基于Z源变换器的电动汽车超级电容-电池混合储能系统

Z源变换器具有单级升压、降压、无死区、电压畸变小、可靠性高等优点,在电动汽车领域具有广阔的前景。提出一种基于Z源变换器的电动汽车超级电容-电池混合储能系统。该结构将储能与驱动系统相融合,减少了电池功率变换器,降低了损耗与成本。详细分析通过Z源变换器实现混合储能系统不同模式下功率分配的运行机理。此基础上提出功率分频协调控制策略以提高混合储能系统的响应速度并实现各模式的无缝切换。最后,为了避免短时尺度冲击电流对电池的影响,设计电池瞬态峰值电流估计方法。仿真与实验结果验证了所提出的混合储能系统及控制策略的有效性。

Implementation of Z-Source Converter for Ultracapacitor-Battery Hybrid Energy Storage System for Electric Vehicle

The Z-source converter features stepping up/down in single stage,none dead-time and high reliability,which attaches great significance to electric vehicles (EV).An ultra capacitor-battery hybrid energy storage system (HESS) for electric vehicles is proposed based on bi-directional Z-source topology.The HESS is incorporated in the traction inverter system,and the DC-DC converter for the battery is omitted.The steady operation principles for power distribution in HESS modes are analyzed.A frequency dividing coordinated control is then employed to enhance the system dynamic response and the seamless switching.Estimation methods for the battery peak current are also investigated,to avoid the impacts of short-time inrush current on battery.Finally,the steady performance and transient response are verified by simulation and experimental results.