With the development of the power system, the capacity of operating equipment is increasing, such as thermal power generation units, which have a single unit capacity of over 1000MW, and hydroelectric power generation units, which have a maximum single unit capacity of 800MW. If traditional testing equipment (i.e. frequency test transformers) is used for the AC power frequency withstand voltage test of these devices, due to the large capacity required for the test, the test transformers and voltage regulators are very bulky, and it is difficult to solve the problem of large capacity test power supply on site, making on-site testing extremely inconvenient. The power frequency resonance device has great advantages in terms of test power capacity, equipment weight, test waveform, and investment. This device is mainly designed and manufactured for the AC withstand voltage test of hydraulic generators with a single unit capacity of 250MW and below.
Test operation method for AC voltage withstand test device (power frequency induction) of generator:
1. Overcurrent protection setting: Set the low-voltage current relay and high-voltage current relay in the control panel separately, generally set to 1.1 times the test current.
2. Overvoltage protection setting: Set to 1.1 times the voltage during the test.
3.Example: When the test voltage is 45kV, the display should be adjusted to 47kV.
4. Connect the shielding wire of the voltage divider to the two high-voltage terminals on the control console. Note that all ground wires must be securely and reliably connected.
5. Connect the high-voltage currents K1 and K2 on the excitation transformer to the high-voltage current terminals on the control panel
6. Voltage endurance time setting: Set the test time on the time relay to the desired test time.
7. Connect the test wiring according to the instructions and check for errors before closing the circuit.
8. Close the circuit breaker on the control panel. If the voltage regulator is not in the zero position, it will automatically return to zero. The test can only be conducted after the regulator returns to zero.
9. Generally, before the main power supply is not connected, adjust the reactor core clearance, and observe whether the lifting and clearance limit protection functions are normal. In addition, it is possible to adjust the boost and buck appropriately, and observe whether the button and low-voltage voltage meter are working properly.
Wuhan UHV specializes in producing series resonance (also known as variable frequency series resonance withstand voltage device) and has been engaged in the electrical measurement industry for many years. Its products have first-class quality and welcome customers to come and purchase.
