A method for judging reactive power mutual pulling of a series connection new energy station and a related device

Abstract

A reactive power mutual pulling judgment method and related device for series connection of new energy stations, comprising: comparing the reactive power of a new energy N station with a corresponding fixed value in real time; monitoring the characteristic of the actual reactive power of the controllable reactive power compensation equipment of a new energy M station, which is capacitive or inductive; judging whether mutual pulling phenomenon occurs between the M station and the N station according to the comparison result of the reactive power of the new energy N station and the corresponding fixed value and the characteristic of the actual reactive power of the controllable reactive power compensation equipment of the M station; and adjusting the reactive power of the M station according to whether the mutual pulling phenomenon occurs. If it is judged that no reactive power mutual pulling phenomenon occurs, the M station normally adjusts the reactive power of the station; if it is judged that the reactive power mutual pulling phenomenon occurs, the M station reactive power adjustment triggers the increase or decrease of the lock according to the actual situation until the reactive power mutual pulling phenomenon ends. The device is used to execute the above method. The present application effectively solves the widespread problem of reactive power mutual pulling between new energy stations, and guarantees power quality and equipment safety.

Description

Technical Field

[0001] This invention relates to the field of reactive power control technology for new energy power generation, specifically to a method and related device for judging reactive power mutual pull in series-connected new energy power plants. Background Technology

[0002] In recent years, clean energy has developed rapidly, with a large number of new energy power plants, such as wind power and photovoltaic power, being connected to the power grid. Voltage is one of the important indicators of power quality. Currently, new energy power plants are equipped with automatic voltage control (AVC) systems, as well as controllable compensation equipment such as SVG, SVC, and inverters, to ensure that the output voltage of the wind farm meets the standard requirements. Due to the limitation of the number of substation bays in the power system, most new energy power plants are connected to the grid in series.

[0003] Voltage commands issued by the AVC control system of the power grid dispatching master station can lead to reactive power regulation in opposite directions between series-connected renewable energy power plants due to various reasons. This mutual interference between power plants in the regulation process and results is known as reactive power cross-connection. Common causes of reactive power cross-connection include: data transmitted from substations to the master station comes from different acquisition devices, including primary and secondary devices; due to differences in communication speeds among these devices, the voltage commands issued from the master station to the substation AVC system are not at the same time, resulting in the substations not starting regulation simultaneously; inconsistencies in the regulation cycle and rate of each substation; and variations in line voltage drop under different operating modes and loads, leading to deviations in the voltage commands calculated by the master station AVC system.

[0004] When reactive power is mutually pulled between series-connected renewable energy power plants, it may lead to fluctuations in the output voltage of the power plants, poor power quality, low AVC voltage qualification rate, and damage to the reactive power compensation equipment in the power plants due to prolonged high-load operation. Summary of the Invention

[0005] The purpose of this invention is to provide a method and related device for judging reactive power mutual pull in series-connected new energy power plants, so as to solve the problems of power plant output voltage fluctuation, poor power quality, low AVC voltage qualification rate, and equipment damage caused by long-term high-load operation of reactive power compensation equipment in the power plant after reactive power mutual pull.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] In a first aspect, the present invention provides a method for determining reactive power interconnection in series-connected renewable energy power plants, comprising:

[0008] By comparing the reactive power of the new energy N-station with the corresponding set value in real time;

[0009] The characteristics of the actual reactive power generated by the controllable reactive power compensation equipment of the new energy M station are capacitive or inductive.

[0010] Based on the comparison results of the reactive power of the new energy N station with the corresponding set value and the characteristics of the actual reactive power generated by the controllable reactive power compensation equipment of the M station, it is determined whether there is a mutual pull phenomenon between the M station and the N station.

[0011] Adjust the reactive power of station M based on whether mutual pull occurs.

[0012] Optional, the corresponding fixed values ​​are as follows:

[0013] Three fixed values, A, B, and C, are set for comparison and judgment. Fixed value A is the upper limit of reactive power of the new energy N station, fixed value B is the lower limit of reactive power of the new energy N station, and fixed value C is the dead zone of reactive power variation of the new energy N station.

[0014] Optional, three cases for the comparison results:

[0015] The reactive power of station N is greater than or equal to a set value A, the reactive power of station N is less than or equal to a set value B, and the change in reactive power of station N within a set time does not exceed a set value C.

[0016] Optionally, when the reactive power of station N is greater than or equal to a set value A, if the actual reactive power generated by the controllable reactive power compensation equipment of station M is capacitive, it is determined that there is no reactive power mutual pull between station M and station N, and the AVC control system of station M normally adjusts the reactive power of this station; if the actual reactive power generated by the controllable reactive power compensation equipment of station M decreases from capacitive to inductive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation reduction interlock of station M, and sending the signal to the power grid dispatch master station; if the actual reactive power generated by the controllable reactive power compensation equipment of station M is inductive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation reduction interlock of station M, and sending the signal to the power grid dispatch master station.

