A method for detecting overall performance of a power transformer monitoring device

Abstract

The application provides a kind of overall performance detection method of power transformer monitoring device, comprising: the anti-interference performance of the transformer monitoring device to be measured is detected;The discharge development trend early warning function of the transformer monitoring device to be measured is detected;The multi-parameter synchronous acquisition, real-time display function of the transformer monitoring device to be measured is detected;The discharge type identification function of the transformer monitoring device to be measured is detected;The discharge source fault positioning function of the transformer monitoring device to be measured is detected;The ground potential lifting tolerance function of the transformer monitoring device to be measured is detected;The UHF sensor sealing function of the transformer monitoring device to be measured is detected.The application can evaluate the overall function of transformer monitoring device, improve the effectiveness of transformer online monitoring.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power systems, in particular to a kind of overall performance detection method of power transformer monitoring device. BACKGROUND

[0002] Power transformer (reactor) is the core equipment in power grid, and monitoring its operating state is crucial for the safety and stability of power grid. Partial discharge online monitoring is an important technical means for transformer (reactor) state evaluation, fault diagnosis and early warning. With the rapid development of monitoring technology, partial discharge comprehensive monitoring device is rapidly popularized in oil-filled equipment.

[0003] However, the partial discharge comprehensive monitoring device in the prior art focuses on the detection of single parameter indicators, and it is difficult to evaluate the device's resistance to external interference, discharge type identification, fault positioning and other performances, and it is impossible to judge the overall function of the transformer (reactor) partial discharge comprehensive monitoring device. SUMMARY

[0004] Therefore, the present application proposes an overall performance detection method of power transformer monitoring device, aiming to solve the problem that the overall performance of the existing power transformer monitoring device is difficult to be comprehensively detected.

[0005] In one aspect, the present application proposes an overall performance detection method of power transformer monitoring device, comprising the following steps:

[0006] Step 1, detecting the anti-interference performance of the transformer monitoring device to be tested;

[0007] Step 2, detecting the discharge development trend early warning function of the transformer monitoring device to be tested;

[0008] Step 3, detecting the multi-parameter synchronous acquisition and real-time display function of the transformer monitoring device to be tested;

[0009] Step 4, detecting the discharge type identification function of the transformer monitoring device to be tested;

[0010] Step 5, detecting the discharge source fault positioning function of the transformer monitoring device to be tested;

[0011] Step 6, detecting the ground potential lifting tolerance function of the transformer monitoring device to be tested;

[0012] Step 7, detecting the ultrahigh frequency sensor sealing function of the transformer monitoring device to be tested.

[0013] Further, the overall performance detection method of the power transformer monitoring device described above, the step 1 comprises:

[0014] The high-frequency pulse current with the apparent charge Q is generated in the test circuit by using the steep pulse generator and the injection capacitor, and the interference current with different frequencies is generated by using the sine signal generator Us through the resistor R, and is applied to the input end of the high-frequency sensor connected to the transformer monitoring device to be tested, so that the high-frequency partial discharge anti-interference performance detection of the transformer monitoring device to be tested is performed.

[0015] The ultrasonic wave partial discharge anti-interference performance detection of the transformer monitoring device to be tested is performed by using the acoustic emission system or the signal generator to output a group of pulse signals.

[0016] The ultra-high frequency partial discharge anti-interference performance detection of the transformer monitoring device to be tested is performed by using the detector, the ultra-high frequency sensor and the steep pulse source generator to build a test circuit.

[0017] The anti-corona interference performance detection of the transformer monitoring device to be tested is performed by using the ultrasonic sensor, the high-frequency sensor and the ultra-high frequency sensor to build a test circuit.

[0018] Further, in the overall performance detection method of the power transformer monitoring device, the step 2 comprises:

[0019] The ultrasonic sensor, the high-frequency sensor and the ultra-high frequency sensor are installed on the transformer body and connected to the transformer monitoring device to be tested, the transformer monitoring device to be tested is powered on and operated, the surface discharge fault type is selected, the surface discharge is in three stages, the initial stage, the development stage and the breakdown stage by applying different voltages to the transformer body, and the monitoring values in different stages are recorded by the transformer monitoring device to be tested and pre-alarm and alarm.

