摘要
海上风力发电与多端直流输电(MTDC)相结合是未来风力发电及其电能传输的发展方向之一。首先提出了应用于海上输电的四端直流输电系统的拓扑结构,并根据多端直流输电系统的特点,对直流输电系统的网侧逆变器采用直流电压下垂控制,不仅可以控制多端直流输电系统的电压稳定,而且灵活地对电网进行风电功率的传输。系统故障运行时,为避免对各换流器与风场间快速通信的要求,引入频率信号,将MTDC直流电压反映的功率不平衡量转变为频率的形式,来协调各风场减少风机出力以保持多端直流输电系统的电压稳定,实现系统可靠运行。最后基于Matlab/Simulink的仿真平台搭建了四端直流输电系统,验证不同运行状态下MTDC协调控制策略的有效性,结果表明多端直流系统在大扰动情况下能够保持系统安全稳定运行。
Multi-terminal HVDC transmission （MTDC） for the connection of large offshore wind farms to the terrestrial grid is the future development direction of wind power generation and power transmission. The voltage-current charac-teristics of the voltage source converters are analyzed. According to the characteristics of the multi-terminal HVDC, to control the DC voltage and coordinate the power sharing to the terrestrial grids, droop control scheme is designed in grid side converters. During abnormal operation, wind farm side converters take over the DC voltage control and coordinate the power reduction between wind farms, The control system introduced the frequency signal to remove the requirement for fast communication between the converters and achieved automatic coordination. The dynamic performance of the MTDC with the control system is tested through simulations using Matlab/Simulink. The simulation results verify the correctness of the proposed control strategy.
出处
《华北电力大学学报（自然科学版）》
CAS
北大核心
2013年第5期42-47,共6页
Journal of North China Electric Power University：Natural Science Edition
基金
中央高校基金资助项目(13MS74)
