High-voltage transformer series resonance withstand voltage test system and automatic tuning method

Abstract

The invention relates to a high-voltage transformer series resonance withstand voltage test system and an automatic tuning method, and relates to the technical field of high-voltage electrical equipment testing, and the system comprises a control module, a signal generator, a resonance circuit, a data acquisition module and a safety protection unit. The method comprises the following steps: initializing system parameters; automatically searching and locking an optimal resonant frequency point; executing a withstand voltage test at the resonance point and monitoring data; and automatically analyzing data and judging performance. According to the invention, through full-closed-loop automatic control, rapid and accurate locking of the resonant frequency and intellectualization of the test process are realized, and the problems of low efficiency, poor precision and insufficient safety of a traditional method are effectively solved. The device has the outstanding advantages of high adaptive capacity, reliable test result and safety and convenience in operation, and is particularly suitable for high-efficiency and accurate standardized test on the insulating properties of various high-voltage transformers in an electric power system.

Description

Technical Field

[0001] This application relates to the field of high-voltage electrical equipment testing technology, and in particular to a high-voltage transformer series resonant withstand voltage test system and automatic tuning method. Background Technology

[0002] High-voltage transformers are key equipment in power systems. Their insulation performance and electrical safety directly affect the stable operation of the power grid. In order to verify the insulation strength of high-voltage transformers under rated voltage or overvoltage conditions, power frequency withstand voltage tests are required.

[0003] Currently, traditional withstand voltage testing methods mostly use a fixed-frequency test power supply, adjusting the output voltage to meet the test requirements. However, this method has the following drawbacks:

[0004] Inflexible frequency adjustment: It is inconvenient to automatically adapt the optimal resonant frequency according to different transformer models, resulting in low test efficiency;

[0005] Limited test accuracy: Inaccurate resonant point may cause the test voltage to fail to meet the standard requirements, affecting the reliability of the test results;

[0006] Poor operational safety: Manual intervention is required during the test, and operators face the risk of electric shock from high voltage.

[0007] Poor adaptability: Transformers of different capacities and voltage levels require reconfiguration of test parameters, resulting in weak system versatility.

[0008] Therefore, there is an urgent need for a high-voltage transformer withstand voltage test system and method that can automatically adjust, is highly adaptable, and has high safety. Summary of the Invention

[0009] The purpose of this application is to provide a high-voltage transformer series resonant withstand voltage test system and automatic tuning method to overcome the aforementioned deficiencies of the prior art. This system and method can achieve fully automatic resonant point search and locking, significantly improving test efficiency and accuracy, while also enhancing operational safety through remote monitoring.

[0010] Firstly, the high-voltage transformer series resonant withstand voltage test system provided in this application adopts the following technical solution, including:

[0011] The control module is used to initialize system parameters, analyze test results, and control the entire test process. The system parameters include at least the test voltage level and frequency range.

[0012] A signal generator, connected to the control module, is used to generate an adjustable frequency power signal according to the instructions of the control module.

[0013] The resonant circuit, connected to the signal generator and the high-voltage transformer under test, includes inductor and capacitor elements and is used to form a series resonant circuit with the high-voltage transformer to generate resonance at a specific frequency.

[0014] The data acquisition module, connected to the control module and the resonant circuit, is used to acquire electrical response data of the high-voltage transformer during the test.

[0015] The safety protection unit is connected to the control module and various electrical components of the system, and is used to provide overvoltage, overcurrent and short-circuit protection during the test.

[0016] By adopting the above technical solutions, a complete and automated high-voltage testing system is constructed, realizing full-process automated control from parameter setting, resonant excitation, data acquisition to safety monitoring, fundamentally overcoming the problems of reliance on manual labor and low efficiency in traditional methods.

[0017] Preferably, the control module includes a high-performance microprocessor for executing an intelligent matching algorithm, which is configured to dynamically adjust the output frequency range of the signal generator and the test voltage level set by the control module according to the rated parameters of the high-voltage transformer under test.

