Exciting transformer partial discharge test system

Abstract

The utility model discloses a partial discharge test system for an exciting transformer, which belongs to the technical field of electric power tests and comprises a frequency tripling transformer, an isolation transformer, an exciting transformer, a partial discharge measurement module, a measurement loop and a control circuit. The frequency tripling transformer outputs alternating voltage to the isolation transformer; the isolation transformer isolates the alternating voltage, provides a resistive load and an inductive load, converts the waveform of the alternating voltage into a standard sinusoidal waveform, and outputs the standard sinusoidal waveform to the excitation transformer; the partial discharge measurement module is connected with a high-voltage side winding of the exciting transformer, sets test parameters of the exciting transformer and detects the partial discharge quantity of the exciting transformer; the measurement loop monitors the alternating voltage and the corresponding current in real time; the control circuit is connected with the measuring loop and the frequency tripling transformer, receives the alternating voltage monitored by the measuring loop and the corresponding current, and then adjusts the alternating voltage output by the frequency tripling transformer in combination with preset parameters. According to the utility model, the test efficiency and accuracy can be improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of electric power testing, and in particular relates to a partial discharge testing system for an excitation transformer. Background Art

[0002] In the context of the rapid development of the modern power industry, excitation transformers play a vital role in thermal power generation units. As a core component of the power system, the insulation performance of the excitation transformer affects the reliability and stability of the power system. Partial discharge (PD) is a phenomenon that occurs during the insulation degradation process of equipment such as transformers. It typically occurs within or on the surface of the insulating material, causing localized breakdown of the dielectric due to excessive local electric field strength. Although this discharge phenomenon may not be easily detected at first, if not controlled and treated, it will gradually worsen and eventually lead to insulation failure, affecting the safe operation of the entire power system.

[0003] To ensure the long-term stability of the power system, it is particularly important to perform partial discharge detection on the excitation transformer. Partial discharge detection technology can promptly detect potential defects in the insulation system of the excitation transformer. By analyzing the characteristics and patterns of the discharge, the insulation condition can be evaluated, thereby preventing the occurrence of faults. However, traditional partial discharge test equipment for excitation transformers generally uses partial discharge test equipment for conventional large transformers, which has many problems in practical applications. First, these devices are usually large in size and heavy in weight, making transportation and handling inconvenient, especially in space-constrained field environments. In particular, in some remote or complex terrain power stations, the transportation and deployment of large equipment has become a major challenge. Second, the operation of traditional equipment is complex and requires professional personnel for operation and maintenance, which not only increases the cost of the test, but also prolongs the test time. In addition, the reliability of the test results when using large-capacity equipment as a substitute for testing remains to be investigated.

[0004] Therefore, traditional excitation transformer partial discharge test equipment has significant limitations in practical applications. These issues restrict the efficiency and effectiveness of partial discharge tests and pose a potential threat to the safe operation of power systems. There is an urgent need for an excitation transformer partial discharge test system to address these issues and improve test efficiency and accuracy. Utility Model Content

[0005] The purpose of the utility model is to provide an excitation transformer partial discharge test system to improve the efficiency and accuracy of the current excitation transformer partial discharge test.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] In a first aspect, a partial discharge test system for an excitation transformer includes: a tripler transformer, an isolation transformer, an excitation transformer, a partial discharge measurement module, a measurement circuit, and a control circuit;

[0008] The secondary side of the triple frequency transformer is connected to the isolation transformer for outputting the AC voltage to the isolation transformer;

[0009] The isolation transformer is connected to the excitation transformer, and is used to isolate the alternating voltage and provide resistive load and inductive load, and then convert the waveform of the alternating voltage into a standard sine waveform and output it to the excitation transformer;

[0010] The partial discharge measurement module is connected to the high-voltage side winding of the excitation transformer and is used to set the test parameters of the excitation transformer and detect the partial discharge amount of the excitation transformer;

[0011] The measuring circuit is connected to the excitation transformer and is used for real-time monitoring of the alternating voltage and its corresponding current;

[0012] The control circuit is connected to the measurement circuit and the triple frequency transformer, and is used to receive the alternating voltage and its corresponding current monitored by the measurement circuit, and then adjust the alternating voltage output by the triple frequency transformer in combination with preset parameters.

