A transformer partial discharge detection device and system

Abstract

The application discloses a transformer partial discharge detection device and system. The application uses a fiber optical heterodyne interference ultrasonic sensing module to collect ultrasonic signals and obtain partial discharge ultrasonic signals when partial discharge occurs in a transformer. A hardware phase demodulation module is used to demodulate the phase of the partial discharge ultrasonic signals and obtain demodulation signals. A multi-channel synchronous data acquisition module is used to acquire the demodulation signals and partial discharge sensing signals collected by a plurality of partial discharge sensors. A sensing signal uploading module is used to upload the demodulation signals and all partial discharge sensing signals to an upper computer in real time, so that a plurality of sensing signals can be acquired in real time for partial discharge detection, and the detection efficiency of the partial discharge of the transformer is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of transformer discharge detection, and in particular to a transformer partial discharge detection device and system. BACKGROUND

[0002] The power transformer is an important equipment in the power system, and its normal operation is of great significance to ensure the safe and stable operation of the power system. The power transformer is mostly an oil-immersed power transformer, which has sufficient electrical strength and excellent mechanical properties in design. However, due to the influence of accidental factors in the manufacturing process, local defects such as bubbles, cracks, suspended conductive particles and electrode burrs are easily generated. These local defects can cause the electric field strength in some areas inside or on the surface of the insulator to be higher than the average electric field strength, resulting in partial discharge in the local area. Partial discharge is an important sign of reflecting the insulation defects of the power transformer. On-line or live detection of the partial discharge of the transformer can help to timely grasp the operation state of the transformer, so that the power system can operate more safely and stably.

[0003] At present, the transformer partial discharge detection device is mainly used to detect the partial discharge generated by the transformer. The commonly used transformer partial discharge detection device mostly adopts a single detection method such as a very high frequency sensor, an ultrasonic sensor or a high-frequency current sensor, which cannot comprehensively reflect the operation state of the transformer by using multiple sensing signals, and it is difficult to sensitively and accurately detect the partial discharge generated by the transformer. Therefore, the research on the combination of multiple sensors for detecting the partial discharge generated by the transformer has been started. However, for the optical fiber ultrasonic sensing system based on heterodyne interference phase demodulation, the phase demodulation of the optical signal is the key to realizing the optical fiber ultrasonic sensing. The software demodulation method used has a high sampling rate, large data volume and minute-level demodulation time, and the real-time performance is poor. In addition, the filter design in the algorithm is difficult, which further increases the data processing pressure of the front end of the multi-channel collection, is not conducive to the real-time sampling of multiple channels, and it is difficult to obtain multiple sensing signals in real time for partial discharge detection, which to some extent limits the detection efficiency of the transformer partial discharge. SUMMARY

[0004] In order to overcome the defects of the prior art, the present application provides a transformer partial discharge detection device and system, which can obtain multiple sensing signals in real time for partial discharge detection, and is beneficial to improve the detection efficiency of the transformer partial discharge.

[0005] In order to solve the above technical problems, in a first aspect, an embodiment of the present application provides a transformer partial discharge detection device, which comprises a fiber-optic heterodyne interference ultrasonic sensing module, a hardware phase demodulation module, a multi-channel synchronous data acquisition module and a sensing signal uploading module.

[0006] The output end of the fiber heterodyne interference ultrasonic sensing module is connected with the input end of the hardware phase demodulation module, the output end of the hardware phase demodulation module is connected with the input end of the multi-channel synchronous data acquisition module, the output end of the multi-channel synchronous data acquisition module is connected with the input end of the sensing signal uploading module, and the output end of the sensing signal uploading module is connected with the host computer;

[0007] The fiber heterodyne interference ultrasonic sensing module is used for collecting ultrasonic signals when partial discharge is generated in the transformer to obtain partial discharge ultrasonic signals.

[0008] The hardware phase demodulation module is used for performing phase demodulation on the partial discharge ultrasonic signals to obtain demodulation signals.

[0009] The multi-channel synchronous data acquisition module is used for acquiring the demodulation signals and partial discharge sensing signals collected by a plurality of partial discharge sensors.

[0010] The sensing signal uploading module is used for uploading the demodulation signals and all the partial discharge sensing signals to the host computer in real time.

[0011] Further, the fiber heterodyne interference ultrasonic sensing module comprises a pump laser, an optical isolator, a wavelength division multiplexer, a plurality of FBG fiber lasers, an isolator, a 1x2 coupler, a delay optical fiber, an acousto-optic modulator, a 2x2 coupler and a balanced photodetector.

[0012] The output end of the pump laser is connected with the input end of the optical isolator, the output end of the optical isolator is connected with the first input end of the wavelength division multiplexer, the first output end of the wavelength division multiplexer is connected with the input end of each FBG fiber laser respectively, the output end of each FBG fiber laser is connected with the second input end of the wavelength division multiplexer, the second output end of the wavelength division multiplexer is connected with the input end of the isolator, the output end of the isolator is connected with the input end of the acousto-optic modulator and the delay optical fiber through the 1x2 coupler, the output ends of the delay optical fiber and the acousto-optic modulator are connected with the input end of the balanced photodetector through the 2x2 coupler, and the output end of the balanced photodetector is connected with the output end of the heterodyne interference ultrasonic sensing module.

