On-site test system and method for broadband measurement system of power system based on multi-machine simultaneous control

Abstract

The invention provides an electric power system broadband measurement system field test system and method based on multi-machine simultaneous control. The system comprises a plurality of electric power system broadband measurement device testers with a 5G communication function and a cloud server. Wherein the cloud server issues an instruction to each power system broadband measuring device tester through a 5G signal, and each power system broadband measuring device tester performs time synchronization through a satellite so as to perform synchronous triggering at the same moment. The tester for the broadband measuring device of the power system is used for outputting an analog quantity signal, a switching value signal, a synchronous phasor signal or a disturbance signal, and is used for simulating different working conditions to test the broadband measuring device of the power system. Based on the 5G communication technology and the multi-machine synchronous output technology, the verification of the broadband measurement system of the power system is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of power systems, and in particular to a field testing system and method for a broadband measurement system of a power system based on multi-machine simultaneous control. Background Art

[0002] With the large-scale grid connection of new energy and the widespread application of high-voltage direct current transmission technology, the application of power electronic equipment in the power grid is becoming more and more extensive. Its prominent feature is that the power grid is showing a trend of power electronics development. The application of a large number of power electronic equipment has injected a large number of interharmonics and high-order harmonic signals into the power grid. Compared with the existing power grid state quantity measured based on power frequency signals, it can no longer meet the needs of power electronic grid operation monitoring. So far, all equipment used in substations, including measurement and control devices, phasor measurement units (PMUs), etc., focus on 50Hz power frequency measurement signals. When sub / supersynchronous oscillation signals and broadband oscillation signals appear in the system, these devices lack corresponding monitoring functions and cannot meet the needs of effective measurement of harmonic and interharmonic signals. Therefore, it is necessary to realize broadband measurement. However, there is currently no broadband measurement system for the overall power system. The existing technical solutions can only test single devices, and the test items are incomplete, and system-level testing cannot be achieved.

[0003] The existing technical conditions cannot realize system-level cascade adjustment of the power system broadband measurement system, and there are the following deficiencies: (1) Only a single device can be tested, and the test items are incomplete. It is impossible to achieve the joint debugging of multiple devices and cannot reflect the actual operation status of the WAMS system (wide area measurement system).

[0004] (2) Long testing time. With the increase of business access, the required testing time will be longer according to the existing technical conditions. Summary of the invention

[0005] Therefore, in view of the defects and shortcomings of the prior art, in order to ensure that the measurement accuracy, monitoring function and monitoring data of the broadband measurement device can meet the measurement index requirements of broadband signals after commissioning, and for the safe and stable operation of the WAMS system, the present invention proposes a field testing device and method for a broadband measurement system of a multi-machine synchronous power system.

[0006] The present invention specifically adopts the following technical solutions: A field test system for broadband measurement of power systems based on multi-machine simultaneous control: It includes multiple power system broadband measurement device testers and cloud servers with 5G communication functions; wherein the cloud server sends instructions to each power system broadband measurement device tester through 5G signals, and each of the power system broadband measurement device testers is synchronized through satellite so as to be synchronously triggered at the same time.

[0007] The power system broadband measurement device tester is used to output analog quantity signals, switch quantity signals, synchronous phasor signals, or disturbance signals, and is used to simulate different working conditions to test the power system broadband measurement system.

[0008] Furthermore, the power system broadband measurement device tester is deployed in a substation or power plant where the power system broadband measurement device is installed, and all testers are triggered synchronously to apply analog quantities, switch quantities and disturbances in the test scheme to each power system broadband measurement device.

[0009] Furthermore, the synchronization of each of the above-mentioned power system broadband measurement device testers is achieved by forming a unified clock synchronization environment through multiple FPGA communications: all plug-ins work under a unified clock source and control multiple plug-in outputs at the same time to ensure consistent synchronization between multiple plug-ins, thereby achieving synchronized output of the power system broadband measurement device tester.

[0010] Furthermore, an online real-time compensation method for the clock crystal frequency is used to ensure the synchronous output of the testers of the broadband measurement devices of each power system: the FPGA counts the crystal frequency and obtains its current count value and crystal frequency in real time; and a clock feedback control loop is used to achieve clock synchronization between time nodes.

