Reference phase input module and phase synchronization device for partial discharge detection

Abstract

This invention discloses a reference phase input module and a phase synchronization device for partial discharge detection, belonging to the field of partial discharge detection technology. The reference phase input module for partial discharge detection of this invention, by setting up a mains voltage synchronization circuit, a voltage transformer synchronization circuit, a leakage current synchronization circuit, a bus current synchronization circuit, and an electromagnetic field signal synchronization circuit, can synchronize reference phase information for various types of power equipment and different components. It is highly effective and widely applicable, with a scientific and reasonable solution, thus accurately acquiring the reference phase signal. Furthermore, this invention allows for flexible selection of synchronization circuits for different power equipment and components, making it applicable to complex test sites and effectively reducing the impact of various interference signals on partial discharge phase acquisition, avoiding phase signal acquisition failure, and thus improving the accuracy of partial discharge detection results.

Description

Technical Field

[0001] This invention relates to a reference phase input module and a phase synchronization device for partial discharge detection, belonging to the field of partial discharge detection technology. Background Technology

[0002] High-voltage power equipment plays a vital role in the complex processes and tasks of power generation, transmission, and transformation. Insulation condition is a key indicator of the lifespan of this equipment. It is susceptible to partial discharge under the stress of a high-voltage electromagnetic field. By detecting these partial discharge phenomena, we can analyze and infer the insulation condition of this equipment.

[0003] Furthermore, Chinese Patent (CN104569745A) discloses a partial discharge charged detection device and method. The partial discharge charged detection device includes: a high-frequency sensor, an ultra-high-frequency sensor, and an ultrasonic sensor, all used to detect partial discharge signals from electrical equipment; and an oscilloscope, connected to the high-frequency sensor, ultra-high-frequency sensor, and ultrasonic sensor, used to process the partial discharge signals and obtain and display the phase distribution spectrum of the partial discharge signals.

[0004] The above-mentioned scheme obtains the partial discharge signal of power equipment through high-frequency sensors, ultra-high-frequency sensors and ultrasonic sensors. However, for different types of power equipment and different components of the same power equipment, the effectiveness of the above-mentioned detection sensors is low and the scope of application is limited. They cannot be applied to various power equipment and various components, which in turn affects the accurate acquisition of the reference phase signal.

[0005] Furthermore, the field testing environment is complex, with various interference signals affecting the detection of partial discharge. Moreover, the field interference is uncertain, and the operating frequency band of the aforementioned sensors is limited. This can easily lead to the failure of the phase signal acquisition method of the aforementioned sensors, making it impossible to accurately acquire the reference phase signal, which will affect the accuracy of the partial discharge detection results. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a reference phase input module for partial discharge detection. This module is designed to synchronize reference phase information for various types of power equipment and different components by setting up a mains voltage synchronization circuit, a voltage transformer synchronization circuit, a leakage current synchronization circuit, a bus current synchronization circuit, and an electromagnetic field signal synchronization circuit. The module is highly effective, widely applicable, and scientifically and rationally designed, thereby accurately acquiring reference phase signals.

[0007] The second objective of this invention is to provide a phase synchronization device for partial discharge detection that, by setting up a power management module, a reference phase input module, a signal output module, a wireless transceiver module, a processor CPU, and a human-machine interaction module, can synchronize reference phase information for various types of power equipment and different components, with high effectiveness and wide applicability, and a scientific and reasonable solution, thereby accurately acquiring reference phase signals.

[0008] The third objective of this invention is to provide a phase synchronization device for partial discharge detection that employs multiple circuits to acquire a reference phase signal, synchronizes the signal through a processor CPU and a human-machine interface module, outputs an adjustable voltage using a signal output module, is adaptable to various partial discharge detection instruments, and simultaneously outputs the frequency and zero-point phase information of the reference phase signal using a wireless transceiver module. This effectively solves the problem of inconvenient cable connection when the on-site reference signal is far from the partial discharge test location. The device is simple in structure, practical, and easy to manufacture.

