Japan Aerospace Exploration Agency

Japan Capacitor Industrial Co., Ltd.

Tsutomu Sekido

Akio Kukita

Masatoshi Uno

Kazushige Ito

Kaoru Nagata

Kazuhiro Shoji

An equalization circuit system having a system configuration simplified through reduction of the total number of switches is provided. An electricity storage cell voltage equalization circuit is operated with a square wave voltage generated at a switching node in an electricity storage module voltage equalization circuit as an input voltage, thereby achieving an electricity storage cell voltage equalization circuit without a switch. Typically, the electricity storage cell voltage equalization circuit may be a resonance voltage-doubling rectifier circuit, and the electricity storage module voltage equalization circuit may be a switched capacitor, a resonance voltage-doubling rectifier circuit, a buck-boost converter or the like.

Voltage equalization circuit system

An electric energy storage system is designed to equally utilize electric energy storage banks during charging/discharging, and keep fluctuation of an input voltage from a charger or an output voltage to a load, within an arbitrary range, while equally utilizing the electric energy storage banks during charging/discharging. The electric energy storage system comprises an electric energy storage module, a charger, a balancing circuit, a voltage detection section, taps led out, respectively, from one of opposite terminals of the electric energy storage module and/or the other terminal of the electric energy storage module and/or one or more of series-connection points between the electric energy storage units, through respective switches, and a switch control section for switching the switches such that one of the taps is connected to one of opposite terminals of the charger. The switch control section is operable to sequentially switch the switches according to progress of the charging.

Electric energy storage units connected in series and selectively charged/discharged via a balancing circuit or directly from a charger or to a load

An electric energy storage apparatus can generate an AC output in a low-loss and low-noise manner without using a DC-DC converter or an inverter. The electric energy storage apparatus comprises: an electric energy storage module group formed by connecting in series electric energy storage modules each comprising one or more electric energy storage elements; a balancing circuit electrically connected to the electric energy storage module group and configured to adjust a voltage to be applied to each of the electric energy storage modules; a first switch group comprising switches each in a path connecting a first terminal and a terminal of one of the series-connected electric energy storage modules; and a second switch group comprising switches each in a path connecting a second terminal and a terminal of one of the series-connected electric energy storage modules. The electric energy storage apparatus may perform a switch changeover in the switch groups.

Electric energy storage apparatus capable of AC output

It is an object to provide a circuit for equalizing voltages of energy storage cells, with less number of element and simpler circuit configuration than ever before. A plurality of field-effect transistors are arranged such that each of a plurality of parallel circuits formed, in one of connection states attained by switching of the switches, by connecting in parallel energy storage cells to perform mutual charging and discharging, includes a field-effect transistor adapted to avoid blocking a current having one of opposite polarities in the each of the plurality of parallel circuits, and a field-effect transistor adapted to avoid blocking a current having the other polarity in the each of the plurality of parallel circuits. This makes it possible to perform a voltage equalization operation using a small number of transistors.

Growing community of inventors

Fussa, Japan

Tsutomu Sekido