[0011] Furthermore, the clock feedback control loop includes: a satellite receiving module, a frequency measurement module, a time difference measurement module, a filtering module, a control module and a frequency adjustment module connected to each other: The satellite receiving module is used to receive the satellite 1pps time synchronization signal via the antenna and transmit it to the frequency measurement module; The frequency measurement module uses the frequency measurement method to measure the frequency; the satellite 1pps time synchronization signal is used as the standard signal, and the 320MHz clock after the crystal oscillator outputs 25MHz and then multiplies by the FPGA digital PLL is used as the measured signal; the measured value is output to the filter module and the time difference measurement module; The time difference measurement module uses satellite time synchronization to obtain the crystal oscillator time difference ΔT; The phase error between the crystal oscillator and the master time node is calculated as:

[0012] Where f0 is the nominal frequency of the system; the error θ between the acquired phase and the crystal oscillator is used as the observed quantity for clock feedback control; The filtering module uses Kalman filtering to filter and estimate the clock state, and transmits the frequency prediction value to the control module to calculate the adjustment value and input it into the frequency adjustment module to adjust the frequency of the crystal oscillator; Furthermore, the filtering module adopts a first-order FLL-assisted PLL filter.

[0013] Further, the frequency adjustment module includes a DAC chip and a crystal oscillator, which is used to adjust the frequency of the crystal oscillator by outputting a control voltage from the DAC; And, the test method based on the above system: Data interaction between cloud servers and multiple power system broadband measurement device testers is achieved through cloud-edge collaboration: The test data is divided into two parts: the edge and the cloud. The edge completes the preprocessing of the test data of a single station, and the cloud completes the aggregation and fusion of the preprocessed data of multiple stations; The cloud server sends data to multiple power system broadband measurement device testers through 5G communication and data distribution.

[0014] And, the synchronization method based on the above system: First, a high-precision time synchronization network based on 5G and satellite, air interface timing technology and IRIG-B time code are used to perform high-precision timing on the power system broadband measurement device tester, so that the power system broadband measurement device tester can obtain UTC absolute time information; Then, the tester of the power system broadband measurement device outputs the fault simulation quantity, and encapsulates the fault current output information and the UTC absolute time into a synchronous data message.

[0015] Furthermore, an independent 5G slice network is used to transmit synchronous datagrams, and the sampling point interpolation synchronization method is used to perform data synchronization processing using UTC absolute time information to ensure the synchronization of the output data.

[0016] Compared with the prior art, the present invention and its preferred solution have the following outstanding advantages: Provides multi-machine synchronous output technology based on synchronous clock synchronous triggering, using the second pulse clock of the clock signal as the time reference, and can generate nanosecond timing pulses through FPGA and high-precision constant temperature crystal oscillator. Use the second pulse timing to achieve synchronous output of multiple testers.

[0017] Based on cloud-edge collaborative multi-machine collaborative control technology, the master station test software on the cloud platform distributes test data to different on-site power system broadband measurement device testers through 5G transmission links according to different test plans; multiple power system broadband measurement device testers are synchronized through Beidou; the on-site power system broadband measurement device testers use a unified clock signal to synchronize the output, thereby realizing the test of the power system broadband measurement system. The verification rate can reach 100%, and the time saving rate can reach more than 90%. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments: Figure 1 This is a diagram of the overall architecture of the system according to an embodiment of the present invention.

[0019] Figure 2 The figure is a schematic diagram of a clock synchronization hardware architecture based on FPGA according to an embodiment of the present invention.

[0020] Figure 3 A schematic diagram of a preferred synchronization solution according to an embodiment of the present invention.

[0021] Figure 4 Schematic diagram of the transmission structure of an embodiment of the present invention. DETAILED DESCRIPTION

[0022] Hereinafter, the specific embodiments of the present application will be described in detail with reference to the accompanying drawings. According to these detailed descriptions, those skilled in the art can clearly understand the present application and can implement the present application. Without violating the principles of the present application, the features in the various embodiments can be combined to obtain new implementations, or certain features in certain embodiments can be replaced to obtain other preferred implementations.

[0023] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. 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 "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0024] In order to make the features and advantages of this patent more obvious and easy to understand, the following embodiments are specifically described in detail as follows: like Figure 1As shown, in the basic design provided by the embodiment of the present invention, the field test system of the power system broadband measurement system based on multi-machine co-control is composed of multiple power system broadband measurement device testers with 5G communication functions and a cloud platform. The test host (test master station) and the power system broadband measurement device and the corresponding processing unit are existing devices for realizing broadband measurement, but they cannot achieve high-precision synchronization of multiple sites. The main purpose of the design of the present invention is to solve this problem.

