Zero Current Switch

In a Zero Current Switch, the external circuit defines the current in the switch. This current tends to zero, and hence the IGBT does not turn off current, so no tail appears. Another problem that can occur with the IGBT, latching, does not occur in this mode. Even if the IGBT latches at the maximum current, it can turn off later because the current is defined by the external circuit. The carriers that remained in the base of the pnp-transistor can be recovered by a positive current into the base. In a Zero Current Switch, the negative half wave of the resonant current flows through the ant parallel diode. During that time, a negative voltage is applied to the IGBT. Current flows through the body diode of the internal MOSFET into the base of the pnptransistorResonant converter topologies can be used to increase circuit switching speeds, allowing the cost of circuit magnetic to be reduced, while still keeping switching losses to a minimum. Full wave rather than half wave topologies are generally used, as they generate less EMI. Capacitive switching losses when turning on with a high drain-source voltage means that MOSFETs are more suitable for Zero -Voltage than Zero-Current switches, while its poor turn-off characteristics mean that the IGBT is more suited to Zero-Current topologies.