柔性直流输电——适用于风电场的电力传输新技术

VSC HVDC—a New Technique Applicable to Power Transmission of Wind Farms

阐述了柔性直流输电基本原理和特点,以及在风电场并网运行中的应用。分析了柔性直流输电的拓扑结构,在此基础上建立了柔性直流输电系统的暂态数学模型,推导了电压源换流器控制量与被控量之间的对应关系,并据此设计了非线性解耦控制器,实现输送有功、无功功率的解耦控制。最后通过Simulink仿真模型的建立和对直流短路故障的分析,验证了所建立的仿真模型以及控制方式的正确性和合理性,为进一步研究柔性直流输电在风电场电力传输中的应用奠定了基础。

The basic principle and characteristic of VSC HVDC are introduced with its application in connecting wind farms to AC system.On the basis of analyzing the topology of VSC HVDC,a transient mathematical model of VSC HVDC system is established,accordingly determining the relationship between the control quantity and the controlled quantity of voltage source inverter VSC.A nonlinear decoupling controller is designed,achieving the decoupling control for the transmission of active and reactive power.At last,through setting up a Simulink model and analyzing the DC short-circuit fault,the correctness and rationality of the model and the control methods are verified.This study provides a theoretical basis for further research on VSC HVDC applied in power transmission of wind farms.