POWER SUPPLY SYSTEM OF ELECTRICALLY DRIVEN VEHICLE AND CONTROL METHOD THEREOF

摘要

During an external power supply, external charging relays (RL1, RL2) are rendered on, while system main relays (SMR1, SMR2) are rendered off. Therefore, a main battery (10) can be charged by a power from an external power source (400) with no output voltage of the main battery (10) applied to a PCU (20). During the external charging, the power supply voltage (Vs) of an auxiliary machinery system (low voltage system) is basically generated by halting a main DC/DC converter (60) of a large capacity, which is to be used during a vehicle drive, while using a subsidiary DC/DC converter (115) of a small capacity. Only when the power to be consumed by the auxiliary machinery system cannot be sufficiently provided by the output of the subsidiary DC/DC converter (115), an ECU (80) activates the main DC/DC converter (60). Thus, the efficiency of the external charging can be improved, while the ECU (80) and auxiliary machinery load groups (90, 95) can be driven with reliability.