[0025] Among them, the on-site test software of the power system broadband measurement system sends commands to different power system broadband measurement device testers through 5G signals. The power system broadband measurement device testers are synchronized through satellites (Beidou), and all power system broadband measurement device testers are set to be triggered at the same time. The power system broadband measurement device testers can output normal analog signals, switching signals, and synchronous phasor signals, and can also output disturbance signals to different power system broadband measurements, which are used to simulate different working conditions for overall testing of the power system broadband measurement system.

[0026] Based on the basic design of the above solution, the following is a further detailed introduction to the solution of this embodiment: In the first embodiment of the present invention, the cloud platform controls multiple power system broadband measurement device testers to output synchronously through multi-machine collaborative control technology, and the specific implementation method of the hardware is as follows: 1) Consider that the master station test equipment and the power system broadband measurement device tester are composed of a variety of expandable plug-in structures; 2) This embodiment provides a unified clock synchronization environment formed by multiple FPGA communications for the synchronization between expandable plug-ins. It mainly controls the output of multiple plug-ins at the same time to ensure the consistency of synchronization between multiple plug-ins, and controls the synchronization of multiple plug-ins by the control plug-in. There is a synchronous master-slave relationship between each plug-in. All plug-ins work under a unified clock source to achieve synchronous output of multiple plug-ins, thereby achieving synchronous output of the power system broadband measurement device tester.

[0027] Among them, the synchronization accuracy is ensured by using the clock crystal frequency online real-time compensation method to ensure the synchronous output of the tester of each power system broadband measurement device. The specific implementation method is as follows: ① The tester adopts FPGA-based hardware architecture system design. From the time the system is powered on, the FPGA is used to count the crystal frequency and obtain its current count value and crystal frequency in real time; ② A clock feedback control loop consisting of a frequency measurement module, a time difference measurement module, a filtering module, a control module and a frequency adjustment module is used to achieve clock synchronization between time nodes, such as Figure 2 As shown: Frequency measurement module: High-precision frequency measurement is the key to achieve frequency synchronization and clock synchronization. The present invention adopts the frequency measurement method to measure the frequency. The satellite 1pps time synchronization signal is selected as the standard signal, and the 320MHz clock output by the crystal oscillator and multiplied by the FPGA digital PLL is used as the measured signal.

[0028] The frequency measurement module is based on FPGA design, inputs 320MHz clock signal, system low-effective asynchronous reset signal, satellite time synchronization valid signal, GNSS 1pps time synchronization signal, and outputs 28-bit wide frequency measurement value and valid signal.

[0029] Time difference measurement unit: The time difference measurement unit uses Beidou or GPS to obtain the crystal oscillator time difference ΔT. The phase error between the crystal oscillator and the master time node is:

[0030] Where f0 is the nominal frequency of the system. The error θ between the phase obtained by GPS or BeiDou and the crystal oscillator is used as the observed value for clock state estimation.

[0031] Filter module: In order to reduce the impact of clock measurement noise on clock synchronization accuracy, Kalman filter (KF) is used to filter and estimate the clock state. The loop filter unit uses a first-order FLL-assisted PLL filter to ensure that the loop has a sufficiently large frequency pulling capability and a sufficiently high clock output accuracy, and the output is used to adjust the slave node clock.

[0032] Control Module: The control module uses a 50MHz system clock and a system low-valid asynchronous reset signal, inputs a 34-bit filtered frequency prediction value and a valid signal, and inputs 16-bit proportional KP, integral KI and differential KD parameters. These signals are all from the output of VIO to facilitate parameter changes during debugging to achieve the optimal control process; outputs a 16-bit wide DAC digital voltage adjustment value and a valid signal.

[0033] Frequency adjustment module: The frequency adjustment hardware circuit is mainly implemented around the DAC chip and crystal oscillator to complete the DAC output control voltage to adjust the frequency of the crystal oscillator. This module uses a finite state machine to complete the DAC configuration module in the FPGA. The state machine uses a 60MHz system clock and a system low-effective asynchronous reset signal, inputs the 16-bit DAC digital voltage adjustment data and valid signal of the control module, and outputs a DAC configuration completion signal.

[0034] 3) According to the above design, the control plug-in controls multiple sub-plug-ins at the same time, transmits digital messages through the control program and outputs synchronous message information at the same time. The control host hardware uses high-speed, high-reliability programmable logic chips to complete Ethernet control, message sending and receiving processing, data format control, and synchronous control.

[0035] In the second embodiment of the present invention, data interaction between a cloud platform and multiple power system broadband measurement device testers is achieved through cloud-edge collaboration.

[0036] The control method of cloud-edge collaboration is to divide the test data into two parts: the edge and the cloud. The edge completes the test data preprocessing of a single station, and the cloud completes the aggregation and fusion of preprocessed data from multiple stations.

