System and method for analyzing transient stability of distributed synchronous phase modifier of wind and light field station

Abstract

The invention provides a wind and light field station distributed synchronous phase modifier transient stability analysis system and method, and the system comprises a phase modifier access unit, a power grid power collection unit, a phase modifier rotating speed collection unit, an active power acquisition unit, a voltage judgment unit, an analysis unit, and a processor unit. The input end of the power grid power acquisition unit is connected with the phase modifier access unit, the output end of the power grid power acquisition unit is connected with the processor unit, and the active power acquisition unit, the voltage judgment unit and the analysis unit are respectively connected with the processor unit. The new energy station power output limit and influence factor sensitivity analysis can be analyzed, the new energy station has the power system voltage stability supporting capability through the configuration and transient research of the new energy station distributed phase modifier, and the short circuit ratio of the new energy system station is improved through the configuration of the phase modifier. And large-scale delivery of new energy power is supported.

Description

Technical Field

[0001] The present application relates to the technical field of phase regulator stability analysis, and in particular to a system and method for transient stability analysis of distributed synchronous phase regulators in wind and solar power stations. Background Art

[0002] my country's energy and electricity show the trend of accelerating clean energy production, highly electrified energy consumption, and increasingly efficient energy utilization. Building a new power system with four important characteristics of safety and efficiency, clean and low-carbon, flexible and intelligent integration is to promote energy transformation. In recent years, the installed capacity of new energy has grown rapidly. By the end of February 2024, the country's cumulative installed capacity of power generation was about 2.97 billion kilowatts, a year-on-year increase of 14.7%. Among them, the installed capacity of solar power generation was about 650 million kilowatts, a year-on-year increase of 56.9%; the installed capacity of wind power was about 450 million kilowatts, a year-on-year increase of 21.3%. From a geographical point of view, China's large-scale wind and light resources are mostly distributed in the northwest, north China and northeast China, namely the "three norths" region. However, due to the strong volatility of wind and light resources, insufficient power grid transmission capacity and stability, it is difficult to alleviate the phenomenon of wind and light abandonment in the three norths. In 2023, the national wind abandonment rate was 2.7% and the light abandonment rate was 2.0%, of which the Ningxia Hui Autonomous Region had a wind abandonment rate of 2.2% and a light abandonment rate of 3.6%.

[0003] The power of wind power and photovoltaic power is difficult to accurately predict due to its inherent uncertainty of random fluctuations. Random fluctuations in power may cause a serious imbalance between power generation and load, thereby causing large frequency deviations or voltage stability problems, and increasing system operation risks. In power systems with low inertia and limited frequency response capabilities, the uncertainty of wind power and photovoltaic power has a particularly significant negative impact on the system. When the power of grid-connected renewable energy fluctuates, the system needs to provide more flexible power sources to balance the fluctuations in wind power output, but the increase in the penetration rate of renewable energy will correspondingly reduce the proportion of flexible power sources, resulting in insufficient grid flexibility, which creates a contradiction between the output characteristics of renewable energy and the power system's requirements for power output. As the proportion of renewable energy installed capacity increases, this contradiction becomes increasingly severe and gradually becomes a bottleneck restricting the further development of the new energy industry.

[0004] The wind-solar hybrid power generation system is one of the important implementation paths to deal with the volatility and intermittency of new energy. In recent years, the problem of transient overvoltage suppression in new energy power stations has become one of the hot issues in the power industry. Since the phase-shifting machine is a rotating device, the investment cost and maintenance cost are high, and the site selection is more difficult. Therefore, it is necessary to study the phase-shifting machine layout plan to effectively improve the transient stability of the system voltage and meet the economic requirements as much as possible. The existing technology proposes a distributed / centralized hybrid optimization configuration plan with the minimum short-circuit ratio index requirement as the goal, but it pays less attention to the transient voltage stability of the system. Summary of the invention

[0005] The present application provides a system and method for transient stability analysis of distributed synchronous phase regulators in wind and solar power stations to solve the problem of low analysis efficiency in the prior art, and realizes the configuration and transient research of distributed synchronous phase regulators in new energy stations, so that new energy stations have the ability to support voltage stability of the power system.

