What faults are likely to occur during normal operation of intermediate frequency induction heating equipment and how should they be handled?
(1) Failure phenomenon The equipment is operating normally, but multiple KP thyristors and fast-acting fuses are burned out during normal overcurrent protection action.
In order to release the energy of the smoothing reactor to the power grid during the analysis of overcurrent protection, the rectifier bridge is changed from the rectified state to the inverted state. At this time, if α = 150 °, it may cause the active inverter to overthrow and burn down multiple thyristors and Fast-acting, switching tripped, and accompanied by a huge current short-circuit explosion sound, which will produce a large current and electromagnetic force impact on the transformer, which will damage the transformer in severe cases.
(2) Failure phenomenon The equipment is operating normally but the bypass reactor is burnt out.
The main reasons for the analysis and processing of the bypass reactor caused by the heat and burnout are: the bypass reactor itself is of poor quality; the inverter circuit has asymmetrical operation, and the main cause of the asymmetrical operation of the inverter circuit comes from the signal loop.