[0009] The fourth objective of this invention is to provide a reference phase input module and a phase synchronization device for partial discharge detection, which allows for flexible selection of synchronization circuits for different power equipment and components, is applicable to complex test sites, effectively reduces the influence of various interference signals on partial discharge phase acquisition, avoids phase signal acquisition failure, and thus accurately acquires reference phase signals, thereby improving the accuracy of partial discharge detection results.

[0010] To achieve one of the above objectives, the first technical solution of the present invention is as follows:

[0011] A reference phase input module for partial discharge detection.

[0012] This includes mains voltage synchronization circuit, voltage transformer synchronization circuit, leakage current synchronization circuit, bus current synchronization circuit, and electromagnetic field signal synchronization circuit;

[0013] The mains voltage synchronization circuit is equipped with an optocoupler to obtain a reference phase signal from the mains circuit;

[0014] The voltage transformer synchronization circuit is equipped with an operational amplifier and a filter to obtain a reference phase signal from the secondary side of the voltage transformer.

[0015] The leakage current synchronization circuit is equipped with a multi-stage operational amplifier unit to obtain a reference phase signal from the leakage current on the grounding wire.

[0016] The bus current synchronization circuit is equipped with a coil to obtain a reference phase signal from the bus current;

[0017] The electromagnetic field signal synchronization circuit is equipped with an electric field sensing element, which is used to obtain a reference phase signal by sensing the spatial electromagnetic field signal.

[0018] Through continuous exploration and experimentation, this invention, by setting up a mains voltage synchronization circuit, a voltage transformer synchronization circuit, a leakage current synchronization circuit, a bus current synchronization circuit, and an electromagnetic field signal synchronization circuit, can synchronize the reference phase information of various types of power equipment and different components. It is highly effective and has a wide range of applications. The solution is scientific and reasonable, and thus can accurately obtain the reference phase signal.

[0019] Furthermore, the present invention allows for flexible selection of synchronization circuits for different power equipment and components, making it applicable to complex test sites. It can also effectively reduce the impact of various interference signals on partial discharge phase acquisition, avoid phase signal acquisition failure, and thus accurately acquire reference phase signals, thereby improving the accuracy of partial discharge detection results.

[0020] As a preferred technical measure:

[0021] The optocoupler is electrically connected in sequence to diode D6 and current limiting unit 1;

[0022] Diode D6 is used to protect the optocoupler from damage caused by reverse voltage.

[0023] The first current limiting unit has a group of resistors connected in parallel to limit the current in the circuit.

[0024] After current limiting, the signal is transmitted through optocoupler isolation and outputs a zero-crossing square wave signal of AC mains power.

[0025] The frequency and phase information of AC mains power are obtained by using a zero-crossing square wave signal, and its phase is synchronized with the sinusoidal voltage signal of AC mains power.

[0026] As a preferred technical measure:

[0027] The voltage transformer synchronization circuit also includes a current limiting unit II, a current transformer T1, and an impedance unit;

[0028] The second current limiting unit is equipped with parallel resistor groups to limit the input current, obtain a current signal, and transmit it to the current transformer T1.

[0029] Current transformer T1 is used to output a 1:1 current signal;

[0030] The impedance unit is equipped with an impedance resistor R14, which is used to convert the current signal into a voltage signal;

[0031] The operational amplifier is operational amplifier U3.3, which is used to amplify the voltage signal to obtain the phase synchronization signal FQ2;

[0032] Filters include high-pass filters and low-pass filters;

[0033] The high-pass filter is equipped with capacitor C4 and resistor R15 to filter out some low-frequency interference signals.

[0034] The low-pass filter is equipped with capacitor C5 and resistor R16 to filter out some high-frequency interference signals.

[0035] The input voltage is current-limited by a group of parallel resistors and converted into a current signal, which is then transmitted to the secondary side of the current transformer T1 to output a 1:1 current signal.

[0036] The current signal is converted into a voltage signal after flowing through the impedance resistor R14;

[0037] The voltage signal is filtered by capacitor C4 and resistor R15 to remove some low-frequency interference signals, and by capacitor C5 and resistor R16 to remove some high-frequency interference signals, resulting in a filtered signal of 40Hz to 70Hz.

