Series Resonant Inverter with Bidirectional Switch ECE 442

Series Resonant Inverter with Bidirectional Switch ECE 442 Power Electronics 1

Turn Q 1 ON at t = 0 A “resonant” pulse of current flows, charging C to VC 1, Q 1 turns OFF ECE 442 Power Electronics 2

C charges to VC 1, Q 1 turns OFF ECE 442 Power Electronics 3

C discharges via D 1 and Vs • For t > t 1 – The capacitor acts as a voltage source – Current io reverses, and flows via D 1 to VS ECE 442 Power Electronics 4

“Idealized Version” ECE 442 Power Electronics 5

ECE 442 Power Electronics 6

Half-Bridge Series Resonant Inverter ECE 442 Power Electronics 7

Turn Q 1 ON, Resonant Pulse of current appears. ECE 442 Power Electronics 8

Turn Q 2 ON, Resonant Pulse of current appears in the opposite direction, and goes to zero. ECE 442 Power Electronics 9

Waveform Summary ECE 442 Power Electronics 10

Overlapping and Non-Overlapping modes • Non-Overlapping Mode – Firing of the switching device is delayed until the last current oscillation through the diode is completed ECE 442 Power Electronics 11

Overlapping and Non-Overlapping modes • Overlapping Mode – Firing of the switching device occurs before the last current oscillation through the diode is completed. – This increases the output frequency and the output power ECE 442 Power Electronics 12