverter. Under the premise of improving the power-angle stability and frequency stability problems of the high-proportion distribution station area during autonomous operation, on the one hand, the technical solution of the present disclosure does not need to change the control strategy of the installed photovoltaic and wind turbine inverters, and can be well applied to the distribution network containing a high proportion of new energy; on the other hand, the technical solution of the present disclosure takes into account the quality of AC bus voltage under large-scale fluctuations of new energy and load, and considers the voltage performance of the energy storage inverter during bidirectional charging and discharging, especially when the power of new energy power sources such as photovoltaics and wind turbines and the load power are equal, the system can still ensure constant frequency operation.

[0042] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will become obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0044] Figure 1 A flow chart of a voltage control method for an island distribution station area containing a fixed-frequency energy storage converter provided in Example 1 of the present invention;

[0045] Figure 2 A schematic diagram of a module of an island distribution station area voltage control system including a fixed-frequency energy storage converter provided in Example 2 of the present invention;

[0046] Figure 3 It is a schematic diagram of the relationship between the current output instruction and the voltage effective value of the present invention. DETAILED DESCRIPTION

[0047] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0048] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0049] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that the terms "include" and "have" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0051] Example 1

[0052] like Figure 1 As shown, this embodiment provides a voltage control method for an island distribution station area including a fixed-frequency energy storage converter, comprising the following steps:

[0053] S1 collects and processes signals, wherein the processed signals include satellite timing pulse signals, three-phase voltage signals of the grid connection point, and output current signals of the energy storage converter.

[0054] S2 calculates the effective value of the phase voltage based on the satellite timing pulse signal and the three-phase voltage signal of the grid connection point, and obtains the effective value instruction of the output current of the energy storage inverter based on the relationship curve between the current signal output by the energy storage inverter and the effective value of the phase voltage.

[0055] During operation, S3 obtains the control mode of the energy storage converter according to the calculated range of the effective value of the phase voltage, and obtains the output current effective value instruction of the energy storage converter when the load fluctuates by changing the relationship curve between the output current signal of the energy storage converter and the effective value of the phase voltage.

[0056] S4 performs closed-loop control on the output current or port voltage of the energy storage converter according to the three-phase voltage signal of the grid connection point, the output current signal of the energy storage converter, the control mode of the energy storage converter and the output current effective value instruction.

[0057] In S2, the process of obtaining the output current effective value instruction of the energy storage converter is:

[0058] S21 uses the controller in the energy storage converter to capture the rising edge of the second pulse signal, uses the crystal oscillator of the controller's internal oscillator to obtain the 50Hz real-time phase ωt, and resets the phase signal to zero at the rising edge of the next second pulse signal, where t is the time, and calculates the sine function value sinωt and the cosine function value cosωt;

[0059] S22 transforms the three-phase voltage acquisition signal through positive sequence Clarke transformation and Park transformation rotating at angular velocity ω to obtain its value u in the rotating coordinate system. d and u q , the phase voltage effective value U can be further expressed as:

[0060]

[0061] According to the effective value of the phase voltage U, the output current effective value instruction of the energy storage converter is:

[0062]

[0063] Where U N ,I N are the rated voltage and rated current of the energy storage converter in the distribution area. For the low-voltage distribution area, U N is 220V, when I N When it is a positive value, it means that the energy storage converter emits active power, otherwise it means that the energy storage converter absorbs active power.

[0064] S24 defines the variable of the operating status of the energy storage converter in the controller and sets its status to 1.

[0065] For the positive sequence Clarke transform, its operation matrix T p It is expressed as:

[0066]

[0067] For the Park transform rotating at an angular velocity ω, the operation matrix T ω It is expressed as:

[0068]

[0069] In S3, the process of obtaining the output current effective value instruction of the energy storage converter when the load fluctuates is as follows:

[0070] S31 records the current instructions corresponding to the three most recent different phase voltage effective values ​​according to the phase voltage effective value, and determines the changing rule of the phase voltage effective value.