[0038] The filtered signal is amplified by operational amplifier U3.3 to output phase synchronization signal FQ2.

[0039] As a preferred technical measure:

[0040] Based on the weak leakage current signal, the multi-stage operational amplifier unit includes at least operational amplifier U3.1 and operational amplifier U3.2.

[0041] The leakage current is amplified by two stages of operational amplifier circuits, U3.1 and U3.2, and outputs the frequency and zero-point phase information of the power grid, FQ1.

[0042] As a preferred technical measure:

[0043] The coil is a Rogowski coil, which outputs the change in the bus current and converts it into a current signal through an integrator RC.

[0044] To achieve one of the above objectives, the second technical solution of the present invention is as follows:

[0045] A reference phase synchronization device for partial discharge detection includes a power management module, a reference phase input module for partial discharge detection as described above, a signal output module, a wireless transceiver module, a processor CPU, and a human-machine interaction module.

[0046] The power management module converts the input power and transmits it to the processor CPU and the human-machine interaction module for powering the processor CPU and the human-machine interaction module;

[0047] The reference phase input module acquires the reference phase signal and transmits it to the processor CPU and the human-computer interaction module;

[0048] The processor CPU and human-machine interaction module receive the reference phase signal, output voltage, and transmit wireless data;

[0049] The signal output module dynamically adjusts the output voltage;

[0050] The wireless transceiver module outputs the frequency and zero-point phase information of the reference phase signal.

[0051] Through continuous exploration and experimentation, this invention, by setting up a power management module, a reference phase input module, a signal output module, a wireless transceiver module, a processor CPU, and a human-machine interaction module, can synchronize reference phase information for various types of power equipment and different components. It is highly effective and widely applicable, and the solution is scientific and reasonable, thus enabling accurate acquisition of reference phase signals.

[0052] Furthermore, the present invention allows for flexible selection of synchronization circuits for the reference phase input module for different power equipment and components, making the invention applicable to complex test sites and effectively reducing the impact of various interference signals on partial discharge phase acquisition, avoiding phase signal acquisition failure, thereby accurately acquiring the reference phase signal and improving the accuracy of partial discharge detection results.

[0053] Furthermore, this invention employs multiple circuits to acquire the reference phase signal and synchronizes the signal through a processor CPU and a human-machine interaction module. It uses a signal output module to output an adjustable voltage, which can adapt to various partial discharge detection instruments. At the same time, it uses a wireless transceiver module to output the frequency and zero-point phase information of the reference phase signal, effectively solving the problem that the distance between the field reference signal and the partial discharge test position is too far to be convenient to use a cable connection. The structure is simple, practical, and easy to manufacture.

[0054] As a preferred technical measure:

[0055] The signal output module uses a boost chip U15 to achieve adjustable voltage boosting, which can be used to output different voltages to match different partial discharge test instruments.

[0056] As a preferred technical measure:

[0057] The signal output module includes an inverter U11, a transistor U9, a transistor U10, and a resistor R49;

[0058] Inverter U11 generates a drive signal with a phase difference of 180 degrees, which drives transistors U9 and U10 to output optocouplers and generate a square wave signal with adjustable voltage.

[0059] As a preferred technical measure:

[0060] The wireless transceiver module includes a transmitting unit and a receiving unit;

[0061] The transmitting unit sends a frame of zero-point phase reference phase signal to the receiving unit;

[0062] After receiving the reference phase signal, the receiving unit reconstructs the reference phase signal based on its frequency and phase information.

[0063] As a preferred technical measure:

[0064] The processor CPU and human-machine interaction module include a multi-channel analog unit, a pulse width modulation (PWM) unit, and an SPI communication bus unit;

[0065] The multiplexed analog unit is a multiplexed analog comparator used to input the reference phase signal;

[0066] The pulse width modulation (PWM) unit is used to control the output voltage.

[0067] The communication bus unit (SPI) controls wireless data transmission and LCD liquid crystal display.

