An anti-interference partial discharge measurement device

Abstract

This invention discloses an anti-interference partial discharge measurement device, comprising a power supply module for providing DC power, a transient voltage suppression module for suppressing transient overvoltages on the power line, an LC filter network for filtering high-frequency noise, and a partial discharge detection module. The transient voltage suppression module is connected in parallel between the positive output terminal of the power supply module and ground. The LC filter network consists of an inductor and a multi-stage filter capacitor bank connected in parallel. One end of the inductor is connected to the output terminal of the transient voltage suppression module, and the other end is connected to the positive terminal of the multi-stage filter capacitor bank. The partial discharge detection module consists of a detection probe, a data processing unit, and a wireless communication module connected in sequence. The negative terminal of the multi-stage filter capacitor bank is connected to the input terminal of the detection probe. This invention significantly enhances anti-interference performance through the synergistic design of the LC filter network and the multi-stage capacitor bank, enabling accurate monitoring of partial discharge signals.

Description

Technical Field

[0001] This utility model belongs to the field of power equipment testing technology, and in particular relates to an anti-interference partial discharge measuring device. Background Technology

[0002] Partial discharge (PD) detection is an important means of assessing the insulation status of high-voltage power equipment. Especially in key equipment such as switchgear, transformers, and GIS gas-insulated switchgear, accurate monitoring of partial discharge signals can effectively prevent insulation breakdown and sudden failures.

[0003] Traditional partial discharge (PD) detection devices often employ wired connections and continuous power supply. For example, Chinese utility model patent (CN202122274684.2) discloses an ultra-energy-efficient PD measurement device, which includes a timing module that activates the PD device for detection within a set time. The input terminal of the timing module is connected to a power supply, and a first capacitor is connected in parallel between the power supply and the timing module. The positive terminal of the power supply is connected to one end of the first capacitor, and a switch is provided between the positive terminal of the power supply and the first capacitor. The output terminal of the timing module is connected to the base (B) of a first transistor. The emitter (E) of the first transistor is connected to one end of a first resistor, and the collector (C) is connected to one end of a second resistor. The other end of the first resistor is connected to the negative terminal of the power supply, and the other end of the second resistor is connected to the base (B) of a second transistor. The emitter (E) of the second transistor is connected to the positive terminal of the power supply, and the collector (C) of the second transistor is connected to one end of a second capacitor and one end of the PD device.

[0004] While the aforementioned energy-efficient partial discharge measurement device can meet basic detection requirements, it suffers from the following drawbacks in practical applications: High-voltage switchgear and other environments exhibit strong electromagnetic noise, such as arc discharge and operational overvoltage. The device's power supply and signal links lack effective filtering and protection designs, making the detection signal susceptible to contamination and increasing false alarm and false detection rates. For example, circuits relying solely on single-capacitor filtering struggle to suppress high-frequency noise, affecting the accurate extraction of partial discharge pulses. Utility Model Content

[0005] The purpose of this invention is to provide an anti-interference partial discharge measurement device that has anti-interference performance and can achieve accurate monitoring of partial discharge signals.

[0006] The objective of this utility model is achieved through the following technical measures: an anti-interference partial discharge measurement device, characterized in that it includes a power supply module for providing DC power, a transient voltage suppression module for suppressing transient overvoltages on the power line, an LC filter network for filtering high-frequency noise, and a partial discharge detection module. The transient voltage suppression module is connected in parallel between the positive output terminal of the power supply module and ground. The LC filter network consists of an inductor and a multi-stage filter capacitor bank connected in parallel. One end of the inductor is connected to the output terminal of the transient voltage suppression module, and the other end is connected to the positive terminal of the multi-stage filter capacitor bank. The partial discharge detection module consists of a detection probe, a data processing unit, and a wireless communication module connected in sequence. The negative terminal of the multi-stage filter capacitor bank is connected to the input terminal of the detection probe.

[0007] This invention significantly enhances anti-interference performance through the coordinated design of an LC filter network and a multi-stage capacitor bank, enabling accurate monitoring of partial discharge signals.

[0008] The transient voltage suppression module of this invention uses a unidirectional TVS diode, whose breakdown voltage is 1.2 to 1.5 times the power supply voltage.