[0013] Further, the hardware phase demodulation module comprises a first radio frequency phase detector, a second radio frequency phase detector, a 1:1 power divider, a 90° phase shifter, a first band-pass filter and a second band-pass filter.

[0014] The first input end of the first radio frequency phase detector and the second radio frequency phase detector is connected with the input end of the hardware phase demodulation module, the input end of the 1:1 power divider is connected with the output end of a driver driving the acousto-optic modulator, the output end of the 1:1 power divider is connected with the second input end of the first radio frequency phase detector, the output end of the 1:1 power divider is connected with the second input end of the second radio frequency phase detector through the 90° phase shifter, the output end of the first radio frequency phase detector is connected with the input end of the first band-pass filter, the output end of the second radio frequency phase detector is connected with the input end of the second band-pass filter, and the output ends of the first band-pass filter and the second band-pass filter are connected with the output end of the hardware phase demodulation module.

[0015] Further, the multi-channel synchronous data acquisition module comprises a plurality of digital-to-analog converters, an FPGA controller and a first memory.

[0016] The input end of each digital-to-analog converter is connected with the input end of the multi-channel synchronous data acquisition module, the output end of each digital-to-analog converter is connected with the input end of the FPGA controller, the output end of the FPGA controller is connected with the input end of the first memory, and the output end of the FPGA controller is connected with the output end of the multi-channel synchronous data acquisition module.

[0017] Further, the connection interface between the FPGA controller and all the digital-to-analog converters is a CMOS-LVDS hybrid data interface.

[0018] Further, the sensing signal uploading module comprises a processor and a second memory.

[0019] The input end of the processor is connected with the input end of the sensing signal uploading module, the output end of the processor is connected with the input end of the second memory, and the output end of the processor is connected with the output end of the sensing signal uploading module.

[0020] Further, the connection interface between the sensing signal uploading module and the host computer is a high-speed serial bus interface.

[0021] Further, the partial discharge sensor is a very high frequency sensor, a high frequency current sensor or an ultrasonic sensor.

[0022] In a second aspect, an embodiment of the present application provides a transformer partial discharge detection system, comprising a transformer partial discharge detection device and a host computer.

[0023] The transformer partial discharge detection device is in communication connection with the host computer.

[0024] The host computer comprises:

[0025] a mode selection module configured to determine a plurality of partial discharge sensors according to a partial discharge detection mode selected by a user;

[0026] a parameter configuration module configured to configure parameters of each of the partial discharge sensors, so that the transformer partial discharge detection device uploads a demodulation signal and a plurality of partial discharge sensing signals in real time;

[0027] a signal processing module configured to perform signal processing on the demodulation signal to obtain a stationary signal, and perform fast Fourier transform on the stationary signal to obtain a phase modulation amplitude of the stationary signal.

[0028] Further, the parameter configuration module is specifically configured to retrieve parameters of each of the partial discharge sensors from a sensor characteristic parameter database, and configure parameters of each of the partial discharge sensors according to the parameters of each of the partial discharge sensors.

[0029] Compared with the prior art, the embodiment of the present application has the following beneficial effects:

[0030] By designing the transformer partial discharge detection device, the optical fiber heterodyne interference ultrasonic sensing module is used to collect ultrasonic signals when partial discharge occurs in the transformer to obtain partial discharge ultrasonic signals; the hardware phase demodulation module is used to perform phase demodulation on the partial discharge ultrasonic signals to obtain a demodulation signal; the multi-channel synchronous data acquisition module is used to acquire the demodulation signal and a plurality of partial discharge sensing signals collected by the partial discharge sensors; and the sensing signal uploading module is used to upload the demodulation signal and all the partial discharge sensing signals to an upper computer in real time, so that a plurality of sensing signals can be acquired in real time for partial discharge detection, which is beneficial to improving the detection efficiency of transformer partial discharge. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 FIG. 1 is a structural schematic diagram of a transformer partial discharge detection device according to a first embodiment of the present application;

[0032] Figure 2 FIG. 2 is a structural schematic diagram of an optical fiber heterodyne interference ultrasonic sensing module and a hardware phase demodulation module according to a preferred embodiment of the first embodiment of the present application;

[0033] Figure 3 FIG. 3 is a structural schematic diagram of a multi-channel synchronous data acquisition module according to the preferred embodiment of the first embodiment of the present application. DETAILED DESCRIPTION