[0068] Compared with the prior art, the present invention has the following beneficial effects:

[0069] Through continuous exploration and experimentation, this invention, by setting up a mains voltage synchronization circuit, a voltage transformer synchronization circuit, a leakage current synchronization circuit, a bus current synchronization circuit, and an electromagnetic field signal synchronization circuit, can synchronize the reference phase information of various types of power equipment and different components. It is highly effective and has a wide range of applications. The solution is scientific and reasonable, and thus can accurately obtain the reference phase signal.

[0070] Through continuous exploration and experimentation, this invention, by setting up a power management module, a reference phase input module, a signal output module, a wireless transceiver module, a processor CPU, and a human-machine interaction module, can synchronize reference phase information for various types of power equipment and different components. It is highly effective and widely applicable, and the solution is scientific and reasonable, thus enabling accurate acquisition of reference phase signals.

[0071] Furthermore, the present invention allows for flexible selection of synchronization circuits for different power equipment and components, making it applicable to complex test sites. It can also effectively reduce the impact of various interference signals on partial discharge phase acquisition, avoid phase signal acquisition failure, and thus accurately acquire reference phase signals, thereby improving the accuracy of partial discharge detection results.

[0072] Furthermore, this invention employs multiple circuits to acquire the reference phase signal and synchronizes the signal through a processor CPU and a human-machine interaction module. It uses a signal output module to output an adjustable voltage, which can adapt to various partial discharge detection instruments. At the same time, it uses a wireless transceiver module to output the frequency and zero-point phase information of the reference phase signal, effectively solving the problem that the distance between the field reference signal and the partial discharge test position is too far to be convenient to use a cable connection. The structure is simple, practical, and easy to manufacture. Attached Figure Description

[0073] Figure 1 This is a schematic diagram of a reference phase synchronization device of the present invention;

[0074] Figure 2 This is a schematic diagram of a circuit structure for the power management module of the present invention;

[0075] Figure 3 This is a schematic diagram of a circuit structure for the reference phase input module of the present invention, which obtains power from 220V AC mains.

[0076] Figure 4 This is a schematic diagram of a circuit structure obtained from the secondary side of a voltage transformer by the reference phase input module of the present invention;

[0077] Figure 5 This is a schematic diagram of a circuit structure for obtaining the reference phase input module from the leakage current of the ground wire according to the present invention;

[0078] Figure 6 This is a schematic diagram of the first circuit structure of the signal output module of the present invention;

[0079] Figure 7 This is a schematic diagram of the second circuit structure of the signal output module of the present invention;

[0080] Figure 8 This is a schematic diagram of a circuit structure for the wireless transceiver module of the present invention;

[0081] Figure 9 This is a schematic diagram of the first circuit structure of the processor CPU and human-computer interaction module of the present invention;

[0082] Figure 10 This is a schematic diagram of the second circuit structure of the processor CPU and human-computer interaction module of the present invention.

[0083] Explanation of reference numerals in the attached figures:

[0084] The module includes: 1. Power management module; 2. Reference phase input module; 3. Signal output module; 4. Wireless transceiver module; 5. Processor CPU and human-machine interaction module. Detailed Implementation

[0085] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0086] Conversely, this invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of the invention as defined in the claims. Furthermore, to provide a better understanding of the invention, certain specific details are described in detail below. However, those skilled in the art will fully understand the invention even without these detailed descriptions.

[0087] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention.

[0088] A specific embodiment of the reference phase input module for partial discharge detection of the present invention:

[0089] A reference phase input module for partial discharge detection includes a mains voltage synchronization circuit, a voltage transformer synchronization circuit, a leakage current synchronization circuit, a bus current synchronization circuit, and an electromagnetic field signal synchronization circuit.

[0090] The mains voltage synchronization circuit is equipped with an optocoupler to obtain a reference phase signal from the mains circuit;

[0091] The voltage transformer synchronization circuit is equipped with an operational amplifier and a filter to obtain a reference phase signal from the secondary side of the voltage transformer.

[0092] The leakage current synchronization circuit is equipped with a multi-stage operational amplifier unit to obtain a reference phase signal from the leakage current on the grounding wire.

[0093] The bus current synchronization circuit is equipped with a coil to obtain a reference phase signal from the bus current;

[0094] The electromagnetic field signal synchronization circuit is equipped with an electric field sensing element, which is used to obtain a reference phase signal by sensing the spatial electromagnetic field signal.