[0071] S32 If the current energy storage converter operation state is 1, the phase voltage effective value shows an upward trend and the phase voltage effective value is greater than 1.055U N Time (corresponding to Figure 3 A1 in the figure), the output current effective value instruction of the energy storage converter is:

[0072]

[0073] And set the operating state of the energy storage converter to 2 in the controller.

[0074] S33 If the current operating state of the energy storage converter is 2.

[0075] S331 meets the requirement that the phase voltage effective value shows an upward trend and the phase voltage effective value is greater than 1.055U N Time (corresponding to Figure 3 B1 in the figure), the energy storage converter switches to the constant voltage and constant frequency control mode, where the frequency is 50Hz, the phase voltage effective value instruction is 220V, and the value u of the three-phase acquisition voltage in the rotating coordinate system at the moment of transition is calculated and recorded d0 and u q0 .

[0076] Set the energy storage converter operating state to 3 in the controller.

[0077] S332 meets the requirement that the effective value of phase voltage shows a downward trend and the effective value of phase voltage is less than 0.945U N Time (corresponding to Figure 3 A2 in the figure), the energy storage converter output current effective value instruction is:

[0078]

[0079] And set the energy storage converter operating state to 1 in the controller.

[0080] S34 If the current energy storage converter operation state is 3, the detected three-phase current of the energy storage converter is subjected to positive sequence Clarke transformation and Park transformation with angular velocity rotation to obtain its value i in the rotating coordinate system. d andi q , and then calculate the effective value of the current.

[0081] S341 When its value is greater than 0.35I N (correspond Figure 3 When the direction satisfies the energy storage converter to absorb power, the output current effective value instruction of the energy storage converter is:

[0082]

[0083] At the same time, the operating state of the energy storage converter is set to 4 in the controller.

[0084] S342 When its value is greater than 0.35I N , and the direction satisfies the energy storage converter when it sends power (corresponding to Figure 3 B2 in the figure), the output current effective value instruction of the energy storage converter is:

[0085]

[0086] At the same time, the operating state of the energy storage converter is set to 2 in the controller.

[0087] S35 If the current operating state of the energy storage converter is 4.

[0088] S351 meets the requirement that the phase voltage effective value shows an upward trend and the phase voltage effective value is greater than 1.055U N Time (corresponding to Figure 3 D2 in the figure), the output current effective value instruction of the energy storage converter is:

[0089]

[0090] At the same time, the operating state of the energy storage converter is set to 5 in the controller.

[0091] S352 meets the condition that the phase voltage effective value shows a downward trend and the phase voltage effective value is less than 0.945U N Time (corresponding to Figure 3 C1 in the figure), the energy storage converter switches to the constant voltage and constant frequency control mode, where the frequency is 50Hz, the phase voltage effective value instruction is 220V, and the value u of the three-phase acquisition voltage in the rotating coordinate system at the moment of transition is calculated and recorded d0and u q0 .

[0092] At the same time, the operating state of the energy storage converter is set to 3 in the controller.

[0093] S36 If the current energy storage converter operation state is 5, the phase voltage effective value shows an upward trend and the phase voltage effective value is less than 0.945U N Time (corresponding to Figure 3 D1 in the figure), the output current effective value instruction of the energy storage converter is:

[0094]

[0095] At the same time, the operating state of the energy storage converter is set to 4 in the controller.

[0096] In S4, the output current or the terminal voltage of the energy storage converter is closed-loop controlled, specifically:

[0097] S41 When the energy storage converter operating state is 1 or 2 or 4 or 5.

[0098] S411 uses the energy storage converter output current effective value command I and the sine function value sinωt and cosine function value cosωt calculated in step S21 to calculate the three-phase output current real-time command signal of the energy storage converter in the stationary coordinate system according to the following formula:

[0099]

[0100] S412 uses the three-phase current real-time command signal to subtract the output current signal of the detected energy storage converter, and then uses one of hysteresis control, proportional resonance control or quasi-proportional resonance control (all closed-loop control algorithms) to calculate the three-phase voltage modulation wave signal.

[0101] S42 When the energy storage converter operating state is 3.

