pradhan.rachit
Full Member level 3
Dear experts,
I'm working on a firing angle controller to trigger Semikron's SKCH40/12 Semi-controlled rectifier. Attached is the firing scheme used to trigger the module. The pulse transformer used is a Rp4503 type pulse transformer.
1. At first, the firing scheme was such that a 500 us pulse was generated at the firing angle. This works with resistive loads, but as soon as an LC filter is connected for filtration, the SCR fails to turn on properly between 100 degress and 80 degrees and causes severe voltage fluctuation. To solve this, a dummy load was placed before the LC filter to satisfy the latching current requirement, but the SCRs still fail to turn on.
2. The firing scheme was changed by subjecting the gate to a continuous pulse train of 4kHz @ 50% duty cycle. The AC RMS current taken by the gate is 200mA which is higher than the gate requirement of SKCH40/12, but the problem is persistent.
Could someone point out a way to solve this problem? Thank you.
I'm working on a firing angle controller to trigger Semikron's SKCH40/12 Semi-controlled rectifier. Attached is the firing scheme used to trigger the module. The pulse transformer used is a Rp4503 type pulse transformer.
1. At first, the firing scheme was such that a 500 us pulse was generated at the firing angle. This works with resistive loads, but as soon as an LC filter is connected for filtration, the SCR fails to turn on properly between 100 degress and 80 degrees and causes severe voltage fluctuation. To solve this, a dummy load was placed before the LC filter to satisfy the latching current requirement, but the SCRs still fail to turn on.
2. The firing scheme was changed by subjecting the gate to a continuous pulse train of 4kHz @ 50% duty cycle. The AC RMS current taken by the gate is 200mA which is higher than the gate requirement of SKCH40/12, but the problem is persistent.
Could someone point out a way to solve this problem? Thank you.