[0037] 1) Install the field test system software of the broadband measurement system for multi-machine simultaneous control of power systems in the cloud platform; The cloud platform sends data to multiple field testers of the power system broadband measurement system through 5G communication and data distribution. The data includes the following: the starting byte position and end value byte position of each data packet required by the data protocol processing unit, the timestamp of each frame message, and the data definition of each channel. The data protocol processing unit decomposes and reassembles the simulation data message according to the parameter information provided by the control platform.

[0038] 2) The tester is connected to the cloud server through the 5G wireless communication function, and the reorganized data packets provided by the data protocol processing unit are uploaded to the cloud server wirelessly, and finally sent to the on-site test terminal.

[0039] 3) Cloud platform software uses Web pages and Java technology to achieve remote control under different operating systems. The remote control system is realized by remote monitoring terminal, long-distance data transmission, and on-site equipment monitoring and control. The remote control system model is as follows: Figure 4 shown.

[0040] In the third preferred embodiment of the present invention, based on the above hardware design of the synchronization scheme, the present invention also provides a further design of the synchronization mode of the field tester of the power system broadband measurement system, such as Figure 3 As shown: ① Use the high-precision time synchronization network based on 5G and Beidou, air interface timing technology and IRIG-B time code to perform high-precision timing on the power system broadband measurement system field tester, and the power system broadband measurement system field tester obtains UTC absolute time information.

[0041] ② Secondly, the field tester of the power system broadband measurement system outputs the fault simulation quantity and encapsulates the fault current output information and UTC absolute time into a synchronous data message.

[0042] ③ Use independent 5G network slices for synchronous datagram transmission. In particular, separate 5G network slices are used for services that have strict requirements on latency, such as testing of broadband measurement devices in power systems.

[0043] ④ Through the sampling point interpolation synchronization method, the UTC absolute time information is used for data synchronization processing to ensure the synchronization of the output data.

[0044] In summary of the above design schemes, in a fourth embodiment of the present invention, a specific operation step of implementing cascade adjustment of a broadband measurement system based on the design of the present invention is provided as follows: (1) A power system broadband measurement device tester is deployed in each substation / power plant where a power system broadband measurement device (the existing device is generally a synchronous phasor measurement device) is installed.

[0045] (2) A host system is deployed in the test center, and the field test system software of the multi-machine simultaneous control power system broadband measurement system is installed on the host system.

[0046] (3) The power system broadband measurement device tester is synchronized through the Beidou timing device in the station or the Beidou timing function of the power system broadband measurement device tester itself.

[0047] (4) Configure 5G communication for each power system broadband measurement device tester.

[0048] (5) After the 5G communication configuration of each power system broadband measurement device tester is completed, each tester is connected to the test master station through the cloud platform.

[0049] (6) The test master station prepares a test plan based on the actual on-site conditions.

[0050] (7) The test master station sends the test plan to the test instruments of each power system broadband measurement device through the cloud platform and 5G communication.

[0051] (8) Set the synchronization trigger time in the test master station.

[0052] (9) Each tester is triggered synchronously according to the synchronous trigger time, and the analog quantity, switch quantity and disturbance in the test scheme are applied to each power system broadband measurement device.

[0053] (10) The power system broadband measurement device sends the received analog quantity to the power system broadband measurement processing unit in the form of a message.

[0054] (11) The broadband measurement processing unit sends the received relevant message information to the test master station.

[0055] (12) The test master station automatically performs comparison calculations based on the received message information and outputs the test results.

[0056] Based on the above design, in the fifth preferred embodiment of the present invention, it is also possible to combine the test case automatic generation technology, according to the actual configuration of the broadband measurement device of the power system to be tested on site and the actual test requirements on site, according to different test standards and test items, to automatically generate test cases based on the actual site.

[0057] And provide strategy consistency comparison: through the logic strategy set by the test host, the power system broadband measurement device tester specifically executes it to different power system broadband measurement devices, and the strategy confirmed after the actual collection of the device "execution case" is verified is compared with the logic strategy set by the test host, and then analyzed, and the test report is automatically generated. In this way, the power system broadband measurement system is automatically verified and a report is generated without manual intervention.

[0058] The above is a preferred embodiment of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

[0059] This patent is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of field test systems and methods for broadband measurement systems of power systems based on multi-machine simultaneous control under the inspiration of this patent. All equal changes and modifications made according to the scope of the patent application of the present invention should be covered by this patent.

