混合式潮流控制器关键参数设计与控制策略研究

Key Parameter Design and Control Strategy Research of Hybrid Power Flow Controller

随着分布式光伏等新能源接入电网的规模快速增长,给新能源电力汇聚、疏散、消纳和电网潮流优化控制带来严峻挑战。基于电力电子技术的柔性交流输电系统装置可有效提升输电网络的传输容量,由大容量Sen变压器(sen transformer,ST)和小容量统一潮流控制器(unified power flow controller,UPFC)组成的混合式潮流控制器(hybrid unified power flow controller,HPFC)在实现潮流连续调节的基础上,能够有效提升装置的经济性,具有很好的应用前景。为了确保HPFC调节潮流的准确性和可靠性,给出了HPFC容量分配的一般性方法及其主电路参数确定方法;为解决ST机械有载分接开关和UPFC电力电子开关二者响应速度的协调问题,提出了一种基于预测电流控制的潮流控制策略,并在Simulink中搭建220 kV双回线路及三机九节点系统进行仿真。仿真结果验证了HPFC容量分配方法正确有效,且预测电流控制策略能够合理计算抽头位置,减缓过渡电流对HPFC控制系统的冲击,使系统功率快速调节至目标值。

With the rapid growth of the scale of distributed photovoltaic and other new energy connected to the grid,it brings severe challenges to the new energy power convergence,evacuation,consumption and power grid flow optimization control.The flexible AC transmission system device based on power electronics technology can effectively improve the transmission capacity of the transmission network.The hybrid unified power flow controller composed of high-capacity Sen transformer and small-capacity unified power flow controller can effectively improve the economy of the device on the basis of realizing the continuous regulation of power flow,and has a good application prospect.In order to ensure the accuracy and reliability of HPFC power flow regulation,we gave the capacity allocation method of HPFC and the determination method of main circuit parameters.In order to solve the problem of coordination of response speed between ST mechanical on-load tap changer and UPFC power electronic switch,we proposed a power flow control strategy based on predictive current control,and built the 220 kV double-circuit circuit and three-machine nine-node system in Simulink for simulation.The simulation results show that the HPFC capacity allocation method is correct and effective,and the predicted current control strategy can reasonably calculate the tap position,slow down the impact of transition current on the HPFC control system,and make the system power quickly adjust to the target value.