Signal wireless transmission detection device and method for transformer partial discharge test

Abstract

The invention provides a signal wireless transmission detection device for a transformer partial discharge test, and the device comprises a test circuit which comprises an impedance detection circuit, and the input end and the output end of the impedance detection circuit are connected with a low-voltage winding and a high-voltage bushing tap of a tested transformer respectively. The impedance detection circuit comprises a signal acquisition circuit and a signal transmitting module which are connected with each other; and the partial discharge analysis circuit comprises a partial discharge analyzer and a signal receiving module which are in signal connection, and the signal receiving module receives the signal output by the signal transmitting module and transmits the signal to the partial discharge analyzer. According to the invention, a high-precision and high-efficiency detection process can be carried out on a real partial discharge signal in the transformer in a wireless transmission mode. Compared with a conventional detection method at the present stage, the method has the advantages of being wide in application range, high in controllability, high in response speed, long in service life, convenient to operate, stable, safe and the like, and a new thought is provided for partial discharge signal detection of the transformer.

Description

Technical Field

[0001] The invention relates to the technical field of detection circuits, and in particular to a signal wireless transmission detection device and method for a transformer partial discharge test. Background Art

[0002] In the power system, the stable operation of the transformer is one of the key factors to ensure the reliability of the power grid. However, in the long-term operation of the transformer, due to the aging of the internal insulation material, temperature changes, mechanical vibration and other factors, it may cause defects such as bubbles, tip burrs and suspended discharge points to form inside. These defects will cause partial discharge, which will potentially threaten the normal operation of the transformer. In order to effectively monitor and diagnose these internal defects, the transformer partial discharge test has become an indispensable detection method in the power system.

[0003] At present, the pulse current method is one of the mainstream technologies for partial discharge testing of transformers. This method connects the detection impedance of the transformer and the partial discharge analyzer, and uses the coaxial cable with a BNC connector to transmit the pulse current signal, thereby realizing accurate detection of partial discharge inside the transformer. However, the existing test wiring technology has certain limitations, mainly manifested in the extremely strict quality requirements for coaxial cables. Under the influence of external force damage, fatigue aging caused by long-term use and other factors, the cable is prone to internal core wire breakage or external insulation fatigue wear, which will not only lead to the loss of test data, but may even cause a complete interruption of the test, seriously affecting the reliability of power supply.

[0004] In addition, due to these inherent defects of coaxial cables, the cost of maintaining and replacing cables also increases accordingly, which not only increases the operating cost of the power system, but also reduces the detection efficiency. Therefore, the existing transformer partial discharge test wiring method has encountered many challenges in practical applications, and an alternative detection technology is urgently needed. Summary of the invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problem of limited application scope of wiring detection in the prior art and to provide a signal wireless transmission detection device and method for transformer partial discharge test.

[0006] To solve the above technical problems, the present invention provides a signal wireless transmission detection device for a transformer partial discharge test, which comprises: a test circuit, wherein the test circuit comprises an impedance detection circuit, wherein the input end of the impedance detection circuit is connected to the low-voltage winding of the tested transformer, and the output end of the impedance detection circuit is connected to the high-voltage bushing end screen of the tested transformer, wherein the impedance detection circuit comprises a signal acquisition circuit and a signal transmission module connected to each other, wherein the signal acquisition circuit acquires a pulse discharge signal inside the tested transformer and transmits the pulse discharge signal to the signal transmission module; and a partial discharge analysis circuit, wherein the partial discharge analysis circuit comprises a partial discharge analyzer and a signal receiving module, wherein the partial discharge analyzer and the signal receiving module are signal-connected, wherein the signal receiving module receives the signal output by the signal transmission module and transmits it to the partial discharge analyzer.

[0007] In one embodiment of the present invention, the test circuit also includes a system power supply and a coupling capacitor group connected to each other, the coupling capacitor group includes a partial discharge test coupling capacitor and a detection impedance coupling capacitor, wherein the impedance detection circuit is arranged in series with the partial discharge test coupling capacitor and in parallel with the detection impedance coupling capacitor.

