小母线电容电动汽车集成充电系统控制研究

Research on Control Schemes for Charging Integrated System of Electric Vehicle With the Small Bus Capacitor

研究了一种电动汽车电机驱动与车载充电集成系统的充电控制策略。该集成系统通过共用电机驱动和车载充电的功率变换电路,并将电机绕组用作充电电感,可减小电动汽车功率变换电路的空间占用和成本。此外,该集成系统直流母线采用小容值薄膜电容取代传统大电解电容,不仅可进一步减小系统体积,还可提高系统可靠性。该系统在充电状态下,电网侧变换器工作于二极管整流模式,母线呈现直流半波脉动电压。针对该工作特点,研究了基于Boost电路工作原理的电池侧双有源隔离型直流变换器正弦功率充电控制策略,在直流半波脉动母线电压条件下实现了电池有效充电,同时保证了电网电流具有良好的谐波性能和功率因数性能。最后通过实验样机对该控制策略的有效性进行了验证。

A charging control strategy is studied for an integrated system comprising motor drive and on-board charger of electric vehicle.This integrated system can reduce the space occupation and cost of the electric vehicle power conversion circuit by sharing power conversion circuits of the motor drive and on-board charger and using the motor windings as the grid inductance for charging.In addition,this integrated system replaces traditional large electrolytic capacitor with the small film capacitor in direct current link,which further reduces the system volume,improves the system reliability.In the charging operation of this system,the grid-side converter works in the diode rectifier mode,and the half-wave pulsating voltage appears in direct current link.For this operation mode,a sinusoidal power charging control strategy for dual active isolated direct current converter of battery side is proposed based on the working principle of Boost circuit,which can realize the effective battery charging with half-wave pulsating direct current link voltage.Simultaneously,the proposed charging strategy ensures that the grid current offers good performance in current harmonic and power factor.The effectiveness of the proposed control strategy is verified by experimental prototype.