Power plant fault recording system supporting broadband and multi-type signal measurement
By designing a faulty wave recording system that supports wide bands, the problem that traditional systems cannot collect high-frequency signals and adapt to ungrounded systems is solved, recording high-frequency signals and optical CT currents is realized, and the power frequency of DC signals is reduced Interference provides more accurate failure analysis data.
Patent Information
- Application Number
- CN202420336561.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-23
- Publication Date
- 2025-01-17
- Estimated Expiration
- 2034-02-23
AI Technical Summary
Traditional fault recording systems cannot collect and analyze high-frequency signals, and cannot adapt to generator systems that are not grounded or grounded with high resistance. There is also a problem of industrial frequency interference when collecting DC signals, resulting in insufficient and inaccurate fault analysis data.
A fault recording system that supports wideband and various types of signal measurements is designed, including high-frequency signals, power frequency signals and DC signals in-place collectors, using high-frequency bandpass filters, power frequency notchers and independent The acquisition circuit can collect signals in the range of 1MHz-100MHz and 1kHz-10MHz, and send data to the host of the faulty wave recording device for analysis through the MMS, SV, and GOOSE networks.
It realizes the acquisition and analysis of high-frequency signals, supports the recording of optical CT current, reduces the power frequency interference of DC signals, and provides richer and more accurate fault analysis data.
Smart Images
Figure CN222365048U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a power plant fault recording system which supports wide-band and multi-type signal measurement. Background Art
[0002] The fault recording system can record the changes in the electrical parameters of the power system before and after a large disturbance occurs, as well as the actions of the relay protection and safety automatic devices, to help with disturbance analysis. It is an important secondary system in a power station. At present, the traditional fault recording system only collects, analyzes and displays the power frequency voltage and current signals, DC signals and input signals collected by conventional PT / CT. As the topology of the power system becomes increasingly complex and the need for intelligent operation and maintenance of the power system increases, the traditional fault recording system has shortcomings and problems, which are mainly manifested in:
[0003] 1) The acquisition unit used in the traditional fault recording system only supports the acquisition of signals near the power frequency range. It cannot collect signals containing high-frequency components such as partial discharge or traveling waves. Therefore, it is impossible to collect high-frequency signals such as partial discharge or traveling waves generated by the system before or at the time of the fault. These high-frequency signals contain rich fault information. For example, the type of fault can be determined by the waveform characteristics of the partial discharge signal, and the specific location of the fault can be determined by the time difference between the first and second wave head points of the traveling wave waveform. The traditional fault recording system cannot achieve the above analysis.
[0004] 2) The traditional fault recording system can only process the signal collected by the conventional CT / PT. For the generator set system that is not grounded, grounded by high resistance, or grounded by the grounding transformer secondary load resistance, the zero sequence current is very small during a single-phase grounding fault, and the primary value is generally less than 10A. There is a large dead zone when using the traditional CT for current measurement. At this time, it is usually necessary to use optical CT to collect the current and provide it to the protection device to improve the accuracy of small current measurement and increase the reliability and sensitivity of the protection device. When the protection device uses the current collected by the optical CT and the fault recording system uses the current collected by the conventional CT, there will be a problem that the recording data of the two systems do not correspond. At this time, the fault recording system cannot provide effective data support for accident analysis.
[0005] 3) Traditional fault recording systems usually do not effectively remove power frequency signals when collecting DC signals, resulting in large fluctuations in the calculated effective value of the DC quantity when there is a large power frequency interference. The DC waveform in the recording file also has obvious superposition of the power frequency interference waveform. Utility Model Content
[0006] The purpose of the utility model is to provide a power plant fault recording system that supports wide-band and multi-type signal measurement. Compared with traditional fault recording systems, it has a wider frequency measurement range and supports more types of signal measurement, which can provide richer data support for fault analysis.
[0007] In order to achieve the above purpose, the solution of the utility model is:
[0008] A power plant fault recording system supporting wide-band and multi-type signal measurement comprises a high-frequency signal local collector, a power frequency signal local collector, a direct current signal local collector, an input signal local collector, a fault recording device host and a workstation; the high-frequency local collector is connected to a high-voltage overhead line or a high-voltage cable, and its output data is sent through a station control layer MMS network; the power frequency signal local collector and the direct current signal local collector are connected to a generator end, and their output data are sent through a process layer SV network; the input signal local collector is connected to a generator end, and its output data is sent through a process layer GOOSE network; the fault recording device host receives the waveform or real-time data output by each collector on the MMS network, the SV network and the GOOSE network and analyzes them, and the analysis results are sent to the workstation for web display.
