Japan Aerospace Exploration Agency

Japan Capacitor Industrial Co., Ltd.

Masatoshi Uno

Akio Kukita

Kazushige Ito

Tsutomu Sekido

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

[Problem] It is intended to provide a system, a related method and a minimum current detection and control system for, even when partial shading occurs in a string composed of a series connection of a plurality of solar cell modules, maintaining an output current of the whole. [Solution] By inputting an output voltage of the string into an inverter to convert the output voltage into an AC voltage and applying the AC voltage to the string via a multi-stage voltage multiplier rectification circuit, a compensation current is supplied to a shaded module on a priority basis to maintain an output current of the whole string while lowering an operating voltage of the shaded module by impedance generated on a pathway of the compensation current. Further provided are a system and the like constructed by multistage-connecting an output-side circuit section of one of various types of converters to the solar cell modules, and configured to supply a compensation current from the converter section to the shaded module on a priority basis.

Solar cell adjustment system, related method, and minimum current detection and control system

The disclosure describes a charge device capable of charging electricity storage cells while eliminating a voltage variation among the electricity storage cells without a need for at least a circuit section playing a role in voltage equalization among the electricity storage cells to be designed to have a large current capacity, and describes a charge-discharge device constructed by additionally equipping a discharging function with the charge device. Provided are a charge device and a charge-discharge device each of which comprises a convertor, an input circuit, and a multi-stage voltage doubler rectifier circuit. An element in the convertor configured to be applied with a rectangular waveform voltage is connected to the multi-stage voltage doubler rectifier circuit via the input circuit to thereby realize a voltage equalization function, and an output section of the convertor is connected to the multi-stage voltage doubler rectifier circuit to thereby realize a charging-discharging function.

Charge-discharge device with equalization function using both convertor and multi-stage voltage doubler rectifier circuit

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

Hitachi, Japan

Masatoshi Uno