Primary frequency modulation field test method and system of new energy system

Abstract

The invention belongs to the technical field of power system regulation and control, and particularly relates to a primary frequency modulation field test method and system of a new energy system, and the method comprises the steps: determining a primary frequency modulation field test project of the new energy system; obtaining the three-phase voltage and the output frequency of the new energy system, and carrying out the frequency self-calibration of the new energy system; acquiring the real-time voltage of the voltage frequency source and the voltage of the grid-connected point, and calculating the real-time frequency of the new energy system in combination with the self-calibrated frequency; performing real-time wave recording of the primary frequency modulation test of the new energy system according to the obtained real-time frequency to obtain wave recording data; and intercepting the obtained recording data according to the determined different test items, automatically generating a test report, and completing the primary frequency modulation field test of the new energy system.

Description

Technical Field

[0001] The present invention belongs to the technical field of power system control, and in particular relates to a primary frequency regulation field test method and system for a new energy system. 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] In order to achieve rapid power regulation of source, grid, load and storage, new energy power stations are generally equipped with rapid power control devices, which have the function of rapid active power regulation. Within the system's active power regulation capability, the system's active power can be adjusted quickly and in real time according to the regulation instructions. The system's active power can be adjusted according to the system's frequency.

[0004] like Figure 1 The fast power control device shown can be set to two active power regulation modes:

[0005] 1) Constant active power mode: Receive active power target value instructions from the dispatching master station, monitor the active power of the system grid-connected side in real time, and adjust the active output of the converter to stabilize the system active power within the target value range.

[0006] 2) Constant frequency mode: Receive the frequency target value instruction from the dispatching master station, monitor the frequency of the grid-connected side of the system in real time, and when the system frequency is abnormal, adjust the active output of the converter to stabilize the system frequency within the target value range.

[0007] At present, the on-site commissioning of primary frequency regulation in new energy power stations basically uses frequency signal generators and data recorders and analyzers. The frequency signal generator simulates the system frequency change, and the data recorder records the transmission power change of the new energy power station to test the rapid power control response function of the new energy power station. However, the existing technology has the following problems:

[0008] (1) The signal generator and the data recording and analysis device are two independent components. There is no electrical or communication connection between the two. They do not have the ability to perform automatic testing. During testing, multiple people must work together.

[0009] (2) The waveform analyzer only provides post-analysis tools and does not have intelligent decision-making capabilities. It has problems such as high technical quality requirements for testers and low testing efficiency.

[0010] (3) The data recorder is placed at the grid connection point. Since the current collection is non-contact and cannot be transmitted over long distances, it is impossible to achieve synchronous collection at multiple grid connection points when wind, solar and storage are present at the same time in new energy sources, and it is impossible to test the primary coordinated frequency modulation of new energy sources. Summary of the invention

[0011] In order to solve the above problems, the present invention proposes a field test method and system for primary frequency modulation of a new energy system, which adopts frequency self-calibration to improve the output frequency accuracy, performs on-site filtering according to the real-time changes of power and frequency and automatically generates a test report, completes the field test of the primary frequency modulation of the new energy system, and reduces the workload of the field test.

[0012] According to some embodiments, a first solution of the present invention provides a primary frequency modulation field test method for a new energy system, using the following technical solution:

[0013] A method for testing primary frequency modulation on-site of a new energy system, comprising:

[0014] Determine the primary frequency regulation on-site test items for new energy systems;

[0015] Obtain the three-phase voltage and output frequency of the new energy system and perform frequency self-calibration of the new energy system;

[0016] Obtain the real-time voltage of the voltage and frequency source and the voltage at the grid connection point, and calculate the real-time frequency of the new energy system by combining the frequency after self-calibration;

[0017] According to the obtained real-time frequency, real-time recording of a frequency modulation test of a new energy system is performed to obtain recording data;

[0018] The recorded data is intercepted according to the determined different test items, and a test report is automatically generated to complete a frequency modulation field test of the new energy system.