[0020] Further, in the overall performance detection method of the power transformer monitoring device, the step 3 comprises:

[0021] The ultrasonic sensor, the high-frequency sensor and the ultra-high frequency sensor are installed on the transformer body and connected to the transformer monitoring device to be tested, the floating discharge is simulated, and the acoustic wave data, the high-frequency data and the ultra-high frequency data are collected by the transformer monitoring device to be tested.

[0022] Further, in the overall performance detection method of the power transformer monitoring device, the step 4 comprises:

[0023] The high-frequency sensor and the ultra-high frequency sensor are installed on the transformer body and connected to the transformer monitoring device to be tested, the floating discharge, the surface discharge, the insulation paper discharge and the impurity discharge are simulated, and the fault recognition accuracy of the transformer monitoring device to be tested is determined.

[0024] Further, in the overall performance detection method of the power transformer monitoring device, the step 5 comprises:

[0025] The ultrasonic sensor, the high-frequency sensor and the ultra-high frequency sensor are installed on the transformer body and connected with the transformer monitoring device to be measured; a suspension fault type is selected, a preset voltage is applied to the transformer body, a fault model discharge is performed, a three-dimensional coordinate of a fault point positioned by the transformer monitoring device to be measured is recorded, a position of a three-time suspension discharge fault source is changed, and a fault positioning coordinate of the comprehensive monitoring device is recorded.

[0026] Further, in the overall performance detection method of the power transformer monitoring device, the step 6 comprises:

[0027] The ultrasonic sensor, the high-frequency sensor and the ultra-high frequency sensor are installed on the transformer body and connected with the transformer monitoring device to be measured;

[0028] The transformer monitoring device is placed on a single-point grounded metal plate insulated from the ground and is operated with power on;

[0029] The output voltage waveform and amplitude of the steep shock wave generator are adjusted, and the steep shock voltage is applied to the outer wall of the box body of the transformer body for multiple times.

[0030] Further, in the overall performance detection method of the power transformer monitoring device, the step 7 comprises:

[0031] The ultra-high frequency sensor is installed on the reserved flange interface of the transformer body and connected with the transformer monitoring device to be measured;

[0032] The transformer body is vacuumized to a pressure lower than 0.3 kPa;

[0033] The valve connected with the vacuum pump is closed, the vacuum value P1 is read after a first preset time length, and the vacuum value P2 is read after a second preset time length;

[0034] Whether the sealing property is qualified is judged according to a difference between the two pressure values.

[0035] Further, in the overall performance detection method of the power transformer monitoring device, the step 8 comprises:

[0036] The high-frequency signal time-frequency separation classification function of the transformer monitoring device to be measured is detected.

[0037] Further, in the overall performance detection method of the power transformer monitoring device, the step 8 comprises:

[0038] The high-frequency sensor is installed on the transformer body, one end of the high-frequency interference excitation source is placed on the top of the core and the clamping member of the transformer body, the other end is placed on the bottom of the core and the clamping member, the floating fault type is selected, a preset voltage is applied to the transformer body, the discharge monitoring spectrum of the high-frequency monitoring unit is recorded, the system voltage is zeroed, the interference signal simulation device simulates the on-site interference signal of the ground noise, the power amplifier is adjusted so that the amplitude of the interference signal is equal to the amplitude of the partial discharge under the voltage of 50kV, the noise monitoring spectrum is recorded, and the transformer body is applied with the voltage of 50kV again, the high-frequency monitoring unit of the transformer monitoring device to be detected receives the partial discharge signal and the on-site interference signal at the same time, the data separation function of the device is started, and the device can display the two monitoring spectrum data of the ground noise and the discharge.