[0018] By adopting the above technical solution, the system possesses adaptive capabilities, enabling intelligent optimization of the initial configuration for different transformer models. This significantly reduces the workload of manually setting parameters and the risks caused by improper parameter settings, thereby improving the efficiency and versatility of test preparation.

[0019] Preferably, the signal generator has a built-in precision frequency conversion circuit, and the output frequency can be continuously adjusted within the range of 20Hz to 300Hz. It can also automatically scan and search for frequencies in steps of no more than 0.1Hz to determine the optimal frequency point corresponding to the circuit resonance state.

[0020] By adopting the above technical solution, a precise and automatic search for the resonant frequency is achieved, ensuring that the system can quickly and accurately lock the optimal resonant point, laying a solid foundation for applying accurate test voltages, thereby significantly improving the accuracy and reliability of the test.

[0021] Preferably, the data acquisition module is equipped with a high-speed analog-to-digital converter (ADC) with a sampling rate of not less than 1MHz, for high-precision capture of the voltage and current transient changes of the high-voltage transformer.

[0022] By adopting the above technical solution, subtle and transient changes in electrical characteristics (such as partial discharge signals) during the test can be captured, providing high-quality data assurance for subsequent accurate analysis of the transformer's insulation performance and avoiding misjudgment or omission due to insufficient data sampling rate.

[0023] Preferably, the system further includes a remote monitoring unit, which integrates a wireless communication module for sending system status information, collected real-time data and alarm signals to a remote control center, and receiving control commands from the remote control center.

[0024] By adopting the above technical solution, physical isolation between testing personnel and the high-voltage testing site is achieved. Operators can complete all operations and monitoring from a safe control center, greatly reducing the direct personal safety risks posed by the high-voltage environment.

[0025] Preferably, the wireless communication module adopts a 4G / 5G network or a local area network communication method to realize remote data monitoring, parameter setting, start and stop control functions, and can send system alarm signals to the control center in real time, including abnormal information such as overvoltage, overcurrent and short circuit.

[0026] By adopting the above technical solutions, the timely issuance of control commands and the real-time uploading of on-site status (especially fault alarm information) are ensured, making the remote monitoring function more real-time, stable and comprehensive.

[0027] Preferably, the intelligent matching algorithm automatically sets the following parameters according to preset matching rules:

[0028] For transformers with a rated voltage of 60kV, the frequency range is automatically set to 20Hz–300Hz, and the test voltage is 60kV.

[0029] For transformers with a rated voltage of 110kV, the frequency range is automatically set to 40Hz–300Hz, and the test voltage is 70kV.

[0030] Its matching rules can be dynamically updated to optimize testing efficiency and security.

[0031] By adopting the above technical solutions, testing experience is solidified into specific and executable rules, enabling the system to automatically execute standardized and optimized testing processes, ensuring the scientific nature and consistency of the testing plan; and its dynamic update capability allows the system to continuously learn and optimize, adapting to new testing standards and transformer models.

[0032] Secondly, this application provides an automatic tuning method for a series resonant withstand voltage test of a high-voltage transformer. Based on the aforementioned system, it employs the following technical solution, including the following steps:

[0033] Step S1: Initialize system parameters, set the test voltage level and frequency search range;

[0034] Step S2: Automatically search for and lock the optimal resonant frequency point. Adjust the output frequency of the signal generator within the frequency search range until the frequency point that makes the series resonant circuit reach the optimal resonant state is found.

[0035] Step S3: At the optimal resonant frequency point, perform a withstand voltage test, and continuously monitor and record the electrical response data of the high-voltage transformer through the data acquisition module;

[0036] Step S4: After the test is completed, the control module automatically analyzes the recorded test data to determine whether the electrical performance of the high-voltage transformer meets the safety standards.

[0037] By adopting the above technical solution, the tedious manual tuning and judgment work is transformed into automated steps, ensuring that the entire pressure test process is efficient, standardized, and repeatable, and minimizing errors and delays introduced by human operation.