[0019] As a further technical limitation, the determined on-site test items for primary frequency regulation of new energy systems include at least dead zone scanning test, frequency step test, frequency disturbance test and anti-disturbance performance test.

[0020] As a further technical limitation, the voltage frequency of the new energy system is calculated based on the acquired three-phase voltage, and the obtained voltage frequency is compared with the output frequency to complete the self-calibration of the frequency of the new energy system.

[0021] As a further technical limitation, the real-time frequency of the voltage-frequency source and the grid-connected point is calculated based on the acquired voltage data of the voltage-frequency source and the voltage and current data of the grid-connected point; the obtained real-time frequency is subjected to Fourier transformation and recursive operation in sequence to obtain the real-time frequency of the new energy system.

[0022] As a further technical limitation, during a frequency modulation test, a real-time recording method is used to display the test results on a dual screen; the first screen displays multiple parameters according to time, with the start time of a frequency modulation test as the starting point, and the real-time recording records the real-time waveforms of current and voltage at each test point, and records and displays the real-time frequency curve of the voltage frequency source, the real-time amplitude curve and the real-time power of the three new energy grid-connected points in sequence according to the time axis; the second screen displays the response capability of the new energy power station to frequency changes according to the relationship between the system frequency and the real-time power of each grid-connected point.

[0023] As a further technical limitation, the real-time recording adopts frequency recording and power mutation recording; according to different test items, matching recording data are intercepted, the data is converted into waveforms and added to the test report, thereby completing the automatic generation of the test report.

[0024] According to some embodiments, a second solution of the present invention provides a primary frequency modulation field test system for a new energy system, which adopts the following technical solution:

[0025] A primary frequency modulation field test system for a new energy system, comprising:

[0026] An acquisition module configured to determine a field test item for primary frequency regulation of a new energy system;

[0027] A correction module, which is configured to obtain the three-phase voltage and output frequency of the new energy system and perform frequency self-calibration of the new energy system;

[0028] A calculation module is configured to obtain the real-time voltage of the voltage-frequency source and the grid-connected point voltage, and calculate the real-time frequency of the new energy system in combination with the self-calibrated frequency;

[0029] A wave recording module, which is configured to perform real-time wave recording of a frequency modulation test of a new energy system according to the obtained real-time frequency, and obtain wave recording data;

[0030] The test module is configured to intercept the recorded data according to the determined different test items, automatically generate a test report, and complete a frequency modulation field test of the new energy system.

[0031] According to some embodiments, a third solution of the present invention provides a computer-readable storage medium, which adopts the following technical solution:

[0032] A computer-readable storage medium stores a program, which, when executed by a processor, implements the steps of the primary frequency modulation on-site testing method of a new energy system as described in the first solution of the present invention.

[0033] According to some embodiments, a fourth solution of the present invention provides an electronic device, which adopts the following technical solution:

[0034] An electronic device comprises a memory, a processor and a program stored in the memory and running on the processor. When the processor executes the program, the steps in the primary frequency modulation on-site test method of the new energy system as described in the first scheme of the present invention are implemented.

[0035] According to some embodiments, a fifth solution of the present invention provides a computer program product, which adopts the following technical solution:

[0036] A computer program product includes software codes, wherein the program in the software codes executes the steps in the primary frequency modulation field test method of a new energy system as described in the first solution of the present invention.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The present invention adopts an integrated structural design of a voltage frequency source and a multi-grid point test data analysis system to reduce the workload of testers; improves the output frequency accuracy by frequency self-calibration to meet the test requirements of primary frequency modulation; records the wave according to real-time frequency and power changes and automatically generates a test report, which reduces the test time for testers to search for change process data in a large amount of test data and reduces the test workload. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings in the specification that constitute a part of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments of this embodiment and their descriptions are used to explain this embodiment and do not constitute improper limitations on this embodiment.

