1. Design and Implementation of an 18-kW 500-kHz 98.8% Efficiency High-Density Battery Charger With Partial Power Processing
- Author
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Rolando Burgos, Dong Dong, Agirman Ismail, Minh Ngo, Yuliang Cao, and Ning Yan
- Subjects
Battery (electricity) ,business.industry ,Computer science ,Electrical engineering ,Energy Engineering and Power Technology ,Energy storage ,Power (physics) ,law.invention ,Battery charger ,law ,Voltage regulation ,Electrical and Electronic Engineering ,business ,Transformer ,Voltage ,Power density - Abstract
The demand for high-density, high-efficiency bi-directional battery chargers is driven by the fast development of energy storage system in renewable energy system, micro-grid, and transportation electrification. Isolated dc-dc converter that interfaces a battery with a variable voltage range is one of the critical components. Input-parallel output-series (IPOS) partial power (PP) converter is considered a promising high-efficiency, high density solution because only a fraction of power is processed via multi-stage converters to regulate the output voltage. However, due to the tight coupling between two dc transformers (DCXs), the design of PP converter is complicated. To solve this issue, a design procedure for a bi-directional soft-switching resonant type PP converter is proposed. In the parameters design part, a decoupled design method is proposed to simplify the DCXs design. With this method, two DCXs can be designed separately, and the typical optimization method can be easily applied. As for the hardware design part, to minimize the ac loop inductance and resistance, a 2-directions (2-D) flux cancelation method and an “intra-leaving” winding structure are proposed for circuit layout and high-frequency transformer to obtain high operation efficiency and power density. Finally, the whole design procedure is verified by an 18 kW rated, 25 kW peak, prototype operating at 500 kHz. The realized PP converter features a peak efficiency of 98. 8% and a power density of 142 W/in3. This article is accompanied by two videos demonstrating the dynamic voltage regulation test and the efficiency measurement.
- Published
- 2022
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