[0006] The present application provides a transient stability analysis system for a distributed synchronous phase condenser in a wind-solar station, comprising a phase condenser access unit, a power grid power collection unit, a phase condenser speed collection unit, an active power acquisition unit, a voltage judgment unit, an analysis unit and a processor unit;

[0007] The phase regulator access unit is connected to the power grid. The phase regulator is a synchronous motor that improves the short-circuit capacity of the power grid system, enhances the voltage support strength of the power grid system, and improves the voltage support capability when a fault occurs in the system.

[0008] The input end of the power grid power collection unit is connected to the phase-shifting access unit, and the output end of the power grid power collection unit is connected to the processor unit. The power grid power collection unit is used to collect the operating power of the power grid and output it to the processor unit;

[0009] The active power acquisition unit, voltage judgment unit, and analysis unit are respectively connected to the processor unit. The active power acquisition unit is used to acquire the active power of the power grid; the voltage judgment unit is used to judge whether a power grid system fails according to the output voltage; and the analysis unit is used to analyze the transient state of the phase modulator according to the judgment result.

[0010] Preferably, it also includes a wind farm short-circuit ratio monitoring unit and a photovoltaic field short-circuit ratio monitoring unit, wherein the wind farm short-circuit ratio monitoring unit and the photovoltaic field short-circuit ratio monitoring unit are respectively connected to the processor unit, and the wind farm short-circuit ratio monitoring unit is used to calculate the wind farm short-circuit ratio; the photovoltaic field short-circuit ratio monitoring unit is used to calculate the photovoltaic field short-circuit ratio.

[0011] Preferably, it also includes an early warning unit, which is connected to the processor unit and is used to send out an early warning signal when an abnormality in the power grid system is detected.

[0012] Preferably, a method for using a distributed synchronous phase condenser transient stability analysis system for a wind-solar station comprises the following steps:

[0013] A. First, connect the phase-converter access unit to the grid;

[0014] B. The power grid power acquisition unit, the phase shifter speed acquisition unit, and the active power acquisition unit respectively acquire the operating power of the grid, the speed of the phase shifter, and the active power output of the grid;

[0015] C. The acquired data is transmitted to the processor unit, and the voltage judgment unit is used to judge the operation status of the power grid. If the change rate of the power grid's operation power and the speed change rate of the phase regulator are greater than the preset value, it is judged that the power grid is abnormal, otherwise, the power grid is operating normally;

[0016] D. At the same time, the wind farm short-circuit ratio monitoring unit and the photovoltaic farm short-circuit ratio monitoring unit respectively detect the short-circuit capacity of the power grid system and calculate the short-circuit ratio;

[0017] E. The early warning unit determines whether the short circuit ratio is less than a preset threshold value and issues an early warning signal;

[0018] F. The analysis unit determines whether the phase-shifting machine is transiently stable based on the monitored grid operation data, short-circuit ratio and change rate data, and promptly feeds back the analysis results.

[0019] Preferably, the wind farm short circuit ratio monitoring unit monitoring method is as follows:

[0020] a. Measure the system short-circuit capacity of the wind farm power system at the grid connection point of each wind turbine generator set in the wind farm;

[0021] b. Calculate the short-circuit ratio of each wind turbine generator set relative to the wind farm power system based on the capacity of each wind turbine generator set and the short-circuit capacity of the power grid system;

[0022] c. Finally, the short-circuit ratio of the wind farm is calculated based on the short-circuit ratios of all wind turbine generator sets in the wind farm relative to the wind farm power system.

[0023] Preferably, the monitoring method of the photoelectric field short-circuit ratio monitoring unit is as follows:

[0024] a. Measure the system short-circuit capacity at the grid connection point of each photovoltaic inverter in the photovoltaic field;

[0025] b. According to the capacity of each photovoltaic inverter and the short-circuit capacity of the system, the short-circuit ratio of each photovoltaic inverter relative to the power grid system is calculated;

[0026] c. The short-circuit ratio of the photovoltaic field is calculated based on the short-circuit ratio of all photovoltaic inverters in the photovoltaic field relative to the photovoltaic field power grid system.

[0027] Preferably, in step E, if the short-circuit ratio of the wind farm and the short-circuit ratio of the photovoltaic farm are less than a preset threshold, an alarm message indicating that the wind farm and the photovoltaic farm are in a short-circuit ratio lower limit fault is issued.

