Other

Hitachi, Ltd.

Hitachi Computer Peripherals Co., Ltd.

Hitachi Maxell, Limited

Hitachi Maxwell, Ltd.

Satoru Masuyama

Kenichi Onda

Norikazu Tokunaga

Ryouhei Saga

Takeshi Onaka

Akihiko Kanouda

Masato Isogai

Katsunori Hayashi

Shigekazu Zemba

Nobuyuki Aihara

The present invention reduces the capacity of the AC-DC converter for the peak load and realizes low price and reduction in the volume of the power unit. The apparatus built-in backup power supply has the peak cut function for sharing a part of the load current at the time of peak load from the secondary battery. The two-way DC-DC converterand the secondary batteryare installed on the DC output side of the AC-DC converterand a current larger than a predetermined peak cut level is discharged from the secondary batteryat the time of peak load. Further, when the load is less than the predetermined cut level, the secondary batteryis charged from the AC-DC convertervia the two-way DC-DC converter. Furthermore, a most suitable peak cut level according to the SOC of the secondary battery and load pattern is automatically set and dynamically changed.

Backup power supply

A power supply provided with: an AC/DC converter which receives AC power, converts the AC power into DC power, and outputs the DC power; a DC/DC converter which receives the DC power from the AC/DC converter, and controls a level of an output voltage of the DC/DC converter to be equal to a level of a voltage to be used by a load while the DC/DC converter supplies the output voltage to the load; a DC converter which is connected to an input of the DC/DC converter; and a DC power storage means which supplies electric power to the DC/DC converter through the DC converter.

Power supply with uninterruptible function

Apparatus built-in backup power supply system has a 'peak cut' function for sharing a part of the load current at the time of a peak load using a secondary battery. For this purpose, a two-way DC&#x2014;DC converterand the secondary batteryare installed on the DC output side of the AC-DC converterand that portion of the load current that exceeds a predetermined peak cut level is discharged from the secondary batteryduring peak loading. When the load is less than the predetermined cut level, the secondary batteryis charged from the AC-DC convertervia the two-way DC&#x2014;DC converterA suitable peak cut level is determined according to the state of charge of the secondary battery and load pattern, and is changed dynamically.

A power supply provided with: an AC/DC converter which receives AC power, converts the AC power into DC power, and outputs the DC power; a DC/DC converter which receives the DC power from the AC/DC converter, and controls a level of an output voltage of the DC/DC converter to be equal to a level of a voltage to be used by a load while the DC/DC converter supplies the output voltage to the load; a DC converter which is connected to an input of the DC/DC converter; and a DC power storage device which supplies electric power to the DC/DC converter through the DC converter.

A DC power supply device comprises an AC/DC converter , a DC/DC converter , and a DC converter 3 converting DC power from a battery to DC voltage for connecting to output terminals of the AC/DC converter. The DC power supply device is provided with a controlling circuit which observes a charging control level and a load sharing level, impresses a charging command on a UPS controlling part controlling the DC converter, and simultaneously provides a PFC controlling part controlling the AC/DC converter with a current command when a voltage level is less than the charging control level, stops only the charging command when the voltage level is more than the charging level and less than the load sharing level, and provides the UPS controlling part and the PFC controlling part with current commands when the voltage level is more than the load sharing level. The AC/DC converter and the DC converter supply power in parallel when a load is more than a prescribed value, and the DC converter supplies power as a backup when a trouble is present in an AC power input.

DC power supply device

A DC power supply device comprises an AC/DC converter , a DC/DC converter , and a DC converter converting DC power from a battery to DC voltage for connecting to output terminals of the AC/DC converter. The DC power supply device is provided with a controlling circuit which observes a charging control level and a load sharing level, impresses a charging command on a UPS controlling part controlling the DC converter, and simultaneously provides a PFC controlling part controlling the AC/DC converter with a current command when a voltage level is less than the charging control level, stops only the charging command when the voltage level is more than the charging level and less than the load sharing level, and provides the UPS controlling part and the PFC controlling part with current commands when the voltage level is more than the load sharing level. The AC/DC converter and the DC converter supply power in parallel when a load is more than a prescribed value, and the DC converter supplies power as a backup when a trouble is present in an AC power input.

Growing community of inventors

Odawara, Japan

Satoru Masuyama