[0039] The application can detect the following functions of the transformer monitoring device: multi-parameter synchronous acquisition, multi-parameter synchronous real-time display function; high-frequency, ultra-high frequency partial discharge phase distribution map (PRPD), pulse sequence phase distribution map (PRPS) function detection; high-frequency pulse waveform polarity contrast analysis function detection; high-frequency signal time-frequency separation classification function detection; high-frequency, ultrasonic wave, ultra-high frequency and other monitoring anti-external interference ability function detection; discharge type identification function detection; discharge source fault positioning accuracy function detection; fault early warning, alarm and data playback function detection, through the above function detection, the overall function of the transformer monitoring device can be evaluated, and the effectiveness of the online monitoring of the transformer is improved. BRIEF DESCRIPTION OF DRAWINGS

[0040] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are for purposes of illustration only and are not intended to limit the application thereto. The same reference numbers in different drawings identify the same components. In the drawings:

[0041] Figure 1 The flow chart of the overall performance detection method of the power transformer monitoring device provided by the embodiment of the application;

[0042] Figure 2 The high-frequency partial discharge anti-interference performance test wiring diagram in the overall performance detection method of the power transformer monitoring device provided by the embodiment of the application;

[0043] Figure 3 The ultrasonic wave partial discharge anti-interference performance test wiring diagram in the overall performance detection method of the power transformer monitoring device provided by the embodiment of the application;

[0044] Figure 4 The ultra-high frequency partial discharge anti-interference performance test wiring diagram in the overall performance detection method of the power transformer monitoring device provided by the embodiment of the application;

[0045] Figure 5 The system diagram for carrying out the corona anti-interference test in the overall performance detection method of the power transformer monitoring device provided by the embodiment of the present application;

[0046] Figure 6 The ground potential lifting test wiring diagram in the overall performance detection method of the power transformer monitoring device provided by the embodiment of the present application. DETAILED DESCRIPTION

[0047] Exemplary embodiments of the present disclosure will be described in detail with reference to the drawings. Although exemplary embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly understood, and the scope of the present disclosure can be accurately conveyed to those skilled in the art. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in conjunction with the embodiments.

[0048] With reference to Figure 1 The overall performance detection method of the power transformer monitoring device of the embodiment of the present application includes the following steps:

[0049] Step S1, detecting the anti-interference performance of the transformer monitoring device to be tested.

[0050] Specifically, this step includes the following sub-steps:

[0051] Sub-step S11, using a steep pulse generator and an injection capacitor to generate a high-frequency pulse current with an apparent charge amount of Q in the test loop, and using a sine signal generator Us to generate an interference current with different frequencies through a resistor R, and simultaneously applying to the input end of the high-frequency sensor connected to the transformer monitoring device to be tested, to detect the high-frequency partial discharge anti-interference performance of the transformer monitoring device to be tested.

[0052] In combination Figure 2, in particular implementation, through the steep pulse generator Up and injection capacitor C0 in the test circuit to produce apparent charge amount of Q high-frequency pulse current, while using a sine signal generator Us through the resistance R (50 Ω) to produce different frequency of interference current, while applied to the input end of high-frequency sensor (HFCT). In the case of any given frequency of interference current, allow adjustment of the filter function of the transformer monitoring device to be measured. When the measured apparent charge amount Q is 50 pC, the peak-peak value of the interference current IS is 25 mA, the transformer monitoring device to be measured can display the measured pulse signal with a signal-to-noise ratio of not less than 2:1. The frequency of the interference current is preferably selected from 50 kHz, 500 kHz, 1 MHz, 2 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz, 25 MHz, 30 MHz, 35 MHz, 40 MHz.

[0053] According to the following criterion "adjust the detection frequency in the frequency band of 3 MHz~30MHz, the interference signal suppression ability is not less than 20dB", judge whether the high-frequency partial discharge anti-interference performance of the transformer monitoring device to be measured is qualified.

[0054] Sub-step S12, a set of pulse signals are output by the acoustic emission system or signal generator to detect the ultrasonic partial discharge anti-interference performance of the transformer monitoring device to be measured.