[0028] Beneficial effects: The working principle of the present invention is simple, and it can realize the transient stability analysis of phase regulators in wind and solar power stations, and can analyze the power delivery limit of new energy stations and the sensitivity analysis of influencing factors. Through the configuration and transient research of distributed phase regulators in new energy stations, the new energy stations are equipped with the ability to support the voltage stability of the power system. At the same time, the short-circuit ratio of the new energy system station is improved through the configuration of phase regulators, supporting the large-scale transmission of new energy power.

[0029] The above description is only an overview of the technical solution of the embodiment of the present application. In order to more clearly understand the technical means of the embodiment of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present application, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 This is a block diagram of the system principle of the present invention;

[0032] Figure 2 It is the work flow chart of the present invention;

[0033] Figure 3 This is a flow chart of a wind farm short-circuit ratio monitoring unit of the present invention;

[0034] Figure 4 This is a flow chart of the photoelectric field short-circuit ratio monitoring unit of the present invention;

[0035] Explanation of the reference numerals: phase regulator access unit 1, grid power collection unit 2, phase regulator speed collection unit 3, active power acquisition unit 4, voltage judgment unit 5, analysis unit 6, processor unit 7, wind farm short-circuit ratio monitoring unit 8, photovoltaic farm short-circuit ratio monitoring unit 9, early warning unit 10. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification, claims and drawings of this application are intended to cover non-exclusive inclusions.

[0038] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiments" in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0039] In addition, the terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0040] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, the "connection" or "connection" of a mechanical structure may refer to a physical connection. For example, the physical connection may be a fixed connection, such as a fixed connection through a fixing member, such as a fixed connection through a screw, bolt or other fixing member; the physical connection may also be a detachable connection, such as a mutual snap-on or snap-fit ​​connection; the physical connection may also be an integral connection, such as a connection formed by welding, bonding or integral molding. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0041] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0042] See also Figure 1-Figure 4 , the present application discloses a wind-solar station distributed synchronous phase condenser transient stability analysis system, characterized in that it includes a phase condenser access unit 1, a power grid power collection unit 2, a phase condenser speed collection unit 3, an active power acquisition unit 4, a voltage judgment unit 5, an analysis unit 6 and a processor unit 7;

[0043] The phase regulator access unit is connected to the power grid. As a synchronous motor, the phase regulator improves the short-circuit capacity of the power grid system, enhances the voltage support strength of the power grid system, and improves the voltage support capacity when a system failure occurs. Compared with traditional large-scale phase regulators, distributed phase regulators have the advantages of high integration, stable system, short construction period, low unit capacity cost, good regulation performance, etc. At the same time, they also have better transient, sub-transient and steady-state performance, which can greatly improve the new energy transmission capacity.

[0044] The input end of the power grid acquisition unit 2 is connected to the phase shifter access unit 1, and the output end of the power grid acquisition unit 2 is connected to the processor unit 7. The power grid acquisition unit 2 is used to collect the operating power of the power grid and output it to the processor unit 7;

[0045] The active power acquisition unit 4, the voltage judgment unit 5, and the analysis unit 6 are respectively connected to the processor unit 7. The active power acquisition unit is used to acquire the active power of the power grid; the voltage judgment unit is used to judge whether a fault occurs in the power grid system according to the output voltage; and the analysis unit is used to analyze the transient state of the phase shifter according to the judgment result.

[0046] The present invention also includes a wind farm short circuit ratio monitoring unit 8 and a photovoltaic field short circuit ratio monitoring unit 9, which are respectively connected to the processor unit 7. The wind farm short circuit ratio monitoring unit is used to calculate the wind farm short circuit ratio; the photovoltaic field short circuit ratio monitoring unit is used to calculate the photovoltaic field short circuit ratio.

[0047] The present invention further comprises an early warning unit 10, wherein the early warning unit 10 is connected to the processor unit 7, and the early warning unit is used to send out an early warning signal when an abnormality of the power grid system is detected.