[0040] Figure 1 It is a structural diagram of rapid power control of a new energy power station in the background technology of the present invention;

[0041] Figure 2 This is an architecture diagram of a primary frequency modulation field test method for a new energy system in Embodiment 1 of the present invention;

[0042] Figure 3 This is a schematic diagram of the hardware structure of the primary frequency modulation field test method of the new energy system in the first embodiment of the present invention;

[0043] Figure 4 This is a flow chart of a primary frequency modulation on-site testing method for a new energy system in Embodiment 1 of the present invention;

[0044] Figure 5 This is a hardware architecture diagram of a primary frequency modulation test front-end unit in the first embodiment of the present invention. DETAILED DESCRIPTION

[0045] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0046] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. 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 application belongs.

[0047] 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 when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0048] In the present invention, terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are relational words determined only for the convenience of describing the structural relationships of the various parts or elements of the present invention, and do not specifically refer to any part or element in the present invention and should not be understood as limitations on the present invention.

[0049] In the present invention, terms such as "fixed connection", "connected", "connection", etc. should be understood in a broad sense, indicating that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. For relevant scientific research or technical personnel in this field, the specific meanings of the above terms in the present invention can be determined according to specific circumstances, and they cannot be understood as limitations on the present invention.

[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] Embodiment 1

[0052] Embodiment 1 of the present invention introduces a primary frequency modulation on-site testing method for a new energy system.

[0053] In this embodiment, a method for testing the primary frequency modulation on-site of a new energy system is as follows: Figure 2The architecture shown includes a host computer, a primary frequency modulation test host and a front-end acquisition unit; wherein the host computer is responsible for test data generation, data recording, real-time power analysis, waveform analysis, and automatic report generation; the primary frequency modulation test host is responsible for discretizing the function of the test data, generating a secondary voltage signal output to the fast power control unit and sampling the output voltage signal, while receiving serial optical fiber signals from three front-end units, completing the synchronous acquisition of current and voltage data of multiple grid-connected points of new energy, and processing these data to complete the primary frequency modulation test; the front-end acquisition unit realizes the digital-to-analog conversion of the current and voltage of the grid-connected point through a secondary small PT and a current clamp, and transmits it in a serial optical fiber in a Manchester encoding manner.

[0054] like Figure 3 As shown in the figure, the host computer is implemented on the PC side and is developed based on the cross-platform QT, winpcap network programming library and Lua scripting language. A friendly user interface will be designed to provide rich functional modules, such as data extraction, processing, analysis, and display. Data processing includes data decoding, synchronization and other links, which provide guarantees for subsequent data analysis and testing. The addition of Lua scripting language makes data analysis have good scalability and maintainability to adapt to future functional upgrades and changes in user needs; real-time high-precision frequency and power algorithms are key technologies of the primary frequency modulation test system. The frequency calculation adopts high-precision measurement technology based on Fourier algorithm, and the iterative convergence time is only 23ms. The power calculation adopts recursive data window to achieve power rolling output. The primary frequency modulation test host is developed using the zinq platform. The test host uses the dual-core chip zinq, FPGA is responsible for external communication and the arm core is responsible for data processing and communication with the host computer. DA conversion and power amplifier together form the current and voltage output module, and the secondary PT converter and AD conversion module together form the voltage and frequency recovery module. The Ethernet of the FPGA is connected to the control bus of the new energy power station to receive control signals from the fast control unit. The three-way FT3 data receiving module is responsible for collecting the optical fiber serial current and voltage data from the three acquisition units.

[0055] In this embodiment, if Figure 4 The primary frequency regulation field test method of the new energy system shown includes the following steps:

[0056] Step 1: Test item selection;

[0057] Step 2: Frequency signal calibration;

[0058] Step 3: Data collection;

[0059] Step 4: Real-time frequency and power calculation;

[0060] Step 5: Complete a frequency modulation test;

[0061] Step 6: Generate report automatically.