[0055] Referring to Figure 3 , in particular implementation, a set of pulse signals (measured signals) with pulse width not less than 1 μs and amplitude not less than 1 V are output by the acoustic emission system or signal generator, and a certain frequency of sine wave signal (interference signal) is generated by the interference simulation device. Adjust the amplitude of the interference signal so that the amplitude of the interference signal is equal to the amplitude of the measured pulse signal. The device enables the anti-interference function, and the measured device can display the measured pulse signal with a signal-to-noise ratio of not less than 2:1. The frequency of the interference signal is 50 kHz, 100 kHz, 150 kHz, 200 kHz, 250 kHz, 300 kHz.

[0056] According to the following criterion "in the presence of interference test environment, the measured device can display the measured pulse signal with a signal-to-noise ratio of not less than 2:1", judge whether the ultrasonic partial discharge anti-interference performance of the transformer monitoring device to be measured is qualified.

[0057] Sub-step S13, a test circuit is built by using the detector, the ultra-high frequency sensor and the steep pulse source generator to detect the ultra-high frequency partial discharge anti-interference performance of the transformer monitoring device to be measured.

[0058] Referring to Figure 4 , in particular implementation, the performance test is carried out according to the following steps:

[0059] Step (a), build a transformer ultra-high frequency monitoring system anti-interference ability test loop, PC responsible for control pulse source to send specified pulse and communication with detection instrument, get the measurement results of detection instrument. Steep pulse source is responsible for sending specified waveform and specified timing pulse signal, to simulate typical discharge and typical interference. Detection instrument is the checked ultra-high frequency detection system, GTEM small room is responsible for providing stable, traceable electric field test environment. Ultra-high frequency sensor is placed at the window of GTEM small room.

[0060] Step (b), noise sensor adopts omnidirectional cone spiral antenna, responsible for sending noise signal, simulating environmental noise; PC controls pulse signal source CH1 to send discharge simulation signal, signal injection GTEM small room, pulse signal source CH2 sends interference simulation signal, signal injection noise sensor, and radiate to the space around.

[0061] Step (c), open the measured instrument system, and test for a certain specified time (such as 10 seconds) to get the spectrum data (PRPD or PRPS spectrum) or pulse waveform interface in this test time;

[0062] Step (d), signal simulation channel is always open, and the comparison of noise simulation channel opening and closing state is carried out, and the spectrum data (PRPD or PRPS spectrum) or pulse waveform interface of the tested instrument can display the measured pulse signal with a signal-to-noise ratio not less than 2:1;

[0063] Step (e), repeat steps b) ~ d) for multiple times (10 times and above).

[0064] According to the following criterion "monitoring system should have the suppression ability to typical narrowband interference, and the measured device can display the measured pulse signal with a signal-to-noise ratio not less than 2:1 in the test environment with narrowband interference", whether the ultra-high frequency partial discharge anti-interference performance of the measured transformer monitoring device is qualified is judged.

[0065] Substep S14, use ultrasonic sensor, high frequency sensor and ultra-high frequency sensor to build test loop to detect the anti-corona interference performance of the measured transformer monitoring device (as shown in Figure 5 ).

[0066] In specific implementation, the test is carried out according to the following steps:

[0067] Step (a), adjust the suspended fault model, apply a certain voltage, generate suspended discharge in the transformer, open the comprehensive monitoring system, ensure that the system can receive the ultra-high frequency signal, ultrasonic signal and high frequency signal generated by the suspended discharge, and test for a certain specified time (such as 20 seconds) to get the spectrum data (PRPD or PRPS spectrum) or pulse waveform interface in this test time.

[0068] Step (b), voltage zero, cut off power, put the tip discharge model on the top of the high voltage sleeve, the function detection system applies a certain voltage, so that it produces both floating discharge and corona discharge. The external corona discharge spreads to the space, and the internal floating discharge spreads in the transformer. The pulse current method is used to monitor the apparent discharge discharge value, so that the amplitude of the corona discharge and the amplitude of the floating discharge are close to a 1:1 relationship.