[0013] In some embodiments, the triple frequency transformer is composed of three single-phase transformers, and each single-phase transformer has a rated capacity of 50 kVA.

[0014] In some embodiments, the rated voltage of each of the single-phase transformers is 380V / 20kV.

[0015] In some embodiments, the partial discharge measurement module includes: a coupling capacitor, an impedance box, and a partial discharge tester;

[0016] The coupling capacitor and the impedance box are connected to the high-voltage side winding of the excitation transformer, and the partial discharge tester is connected to the impedance box.

[0017] In some embodiments, the coupling capacitor has a rated voltage of 30 kV and a capacitance of 0.1 uF.

[0018] In some embodiments, the impedance value of the impedance box is 100Ω.

[0019] In some embodiments, the sensitivity of the partial discharge meter is 0.1 pC.

[0020] In some embodiments, the measurement circuit includes a voltage transformer and a current transformer, and the voltage transformer and the current transformer are respectively connected to the excitation transformer.

[0021] In some embodiments, the control circuit employs a microprocessor.

[0022] In some embodiments, the isolation transformer is rated at 50 kVA.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The utility model provides an excitation transformer partial discharge test system, comprising: a triple frequency transformer, an isolation transformer, an excitation transformer, a partial discharge measurement module, a measurement circuit and a control circuit; the secondary side of the triple frequency transformer is connected to the isolation transformer, and an alternating voltage is output to the isolation transformer; the isolation transformer is connected to the excitation transformer, isolates the alternating voltage and provides a resistive load and an inductive load, and then converts the waveform of the alternating voltage into a standard sinusoidal waveform and outputs it to the excitation transformer; the partial discharge measurement module is connected to the high-voltage side winding of the excitation transformer, sets the test parameters of the excitation transformer, and detects the partial discharge amount of the excitation transformer; the measurement circuit is connected to the excitation transformer, and monitors the alternating voltage and its corresponding current in real time; the control circuit is connected to the measurement circuit and the triple frequency transformer, and after receiving the alternating voltage and its corresponding current monitored by the measurement circuit, adjusts the alternating voltage output by the triple frequency transformer in combination with preset parameters. The utility model uses a triple frequency transformer and an isolation transformer to output a stable alternating voltage, which helps to reduce waveform distortion and improve the accuracy and reliability of the test; the partial discharge measurement module can accurately set the test parameters and monitor the partial discharge amount of the excitation transformer in real time, which helps to evaluate the insulation performance of the excitation transformer and discover potential fault points; in addition, the utility model monitors the alternating voltage and current in real time through the measurement loop and feeds the data back to the control circuit. The control circuit then adjusts the alternating voltage output by the triple frequency transformer in combination with preset parameters to achieve closed-loop control, thereby improving the test efficiency while ensuring the stability and safety of the test process.

[0025] Furthermore, the utility model adopts a triple frequency transformer as the power supply, which significantly improves the portability and practicality of the test system. The triple frequency transformer generates a 150Hz frequency output through the combination of three single-phase transformers, which not only simplifies the equipment structure, but also improves the flexibility and adaptability of the test.

