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CN-122017326-A - Overvoltage testing module for excitation de-excitation zinc oxide valve plate of hydraulic generator

CN122017326ACN 122017326 ACN122017326 ACN 122017326ACN-122017326-A

Abstract

An excitation de-excitation zinc oxide valve plate overvoltage test module of a hydraulic generator relates to a hydraulic generator overvoltage test device and aims to solve the problems that an existing zinc oxide valve plate overvoltage test is complex in operation, poor in flexibility of operation and low in test precision. The invention discloses a zinc oxide resistor, which comprises a zinc oxide resistor, a potentiometer, a current detection unit, a voltage detection unit and a voltage detection unit, wherein one end of the zinc oxide resistor is used as a direct-current high-voltage positive input end, the other end of the zinc oxide resistor is connected with one fixed end of the potentiometer, the other fixed end of the potentiometer is used as a direct-current high-voltage negative input end, the movable end of the potentiometer is used for being connected with one end of a tested excitation de-excitation zinc oxide valve plate, the direct-current high-voltage negative input end is used for being connected with the other end of the tested excitation de-excitation zinc oxide valve plate, the current detection unit is used for detecting the current value of the tested excitation de-excitation zinc oxide valve plate, and the voltage detection unit is used for detecting the voltage value of the tested excitation de-excitation zinc oxide valve plate. The valve plate testing device has the beneficial effects of simplicity and convenience in operation, portability, suitability for testing requirements of valve plates with various specifications, high testing precision and accurate and reliable results.

Inventors

  • WANG JUAN
  • CAO HONGLIANG
  • ZHOU ZHAORUI
  • ZHAO HONGGUANG
  • CHEN HUILONG
  • ZHAO ZHIQIANG
  • LIU YI

Assignees

  • 国网黑龙江省电力有限公司牡丹江水力发电总厂

Dates

Publication Date
20260512
Application Date
20260318

Claims (10)

  1. 1. The overvoltage testing module for the excitation de-excitation zinc oxide valve plate of the hydraulic generator is characterized by comprising a current detecting unit (2), a voltage detecting unit (3) and a direct current voltage dividing circuit; the direct current voltage dividing circuit comprises a zinc oxide resistor (4) and a potentiometer (5); One end of the zinc oxide resistor (4) is used as a direct current high-voltage positive electrode input end, the other end of the zinc oxide resistor (4) is connected with one fixed end of the potentiometer (5), the other fixed end of the potentiometer (5) is used as a direct current high-voltage negative electrode input end, the moving end of the potentiometer (5) is used for being connected with one end of a tested excitation de-excitation zinc oxide valve plate, and the direct current high-voltage negative electrode input end is used for being connected with the other end of the tested excitation de-excitation zinc oxide valve plate; The current detection unit (2) is used for detecting the current value of the detected excitation de-excitation zinc oxide valve plate; the voltage detection unit (3) is used for detecting the voltage value of the detected excitation de-excitation zinc oxide valve plate.
  2. 2. The overvoltage testing module of the excitation de-excitation zinc oxide valve plate of the hydraulic generator according to claim 1, further comprising an insulation resistance tester (1); The direct-current high-voltage anode output end of the insulation resistance tester (1) is connected with one end of the zinc oxide resistor (4), and the direct-current high-voltage cathode output end of the insulation resistance tester (1) is connected with the other fixed end of the potentiometer (5).
  3. 3. The overvoltage testing module for the excitation de-excitation zinc oxide valve plate of the hydraulic generator according to claim 2, wherein the output direct-current voltage gear of the insulation resistance tester (1) is 1000V.
  4. 4. The hydraulic generator excitation de-excitation zinc oxide valve plate overvoltage testing module according to claim 1, wherein the resistance value of the zinc oxide resistor (4) is 500mΩ.
  5. 5. The hydraulic generator excitation de-excitation zinc oxide valve plate overvoltage testing module according to claim 1, wherein the resistance value of the potentiometer (5) is 10mΩ.
  6. 6. The hydraulic generator excitation de-excitation zinc oxide valve plate overvoltage test module according to claim 1, wherein the direct current voltage dividing circuit further comprises a current limiting resistor (6); the current limiting resistor (6) is connected in series between the other fixed end of the potentiometer (5) and the direct-current high-voltage negative electrode input end.
  7. 7. The hydraulic generator excitation de-excitation zinc oxide valve plate overvoltage testing module according to claim 6, wherein the resistance value of the current limiting resistor (6) is 10mΩ.
  8. 8. The overvoltage testing module for the excitation de-excitation zinc oxide valve plate of the hydraulic generator according to claim 1 is characterized in that the voltage detection unit (3) is connected in parallel between a moving end of a potentiometer (5) and a direct-current high-voltage negative electrode input end, and the voltage detection unit (3) is a high-voltage voltmeter, and the measuring range of the high-voltage voltmeter is 0-1000V.
  9. 9. The overvoltage testing module for the excitation de-excitation zinc oxide valve plate of the hydraulic generator according to claim 1, wherein the current detection unit (2) is connected in series with the moving end of the potentiometer (5), the current detection unit (2) is a milliamp meter, and the measuring range of the milliamp meter is 0-10mA.
  10. 10. The overvoltage testing module for the excitation de-excitation zinc oxide valve plate of the hydraulic generator according to claim 1, wherein the current detection unit (2), the voltage detection unit (3) and the direct current voltage division circuit are all packaged in an insulating shell, and the adjusting knob of the potentiometer (5), the display interface of the voltage detection unit (3) and the display interface of the current detection unit (2) are all arranged on a panel of the insulating shell.

