Transformer (high reactor) on-line monitoring device field inspection complete device and field inspection method

Abstract

The invention belongs to the related field of on-line monitoring devices, and particularly relates to on-site inspection complete equipment and an on-site inspection method for on-line monitoring devices of large-scale oil-filled equipment such as a transformer and a high-voltage reactor, the on-site inspection complete equipment comprises an inspection host, and the inspection host integrates a function generator module, a controller module, a digital-to-analog converter, a power supply module and man-machine interaction equipment. The controller module controls the function generator modules, and each function generator module outputs various excitation signals with different amplitudes and different frequency parameters according to the requirements of the controller module. After various excitation signals are sent out by the function generator, digital quantity-analog quantity signal conversion is carried out through the digital-analog converter, the signals are converted into different level signals to be sent to the excitation sensor, and the function generator of the five types of signals is modularly designed and compactly arranged in the inspection host. The device can meet the on-site inspection of six different online monitoring devices, is high in on-site inspection efficiency, does not affect the operation of equipment, and is high in on-site operation safety.

Description

Technical Field

[0001] The present invention belongs to the field related to on-line monitoring devices, and particularly relates to a complete set of on-site inspection devices and on-site inspection methods for on-line monitoring devices of large oil-filled equipment such as transformers and high-voltage reactors. Background Art

[0002] Large oil-filled equipment such as transformers and high-voltage reactors are core equipment of the power system. Early defects inside the equipment during operation will gradually develop into major accidents such as breakdown discharge and even deflagration. Therefore, accurate perception of its operating state and early warning are crucial. With the rapid development of digital power grids, the types and quantities of various on-line monitoring devices installed on transformers, such as high-frequency partial discharge and ultrasonic partial discharge, are increasing day by day, jointly constructing an early warning platform for equipment defects. However, operating experience shows that the actual application effects of many monitoring devices are not good. The main reason is that after the current on-line monitoring devices are installed, only simple debugging is carried out. Due to technical problems such as complex on-site environments and lack of equivalent excitation methods, there is a lack of effective on-site inspection instruments and methods for the performance of monitoring devices, resulting in problems during the installation and debugging of monitoring devices not being discovered in time. After being put into operation, there are problems such as high defect rates, data distortion, and low operating reliability, and it is impossible to effectively support the accurate assessment of the operating state of transformers. It is urgent to overcome the on-site inspection technology for the installation and debugging performance of monitoring devices. Summary of the Invention

[0003] The purpose of the present invention is to provide a complete set of on-site inspection devices and on-site inspection methods for on-line monitoring devices of transformers (high-voltage reactors) in view of the problems existing in the prior art. By using a complete set of on-site inspection devices that integrate equivalent excitation of 5 types of monitoring signals including ultrasonic waves, the on-site inspection work can be completed without changing the installation state of the sensors of the on-line monitoring device to be inspected. It can meet the full coverage of on-site inspections of 6 different on-line monitoring devices, with high on-site inspection efficiency, no impact on equipment operation, and high on-site operation safety, and is very valuable for popularization.

[0004] The technical solution of the present invention is as follows: A complete set of on-site inspection devices for on-line monitoring devices of transformers (high-voltage reactors), including An inspection host, the inspection host integrates a function generator module, a controller module, a digital-to-analog converter, a power supply module, and a human-computer interaction device; the controller module can control the function generator module. According to the requirements of the controller module, each function generator module outputs various excitation signals with different amplitudes and different frequency parameters. After the various excitation signals are sent out by the function generator, they are converted from "digital quantity - analog quantity" signals through the digital-to-analog converter and transformed into different level signals to be sent to the excitation sensor. The function generators of the 5 types of signals are modularly designed and are arranged compactly inside the inspection host.