[0008] In one embodiment of the present invention, the impedance detection circuit also includes a detection battery and an impedance filtering module, and the impedance filtering module, the signal acquisition module and the signal transmitting module are all connected to the detection battery, wherein the signal transmitting module and the impedance filtering module are arranged in series, and are both arranged in parallel with the signal acquisition module.

[0009] In one embodiment of the present invention, the partial discharge analyzer includes a main body and a display screen, wherein the display screen is connected to the main body, and a signal receiving interface is provided on the main body, wherein the signal receiving interface is connected to the signal receiving module.

[0010] In one embodiment of the present invention, the partial discharge analysis circuit further includes an analyzer power supply, and the main body is further provided with a voltage-stabilized power supply interface, and the voltage-stabilized power supply interface is connected to the analyzer power supply.

[0011] In one embodiment of the present invention, the partial discharge analysis circuit further includes a filter, and the filter is arranged between the signal receiving module and the partial discharge analyzer.

[0012] In one embodiment of the present invention, the signal acquisition circuit is an RC series-parallel circuit.

[0013] The present invention also provides a signal wireless transmission detection method for a transformer partial discharge test, which uses the above-mentioned signal wireless transmission detection device for the transformer partial discharge test to perform signal wireless transmission detection for the transformer partial discharge test, and comprises: step S1, exposing the low-voltage winding of the tested transformer and connecting it to the input end of the impedance detection circuit, and connecting the high-voltage bushing end screen of the tested transformer to the output end of the impedance detection circuit; step S2, supplying power to the impedance detection circuit and increasing the voltage of the medium and low voltage windings of the tested transformer. In this process, the internal pulse discharge signal of the tested transformer is collected by the signal acquisition circuit and transmitted to the signal receiving module of the partial discharge analysis circuit; step S3, program processing is performed on the pulse signal received by the signal receiving module, so that the transformer partial discharge parameter is converted into a partial discharge spectrum signal, and the result is fed back through the partial discharge analyzer.

[0014] In one embodiment of the present invention, step S2 specifically includes: supplying power to the impedance detection circuit and increasing the voltage of the medium and low voltage windings of the tested transformer. At this time, in this process, the internal pulse discharge signal of the tested transformer is collected by the signal acquisition circuit, and the signal is amplified by the filter processor and then transmitted to the signal receiving module of the partial discharge analysis circuit.

[0015] In one embodiment of the present invention, in step S3, the filter cutoff frequency of the partial discharge signal can be set by the partial discharge analyzer, and the filter cutoff frequency adjustment signal is transmitted from the partial discharge analyzer to the signal receiving module; the program processing includes decoding and image recognition processing.

[0016] The above technical solution of the present invention has the following advantages compared with the prior art: The signal wireless transmission detection device and method for the transformer partial discharge test described in the present invention collects and transmits the internal pulse discharge signal of the tested transformer through the test circuit, and then performs signal detection analysis and feedback through the partial discharge analysis circuit, thereby being able to perform a high-precision and high-efficiency detection process of the real partial discharge signal inside the transformer through wireless transmission. Compared with the conventional detection methods at this stage, the present application has the advantages of wide application range, high controllability, fast response speed, long service life, easy operation, stability and safety, etc., providing a new idea for the partial discharge signal detection of the transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0018] Figure 1 is a circuit diagram of a signal wireless transmission detection device for transformer partial discharge test in a preferred embodiment of the present invention; Figure 2 yes Figure 1 The circuit diagram of the test circuit in the signal wireless transmission detection device for transformer partial discharge test shown; Figure 3 yes Figure 1 The circuit diagram of the partial discharge analysis circuit in the signal wireless transmission detection device for the transformer partial discharge test is shown.

