Remaining capacity equalizing device and method, and remaining capacity equalizing device set

摘要

A remaining capacity equalizing device is provided having an inductance connected to a reference node of a battery pack and first and second switching elements. A first closed circuit is formed through selecting sequentially a first switching switch from a first switching switch group that is connected to the high-voltage side of the reference node. A second closed circuit is formed by selecting sequentially a second switching switch from among a second switching switch group that is connected to the low-voltage side of the reference node. The first and second switching elements are turned ON/OFF alternatingly for each combination of first and second closed circuits so that, during a specific interval, the ratio of the conductive times of the first and second switching elements is the inverse of the ratio of the numbers of storage cells in the first and second closed circuits.

主权项

1. A remaining capacity equalizing device for equalizing the remaining capacities of a plurality of storage cells that are connected in series to form a battery pack, comprising:
an inductance having one end thereof connected to a reference node between mutually adjacent storage cells in the battery pack; first and second switching elements having one end each thereof connected to the other end of the inductance; a first switching switch group able to connect the other end of the first switching element to a high-voltage-side node of each storage cell of the battery pack that is connected on the high-voltage side of the reference node; a second switching switch group able to connect the other end of the second switching element to a low-voltage-side node of each storage cell of the battery pack that is connected on the low-voltage side of the reference node; and a controlling portion for controlling the ON/OFF switching of the first and second switching elements and the first and second switching switch groups;wherein:
the controlling portion:
selects and puts into a conductive state, one at a time, first switching switches from the first switching switch group, to form a first closed circuit that includes the selected first switching switch, the storage cells between the reference node and the high-voltage-side node to which the first switching switch is connected, the first switching element, and the inductance;selects and puts into a conductive state, one at a time, second switching switches from the second switching switch group, to form a second closed circuit that includes the selected second switching switch, the storage cells between the reference node and the low-voltage-side node to which the second switching switch is connected, the second switching element, and the inductance;alternatingly turns ON/OFF the first and second switching elements so that, for each combination of first and second closed circuits that are determined respectively by the selections of the first and second switching switches, the ratio of the conductive time of the first switching switch and the conductive time of the second switching switch during a specified interval is the inverse of the ratio of the number of storage cells included in the first closed circuit and the number of storage cells included in the second closed circuit; andrepeats a cycle wherein the first and second switching switches are switched sequentially.