[0005] Excitation sensor group: It includes excitation sensors for five types of signals, namely ultrasonic, high-frequency current, power-frequency current, ultra-high-frequency electromagnetic wave, and vibration. It is used to receive the excitation signal from the inspection host and convert it into an equivalent physical signal to be applied to the transformer (high reactance). The level signal is converted into various equivalent excitation signals by various excitation sensors (ultrasonic, high-frequency current, ultra-high-frequency electromagnetic wave, vibration). Among them, the power-frequency current does not require digital-to-analog conversion and is directly output in the form of current. Standard sensor group: It includes five types of standard sensors corresponding to the excitation sensors, which are used to synchronously receive the excitation signal and feedback the response to the inspection host. The operator inputs the excitation signal parameters through the human-computer interaction device and provides them to the controller module. At the same time, the operator observes the real-time information such as the excitation signal output of the display and the signal response of the standard sensor. The standard sensors for five different monitoring signals are connected to the inspection host through interfaces, and after sensing various excitation signals on the transformer (high reactance), they feedback the response signal to the inspection host.

[0006] Specifically, the function generator module of the inspection host includes: Ultrasonic signal generator: It outputs pulse signals with a frequency range of 20 kHz - 100 kHz; High-frequency current signal generator: It outputs high-frequency current signals with a frequency of 1 MHz - 10 MHz; Power-frequency current signal generator: It directly outputs 50 Hz power-frequency current; Ultra-high-frequency electromagnetic wave signal generator: It outputs electromagnetic pulses with a frequency of 300 MHz - 3 GHz; Vibration signal generator: It outputs mechanical vibration signals with a frequency of 10 Hz - 1 kHz; The controller module receives parameter instructions through the human-computer interaction device and controls each signal generator to output excitation signals with specific amplitudes and frequencies.

[0007] Specifically, the excitation sensor group includes: Ultrasonic and vibration excitation sensor: A magnetic adsorption type ceramic piezoelectric probe, which is connected to the inspection host through a Q9 coaxial cable and adsorbed on the surface of the transformer body, with a distance from the sensor under test ≤ 10 cm; Power-frequency / high-frequency current excitation sensor is a wire clamp wire, fixed at both ends of the transformer grounding lead wire to form a closed current loop; Ultra-high-frequency electromagnetic wave excitation sensor is a clamping type antenna probe, installed on the transformer oil drain pipe, and arranged opposite to the sensor under test at 180°.

[0008] Specifically, the excitation sensor group includes: Ultrasonic and vibration excitation sensor: A magnetic adsorption type ceramic piezoelectric probe, which is connected to the inspection host through a Q9 coaxial cable and adsorbed on the surface of the transformer body, with a distance from the sensor under test ≤ 10 cm; Power frequency / High frequency current excitation sensor: A wire clamp type conductor is fixed at both ends of the grounding downlead of the transformer to form a closed current loop; Ultra-high frequency electromagnetic wave excitation sensor: A clamping type antenna probe is installed on the oil draining pipeline of the transformer and is arranged opposite to the sensor under test at 180°.

[0009] Specifically, the standard sensor group includes: Ultrasonic and vibration standard sensor: A magnetic adsorption type ceramic piezoelectric probe is installed at the same position as the excitation sensor, and the signal is fed back through a Q9 coaxial cable; Power frequency / High frequency current standard sensor: A high-precision closed current transformer is fixed in the grounding downlead current loop; Ultra-high frequency electromagnetic wave standard sensor: A probe with an internal antenna is clamped on the oil draining pipeline and is adjacent to the sensor under test.

[0010] Specifically, the digital-to-analog converter of the inspection host converts the digital signal into an analog level signal, where: the ultrasonic, vibration, and ultra-high frequency signals are output after digital-to-analog conversion; the power frequency current is directly output in the form of an analog current.

[0011] Specifically, the housing of the inspection host is made of a metal plate with heat dissipation holes, which has both heat dissipation and electromagnetic shielding functions.

[0012] A field inspection method for an on-line monitoring device of a transformer (high impedance), comprising the following steps: Wiring configuration inspection: An excitation sensor and a standard sensor are arranged beside the sensor of the on-line monitoring device under test to ensure that both receive the same excitation signal; Data transmission inspection: Excitation signals with different amplitudes are output to verify the data transmission function of the device under test; Sensitivity inspection: The excitation signal is adjusted, and the response values of the standard sensor and the sensor under test are compared to determine the qualification of the sensitivity; Dynamic range inspection: The excitation signal is gradually increased to verify whether the dynamic range of the device under test meets "sensitivity reference value + 40 dB"; Linearity error inspection: Based on the dynamic range reference value, the linearity errors at multiple inspection points are calculated to ensure that the errors are lower than the standard threshold.