[0019] Explanation of the reference numerals in the specification: 100, test circuit; 110, system power supply; 120, coupling capacitor group; 121, partial discharge test coupling capacitor; 122, detection impedance coupling capacitor; 130, impedance detection circuit; 131, detection battery; 132, signal acquisition circuit; 133, impedance filtering module; 134, signal transmission module; 200, partial discharge analysis circuit; 210, partial discharge analyzer; 211, main body; 212, display screen; 213, signal receiving interface; 214, regulated power supply interface; 220, signal receiving module; 230, filter; 240, analyzer power supply; 300, tested transformer. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention. Embodiment 1

[0021] See also Figure 1 As shown, this embodiment provides a signal wireless transmission detection device for a transformer partial discharge test, which includes: a test circuit 100, the test circuit 100 includes an impedance detection circuit 130, the input end of the impedance detection circuit 130 is connected to the low-voltage winding of the tested transformer 300, the output end of the impedance detection circuit 130 is connected to the high-voltage bushing end screen of the tested transformer 300, the impedance detection circuit 130 includes a signal acquisition circuit 132 and a signal transmission module 134 connected to each other, wherein the signal acquisition circuit 132 collects the internal pulse discharge signal of the tested transformer 300 and transmits the pulse discharge signal to the signal transmission module 134; a partial discharge analysis circuit 200, the partial discharge analysis circuit 200 includes a partial discharge analyzer 210 and a signal receiving module 220, the partial discharge analyzer 210 and the signal receiving module 220 are signal-connected, wherein the signal receiving module 220 receives the signal output by the signal transmission module 134 and transmits it to the partial discharge analyzer 210.

[0022] The signal wireless transmission detection device for the transformer partial discharge test described in this embodiment collects and transmits the internal pulse discharge signal of the tested transformer 300 through the test circuit 100, and then performs signal detection analysis and feedback through the partial discharge analysis circuit 200, thereby being able to perform a high-precision and high-efficiency detection process of the real partial discharge signal inside the transformer through wireless transmission. Compared with the conventional detection methods at this stage, this application has the advantages of wide application range, high controllability, fast response speed, long service life, easy operation, stability and safety, etc., and provides a new idea for the partial discharge signal detection of the transformer.

[0023] See also Figure 1 As shown, the test circuit 100 in this embodiment is connected to the partial discharge analysis circuit 200 through a signal. Specifically, this embodiment uses WIFI signals for data transmission. In different implementations, it can also be configured as other wireless transmission methods, and the present invention does not make specific restrictions on this. Among them, the test circuit 100 is used to connect the tested transformer 300, and implement signal acquisition by changing the voltage on the low-voltage winding of the tested transformer 300. It can perform signal conversion while acquiring, and transmit the signal carrying the change information to the partial discharge analysis circuit 200, and then the partial discharge analysis circuit 200 processes and feeds back the signal. Based on the above structure, the operator can intuitively realize real-time monitoring of the internal discharge of the tested transformer 300 according to the signal displayed by the partial discharge analyzer 210.

[0024] Specifically, the test circuit 100 in this embodiment also includes a system power supply 110 and a coupling capacitor group 120 connected to each other, and the coupling capacitor group 120 includes a partial discharge test coupling capacitor 121 and a detection impedance coupling capacitor 122, wherein the impedance detection circuit 130 is arranged in series with the partial discharge test coupling capacitor 121, and is arranged in parallel with the detection impedance coupling capacitor 122. Based on the above structure, the partial discharge test coupling capacitor 121 and the detection impedance coupling capacitor 122 can transfer the signal generated by the partial discharge from the high voltage side to the low voltage side for detection and analysis, and at the same time, it can also prevent the noise or interference signal of the test power supply from affecting the detection of the partial discharge signal, thereby improving the accuracy of the signal detection.

[0025] See also Figure 1 and Figure 2As shown, the signal acquisition circuit 132 in this embodiment is an RC series-parallel circuit, thereby improving the matching degree between it and the internal impedance of the tested transformer 300. Further, it also includes a detection battery 131 and an impedance filtering module 133, wherein the impedance filtering module 133, the signal acquisition module and the signal transmitting module 134 are all connected to the detection battery 131, wherein the signal transmitting module 134 is arranged in series with the impedance filtering module 133, and both are arranged in parallel with the signal acquisition module. Among them, the detection battery 131 adopts a 12V DC battery, which is used to power the signal acquisition circuit 132 and the signal transmitting module 134, and the signal transmitting module 134 is preferably a WIFI signal transmitter, which is used to transmit the received partial discharge signal and discharge spectrum with the tested transformer 300 to the partial discharge analysis circuit 200, and the impedance filtering module 133 is used to remove the redundant frequency components in the signal to improve the signal transmission quality. Further, in this embodiment, the impedance filtering can be parameter-adjusted by the partial discharge analyzer 210.

