Vehicle auxiliary power supply device and overcurrent protection method thereof

Patent metadata

Field	Value
Publication number	US-9595886-B2
Application number	US-201114359516-A
Country	US
Kind code	B2
Filing date	Nov 28, 2011
Priority date	Nov 28, 2011
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

A vehicle auxiliary power supply device includes a resonant inverter circuit that converts DC input into a desired AC voltage and outputs the AC voltage and a control unit. The control unit includes a resonance-time managing unit managing resonance time of current flowing in the resonant inverter circuit, a gate-off-command generating unit detecting overcurrent flowing in the resonant inverter circuit based on detected current of a current detector, and, when the overcurrent is detected, generating, based on detected current of the current detector and resonance time managed by the resonance-time managing unit, a gate-off command to turn off switching elements included in the resonant inverter circuit after the elapse of time after which current flowing in the switching elements becomes zero for the first time, and a gate-signal generating unit generating a gate signal that controls the switching elements to be turned off when the gate-off command is input.

First claim

The invention claimed is:

1. A vehicle auxiliary power supply device that is mounted on an electric vehicle and that includes a resonant inverter circuit that converts an input DC voltage into a desired AC voltage and outputs the AC voltage and a control unit that controls the resonant inverter circuit, wherein
a current detector is provided on an output side of the resonant inverter circuit, and
the control unit includes
a resonance-time managing unit that manages resonance time of a current flowing in the resonant inverter circuit,
a gate-off-command generating unit that detects overcurrent flowing in the resonant inverter circuit on a basis of a detected current of the current detector, and that, when the overcurrent is detected, generates, on a basis of a detected current of the current detector and resonance time managed by the resonance-time managing unit, a gate-off command to turn off a switching element included in the resonant inverter circuit after an elapse of time after which a current flowing in the switching element becomes zero for a first time, and
a gate-signal generating unit that generates a gate signal that controls the switching element such that the switching element is turned off when the gate-off command is input.

2. A vehicle auxiliary power supply device that is mounted on an electric vehicle and that includes a resonant inverter circuit that converts an input DC voltage into a desired AC voltage and outputs the AC voltage and a control unit that controls the resonant inverter circuit, wherein
a current detector is provided on an output side of the resonant inverter circuit, and
when overcurrent flowing in the resonant inverter circuit is detected on a basis of a detected current of the current detector, the control unit outputs a gate-off command to turn off a switching element included in the resonant inverter circuit after an elapse of time after which a current flowing in the switching element becomes zero for a first time.

3. An overcurrent protection method of a vehicle auxiliary power supply device that is mounted on an electric vehicle and that includes a resonant inverter circuit that converts an input DC voltage into a desired AC voltage and outputs the AC voltage, the method comprising:
a first determining step of determining whether a current flowing in the resonant inverter circuit is overcurrent;
a second determining step of, when overcurrent is detected at the first determining step, determining whether an elapsed time since the overcurrent was detected has reached resonance time; and
a gate-off-command generating step of, when the elapsed time has reached the resonance time at the second determining step, generating a gate-off command to turn off a switching element included in the resonant inverter circuit.

Assignees

• Achihara Masato
• Harada Ryotaro
• Mitsubishi Electric Corp

Inventors

• Achihara Masato
• Harada Ryotaro

Classifications

• Y02T10/72

  Electric energy management in electromobility · CPC title

• H02M7/537 Primary

  using semiconductor devices only, e.g. single switched pulse inverters · CPC title

• Y02T90/127

  Cross-Sectional Technologies · mapped topic

• Y02T90/14

  Plug-in electric vehicles · CPC title

• B60L2210/00

  Converter types · CPC title