[0013] Specifically, the sensitivity inspection step specifically includes: Recording the background values of the standard sensor and the sensor under test when the excitation signal is 0; Gradually increasing the excitation signal, when the response value of the standard sensor reaches 2 times its background value, it is determined that the response value of the sensor under test needs to be ≥ 1.5 times its background value to be qualified. Specifically, in the dynamic range inspection, the dynamic range of the device under test needs to meet: The maximum value of the response of the sensor under test is not less than 40 dB of the sensitivity reference value; The linearity error does not exceed ±5% within the range of 20% - 80% of the reference value.

[0014] The inspection host supports modular replacement, and the function generator module can be independently disassembled to adapt to different monitoring signal types.

[0015] The beneficial effects of the present invention are as follows: By integrating five types of signal excitation sensors and standard sensors, combined with a modular inspection host, synchronous excitation and response comparison of ultrasonic waves, high-frequency currents, power-frequency currents, ultra-high-frequency electromagnetic waves, and vibration signals are achieved. The inspection method covers data transmission, sensitivity, dynamic range, and linearity error inspection, significantly improving the on-site inspection efficiency and accuracy of on-line monitoring devices. The device adopts a magnetic probe and a clamping antenna design, without changing the installation state of the sensor, ensuring the safe operation of the equipment, and is suitable for comprehensive performance evaluation of large oil-filled equipment such as transformers and high reactors. Description of the Drawings

[0016] Figure 1 is a schematic diagram of the principle structure of the inspection host of the device provided by the present invention; Figure 2 is the on-site inspection wiring diagram of the high-frequency partial discharge on-line monitoring device; Figure 3 is the on-site inspection wiring diagram of the ultrasonic partial discharge on-line monitoring device (or vibration on-line monitoring device); Figure 4 is the on-site inspection wiring diagram of the iron core / clamp grounding current on-line monitoring device; Figure 5 is the on-site inspection method flow of the transformer (high reactor) on-line monitoring device. Detailed Embodiments

[0017] The technical solutions of the present invention will be described in detail below in conjunction with the drawings and specific embodiments.

[0018] Embodiment 1 As Figure 1 shown is a schematic diagram of the principle structure of the inspection host of the on-site inspection complete set of devices for the transformer (high reactor) on-line monitoring device provided in this embodiment. In this embodiment, the housing of the inspection host is made of a metal plate with heat dissipation holes, which has both heat dissipation and electromagnetic shielding functions. The on-site inspection complete set of devices for the transformer (high reactor) on-line monitoring device includes the following components: Inspection host, which integrates a function generator module, a controller module, a digital-to-analog converter, a power supply module and a human-machine interaction device; the controller module can control the function generator module, and according to the requirements of the controller module, each function generator module outputs various excitation signals with different amplitudes and different frequency parameters. After the various excitation signals are sent out by the function generator, they are converted from "digital quantity - analog quantity" signals by the digital-to-analog converter and transformed into different level signals to be sent to the excitation sensor. The function generators for 5 types of signals are modularly designed and are arranged compactly inside the inspection host. The digital-to-analog converter of the inspection host converts digital signals into analog level signals, among which: ultrasonic, vibration, and UHF signals are output after digital-to-analog conversion; power frequency current is directly output in the form of analog current.

