基于混合储能电压源逆变器平抑微电网功率波动的方法研究

为了平抑间歇性微电源引起的功率波动,研究了基于超级电容和蓄电池的混合储能电压源逆变器（VSI）控制策略,设计了混合储能系统两级能量管理方法。将超级电容作为系统一级缓冲储能优先平抑微电网功率波动。并网运行时配电网作为二级储能,通过控制联络线功率,使超级电容端电压稳定在充放电限值以内,同时维持公共连接点（PCC）母线电压在允许范围内变化;孤岛运行时蓄电池作为二级储能,通过超级电容的缓冲作用减少蓄电池充放电次数,延长蓄电池使用寿命,当超级电容达到充放电警戒值时,精确控制蓄电池以恒功率输出,调节超级电容端电压恢复到正常值。仿真结果验证了方法的有效性。

Research on the Method for Smoothing Power Fluctuations in Microgrid Based on Hybrid Energy Storage Voltage Source Inverter

In order to smooth the power fluctuations caused by intermittent micro power source,the control strategy of hybrid energy storage based on super-capacitor and battery was researched and a two stage management method of hybrid energy storage was designed. To take full advantage of large power density and long cycle life of super-capacitor in charging and discharging,it is used as the first buffer energy storage to smooth the power fluctuations priority in this method. Distribution network is used as second energy storage when the microgrid is under grid-connected operation. The power of tie line is controlled to make the terminal voltage of super-capacitor within limits and maintain PCC bus voltage fluctuation within the permissible range. Battery is used as second energy storage when the microgrid is under island operation. The charging and discharging times of battery are reduced by the buffering effect of super-capacitor and the life of battery is prolonged. When the terminal voltage of supercapacitor reaches to alert value,battery is controlled accurately to constant power output,so the terminal voltage of super-capacitor is returned to normal value. The simulation results show that the method is effective.