[0095] like Figure 1 As shown, a specific embodiment of the reference phase synchronization device for partial discharge detection of the present invention is as follows:

[0096] A reference phase synchronization device for partial discharge detection includes a power management module 1, a phase reference input module 2, a signal output module 3, a wireless transceiver module 4, a processor CPU, and a human-machine interaction module 5.

[0097] The power management module 1 converts the input power and transmits it to the processor CPU and the human-machine interaction module 5 for powering the processor CPU and the human-machine interaction module.

[0098] Phase reference input module 2 acquires the reference phase signal and transmits it to the processor CPU and human-computer interaction module 5.

[0099] The processor CPU and human-machine interaction module 5 receive the reference phase signal, output voltage, and transmit wireless data.

[0100] Signal output module 3 dynamically adjusts the output voltage.

[0101] The wireless transceiver module 4 outputs the frequency and zero-point phase information of the synchronization signal.

[0102] This invention can acquire reference phase signals from multiple channels, synchronize the signals through a processor CPU and a human-machine interaction module, and adjust the output voltage to adapt to various partial discharge detection instruments, thus solving the problem that it is inconvenient to use cables to connect the on-site reference signal and the partial discharge test position when they are far apart.

[0103] A first specific embodiment of the power management module of the present invention:

[0104] The power management module receives 220V power, converts it to 5V, charges the 3.7V lithium battery, converts the lithium battery voltage to 3.3V, and finally outputs 1.5V.

[0105] like Figure 2 As shown, this is a second specific embodiment of the power management module circuit of the present invention:

[0106] The CN6 port receives AC220V power. F1 is a fuse for overcurrent protection, and VR1 is a varistor for overvoltage protection to prevent input overvoltage from damaging downstream components. The AC220V power is converted to 5V by the M1 module (AC-DC conversion module). U1 is a lithium battery charging chip that charges the 3.7V lithium battery. U2 is a voltage regulator chip that regulates the battery voltage to 3.3V. Similarly, U5 is also a voltage regulator chip that generates 1.5V for use by other modules.

[0107] A specific embodiment of the reference phase input module of the present invention:

[0108] The reference phase input module includes a mains voltage synchronization circuit, a voltage transformer synchronization circuit, a leakage current synchronization circuit, a Rogowski coil bus current synchronization circuit, and an electromagnetic field signal synchronization circuit. It is used to obtain the AC220V reference phase, the voltage transformer secondary side reference phase, the grounding wire leakage current reference phase, the Rogowski coil bus current reference phase, and the induced spatial electromagnetic field signal reference phase.

[0109] During on-site testing, a suitable method should be selected based on the site conditions. For example, when testing for partial discharge of a cable, we can choose to use a Rogowski coil to obtain the synchronization signal on the cable.

[0110] A first specific embodiment of the mains voltage synchronization circuit of the present invention:

[0111] The mains voltage synchronization circuit obtains a reference phase signal from the 22V mains power supply, and includes the following:

[0112] A 220V power supply is input from the live wire and neutral wire ports. After voltage division, current limiting, and rectification, the frequency and phase information are output after optocoupler isolation.

[0113] like Figure 3 As shown, a second specific embodiment of the mains voltage synchronization circuit of the present invention is as follows:

[0114] The mains voltage synchronization circuit obtains a reference phase signal from AC220V mains power, and includes the following:

[0115] A 220V power supply is input from the live wire port ACL and the neutral wire port ACN. Resistors R29-R32 are used for current limiting, and D6 provides protection to prevent the optocoupler U12 from being damaged by reverse voltage. After current limiting, the signal from optocoupler U12 is transmitted through optocoupler isolation and outputs an AC220 zero-crossing square wave signal, i.e., the FQ3 signal. FQ3 obtains the frequency and phase information of the 220V mains power, and its phase is synchronized with the AC220V sinusoidal voltage signal.