[0019] Excitation sensor group: It includes excitation sensors for five types of signals, namely ultrasonic, high-frequency current, power frequency current, UHF electromagnetic wave, and vibration, which are used to receive the excitation signals from the inspection host and convert them into equivalent physical signals to be applied to the transformer (HV reactor). The level signals are transformed into equivalent various excitation signals by various excitation sensors (ultrasonic, high-frequency current, UHF electromagnetic wave, vibration). Among them, the power frequency current does not require digital-to-analog conversion and is directly output in the form of current. The excitation sensors for 5 types of different monitoring signals are connected to the inspection host through interfaces, receive various excitation signals provided by the function generator in the host, and feedback them to the excitation sensors. Standard sensor group: It includes five types of standard sensors corresponding to the excitation sensors, which are used to synchronously receive the excitation signals and feedback the response to the inspection host. The operator inputs the excitation signal parameters through the human-machine interaction device and provides them to the controller module, and at the same time observes the real-time information such as the output of the excitation signal and the response of the standard sensor signal on the display. The standard sensors for 5 types of different monitoring signals are connected to the inspection host through interfaces, and after sensing various excitation signals on the transformer (HV reactor), they feedback the response signals to the inspection host. Among them, the 5 types of different monitoring signals include ultrasonic, high-frequency current, power frequency current, UHF electromagnetic wave, and vibration, and on-site inspection of the performance of 6 types of on-line monitoring devices such as ultrasonic partial discharge on-line monitoring device, high-frequency partial discharge on-line monitoring device, core / clamp grounding current on-line monitoring device, UHF partial discharge on-line monitoring device, vibration on-line monitoring device, and bushing insulation on-line monitoring device (power frequency current, high-frequency current) can be carried out.

[0020] The function generator module of the inspection host includes: Ultrasonic signal generator: It outputs pulse signals with a frequency range of 20 kHz - 100 kHz; High-frequency current signal generator: It outputs high-frequency current signals with a frequency of 1 MHz - 10 MHz; Power frequency current signal generator: It directly outputs 50 Hz power frequency current; Ultra-high frequency electromagnetic wave signal generator: Outputs electromagnetic pulses with a frequency of 300 MHz - 3 GHz; Vibration signal generator: Outputs mechanical vibration signals with a frequency of 10 Hz - 1 kHz; The controller module receives parameter instructions through the human-machine interaction device and controls each signal generator to output excitation signals with specific amplitudes and frequencies.

[0021] According to different signal types, the interfaces and output forms of the excitation sensors included in the excitation sensor group are also different. The excitation sensor group includes: Ultrasonic and vibration excitation sensors: Both use magnetic adsorption ceramic piezoelectric probes, which can be adsorbed on the surface of the transformer (reactor) body and are located near the ultrasonic partial discharge under test (or vibration on-line monitoring sensor) (usually at a distance of 10 cm), ensuring that the on-line monitoring device under test can sense the excitation signal. They are connected to the corresponding excitation signal ports of the inspection host through Q9 coaxial cables, receive the excitation signals sent by the inspection host, and are ≤10 cm away from the sensor under test. Power frequency / High frequency current excitation sensors: Two 4 mm 2 clip-connected wires. One is the current signal output wire and the other is the current signal return wire. One end of the two wires is connected to the corresponding excitation signal ports on the inspection host, and the other ends of the two clip-connected wires are fixed to both ends of the grounding lead of the transformer (reactor) through clips and are distributed at both ends of the iron core / clamping piece grounding current on-line monitoring sensor (or high-frequency partial discharge on-line monitoring device sensor) under test, ensuring that the on-line monitoring device under test can sense the excitation signal and form a closed current loop.

[0022] Ultra-high frequency electromagnetic wave excitation sensors: Clamping antenna probes, which can be clamped on the oil drain pipe of the transformer (reactor) and are located opposite the ultra-high frequency partial discharge on-line monitoring sensor under test (usually the layout angle is 180°), ensuring that the on-line monitoring device under test can sense the excitation signal. The excitation sensors are connected to the corresponding excitation signal ports of the inspection host through double-shielded cables and receive the excitation signals sent by the inspection host.

[0023] Standard sensors for five different types of monitoring signals are connected to the inspection host through interfaces. After sensing various excitation signals on the transformer (reactor), they feedback the response signals to the inspection host. According to different signal types, the interfaces and receiving forms of the standard sensors in the standard sensor group are also different. The standard sensor group includes: Ultrasonic and vibration standard sensors: Magnetic adsorption ceramic piezoelectric probes, which can be adsorbed on the surface of the transformer (reactor) body, are located near the ultrasonic partial discharge excitation sensor (or vibration excitation sensor), and are connected to the corresponding response signal ports of the inspection host through Q9 coaxial cables to feedback the excitation signals sensed by the inspection host.

