Power device

Patent metadata

Field	Value
Publication number	US-10298147-B2
Application number	US-201815951724-A
Country	US
Kind code	B2
Filing date	Apr 12, 2018
Priority date	Apr 28, 2017
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

A power device includes a semiconductor relay and a pre-charger that has a reference voltage generator and a controller. The semiconductor relay is disposed at a position between a battery supplying electric power to a power converter that serves as a load and a smoothing capacitor connected on a battery side of the power converter in parallel with the power converter. The reference voltage generator generates a reference voltage having a gradually-increasing voltage value in a pre-charge period, prior to a turning ON of the semiconductor relay accompanying a turning ON of an ignition switch. The controller controls the semiconductor relay such that a charge voltage which is an inter-terminal voltage of the smoothing capacitor is set to a preset value according to the reference voltage.

First claim

What is claimed is:

1. A power device comprising:
a semiconductor relay disposed at a position between a direct current power source and supplying electric power to a load and a smoothing capacitor connected on a power source side of the load in parallel with the load;
a reference voltage generator generating a reference voltage that has a voltage value gradually increasing in a pre-charge period during which the smoothing capacitor is charged before a turning ON of the semiconductor relay; and
a controller controlling the semiconductor relay to have a preset value as an inter-terminal voltage of the smoothing capacitor according to the reference voltage,
wherein
the reference voltage generator generates the reference voltage with the voltage value that linearly changes,
the pre-charge period is divided into a plurality of sub-periods, and
the reference voltage generator generates the reference voltage that has a different per-unit-time voltage change amount in the respective sub-periods and a constant per-unit-time voltage change amount in each of the sub-periods.

2. The power device in claim 1 , wherein
the reference voltage generator generates the reference voltage that has a constant inclination throughout the pre-charge period, the constant inclination of the reference voltage indicative of the per-unit-time voltage change amount being set as a constant value.

3. The power device in claim 1 , wherein
the reference voltage generator generates the reference voltage such that, when a time from a start of the pre-charge period to a start of the sub-period is longer, the per-unit-time voltage change amount becomes greater.

4. The power device in claim 1 , wherein
the reference voltage generator includes a constant current circuit outputting a constant electric current and a reference capacitor generating the reference voltage by using the constant electric current.

5. The power device in claim 1 , wherein
the reference voltage generator includes a counter counting up by a preset value at a preset interval and a D/A converter outputting the reference voltage according to a count-up value of the counter.

6. The power device in claim 4 , wherein
the reference voltage has a negative temperature characteristic.

Assignees

• Denso Corp

Inventors

• Imura Takashi

Classifications

• H02M7/5375 Primary

  with special starting equipment · CPC title

• H02M7/53871

  with automatic control of output voltage or current · CPC title

• H02M1/36

  Means for starting or stopping converters · CPC title

• H03K17/145

  in field-effect transistor switches · CPC title

• H02M2001/0038

  Electricity · mapped topic