[0069] Step (c), open the comprehensive monitoring device interference suppression function, and the high frequency, very high frequency, ultrasonic spectrum data or pulse waveform interface of the device under test can display the discharge signal generated by the floating discharge with a signal-to-noise ratio of not less than 2:1.

[0070] Step (d), repeat steps a) to c) multiple times (10 times or more).

[0071] According to the criterion "in the test environment where external corona interference exists, the device under test can display the pulse signal with a signal-to-noise ratio of not less than 2:1", it is judged whether the external corona interference suppression ability of the transformer monitoring device under test is qualified.

[0072] Step S2, the discharge development trend warning function of the transformer monitoring device under test is detected.

[0073] In specific implementation, the ultrasonic sensor, high frequency sensor and very high frequency sensor are installed on the transformer body and connected with the transformer monitoring device under test, the floating discharge is simulated, and the sound wave data, high frequency data and very high frequency data are collected by the transformer monitoring device under test.

[0074] Step S3, the multi-parameter synchronous acquisition and real-time display function of the transformer monitoring device under test is detected.

[0075] In specific implementation, the high frequency sensor and very high frequency sensor are installed on the transformer body and connected with the transformer monitoring device under test, the floating discharge, surface discharge, insulation paper discharge and impurity discharge are simulated, so as to determine the fault recognition accuracy of the transformer monitoring device under test. According to the test criterion "in the same cycle, the high frequency signal waveform and the very high frequency signal waveform have the same phase, and the phase difference between the high frequency signal waveform and the ultrasonic signal waveform is fixed", it is evaluated whether the synchronous acquisition and real-time display function of the transformer monitoring device under test is qualified.

[0076] Step S4, the discharge type identification function of the transformer monitoring device under test is detected.

[0077] In the implementation, the ultrasonic sensor, the high-frequency sensor and the ultra-high frequency sensor are installed on the transformer body and connected with the transformer monitoring device to be tested; a suspension fault type is selected, a preset voltage is applied to the transformer body, a fault model discharge is performed, a three-dimensional coordinate of a fault point positioned by the transformer monitoring device to be tested is recorded, a position of the three suspension discharge fault sources is changed, and a fault positioning coordinate of the comprehensive monitoring device is recorded. According to the test criterion that the fault identification accuracy of the monitoring device is not less than 60%, whether the fault identification performance of the transformer monitoring device to be tested is qualified is determined. The transformer monitoring device to be tested with the pattern recognition function should be able to judge the typical partial discharge types in the power equipment (creepage discharge, internal discharge of an insulating part, metal tip discharge, corona discharge, etc.).

[0078] In the embodiment, a flexible insulating guide pipe is arranged in the transformer body, and an implantable discharge model is arranged in the flexible insulating guide pipe, so as to guide the implantable discharge model into a high electric field area in the transformer tank and generate partial discharge.

[0079] More specifically, one end of the flexible insulating guide pipe is connected with the bushing lead in the riser, and the other end extends to the oil pillow on the top of the tank. In the embodiment, the implantation of the discharge model in the actual transformer is realized, and the partial discharge can be generated only under the condition that the transformer is pressurized and operated with electricity, so that the internal partial discharge condition of the transformer can be more truly reflected. The implantation of the discharge source in the transformer, the actual pressurization and self-excitation of the transformer, and the real implementation of the simulation of the internal partial discharge fault of the transformer are realized. The partial discharge defect model simulates four types of discharge, which are suspension discharge, creepage discharge, insulating paper discharge and impurity discharge. The discharge model can be placed at the bushing lead or in the riser. In practice, the discharge trend (initiation-development-breakdown) can be simulated by adjusting the system voltage, and the discharge model can be replaced when it is damaged.

[0080] In step S5, the discharge source fault positioning function of the transformer monitoring device to be tested is detected.

[0081] In the implementation, the step includes the following sub-steps.

[0082] In sub-step S51, the ultrasonic sensor, the high-frequency sensor and the ultra-high frequency sensor are installed on the transformer body and connected with the transformer monitoring device to be tested.

