Self-calibration GIS partial discharge detection device based on LC sensor

Abstract

This invention provides a self-calibrating GIS partial discharge detection device based on an LC sensor. The device includes an LC sensor probe, a readout circuit module, a calibration module, and a signal processing module. In partial discharge detection mode, both coils simultaneously receive partial discharge signals, generating an induced voltage at the LC sensor. This induced voltage is read by the readout circuit system, and analysis of the obtained voltage detects the occurrence and type of partial discharge. In calibration mode, a standard discharge pulse signal is generated by the calibration system and transmitted from the calibration signal transmitting coil to the sensor coil via inductive coupling. This signal is read by the readout circuit, and comparison with the standard partial discharge signal completes the device calibration, thus eliminating detection errors caused by sensor aging.

Description

Technical Field

[0001] The invention belongs to the technical field of LC sensors, and in particular relates to a self-calibration GIS partial discharge detection device and method based on an LC sensor. Background Art

[0002] Gas Insulated Substation GIS (Gas Insulated Substation) is widely used in high voltage and ultra-high voltage transmission systems. GIS equipment has high reliability, but once a fault occurs inside the GIS equipment, the strong closedness and complex internal structure of the GIS equipment make it difficult to accurately find and determine the location of the fault.

[0003] Among all the fault types that occur in GIS equipment, faults caused by insulation problems are the most common. Partial discharge is an important factor that induces insulation degradation or even insulation failure in GIS equipment, which will further deepen the degree of surface degradation and cause insulation failure.

[0004] Existing wireless partial discharge detection devices require the sensor probe to be installed inside the GIS. The maintenance cycle of GIS equipment is long, the maintenance cost is high, and it is difficult to replace the sensor. The sensor is required to work stably for a long time. However, as the working time of the equipment increases, the sensor device will inevitably age, resulting in errors in the detection and reducing the detection accuracy. Therefore, a partial discharge detection method that can achieve self-calibration is needed. Summary of the invention

[0005] The purpose of the present invention is to address the shortcomings of the above-mentioned background technology, solve the problem that the detection signal in the traditional LC sensor partial discharge detection method will be affected by the aging of the sensor device and affect the detection accuracy, and provide a self-calibration GIS partial discharge detection device based on LC sensor;

[0006] In order to achieve the above object, the present invention adopts the following technical scheme: a self-calibration GIS partial discharge detection device based on LC sensor, characterized in that it comprises: an LC sensor probe, a readout circuit module, a calibration module and a signal processing module;

[0007] The LC sensor probe comprises a sensor inductor and a calibration inductor, the sensor inductor and the calibration inductor are connected in series, the LC sensor probe is arranged inside the GIS metal box, and the sensor inductor is used to collect partial discharge signals inside the GIS metal box;

[0008] The readout circuit module includes a readout inductor and a fast signal acquisition circuit. The readout inductor is connected to the fast signal acquisition circuit. Signals are transmitted between the sensor inductor and the readout inductor through inductive coupling. The readout circuit module is arranged outside the GIS metal box.

[0009] The calibration module includes a calibration signal transmitting coil and a standard discharge pulse generating circuit, the calibration signal transmitting coil is connected to the standard discharge pulse generating circuit, the calibration inductor coil and the calibration signal transmitting coil transmit signals through inductive coupling, and the calibration module is arranged outside the GIS metal box;

[0010] In the partial discharge detection mode, the signal processing module is used to obtain the type of partial discharge according to the output signal of the fast signal acquisition circuit in the partial discharge detection mode; in the calibration mode, the standard discharge pulse generating circuit is used to output a standard partial discharge signal, and the signal processing module is used to compare the output signal of the fast signal acquisition circuit in the calibration mode with the standard partial discharge signal to obtain a detection error, and the detection error is used to calibrate the output of the fast signal acquisition circuit in the partial discharge detection mode in the partial discharge detection mode.

[0011] Furthermore, the signal processing module obtains the type of the partial discharge by matching the phase and amplitude of the output signal of the fast signal acquisition circuit in the partial discharge detection mode with the known partial discharge type.