[0116] A first specific embodiment of the voltage transformer synchronization circuit of the present invention:

[0117] The voltage transformer synchronization circuit obtains the reference phase signal from the secondary side of the voltage transformer. It includes the following: on the secondary side of the voltage transformer, the input voltage is divided and current-limited to be converted into a current signal and transmitted to the current transformer for induction output, then converted into a voltage signal, and output to the grid frequency and zero-point phase information through an operational amplifier method.

[0118] During the process of acquiring the reference phase signal on the secondary side of the voltage transformer, the input-output current ratio of the current transformer is 1:1, and the maximum current is 2mA.

[0119] like Figure 4 As shown, this is the second specific embodiment of the voltage transformer synchronization circuit of the present invention:

[0120] The voltage transformer synchronization circuit obtains a reference phase signal from the secondary side of the voltage transformer, which includes the following:

[0121] The input voltage at the PT terminal is current-limited by resistors R10 and R13, converted into a current signal, and transmitted to the secondary side of current transformer T1. T1 outputs a 1:1 current signal. This current signal flows through resistor R14 and is converted into a voltage signal. Resistor R14 is then amplified by operational amplifier U3.3, outputting the signal FQ2. Capacitor C4 and resistor R15 form a high-pass filter to filter low-frequency interference, while capacitor C5 and resistor R16 form a low-pass filter to filter high-frequency interference. The purpose is to allow signals from 40Hz to 70Hz to pass through, while filtering out signals from other frequency bands.

[0122] The input-output current ratio of T1 is 1:1, and the maximum current is 2mA.

[0123] A first specific embodiment of the leakage current synchronization circuit of the present invention:

[0124] The leakage current synchronization circuit obtains a reference phase signal from the leakage current on the grounding wire. It includes the following: the signal is amplified by two stages of amplifier circuits from the winding port, and the frequency and zero-point phase information of the power grid are output at the output port.

[0125] like Figure 5 As shown, a second specific embodiment of the leakage current synchronization circuit of the present invention is as follows:

[0126] The leakage current synchronization circuit obtains a reference phase signal from the leakage current on the ground wire, and includes the following:

[0127] Since the leakage current is generally weak, it is amplified from the COIL port through two stages of amplifier circuits, U3.1 and U3.2, and the FQ1 port outputs the frequency and zero-point phase information of the power grid.

[0128] A specific embodiment of the bus current synchronization circuit of the present invention:

[0129] The bus current synchronization circuit obtains a reference phase signal from the bus current, which includes the following:

[0130] A Rogowski coil is used to obtain a reference phase signal from the bus current. The Rogowski coil outputs the change value of the bus current and converts it into a current signal through an integrator RC.

[0131] A specific embodiment of the electromagnetic field signal synchronization circuit of the present invention:

[0132] The electromagnetic field signal synchronization circuit obtains a reference phase signal by sensing spatial electromagnetic field signals, and includes the following:

[0133] Since the on-site testing environment consists of high-voltage live equipment, which radiates electromagnetic field signals, the voltage induced by the electric field induction device is input into the circuit to obtain the reference phase signal.

[0134] like Figure 6 As shown, the first specific embodiment of the signal output module of the present invention is as follows:

[0135] The signal output module 3 uses a U15 boost chip to achieve adjustable voltage boosting, allowing it to match different partial discharge test instruments with varying output voltages, thus providing greater flexibility. Specifically, the required voltage amplitude is input via the LCD display. The CPU and human-machine interface module 5 calculate the corresponding control voltage, i.e., the PWM duty cycle, and set the output HVPWM signal accordingly. Figure 6 The calculation is performed using the circuit diagram and Thevenin's theorem, and the formula is as follows:

[0136]

[0137] in For output voltage, The feedback voltage of chip U15 is fixed at 1.2V. 390K For 10K, The value is 11K, and HPWM is the duty cycle for regulating the voltage, with a range of 0%-100%. The simplified formula is as follows:

[0138]

[0139] That is, when HPWM is 0%, the maximum output voltage is 90.5V, and when HPWM is 71%, the output voltage is 7.5V.