[0009] The multi-stage filter capacitor bank of this invention includes a first capacitor, a second capacitor, and a third capacitor. The first capacitor is a tantalum capacitor with low equivalent series resistance and a capacitance of 10μF to 100μF. The second capacitor is a ceramic capacitor with a capacitance of 0.01μF to 1μF. The third capacitor is an electrolytic capacitor with a capacitance of 100μF to 1000μF. The inductor has an inductance of 10μH to 100μH and a rated current greater than 500mA. Together with the multi-stage filter capacitor bank, they form a low-pass filter with a cutoff frequency of less than 1MHz.

[0010] The present invention has a timing control module connected between the multi-stage filter capacitor bank and the detection probe for triggering partial discharge detection according to a preset cycle.

[0011] A switching circuit is connected between the timing control module and the detection probe of this utility model. The switching circuit consists of a first transistor, a second resistor, and a second transistor. The output terminal of the timing control module is connected to the base of the first transistor. The collector of the first transistor is connected to the base of the second transistor through the second resistor R2. The collector of the second transistor is connected to the power supply terminal of the partial discharge detection module.

[0012] In this invention, a current-limiting resistor with a resistance value of 5Ω to 50Ω is connected in series between the collector of the second transistor and the power supply terminal of the partial discharge detection module.

[0013] The timing control module of this invention has a temperature-compensated crystal oscillator (TCXO) or a network time protocol (NTP) synchronization unit for correcting clock drift.

[0014] This invention features an optically coupled isolation unit for blocking common-mode interference connected between the detection probe and the data processing unit, and the detection probe is a composite sensor integrating an ultra-high frequency (UHF) antenna and a transient ground voltage (TEV) sensor.

[0015] The data processing unit described in this invention supports over-the-air firmware upgrades and integrates with external IoT platforms through standardized communication protocols.

[0016] Compared with the prior art, the present invention has the following significant advantages:

[0017] (1) This utility model significantly enhances anti-interference performance through the coordinated design of LC filter network and multi-stage capacitor bank, and can realize accurate monitoring of partial discharge signal.

[0018] (2) This utility model's low-pass filter, composed of inductors and capacitors, has a cutoff frequency below 1MHz, effectively blocking high-frequency electromagnetic noise such as arcing interference in switch cabinets. The combined function of tantalum capacitors, ceramic capacitors, and electrolytic capacitors covers the entire frequency range from low to high frequencies. Tantalum capacitors, with their low equivalent series resistance (ESR), effectively absorb low-to-mid-frequency ripple; ceramic capacitors provide rapid bypassing for MHz-level high-frequency noise; and electrolytic capacitors smooth long-term power supply fluctuations.

[0019] (3) This utility model uses a unidirectional TVS diode as a transient voltage suppressor, which can clamp overvoltage within nanoseconds and protect the subsequent circuit from surge impact.

[0020] (4) This utility model introduces a dual transistor switching circuit and a high-precision timing module, solving the problem of continuous power consumption in traditional equipment. The timing module synchronizes with a temperature-compensated crystal oscillator (TCXO) or a network time protocol (NTP), controlling clock drift to within ±1 second per month, ensuring a strict triggering cycle similar to once a week. The transistor switching circuit is only turned on during the detection period and is completely de-energized when not in operation, with a static current of less than 1μA. Attached Figure Description

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0022] Figure 1 This is a schematic diagram of the overall structural composition of this utility model;

[0023] Figure 2 This is a schematic diagram of the composition structure of the LC filter network of this utility model;

[0024] Figure 3 This is a schematic diagram of the composition structure of the partial discharge detection module of this utility model;

[0025] Figure 4This is a schematic diagram of the composition structure of the switching circuit of this utility model. Detailed Implementation

[0026] like Figures 1-4 As shown, this utility model discloses an anti-interference partial discharge measurement device, comprising a power supply module for providing DC power, a transient voltage suppression module (TVS) for suppressing transient overvoltages on the power line, an LC filter network for filtering high-frequency noise, a timing control module for triggering partial discharge detection according to a preset cycle, a switching circuit, and a partial discharge detection module. The transient voltage suppression module is connected in parallel between the positive output terminal of the power supply module and ground. The LC filter network consists of an inductor L1 and a multi-stage filter capacitor bank connected in parallel. One end of the inductor L1 is connected to the output terminal of the transient voltage suppression module, and the other end is connected to the positive terminal of the multi-stage filter capacitor bank. The partial discharge detection module collects signals through a probe and wirelessly transmits data. The partial discharge detection module consists of a detection probe, a data processing unit, and a wireless communication module connected in sequence. The negative terminal of the multi-stage filter capacitor bank is connected to the input terminal of the detection probe.

