Induction melting furnace maintenance fault repair method

Induction melting furnace maintenance 1: The induction melting furnace is operating normally, but burns more KP thyristors and fast melts during normal overcurrent protection. Analysis and processing:

In the event of overcurrent protection, in order to release the energy of the smoothing reactor to the grid, the rectifier bridge is switched from the rectified state to the inverting state. If α>120 degrees, it is possible to cause active inverter subversion and burn more thyristors and Fast-melting, switch tripping, accompanied by a huge current short-circuit explosion sound, causing large current and electromagnetic force impact on the transformer, and severely damage the transformer.

Induction melting furnace maintenance 2:

The induction melting furnace is operating normally, but the induction melting furnace is unstable near a certain point in the high voltage zone, the DC voltmeter is shaking, and the induction melting furnace is accompanied by a squeaking sound. This situation is very likely to cause the inverter bridge to subvert and burn the thyristor.

Analytical processing: This kind of fault is difficult to eliminate, and it often occurs in a high-voltage ignition of a certain part of the induction melting furnace:

(1) The loose copper wire of the connecting copper wire joint causes the fire;

(2) oxidation of the main joint of the circuit breaker causes ignition;

(3) The compensation capacitor wiring pile screw is loose, causing sparking, and the internal resistance of the compensation capacitor is absorbed and ignited;

(4) The insulated part of the water-cooled radiator is too dirty or carbonized to ignite the ground;

(5) The induction coil of the furnace body is fired on the furnace shell/furnace bottom plate, and the induction coils of the furnace body are too close to each other, and the ignition or arcing occurs between the turns. The insulating column of the induction furnace induction coil is fired by high temperature carbonization discharge.

(6) The inside of the thyristor is ignited.