[0140] like Figure 7 As shown, a second specific embodiment of the signal output module of the present invention is as follows:

[0141] The processor CPU and human-machine interface module select the square wave signal that matches the reference input. The CPU's built-in timer module generates the square wave signal and outputs it to the FQ_OUT port. The FQ_OUT port then uses inverter U11 to generate a drive signal with a 180-degree phase difference, which drives Darlington output optocouplers U9 and U10 to produce an adjustable square wave signal. U9 and U10 are preferably TIL127 resistors, with a collector withstand voltage of up to 300V, meeting the ±75V output withstand voltage requirement. Resistor R49 is the output current sampling resistor. The CPU module uses its internal ADC unit to collect the voltage across this resistor in real time. If the voltage exceeds the set value, the HVEN signal is activated to shut down the boost source and the square wave signal output module, preventing damage to the protection device. The overcurrent protection calculation formula is as follows:

[0142]

[0143] Where Vi is the input voltage ADC, I is the output current, resistor R49 is 30K, resistor R50 is 100K, and resistor R51 is 47K. The formula simplifies to:

[0144]

[0145] This device is equipped with overcurrent protection of 10mA, according to the above formula. The range is 0.85V to 1.25V; the processor CPU module determines whether the ADC conversion data is within this range. If it exceeds this range, it will immediately shut down the output and trigger an alarm.

[0146] like Figure 8 As shown, a specific embodiment of the wireless transceiver module of the present invention is as follows:

[0147] The wireless transceiver module 4 includes a transmitting unit and a receiving unit. The transmitting unit transmits a synchronization signal with zero-point phase for each frame, and the receiving unit receives the frequency and phase information to reconstruct this synchronization signal.

[0148] The wireless transceiver module 4 adopts the 2.4G universal wireless frequency band and prioritizes the use of the LORA chip SX1280, which has strong anti-interference capabilities and a long transmission and reception distance, meeting the requirements of the field application environment.

[0149] A first specific embodiment of the processor CPU and human-computer interaction module of the present invention:

[0150] The processor CPU and human-computer interaction module include a multi-channel analog unit, a pulse width modulation (PWM) unit, and a communication bus unit (SPI). The multi-channel analog unit is used to input a reference phase signal, the PWM unit is used to control the output voltage condition, and the SPI unit controls wireless data transmission and LCD liquid crystal display.

[0151] like Figure 9 and 10 As shown, this is a second specific embodiment of the processor CPU and human-computer interaction module of the present invention:

[0152] The processor CPU and human-machine interaction module 5 include a multi-channel analog unit, a pulse width modulation (PWM) unit, and a communication bus unit (SPI). The multi-channel analog unit is a multi-channel analog comparator built into the ARM processor, used to input the reference phase signal. The PWM unit is used to control the output voltage condition. The SPI unit controls the wireless data transmission and LCD display. Preferably, an HC32F030 processor and a 128x64 dot matrix LCD display are used.

[0153] 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 it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A reference phase input module for partial discharge detection, characterized in that, This includes mains voltage synchronization circuit, voltage transformer synchronization circuit, leakage current synchronization circuit, bus current synchronization circuit, and electromagnetic field signal synchronization circuit; The mains voltage synchronization circuit is equipped with an optocoupler to obtain a reference phase signal from the mains circuit; The voltage transformer synchronization circuit includes an operational amplifier, a filter, a current limiting unit II, a current transformer T1, and an impedance unit, which is used to obtain a reference phase signal from the secondary side of the voltage transformer. The second current limiting unit is equipped with parallel resistor groups to limit the input current, obtain a current signal, and transmit it to the current transformer T1. Current transformer T1 is used to output a 1:1 current signal; The impedance unit is equipped with an impedance resistor R14, which is used to convert the current signal into a voltage signal; The operational amplifier is operational amplifier U3.3, which is used to amplify the voltage signal to obtain the phase synchronization signal FQ2; Filters include high-pass filters and low-pass filters; The high-pass filter is equipped with capacitor C4 and resistor R15 to filter out some low-frequency interference signals. The low-pass filter is equipped with capacitor C5 and resistor R16 to filter out some high-frequency interference signals. The input voltage is current-limited by a group of parallel resistors and converted into a current signal, which is then transmitted to the secondary side of the current transformer T1 to output a 1:1 current signal. The current signal is converted into a voltage signal after flowing through the impedance resistor R14; The voltage signal is filtered by capacitor C4 and resistor R15 to remove some low-frequency interference signals, and by capacitor C5 and resistor R16 to remove some high-frequency interference signals, resulting in a filtered signal of 40Hz to 70Hz. The filtered signal is amplified by operational amplifier U3.3 to output phase synchronization signal FQ2; The leakage current synchronization circuit is equipped with a multi-stage operational amplifier unit to obtain a reference phase signal from the leakage current on the grounding wire. The bus current synchronization circuit is equipped with a coil to obtain a reference phase signal from the bus current; The electromagnetic field signal synchronization circuit is equipped with an electric field sensing element, which is used to obtain a reference phase signal by sensing the spatial electromagnetic field signal.