[0038] Preferably, in step S2, the automatic search and locking of the optimal resonant frequency point specifically includes: the control module identifies the frequency point where the current of the resonant circuit is at its maximum or the impedance is at its minimum through the current or voltage signal fed back by the data acquisition module, and locks it as the optimal resonant frequency point.

[0039] By adopting the above technical solution, a clear and reliable physical criterion for locking the resonant point is provided. Furthermore, by utilizing the characteristic that the loop current is at its maximum (or the impedance is at its minimum) at resonance, the identification process of the resonant point is made objective and accurate, avoiding the arbitrariness of subjective judgment.

[0040] Preferably, before step S1, an intelligent matching step is also included: the control module reads the nameplate or input rated parameters of the high-voltage transformer under test, and automatically sets the initial test voltage level and frequency search range corresponding to the rated parameters based on the intelligent matching algorithm.

[0041] By adopting the above technical solution, intelligent preprocessing is introduced. Users only need to connect the transformer or input basic information, and the system can automatically complete the complex initial configuration, reducing the operating threshold and dependence on the experience of professional personnel.

[0042] Preferably, the execution of steps S3 and S4 is remotely controlled and monitored by a remote monitoring unit integrated in the system. The operator issues control commands through the remote control center and receives status information and alarm signals from the system.

[0043] By adopting the above technical solution, the high-voltage test execution and result analysis stages are also included in the scope of remote operation, realizing full remote operation from start to finish, enhancing the safety of the test process, and providing great convenience for testing in complex or dangerous environments.

[0044] In summary, this application includes at least one of the following beneficial technical effects:

[0045] 1. This application achieves full automation of the high-voltage transformer withstand voltage test from parameter setting, resonance point search, test execution to result analysis through a closed-loop control system consisting of a control module, a signal generator, and a data acquisition module. This significantly improves testing efficiency, solves the problem of low efficiency caused by the reliance on manual operation in traditional methods, and further eliminates the random errors and subjective judgment biases introduced by human operation to the greatest extent through intelligent program control, ensuring the consistency and reliability of the test process and results.

[0046] 2. This application adopts an intelligent matching algorithm and a precise automatic frequency scanning technology, which has strong adaptive capabilities. The system can automatically initialize the optimal test conditions according to the rated parameters of different transformers and quickly and accurately lock the best resonance point. This overcomes the inherent defects of traditional fixed frequency methods, which are difficult to adapt to multiple samples and have limited test accuracy. This allows the system to ensure that the test is carried out in the optimal resonance state when facing high-voltage transformers of various models in the power system, thereby obtaining real and reliable insulation performance evaluation results.

[0047] 3. This application constructs a hardware and software integrated safety protection system by integrating a safety protection unit with multiple protection mechanisms and a remote monitoring unit, and achieves physical isolation between test personnel and the high-voltage test site; operators can remotely complete all operations and monitoring from a safe control center, fundamentally eliminating the personal safety risks that may be caused by direct operation under high-voltage conditions; at the same time, the remote monitoring function improves the system's operational convenience and application flexibility, making it particularly suitable for complex or high-risk test scenarios such as substation sites and field operations. Attached Figure Description

[0048] Figure 1 This is the overall architecture diagram of the high-voltage transformer series resonant withstand voltage test system of this application;

[0049] Figure 2 This is the overall flowchart of the automatic tuning method for the series resonant withstand voltage test of the high-voltage transformer in this application;

[0050] Explanation of reference numerals in the attached diagram: Control module-101, Signal generator-102, Resonant circuit-103, Data acquisition module-105, Safety protection unit-106, Remote monitoring unit-107. Detailed Implementation

[0051] The following is in conjunction with the appendix Figure 1 -Appendix Figure 2 This application will be described in further detail below.

