考虑需求侧管理的孤岛微电网频率协调控制策略

Coordinated control strategy of island microgrid frequency considering demand side management

大量分布式电源通过电力电子装置接入微电网,降低了系统的等效惯性,使得微电网孤岛运行时的频率问题尤为突出。为了提高孤岛微电网的频率调节能力,研究了多种分布式电源参与的孤岛微电网调频方法。在发电侧,设计了光伏参与一次调频策略,频率高于阈值时光伏开始减载,参与一次调频后光伏能够主动恢复至最大功率跟踪(maximum power point tracking,MPPT)模式下的功率。在负荷侧,充分利用负荷的电压特性,通过调整逆变器出口侧母线电压调整负荷所消耗的功率,使负荷侧能够主动参与孤岛微电网的频率调节,同时基于低阶系统频率响应(system frequency response,SFR)模型分析了各分布式电源一次调频参数对孤岛微电网频率的影响,以最大频率偏差量和母线电压为约束,提出了需求侧参与孤岛微电网频率协调控制策略。最后在RTDS仿真平台上搭建了微电网仿真模型,仿真结果验证了所提控制策略的有效性。

A large number of distributed generations are connected to microgrids through power electronic devices, which reduces the equivalent inertia of the system and makes the frequency problem of the island operation of the microgrid particularly prominent. In order to improve the frequency regulation ability of island microgrid, a frequency regulation method involving multiple distributed power sources is studied. On the generation side, the photovoltaic participating in the primary frequency regulation strategy is designed. When the frequency is higher than the threshold, the photovoltaic begins to reduce the load. After participating in the primary frequency regulation, the photovoltaic can actively restore the power in maximum power point tracking(MPPT) mode. On the load side, the voltage characteristics of the load are fully utilized to adjust the power consumed by the load by adjusting the bus voltage at the outlet side of the inverter, so that the load side can actively participate in the frequency regulation of the island microgrid. At the same time, based on the low order system frequency response(SFR) model, the influence of the primary frequency regulation parameters of distributed power sources on the frequency of island microgrid is analyzed, and the demand side participating in frequency coordination control strategy of island microgrid is proposed with the maximum frequency deviation and bus voltage as constraints. Finally, a microgrid simulation model is built on the RTDS simulation platform,and the simulation results verify the effectiveness of the proposed control strategy.