[0102] S421 uses the value u of the three-phase voltage collected at the moment of transition recorded in step S331 or S352 in the rotating coordinate system d0 and u q0 , and the sine function value sinωt and cosine function value cosωt calculated in step S21, the three-phase output voltage command signal of the energy storage converter in the stationary coordinate system is calculated according to the following formula:

[0103]

[0104] S422 subtracts the detected three-phase voltage signal of the energy storage converter grid connection point from the three-phase output voltage command signal, and obtains a three-phase voltage modulation wave signal by using proportional resonance control or quasi-proportional resonance control (both are closed-loop control algorithms).

[0105] S43 compares the three-phase modulation wave signal calculated by S421 or S422 with the carrier signal set in the controller to obtain a pulse signal for driving the switch tube, and controls the on and off of the switch device after passing through the drive circuit.

[0106] Example 2

[0107] like Figure 2 As shown, this embodiment provides an island distribution station area voltage control system including a fixed-frequency energy storage converter, including:

[0108] The data acquisition module is configured to: collect and process signals, wherein the processed signals include satellite timing pulse signals, three-phase voltage signals of the grid connection point, and output current signals of the energy storage converter;

[0109] The calculation module is configured to: calculate the effective value of the phase voltage according to the satellite timing pulse signal and the three-phase voltage signal of the grid connection point, and obtain the effective value instruction of the output current of the energy storage converter according to the relationship curve between the current signal output by the energy storage converter and the effective value of the phase voltage;

[0110] The control mode determination module is configured to: during operation, obtain the control mode of the energy storage converter according to the calculated range of the effective value of the phase voltage, and obtain the output current effective value instruction of the energy storage converter when the load fluctuates by changing the relationship curve between the output current signal of the energy storage converter and the effective value of the phase voltage;

[0111] The output module is configured to perform closed-loop control on the output current or port voltage of the energy storage converter according to the three-phase voltage signal of the grid connection point, the output current signal of the energy storage converter, the control mode of the energy storage converter and the output current effective value instruction.

[0112] Among them, the calculation module, the control mode determination module and the output module all belong to the control module.

[0113] It should be noted that the above modules correspond to the steps described in Example 1, and the examples and application scenarios implemented by the above modules and the corresponding steps are the same, but are not limited to the contents disclosed in the above Example 1. It should be noted that the above modules, as part of the system, can be executed in a computer system such as a set of computer executable instructions.

[0114] In further embodiments, there is also provided:

[0115] An electronic device includes a memory and a processor, and computer instructions stored in the memory and executed on the processor, wherein when the computer instructions are executed by the processor, the method described in Embodiment 1 is performed. For the sake of brevity, it will not be described in detail here.

[0116] It should be understood that in this embodiment, the processor may be a central processing unit CPU, and the processor may also be other general-purpose processors, digital signal processors DSP, application-specific integrated circuits ASIC, off-the-shelf programmable gate arrays FPGA or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0117] The memory may include a read-only memory and a random access memory, and provide instructions and data to the processor. A portion of the memory may also include a non-volatile random access memory. For example, the memory may also store information about the device type.

[0118] A computer-readable storage medium is used to store computer instructions, and when the computer instructions are executed by a processor, the method described in Example 1 is completed.

[0119] The method in Example 1 can be directly embodied as a hardware processor, or a combination of hardware and software modules in the processor. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory, or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware. To avoid repetition, it is not described in detail here.

[0120] A computer program product includes a computer program, and when the computer program is executed by a processor, the method described in embodiment 1 is implemented.

[0121] The present invention also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer executable instructions, such as instructions included in a program module, which are executed in a device on a real or virtual processor of the target to perform the process / method as described above. Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functions of program modules can be combined or divided between program modules as needed. Machine executable instructions for program modules can be executed in local or distributed devices. In distributed devices, program modules can be located in local and remote storage media.

[0122] The computer program code for implementing the method of the present invention can be written in one or more programming languages. These computer program codes can be provided to the processor of a general-purpose computer, a special-purpose computer or other programmable data processing device, so that the program code, when executed by the computer or other programmable data processing device, causes the function / operation specified in the flow chart and / or block diagram to be implemented. The program code can be executed completely on a computer, partially on a computer, as an independent software package, partially on a computer and partially on a remote computer or completely on a remote computer or server.