[0009] The above-mentioned high-frequency signal on-site collector includes a high-frequency partial discharge signal acquisition circuit, a high-frequency traveling wave signal acquisition circuit and a first file packaging module; wherein, the high-frequency partial discharge signal acquisition circuit includes a partial discharge current sensor, a partial discharge bandpass filter, a partial discharge modulation circuit, a partial discharge ADC, and a partial discharge integrator connected in sequence from input to output, and the high-frequency traveling wave signal acquisition circuit includes a traveling wave current sensor, a traveling wave bandpass filter, a traveling wave modulation circuit, a traveling wave ADC, and a traveling wave integrator connected in sequence from input to output, and the output ends of the high-frequency partial discharge signal acquisition circuit and the high-frequency traveling wave signal acquisition circuit are both connected to the input end of the first file packaging module, and the first file packaging module outputs a comtrade format waveform file to the station control layer MMS network.
[0010] The cut-off frequency of the above-mentioned partial discharge band-pass filter can be adjusted in the range of 1MHz-100MHz, and the cut-off frequency of the traveling wave band-pass filter can be adjusted in the range of 1kHz-10MHz.
[0011] The above-mentioned on-site power frequency signal collector includes a power frequency voltage and current signal acquisition circuit, an optical CT signal acquisition circuit, a second ADC and a second file packaging module; wherein the power frequency voltage and current signal acquisition circuit includes a first bandpass filter and a modulation circuit connected in sequence from input to output, and the first bandpass filter is used to input the power frequency voltage and current signal; the optical CT signal acquisition circuit includes a phase modulator, a first coupler, a light detector, a modulation and demodulation electronic circuit connected in sequence from input to output, and also includes a light source and a second coupler connected in sequence, the phase modulator is used to input the optical CT signal, the output end of the second coupler is connected to the input end of the phase modulator, and the output end of the modulation and demodulation electronic circuit is also connected to the input end of the phase modulator; the input ends of the power frequency voltage and current signal acquisition circuit and the optical CT signal acquisition circuit are both connected to the input end of the second ADC, the output end of the second ADC is connected to the input end of the second file packaging module, and the second file packaging module outputs SV analog data to the process layer SV network.
[0012] The above-mentioned DC signal on-site collector includes an industrial frequency trap, a modulation circuit, a third ADC, and a third file packaging module connected in sequence from input to output. The industrial frequency trap is used to input DC mA, DC mV and DC voltage, and the third file packaging module outputs SV analog data to the process layer SV network.
[0013] After adopting the above scheme, the utility model has the following characteristics:
[0014] (1) The system provided by the utility model supports the acquisition of high-frequency signals, and can acquire partial discharge signals with a frequency range of 1MHz-100MHz and traveling wave signals with a frequency range of 1kHz-10MHz. The collected partial discharge signals can be used to analyze the type of fault, and the traveling wave signals can be used to locate the fault point. Compared with the traditional fault recording system, this system can provide richer data support for fault analysis.
[0015] (2) The system provided by the utility model supports analysis and recording of the industrial frequency current sampled by the optical CT, and can be used in conjunction with a protection device that uses the optical CT sampled current as the protection current, thereby making up for the deficiency that the traditional fault recording system cannot adapt to such protection devices.
[0016] (3) The DC signal of the system provided by the utility model is processed by power frequency notch, which can effectively reduce the power frequency interference on the DC signal. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a communication topology diagram of a power plant fault recording system supporting wide-band and multi-type signal measurement in the utility model;
[0018] Figure 2This is a schematic diagram of the installation of the local collector of medium and high frequency signals of the utility model;
[0019] Figure 3 It is a structural schematic diagram of the local collector of medium and high frequency signals of the utility model;
[0020] Figure 4 It is a structural schematic diagram of the local power frequency signal collector in the utility model;
[0021] Figure 5 It is a structural schematic diagram of a DC signal local collector in the utility model. DETAILED DESCRIPTION
[0022] The technical solution and beneficial effects of the present utility model will be described in detail below with reference to the accompanying drawings.
