一种多风电场多端柔性直流输电的模拟电源控制

基于电压源换流器(VSC)的多端直流输电(VSC-MTDC)是风电场群接入电网的一种优选方式。对于多个风电场由VSC-MTDC并网,提出了一种新的VSC-MTDC模拟电源控制并应用了一种VSC-MTDC星形拓扑结构。该方法将VSC-MTDC的风电场侧换流器交流母线控制为定电压幅值、频率和相角的电源点,对风电有功实现了随动控制。拓扑结构中风电场侧换流器共用一条直流通道输电并将其中一侧换流器直流母线用作汇流点。一种新的直接电流矢量控制应用于电网侧换流器来控制直流电压。3个风电场4端VSC-MTDC的PSCAD/EMTDC仿真验证了拓扑结构可行且控制方法正确有效。

A Power-Source Simulating Control of VSC-MTDC With Multiple Wind Farms Integrated

The voltage source converter (VSC) based multi-terminal HVDC (VSC-MTDC) is a superior scheme for the connection of wind farm groups. In this paper a power-source simulating control method is proposed and a star topology is used for VSC-MTDC connected multiple wind farms. The ac bus of the wind farm side VSC is modulated to a source node with constant amplitude, constant frequency and constant phase angle, thus the follow-up control of wind power is achieved. In the star topology, the wind farm side VSCs share a common dc transmission corridor and a dc bus of the VSCs is assigned as confluence node. A new direct current vector control method is applied in the grid side VSC to regulate the dc voltage to the reference value. The simulation of a three-wind-farm four-terminal VSC-MTDC system in PSCAD/EMTDC verifies the validation of the proposed control strategy and the feasibility of the topology.