[0027] A complete anti-interference detection link is formed: TVS protects the downstream circuit from surge damage, LC filtering suppresses electromagnetic interference, and wireless communication enables remote monitoring. The device as a whole has basic anti-interference capabilities and is suitable for high-voltage environments.

[0028] The multi-stage filter capacitor bank includes a first capacitor C1, a second capacitor C2, and a third capacitor C3. The first capacitor C1 is a tantalum capacitor with low equivalent series resistance and a capacitance of 10μF to 100μF; the second capacitor C2 is a ceramic capacitor with a capacitance of 0.01μF to 1μF; and the third capacitor C3 is an electrolytic capacitor with a capacitance of 100μF to 1000μF.

[0029] Define the parameters and types of multi-stage capacitors: Tantalum capacitors (10μF~100μF) are used for mid-to-low frequency filtering, ceramic capacitors (0.01μF~1μF) filter out high-frequency noise, and electrolytic capacitors (100μF~1000μF) smooth low-frequency ripple. Full-band noise suppression: Ceramic capacitors absorb MHz-level interference (such as arc noise), tantalum capacitors reduce mid-frequency ripple (ESR < 1Ω), and electrolytic capacitors stabilize the power supply voltage. Overall ripple ≤ 50mV ensures a pure detection signal.

[0030] The inductor L1 has an inductance value of 10μH to 100μH and a rated current greater than 500mA. Together with a multi-stage filter capacitor bank, it forms a low-pass filter with a cutoff frequency of less than 1MHz. The inductance value (10μH~100μH) and rated current (>500mA) are limited, and together with the capacitor bank, they form a low-pass filter with a cutoff frequency <1MHz.

[0031] It blocks high-frequency noise (such as electromagnetic interference caused by switching operations) while allowing partial discharge signals (typically <1MHz) to pass through, thus improving the signal-to-noise ratio. The inductor's high rated current ensures stable operation under load fluctuations.

[0032] A timing control module and a switching circuit are connected sequentially between the multi-stage filter capacitor bank and the detection probe. The timing control module triggers detection according to a preset cycle and controls the power supply through the switching circuit. This achieves an intermittent operating mode: power is supplied only during the detection period, and completely de-energized during non-operational periods, with static power consumption <1μA and battery life extended from 1 year to 3-4 years. The switching circuit consists of a first transistor, a second resistor R2, and a second transistor. The output of the timing control module is connected to the base of the first transistor, and the collector of the first transistor is connected to the base of the second transistor through the second resistor R2. The collector of the second transistor is connected to the power supply terminal of the partial discharge detection module. The first transistor drives the second transistor, controlling the switching on and off through a resistor voltage divider. The two-stage transistor reduces the power consumption of the control signal (the base current only needs to be in the microamp level) while providing sufficient driving capability to ensure stable start-up and shutdown of the partial discharge device. A current-limiting resistor R1 with a resistance of 5Ω to 50Ω is connected in series between the collector of the second transistor and the power supply terminal of the partial discharge detection module. A current-limiting resistor (5Ω~50Ω) is connected in series between the collector of the second transistor and the power supply terminal of the partial discharge device to limit the instantaneous current (such as partial discharge pulse or short circuit fault), prevent the transistor from being damaged by overcurrent, and improve the reliability of the circuit.

[0033] The timing control module features a temperature-compensated crystal oscillator (TCXO) or a Network Time Protocol (NTP) synchronization unit to correct clock drift. This reduces timing error from ±1 minute / day to ±1 second / month for traditional RC circuits, ensuring strict triggering of the detection cycle and preventing missed detections.

[0034] The transient voltage suppression module uses a unidirectional TVS diode with a breakdown voltage of 1.2 to 1.5 times the power supply voltage. The TVS breakdown voltage is limited to 1.2 to 1.5 times the power supply voltage (e.g., a 15V TVS is used for a 12V power supply). It does not operate under normal voltage conditions, but only rapidly conducts during overvoltage events (such as lightning surges) to discharge energy, with a response time of <1ns, protecting downstream circuitry.