[0034] The technical solutions of this invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0035] like Figure 1 As shown, the first embodiment provides a transformer partial discharge detection device, including a fiber optic heterodyne interferometric ultrasonic sensing module 10, a hardware phase demodulation module 20, a multi-channel synchronous data acquisition module 30, and a sensor signal uploading module 40. The output of the fiber optic heterodyne interferometric ultrasonic sensing module 10 is connected to the input of the hardware phase demodulation module 20, the output of the hardware phase demodulation module 20 is connected to the input of the multi-channel synchronous data acquisition module 30, the output of the multi-channel synchronous data acquisition module 30 is connected to the input of the sensor signal uploading module 40, and the output of the sensor signal uploading module 40 is connected to a host computer. The fiber optic heterodyne interferometric ultrasonic sensing module 10 is used to collect ultrasonic signals when partial discharge occurs in the transformer to obtain partial discharge ultrasonic signals. The hardware phase demodulation module 20 is used to demodulate the phase of the partial discharge ultrasonic signals to obtain demodulated signals. The multi-channel synchronous data acquisition module 30 is used to acquire the demodulated signals and the partial discharge sensing signals collected by several partial discharge sensors. The sensor signal uploading module 40 is used to upload the demodulated signals and all partial discharge sensing signals to the host computer in real time.

[0036] As an example, a fiber optic heterodyne interferometric ultrasonic sensing module 10, a hardware phase demodulation module 20, a multi-channel synchronous data acquisition module 30, and a sensor signal uploading module 40 are designed. The output of the fiber optic heterodyne interferometric ultrasonic sensing module 10 is connected to the input of the hardware phase demodulation module 20, the output of the hardware phase demodulation module 20 is connected to the input of the multi-channel synchronous data acquisition module 30, the output of the multi-channel synchronous data acquisition module 30 is connected to the input of the sensor signal uploading module 40, and the output of the sensor signal uploading module 40 is connected to a host computer to obtain a transformer partial discharge detection device.

[0037] A transformer partial discharge detection device is applied. According to the installation requirements of different components, a fiber optic heterodyne interferometric ultrasonic sensing module 10 and several partial discharge sensors are installed. The fiber optic heterodyne interferometric ultrasonic sensing module 10 collects ultrasonic signals when partial discharge occurs in the transformer, obtaining partial discharge ultrasonic signals, which are then transmitted to a hardware phase demodulation module 20. The several partial discharge sensors collect corresponding sensing signals when partial discharge occurs in the transformer, obtaining several partial discharge sensing signals, which are then transmitted to a multi-channel synchronous data acquisition module 30. The hardware phase demodulation module 20 performs phase demodulation on the partial discharge ultrasonic signals, converting the partial discharge signals into... The optical phase change caused by partial discharge is demodulated into a voltage amplitude change, and the waveform of the partial discharge ultrasonic signal is restored to obtain a demodulated signal. The demodulated signal is then transmitted to the multi-channel synchronous data acquisition module 30. The multi-channel synchronous data acquisition module 30 acquires the demodulated signal and several partial discharge sensing signals, and transmits them to the sensor signal uploading module 40. The sensor signal uploading module 40 uploads the demodulated signal and all partial discharge sensing signals to the host computer in real time, so that the host computer can acquire multiple sensing signals in real time and perform partial discharge detection by combining multiple sensing signals. This enables sensitive and accurate detection of partial discharge generated by the transformer, which is beneficial to improving the detection efficiency of transformer partial discharge.

[0038] This embodiment utilizes a fiber optic heterodyne interferometric ultrasonic sensing module 10 and several partial discharge sensors to acquire various sensing signals. A hardware phase demodulation module 20 performs phase demodulation on the partial discharge ultrasonic signals acquired by the fiber optic heterodyne interferometric ultrasonic sensing module 10, reducing the demodulation time from minutes to seconds, effectively shortening the demodulation time. A multi-channel synchronous data acquisition module 30 coordinates the real-time transmission of various sensing signals, and a sensing signal upload module 40 coordinates the real-time uploading of various sensing signals. This enables the real-time acquisition of multiple sensing signals for partial discharge detection, improving the detection efficiency of transformer partial discharge.

[0039] In a preferred embodiment, the fiber optic heterodyne interferometric ultrasonic sensing module 10 includes a pump laser 101, an optical isolator 102, a wavelength division multiplexer 103, several FBG fiber lasers 104, an isolator 105, a 1×2 coupler 106, a delay fiber 107, an acousto-optic modulator 108, a 2×2 coupler 109, and a balanced photodetector 110. The output of the pump laser 101 is connected to the input of the optical isolator 102, the output of the optical isolator 102 is connected to the first input of the wavelength division multiplexer 103, and the first output of the wavelength division multiplexer 103 is connected to each FBG fiber laser. The input terminals of the optical devices are connected, and the output terminal of each FBG fiber laser is connected to the second input terminal of the wavelength division multiplexer 103. The second output terminal of the wavelength division multiplexer 103 is connected to the input terminal of the isolator 105. The output terminal of the isolator 105 is connected to the input terminals of the delay fiber 107 and the acousto-optic modulator 108 respectively through a 1×2 coupler 106. The output terminals of the delay fiber 107 and the acousto-optic modulator 108 are both connected to the input terminal of the balanced photodetector 110 through a 2×2 coupler 109. The output terminal of the balanced photodetector 110 is connected to the output terminal of the fiber heterodyne interferometric ultrasonic sensing module 10.

