An improved zero-voltage transition inverter for induction motor drive application

In this paper the diode bridge-type ZVT (zero-voltage transition) inverter is proposed. It consists of one auxiliary switch, three resonant inductors and six blocking diodes. So, the advantage of the proposed topology is the reduction of the auxiliary switch. The topology of the proposed ZVT inverter is analyzed with a description of the control conditions based on the load current. Therefore, in this paper two control algorithms are discussed. A variable resonant pattern control algorithm using load current feedback, and a resonant period control algorithm using resonant inductor current feedback, is proposed in order to achieve the ZVT switching condition in full control range and the reducing current spike main switches caused by a reverse recovery problem.