[0083] In sub-step S52, the transformer monitoring device is placed on a single-point grounded metal plate with ground insulation and is operated with electricity.

[0084] In sub-step S53, the output voltage waveform and amplitude of the steep impulse wave generator are adjusted, and the steep wave impulse voltage is applied to the tank outer wall of the transformer body for multiple times.

[0085] According to the test criterion "the fault positioning accuracy of the monitoring device is less than or equal to 20 cm", whether the fault positioning performance of the monitoring device of the transformer to be monitored is qualified is determined.

[0086] In step S6, the ground potential rise resistance function of the monitoring device of the transformer to be monitored is detected.

[0087] Referring to Figure 6 In specific implementation, the test is performed according to the following steps:

[0088] The ultrasonic sensor, the high-frequency sensor and the ultra-high frequency sensor are installed on the transformer body and connected with the monitoring device of the transformer to be monitored;

[0089] The transformer monitoring device is placed on a metal flat plate insulated from the ground and single-point grounded, and is operated to ensure that the sensor, the monitoring host and the communication network equipment are in a normal working state;

[0090] The output voltage waveform and amplitude of the steep impulse generator are adjusted, and the steep impulse voltage is applied to the outer wall of the box of the transformer body for multiple times. In the test, the steep impulse voltage wave head voltage amplitude is required to be 20 kV, the wave head time is not greater than 500 ns, and the steep impulse voltage is applied to the simulated box shell for 8 times. It is required that the data signal of the monitoring device (including the sensor) is stable, and the communication network is in a normal working state.

[0091] In step S7, the sealing function of the ultra-high frequency sensor of the monitoring device of the transformer to be monitored is detected.

[0092] Specifically, the ultra-high frequency sensor is installed on the flange interface reserved on the transformer body and connected with the monitoring device of the transformer to be monitored; the transformer body is vacuumized to a pressure lower than 0.3 kPa; the valve connected with the vacuum pump is closed, the vacuum value P1 is read after a first preset time length, and the vacuum value P2 is read after a second preset time length; whether the sealing is qualified is determined according to the difference between the two air pressure values.

[0093] Apparently, it can be concluded that the present application can detect the following functions of the transformer monitoring device: multi-parameter synchronous acquisition, multi-parameter synchronous real-time display function; high-frequency, ultra-high frequency partial discharge phase distribution map (PRPD), pulse sequence phase distribution map (PRPS) function detection; high-frequency pulse waveform polarity comparison analysis function detection; high-frequency signal time-frequency separation classification function detection; high-frequency, ultrasonic, ultra-high frequency and other monitoring anti-external interference ability function detection; discharge type identification function detection; discharge source fault positioning accuracy function detection; fault early warning, alarm and data playback function detection. Through the above function detection, the overall function of the transformer monitoring device can be evaluated, and the effectiveness of the online monitoring of the transformer is improved.

[0094] The method further comprises: step 8, detecting the high-frequency signal time-frequency separation classification function of the transformer monitoring device to be tested.

[0095] In the implementation, the high-frequency sensor is installed on the transformer body, one end of the high-frequency interference excitation source is placed on the top of the core and the clamping member of the transformer body, the other end is placed on the bottom of the core and the clamping member, the floating fault type is selected, the preset voltage is applied to the transformer body, the discharge monitoring spectrum of the high-frequency monitoring unit is recorded, the system voltage is zeroed, the interference signal simulation generating device simulates the on-site interference signal of the ground noise, the power amplifier is adjusted so that the amplitude of the interference signal is equal to the amplitude of the partial discharge under the voltage of 50kV, the noise monitoring spectrum is recorded, the voltage of 50kV is applied to the transformer body again, the high-frequency monitoring unit of the transformer monitoring device to be tested receives the partial discharge signal and the on-site interference signal at the same time, the data separation function of the device is started, and the device can display the monitoring spectrum data of the ground noise and the discharge.