[0040] As an example, several FBG fiber lasers 104, such as four FBG-FLs, are selected to design the fiber heterodyne interferometric ultrasonic sensing module 10. A schematic diagram of the fiber heterodyne interferometric ultrasonic sensing module 10 is shown below. Figure 2 As shown. In Figure 2 In this configuration, the output of pump laser 101 is connected to the input of 980nm optical isolator 102. The output of 980nm optical isolator 102 is connected to the first input of 980 / 1550 wavelength division multiplexer 103. The first output of 980 / 1550 wavelength division multiplexer 103 is connected to the inputs of four FBG-FLs. The output of each FBG-FL is connected to the second input of 980 / 1550 wavelength division multiplexer 103. 980 / 1550 wavelength division multiplexer 103... The second output terminal of 3 is connected to the input terminal of the 1550nm isolator 105. The output terminal of the 1550nm isolator 105 is connected to the input terminals of the delay fiber 107 and the acousto-optic modulator 108 (AOM) respectively through a 1×2 coupler 106. The output terminals of the delay fiber 107 and the acousto-optic modulator 108 are both connected to the input terminal of the balanced photodetector 110 through a 2×2 coupler 109. The output terminal of the balanced photodetector 110 is connected to the output terminal of the fiber heterodyne interferometric ultrasonic sensing module 10.

[0041] Understandably, the pump laser 101 can excite the FBG-FL to generate a 1550nm wavelength laser. When external ultrasound acts on the FBG-FL, it will cause periodic changes in its refractive index and grating length, affecting the center wavelength of the FBG-FL output laser. Thus, by demodulating the wavelength of the FBG-FL output laser, ultrasonic sensing can be achieved.

[0042] Using a transformer partial discharge detection device, and following the installation requirements of devices such as FBG-FL in the fiber optic heterodyne interferometric ultrasonic sensing module 10, the fiber optic heterodyne interferometric ultrasonic sensing module 10 is installed. For example, the FBG-FL is tightly wound around the transformer housing. The operating principle of the fiber optic heterodyne interferometric ultrasonic sensing module 10 is as follows: the output of the pump laser 101 is connected to a 980nm optical isolator 102. The output light from the 980nm optical isolator 102 enters a 980 / 1550nm wavelength division multiplexer 103. The 980 / 1550nm wavelength division multiplexer 103 is connected to four FBG-FLs, exciting them to generate a 1550nm wavelength laser. The laser signal will carry and act on the FBG-FLs. The ultrasonic signal and the laser signal are sequentially split into two laser signals by a 1550nm isolator 105 and a 1×2 coupler 106. One laser signal is input into a delay fiber 107, and the other is connected to an acousto-optic modulator 108 to generate a frequency shift, converting the wavelength change of the laser into a phase change. The two laser signals interfere at the 2×2 coupler 109 to obtain an interference light signal, which constitutes an unbalanced Mach-Zehnder interferometer. The interference light signal is photoelectrically converted by a balanced photodetector 110 to obtain the signal to be measured, namely the partial discharge ultrasonic signal. Subsequently, the partial discharge ultrasonic signal is phase demodulated by the hardware phase demodulation module 20 to obtain the ultrasonic signal acting on the FBG-FL, namely the demodulated signal.

[0043] This embodiment designs a fiber optic heterodyne interferometric ultrasonic sensing module 10, which can be used to acquire partial discharge ultrasonic signals.

[0044] In a preferred embodiment, the hardware phase demodulation module 20 includes a first RF phase detector 201, a second RF phase detector 202, a 1:1 power divider 203, a 90° phase shifter, a first bandpass filter 204, and a second bandpass filter 205. The first input terminals of both the first RF phase detector 201 and the second RF phase detector 202 are connected to the input terminals of the hardware phase demodulation module 20. The input terminal of the 1:1 power divider 203 is connected to the output terminal of the driver that drives the acousto-optic modulator 108. The output terminal of the 1:1 power divider 203 is connected to the second input terminal of the first RF phase detector 201. The output terminal of the 1:1 power divider 203 is connected to the second input terminal of the second RF phase detector 202 through a 90° phase shifter. The output terminal of the first RF phase detector 201 is connected to the input terminal of the first bandpass filter 204. The output terminal of the second RF phase detector 202 is connected to the input terminal of the second bandpass filter 205. The output terminals of the first bandpass filter 204 and the second bandpass filter 205 are both connected to the output terminal of the hardware phase demodulation module 20.