[0052] This application provides a high-voltage transformer series resonant withstand voltage test system, see reference. Figure 1 It includes a control module 101, a signal generator 102, a resonant circuit 103, a data acquisition module 105, a safety protection unit 106, and a remote monitoring unit 107; the modules work together to realize the automated withstand voltage test of the high-voltage transformer 104 under test.

[0053] in:

[0054] Control Module 101: As the command center of the system, its core adopts a high-performance 32-bit ARM microprocessor (such as the STM32H7 series) or an equivalent DSP (digital signal processor). The processor runs an embedded real-time operating system and is responsible for executing the system's main control program, intelligent matching algorithm, and data analysis logic. Its peripheral circuits include SDRAM (for storing temporary data), Flash (for storing program code and preset rules), multiple UART / SPI / I2C interfaces (for communicating with other modules), and Ethernet or USB interfaces (for system debugging and initial configuration).

[0055] Signal generator 102: This module receives digital frequency commands from control module 101 (transmitted via SPI bus). Its core is a precision frequency conversion circuit, which consists of a direct digital frequency synthesizer (DDS) chip (such as AD9959) and a high-precision power amplifier circuit. The DDS chip can generate high-purity sine waves with a frequency resolution of up to 0.01Hz, which are then amplified by the power amplifier circuit to the required voltage and power levels. In this embodiment, signal generator 102 can continuously output within a frequency range of 20Hz to 300Hz, and can perform frequency scanning in steps of 0.1Hz or smaller according to the instructions of control module 101, thereby achieving precise automatic frequency seeking.

[0056] Resonant circuit 103: This circuit is used to generate high voltage. Its inductor is an adjustable reactor, and its capacitor includes a fixed compensation capacitor and the equivalent capacitance of the high voltage transformer 104 under test. During the test, the inductance of the reactor is adjusted so that it can resonate in series with the total capacitance within the target frequency range. When the frequency output by the signal generator 102 is equal to the inherent resonant frequency of the circuit, the circuit resonates, generating a high voltage at the two ends of the high voltage transformer 104 under test that is much higher than the excitation voltage.

[0057] Data acquisition module 105 includes:

[0058] High-voltage probes and Rogowski coils (or current transformers) are used to accurately measure the voltage and loop current on the high-voltage side of a transformer, respectively.

[0059] The signal conditioning circuit filters and amplifies the sensor signal to make it suitable for the input range of the ADC.

[0060] A high-speed analog-to-digital converter (ADC) using a chip with a sampling rate of at least 1MHz and a resolution of 16 bits (such as AD7606) ensures that transient pulses or partial discharge signals that may occur during withstand voltage tests can be captured, providing raw data for accurate analysis; the acquired data is transmitted to the control module 101 via a high-speed parallel bus or Ethernet.

[0061] Safety protection unit 106: Composed of hardware comparator, fast fuse and software logic; the hardware circuit monitors key voltage and current signals in real time. Once the set safety threshold is exceeded (such as overvoltage 110% and overcurrent 120%), the hardware comparator will directly trigger the relay within microseconds to cut off the main circuit; at the same time, the software will also continuously monitor these parameters. When an abnormality is detected, it will immediately send a stop command to the signal generator 102 and record the fault information to achieve dual protection.

[0062] Remote monitoring unit 107: This unit integrates a 4G / 5G communication module or an industrial-grade Wi-Fi module. It is connected to the control module 101 via a UART interface and runs a TCP / IP protocol stack. Its function is to establish a reliable data tunnel, encapsulate and upload data such as the system status, real-time waveforms, and alarm information of the control module 101 to the server of the remote control center. At the same time, it receives control commands such as "start test", "set parameters", and "emergency stop" issued by the control center.

[0063] Please see Figure 2 The present invention provides an automatic tuning method for a series resonant withstand voltage test of a high-voltage transformer. The specific implementation process of this method is as follows:

[0064] Step S10: Before the formal test begins, the system can perform an intelligent matching preparatory step: the control module 101 reads the nameplate information of the high-voltage transformer 104 under test or the rated parameters input by the operator through the human-machine interface, and then automatically sets the initial test voltage level and frequency search range corresponding to the rated parameters based on the intelligent matching algorithm stored in its internal memory; for example, for a transformer with a rated voltage of 60kV, the control module 101 automatically sets the frequency range of the signal generator 102 to 20Hz-300Hz and sets the test voltage to 60kV.