2. The reference phase input module for partial discharge detection as described in claim 1, characterized in that, The optocoupler is electrically connected in sequence to diode D6 and current limiting unit 1; Diode D6 is used to protect the optocoupler from damage caused by reverse voltage. The first current limiting unit is equipped with parallel resistor groups for limiting the current in the circuit; After current limiting, the signal is transmitted through optocoupler isolation and outputs a zero-crossing square wave signal of AC mains power. The frequency and phase information of AC mains power are obtained by using a zero-crossing square wave signal, and its phase is synchronized with the sinusoidal voltage signal of AC mains power.

3. The reference phase input module for partial discharge detection as described in claim 1, characterized in that, Based on the weak leakage current signal, the multi-stage operational amplifier unit includes at least operational amplifier U3.1 and operational amplifier U3.

2. The leakage current is amplified by two stages of operational amplifier circuits, U3.1 and U3.2, and outputs the frequency and zero-point phase information of the power grid, FQ1.

4. A reference phase input module for partial discharge detection as described in any one of claims 1-3, characterized in that, The coil is a Rogowski coil, which outputs the change in the bus current and converts it into a current signal through an integrator RC.

5. A reference phase synchronization device for partial discharge detection, characterized in that, It includes a power management module, a reference phase input module for partial discharge detection as described in any one of claims 1-4, a signal output module, a wireless transceiver module, a processor CPU, and a human-machine interaction module; The power management module converts the input power and transmits it to the processor CPU and the human-machine interaction module for powering the processor CPU and the human-machine interaction module; The reference phase input module acquires the reference phase signal and transmits it to the processor CPU and the human-computer interaction module; The processor CPU and human-machine interaction module receive the reference phase signal, output voltage, and transmit wireless data; The signal output module dynamically adjusts the output voltage; The wireless transceiver module outputs the frequency and zero-point phase information of the reference phase signal.

6. A reference phase synchronization device for partial discharge detection as described in claim 5, characterized in that, The signal output module uses a boost chip U15 to achieve adjustable voltage boosting, which can be used to output different voltages to match different partial discharge test instruments.

7. A reference phase synchronization device for partial discharge detection as described in claim 5, characterized in that, The signal output module includes an inverter U11, a transistor U9, a transistor U10, and a resistor R49; Inverter U11 generates a drive signal with a phase difference of 180 degrees, which drives transistors U9 and U10 to output optocouplers and generate a square wave signal with adjustable voltage.

8. A reference phase synchronization device for partial discharge detection as described in claim 5, characterized in that, The wireless transceiver module includes a transmitting unit and a receiving unit; The transmitting unit sends a frame of zero-point phase reference phase signal to the receiving unit; After receiving the reference phase signal, the receiving unit reconstructs the reference phase signal based on its frequency and phase information.

9. A reference phase synchronization device for partial discharge detection as described in any one of claims 5-8, characterized in that, The processor CPU and human-machine interaction module include a multi-channel analog unit, a pulse width modulation (PWM) unit, and an SPI communication bus unit; The multiplexed analog unit is a multiplexed analog comparator used to input the reference phase signal; The pulse width modulation (PWM) unit is used to control the output voltage. The communication bus unit (SPI) controls wireless data transmission and LCD liquid crystal display.

Images