How to protect IGBT in Power supply

1 use current transformer to detect over-current for protection

The current transformer is connected in series with IGBT to detect the current flowing through the IGBT collector. When over-current occurs, the control actuator disconnects the IGBT input.

2.VCE (SAT) of IGBT detects over-current for protection

Because VCE (SAT) = icrce (SAT), when IC increases, VCE (SAT) also increases. If the gate voltage is high and VCE is high, there will be over-current. At this time, the gate outputs high level, and the over-current signal is output. The actuator is controlled to disconnect the input of IGBT to protect IGBT.

3. Detect the load current for protection

If the load is short circuited or the load current increases, the collector current of the former IGBT may also increase, resulting in IGBT damage. After the load (or the next stage circuit of IGBT) detects the abnormality, the control actuator cuts off the input of IGBT.