Automotive electric power supply system

摘要

The main electric power source is connected to a lower-voltage side of a DC/DC converter by a first switch, and an electrical double-layer capacitor and a regulator circuit is connected to a higher-voltage side of the DC/DC converter. In addition, permanent magnets are disposed on a rotor so as to generate a magnetic field that is in a reverse direction to excitation by a field coil inside a claw-shaped magnetic pole portion of the rotor. A power supply control circuit controls opening and closing of the first switch so as to be in an open state when the engine is at rest, and so as to be set to a connected state after the regulator circuit is operated to make the alternator generate electric power to precharge the electrical double-layer capacitor after the engine is started.

主权项

1. An automotive electric power supply system comprising:
a non-insulated DC/DC converter that is configured so as to be able to convert voltage bidirectionally between a higher-voltage input/output terminal and a lower-voltage input/output terminal; an automotive main electric power source that is connected to said lower-voltage input/output terminal of said DC/DC converter by a first switch; a capacitor that is connected to said higher-voltage input/output terminal of said DC/DC converter, and that has a rated maximum value that is a higher voltage than a rated voltage of said main electric power source; an alternator that is connected to said higher-voltage input/output terminal of said DC/DC converter, and that has a Lundell rotor to which a field coil is mounted, said alternator being driven to rotate by an engine to generate electric power; a permanent magnet that is disposed on said rotor, and that generates a magnetic field that is in a reverse direction to excitation by said field coil inside a claw-shaped magnetic pole portion of said rotor; a regulator circuit that is connected to said higher-voltage input/output terminal of said DC/DC converter, and that supplies electric power to said field coil; a starter motor that starts said engine; and a power supply control circuit that controls opening and closing of said first switch so as to be in an open state when said engine is at rest, and so as to be set to a connected state after said engine is started such that said regulator circuit is operated to make said alternator generate electric power such that said alternator precharges said capacitor, wherein said power supply control circuit is configured so as to set said first switch to said connected state, and then operate said DC/DC converter to step up said voltage of said main electric power source to said rated maximum value of said capacitor, and also to operate said regulator circuit to make said alternator generate electric power, and to charge generated electric power from said alternator to said capacitor, wherein said power supply control circuit is configured so as to set said first switch to said connected state, on detecting that said voltage of said precharged capacitor is higher than said voltage of said main electric power source.