[0026] Furthermore, the partial discharge measurement module of the utility model includes a coupling capacitor, an impedance box and a partial discharge tester, and the measurement circuit includes a voltage transformer and a current transformer, which can achieve precise control of the test process, including real-time adjustment of frequency, voltage and current. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic structural diagram of a partial discharge test system for an excitation transformer provided in Example 1;

[0028] In the figure, 1. Triple frequency transformer; 2. Isolation transformer; 3. Voltage transformer; 4. Current transformer; 5. Excitation transformer; 6. Coupling capacitor; 7. Impedance box; 8. Partial discharge tester; 9. AC 380V; 10. Control circuit; 11. Measurement circuit; 12. Partial discharge measurement module. DETAILED DESCRIPTION

[0029] Hereinafter, only certain exemplary embodiments are briefly described, and the described embodiments can be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and description are to be regarded as illustrative rather than restrictive in nature.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of this utility model, "plurality" means two or more, unless otherwise specifically defined.

[0031] In this utility model, unless otherwise specified or limited, the terms "install," "connect," "connected," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. For those skilled in the art, the specific meanings of the above terms in this utility model can be understood according to specific circumstances.

[0032] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0033] Example 1

[0034] like Figure 1 As shown, this embodiment provides an excitation transformer partial discharge test system, including a triple frequency transformer 1, an isolation transformer 2, a control circuit 10, a measurement circuit 11, a partial discharge measurement module 12 and an excitation transformer 5;

[0035] The triple frequency transformer 1 is composed of a single-phase transformer T1, a single-phase transformer T2, and a single-phase transformer T3. Their primary sides are connected in a star configuration and their secondary sides are connected in an open triangle configuration. The rated capacity of each single-phase transformer is 50 kVA and the rated voltage is 380 V / 20 kV.

[0036] The isolation transformer 2 uses a 50 kVA isolation transformer 2, which is used to isolate the alternating voltage output by the triple frequency transformer 1 and provide resistive load and inductive load to ensure that the alternating voltage has a standard sinusoidal waveform.

[0037] The measurement circuit 11 includes a high-precision voltage transformer 3 and a current transformer 4, which are used to monitor the alternating voltage and corresponding current of the triple frequency transformer in real time.

[0038] The control circuit 10 is a microprocessor-based control unit for receiving data from the measurement circuit 11 and adjusting the output of the triple frequency transformer 1 according to preset parameters to ensure the accuracy and safety of the test.

[0039] In addition, the control circuit 10 performs coordinated control based on communication data, interface data, etc., has a human-machine friendly operation interface, and is equipped with a screen display that can display key parameters such as output voltage, current, frequency, and fault information prompts in real time.

[0040] The excitation transformer 5 (tested product) is a three-phase oil-immersed excitation transformer with a rated capacity of 500 kVA. The high-voltage side winding of the excitation transformer is connected to the partial discharge measurement module 12 .

[0041] The partial discharge measurement module 12 includes a coupling capacitor 6, an impedance box 7, and a partial discharge tester 8. The coupling capacitor 6 has a rated voltage of 30 kV and a capacitance of 0.1 μF; the impedance of the impedance box 7 is 100 Ω; and the partial discharge tester 8 has a sensitivity of 0.1 pC. It is used to set the test parameters of the excitation transformer 5 and detect the partial discharge amount of the excitation transformer 5.

[0042] The test steps of the excitation transformer partial discharge test system are as follows:

[0043] Connect the primary side of the triple frequency transformer 1 to a three-phase power supply of 380V AC;

[0044] The output of the triple frequency transformer is adjusted by the control circuit 10 so that a 150 Hz alternating voltage is generated on its secondary side;

[0045] The output voltage of the triple frequency transformer 1 is adjusted to a voltage level suitable for testing the excitation transformer 5 using the isolation transformer 2 .

[0046] Connect the high-voltage side winding of the excitation transformer 5 to the partial discharge measurement module 12 through the coupling capacitor 6 and the impedance box 7;

[0047] Start the partial discharge tester 8 and set appropriate test parameters, such as test voltage, test frequency and test time;

[0048] The triple frequency transformer 1 is started by the control circuit 10, and the test voltage of the excitation transformer 5 is gradually increased, while the output of the partial discharge measurement module 12 is monitored;

[0049] The partial discharge activity detected by the partial discharge tester 8 is recorded, and the insulation state of the excitation transformer 5 is analyzed.

