Hitachi Automotive Systems, Ltd.

Hitachi Astemo Ltd.

Naoya Takahashi

Takae Shimada

Kenji Kubo

Hiroyuki Shoji

Takayuki Ouchi

Shintaro Tanaka

Fumihiro Sato

Takuya Ishigaki

Yuji Sobu

Eigo Kishimoto

Takuma Ono

There is provided a switching power supply device which has a high voltage control resolution. A switching power supply device according to the present invention includes: a power conversion circuit which includes a switching element; and a control circuit unit which outputs a driving pulse to the switching element based on an output voltage command value and an output voltage value of the power conversion circuit, and the control circuit unit changes a switching cycle and outputs a driving pulse based on a difference between a calculation value of an operation amount based on the output voltage command value and the output voltage value, and a setting value of the operation amount.

Switching power supply device

A switching loss of a power conversion device is sufficiently reduced. A DC-DC converter includes a switching circuit that converts input first DC power into AC power, a transformer that performs voltage conversion of the AC power, and an output circuit that converts the AC power subjected to the voltage conversion by the transformer into second DC power. The control circuit that controls the DC-DC converter calculates a magnetic flux density value B of the transformer and controls a drive frequency of the switching circuit based on the calculated magnetic flux density value B.

Control device with magnetic flux density calculation

An object of the present invention is to provide a charging apparatus having high efficiency of charging a battery by inputting an alternating current voltage. A charging apparatus that charges a direct current battery includes a step-down converter unit to which a direct current voltage from a power supply is input and that converts the direct current voltage, and when a voltage of the direct current battery is between a predetermined first voltage smaller than a charge completion voltage of the direct current battery and the charge completion voltage, a variable voltage that increases from the first voltage to the charge completion voltage in accordance with charging of the direct current battery is input to the step-down converter unit.

Power supply apparatus

There is a disadvantage that a loss generated in a charging apparatus becomes large. It is determined whether a link voltage Vo is equal to or higher than a predetermined value Va. If the link voltage Vo is less than the predetermined value Va, a control unit activates a DC-DC converter in a boosting operation. That is, by turning on/off the switching element, the voltage boosted from the storage battery is supplied to the link voltage Vo. The control unit determines whether the link voltage Vo is equal to or higher than the predetermined value Va. If the link voltage Vo is less than the predetermined value Va, the operation is continued. When the link voltage Vo rises due to the boosting operation of the DC-DC converter and becomes equal to or higher than the predetermined value Va, the boosting operation of the DC-DC converter is stopped.

Charging apparatus

Growing community of inventors

Hitachinaka, Japan

Naoya Takahashi