When the high-voltage AC asynchronous motor is started directly, the starting current is very large (generally 4 to 7 times the rated current), causing pollution to the power grid and voltage instability. In order to overcome this phenomenon is usually the use of buck or current limiting to start AC asynchronous motor, the commonly used buck method is the motor stator with a reactor or water resistor, the commonly used current limiting method is in the winding motor rotor series frequency sensitive rheostat or water resistor, after starting to cut the reactor, frequency sensitive rheostat or water resistor.
The reactor core is made of high-quality cold-rolled silicon steel sheet, which is divided into uniform sections through multiple air gaps, and is isolated and bonded by epoxy plate to ensure the stable performance and corrosiveness of the equipment during operation, and the noise is also controlled. The coil is wrapped in structure, and the main insulation of the coil is glass fiber impregnated with epoxy resin, which is heated and cured under vacuum and impregnated with high voltage insulating paint, so that the coil has the characteristics of good insulation, high mechanical strength, high current resistance, cold and hot resistance without cracking.
Advantages of high voltage buck or current limiting starting:
1, small starting impact, large torque (frequency sensitive rheostat, water resistance cabinet):
2, small size, light weight, small footprint, simple structure, easy installation:
3, the temperature grade reaches H or F, the starting reactor core temperature is not more than 85K, the coil mixing is not more than 95K;
4, small starting noise;
5, reduce the motor starting temperature, effectively extend the motor life:
6, the starting process is smooth (frequency sensitive rheostat), no impact on mechanical equipment:
7, the grid requirements are not high, will not produce harmonics and affect the grid:
8, good versatility, can be applied to any load condition winding motor soft start (frequency sensitive rheostat), especially suitable for heavy load starting.
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