| 摘要 |
PROBLEM TO BE SOLVED: To provide a single-phase or polyphase power converter which has a smaller switching loss when a switch is turned on. SOLUTION: A converter 1 constituted of switches Q1-Q6, diodes D1-D6, and capacitors C1-C6 is connected to an AC power supply AC through reactors L1-L3 for step-up. Between the output DC lines E1 and E2 of the converter 1, a capacitor C0 for soft switching is connected. A soft switching control circuit 3 having a reactor L11 and control switches Q11, Q12, Q13 is installed. The capacitor C0 is shorted for a specified period of time by means of the switches Q1-Q6. The rise and fall of the voltage VC0 of the capacitor C0 is sloped by the control of the control circuit 3. When the voltage of the capacitor C0 becomes nearly zero, a switch of the converter 1 is turned on. |