[0123] In the context of the present invention, computer program codes or related data may be carried by any appropriate carrier to enable a device, apparatus or processor to perform the various processes and operations described above. Examples of carriers include signals, computer readable media, and the like. Examples of signals may include electrical, optical, radio, acoustic or other forms of propagation signals, such as carrier waves, infrared signals, and the like.

[0124] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with this embodiment can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0125] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A voltage control method for an island distribution station area containing a fixed-frequency energy storage converter, characterized in that: The following steps are involved: S1 collects and processes signals, wherein the processed signals include satellite timing pulse signals, three-phase voltage signals of the grid connection point, and output current signals of the energy storage converter; S2 calculates the effective value of the phase voltage according to the satellite timing pulse signal and the three-phase voltage signal of the grid connection point, and obtains the effective value instruction of the output current of the energy storage converter according to the relationship curve between the current signal output by the energy storage converter and the effective value of the phase voltage; During operation, S3 obtains the control mode of the energy storage converter according to the calculated range of the effective value of the phase voltage, and obtains the output current effective value instruction of the energy storage converter when the load fluctuates by changing the relationship curve between the output current signal of the energy storage converter and the effective value of the phase voltage; S4 performs closed-loop control on the output current or port voltage of the energy storage converter according to the three-phase voltage signal of the grid connection point, the output current signal of the energy storage converter, the control mode of the energy storage converter and the output current effective value instruction; Obtain the output current effective value instruction of the energy storage converter, specifically: The controller in the energy storage converter is used to capture the rising edge of the satellite timing pulse signal, and the real-time phase ωt of the set frequency is obtained by using the crystal oscillator of the internal oscillator of the controller. The phase signal is reset to zero at the rising edge of the next pulse signal, and the sine function value and cosine function value are calculated. The three-phase voltage signals are transformed by positive sequence Clarke transform and Park transform with angular velocity ω to obtain their values ​​in the rotating coordinate system. u d and u q , obtain the effective value of phase voltage; According to the relationship curve between the current signal output by the energy storage converter and the effective value of the phase voltage, the effective value command of the output current of the energy storage converter is: In the formula, U is the effective value of the phase voltage, U N , I N They are the rated voltage and rated current of the energy storage converter in the distribution station area respectively; By changing the relationship curve between the output current command of the energy storage converter and the effective value of the phase voltage, the output current effective value command of the energy storage converter when the load fluctuates is obtained, specifically: According to the effective value of the phase voltage, record the current instructions corresponding to the effective values ​​of the different phase voltages in the recent times, and determine the changing law of the effective value of the phase voltage; According to the current operating state of the energy storage converter and the change law of the effective value of the phase voltage, the relationship curve between the output current command of the energy storage converter and the effective value of the phase voltage is changed to obtain the effective value command of the output current of the energy storage converter when the load fluctuates; According to the effective value of the phase voltage, record the current instructions corresponding to the three most recent effective values ​​of the different phase voltages to determine the changing pattern of the effective value of the phase voltage; If the current energy storage converter operation state is 1, the phase voltage effective value shows an upward trend and the phase voltage effective value is greater than 1.055 U N When , the output current effective value instruction of the energy storage converter is: And set the energy storage converter operation state to 2 in the controller; If the current energy storage converter operation state is 2; When the effective value of the phase voltage shows an upward trend and the effective value of the phase voltage is greater than 1.055 U N When the energy storage converter switches to the constant voltage and constant frequency control mode, the frequency is 50Hz, the phase voltage effective value instruction is 220V, and the value of the three-phase acquisition voltage in the rotating coordinate system at the moment of transition is calculated and recorded. u d0 and u q0 ; Set the energy storage converter operation state to 3 in the controller; When the phase voltage effective value shows a downward trend and the phase voltage effective value is less than 0.945 U N When , the energy storage converter output current effective value instruction is: And set the energy storage converter operation state to 1 in the controller; If the current energy storage converter operation state is 3, the detected three-phase current of the energy storage converter is subjected to positive sequence Clarke transformation and Park transformation with angular velocity rotation to obtain its value in the rotating coordinate system i d and i q , and then calculate the effective value of the current; When its value is greater than 0.35 I N , and the direction satisfies the energy storage converter to absorb power, the output current effective value instruction of the energy storage converter is: At the same time, the operating state of the energy storage converter is set to 4 in the controller; When its value is greater than 0.35 I N , and the direction satisfies the energy storage converter to output power, the output current effective value instruction of the energy storage converter is: At the same time, the operating state of the energy storage converter is set to 2 in the controller; If the current energy storage converter operation state is 4; When the effective value of the phase voltage shows an upward trend and the effective value of the phase voltage is greater than 1.055 U N When , the output current effective value instruction of the energy storage converter is: At the same time, the operating state of the energy storage converter is set to 5 in the controller; When the phase voltage effective value shows a downward trend and the phase voltage effective value is less than 0.945 U N When the energy storage converter switches to the constant voltage and constant frequency control mode, the frequency is 50Hz, the phase voltage effective value instruction is 220V, and the value of the three-phase acquisition voltage in the rotating coordinate system at the moment of transition is calculated and recorded. u d0 and u q0 ; At the same time, the operating state of the energy storage converter is set to 3 in the controller; If the current energy storage converter operation state is 5, when the phase voltage effective value shows an upward trend and the phase voltage effective value is less than 0.945 U N When , the output current effective value instruction of the energy storage converter is: At the same time, the operating state of the energy storage converter is set to 4 in the controller.