[0050] Analysis of test results:

[0051] If the partial discharge amount detected by the partial discharge tester 8 is lower than the set threshold, it indicates that the insulation performance of the excitation transformer 5 is good; if the partial discharge amount exceeds the threshold, it is necessary to further analyze the location and cause of the partial discharge and take corresponding maintenance or replacement measures.

[0052] In this embodiment, when conducting a partial discharge test on the excitation transformer 5, after ensuring that the input power is normal, the control circuit 10 activates the triple frequency transformer 1. At this point, the triple frequency transformer 1 is powered on and automatically enters standby mode. Subsequently, the measurement function is activated, and the measurement circuit 11 immediately begins real-time monitoring and recording the output voltage and current data of the triple frequency transformer 1, transmitting this data to the control circuit 10. The control circuit 10 analyzes this data in real time, compares it with preset test parameters, and adjusts the output of the triple frequency transformer 1 accordingly to ensure that the test is conducted accurately according to the established parameters. When the output of the triple frequency transformer 1 reaches a preset safety or performance threshold, the voltage is no longer increased. Throughout the test, the control circuit 10 also monitors the operating status of the power supply in real time. If any abnormality is detected, the output power is immediately cut off to protect the equipment and ensure the safety of the test personnel. Simultaneously, the control circuit 10 displays fault information on a display in real time, providing detailed information on the fault type and occurrence time, allowing the operator to quickly identify the problem and take appropriate measures. This process not only improves test efficiency but also ensures test safety and data accuracy.

[0053] This embodiment uses a triple-frequency transformer 1 as the power supply. This innovative design significantly improves the portability and practicality of the system. The triple-frequency transformer 1 generates a 150Hz frequency output through the combination of three single-phase transformers, which not only simplifies the equipment structure but also improves the flexibility and adaptability of the test. The system is particularly suitable for on-site use and can maintain good waveform quality even with low capacity, reducing the risk of resonance with the test object. The design of this system fully considers the ease of operation and safety of the test. The design of the control circuit 10 and the measurement circuit 11 enables precise control of the test process, including real-time adjustment of frequency, voltage, and current. The system is also equipped with a grounding device to ensure the safety of test personnel and equipment. In terms of structural design, this system adopts a modular design for easy transportation and on-site assembly. The system's user-friendly operating interface makes the test process more intuitive and convenient. The excitation transformer partial discharge test system proposed in this embodiment, through technological innovation, overcomes the limitations of traditional equipment in excitation transformer partial discharge testing, improves the efficiency and accuracy of the test, and provides a strong guarantee for the safe operation of the power system.

[0054] Example 2

[0055] This embodiment provides an excitation transformer partial discharge test system, comprising: a triple frequency transformer 1, an isolation transformer 2, an excitation transformer 5, a partial discharge measurement module 12, a measurement circuit 11, and a control circuit 10;

[0056] The secondary side of the triple frequency transformer 1 is connected to the isolation transformer 2, which outputs the alternating voltage to the isolation transformer 2; the isolation transformer 2 is connected to the excitation transformer 5, which isolates the alternating voltage and provides resistive load and inductive load, and then converts the waveform of the alternating voltage into a standard sinusoidal waveform and outputs it to the excitation transformer 5; the partial discharge measurement module 12 is connected to the high-voltage side winding of the excitation transformer 5, sets the test parameters of the excitation transformer 5, and detects the partial discharge amount of the excitation transformer 5; the measurement circuit 11 is connected to the excitation transformer 5, and monitors the alternating voltage and its corresponding current in real time; the control circuit 10 is connected to the measurement circuit 11 and the triple frequency transformer 1, and is used to receive the alternating voltage and its corresponding current monitored by the measurement circuit 11, and then adjust the alternating voltage output by the triple frequency transformer 1 in combination with preset parameters.