[0045] As an example, a hardware phase demodulation module 20 is designed, and a schematic diagram of the hardware phase demodulation module 20 is shown below. Figure 2 As shown. In Figure 2 In this configuration, the first input terminals of the first RF phase detector 201 and the second RF phase detector 202 are both connected to the input terminal of the hardware phase demodulation module 20. The input terminal of the 1:1 power divider 203 is connected to the output terminal of the driver (not shown) driving the acousto-optic modulator 108. The output terminal of the 1:1 power divider 203 is connected to the second input terminal of the first RF phase detector 201. The output terminal of the 1:1 power divider 203 is connected to the second input terminal of the second RF phase detector 202 through a 90° phase shifter (not shown). The output terminal of the first RF phase detector 201 is connected to the input terminal of the first bandpass filter 204. The output terminal of the second RF phase detector 202 is connected to the input terminal of the second bandpass filter 205. The output terminals of the first bandpass filter 204 and the second bandpass filter 205 are both connected to the output terminal of the hardware phase demodulation module 20.

[0046] The transformer partial discharge detection device operates with a hardware phase demodulation module 20. The specific operating principle of the hardware phase demodulation module 20 is as follows: Two DC-to-2GHz radio frequency phase detectors, namely the first radio frequency phase detector 201 and the second radio frequency phase detector 202, are used to demodulate the phase of the partial discharge ultrasonic signal. The partial discharge ultrasonic signal output from the fiber optic heterodyne interferometric ultrasonic sensing module 10 is split into two ultrasonic signals. One signal is input to the first radio frequency phase detector 201, and the other is input to the second radio frequency phase detector 202. A 1:1 power divider 203 obtains a reference signal from the driver of the acousto-optic modulator 108 and splits it into two reference signals. One signal is directly input to the first radio frequency phase detector 201, and the other signal is shifted by 90° by a 90° phase shifter before being input to the second radio frequency phase detector 202. At this time, the first radio frequency phase detector 201... The outputs of the second RF phase detector 202 are the phase difference signals of the ultrasonic signal and their respective reference signals, respectively, so that the nonlinear regions of the two output signals are staggered. That is, when one of the first RF phase detectors 201 and the second RF phase detector 202 is in a nonlinear operating state, the other RF phase detector will be in a linear operating state. A first bandpass filter 204 with a frequency band of 20kHz to 200kHz is connected in series at the output terminal of the first RF phase detector 201, and a second bandpass filter 205 with a frequency band of 20kHz to 200kHz is connected in series at the output terminal of the second RF phase detector 202. The first bandpass filter 204 and the second bandpass filter 205 can filter out the low-frequency carrier in the corresponding output signal and retain the small high-frequency phase voltage signal, thus completing hardware demodulation. The minimum phase resolution is 4mrad.

[0047] This embodiment designs a hardware phase demodulation module 20, which can use hardware demodulation to demodulate the partial discharge ultrasonic signal collected by the fiber optic heterodyne interferometric ultrasonic sensing module 10, reducing the demodulation time from minutes to seconds, thus effectively shortening the demodulation time.

[0048] In a preferred embodiment, the multi-channel synchronous data acquisition module 30 includes a plurality of digital-to-analog converters 301, an FPGA controller 302, and a first memory 303; the input terminal of each digital-to-analog converter 301 is connected to the input terminal of the multi-channel synchronous data acquisition module 30, the output terminal of each digital-to-analog converter 301 is connected to the input terminal of the FPGA controller 302, the output terminal of the FPGA controller 302 is connected to the input terminal of the first memory 303, and the output terminal of the FPGA controller 302 is connected to the output terminal of the multi-channel synchronous data acquisition module 30.

[0049] As an example, the number of digital-to-analog converters 301 is determined based on the number of sensor signal acquisition channels in the actual application, and the FPGA controller 302 and the first memory 303 are selected accordingly. For example, assuming that the fiber optic heterodyne interferometric ultrasonic sensing module 10 acquires four partial discharge ultrasonic signals, and several partial discharge sensors are selected, including three ultra-high frequency sensors and a high frequency current sensor, acquiring a total of six partial discharge sensing signals, then ten digital-to-analog converters 301 are configured. The selected FPGA controller 302 is used to process the output signals of each digital-to-analog converter 301 in parallel. The FPGA controller 302 includes 6M logic units and an 8Gb / s data transceiver. For the different sampling rate requirements of each digital-to-analog converter 301, the first memory 303 can be a high-speed streaming memory, which has an 8G high frequency (4300MHz main frequency) and a 4G low frequency (3200MHz main frequency). A multi-channel synchronous data acquisition module 30 is designed, and its structural schematic diagram is shown below. Figure 3 As shown. In Figure 3 In this configuration, the input terminal of each digital-to-analog converter 301 is connected to the input terminal of the multi-channel synchronous data acquisition module 30, the output terminal of each digital-to-analog converter 301 is connected to the input terminal of the FPGA controller 302, the output terminal of the FPGA controller 302 is connected to the input terminal of the first memory 303, and the output terminal of the FPGA controller 302 is connected to the output terminal of the multi-channel synchronous data acquisition module 30.

[0050] The transformer partial discharge detection device is used to run the multi-channel synchronous data acquisition module 30. The operating principle of the multi-channel synchronous data acquisition module 30 is as follows: each digital-to-analog converter 301 performs analog-to-digital conversion on the corresponding sensing signal, i.e., the demodulated signal or the partial discharge sensing signal. The FPGA controller 302 controls the demodulated signal and all partial discharge sensing signals to be written into the memory according to the sampling clock of all digital-to-analog converters 301.