[0048] Working principle: A method for using a distributed synchronous condenser transient stability analysis system for a wind-solar station includes the following steps:

[0049] A. First, connect the phase-converter access unit to the grid;

[0050] B. The power grid power acquisition unit, the phase shifter speed acquisition unit, and the active power acquisition unit respectively acquire the operating power of the grid, the speed of the phase shifter, and the active power output of the grid;

[0051] C. The acquired data is transmitted to the processor unit, and the voltage judgment unit is used to judge the operation status of the power grid. If the change rate of the power grid's operation power and the speed change rate of the phase regulator are greater than the preset value, it is judged that the power grid is abnormal, otherwise, the power grid is operating normally;

[0052] D. At the same time, the wind farm short-circuit ratio monitoring unit and the photovoltaic farm short-circuit ratio monitoring unit respectively detect the short-circuit capacity of the power grid system and calculate the short-circuit ratio;

[0053] E. The early warning unit determines whether the short circuit ratio is less than a preset threshold value and issues an early warning signal;

[0054] F. The analysis unit determines whether the phase-shifting machine is transiently stable based on the monitored grid operation data, short-circuit ratio and change rate data, and promptly feeds back the analysis results.

[0055] Among them, the monitoring method of the wind farm short-circuit ratio monitoring unit is as follows:

[0056] a. Measure the system short-circuit capacity of the wind farm power system at the grid connection point of each wind turbine generator set in the wind farm;

[0057] b. Calculate the short-circuit ratio of each wind turbine generator set relative to the wind farm power system based on the capacity of each wind turbine generator set and the short-circuit capacity of the power grid system;

[0058] c. Finally, the short-circuit ratio of the wind farm is calculated based on the short-circuit ratios of all wind turbine generator sets in the wind farm relative to the wind farm power system.

[0059] In order to detect the short-circuit ratio of a wind farm, the system short-circuit capacity of the wind farm power system at the grid connection point of each wind turbine generator set in the wind farm can be measured; then, the short-circuit ratio of each wind turbine generator set relative to the wind farm power system is calculated based on the capacity of each wind turbine generator set and the system short-circuit capacity; and then, the short-circuit ratio of the wind farm is calculated based on the short-circuit ratio of all wind turbine generator sets in the wind farm relative to the wind farm power system. Since the system short-circuit capacity at the grid connection point of each wind turbine generator set in the wind farm can be measured in real time, the wind farm short-circuit ratio data can be detected in real time by using the wind farm short-circuit ratio monitoring method in the embodiment of the present invention.

[0060] The monitoring method of the photoelectric field short circuit ratio monitoring unit is as follows:

[0061] a. Measure the system short-circuit capacity at the grid connection point of each photovoltaic inverter in the photovoltaic field;

[0062] b. According to the capacity of each photovoltaic inverter and the short-circuit capacity of the system, the short-circuit ratio of each photovoltaic inverter relative to the power grid system is calculated;

[0063] c. The short-circuit ratio of the photovoltaic field is calculated based on the short-circuit ratio of all photovoltaic inverters in the photovoltaic field relative to the photovoltaic field power grid system.

[0064] Wherein, in step E, if the short circuit ratio of the wind farm and the short circuit ratio of the photovoltaic farm are less than the preset threshold, an alarm message indicating that the wind farm and the photovoltaic farm are in a short circuit ratio lower limit fault is issued.

[0065] To sum up, the working principle of the present invention is simple, and it can realize the transient stability analysis of phase regulators in wind and solar power stations, and can analyze the power delivery limit of new energy stations and the sensitivity analysis of influencing factors. Through the configuration and transient research of distributed phase regulators in new energy stations, the new energy stations are equipped with the ability to support the voltage stability of the power system. At the same time, the short-circuit ratio of the new energy system station is improved through the configuration of phase regulators, so as to support the large-scale transmission of new energy power.

