To downsize a cooling device for an electric power converter of a hybrid vehicle.
The cooling device comprises a common refrigerant supply passage 80 for supplying a refrigerant to an electric power converter 100 including inverters 21, 31 and a step-up converter 11; each of cooling flow passages 53a, 53b, 63a, 63b, 73a, 73b for cooling each of conversion modules, respectively, by means of refrigerants supplied from the passage 80; each of current detection sensors 28, 29, 38, 39 for detecting each of input/output currents in/from inverters 21, 31, respectively; flow rate regulating valves 55, 65, 75; control unit 90 for controlling opening degrees of the valves 55, 65, 75; and a refrigerant flow rate distribution means for varying the opening degrees of the valves 55, 65, 75 according to a ratio of a magnitude of each current detected by means of each of sensors 28, 29, 38, 39, and varying distribution ratios of the refrigerant flow rates from the common passage 80 to each of flow passages 53a, 53b, 63a, 63b, 73a, 73b.
YOSHINAGA FUMITAKA
YAMAZAKI JOJI
Jun Ishida