2. The voltage control method for an isolated island distribution station area containing a fixed-frequency energy storage converter according to claim 1, characterized in that: The operation matrix of the positive sequence Clarke transform is: The operation matrix of the Park transform rotating at an angular velocity ω is: Among them, sinωt is the sine function value of the real-time phase, and cosωt is the cosine function value of the real-time phase.

3. The voltage control method for an isolated island distribution station area containing a fixed-frequency energy storage converter according to claim 1, characterized in that: The output current or terminal voltage of the energy storage converter is controlled in a closed loop, specifically: According to the different operating states of the current energy storage converter, hysteresis control, proportional resonance control or quasi-proportional resonance control methods are used for calculation to obtain a three-phase voltage modulation wave signal, which is compared with the carrier signal set in the controller to obtain a pulse signal for driving the switch tube, and the on and off of the switch device is controlled after passing through the drive circuit.

4. An island distribution station area voltage control system containing a fixed-frequency energy storage converter, based on an island distribution station area voltage control method containing a fixed-frequency energy storage converter as claimed in any one of claims 1 to 3, characterized in that: include: The data acquisition module is configured to: collect and process signals, wherein the processed signals include satellite timing pulse signals, three-phase voltage signals of the grid connection point, and output current signals of the energy storage converter; The calculation module is configured to: calculate the effective value of the phase voltage according to the satellite timing pulse signal and the three-phase voltage signal of the grid connection point, and obtain the effective value instruction of the output current of the energy storage converter according to the relationship curve between the current signal output by the energy storage converter and the effective value of the phase voltage; The control mode determination module is configured to: during operation, obtain the control mode of the energy storage converter according to the calculated range of the effective value of the phase voltage, and obtain the output current effective value instruction of the energy storage converter when the load fluctuates by changing the relationship curve between the output current signal of the energy storage converter and the effective value of the phase voltage; The output module is configured to perform closed-loop control on the output current or port voltage of the energy storage converter according to the three-phase voltage signal of the grid connection point, the output current signal of the energy storage converter, the control mode of the energy storage converter and the output current effective value instruction.

5. An electronic device, characterized in that: The method comprises a memory and a processor and computer instructions stored in the memory and executed on the processor, wherein when the computer instructions are executed by the processor, the method according to any one of claims 1 to 3 is completed.

6. A computer-readable storage medium, characterized in that: Used to store computer instructions, which, when executed by a processor, complete the method described in any one of claims 1 to 3.

7. A computer program product, characterized in that The invention comprises a computer program, which, when executed by a processor, implements the method according to any one of claims 1 to 3.

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