基于频率分割和虚拟直流机的混合储能控制策略研究

Study on Hybrid Energy Storage Control Strategy Based on Frequency Divider and Virtual Direct Current Generator

针对直流微电网混合储能中能量电池使用寿命的问题,设计频率分割器和功率调节环节,通过对系统净功率进行分割,提升混合储能的平抑效果和能量电池的使用寿命。并考虑到微电网储能变换器低惯量和弱阻尼的特点,采用虚拟直流发电机控制策略,提升系统的暂态稳定性。仿真结果表明,相较于传统PI控制,所设计的控制策略可以使母线电压波动小于0.53%;并且能量电池的功率波动和功率电池相比,变化趋势明显更加平缓。

Aiming at the problem of the service life of the energy battery in the hybrid energy storage of the DC microgrid, a frequency divider and a power regulation link are designed. By dividing the net power of the system, the smoothing effect of the hybrid energy storage and the service life of the energy battery are improved. Taking into account the low inertia and weak damping characteristics of the microgrid energy storage converter, the virtual DC generator control strategy is adopted to improve the transient stability of the system. The simulation results show that, compared with the traditional PI control, the designed control strategy can make the bus voltage fluctuation less than 0.53%. And the power battery’s power fluctuation is significantly smoother than that of the power battery.