[0065] Step S1, initialize system parameters: The control module 101 initializes the test voltage level and frequency search range according to the intelligent matching result or manual setting, and sends the frequency control parameters to the signal generator 102 through the SPI bus.

[0066] Step S2, automatically search and lock the optimal resonant frequency point: The control module 101 instructs the signal generator 102 to scan the output frequency in fine steps (e.g., 0.1Hz) within the set frequency range; at the same time, the control module 101 monitors the loop current signal fed back by the data acquisition module 105 in real time; according to the series resonance principle, when the resonant circuit 103 resonates, its impedance is the minimum and the current is the maximum. Therefore, the control module 101 identifies the frequency point where the current of the resonant circuit is the maximum (or equivalent to the minimum impedance) by comparing the current values ​​at different frequencies.

[0067] Once the point is found, the control module 101 immediately locks it as the optimal resonant frequency for this experiment and instructs the signal generator 102 to fix the output at this frequency; the process is fully automated, eliminating errors caused by human judgment.

[0068] Step S3: At the optimal resonant frequency point, a withstand voltage test is performed: the control module 101 commands the signal generator 102 to stably output at the locked optimal resonant frequency point, and gradually increases its output voltage to the preset test voltage level; within the specified withstand voltage time (e.g., 60 seconds), the data acquisition module 105 continuously monitors and records the electrical response data of the high-voltage transformer 104, and all data is transmitted and stored in real time to the control module 101 via a high-speed parallel bus or Ethernet; during this period, the hardware and software of the safety protection unit 106 are under real-time monitoring.

[0069] Step S4, Test Termination and Performance Analysis: After the withstand voltage time is reached, the system automatically and smoothly reduces the voltage and stops; the control module 101 automatically analyzes the test data recorded by the data acquisition module 105, and judges whether the electrical performance of the high-voltage transformer 104 meets the safety standards by checking whether the waveform is smooth and whether there are any sudden changes or distortions, and automatically generates a conclusive report.

[0070] Example: A full-process application scenario integrating remote monitoring:

[0071] Based on the above method and system, this embodiment introduces a remote monitoring unit 107 to conduct annual preventive tests on the high-voltage transformers of multiple substations under a certain power company.

[0072] Implementation method:

[0073] 1. On-site technicians only need to connect the test system to the high-voltage transformer 104 under test and power it on.

[0074] 2. Experts located in the central laboratory can access the remote monitoring unit 107 on-site via a remote connection.

[0075] 3. Experts at the control center remotely drive the control module 101 to execute steps S10 and S1 by issuing instructions through the remote monitoring unit 107.

[0076] 4. When an expert remotely issues a start command, the control module 101 automatically executes steps S2 (frequency search) and S3 (pressure withstand test). Throughout the process, the execution of steps S3 and S4 is remotely monitored and controlled by the remote monitoring unit 107. The expert can see the real-time waveform uploaded by the data acquisition module 105 and the system status reported by the safety protection unit 106.

[0077] 5. If the safety protection unit 106 triggers an alarm during the test, its signal will be packaged by the control module 101 and immediately uploaded to the control center via the remote monitoring unit 107, so that experts can intervene remotely. After the test, the analysis report will be automatically uploaded to the central database.

[0078] Technical effect summary: It realizes full remote control from start to finish. The remote monitoring unit 107 establishes a safe and reliable remote channel, so that operators do not need to approach the high voltage site during the entire process, which greatly enhances the personal safety of the testing process. It is especially suitable for testing tasks in harsh environments or requiring a high degree of coordination.