[0012] Furthermore, the standard discharge pulse generating circuit generates the standard partial discharge signal at a preset period timing.

[0013] Beneficial effects:

[0014] 1. Compared with other GIS partial discharge detection devices, the self-calibration GIS partial discharge detection device based on LC sensor of the present invention has a calibration function, which can effectively improve the detection accuracy;

[0015] 2. The sensor probe of the present invention can be placed inside the GIS sensor for a long time, and the error caused by device aging can be eliminated through the calibration mode, thus extending the service life of the equipment;

[0016] 3. The present invention can place the sensor probe inside the GIS equipment to achieve wireless signal transmission and online detection of partial discharge;

[0017] 4. The LC sensor probe of the present invention is composed of two inductor coils connected in series and has a simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1This is an equivalent circuit diagram of a GIS partial discharge detection device based on a differential LC sensor provided in Example 1.

[0019] In the figure: 1. LC sensor probe, 2. readout circuit module, 3. calibration module, 4. signal processing module, 11. sensor inductor, 12. calibration inductor 12, 21. readout inductor, 22. fast signal acquisition circuit, 31. calibration signal transmitting coil, 32. standard discharge pulse generating circuit. DETAILED DESCRIPTION

[0020] The present invention will be further explained below in conjunction with the accompanying drawings.

[0021] Example 1

[0022] like Figure 1 As shown, the self-calibration GIS partial discharge detection device based on LC sensor disclosed in the present invention includes an LC sensor probe 1, a readout circuit module 2, a calibration module 3, a signal processing module 4 and a GIS metal box.

[0023] The LC sensor probe 1 includes a sensor inductor 11 and a calibration inductor 12, wherein the sensor inductor 11 and the calibration inductor 12 are connected in series, and the LC sensor probe 1 is arranged inside the GIS metal box, and the sensor inductor 11 is used to collect partial discharge signals inside the GIS metal box;

[0024] The readout circuit module 2 includes a readout inductor 21 and a fast signal acquisition circuit 22. The readout inductor 21 is connected to the fast signal acquisition circuit 22, and the sensor inductor 11 and the readout inductor 21 are connected to each other through inductive coupling to transmit signals. The readout circuit module 2 is arranged outside the GIS metal box.

[0025] The calibration module 3 includes a calibration signal transmitting coil 31 and a standard discharge pulse generating circuit 32. The calibration signal transmitting coil 31 is connected to the standard discharge pulse generating circuit 32, and the calibration inductor 12 and the calibration signal transmitting coil 31 are transmitted by inductive coupling. The calibration module 3 is arranged outside the GIS metal box;

[0026] In the partial discharge detection mode, the signal processing module 4 is used to obtain the type of partial discharge according to the output signal of the fast signal acquisition circuit 22 in the partial discharge detection mode.

[0027] In this embodiment, in the partial discharge detection mode, when partial discharge occurs inside the GIS equipment, an electromagnetic wave signal is generated, and the signal is transmitted to the LC sensor probe 1. The sensor inductor 11 and the calibration inductor 12 simultaneously receive the signal, and an induced voltage is generated at both ends of the sensor inductor 11. Then the readout circuit module 2 reads the induced voltage on the LC sensor probe 1 through the readout inductor 21, and collects the voltage signal through the fast signal acquisition circuit 22. Finally, the phase and amplitude of the output signal of the fast signal acquisition circuit 22 in the partial discharge detection mode are matched with the known partial discharge type to obtain the discharge type of the partial discharge. The signal processing module 4 uses the existing circuit and signal processor to process the input signal.

[0028] In the calibration mode, the standard discharge pulse generating circuit 32 is used to output a standard local discharge signal, and the signal processing module 4 is used to compare the output signal of the fast signal acquisition circuit 22 in the calibration mode with the standard local discharge signal to obtain a detection error, and the detection error is used to calibrate the output of the fast signal acquisition circuit 22 in the local discharge detection mode in the local discharge detection mode.

