Patent ID: 8289743
Filing Date: 2012-10-16
Classification: B60L,H02M,Y02T

Abstract:
1. A voltage control device, comprising: a capacitor for supplying electric power to a predetermined load; an inverter connected to the load; an AC-coupling bi-directional DC-DC converter including two voltage source inverters of which direct-current terminals are connected in series to each other so as to have additive polarity and a transformer for AC-coupling alternating-current terminals of the two voltage source inverters and having a predetermined leak inductance, with one of the two voltage source inverters connected in parallel to the capacitor, for outputting direct-current voltage obtained by increasing capacitor voltage of the capacitor to the inverter; and a control unit for generating a command value to output under a load operation by using a direct-current voltage value based on efficiency of the AC-coupling bi-directional DC-DC converter corresponding to the capacitor voltage, wherein when generating the command value of the direct-current voltage under the load operation, the control unit sets the direct-current voltage value as a first supplementary candidate value, while the control unit sets the direct-current voltage value determined so as to correspond to an internal temperature of the AC-coupling bi-directional DC-DC converter as a second supplementary candidate value, and the control unit sets a smaller one of the first and second supplementary candidate values as the command value of the direct-current voltage under the load operation.