分布式电源系统启动稳定性研究

Research on the startup stability of the distributed power supply system

分布式电源系统在启动时,会面临级联电路带来的母线电压振荡及异常工作电压等稳定性问题,因此需要进行针对性设计和改进。本文针对两级Buck电路级联电源系统,基于功率守恒原理建立大信号系统模型,直观地分析了系统启动过程中各个模块软启动工作原理及出现关断重启现象的原因,并推导出级联电源系统启动稳定性的关键参数公式。接着对系统进行行为级建模仿真,在满足电路性能需求的基础上,验证了通过合理设置两级电源输出电容、负载电源启动点、系统软启动时间等以符合启动稳定性参数公式,可保证分布式电源系统的启动稳定性。

When the distributed power supply system is started,stability issues caused by cascaded circuits may occur,such as the oscillation of the bus voltage and abnormal operating voltage.It is necessary to carry out the targeted design and improvement.For the cascaded power supply system composed of the two-stage buck circuit,this paper establishes the model of large signal system on the principle of power conservation.Then the soft-start working principle of each module and the reason of the shutdown-restart phenomenon during the startup process are analyzed.Besides,the key-parameter formula for the startup stability of the cascaded power supply system is developed.Finally,this paper conducts behavioral modeling and simulation of the system on the basis of meeting the performance requirements of the circuit,the simulation verifies that the startup stability of the distributed power supply system can be guaranteed by satisfying the key-parameter formula,which can be implemented by correctly setting the two-stage power output capacitors,the start point of the load power supply and the soft start time of the power supply system.