Hitachi Computer Peripherals Co., Ltd.

Hitachi Information & Telecommunication Engineering, Ltd.

Hitachi, Ltd.

Hitachi Maxell, Limited

Nok Corporation

Hitachi Maxwell, Ltd.

Yoshihide Takahashi

Fumikazu Takahashi

Akihiko Kanouda

Masahiro Hamaogi

Takae Shimada

Kimiaki Taniguchi

Hiroyuki Shoji

Minehiro Nemoto

Masato Isogai

Isao Nemoto, Legal Representative

Takashi Tanabe

Takao Gotou

Toshikatsu Miyata

Akinori Uchida

Yusuke Katsuyama

Susumu Nagafuchi

Hirokazu Yamamoto

Yutaka Koda

Tamio Inamura

Nobuyuki Aihara

Yusuke Ikawa

Kuniyoshi Watanabe

Wataru Mochizuki

Daisuke Ishida

A power storage system is provided with charge switches, discharge switches, a bidirectional DC/DC converter and a power storage system controller connecting all the battery packs to an external circuit to achieve parallel charge and discharge, and the power storage system starts the charge by setting a rated charge current value per one battery pack to Iset and setting the rated charge current value Iset as an initial value of a charge current command value Iref(1), thereafter monitor the charge current of each of the battery packs after elapse of a predetermined time so as to subtract its maximum value Ibmax(1) from the charge current command value Iref(1), and add the rated charge current value Iset to result of subtraction Ierr (Iref(1)&#x2212;Ibmax(1)) so as to set as a new charge current command value Iref(2) and carry out pre-charge in such a manner as to carry on the charge.

Power storage system and power source system

A hollow fiber membrane module comprising a bundling tube including a body part and head parts placed at both terminals of the body part and O-rings with which the bundling tube is fitted into a housing being attached to outer circumferential surfaces of the head parts, wherein at least one of the head parts are divided into two in a place closer to a terminal of the bundling tube than places where the O-rings are attached while maintaining a cylindrical shape of the head part, and the divided parts have a slidable structure while maintaining a coupled condition therebetween that forms the cylindrical shape. The hollow fiber membrane module is capable of preventing damage effectively on a hollow fiber membrane or the bundling tube due to expansion or contraction of the hollow fiber membrane to be caused by change of an external environment such as temperature.

Hollow fiber membrane module

A power storage system is provided with a battery and a battery charger which charges a battery pack having a battery voltage and current detection circuit. A charge circuit is structured such as to acquire terminal voltage information of the battery from a battery voltage detection circuit of the battery pack in a charging process, carry out a constant current charge control in a state in which the terminal voltage of the battery is equal to or lower than a previously determined reference voltage value of the battery, and switch to a constant voltage charge control maintaining the output voltage of the charge circuit in the case that the terminal voltage of the battery goes beyond the reference voltage value, thereby carrying on the charge until the battery is fully charged. Therefore, the power storage system can accurately charge the battery to a prescribed amount safely.

Power storage system with constant current charge control or constant voltage charge control depending on battery terminal voltage in a charging process

A highly efficient power supply unit compatible with a single-phase three-wire system and an operating method of such a power supply unit are provided. The power supply unit includes first and second switching legs connected in parallel to a first capacitor leg with a DC power supply connected thereto. One end of the second capacitor leg is connected to the middle point of the first switching leg through a first inductor, and the other end is connected to the middle point of the second switching leg through a second inductor. The two ends of the second capacitor leg and the middle point of the second capacitor leg are defined as AC terminals. A switch is provided between middle points of first and second capacitor legs. A control part sets the switch to OFF when power is input/output only between one end of the second capacitor leg and the other end.

Power supply unit for converting power between DC and AC and operating method of the same

A bi-directional DC-DC converter has a transformer for connecting a voltage type full bridge circuit connected to a first power source and a current type switching circuit connected to a second power source. A voltage clamping circuit constructed by switching elements and a clamping capacitor is connected to the current type switching circuit. The converter has a control circuit for cooperatively making switching elements operative so as to control a current flowing in a resonance reactor.

Bi-directional DC-DC converter and method for controlling the same

To provide a smaller and more efficient switching power supply, the switching power supply includes: a high frequency transformer; a primary side switching circuit adapted to switch a current flowing through a primary winding of the high frequency transformer to thereby generate predetermined voltages in a secondary winding and an auxiliary winding of the high frequency transformer; a secondary side rectifier adapted to rectify a voltage generated in the secondary winding to supply the rectified voltage to a load; a charging circuit adapted to rectify a current flowing through the auxiliary winding and to switch the rectified current to thereby charge a secondary battery at a constant current; and a switch, provided between the secondary battery and the load, which supplies, when the voltage supplied to the load is interrupted, the voltage of the secondary battery to the load without going through the high frequency transformer.