[0062] As one or more implementation modes, in step one, a frequency modulation test needs to simulate multiple system abnormal states, including dead zone scanning test, frequency step test, frequency disturbance test, anti-disturbance performance test, etc. At the same time, a state sequence method is used to realize one-button automatic testing of the above test functions. The one-button test function can also be performed in a user-defined manner.

[0063] As one or more implementation methods, in step 2, when the frequency of the new energy source is abnormal, the new energy source is quickly controlled in coordination to realize the primary frequency modulation of the new energy source. The frequency accuracy requirement is very high. In order to ensure the accuracy of the test results, the output frequency signal needs to be self-calibrated before the test; the test system collects the three-phase voltage emitted by the test system through the acquisition module composed of the secondary PT converter and the AD converter, and performs frequency calculation and compares it with the emitted frequency. The frequency accuracy of the voltage frequency source is self-calibrated.

[0064] As one or more implementation modes, in step three, in order to prevent an electrical connection between the real-time voltage of the power grid and the output voltage of the voltage-frequency source during on-site testing, thereby causing some unforeseen accidents, this embodiment adopts the front-end unit collection mode to transmit data via optical fiber, so that there is no longer an electrical connection between the tester and the system voltage.

[0065] like Figure 5 The hardware architecture diagram of the pre-stage unit of the primary frequency modulation test shown in the figure shows that the pre-stage acquisition system adopts the system architecture of a single FPGA controller; the analog voltage and current are passed through the PT, and the current uses a non-contact current clamp to convert the secondary current into a small voltage signal, which is collected by the AD conversion module, and after being processed by the FPGA, it is output through the FT3 optical fiber port. The pre-stage acquisition system is battery-powered and can be arranged locally, which is convenient for on-site installation. The FT3 serial optical fiber output adopts Manchester encoding and utilizes the characteristics of delay stability and synchronous transmission to achieve multi-interval synchronous acquisition. The test host synchronously collects three-way optical fiber digital signals and the voltage signals collected inside the test host and performs synchronous processing. At the same time, the test host collects the control signal of the fast power regulation device from the data bus through the Ethernet interface to provide data support for the subsequent primary frequency modulation test.

[0066] As one or more implementation methods, in step 4, after collecting the voltage data of the voltage frequency source and the current and voltage data of the three grid-connected points, the real-time frequency of the voltage frequency source and the voltage of the three grid-connected points is calculated respectively, and after obtaining the actual frequency of each point, the current and voltage data are interpolated twice and then Fourier transformed to improve the calculation accuracy of the Fourier transform. The voltage and current Fourier transform adopts a recursive algorithm to improve the resolution of the real-time power calculation, and the real-time power resolution can reach 1ms, while not increasing the calculation amount of the Fourier integral.

[0067] As one or more implementation methods, in step 5, during a frequency modulation test, a real-time wave recording method is used to display the test results, with dual screens. The first screen displays multiple parameters according to time, with the start time of a frequency modulation test as the starting point, and the real-time wave recording records the real-time waveforms of current and voltage at each test point, and at the same time, the real-time frequency curve, real-time amplitude curve of the voltage frequency source and the real-time power of the three grid-connected points of new energy are recorded according to the time axis. The second screen is displayed according to the relationship between the system frequency and the real-time power of each grid-connected point, accurately reflecting the response capability of the new energy power station to the system frequency change.

[0068] As one or more implementation methods, in step six, when the new energy power station performs a frequency modulation test, there are many test items, so a test report needs to be automatically generated. The test process takes a long time, and the manual workload of selecting the data required for the report from the test data is very huge, so the wave recording method is adopted, and the wave recording method adopts two methods: frequency wave recording and power mutation wave recording. The wave recording data is intercepted according to different test items, and the data is converted into a waveform and added to the test report.

