Patent ID: 8830701

Claim:
A DC-DC converter, comprising: a transformer; a voltage-source power converter that is provided at a primary side of the transformer; a first voltage detection circuit that detects a first voltage between first input and output terminals of the voltage-source power converter; a current-source power converter that is provided at a secondary side of the transformer; a second voltage detection circuit that detects a second voltage between second input and output terminals of the current-source power converter; a current detection circuit that detects an input-output current between the second input and output terminals of the current-source power converter; and a controller that controls the voltage-source power converter and the current-source power converter to transfer power between the primary side and the secondary side of the transformer, wherein the first input and output terminals of the voltage-source power converter are connected to one of an inverter that drives an electric motor or a storage battery, the second input and output terminals of the current-source power converter are connected to the other of the inverter that drives the electric motor or the storage battery, the controller includes: a first control unit that generates a first control input QQ 1 for the input-output current based on the first voltage, a second control unit that generates a second control input QQ 2 for the input-output current based on the second voltage, and a third control unit that generates a command value based on the first and second control inputs QQ 1 and QQ 2 and the input-output current, the voltage-source power converter and the current-source power converter are controlled based on the command value, and the first control input QQ 1 is in a range: −I 2 ≦QQ 1 ≦I 1 wherein, I 1 is a greatest value of a charge current value for the storage battery, and I 2 is a greatest value of a discharge current for the storage battery.