Power Decoupling Buck-boost Converter for Lithium-ion Battery Pulse Current Charging

In this paper, a power decoupling buck-boost converter is proposed for the lithium-ion battery power interface converters, aiming to achieve high quality pulse current (PC) charging. The proposed topology introduces a decoupling circuit into the original main buck-boost converter. The main circuit establishes a connection between the DC source and the battery, ensuring a constant charging power supply to the battery. The decoupling circuit operates in parallel with the main circuit to deliver periodic pulse power to the battery. Therefore, the proposed power decoupling topology significantly reduces the harmonic content and electromagnetic interference (EMI) of the lithium-ion battery PC charging power interface. The whole control scheme of the interface converter is given, and a dual-edge adaptive on-time (DAOT) control is proposed for the decoupling circuit, which realizes the accurate tracking of high-frequency AC pulse current. In addition, the transient performance is improved as the rise regulation time of the output PC waveform is reduced by 75% compared to that of the traditional single-level buck-boost converter. An experimental platform of 300kHz/210W is set up to verify the effectiveness of the proposed power decoupling topology and control strategy.