基于架空线的城市电网紧凑化输电增容方案

城市用电负荷的快速增加使得提高现有城市电网的输送能力迫在眉睫。为了解决这一问题,文中提出了一种城市电网紧凑化输电增容方案,送端和受端通过半桥模块化多电平换流器和极间电流开关连接交流系统原有3条输电线,基于设计的电流调制策略,计算了该方案的增容效果;同时分析了系统的稳态运行机理和启动过程,并设计了启动策略;最后,采用PSCAD/EMTDC从启动和稳态运行2个方面对该方案进行了仿真验证。研究结果表明,提出的紧凑化输电增容方案有较好的增容效果,能够稳定运行。

An Overhead Line Based Compact Transmission Scheme for Increasing Capacity in City Network

With the increase of urban electric load, improving the transmission capacity of existing city network has become extremely urgent. In order to solve this problem, a compact transmission scheme for increasing capacity is proposed, in which the sending and receiving ends connect to the original three transmission lines through half-bridge modular multilevel converters and inter-pole current transfer switches. Secondly, the current modulation strategy is modified to serve this topology and the ability of power increases is calculated. Thirdly, the steady-state operation mechanism and the system start-up procedure are analyzed, while the start-up strategy is designed. Finally, through the simulation based on PSCAD/EMTDC, the scheme is verified in terms of start-up and steady-state operation. The results show that the scheme proposed has good performance in increasing capacity while contributing to stable and reliable operation. This work is supported by State Grid Corporation of China (No. SGRI-DL-71-14-007).