Fault analysis of reactor of intermediate frequency furnace

Jun 20, 2022

During the operation of intermediate frequency furnace, the reactor fault is difficult to judge and handle. Generally speaking, the faults prone to occur in the reactor mainly include the following:

1. the inductance of the reactor is changed, and the air gap and coil turns of the reactor of the intermediate frequency furnace are adjusted at will, which affects the filter work of the reactor, and can make the output DC current intermittent, resulting in unstable inversion of the inverter bridge, failure to burn the inverter thyristor, and arbitrarily reduce the air gap of the reactor and coil turns. When the inverter bridge is directly short circuited, the ability of the reactor to block the rise of current will be reduced. Burning the thyristor and changing the inductance of the reactor at will will will also affect the starting performance of the equipment;

2. the reactor coil of intermediate frequency furnace is loose. If the reactor coil is loose, when the electromagnetic force makes the coil shake when the equipment is working, the sudden change of inductance is easy to cause inverter failure during light load starting and low current operation;

3. the reactor coil of intermediate frequency furnace is poorly insulated. Short circuit to ground or turn to turn short circuit, spark discharge causes inductance of reactor, sudden jump and strong electromagnetic interference cause unstable operation of intermediate frequency furnace and frequent abnormal sound, overcurrent burns thyristor, resulting in poor insulation of coil insulation layer and short circuit. The reasons are: poor cooling and high temperature lead to poor insulation of insulation layer, spark and carbonization; The reactor coil is loose, and the insulation layer is damaged due to relative motion friction between the coil insulation layer and the coil insulation layer, and between the coil insulation layer and the iron core; When the reactor coil scale is treated, the acid is infiltrated into the coil, which corrodes the copper pipe and generates copper salt to damage the insulation layer.