[0066] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A distributed synchronous condenser transient stability analysis system for wind and solar power stations, characterized in that: It comprises a phase condenser access unit (1), a power grid power collection unit (2), a phase condenser speed collection unit (3), an active power acquisition unit (4), a voltage judgment unit (5), an analysis unit (6) and a processor unit (7); The phase regulator access unit is connected to the power grid. The phase regulator is a synchronous motor that improves the short-circuit capacity of the power grid system, enhances the voltage support strength of the power grid system, and improves the voltage support capability when a fault occurs in the system. The input end of the power grid power collection unit (2) is connected to the phase shifter access unit (1), and the output end of the power grid power collection unit (2) is connected to the processor unit (7). The power grid power collection unit (2) is used to collect the operating power of the power grid and output it to the processor unit (7); The active power acquisition unit (4), the voltage judgment unit (5) and the analysis unit (6) are respectively connected to the processor unit (7); the active power acquisition unit is used to acquire the active power of the power grid; the voltage judgment unit is used to judge whether a fault occurs in the power grid system according to the output voltage; and the analysis unit is used to analyze the transient state of the phase shifter according to the judgment result.

2. A distributed synchronous condenser transient stability analysis system for wind-solar station according to claim 1, characterized in that: It also includes a wind farm short circuit ratio monitoring unit (8) and a photovoltaic field short circuit ratio monitoring unit (9), wherein the wind farm short circuit ratio monitoring unit (8) and the photovoltaic field short circuit ratio monitoring unit (9) are respectively connected to the processor unit (7), the wind farm short circuit ratio monitoring unit is used to calculate the wind farm short circuit ratio; and the photovoltaic field short circuit ratio monitoring unit is used to calculate the photovoltaic field short circuit ratio.

3. A distributed synchronous condenser transient stability analysis system for wind-solar station according to claim 1, characterized in that: It also comprises an early warning unit (10), which is connected to the processor unit (7) and is used to send out an early warning signal when an abnormality in the power grid system is detected.

4. A method for using the distributed synchronous condenser transient stability analysis system for wind-solar station according to claim 1, characterized in that: The method of use includes the following steps: A. First, connect the phase-converter access unit to the grid; B. The power grid power acquisition unit, the phase shifter speed acquisition unit, and the active power acquisition unit respectively acquire the operating power of the grid, the speed of the phase shifter, and the active power output of the grid; C. The acquired data is transmitted to the processor unit, and the voltage judgment unit is used to judge the operation status of the power grid. If the change rate of the power grid's operation power and the speed change rate of the phase regulator are greater than the preset value, it is judged that the power grid is abnormal, otherwise, the power grid is operating normally; D. At the same time, the wind farm short-circuit ratio monitoring unit and the photovoltaic farm short-circuit ratio monitoring unit respectively detect the short-circuit capacity of the power grid system and calculate the short-circuit ratio; E. The early warning unit determines whether the short circuit ratio is less than a preset threshold value and issues an early warning signal; F. The analysis unit determines whether the phase-shifting machine is transiently stable based on the monitored grid operation data, short-circuit ratio and change rate data, and promptly feeds back the analysis results.

5. The method for using the distributed synchronous condenser transient stability analysis system for wind-solar station according to claim 4 is characterized in that: The monitoring method of the wind farm short-circuit ratio monitoring unit is as follows: a. Measure the system short-circuit capacity of the wind farm power system at the grid connection point of each wind turbine generator set in the wind farm; b. Calculate the short-circuit ratio of each wind turbine generator set relative to the wind farm power system based on the capacity of each wind turbine generator set and the short-circuit capacity of the power grid system; c. Finally, the short-circuit ratio of the wind farm is calculated based on the short-circuit ratios of all wind turbine generator sets in the wind farm relative to the wind farm power system.

6. The method for using the distributed synchronous condenser transient stability analysis system for wind-solar station according to claim 4 is characterized in that: The monitoring method of the photoelectric field short-circuit ratio monitoring unit is as follows: a. Measure the system short-circuit capacity at the grid connection point of each photovoltaic inverter in the photovoltaic field; b. According to the capacity of each photovoltaic inverter and the short-circuit capacity of the system, the short-circuit ratio of each photovoltaic inverter relative to the power grid system is calculated; c. The short-circuit ratio of the photovoltaic field is calculated based on the short-circuit ratio of all photovoltaic inverters in the photovoltaic field relative to the photovoltaic field power grid system.

7. The method for using the distributed synchronous condenser transient stability analysis system for wind-solar station according to claim 4 is characterized in that: In the step E, if the short circuit ratio of the wind farm and the short circuit ratio of the photovoltaic farm are less than the preset threshold, an alarm message indicating that the wind farm and the photovoltaic farm are in a short circuit ratio lower limit fault is issued.

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