ALTERNATING CURRENT SOURCE FOR DETECTING BATTERY INTERNAL RESISTANCE IN ALTERNATE CURRENT INJECTION METHOD AND CONTROL METHOD THEREOF

摘要

Disclosed in the present invention is an alternating current source for detecting battery internal resistance in alternate current injection method. The alternating current source comprises an isolating step-down circuit, a rectifying circuit, an inverter circuit and an inductance capacitance (LC) resonance circuit which are connected in turn. An output end of the LC resonance circuit is reversely connected to the inverter circuit through a control circuit to form a closed loop control system. A non-direct capacitor is used in the LC resonance circuit. Also disclosed in the present invention is a corresponding control method of the alternating current source. The invention can inject current into one or more groups of high-voltage battery packs using a very low busbar voltage, thereby greatly reducing voltage stress of a power semiconductor component, significantly improving reliability of the system and simultaneously obviously improving system efficiency.