[0051] This embodiment designs a multi-channel synchronous data acquisition module 30, which can coordinate the real-time transmission of multiple sensor signals.

[0052] In a preferred embodiment, the connection interface between the FPGA controller 302 and all digital-to-analog converters 301 is a CMOS-LVDS mixed data interface.

[0053] As an example, in order to achieve high-speed data transmission and reduce transmission power consumption of the digital-to-analog converter 301, the connection interface between the FPGA controller 302 and all digital-to-analog converters 301 is a CMOS-LVDS hybrid data interface. At this time, the FPGA controller 302 can make a judgment based on the sampling rate and acquisition time set by the host computer. When the conversion rate is lower than 220Msps, it switches to the CMOS communication interface, and when the conversion rate is higher than 220Msps, it uses the LVDS data interface.

[0054] This embodiment uses a CMOS-LVDS hybrid data interface as the connection interface between the FPGA controller 302 and the digital-to-analog converter 301, which enables high-speed data transmission of the digital-to-analog converter 301 and reduces transmission power consumption.

[0055] In a preferred embodiment, the sensor signal uploading module includes a processor and a second memory; the input terminal of the processor is connected to the input terminal of the sensor signal uploading module 40, the output terminal of the processor is connected to the input terminal of the second memory, and the output terminal of the processor is connected to the output terminal of the sensor signal uploading module 40.

[0056] As an example, an embedded processor is selected as the processor, and a high-speed memory with a size of 120G and a transfer rate of 4000MB / s is selected as the second memory. A sensor signal uploading module 40 is designed.

[0057] Understandably, by configuring a processor in the sensor signal uploading module 40, it is possible to combine actual application needs, such as when the host computer's data processing pressure is too high and the processor needs to share the processing of multiple sensor signals, the processor can first process the demodulated signal and several partial discharge sensor signals, and then upload the demodulated signal and several partial discharge sensor signals.

[0058] Specifically, the demodulated signal processing involves processing the output signals A and B of the first RF phase detector 201 and the second RF phase detector 202 in the hardware phase demodulation module 20. By using envelope and peak finding, the nonlinear region position and width of the output signal of the first RF phase detector 201 are output. Then, the linear output of the second RF phase detector 202 at that point is compensated to the signal, and a spliced ​​signal composed of the linear regions of output signals A and B is output, thereby obtaining a stable signal and effectively avoiding the nonlinear region. After reconstructing the stable signal, a fast Fourier transform is performed on the stable signal to obtain the phase modulation amplitude in the stable signal.

[0059] This embodiment, by designing a sensor signal uploading module 40, can not only coordinate the real-time transmission of multiple sensor signals, but also assist the host computer in processing multiple sensor signals, which is beneficial to improving the detection efficiency of partial discharge in transformers.

[0060] In a preferred embodiment, the connection interface between the sensor signal uploading module 40 and the host computer is a high-speed serial bus interface.

[0061] As an example, the connection interface between the sensor signal uploading module 40 and the host computer is a high-speed serial bus interface, such as a PCIe bus interface.

[0062] In practical applications, the hardware phase demodulation module 20, the multi-channel synchronous data acquisition module 30, and the sensor signal upload module 40 can be integrated on the same PCB board and transmitted to the host computer via the PCIe bus interface.

[0063] In this embodiment, a high-speed serial bus interface is selected as the connection interface between the sensor signal upload module 40 and the host computer, which is beneficial to improving the data transmission rate.

[0064] In a preferred embodiment, the partial discharge sensor is an ultra-high frequency sensor, a high frequency current sensor, or an ultrasonic sensor.

[0065] As an example, the partial discharge sensor may be an ultra-high frequency sensor, a high frequency current sensor, or an ultrasonic sensor.

[0066] By using a transformer partial discharge detection device, each partial discharge sensor is installed according to the installation requirements of the selected partial discharge sensors. For example, the ultra-high frequency sensor is placed outside the transformer tank, and the high frequency current sensor is installed at the neutral line of the transformer. This allows the partial discharge sensors to collect several partial discharge sensing signals.

[0067] This embodiment uses ultra-high frequency sensors, high frequency current sensors, or ultrasonic sensors as partial discharge sensors, which can provide diverse multi-channel sensing signals and improve the detection efficiency of transformer partial discharge.

[0068] The second embodiment provides a transformer partial discharge detection system, including a transformer partial discharge detection device as described in the first embodiment and a host computer; the transformer partial discharge detection device is communicatively connected to the host computer; the host computer includes: a mode selection module, used to determine several partial discharge sensors according to the partial discharge detection mode selected by the user; a parameter configuration module, used to configure the parameters of each partial discharge sensor, so that the transformer partial discharge detection device can upload the demodulated signal and several partial discharge sensor signals in real time; and a signal processing module, used to process the demodulated signal to obtain a stable signal, and perform a fast Fourier transform on the stable signal to obtain the phase modulation amplitude of the stable signal.