[0017] Optionally, when the reactive power of station N is less than or equal to a set value B, if the actual reactive power generated by the controllable reactive power compensation equipment of station M is inductive, it is determined that there is no reactive power mutual pull between station M and station N, and the AVC control system of station M normally adjusts the reactive power of this station; if the actual reactive power generated by the controllable equipment of station M increases from inductive to capacitive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation increase interlock of station M, and sending the signal to the power grid dispatch master station; if the actual reactive power generated by the controllable reactive power compensation equipment of station M is capacitive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation increase interlock of station M, and sending the signal to the power grid dispatch master station.

[0018] Optionally, if the change in reactive power of station N does not exceed the set value C within a set time, it is determined that there is no reactive power mutual pull between station M and station N, and the AVC control system of station M normally adjusts the reactive power of this station.

[0019] Secondly, the present invention provides a reactive power mutual pull judgment system for series-connected new energy power plants, comprising:

[0020] The reactive power comparison module is used to compare the reactive power of the new energy N-station with the corresponding set value in real time.

[0021] The controllable reactive power equipment monitoring module is used to monitor whether the actual reactive power generated by the controllable reactive power compensation equipment of the new energy M station is capacitive or inductive.

[0022] The reactive power mutual pull judgment module is used to determine whether there is a mutual pull phenomenon between the M station and the N station based on the comparison result of the reactive power of the N station and the corresponding set value and the characteristics of the actual reactive power generated by the controllable reactive power compensation equipment of the M station.

[0023] The execution module is used to adjust the reactive power of station M based on whether a mutual pull phenomenon occurs.

[0024] Thirdly, the present invention provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of a method for determining reactive power mutual pull in series-connected new energy power plants.

[0025] Fourthly, the present invention provides a computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, it implements the steps of a method for determining reactive power mutual pull in a series-connected renewable energy power station.

[0026] Compared with the prior art, the present invention has the following technical effects:

[0027] The method of this invention is simple and easy to implement. By comparing the reactive power of the new energy station N with the setpoints A, B, and C, and simultaneously monitoring the actual reactive power generated by the controllable reactive power compensation equipment of the new energy station M, it can determine whether there is a reactive power mutual pull between the new energy stations M and N, and take corresponding measures to effectively solve the currently widespread problem of reactive power mutual pull between new energy power plants. This invention has low modification costs and is well-suited for large-scale application. Attached Figure Description

[0028] Figure 1 This is a flowchart of the control method of the present invention.

[0029] Figure 2 This is a diagram of the primary system of a series-connected new energy power station according to an embodiment of the present invention.

[0030] Figure 3 This is a schematic diagram of a module for resolving reactive power interconnection in a series-connected renewable energy power plant according to an embodiment of the present invention.

[0031] Figure 4This is a schematic diagram of the structure of the electronic device provided in an embodiment of the present invention. Detailed Implementation

[0032] An embodiment of the present invention will now be further described with reference to the accompanying drawings:

[0033] This invention provides a method for determining reactive power interconnection in series-connected renewable energy power plants, including:

[0034] By comparing the reactive power of the new energy N-station with the corresponding set value in real time;

[0035] The characteristics of the actual reactive power generated by the controllable reactive power compensation equipment of the new energy M station are capacitive or inductive.

[0036] Based on the comparison results of the reactive power of the new energy N station with the corresponding set value and the characteristics of the actual reactive power generated by the controllable reactive power compensation equipment of the M station, it is determined whether there is a mutual pull phenomenon between the M station and the N station.

[0037] Adjust the reactive power of station M based on whether mutual pull occurs.

[0038] The present invention provides a method for judging reactive power mutual pull between series-connected renewable energy power plants. By comparing the reactive power of renewable energy power plant N with the corresponding set value in real time, and simultaneously monitoring the actual reactive power generated by the controllable reactive power compensation equipment of renewable energy power plant M, the method can determine whether reactive power mutual pull occurs between renewable energy power plants M and N, and take corresponding measures.

[0039] Three fixed values, A, B, and C, are set for comparison and judgment. Fixed value A is the upper limit of reactive power of the new energy N station, fixed value B is the lower limit of reactive power of the new energy N station, and fixed value C is the dead zone of reactive power variation of the new energy N station.

[0040] like Figure 2 As shown, the new energy power station M and power station N are connected to the power grid in series. Power station M has relevant data such as the reactive power of power station N. Therefore, by comparing the reactive power of new energy power station N with the values ​​A, B, and C, and simultaneously monitoring the actual reactive power generated by the controllable reactive power compensation equipment of new energy power station M, it is possible to determine whether there is a reactive power mutual pull between new energy power stations M and N, and take corresponding measures.

