摘要
随着电力电子设备在电力系统中的不断渗透,基于电压源型变流器的柔性直流输电技术得到了广泛应用。目前柔性直流输电系统中换流站大多采用跟网型控制,与弱电网连接时可能导致频率稳定性问题。在跟网型控制的基础上提出了组网型虚拟同步机控制,该控制策略可以改善换流站在弱电网条件下的动态性能和频率支撑能力,提高系统稳定性。最后,在PSCAD/EMTDC仿真平台搭建了三端柔性直流输电系统的仿真模型,对比分析了两种控制策略的控制特点和性能。
With the continuous penetration of power electronics in power systems,the flexible DC transmission technology based on voltage-source converter has been widely used.Grid-following control is applied in most of the converter stations in present flexible DC transmission systems,which may lead to frequency stability problems when connected to weak grids.On the basis of the grid-following control,a grid-forming virtual synchronizer control is proposed.This control strategy can improve the dynamic performance and frequency support capability of the converter station under weak grid conditions and enhance the system stability.Finally,simulation using a model of three-terminal VSC-MTDC system in PSCAD/EMTDC was conducted.The control characteristics and performance of two strategies are compared and analyzed.
作者
魏力超
王晨轩
章泽磊
汪震
WEI Li-chao;WANG Chen-xuan;ZHANG Ze-lei;WANG Zhen(College of Electrical Engineering,Zhejiang University,Hangzhou 310027,China)
出处
《能源工程》
2022年第6期67-74,共8页
Energy Engineering
基金
国家自然科学基金资助项目(52077196)。
关键词
电压源型变流器
柔性直流输电
跟网型控制
组网型控制
频率稳定
虚拟同步发电机
voltage source converters
flexible DC transmission
grid-following control
grid-forming control
frequency stability
virtual synchronous generator