[0069] As an example, in the application of a transformer partial discharge detection system, a host computer is run. Using a mode selection module, based on the user-selected partial discharge detection mode (e.g., at least one of ultra-high frequency method, high-frequency current method, and ultrasonic method), several partial discharge sensors are determined. Using a parameter configuration module, the parameters of each partial discharge sensor are configured to start the transformer partial discharge detection device. This allows the device to upload demodulated signals and signals from several partial discharge sensors in real time. Using a signal processing module, the demodulated signal is processed to obtain a stable signal, and a fast Fourier transform is performed on the stable signal to obtain... To obtain the phase modulation amplitude of the stable signal, the following steps are taken: The output signals A and B of the first RF phase detector 201 and the second RF phase detector 202 in the hardware phase demodulation module are processed. The nonlinear region position and width of the output signal of the first RF phase detector 201 are obtained by envelope and peak finding. Then, the linear output of the second RF phase detector 202 at that point is compensated to the signal, and a spliced ​​signal composed of the linear regions of the output signals A and B is output, thereby obtaining the stable signal and effectively avoiding the nonlinear region. After reconstructing the stable signal, a fast Fourier transform is performed on the stable signal to obtain the phase modulation amplitude in the stable signal.

[0070] In practical applications, LabVIEW software can be configured on the host computer to create a human-computer interface, providing users with options for partial discharge detection modes, parameter configuration methods, and input methods. The host computer can display and save the original waveforms and data of multiple sensor signals in real time according to actual detection needs, monitor the data acquisition status, and perform time-domain, frequency-domain, amplitude, and phase distribution analysis on the original waveforms of the acquired multiple sensor signals, displaying the relevant results. This provides a basis for partial discharge diagnosis and helps improve the detection efficiency of transformer partial discharge.

[0071] This embodiment designs a transformer partial discharge detection system that can acquire multiple sensor signals in real time for partial discharge detection, which helps to improve the detection efficiency of transformer partial discharge.

[0072] In a preferred embodiment, the parameter configuration module is specifically used to retrieve the parameters of each partial discharge sensor from the sensor feature parameter database, and configure the parameters of each partial discharge sensor according to the parameters of each partial discharge sensor.

[0073] In a preferred embodiment, the parameter configuration module is further configured to configure the parameters of the partial discharge sensor according to the user's custom parameters input for the partial discharge sensor.

[0074] As an example, after determining the types of several partial discharge sensors selected by the user, the host computer can directly retrieve the parameters of each partial discharge sensor from the sensor characteristic parameter database, configure the parameters of each partial discharge sensor according to the parameters of each partial discharge sensor in the preset database, or wait to obtain the parameters of each partial discharge sensor uploaded by the user, and configure the parameters of each partial discharge sensor according to the parameters of each partial discharge sensor customized by the user.

[0075] This embodiment stores parameters of different partial discharge sensors by pre-configuring a sensor characteristic parameter database. After connecting the partial discharge sensor, the acquisition parameters that match the type of partial discharge sensor can be directly selected. It is compatible with partial discharge sensors of different manufacturers and signals, and has strong adaptability. By providing a channel for user-defined parameters, it can effectively meet actual detection needs and has strong flexibility.

[0076] In summary, implementing the embodiments of the present invention has the following beneficial effects:

[0077] By designing a transformer partial discharge detection device, an optical fiber heterodyne interferometric ultrasonic sensing module is used to collect ultrasonic signals when partial discharge occurs in the transformer, obtaining the partial discharge ultrasonic signal. A hardware phase demodulation module is used to demodulate the phase of the partial discharge ultrasonic signal, obtaining a demodulated signal. A multi-channel synchronous data acquisition module is used to acquire the demodulated signal and the partial discharge sensing signals collected by several partial discharge sensors. A sensor signal uploading module is used to upload the demodulated signal and all partial discharge sensing signals to the host computer in real time. This enables the real-time acquisition of multiple sensor signals for partial discharge detection, which is beneficial to improving the detection efficiency of transformer partial discharge.

[0078] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

[0079] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above embodiments. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