[0041] like Figure 1As shown, when the reactive power of station N is greater than or equal to the set value A, if the actual reactive power generated by the controllable reactive power compensation equipment of station M is capacitive, it is determined that there is no reactive power mutual pull between station M and station N, and the AVC control system of station M normally regulates the reactive power of the station; if the actual reactive power generated by the controllable reactive power compensation equipment of station M decreases from capacitive to inductive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation reduction interlock of station M, and sending the signal to the power grid dispatch master station; if the actual reactive power generated by the controllable reactive power compensation equipment of station M is inductive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation reduction interlock of station M, and sending the signal to the power grid dispatch master station.

[0042] When the reactive power of station N is less than or equal to the set value B, if the actual reactive power generated by the controllable reactive power compensation equipment of station M is inductive, it is determined that there is no reactive power mutual pull between station M and station N, and the AVC control system of station M adjusts the reactive power of the station normally; if the actual reactive power generated by the controllable equipment of station M increases from inductive to capacitive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation increase interlock of station M, and sending the signal to the power grid dispatch master station; if the actual reactive power generated by the controllable reactive power compensation equipment of station M is capacitive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation increase interlock of station M, and sending the signal to the power grid dispatch master station.

[0043] If the change in reactive power at station N does not exceed a set value C within a certain period of time, it is determined that there is no reactive power mutual pull between station M and station N, and the AVC control system of station M normally adjusts the reactive power of the station.

[0044] like Figure 3 As shown, an embodiment of the present invention provides a reactive power interconnection solution device for series-connected new energy power plants, comprising:

[0045] The reactive power comparison module is used to determine the actual reactive power generation of station N, whether it exceeds the upper limit A or is lower than the lower limit B of station N, and whether the reactive power change is less than the dead zone setting C.

[0046] The controllable reactive power equipment monitoring module is used to monitor the actual reactive power generated by the controllable reactive power compensation equipment of the new energy M station, determine whether the actual reactive power is capacitive or inductive, and determine whether the trend of the actual reactive power change is from capacitive to inductive or from inductive to capacitive.

[0047] The reactive power mutual pull judgment module integrates information from the reactive power comparison module and the controllable reactive power equipment monitoring module, and determines whether a reactive power mutual pull phenomenon occurs between the new energy M station and N station according to the aforementioned reactive power mutual pull judgment method.

[0048] The execution module, based on the information from the reactive power interconnection judgment module, adopts the method described above and issues corresponding instructions to resolve the reactive power interconnection problem of series-connected new energy power plants.

[0049] The module division in this embodiment of the invention is illustrative and represents only one logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the invention can be integrated into a single processor, exist as separate physical entities, or be integrated into a single module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0050] Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of the present invention includes: a processor, a memory, input units such as a keyboard and mouse, a signal acquisition input unit, a display, an instruction signal output unit, and a power supply.

[0051] The processor can call programs stored in memory to execute the method flow. The memory stores the method flow and other programs required for execution, as well as data such as reactive power input from the acquired signals and the actual reactive power generation of controllable reactive power equipment. A mouse and keyboard are used to perform corresponding input operations. The signal acquisition input unit inputs relevant signals from the relay protection room control cabinet of the new energy power station to the equipment, such as the actual reactive power generation of station N and the actual reactive power generation of controllable equipment at station M. A display is used to show relevant data in real time, such as reactive power curves, actual reactive power generation curves of controllable equipment, reactive power inter-pull judgment status, and instructions. The instruction output unit outputs instructions from the execution module to the relay protection room AVC system. A communication bus is used to realize data communication between units. The power supply includes mains power and a UPS to power the equipment.

[0052] In another embodiment of the present invention, a computer device is provided, comprising a processor and a memory. The memory stores a computer program, which includes program instructions. The processor executes the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing and control core of the terminal, suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions in the computer storage medium to achieve a corresponding method flow or corresponding function. The processor described in this embodiment of the present invention can be used in the operation of a method for determining reactive power mutual pull in a series-connected renewable energy power station.

[0053] In another embodiment of the present invention, a storage medium is provided, specifically a computer-readable storage medium (Memory). This computer-readable storage medium is a memory device within a computer device, used to store programs and data. It is understood that the computer-readable storage medium here can include both the built-in storage medium of the computer device and extended storage media supported by the computer device. The computer-readable storage medium provides storage space containing the terminal's operating system. Furthermore, this storage space also contains one or more instructions suitable for loading and execution by a processor. These instructions can be one or more computer programs (including program code). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk storage device. The processor can load and execute one or more instructions stored in the computer-readable storage medium to implement the corresponding steps of the reactive power mutual pull judgment method for a series-connected renewable energy power station in the above embodiments.

