Electric current reversible chopper circuit

摘要

PURPOSE:To reduce snubber loss, by constituting a snubber circuit only with capacitors. CONSTITUTION:A reversible current chopper comprises first and second switching elements, i.e., transistors 18, 19, a current smoothing circuit 14 comprising a smoothing reactor 12 and a capacitor 13, a control section 20 and the like, where power is fed from a power source 9 to a rotary machine 15 in order to operate the rotary machine 15 as a motor. A FET18 comprises a switching element, i.e., a body section 18a, and a parasitic diode 18b, and a FET19 is constituted similarly. The control section 20 outputs first and second control signals 21, 22 and performs ON/OFF control of FET body sections 18a, 19a. The FET's 18, 19 are provided in parallel with snubber capacitors 23, 24 and connected with the current smoothing circuit 14. Since a DC power source 9 is not shortcircuited through circulation diodes 18b, 19b, turn-off loss is reduced.