[0026] See also Figure 1 and Figure 3 As shown, the partial discharge analyzer 210 in this embodiment includes a body 211 and a display screen 212. The display screen 212 is connected to the body 211. The body 211 is provided with a signal receiving interface 213. The signal receiving interface 213 is connected to the signal receiving module 220. Among them, the signal analysis and processing structure is set in the body 211, and the display screen 212 is used to display the test results after signal conversion. In this embodiment, it can present the partial discharge value of the transformer and the partial discharge spectrum signal. Specifically, the selection of the filter function and the setting of the filter bandwidth can be completed on the visual interface of the display screen 212.

[0027] Based on this, the partial discharge analysis circuit in this embodiment further includes a filter 230 and an analyzer power supply 240, wherein the filter 230 is arranged between the signal receiving module 220 and the partial discharge analyzer 210, and the body 211 is further provided with a stabilized power supply interface 214, and the stabilized power supply interface 214 is connected to the analyzer power supply 240. Specifically, the analyzer power supply 240 is preferably a 12V DC stabilized power supply, which is used to power the signal receiving module 220 and the partial discharge analyzer 210, and the filter 230 is used to improve the signal transmission quality in the partial discharge analysis circuit 200. Embodiment 2

[0028] This embodiment provides a signal wireless transmission detection method for a transformer partial discharge test, which uses the signal wireless transmission detection device for a transformer partial discharge test described in Embodiment 1 to perform signal wireless transmission detection for a transformer partial discharge test, and includes: Step S1, exposing the low voltage winding of the tested transformer 300 and connecting it to the input end of the impedance detection circuit 130, and connecting the high voltage bushing end screen of the tested transformer 300 to the output end of the impedance detection circuit 130; Step S2, supplying power to the impedance detection circuit 130, and increasing the voltage of the low-voltage winding of the tested transformer 300 at the same time. In this process, the internal pulse discharge signal of the tested transformer 300 is collected by the signal acquisition circuit 132, and transmitted to the signal receiving module 220 of the partial discharge analysis circuit 200; further, in this embodiment, step S2 is specifically: supplying power to the impedance detection circuit 130, and increasing the voltage of the low-voltage winding of the tested transformer 300 at the same time. At this time, in this process, the internal pulse discharge signal of the tested transformer 300 is collected by the signal acquisition circuit 132, and transmitted to the signal receiving module 220 of the partial discharge analysis circuit 200 after signal amplification processing by the filter processor.

[0029] Step S3, program processing is performed on the pulse signal received by the signal receiving module 220, so that the transformer partial discharge parameters are converted into partial discharge spectrum signals, and the result is fed back through the partial discharge analyzer 210. Further, in this embodiment, the filter cutoff frequency of the partial discharge signal can be set by the partial discharge analyzer 210, and the filter cutoff frequency adjustment signal is transmitted from the partial discharge analyzer 210 to the signal receiving module 220; the program processing includes decoding and image recognition processing. Furthermore, in different implementations, the program processing can also include other processing processes, and the present invention does not specifically limit this.

[0030] In summary, the signal wireless transmission detection device and method for the transformer partial discharge test described in the present invention collects and transmits the internal pulse discharge signal of the tested transformer 300 through the test circuit 100, and then performs signal detection analysis and feedback through the partial discharge analysis circuit 200, thereby being able to perform a high-precision and high-efficiency detection process of the real partial discharge signal inside the transformer through wireless transmission. Compared with the conventional detection methods at this stage, the present application has the advantages of wide application range, high controllability, fast response speed, long service life, easy operation, stability and safety, etc., and provides a new idea for the partial discharge signal detection of transformers.