[0054] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0055] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0056] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0057] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for determining reactive power interconnection in a series-connected renewable energy power plant, characterized in that, include: By comparing the reactive power of the new energy N-station with the corresponding set value in real time; The characteristics of the actual reactive power generated by the controllable reactive power compensation equipment of the new energy M station are capacitive or inductive. Based on the comparison results of the reactive power of the new energy N station with the corresponding set value and the characteristics of the actual reactive power generated by the controllable reactive power compensation equipment of the M station, determine whether there is a mutual pull phenomenon between the M station and the N station. Adjust the reactive power of station M based on whether mutual pull occurs; The corresponding fixed value is specifically: Three fixed values ​​A, B, and C are set for comparison and judgment. Fixed value A is the upper limit of reactive power of the new energy N station, fixed value B is the lower limit of reactive power of the new energy N station, and fixed value C is the dead zone of reactive power change of the new energy N station. When the reactive power of station N is greater than or equal to the set value A, if the actual reactive power generated by the controllable reactive power compensation equipment of station M is capacitive, it is determined that there is no reactive power mutual pull between station M and station N, and the AVC control system of station M normally adjusts the reactive power of this station. If the actual reactive power generated by the controllable reactive power compensation equipment at station M decreases from capacitive to inductive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation reduction interlock at station M, and sending the signal to the power grid dispatch master station. If the actual reactive power generated by the controllable reactive power compensation equipment at station M is inductive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation reduction interlock at station M, and sending the signal to the power grid dispatch master station. When the reactive power of station N is less than or equal to the set value B, if the actual reactive power generated by the controllable reactive power compensation equipment of station M is inductive, it is determined that there is no reactive power mutual pull between station M and station N, and the AVC control system of station M normally adjusts the reactive power of this station. If the actual reactive power generated by the controllable equipment at station M increases from inductive to capacitive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation increase interlock at station M, and sending the signal to the power grid dispatch master station. If the actual reactive power generated by the controllable reactive power compensation equipment at station M is capacitive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation increase interlock at station M, and sending the signal to the power grid dispatch master station.

2. The method for determining reactive power interconnection in a series-connected new energy power station according to claim 1, characterized in that, If the change in reactive power at station N does not exceed the set value C within a set time, it is determined that there is no reactive power mutual pull between station M and station N, and the AVC control system of station M normally adjusts the reactive power of this station.

3. A reactive power mutual pull judgment system for series-connected new energy power plants, characterized in that, include: The reactive power comparison module is used to compare the reactive power of the new energy N-station with the corresponding set value in real time. The controllable reactive power equipment monitoring module is used to monitor whether the actual reactive power generated by the controllable reactive power compensation equipment of the new energy M station is capacitive or inductive. The reactive power mutual pull judgment module is used to determine whether there is a mutual pull phenomenon between the M station and the N station based on the comparison result of the reactive power of the N station and the corresponding set value and the characteristics of the actual reactive power generated by the controllable reactive power compensation equipment of the M station. The execution module is used to adjust the reactive power of station M based on whether a mutual pull phenomenon occurs; The corresponding fixed value is specifically: Three fixed values ​​A, B, and C are set for comparison and judgment. Fixed value A is the upper limit of reactive power of the new energy N station, fixed value B is the lower limit of reactive power of the new energy N station, and fixed value C is the dead zone of reactive power change of the new energy N station. When the reactive power of station N is greater than or equal to the set value A, if the actual reactive power generated by the controllable reactive power compensation equipment of station M is capacitive, it is determined that there is no reactive power mutual pull between station M and station N, and the AVC control system of station M normally adjusts the reactive power of this station. If the actual reactive power generated by the controllable reactive power compensation equipment at station M decreases from capacitive to inductive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation reduction interlock at station M, and sending the signal to the power grid dispatch master station. If the actual reactive power generated by the controllable reactive power compensation equipment at station M is inductive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation reduction interlock at station M, and sending the signal to the power grid dispatch master station. When the reactive power of station N is less than or equal to the set value B, if the actual reactive power generated by the controllable reactive power compensation equipment of station M is inductive, it is determined that there is no reactive power mutual pull between station M and station N, and the AVC control system of station M normally adjusts the reactive power of this station. If the actual reactive power generated by the controllable equipment at station M increases from inductive to capacitive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation increase interlock at station M, and sending the signal to the power grid dispatch master station. If the actual reactive power generated by the controllable reactive power compensation equipment at station M is capacitive, it is determined that there is a reactive power mutual pull between station M and station N, triggering the reactive power regulation increase interlock at station M, and sending the signal to the power grid dispatch master station.

4. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the reactive power mutual pull judgment method for a series-connected new energy power station as described in any one of claims 1 to 2.

5. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the reactive power mutual pull judgment method for a series-connected new energy power station as described in any one of claims 1 to 2.

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