[0096] In summary, the overall performance detection method of the power transformer monitoring device provided by the application can simulate the partial discharge phenomenon of the high-fault part in the transformer by the typical structure and discharge characteristics of the transformer, can more truly reflect the internal partial discharge condition of the transformer by the way of preinstalling a flexible insulation conduit in the transformer and introducing the implantable MINI discharge model to the high electric field area of the transformer along the flexible insulation conduit and generating partial discharge under the condition that the transformer is in the state of electrified operation, and can realize the simulation of the internal partial discharge fault of the transformer by implanting the discharge source in the transformer and exciting the transformer by actual pressurization.

[0097] Obviously, those skilled in the art can make various modifications and variations to the application without departing from the spirit and scope of the application. Thus, if these modifications and variations of the application fall within the scope of the claims of the application and equivalent technologies thereof, the application also intends to include these modifications and variations.

Claims

1. A method of detecting overall performance of a power transformer monitoring device, characterized by, It comprises the following steps: Step 1, detecting the anti-interference performance of the transformer monitoring device to be tested; Step 2, detecting the discharge development trend early warning function of the transformer monitoring device to be tested; Step 3, detecting the multi-parameter synchronous acquisition and real-time display function of the transformer monitoring device to be tested; Step 4, detecting the discharge type identification function of the transformer monitoring device to be tested; Step 5, detecting the discharge source fault positioning function of the transformer monitoring device to be tested; Step 6, detecting the ground potential rise tolerance function of the transformer monitoring device to be tested; Step 7, detecting the sealing function of the ultra-high frequency sensor of the transformer monitoring device to be tested; Step 8, detecting the high-frequency signal time-frequency separation classification function of the transformer monitoring device to be tested; The step 1 uses a detector, an ultra-high frequency sensor and an abrupt pulse source generator to build a test loop to detect the ultra-high frequency partial discharge anti-interference performance of the transformer monitoring device to be tested, and the performance test is carried out according to the following steps: Step (a), an anti-interference ability test loop of the transformer ultra-high frequency monitoring system is built, a PC is responsible for controlling the pulse source to send specified pulses and communicating with the detector, and the measurement results of the detector are obtained; an abrupt pulse source is responsible for sending pulse signals of specified waveforms and specified time sequences to simulate typical discharges and typical interferences; the detector is the ultra-high frequency monitoring system to be verified, a GTEM small chamber is responsible for providing a stable and traceable electric field test environment; the ultra-high frequency sensor is placed at the window of the GTEM small chamber; Step (b), a noise sensor adopts an omnidirectional conical helical antenna and is responsible for sending noise signals to simulate environmental noise; The PC controls the pulse signal source CH1 to send discharge simulation signals, the signals are injected into the GTEM small chamber, and the pulse signal source CH2 sends interference simulation signals, which are injected into the noise sensor and radiated to the space around; Step (c), the measured instrument system is turned on, and a certain specified time test is carried out to obtain the spectrum data or pulse waveform interface in the test time; Step (d), the signal simulation channel is always turned on, and the opening and closing states of the noise simulation channel are compared, and the spectrum data or pulse waveform interface of the measured instrument can display the measured pulse signal with a signal-to-noise ratio not lower than 2:1; Step (e), steps (b)-(d) are repeated for multiple times; According to the following criterion "the monitoring system should have the ability to suppress typical narrowband interference, and the measured device can display the measured pulse signal with a signal-to-noise ratio not lower than 2:1 in the test environment with narrowband interference", whether the ultra-high frequency partial discharge anti-interference performance of the transformer monitoring device to be tested is qualified is judged. The step 1 comprises: An abrupt pulse generator and an injection capacitor are used to generate high-frequency pulse current with apparent charge Q in the test loop, and a sine signal generator Us is used to generate interference current with different frequencies through a resistor R, which is applied to the input end of the high-frequency sensor connected to the transformer monitoring device to be tested to detect the high-frequency partial discharge anti-interference performance of the transformer monitoring device to be tested; ​ ​ ​ ​ 2. The method of claim 1, wherein ​ ​ ​ ​ ​ A set of pulse signals are output by an acoustic emission system or a signal generator to monitor the transformer monitoring device Ultrasonic partial discharge anti-interference performance detection A test circuit is built by using a detector, a UHF sensor and a steep pulse source generator to detect the UHF partial discharge anti-interference performance of the transformer monitoring device A test circuit is built by using a detector, a UHF sensor and a steep pulse source generator to detect the UHF partial discharge anti-interference performance of the transformer monitoring device A test circuit is built by using an ultrasonic sensor, a high-frequency sensor and a UHF sensor to detect the anti-corona interference performance of the transformer monitoring device. The step 2 comprises:

3. The method of claim 1, wherein The ultrasonic sensor, the high-frequency sensor and the UHF sensor are installed on the transformer body and connected with the transformer monitoring device to be tested, the transformer monitoring device to be tested is powered on, the type of surface discharge fault is selected, different voltages are applied to the transformer body to make the surface discharge in three stages, i.e., the initial stage, the development stage and the breakdown stage, and the monitoring values in different stages are recorded by the transformer monitoring device to be tested and pre-alarm and alarm are given.

4. The overall performance detection method of the power transformer monitoring device according to claim 1, wherein the step 3 comprises: The ultrasonic sensor, the high-frequency sensor and the UHF sensor are installed on the transformer body and connected with the transformer monitoring device to be tested, the floating discharge is simulated, and the acoustic wave data, the high-frequency data and the UHF data are collected by the transformer monitoring device to be tested. The step 4 comprises: The high-frequency sensor and the UHF sensor are installed on the transformer body and connected with the transformer monitoring device to be tested, the floating discharge, the surface discharge, the insulation paper discharge and the impurity discharge are simulated to determine the fault recognition accuracy of the transformer monitoring device to be tested. The step 5 comprises: The ultrasonic sensor, the high-frequency sensor and the UHF sensor are installed on the transformer body and connected with the transformer monitoring device to be tested, the type of floating fault is selected, a preset voltage is applied to the transformer body, the fault model discharge is carried out, the three-dimensional coordinates of the fault point positioned by the transformer monitoring device to be tested are recorded, the position of the floating discharge fault source is changed three times, and the fault positioning coordinates of the comprehensive monitoring device are recorded.

5. The method of claim 1, wherein The step 6 comprises: The ultrasonic sensor, the high-frequency sensor and the UHF sensor are installed on the transformer body and connected with the transformer monitoring device to be tested. The transformer monitoring device is placed on a metal flat plate insulated from the ground and single-point grounded, and is powered on.

6. The method of claim 1, wherein The output voltage waveform and amplitude of the steep impulse wave generator are adjusted, and the steep wave impulse voltage is applied to the outer wall of the transformer body multiple times. The step 7 comprises: The UHF sensor is installed on the flange interface reserved on the transformer body and connected with the transformer monitoring device to be tested.

7. The method of claim 1, wherein The transformer body is vacuumized to a pressure lower than 0.3 kPa. The valve connected with the vacuum pump is closed, the vacuum value P1 is read after a first preset time, and the vacuum value P2 is read after a second preset time. Whether the sealing performance is qualified is determined according to the difference between the two pressure values. The step 8 comprises: The high-frequency sensor is installed on the transformer body, one end of the high-frequency interference excitation source is placed on the core of the transformer body, ​ ​ 8. The method of claim 1, wherein ​ ​ ​ ​ ​ ​ ​ ​ 9. The method of claim 1, wherein ​ ​ And the top of the clamp member, the other end is placed in the core and the bottom of the clamp, select the type of floating fault, the transformer body is applied to preset voltage, record high frequency monitoring unit discharge monitoring spectrum, system voltage zero, interference signal simulation device simulation ground noise field interference signal, adjust the power amplifier, make the interference signal amplitude equal to 50kV voltage under partial discharge amplitude, record noise monitoring spectrum, again to the transformer body is applied to 50kV voltage, the transformer monitoring device high frequency monitoring unit under test simultaneously receives partial discharge signal and field interference signal, the device enables data separation function, the device can display ground noise and discharge two monitoring spectrum data.

Images