[0024] Power frequency / High frequency current standard sensor: A high-precision closed current transformer, fixed on the grounding lead-down wire and located on the current excitation signal loop, to ensure that the standard sensor can sense the current excitation signal.

[0025] Ultra-high frequency electromagnetic wave standard sensor: A probe with an internal antenna, clamped on the oil drainage pipeline of the transformer (HV reactor) and adjacent to the sensor under test. The standard sensor is connected to the corresponding response signal port of the inspection host through a double-shielded cable to feedback the excitation signal sensed by the inspection host.

[0026] Embodiment 2 This embodiment provides a method for on-site inspection of an on-line monitoring device for a transformer (HV reactor). The on-site inspection process of the on-line monitoring device is as Figure 5 shown, including the following steps: Wiring configuration inspection: Arrange the excitation sensor and the standard sensor beside the sensor of the on-line monitoring device under test, so that the standard sensor and the sensor of the on-line monitoring device under test can receive the same excitation signal. The inspection wiring for different types of monitoring signals is as follows Figures 2 to 4 shown. Data transmission inspection: Output 2 - 3 excitation signals of different magnitudes, observe the response of the background monitoring data of the on-line monitoring device under test, and preliminarily judge whether the data transmission of the sensor and the monitoring channel of the on-line monitoring device under test is normal. If the monitoring channel of the on-line monitoring device under test generates significantly different response signals with the excitation signal, it is considered that the data transmission function of the monitoring channel of the on-line monitoring device under test is normal. Sensitivity inspection: Adjust the excitation signal, record the response values of the standard sensor and the sensor of the on-line monitoring device under test when the excitation signal is 0 as the background value. Slowly increase the excitation signal starting from 0. When the response indication value of the standard sensor just exceeds 2 times the background value of the standard sensor, record the indication value of the monitoring channel of the sensor of the on-line monitoring device under test as the sensitivity value. If this value reaches 1.5 times the background value of the sensor of the on-line monitoring device under test, it is considered that the sensitivity of the sensor of the on-line monitoring device under test is qualified. Dynamic range inspection: Gradually and slowly increase the excitation signal uniformly, record the response values of the monitoring channel of the on-line monitoring device under test at different inspection points, and verify whether the dynamic range of the device under test meets "sensitivity reference value + 40dB". Linearity error inspection: Based on the dynamic range reference value, calculate the linearity errors at multiple inspection points to ensure that the errors are lower than the standard threshold. Take the value of "sensitivity reference value + 40dB" as the dynamic range reference value, and carry out linearity error analysis and calculation using the inspection data corresponding to the reference points of 80%, 60%, 40%, 20% etc. of this reference value. The maximum allowable linearity error does not exceed the standard specified value.

[0027] Through on-site inspection, the problems existing in the inspected on-line monitoring device mainly include abnormal sensor excitation response (no response, abnormally small response indication value, abnormally large response indication value, poor response linear relationship), incorrect sensor background number, no spectrum map in the background, etc. The main reasons for the above problems include hardware defects of the sensor itself, poor contact caused by the installation process of the sensor, drying and failure of the coupling agent, improper background debugging (the front-end sensor number does not correspond to the background number, improper setting of the sensor gain parameter, the background spectrum map function is not enabled), background board card failure, signal communication interruption, etc.

[0028] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: still modifications can be made to the specific implementation manners of the present invention or equivalent replacements can be made to some technical features; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. On-site inspection complete set of devices for on-line monitoring devices of transformers (high-reactance), characterized in that, include A test host, wherein the test host integrates a function generator module, a controller module, a digital-to-analog converter, a power supply module and a human-computer interaction device; Excitation sensor group: contains five types of excitation sensors, including ultrasonic, high-frequency current, power-frequency current, ultra-high-frequency electromagnetic wave, and vibration. It is used to receive the excitation signal of the inspection host and convert it into an equivalent physical signal to be applied to the transformer (high impedance); Standard sensor group: includes five types of standard sensors corresponding to the excitation sensors, which are used to synchronously receive the excitation signal and feed back the response to the inspection host.

