Patent ID: 8928283
Filing Date: 2015-01-06
Classification: H01M,H02J,Y02E,Y02T

Abstract:
1. An electricity storage system comprising: a plurality of storage modules connected in series, each storage module including a single storage cell or a plurality of storage cells connected in series; an isolation transformer and a rectifying circuit that are associated with each of the storage modules, the isolation transformer having a primary winding and a secondary winding; a voltage balancing circuit that generates an alternating current by switching a direct-current power source; and a balance detection circuit that detects a difference between voltages on the storage modules, the primary windings of the isolation transformers being all connected in parallel and connected to an output end of the voltage balancing circuit by a common wiring, the secondary windings of the isolation transformers being connected to the corresponding storage modules via the respective rectifying circuits, the alternating current being supplied to the primary winding of each of the isolation transformers, in accordance with an output of the balance detection circuit, the voltage balancing circuit being configured to perform a switching operation in the case where there is a difference between or among voltages on the storage modules and increase a frequency of the switching as a difference between or among voltages on the storage modules becomes greater at the time of the switching operation.