孤岛微电网双站并联运行功率控制策略

Power control strategy for parallel operation of isolated island microgrid with two stations

提出了一种基于储能SOC偏差控制场站并联运行新方法,目的是减小双站储能充放电时SOC差值,以达到不同起始SOC在某一时刻充放电曲线一致,旨在改善香港地区某岛含分布式电源配电网的电压质量和分布式储能SOC一致性。该微电网由A站和B站组成,其中A站采用V/F模式,确保输出电压具有相同的幅值和频率,而B站采用P/Q控制,根据最新采集的运行数据,由智能场站控制器内嵌逻辑算法计算得到功率设定参考值,并自动发送给B站PCS的P和Q设定值。在P/Q控制模式下,储能电池输出无功功率以支撑无功功率,减少连接线上的无功功率和电流,降低连接线电压偏差,且在储能SOC极限状态下,可使用过频减负荷保证系统稳定运行。该方法能够使整个并联系统在任何情况下实现最优运行成本和最高安全性,并满足储能SOC均衡原则。通过在Matlab仿真平台以及硬件实验平台上进行仿真和实验验证,证明了所提出策略的有效性和可靠性,该方法易于实现A、B站功率的合理分配。

a new method for parallel operation of stations is proposed based on the control of energy storage SOC(State of Charge)deviation,aimed at reducing the SOC difference during the charging and discharging of dual stations,to achieve consistency in the charging and discharging curves at a certain moment from different starting SOCs.The objective is to improve the voltage quality and the consistency of distributed energy storage SOC within a distribution network containing distributed power sources in a certain island of Hong Kong region.The microgrid consists of Station A and Station B,where Station A operates in V/F mode to ensure the output voltage has the same amplitude and frequency,while Station B employs P/Q control.Based on the most recently collected operational data,the power setting reference value is calculated by an embedded logic algorithm within the intelligent station controller and automatically sends the P and Q setting values to the PCS of Station B.In the P/Q control mode,the energy storage battery outputs reactive power to support reactive power,reducing the reactive power and current on the connecting lines and lowering the voltage deviation on the connecting lines.Moreover,under the extreme SOC states of energy storage,over-frequency load shedding can be used to ensure the stable operation of the system.This method can achieve optimal operational costs and the highest safety under any circumstances while satisfying the principle of energy storage SOC equilibrium.The effectiveness and reliability of the proposed strategy have been proven through simulations and experimental validations conducted on the Matlab simulation platform and a hardware experimental platform,demonstrating the method’s ease in achieving a rational power distribution between Stations A and B.