US 8,478,469 B2Granted

Power source system for electric powered vehicle and control method therefor

AssigneeToyota Jidosha Kabushiki Kaisha

InventorsDaisuke Ueo, Tomokazu Masuda

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Abstract

At the time of external charging, an external charging relay is turned on, and a system main relay is turned off. Therefore, a main battery can be charged by electric power from an external power source, without applying an output voltage of the main battery to a PCU. At the time of external charging, basically, a power supply voltage for an auxiliary system (low voltage system) is generated by a sub DC/DC converter of a small capacity, while a main DC/DC converter of a large capacity used when vehicle is running is stopped. Only when the output of sub DC/DC converter is insufficient to cover the power consumption by the auxiliary system, an ECU operates the main DC/DC converter. Therefore, ECU and auxiliary load group can be operated reliably while efficiency of external charging is improved.

Claims12

Dependent claims

A power source system for an electric powered vehicle chargeable by an external power source outside of the vehicle, comprising:

rechargeable main power storage device and sub power storage device;
a charger for converting electric power supplied from said external power source to an electric power for charging said main power storage device, at a time of external charging for charging said main power storage device by said external power source;
a power control unit for controlling driving of an electric motor for generating vehicle driving power, by electric power conversion between said main power storage device and said electric motor;
a first switch connected between said main power storage device and said power control unit;
a second switch connected parallel to said first switch, between said charger and said main power storage device;
a plurality of auxiliary loads formed to operate by the supply of electric power for auxiliary system from a power supply line connected to said sub power storage unit;
a first voltage converter for converting an output voltage of said main power storage unit to a level of an output voltage of said sub power storage device and outputting to said power supply line;
a second voltage converter, having an output capacity smaller than said first voltage converter, for converting an output voltage of said charger to the level of the output voltage of said sub power storage device and outputting to said power supply line;
and
a controller operated by electric power supplied from said sub power storage device, for controlling open/close of said first and second switches as well as operation and stop of said first and second voltage converters;
wherein
said controller is adapted such that
at the start of said external charging, said first switch is opened and said second switch is closed, said first voltage converter is stopped and said second voltage converter is operated, and when the electric power for said auxiliary system is determined to be insufficient during execution of said external charging, said first voltage converter is operated.

10 more elements

A method of controlling a power source system for an electric powered vehicle chargeable by an external power source outside of the vehicle;

wherein
said power source system including
rechargeable main power storage device and sub power storage device,
a charger for converting electric power supplied from said external power source to an electric power for charging said main power storage device, at a time of external charging for charging said main power storage device by said external power source,
a power control unit for controlling driving of an electric motor for generating vehicle driving power, by electric power conversion between said main power storage device and said electric motor,
a first switch connected between said main power storage device and said power control unit,
a second switch connected parallel to said first switch, between said charger and said main power storage device,
a plurality of auxiliary loads formed to operate by the supply of electric power for auxiliary system from a power supply line connected to said sub power storage unit,
a first voltage converter for converting an output voltage of said main power storage unit to a level of an output voltage of said sub power storage device and outputting to said power supply line, and
a second voltage converter, having an output capacity smaller than said first voltage converter, for converting an output voltage of said charger to the level of the output voltage of said sub power storage device and outputting to said power supply line;
said control method comprising the steps of:
confirming that said first switch is opened at the start of said external charging:
when opening of said first switch is confirmed, closing said second switch, and activating said second voltage converter;
after closing said second switch, externally charging said main power storage device by an output of said charger;
and
if the electric power for said auxiliary system is determined to be insufficient during said external charging, operating said first voltage converter.

13 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/321,039Filed 7 Aug 2009
Published: US 2012/0123625 A117 May 2012
Granted: 2 Jul 2013
Term ends: Not estimatedThe source records don’t support an estimate.

Classification16 codes

B60L 3/003
Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train: relating to inverters
B60L 50/16
Using propulsion power supplied by engine-driven generators, e.g. generators driven by combustion engines: with provision for separate direct…
B60L 50/51
Using propulsion power supplied by batteries or fuel cells: characterised by AC-motors
B60L 53/14
Characterised by the energy transfer between the charging station and the vehicle: conductive energy transfer