Postech Academy-industry Foundation

Kyung Min Lee

Bong Koo Kang

Chang Hyeon Sung

Yoo Chae Chung

Min Gi Cho

Hyung Jin Choe

Ho Young Yoon

Sang Won Lee

Yoon Geol Choi

The present invention relates to a technique for implementing a bidirectional DC-DC converter applied to an energy storage system. The bidirectional DC-DC converter includes a magnetically coupled inductor and a charging/discharging voltage storage unit between a DC link power supply and a battery power supply, and implements a high gain through a two-step voltage transformation process when a charging process or discharging process is performed. Thus, the bidirectional DC-DC converter can reduce the construction cost of the battery cell, guarantee a high voltage available range, and reduce the influence of leakage inductance.

Bidirectional DC-DC converter

The present invention relates to a method for more efficiently performing a balancing operation for a plurality of battery cells of which charges are not equal, in a battery cell balancing circuit using an LC series resonant circuit. The method may include calculating balancing charge for all battery cells of which the charges are not equal, selecting the strongest battery cell storing the highest charge and the weakest battery cell corresponding to the strongest battery cell, among the entire battery cells, and performing a series of balancing operations.

Battery cell balancing method

The present invention relates to a technology capable of improving the use time of a battery cell by generally or individually controlling charge or discharge with respect to a multi-battery cell by using LC serial resonance in a module with a multi-battery cell structure. To this end, the present invention includes a battery module including a plurality of serially connected battery cells, a serial resonant circuit including serially connected inductor and capacitor and performing a serial resonant function, and first to third switch units that set an electric energy collection path and an electric energy supply path between the battery module and the serial resonant circuit.

Battery cell balancing circuit using LC serial resonance

Provided is a battery cell balancing circuit including: a battery cell module including a plurality of battery cells connected in series; a series resonant circuit including an inductor unit and a capacitor unit which are connected in series so as to store electric energy recovered from a corresponding battery cell of the battery cell module and supply the stored electric energy to a corresponding battery cell of the battery cell module; and a switch unit configured to provide an electric energy recovery path for storing the electric energy recovered from the corresponding battery cell of the battery cell module into the capacitor unit of the series resonant circuit and provide an electric energy supply path for supplying the stored electric energy to the corresponding battery cell of the battery cell module.

Growing community of inventors

Daejeon-si, South Korea

Kyung Min Lee