Claims

1. A transformer partial discharge detection device, characterized in that, Includes a fiber optic heterodyne interferometric ultrasonic sensing module, a hardware phase demodulation module, a multi-channel synchronous data acquisition module, and a sensor signal uploading module. The output of the fiber optic heterodyne interferometric ultrasonic sensing module is connected to the input of the hardware phase demodulation module. The output of the hardware phase demodulation module is connected to the input of the multi-channel synchronous data acquisition module. The output of the multi-channel synchronous data acquisition module is connected to the input of the sensing signal uploading module. The output of the sensing signal uploading module is connected to the host computer. The fiber optic heterodyne interferometric ultrasonic sensing module is used to acquire ultrasonic signals when partial discharge occurs in a transformer, thereby obtaining partial discharge ultrasonic signals. The module includes a pump laser, an optical isolator, a wavelength division multiplexer (WDM), several FBG fiber lasers, an isolator, a 1×2 coupler, a delay fiber, an acousto-optic modulator, a 2×2 coupler, and a balanced photodetector. Specifically, there are four FBG fiber lasers, the optical isolator is 980 nm, the WDM is 980 / 1550 nm, and the isolator is 1550 nm. The pump laser excites the FBG-FL to generate a 1550 nm wavelength laser. When external ultrasonic waves act on the FBG-FL, they trigger periodic changes in the refractive index and grating length of the FBG-FL, affecting the center wavelength of the output laser. This demodulates the center wavelength of the output laser, achieving ultrasonic sensing. The hardware phase demodulation module is used to demodulate the partial discharge ultrasonic signal to obtain a demodulated signal. The hardware phase demodulation module includes a first radio frequency (RF) phase detector, a second RF phase detector, a 1:1 power divider, a 90° phase shifter, a first bandpass filter, and a second bandpass filter. The first input terminals of the first and second RF phase detectors are both connected to the input terminal of the hardware phase demodulation module. The input terminal of the 1:1 power divider is connected to the output terminal of the driver that drives the acousto-optic modulator. The output terminal of the 1:1 power divider is connected to the second input terminal of the first RF phase detector. The output terminal of the 1:1 power divider is connected to the second input terminal of the second RF phase detector via the 90° phase shifter. The output terminal of the first RF phase detector is connected to the input terminal of the first bandpass filter. The output terminal of the second RF phase detector is connected to the input terminal of the second bandpass filter. The output terminals of both the first and second bandpass filters are connected to the output terminal of the hardware phase demodulation module. The multi-channel synchronous data acquisition module is used to acquire the demodulated signal and the partial discharge sensing signals collected by several partial discharge sensors. The sensor signal uploading module is used to upload the demodulated signal and all the partial discharge sensor signals to the host computer in real time.

2. The transformer partial discharge detection device as described in claim 1, characterized in that, The output of the pump laser is connected to the input of the optical isolator. The output of the optical isolator is connected to the first input of the wavelength division multiplexer. The first output of the wavelength division multiplexer is connected to the input of each FBG fiber laser. The output of each FBG fiber laser is connected to the second input of the wavelength division multiplexer. The second output of the wavelength division multiplexer is connected to the input of the isolator. The output of the isolator is connected to the input of the delay fiber and the acousto-optic modulator via the 1×2 coupler. The outputs of the delay fiber and the acousto-optic modulator are both connected to the input of the balanced photodetector via the 2×2 coupler. The output of the balanced photodetector is connected to the output of the heterodyne interferometric ultrasonic sensing module.

3. The transformer partial discharge detection device as described in claim 1, characterized in that, The multi-channel synchronous data acquisition module includes several digital-to-analog converters, an FPGA controller, and a first memory; The input terminal of each of the digital-to-analog converters is connected to the input terminal of the multi-channel synchronous data acquisition module, the output terminal of each of the digital-to-analog converters is connected to the input terminal of the FPGA controller, the output terminal of the FPGA controller is connected to the input terminal of the first memory, and the output terminal of the FPGA controller is connected to the output terminal of the multi-channel synchronous data acquisition module.

4. The transformer partial discharge detection device as described in claim 3, characterized in that, The FPGA controller and all the digital-to-analog converters are connected via a CMOS-LVDS hybrid data interface.

5. The transformer partial discharge detection device as described in claim 1, characterized in that, The sensor signal uploading module includes a processor and a second memory; The processor's input terminal is connected to the input terminal of the sensor signal uploading module, the processor's output terminal is connected to the input terminal of the second memory, and the processor's output terminal is connected to the output terminal of the sensor signal uploading module.

6. The transformer partial discharge detection device as described in claim 1, characterized in that, The connection interface between the sensor signal uploading module and the host computer is a high-speed serial bus interface.

7. The transformer partial discharge detection device as described in claim 1, characterized in that, The partial discharge sensor is an ultra-high frequency sensor, a high frequency current sensor, or an ultrasonic sensor.

8. A transformer partial discharge detection system, characterized in that, Includes the transformer partial discharge detection device as described in any one of claims 1 to 7; The transformer partial discharge detection device is communicatively connected to the host computer. The host computer includes: The mode selection module is used to determine several partial discharge sensors based on the partial discharge detection mode selected by the user. The parameter configuration module is used to configure the parameters of each of the partial discharge sensors, so that the transformer partial discharge detection device can upload the demodulated signal and several partial discharge sensor signals in real time. The signal processing module is used to process the demodulated signal to obtain a stationary signal, and to perform a fast Fourier transform on the stationary signal to obtain the phase modulation amplitude of the stationary signal.

9. The transformer partial discharge detection system as described in claim 8, characterized in that, The parameter configuration module is specifically used to retrieve the parameters of each partial discharge sensor from the sensor feature parameter database, and configure the parameters of each partial discharge sensor according to the parameters of each partial discharge sensor.

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