[0057] This embodiment uses a triple frequency transformer 1 and an isolation transformer 2 to output a stable alternating voltage, which helps to reduce waveform distortion and improve the accuracy and reliability of the test. The partial discharge measurement module 12 can accurately set test parameters and monitor the partial discharge amount of the excitation transformer 5 in real time, which helps to evaluate the insulation performance of the excitation transformer 5 and discover potential fault points. In addition, the utility model monitors the alternating voltage and current in real time through the measurement loop 11 and feeds the data back to the control circuit 10. The control circuit 10 then adjusts the alternating voltage output by the triple frequency transformer 1 in combination with preset parameters to achieve closed-loop control, thereby improving the test efficiency while ensuring the stability and safety of the test process.

[0058] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the embodiments disclosed above are merely illustrative in all respects and are not exclusive. All modifications within the scope of the present invention or equivalent to the scope of the present invention are included in the present invention.

Claims

1. A partial discharge test system for an excitation transformer, characterized in that: include: A triple frequency transformer (1), an isolation transformer (2), an excitation transformer (5), a partial discharge measurement module (12), a measurement circuit (11), and a control circuit (10); The secondary side of the triple frequency transformer (1) is connected to the isolation transformer (2) for outputting an alternating voltage to the isolation transformer (2); The isolation transformer (2) is connected to the excitation transformer (5) and is used to isolate the alternating voltage and provide a resistive load and an inductive load, and then convert the waveform of the alternating voltage into a standard sinusoidal waveform and output it to the excitation transformer (5); The partial discharge measurement module (12) is connected to the high-voltage side winding of the excitation transformer (5) and is used to set the test parameters of the excitation transformer (5) and detect the partial discharge amount of the excitation transformer (5); The measuring circuit (11) is connected to the excitation transformer (5) and is used to monitor the alternating voltage and its corresponding current in real time; The control circuit (10) is connected to the measurement circuit (11) and the triple frequency transformer (1), and is used to receive the alternating voltage and its corresponding current monitored by the measurement circuit (11), and then adjust the alternating voltage output by the triple frequency transformer (1) in combination with preset parameters.

2. The partial discharge test system for an excitation transformer according to claim 1, characterized in that: The triple frequency transformer (1) is composed of three single-phase transformers, each of which has a rated capacity of 50 kVA.

3. The partial discharge test system for an excitation transformer according to claim 2, characterized in that: The rated voltage of each single-phase transformer is 380V / 20kV.

4. The partial discharge test system for an excitation transformer according to claim 1, characterized in that: The partial discharge measurement module (12) includes: a coupling capacitor (6), an impedance box (7) and a partial discharge tester (8); The coupling capacitor (6) and the impedance box (7) are connected to the high-voltage side winding of the excitation transformer (5), and the partial discharge tester (8) is connected to the impedance box (7).

5. The partial discharge test system for an excitation transformer according to claim 4, characterized in that: The rated voltage of the coupling capacitor (6) is 30 kV and the capacitance value is 0.1 uF.

6. The partial discharge test system for an excitation transformer according to claim 4, characterized in that: The impedance value of the impedance box (7) is 100Ω.

7. The partial discharge test system for an excitation transformer according to claim 1, characterized in that: The sensitivity of the partial discharge tester (8) is 0.1 pC.

8. The excitation transformer partial discharge test system according to claim 1, characterized in that: The measuring circuit (11) includes a voltage transformer (3) and a current transformer (4), and the voltage transformer (3) and the current transformer (4) are respectively connected to the excitation transformer (5).

9. The partial discharge test system for an excitation transformer according to claim 1, characterized in that: The control circuit (10) adopts a microprocessor.

10. The partial discharge test system for an excitation transformer according to claim 1, characterized in that: The rated capacity of the isolation transformer (2) is 50kVA.

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