[0029] In this embodiment, in the calibration mode, the standard discharge pulse generating circuit 32 generates a standard discharge pulse according to a preset period, and transmits it to the calibration signal transmitting coil 31, and transmits the calibration signal to the calibration inductor 12. At the same time, the standard discharge pulse generating circuit outputs a standard partial discharge signal, and transmits it to the signal processing module 4. Then the calibration inductor 12 receives the calibration signal to generate an induced voltage, and transmits the voltage signal to the sensor inductor 11. Then the readout circuit module 2 reads the induced voltage on the LC sensor probe 1 through the readout inductor 21, and collects the voltage signal through the fast signal acquisition circuit 22. Finally, the output signal of the fast signal acquisition circuit 22 at this time is transmitted to the processing module 4, and the output signal of the fast signal acquisition circuit 22 in the calibration mode is compared with the standard partial discharge signal in the processing module 4 to obtain the detection error caused by factors such as device aging, and remove this error in the subsequent partial discharge detection mode.

[0030] The device has two working modes: partial discharge detection mode and calibration mode. When working in the partial discharge detection mode, the sensor inductor 11 and the calibration inductor 12 simultaneously receive the electromagnetic wave signal generated by the partial discharge, and collect the signal through the readout circuit system 2 to complete the detection of partial discharge; when working in the calibration mode, the calibration system 3 transmits the standard partial discharge signal to the calibration inductor 12 through the calibration signal transmitting coil 31, reads the induced voltage on the sensor inductor 11 through the readout inductor 21, compares the signal with the standard partial discharge signal, and obtains the detection error caused by device aging. This error is eliminated in the subsequent partial discharge detection mode to improve the detection accuracy and service life.

[0031] The invention has strong anti-interference performance and simple structure, and can effectively reduce detection errors, improve detection accuracy and device service life.

[0032] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A self-calibrating GIS partial discharge detection device based on LC sensor, characterized in that: include: LC sensor probe (1), readout circuit module (2), calibration module (3) and signal processing module (4); The LC sensor probe (1) comprises a sensor inductor (11) and a calibration inductor (12), wherein the sensor inductor (11) and the calibration inductor (12) are connected in series, and the LC sensor probe (1) is arranged inside a GIS metal box, and the sensor inductor (11) is used to collect partial discharge signals inside the GIS metal box; The readout circuit module (2) comprises a readout inductor (21) and a fast signal acquisition circuit (22); the readout inductor (21) is connected to the fast signal acquisition circuit (22); the sensor inductor (11) and the readout inductor (21) transmit signals via inductive coupling; and the readout circuit module (2) is arranged outside a GIS metal box; The calibration module (3) comprises a calibration signal transmitting coil (31) and a standard discharge pulse generating circuit (32); the calibration signal transmitting coil (31) is connected to the standard discharge pulse generating circuit (32); the calibration inductor coil (12) and the calibration signal transmitting coil (31) transmit signals via inductive coupling; and the calibration module (3) is arranged outside the GIS metal box; In a partial discharge detection mode, the signal processing module (4) is used to obtain the type of partial discharge according to the output signal of the fast signal acquisition circuit (22) in the partial discharge detection mode; in a calibration mode, the standard discharge pulse generating circuit (32) is used to output a standard partial discharge signal, and the signal processing module (4) is used to compare the output signal of the fast signal acquisition circuit (22) in the calibration mode with the standard partial discharge signal to obtain a detection error, and the detection error is used to calibrate the output of the fast signal acquisition circuit (22) in the partial discharge detection mode in the partial discharge detection mode.

2. The self-calibration GIS partial discharge detection device based on LC sensor according to claim 1 is characterized in that: The signal processing module (4) obtains the type of partial discharge by matching the phase and amplitude of the signal output by the fast signal acquisition circuit (22) in the partial discharge detection mode with the known partial discharge type.

3. The self-calibration GIS partial discharge detection device based on LC sensor according to claim 1, characterized in that: The standard discharge pulse generating circuit (32) generates the standard partial discharge signal at a preset period timing.

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