Claims

1. A high voltage transformer series resonance withstand voltage test system, characterized by, The system comprises: a control module for initializing system parameters, analyzing test results and controlling the entire test process, wherein the system parameters at least include test voltage level and frequency range; a signal generator connected with the control module, for generating adjustable frequency power supply signal according to the instruction of the control module; a resonance circuit connected with the signal generator and the high voltage transformer under test, containing inductance and capacitance elements, for forming a series resonance circuit with the high voltage transformer and generating resonance at a specific frequency; a data acquisition module connected with the control module and the resonance circuit, for collecting electrical response data of the high voltage transformer during the test process; a safety protection unit connected with the control module and each electrical component of the system, for providing overvoltage, overcurrent and short circuit protection during the test process.

2. The high-voltage transformer series resonance withstand voltage test system according to claim 1, characterized in that, The control module comprises a high-performance microprocessor for executing an intelligent matching algorithm, which is configured to dynamically adjust the output frequency range of the signal generator and the test voltage level set by the control module according to the rated parameters of the high voltage transformer under test.

3. The high-voltage transformer series resonance withstand voltage test system and automatic tuning method according to claim 1, characterized in that, The signal generator is built-in with a precision frequency conversion circuit, and the output frequency can be continuously adjustable within the range of 20Hz to 300Hz, and can automatically scan and search for frequency with a step of not more than 0.1Hz to determine the optimal frequency point corresponding to the resonance state of the circuit.

4. The high-voltage transformer series resonance withstand voltage test system according to claim 1, characterized in that, The data acquisition module is equipped with a high-speed analog-to-digital converter with a sampling rate of not less than 1MHz, for capturing the voltage and current transient changes of the high voltage transformer with high precision.

5. The high-voltage transformer series resonance withstand voltage test system according to claim 1, characterized in that, The system further comprises a remote monitoring unit integrated with a wireless communication module, for sending system status information, collected real-time data and alarm signals to the remote control center, and receiving control instructions from the remote control center.

6. The high-voltage transformer series resonance withstand voltage test system according to claim 5, characterized by, The wireless communication module adopts 4G / 5G network or local area network communication mode, realizes remote data monitoring, parameter setting, start and stop control functions, and can send system alarm signals to the control center in real time, including abnormal information of overvoltage, overcurrent and short circuit.

7. A method for automatic tuning of a high voltage transformer series resonance withstand voltage test, using a system according to any one of claims 1 to 6, characterized in that, The method comprises the following steps: Step S1: initializing system parameters, setting test voltage level and frequency search range; Step S2: automatically searching and locking the optimal resonance frequency point, adjusting the output frequency of the signal generator within the frequency search range until the frequency point that makes the series resonance circuit reach the optimal resonance state is found; Step S3: performing withstand voltage test at the optimal resonance frequency point, and continuously monitoring and recording the electrical response data of the high voltage transformer through the data acquisition module; Step S4: after the test is completed, the control module automatically analyzes the recorded test data to determine whether the electrical performance of the high voltage transformer meets the safety standards.

8. The automatic tuning method of a high-voltage transformer series resonance withstand voltage test according to claim 7, characterized in that, In the step S2, the automatic searching and locking of the optimal resonance frequency point specifically includes: the control module identifies the frequency point at which the current of the resonance circuit is maximum or the impedance is minimum through the current or voltage signal feedback by the data acquisition module, and locks it as the optimal resonance frequency point.

9. The automatic tuning method of a high-voltage transformer series resonance withstand voltage test according to claim 7, characterized in that, Before the step S1, an intelligent matching step is further included: the control module reads the nameplate of the high-voltage transformer to be tested or input rated parameters, and automatically sets the initial test voltage level and frequency search range corresponding to the rated parameters based on an intelligent matching algorithm.

10. The automatic tuning method of a high-voltage transformer series resonance withstand voltage test according to claim 7, characterized in that, The execution processes of the steps S3 and S4 are remotely controlled and monitored by a remote monitoring unit integrated in the system, and an operator issues control instructions and receives state information and alarm signals fed back by the system through a remote control center.

Images