[0023] The utility model provides a power plant fault recording system supporting wide-band and multi-type signal measurement, comprising a high-frequency signal local collector, an industrial frequency signal local collector, a direct current signal local collector, an input signal local collector, a fault recording device host and a workstation, wherein the high-frequency local collector is connected to a high-voltage overhead line or a high-voltage cable, and its output data is sent through a station control layer MMS network; the industrial frequency signal local collector and the direct current signal local collector are connected to a generator end, and their output data are sent through a process layer SV network; the input signal local collector is connected to a generator end, and its output data is sent through a process layer GOOSE network; the fault recording device host receives waveforms or real-time data output by each collector on the MMS network, the SV network and the GOOSE network respectively, and the results are sent to the workstation for web display.
[0024] The high-frequency signal on-site collector can collect high-frequency partial discharge signals and high-frequency traveling wave signals at the same time, and the partial discharge signals and traveling wave signals have independent collection loops. After the high-frequency signal enters the collector, it passes through a bandpass filter with adjustable cutoff frequency, a modulation circuit, an ADC, an integrator, and a file packaging module in sequence. The integrator is responsible for integrating the signal for a period of time and outputting the integration result to the file packaging module, which integrates it into a comtrade format waveform file and outputs it to the station control layer MMS network. The cutoff frequencies of the partial discharge filter and the traveling wave filter of the high-frequency signal on-site collector can be adjusted independently, wherein the cutoff frequency of the partial discharge filter can be adjusted in the range of 1MHz-100MHz, and the cutoff frequency of the traveling wave filter can be adjusted in the range of 1kHz-10MHz.
[0025] The power frequency signal local collector can simultaneously collect the power frequency signal output by the conventional CT / PT and the power frequency current signal output by the optical CT. The conventional CT / PT signal collection channel and the optical CT signal collection channel are independent of each other.
[0026] The DC signal local collector supports the collection of mA, mV and DC voltage directly. The collector contains a power frequency trap, which can effectively remove power frequency signal interference and improve signal quality.
[0027] The fault recording system proposed in the utility model is implemented as follows Figure 1 shown.
[0028] The fault recording system includes a high-frequency signal on-site collector, a power frequency signal on-site collector, a DC signal on-site collector, an input signal on-site collector, a fault recording device host and a workstation. The entire system includes four networks, namely the station control layer MMS network, the process layer SV network, the process layer GOOSE network and the timing network. Among them, the high-frequency signal on-site collector is mounted on the MMS network and outputs waveform files in comtrade format; the power frequency signal on-site collector and the DC signal on-site collector are mounted on the process layer SV network and output real-time analog data; the input signal on-site collector is mounted on the process layer GOOSE network and outputs real-time switch data; the fault recording host is mounted on the MMS, SV, and GOOSE networks at the same time to receive the waveforms or data generated by each collection unit, and after sorting and analyzing, it is sent to the workstation for web display. Each component unit is mounted on the timing network to receive the timing signal of the timing device.
[0029] The utility model comprises the following steps during specific implementation:
[0030] (1) Figure 2 As shown, the high-frequency signal on-site collector is connected to the high-voltage overhead line and the high-voltage cable. For the high-voltage overhead line, a collector is set near the busbar, and traveling wave current sensors are installed on the three phases of the overhead line. The output of each phase sensor is connected to the traveling wave collection channel of the high-frequency signal on-site collector in turn. For the high-voltage cable, multiple groups of collectors are set at the ends of the cable and the middle joint of the cable, and partial discharge current sensors are installed outside the grounding wire of the cable shield at various locations. The sensor output is connected to the partial discharge collection channel of the high-frequency signal on-site collector.
[0031] (2) The internal structure of the high-frequency signal local collector is as follows: Figure 3 As shown. The collector has independent partial discharge and traveling wave signal acquisition circuits. After high-frequency partial discharge and traveling wave signals enter their respective acquisition channels, they pass through their respective bandpass filters, modulation circuits, ADCs, integrators, and file packaging modules in sequence. The file packaging module packages data in comtrade format to form a waveform file for uploading. The site should set the appropriate partial discharge and traveling wave acquisition frequency ranges based on actual working conditions and theoretical calculations, that is, set the cutoff frequency ranges of partial discharge and traveling wave bandpass filters respectively.
[0032] (3) The installation position of the power frequency signal local collector is similar to that of the traditional fault recording system. Its internal structure is as follows: Figure 4 As shown, there is an independent circuit inside the collector, which can process conventional CT / PT input signals and optical CT input signals at the same time. The processing of conventional CT / PT input signals is similar to that of traditional fault recording systems. The processing flow for optical CT input signals is as follows: the light source generates an optical signal; the coupler transmits the optical signal generated by the light source to the phase modulator, and transmits the optical signal input from the optical CT to the optical detector; the phase modulator modulates the optical signal in the system to avoid low-frequency noise interference; the optical detector receives the optical signal transmitted by the coupler, converts it into an electrical signal and sends it to the modulation and demodulation electronic circuit for calculation. The calculation result is input into the ADC for analog-to-digital conversion and then output by the file packaging module.