[0031] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A signal wireless transmission detection device for transformer partial discharge test, characterized in that: include: A test circuit, wherein the test circuit comprises an impedance detection circuit, wherein the input end of the impedance detection circuit is connected to the low-voltage winding of the tested transformer, and the output end of the impedance detection circuit is connected to the high-voltage bushing end screen of the tested transformer, and the impedance detection circuit comprises a signal acquisition circuit and a signal transmission module which are connected to each other, wherein the signal acquisition circuit acquires a pulse discharge signal inside the tested transformer and transmits the pulse discharge signal to the signal transmission module; A partial discharge analysis circuit, the partial discharge analysis circuit comprises a partial discharge analyzer and a signal receiving module, the partial discharge analyzer and the signal receiving module are signal-connected, wherein the signal receiving module receives the signal output by the signal transmitting module and transmits it to the partial discharge analyzer.

2. The signal wireless transmission detection device for transformer partial discharge test according to claim 1 is characterized in that: The test circuit also includes a system power supply and a coupling capacitor group connected to each other, and the coupling capacitor group includes a partial discharge test coupling capacitor and a detection impedance coupling capacitor, wherein the impedance detection circuit is arranged in series with the partial discharge test coupling capacitor and in parallel with the detection impedance coupling capacitor.

3. The signal wireless transmission detection device for transformer partial discharge test according to claim 1 is characterized in that: The impedance detection circuit also includes a detection battery and an impedance filtering module. The impedance filtering module, the signal acquisition module and the signal transmitting module are all connected to the detection battery, wherein the signal transmitting module and the impedance filtering module are arranged in series, and are both arranged in parallel with the signal acquisition module.

4. The signal wireless transmission detection device for transformer partial discharge test according to claim 1 is characterized in that: The partial discharge analyzer includes a main body and a display screen, wherein the display screen is connected to the main body, and a signal receiving interface is provided on the main body, wherein the signal receiving interface is connected to the signal receiving module.

5. The signal wireless transmission detection device for transformer partial discharge test according to claim 4 is characterized in that: The partial discharge analysis circuit also includes an analyzer power supply, and the main body is also provided with a voltage-stabilized power supply interface, and the voltage-stabilized power supply interface is connected to the analyzer power supply.

6. The signal wireless transmission detection device for transformer partial discharge test according to claim 1 is characterized in that: The partial discharge analysis circuit further includes a filter, and the filter is arranged between the signal receiving module and the partial discharge analyzer.

7. The signal wireless transmission detection device for transformer partial discharge test according to claim 1 is characterized in that: The signal acquisition circuit is an RC series-parallel loop.

8. A signal wireless transmission detection method for transformer partial discharge test, characterized in that: The signal wireless transmission detection device for transformer partial discharge test according to any one of claims 1 to 7 is used to perform signal wireless transmission detection for transformer partial discharge test, which comprises: Step S1, exposing the low-voltage winding of the tested transformer and connecting it to the input end of the impedance detection circuit, and connecting the high-voltage bushing end screen of the tested transformer to the output end of the impedance detection circuit; Step S2, supplying power to the impedance detection circuit and increasing the voltage of the medium and low voltage windings of the tested transformer at the same time. During this process, the internal pulse discharge signal of the tested transformer is collected by the signal acquisition circuit and transmitted to the signal receiving module of the partial discharge analysis circuit; Step S3, program processing is performed on the pulse signal received by the signal receiving module to convert the transformer partial discharge parameter into a partial discharge spectrum signal, and the result is fed back through the partial discharge analyzer.

9. The signal wireless transmission detection method for transformer partial discharge test according to claim 8 is characterized in that: Step S2 is specifically as follows: supplying power to the impedance detection circuit and increasing the voltage of the medium and low voltage windings of the tested transformer at the same time. At this time, in this process, the internal pulse discharge signal of the tested transformer is collected by the signal acquisition circuit, and the signal is amplified by the filter processor and then transmitted to the signal receiving module of the partial discharge analysis circuit.

10. The signal wireless transmission detection method for transformer partial discharge test according to claim 8, characterized in that: In step S3, the filter cutoff frequency of the partial discharge signal can be set by the partial discharge analyzer, and the filter cutoff frequency adjustment signal is transmitted from the partial discharge analyzer to the signal receiving module; the program processing includes decoding and image recognition processing.

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