车载综合电力系统关键参数对系统稳定性的影响

Effects of Key Parameters of Integrated Power System on Vehicle Stability

针对车载综合电力系统体积容量受限、变流器多、工况复杂等导致的易失稳问题,开展了系统稳定性研究。通过建立各微源、负载变换器的小信号模型,得到各微源输出阻抗与负载输入阻抗。基于改进的阻抗比判据并结合系统幅值和相位裕量需求,给出车载综合电力系统小信号稳定判据。利用波特图直观地考察车辆在静音行驶模式下超级电容、DC/DC滤波电感、直流侧电容、驱动电机转速与转矩等关键参数对系统的影响规律。仿真实验结果验证了该稳定判据的正确性和理论分析的合理性,同时为有效评估系统的稳定性、优化系统设计提出了合理化意见。

The instability of the vehicular integrated power system due to its limited volume capacity,more converters and complex working condition is studied.The small signal models of each source and load converter are proposed,from where the output impedance and load input impedance are obtained.The stability criterion of small signal of the vehicular integrated power system is established based on an improved impedance criterion in which the requirements of both the system amplitude and the phase margin are considered.The effects of super-capacitor,filter inductor of DC/DC converter,DC-link capacitor,and speed and torque of driving motor on the system in engine-off operation mode are analyzed by using Bode diagram.Finally,the stability criterion and the theoretical analysis are validated using the simulated results.The methods are used for the evaluation of system stability and the optimization of system design.