Claims

1. A field test system for broadband measurement of power systems based on multi-machine simultaneous control. Features: It includes multiple power system broadband measurement device testers and cloud servers with 5G communication functions; wherein the cloud server sends instructions to each power system broadband measurement device tester through a 5G signal, and each of the power system broadband measurement device testers is synchronized through a satellite to be synchronously triggered at the same time; The power system broadband measurement device tester is used to output analog quantity signals, switch quantity signals, synchronous phasor signals, or disturbance signals, and is used to simulate different working conditions to test the power system broadband measurement system.

2. According to claim 1, the field test system for the broadband measurement system of the power system based on multi-machine simultaneous control, Features: The power system broadband measurement device tester is deployed in a substation or power plant where the power system broadband measurement device is installed. All testers are triggered synchronously to apply the analog quantity, switch quantity and disturbance in the test scheme to each power system broadband measurement device.

3. According to claim 1, the field test system for the broadband measurement system of the power system based on multi-machine simultaneous control, Features: The synchronization of each of the above-mentioned power system broadband measurement device testers is achieved by forming a unified clock synchronization environment through multiple FPGA communications: all plug-ins work under a unified clock source and control multiple plug-in outputs at the same time to ensure consistency in synchronization between multiple plug-ins, thereby achieving synchronized output of the power system broadband measurement device tester.

4. According to claim 3, the field test system for the broadband measurement system of the power system based on multi-machine simultaneous control, Features: The clock crystal frequency is compensated online in real time to ensure the synchronous output of the testers of the broadband measurement devices of each power system: the FPGA counts the crystal frequency and obtains its current count value and crystal frequency in real time; and a clock feedback control loop is used to achieve clock synchronization between time nodes.

5. According to claim 4, the field test system for the broadband measurement system of the power system based on multi-machine simultaneous control, Features: The clock feedback control loop includes: a satellite receiving module, a frequency measurement module, a time difference measurement module, a filtering module, a control module and a frequency adjustment module connected to each other: The satellite receiving module is used to receive the satellite 1pps time synchronization signal via the antenna and transmit it to the frequency measurement module; The frequency measurement module uses the frequency measurement method to measure the frequency; the satellite 1pps time synchronization signal is used as the standard signal, and the 320MHz clock after the crystal oscillator outputs 25MHz and then multiplies by the FPGA digital PLL is used as the measured signal; the measured value is output to the filter module and the time difference measurement module; The time difference measurement module uses satellite time synchronization to obtain the crystal oscillator time difference ΔT; The phase error between the crystal oscillator and the master time node is calculated as: In the formula, f 0 is the nominal frequency of the system; the error θ between the acquired phase and the crystal oscillator is used as the observed quantity of clock feedback control; The filtering module uses Kalman filtering to filter and estimate the clock state, and transmits the frequency prediction value to the control module to calculate the adjustment value and input it into the frequency adjustment module to adjust the frequency of the crystal oscillator.

6. The field test system for the broadband measurement system of the power system based on multi-machine simultaneous control according to claim 5, Features: The filtering module adopts a first-order FLL-assisted PLL filter.

7. The field test system for the broadband measurement system of the power system based on multi-machine simultaneous control according to claim 5, Features: The frequency adjustment module includes a DAC chip and a crystal oscillator, and is used to adjust the frequency of the crystal oscillator by outputting a DAC control voltage.

8. A testing method for a field testing system of a power system broadband measurement system based on multi-machine simultaneous control according to any one of claims 1 to 7, Features: Data interaction between cloud servers and multiple power system broadband measurement device testers is achieved through cloud-edge collaboration: The test data is divided into two parts: the edge and the cloud. The edge completes the preprocessing of the test data of a single station, and the cloud completes the aggregation and fusion of the preprocessed data of multiple stations; The cloud server sends data to multiple power system broadband measurement device testers through 5G communication and data distribution.

9. A synchronization method for a field test system of a power system broadband measurement system based on multi-machine simultaneous control according to any one of claims 1 to 7, Features: First, a high-precision time synchronization network based on 5G and satellite, air interface timing technology and IRIG-B time code are used to perform high-precision timing on the power system broadband measurement device tester, so that the power system broadband measurement device tester can obtain UTC absolute time information; Then, the tester of the power system broadband measurement device outputs the fault simulation quantity, and encapsulates the fault current output information and the UTC absolute time into a synchronous data message.

10. The synchronization method of the field test system of the power system broadband measurement system based on multi-machine simultaneous control according to claim 9, Features: An independent 5G slice network is used to transmit synchronous datagrams, and the sampling point interpolation synchronization method is used to perform data synchronization processing using UTC absolute time information to ensure the synchronization of output data.

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