[0069] The frequency recording mode is frequency over-limit, that is, the frequency reaches the adjustment value. The power mutation recording adopts real-time power change recording, that is, Δp=|[p(t)-p(tT)]–[p(tT)-p(t-2T)]|, p is the real-time power, and T is the cycle time calculated according to the real-time frequency. When Δp is greater than the set value, recording is performed.

[0070] This embodiment adopts an integrated design concept, making the voltage frequency source and the multi-grid point test data analysis system into one device, sharing the same software and interface. During the test, a single person and a single device can complete the test, reducing the test difficulty for the tester; the frequency self-calibration method is used to improve the accuracy of the output frequency, and the output frequency accuracy can reach 0.0001Hz to meet the test requirements of primary frequency modulation; the multi-grid point data distribution collection, optical fiber uploading method, and the FT3 synchronous transmission protocol of the electronic transformer are used for uploading. The problem that the small voltage signal of the non-contact current sensor cannot be transmitted over a long distance is solved. At the same time, the local acquisition of battery power supply method also solves the problem that there is an electrical connection between the real-time current voltage and current signal of the system and the virtual test signal issued by the test system.

[0071] The real-time data calculation of voltage and current in this embodiment adopts recursive Fourier integration, which can achieve high resolution of power signal without increasing the data calculation amount of the test system, and can quickly reflect the change of real-time power; dual-screen display is adopted to realize multi-dimensional testing, one time dimension can test the change relationship between various electrical parameters along the time axis, and the other is the frequency dimension which can accurately reflect the change relationship between frequency and real-time power; according to the real-time frequency and power changes, the waveform is recorded and the test report is automatically generated, which reduces the test time of test personnel to find the change process data in a large amount of test data and reduces the test workload.

[0072] Embodiment 2

[0073] Embodiment 2 of the present invention introduces a primary frequency modulation field test system for a new energy system.

[0074] A primary frequency modulation field test system for a new energy system, comprising:

[0075] An acquisition module configured to determine a field test item for primary frequency regulation of a new energy system;

[0076] A correction module, which is configured to obtain the three-phase voltage and output frequency of the new energy system and perform frequency self-calibration of the new energy system;

[0077] A calculation module is configured to obtain the real-time voltage of the voltage-frequency source and the grid-connected point voltage, and calculate the real-time frequency of the new energy system in combination with the self-calibrated frequency;

[0078] A wave recording module, which is configured to perform real-time wave recording of a frequency modulation test of a new energy system according to the obtained real-time frequency, and obtain wave recording data;

[0079] The test module is configured to intercept the recorded data according to the determined different test items, automatically generate a test report, and complete a frequency modulation field test of the new energy system.

[0080] The detailed steps are the same as the primary frequency regulation on-site test method of the new energy system provided in Example 1, and will not be repeated here.

[0081] Embodiment 3

[0082] Embodiment 3 of the present invention provides a computer-readable storage medium.

[0083] A computer-readable storage medium stores a program, which, when executed by a processor, implements the steps of the primary frequency modulation on-site testing method of a new energy system as described in Embodiment 1 of the present invention.

[0084] The detailed steps are the same as the primary frequency regulation on-site test method of the new energy system provided in Example 1, and will not be repeated here.

[0085] Embodiment 4

[0086] A fourth embodiment of the present invention provides an electronic device.

[0087] An electronic device comprises a memory, a processor and a program stored in the memory and running on the processor, wherein when the processor executes the program, the steps in the primary frequency modulation on-site test method of the new energy system as described in the first embodiment of the present invention are implemented.

[0088] The detailed steps are the same as the primary frequency regulation on-site test method of the new energy system provided in Example 1, and will not be repeated here.

[0089] Embodiment 5

[0090] Embodiment 5 of the present invention provides a computer program product.

[0091] A computer program product includes software codes, wherein the program in the software codes executes the steps in the primary frequency modulation on-site testing method of a new energy system as described in the first embodiment of the present invention.