Description

Overvoltage testing module for excitation de-excitation zinc oxide valve plate of hydraulic generator Technical Field The invention relates to an overvoltage testing device for a hydraulic generator. Background The hydro-generator is used as core equipment of the power system, and the safe and stable operation of the hydro-generator is directly related to the reliability of the power grid. The generator rotor exciting winding is a key component of the generator set and is subjected to various overvoltage infringements in the operation process, when the inside or the outlet end of the generator set breaks down and is stopped normally, transient overvoltage is caused at the two ends of the rotor winding, when the generator set is greatly disturbed in operation, a static exciting synchronous generator possibly generates forward or reverse overvoltage on the rotor exciting winding, a typical de-excitation and overvoltage protection device mainly comprises a de-excitation switch, a zinc oxide valve plate, a silicon controlled rectifier trigger, a silicon controlled rectifier element, a diode, a current transformer and the like, an overvoltage action value (usually taking voltage corresponding to 1mA direct current as a reference value) of the zinc oxide valve plate is a core parameter for measuring the protection performance of the zinc oxide valve plate, the action threshold and the protection level of the protection device are directly determined, and the field test technology for the overvoltage action value of the excitation de-excitation zinc oxide valve plate of the water turbine generator still has the following technical defects that firstly, the existing test equipment is large in size and heavy in general, the field test equipment needs to be carried to the field of the generator exciting system, the test equipment needs to be operated by professional technicians, the operation is long in the field, the test preparation time is required, and the operation of the field test equipment is poor in the field operation of the complex space and the field test equipment is convenient. In addition, the existing test method generally adopts test voltage with fixed gears, is difficult to adapt to the test requirements of zinc oxide valve plates with different types and different voltage levels, and has the defects of insufficient test flexibility due to the need of changing test instruments or measuring ranges with different specifications for different valve plates with action voltages ranging from hundreds of volts to thousands of volts. Finally, the existing test equipment has higher requirements on the test environment, is difficult to ensure the test precision and stability under the hydropower station site environment with higher humidity and electromagnetic interference, and meanwhile, the existing test equipment needs an external power supply, so that the power supply is inconvenient to acquire under a specific overhaul scene. In summary, the prior art lacks a special device which is simple and convenient to operate, convenient to carry and suitable for field test of the overvoltage action value of the excitation de-excitation zinc oxide valve plate of the hydraulic generator. Disclosure of Invention The invention aims to solve the problems of complex operation, poor operation flexibility and low test precision of the traditional zinc oxide valve plate overvoltage test, and provides an excitation de-excitation zinc oxide valve plate overvoltage test module of a hydraulic generator. The invention relates to a hydraulic generator excitation de-excitation zinc oxide valve plate overvoltage test module which comprises a current detection unit, a voltage detection unit and a direct current voltage division circuit; The direct current voltage dividing circuit comprises a zinc oxide resistor and a potentiometer; The other fixed end of the potentiometer is used as a direct current high-voltage negative electrode input end, the moving end of the potentiometer is used for connecting one end of a measured excitation de-excitation zinc oxide valve plate, and the direct current high-voltage negative electrode input end is used for connecting the other end of the measured excitation de-excitation zinc oxide valve plate; The current detection unit is used for detecting the current value of the detected excitation de-excitation zinc oxide valve plate; the voltage detection unit is used for detecting the voltage value of the detected excitation de-excitation zinc oxide valve plate. Further, the device also comprises an insulation resistance tester; The output end of the direct-current high-voltage anode of the insulation resistance tester is connected with one end of a zinc oxide resistor, and the output end of the direct-current high-voltage cathode of the insulation resistance tester is connected with the other fixed end of the potentiometer. Further, the output direct-current voltage gear of the insulation resistance t