[0033] (4) The installation position of the DC signal local collector is similar to that of the traditional fault recording system. Its internal structure is as follows: Figure 5 As shown, compared with traditional DC signal acquisition, this collector adds a power frequency notch module on the signal input side, which can effectively reduce power frequency interference and improve the accuracy of DC quantity acquisition.
[0034] (5) The installation position and internal structure of the local input signal collector are similar to those of the traditional fault recording system.
[0035] The above embodiments are only for illustrating the technical idea of the present utility model, and cannot be used to limit the protection scope of the present utility model. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present utility model shall fall within the protection scope of the present utility model.
Claims
1. A power plant fault recording system supporting wide-band and multi-type signal measurement, characterized in that: It includes a high-frequency signal local collector, a power frequency signal local collector, a DC signal local collector, an input signal local collector, a fault recording device host and a workstation; the high-frequency local collector is connected to the high-voltage overhead line or high-voltage cable, and its output data is sent through the station control layer MMS network; the power frequency signal local collector and the DC signal local collector are connected to the generator end, and their output data are sent through the process layer SV network; the input signal local collector is connected to the generator end, and its output data is sent through the process layer GOOSE network; the fault recording device host receives the waveform or real-time data output by each collector on the MMS network, SV network and GOOSE network respectively and analyzes them, and the analysis results are sent to the workstation for web display.
2. A power plant fault recording system supporting wide-band and multi-type signal measurement as claimed in claim 1, characterized in that: The high-frequency signal on-site collector includes a high-frequency partial discharge signal acquisition circuit, a high-frequency traveling wave signal acquisition circuit and a first file packaging module; wherein the high-frequency partial discharge signal acquisition circuit includes a partial discharge current sensor, a partial discharge bandpass filter, a partial discharge modulation circuit, a partial discharge ADC, and a partial discharge integrator connected in sequence from input to output, and the high-frequency traveling wave signal acquisition circuit includes a traveling wave current sensor, a traveling wave bandpass filter, a traveling wave modulation circuit, a traveling wave ADC, and a traveling wave integrator connected in sequence from input to output, and the output ends of the high-frequency partial discharge signal acquisition circuit and the high-frequency traveling wave signal acquisition circuit are both connected to the input end of the first file packaging module, and the first file packaging module outputs a comtrade format waveform file to the station control layer MMS network.
3. A power plant fault recording system supporting wide-band and multi-type signal measurement as claimed in claim 2, characterized in that: The cut-off frequency of the partial discharge band-pass filter can be adjusted in the range of 1 MHz to 100 MHz, and the cut-off frequency of the traveling wave band-pass filter can be adjusted in the range of 1 kHz to 10 MHz.
4. A power plant fault recording system supporting wide-band and multi-type signal measurement as claimed in claim 1, characterized in that: The on-site power frequency signal collector includes a power frequency voltage and current signal collection circuit, an optical CT signal collection circuit, a second ADC and a second file packaging module; wherein the power frequency voltage and current signal collection circuit includes a first bandpass filter and a modulation circuit connected in sequence from input to output, and the first bandpass filter is used to input the power frequency voltage and current signal; the optical CT signal collection circuit includes a phase modulator, a first coupler, a light detector, a modulation and demodulation electronic circuit connected in sequence from input to output, and also includes a light source and a second coupler connected in sequence, the phase modulator is used to input the optical CT signal, and the output end of the second coupler is connected to the input end of the phase modulator; the input ends of the power frequency voltage and current signal collection circuit and the optical CT signal collection circuit are both connected to the input end of the second ADC, the output end of the second ADC is connected to the input end of the second file packaging module, and the second file packaging module outputs SV analog data to the process layer SV network.
5. A power plant fault recording system supporting wide-band and multi-type signal measurement as claimed in claim 1, characterized in that: The DC signal on-site collector includes an industrial frequency trap, a modulation circuit, a third ADC, and a third file packaging module connected in sequence from input to output. The industrial frequency trap is used to input DC mA, DC mV and DC voltage, and the third file packaging module outputs SV analog data to the process layer SV network.