[0035] An optocoupler isolation unit is connected between the detection probe and the data processing unit to block common-mode interference. The detection probe is a composite sensor integrating an ultra-high frequency (UHF) antenna and a transient ground voltage (TEV) sensor. Optical isolation is provided between the detection probe (JC) and the data processing unit (CPU). The probe integrates UHF and TEV sensors. The optocoupler blocks ground loop interference and withstands ±5kV common-mode voltage. The composite sensor simultaneously captures internal discharge (UHF) and surface discharge (TEV), improving the defect detection rate from 75% to 95%.

[0036] The data processing unit supports over-the-air (OTA) firmware upgrades and integrates with external IoT platforms via standardized communication protocols. It also supports remote algorithm updates, as those skilled in the art should know, such as AI diagnostic models, to adapt to new sensors; and seamlessly connects to cloud platforms to achieve centralized data management and intelligent early warning.

[0037] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. An interference-free partial discharge measuring device, characterized by: The system includes a power supply module for providing DC power, a transient voltage suppression module for suppressing transient overvoltages on the power line, an LC filter network for filtering high-frequency noise, and a partial discharge detection module. The transient voltage suppression module is connected in parallel between the positive output terminal of the power supply module and ground. The LC filter network consists of an inductor and a multi-stage filter capacitor bank connected in parallel. One end of the inductor is connected to the output terminal of the transient voltage suppression module, and the other end is connected to the positive terminal of the multi-stage filter capacitor bank. The partial discharge detection module consists of a detection probe, a data processing unit, and a wireless communication module connected in sequence. The negative terminal of the multi-stage filter capacitor bank is connected to the input terminal of the detection probe.

2. The interference-free partial discharge measuring device according to claim 1, characterized in that: The transient voltage suppression module uses a unidirectional TVS diode, whose breakdown voltage is 1.2 to 1.5 times the power supply voltage.

3. The interference-free partial discharge measuring device according to claim 2, characterized in that: The multi-stage filter capacitor bank includes a first capacitor, a second capacitor, and a third capacitor. The first capacitor is a tantalum capacitor with low equivalent series resistance and a capacitance of 10μF to 100μF. The second capacitor is a ceramic capacitor with a capacitance of 0.01μF to 1μF. The third capacitor is an electrolytic capacitor with a capacitance of 100μF to 1000μF.

4. The interference-free partial discharge measuring device according to claim 3, characterized in that: The inductor has an inductance of 10μH to 100μH and a rated current greater than 500mA. Together with the multi-stage filter capacitor bank, it forms a low-pass filter with a cutoff frequency of less than 1MHz.

5. The interference-free partial discharge measuring device according to claim 4, characterized in that: A timing control module for triggering partial discharge detection at a preset cycle is connected between the multi-stage filter capacitor bank and the detection probe.

6. The anti-interference partial discharge measuring device according to claim 5, characterized in that: A switching circuit is connected between the timing control module and the detection probe. The switching circuit consists of a first transistor, a second resistor R2, and a second transistor. The output terminal of the timing control module is connected to the base of the first transistor. The collector of the first transistor is connected to the base of the second transistor through the second resistor. The collector of the second transistor is connected to the power supply terminal of the partial discharge detection module.

7. The interference-free partial discharge measuring device according to claim 6, characterized in that A current-limiting resistor with a resistance of 5Ω to 50Ω is connected in series between the collector of the second transistor and the power supply terminal of the partial discharge detection module.

8. The interference-free partial discharge measuring device according to claim 7, characterized in that: The timing control module has a temperature-compensated crystal oscillator or a network time protocol synchronization unit for correcting clock drift.

9. The interference-free partial discharge measuring device according to claim 8, characterized in that: An optically coupled isolation unit for blocking common-mode interference is connected between the detection probe and the data processing unit, and the detection probe is a composite sensor integrating an ultra-high frequency antenna and a transient ground voltage sensor.

10. The interference-free partial discharge measuring device according to claim 9, characterized in that: The data processing unit supports over-the-air firmware upgrades and integrates with external IoT platforms through standardized communication protocols.

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