可调电能质量的光伏系统双层控制策略

Double-layer control strategy for power quality regulation of PV system

分布式光伏电源渗透率上升会影响电能质量。为了充分发挥分布式光伏电源调节配电网电能质量的潜力,设计了分布式光伏发电系统双层控制策略。该控制策略包含中心控制层和本地控制层,其中,中心控制层实时检测电网和分布式电源的运行状态,决定功率调整方案;本地控制层采用了超级电容器和逆变器相互配合的新方案,并在超级电容器的双环控制结构中设计了功率前馈环节,提高了响应速度。仿真表明,设计方案能够使分布式光伏电源参与电网调频、调压、调度及灵活方便地调整自身储能元件能量状态,并有效保证直流母线电压稳定。

With the increased penetration of distributed photovoltaic （PV） power in distribution net- work, the influence of distributed PV on the stability and power quality of distribution network keeps rising. In order to make full use of distributed PV system＇s potential to control and regulate power quality, a double-layer control strategy for photovoltaie is designed. The proposed control strategy in- eludes central control and local control layer. The center controller monitors the real time state of grid and PV to decide power adjustment scheme; the local controller adopts a new scheme of super capaci- tor cooperated with inverter. A power feed-forward link is joined in the control of super capacitor to improve dynamic response. Simulation results show that the proposed scheme can make the distributed PV systems participate in frequency regulation, voltage adjustment, grid scheduling as well as en- ergy state control of super capacitor, at the same time, the stability of DC bus voltage is guaranteed.