2. The on-site inspection complete set of devices for the on-line monitoring device of the transformer (high reactance) according to claim 1, characterized in that, The function generator module of the inspection host comprises: Ultrasonic signal generator: output pulse signal with frequency range of 20kHz-100kHz; High frequency current signal generator: output high frequency current signal with frequency of 1MHz-10MHz; Power frequency current signal generator: directly output 50Hz power frequency current; Ultra-high frequency electromagnetic wave signal generator: outputs electromagnetic pulses with a frequency of 300MHz-3GHz; Vibration signal generator: outputs mechanical vibration signals with a frequency of 10Hz-1kHz; The controller module receives parameter instructions through the human-computer interaction device and controls each signal generator to output an excitation signal with a specific amplitude and frequency.

3. The on-site inspection complete set of devices for the on-line monitoring device of the transformer (HV shunt reactor) according to claim 1, characterized in that, The excitation sensor group comprises: Ultrasonic and vibration excitation sensor: Magnetic ceramic piezoelectric probe, connected to the inspection host through Q9 coaxial cable, adsorbed on the surface of the transformer body, ≤10cm away from the sensor to be inspected; Power frequency / high frequency current excitation sensor: with wire clamp conductor, fixed at both ends of the transformer grounding lead to form a closed current loop; Ultra-high frequency electromagnetic wave excitation sensor: A clamp-type antenna probe is installed in the transformer oil drain pipe and is arranged 180° opposite to the sensor being tested.

4. The on-site inspection complete set of devices for the on-line monitoring device of the transformer (high reactance) according to claim 1, characterized in that, The standard sensor set includes: Ultrasonic and vibration standard sensor: Magnetic ceramic piezoelectric probe, installed at the same position as the excitation sensor, feedback signal through Q9 coaxial cable; Power frequency / high frequency current standard sensor: high-precision closed-end current transformer, fixed in the grounding down conductor current loop; UHF electromagnetic wave standard sensor: a probe with a built-in antenna, clamped in the oil discharge pipe and adjacent to the sensor being tested.

5. The on-site inspection complete set of devices for the on-line monitoring device of the transformer (high reactance) according to claim 1, characterized in that, The digital-to-analog converter of the test host converts the digital signal into an analog level signal, wherein: Ultrasonic, vibration, and UHF signals are output after digital-to-analog conversion; industrial frequency current is directly output in the form of analog current.

6. The on-site inspection kit for the on-line monitoring device of the transformer (HV shunt reactor) according to claim 1, characterized in that, The housing of the inspection host is made of a metal plate with heat dissipation holes, which has both heat dissipation and electromagnetic shielding functions.

7. A field inspection method for an on-line monitoring device of a transformer (high reactance), characterized in that, The steps include: Wiring configuration inspection: Place the excitation sensor and standard sensor next to the sensor of the online monitoring device to be inspected to ensure that they receive the same excitation signal; Data transmission inspection: Output excitation signals of different amplitudes to verify the data transmission function of the device under inspection; Sensitivity test: adjust the excitation signal, compare the response values of the standard sensor and the sensor under test, and determine the sensitivity qualification; Dynamic range test: gradually increase the excitation signal to verify whether the dynamic range of the device under test meets the "sensitivity reference value + 40dB"; Linearity error check: Based on the dynamic range reference value, the linearity error of multiple check points is calculated to ensure that the error is lower than the standard threshold.

8. The on-site inspection method according to claim 7, characterized in that, The specific steps for sensitivity inspection are as follows: Record the background values of the standard sensor and the sensor under test when the excitation signal is 0; Gradually increase the excitation signal. When the response value of the standard sensor reaches twice its background value, it is determined that the response value of the sensor under test needs to be ≥ 1.5 times its background value to be qualified.

9. The on-site inspection method according to claim 7, wherein In the dynamic range inspection, the dynamic range of the device under test needs to meet: The maximum value of the response value of the sensor under test is not less than 40 dB of the sensitivity reference value; The linearity error does not exceed ±5% within the range of 20% - 80% of the reference value.

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