[0092] The detailed steps are the same as the primary frequency regulation on-site test method of the new energy system provided in Example 1, and will not be repeated here.

[0093] The above description is only a preferred embodiment of the present embodiment and is not intended to limit the present embodiment. For those skilled in the art, the present embodiment may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present embodiment shall be included in the protection scope of the present embodiment.

Claims

1. A method for testing primary frequency modulation on-site of a new energy system, characterized in that: include: Determine the primary frequency regulation on-site test items for new energy systems; Obtain the three-phase voltage and output frequency of the new energy system and perform frequency self-calibration of the new energy system; Obtain the real-time voltage of the voltage and frequency source and the voltage at the grid connection point, and calculate the real-time frequency of the new energy system by combining the frequency after self-calibration; According to the obtained real-time frequency, real-time recording of a frequency modulation test of a new energy system is performed to obtain recording data; The recorded data is intercepted according to the determined different test items, and a test report is automatically generated to complete a frequency modulation field test of the new energy system.

2. A primary frequency modulation field test method for a new energy system as claimed in claim 1, characterized in that: The determined on-site test items for primary frequency regulation of new energy systems include at least dead zone scanning test, frequency step test, frequency disturbance test and anti-disturbance performance test.

3. A primary frequency modulation field test method for a new energy system as claimed in claim 1, characterized in that: The voltage frequency of the new energy system is calculated according to the obtained three-phase voltage, and the obtained voltage frequency is compared with the output frequency to complete the self-calibration of the frequency of the new energy system.

4. A primary frequency modulation field test method for a new energy system as claimed in claim 1, characterized in that: The real-time frequency of the voltage-frequency source and the grid-connected point is calculated according to the voltage data of the voltage-frequency source and the voltage and current data of the grid-connected point; the real-time frequency obtained is subjected to Fourier transformation and recursive operation in sequence to obtain the real-time frequency of the new energy system.

5. A primary frequency modulation on-site testing method for a new energy system as claimed in claim 1, characterized in that: During a frequency modulation test, real-time waveform recording is used to display the test results on two screens. The first screen displays multiple parameters according to time. Taking the start time of a frequency modulation test as the starting point, the real-time waveform recording records the real-time waveforms of current and voltage at each test point. The real-time frequency curve, real-time amplitude curve and real-time power of three new energy grid-connected points of the voltage frequency source are recorded and displayed in sequence according to the time axis. The second screen displays the response capability of the new energy power station to frequency changes according to the relationship between the system frequency and the real-time power of each grid-connected point.

6. A primary frequency modulation field test method for a new energy system as claimed in claim 1, characterized in that: The real-time wave recording adopts frequency wave recording and power mutation wave recording; according to different test items, the wave recording data matching therewith is intercepted, the data is converted into a waveform and added into the test report, so as to complete the automatic generation of the test report.

7. A primary frequency modulation field test system for a new energy system, characterized in that: include: An acquisition module configured to determine a field test item for primary frequency regulation of a new energy system; A correction module, which is configured to obtain the three-phase voltage and output frequency of the new energy system and perform frequency self-calibration of the new energy system; A calculation module is configured to obtain the real-time voltage of the voltage-frequency source and the grid-connected point voltage, and calculate the real-time frequency of the new energy system in combination with the self-calibrated frequency; A wave recording module, which is configured to perform real-time wave recording of a frequency modulation test of a new energy system according to the obtained real-time frequency, and obtain wave recording data; The test module is configured to intercept the recorded data according to the determined different test items, automatically generate a test report, and complete a frequency modulation field test of the new energy system.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the primary frequency regulation field test method of the new energy system as described in any one of claims 1-6 are implemented.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the program, the steps of the primary frequency regulation on-site testing method of the new energy system according to any one of claims 1-6 are implemented.

10. A computer program product comprising software code, characterized in that The program in the software code executes the steps of the primary frequency regulation field test method of the new energy system as described in any one of claims 1-6.

Images