120kW一机双充直流充电桩主电路拓扑与应用

Topology and Application of the Main Circuit for 120kW Dual-Gun Integrated DC Charging Pile

摘要

针对新能源汽车大功率快充需求，本文设计一款120kW一机双充直流充电桩系统，采用三相三电平VIENNA整流器+全桥 LLC谐振变换器组合拓扑，实现双枪独立输出、宽电压范围充电与高效率运行目标。控制策略采用电压电流双闭环 PFC控制、频率调节式LLC控制以及基于虚拟阻抗的双枪均流算法，提升系统动态响应与输出一致性。通过样机测试验证，系统效率≥95%，功率因数≥0.99，双枪输出电流偏差<2%，满足大功率直流充电设备标准要求。研究结果可为大功率一机双充充电桩工程化设计提供参考方案。

Abstract

To address the high-power fast-charging demands of new energy vehicles, this paper proposes a 120 kW single-unit dual-charger DC charging station system. The system employs a combined topology consisting of a three-phase three-level VIENNA rectifier coupled with a full-bridge LLC resonant converter, aiming to achieve independent output from both chargers, wide voltage-range charging capability, and high operational efficiency. The control strategy incorporates a dual closed-loop voltage-current PFC control scheme, a frequency-adjusted LLC control method, and a dual-charger current balancing algorithm based on virtual impedance, thereby enhancing the system’s dynamic response and output consistency. Through prototype testing, the system efficiency was verified to be ≥95% and the power factor was ≥0.99; the output current deviation for the dual-charger configuration was <2%, thereby complying with the standard requirements for high-power DC charging equipment. These research findings can serve as a reference for the engineering design of high-power dual-charging charging stations.

关键词

120kW直流充电桩 / 一机双充 / VIENNA整流器 / LLC谐振变换器 / 均流控制

Key words

120kW DC charging pile / dual-gun integrated charging / VIENNA rectifier / LLC resonant converter / current sharing control

参考文献

[1] 张兴, 曹仁贤, 余畅舟. 三相三电平 VIENNA 整流器的建模与控制策略[J]. 中国电机工程学报, 2022, 42 (18): 6321-6330.

[2] 郭殿林, 杨成, 于孟然. 高功率密度充电桩前级VIENNA整流器的双闭环设计[J]. 黑龙江科技大学学报, 2019, 29 (2): 167-173.

[3] 李建林, 惠东, 胡书举. 基于 SiC MOSFET的LLC谐振变换器宽电压输出控制方法[J]. 电力系统自动化, 2023, 47 (10): 158-165.