基于改进基频调制电流源换流器的高压直流输电系统  

Enhanced Fundamental Frequency Modulation Based Current Source Converter for HVDC Transmission

作　　者：赵成勇 冯定腾 熊小玲 李晓博 姚辰昊 ZHAO Chengyong;FENG Dingteng;XIONG Xiaoling;LI Xiaobo;YAO Chenhao(State Key Laboratory of Alternate Electrical Power System With Renewable Energy Sources(North China Electric Power University),Changping District,Beijing 102206,China)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市昌平区102206

出　　处：《中国电机工程学报》2024年第19期7726-7738,I0020,共14页PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING

基　　金：国家自然科学基金联合基金项目(U23B20119)。

摘　　要：主动换相型电流源换流器(current source converter,CSC)是一种新型的电流源换流器,其具有功率密度高,控制灵活,且无换相失败风险等优点,在直流输电领域具有广阔的应用前景。采用脉冲宽度调制的CSC存在直流电压波动大,开关损耗高等问题,不适用于直流输电场景。基频调制的CSC虽然缓解了直流电压波动,但是其仅有一个控制自由度,无法实现有功无功独立控制。针对上述问题,在基频调制CSC的基础上,提出一种适用于高压直流输电的改进型基频调制电流源换流器。首先分析改进基频调制原理和换流器交直流侧谐波特性,并设计直流滤波器;然后,建立系统的数学模型,并提出相应的系统功率控制策略;同时考虑到系统需要向无源网络供电的情况,提出一种无源网络供电控制策略。最后在PSCAD/EMTDC中搭建仿真模型,验证所提调制方法和控制策略的正确性和有效性。Current source converter(CSC)is a new type of current source converter,which has the advantages of high power density,flexible control,and no commutation failure risk,and it also has broad application prospects in the field of DC transmission.CSCs using pulse width modulation have problems such as large DC voltage fluctuations and high switching losses,and are not suitable for DC transmission scenarios.Although the CSC of fundamental frequency modulation alleviates DC voltage fluctuation,it only has one degree of control freedom,and cannot realize active and reactive independent control.In view of the above problems,this paper proposes an improved fundamental frequency modulation current source converter suitable for high-voltage DC transmission on the basis of fundamental frequency modulation.First,the principle of improved fundamental frequency modulation and the harmonic characteristics of the AC and DC side of the converter are analyzed,and the DC filter is designed.Then,the mathematical model of the system is established,and the corresponding system power control strategy is proposed.Finally,a simulation model is built in PSCAD/EMTDC to verify the correctness and effectiveness of the proposed modulation method and control strategy.

关 键 词：高压直流输电 电流源换流器 改进基频调制方法 功率控制策略 

分 类 号：TM72[电气工程—电力系统及自动化]