Switching power supply

A DC backup power supply system having a plurality of loads to which AC from a commercial power source is supplied, and DC power storage means for supplying DC power to the plurality of the loads at the time of a power outage of the commercial power source, said DC backup power supply system including: a control circuit having a first DC backup output for supplying a power from the DC power storage means to the plurality of the loads, including a specific load, only during the power outage of the commercial power source, and a second DC backup output for continuously supplying a power from the DC power storage means to the specific load regardless of the power outage of the commercial power source or sound operation thereof, the control circuit supplying the respective powers from the same DC power storage means to the first and second DC backup outputs.

DC backup power supply system, a disk array and a DC backup power supply

An object of the invention is to provide a small and low-cost switching power supply unit with a backup function in which a proper circuit construction can be selected by simple method when it is necessary to compensate for the instantaneous drop or power failure and a disk array system having the switching power supply unit. To accomplish the object, a backup unit which can insert and pull out its hot line into a switching power supply unit casing and has a secondary battery and its state monitoring/control unit is built in the unit, and proper charge/discharge management of the secondary battery can be made. When the backup unit is unnecessary, a backup unit formed by a plurality of capacitors whose hot lines can be similarly inserted and pulled out can be built in an enclosing space of the backup unit.

Switching power supply unit and disk array system

To provide a power supply apparatus having high control resolution of an output power. A PWM signal generating circuit includes: a non-inverting element, and an inverting element; and further includes a counterfor performing count operation in response to rising of a clock signal, a counterfor performing count operation in response to falling of the clock signal, comparison circuits, and a multiplexer. These circuit elements are controlled by PWM control means. As another circuit element, the PWM signal generating circuit includes a logical sum element. The PWM signal generating circuit serves to arbitrarily change both period and logic 'H' time of a PWM signal to be outputted at a time interval which is one half of the clock period. Thus, there is provided a power supply apparatus in which resolution of a PWM signal has been improved within a broad duty range, and fine control of an output power has been performed within a broad output power range.

PWM signal generating circuit and power supply apparatus comprising such PWM signal generating circuit

A backup power supply is so constructed that it is provided with multiple DC backup power suppliestoN, each containing nickel-metal hydride battery, stored upright on the bottom of the disk array unit; cooled by cooling air through the ventsfor ventilation from the bottom to the top; and connected with the output of the AC/DC converterswith the backboard Very compact disk array unit with an uninterruptible power supplying function can be realized.

Data processing unit and DC backup power supply

A DC backup power supply system having a battery a charge-discharge circuit for charging and discharging a power between the battery and a DC line and a control circuit for controlling the charge-discharge circuit, wherein the battery has a number of battery cells and cylindrical portions of the battery cells are laid on an approximately horizontal plane.

DC backup power supply system

In the case where there coexist general loads requiring backup only for a short duration and a specific load requiring backup for a longer duration, uninterruptible power with higher reliability is supplied to the specific load with the adoption of a simple configuration. A DC backup power supply system comprises an AC/DC converter for normally supplying DC power to loads in while (the general loads and the specific load, included), and a control circuit for supplying DC output backing up the loads in whole for relatively short time only from a battery at the time of a power outage, while supplying DC output backing up the specific load, such as a cache memory and so forth, for relatively long time. Thus, it is possible to implement an uninterruptible power supply system small in size and low in cost, provided with a function for proper use depending on a prevailing situation.

DC backup power supply system and disk array using same

A reliable uninterruptible DC power supply device. The DC backup power supply device includes an AC/DC converter, a DC/DC converter, voltage step-up/down choppers and a battery connected to a DC path of a main circuit connected with a load via a switch, and a microcomputer. In the device, under control of the microcomputer, the voltage step-up/down choppers are first operated under a condition that the MOS FET was turned OFF for self diagnosis of the backup power supply device. Next, the switch is turned ON to execute the remaining self diagnosis. The DC backup power supply device can execute its self diagnosis with a reduced likelihood of danger of exerting an adverse effect on the main circuit and also can exhibit a reliable uninterruptible power supply function.

Growing community of inventors

Odawara, Japan

Yoshihide Takahashi