特高压柔性直流换流站运行策略研究

Research on Operation Strategy of UHV Flexible DC Converter Station

为实现换流站的协调控制,采用了分层控制,分别为系统调度层控制、柔性直流换流站层控制以及晶闸管器件层控制。其中,柔性直流换流站层接收系统调度层的控制指令,控制换流站有功功率跟踪、无功功率跟踪、过电流抑制以及过电压抑制等。柔性直流换流站层控制策略对电能质量的影响较大,分析了由模块化多电平变换器构成的换流器的数学模型,采用功率外环控制器与电流内环控制器构成的双环控制。在MATLAB/Simulink中搭建了仿真模型,仿真结果验证了控制策略的有效性。

In order to realize the coordination and interconnection control of the converter station,the layered control system is adopted,namely the system scheduling layer,the flexible DC converter station layer and the converter valve layer.The control targets of the flexible DC converter layer is from the system scheduling layer,and the control targets are active power,reactive power tracking,overcurrent suppression,overvoltage suppression,etc.The control operating performance of flexible DC converter layer has a large influence on power quality.Based on the mathematics model of DC converter,which is made of the modular multilevel converter,a double loop control of outer loop controller and inner loop controller is adopted.The simulation model is built in MATLAB/simulink,and the simulation results verify the effectiveness of the control strategy.