중간 주파수 유도 가열 장치 can be started but the working status is wrong. How to troubleshoot and deal with it?

(1) Trouble phenomenon The equipment can start without load but the DC voltage does not reach the rated value, and the DC smoothing reactor has an impulsive sound and is accompanied by jitter.

Analyze and deal with turning off the inverter control power supply, connecting a dummy load to the output of the rectifier bridge, and observing the output waveform of the rectifier bridge with an oscilloscope. It can be seen that the cause of the lack of phase in the output waveform of the rectifier bridge may be: the flow trigger pulse is lost; The amplitude of the trigger pulse is not enough and the width is too narrow, resulting in insufficient trigger power, which causes the thyristor to be switched on and off at all times; the pulse timing of the double-pulse trigger circuit is incorrect or the complementary pulse is missing;

(2) Trouble phenomenon The equipment can be started normally and smoothly, and when the power rises to a certain value, overvoltage or overcurrent protection is provided.

The analysis and processing is divided into two steps to find the cause of the fault: first run the equipment with no load and observe whether the voltage can be raised to the rated value; if the voltage cannot be raised to the rated value and the overcurrent protection is close to a certain value of the voltage for many times, this may be a compensation capacitor Or the withstand voltage of the thyristor is not enough, but it is not ruled out that it is caused by a certain part of the circuit. If the voltage can rise to the rated value, the device can be transferred to heavy load operation and observe whether the current value can reach the rated value; It cannot be raised to the rated value, and the overcurrent protection is close to a certain value of the current for many times. This may be a large current interference. Pay special attention to the interference of the electromagnetic field of the medium frequency and large current on the control part and the signal line.