摘要
模块化多电平矩阵变换器(modular multilevel matrix converter,M3C)用于海上风电低频输电系统(low frequency transmission system,LFTS)是具有广阔应用前景的新方案。M3C双频功率耦合对其9个桥臂直流侧电容电压的均衡控制及故障穿越带来挑战和困难。为此,提出基于桥臂双重低频环流注入法的新型M3C综合解耦控制策略。首先,对M3C工、低频侧进行数学建模并分析其功率运行范围。基于桥臂工、低频共模和差模回路的分析及桥臂功率平衡原则,提出实现工、低频侧输入及双重低频环流注入的M3C解耦控制策略。使用开环和闭环低频环流注入两种联合控制,在实现M3C各子变流器相间功率快速均衡的同时,确保工频侧输入电流的完全正序特性。通过带延时补偿的复矢量控制器,在静止坐标系统实现9个桥臂的完全独立控制,搭建35kV/11MW海上风电系统PSCAD模型,通过稳态、动态及暂态仿真全面验证所提综合控制策略的有效性和正确性。
The modular multilevel matrix converter(M3C)is a new scheme with broad application potential for the offshore wind power low frequency transmission system(LFTs).However,the dual frequency power coupling of M3C brings challenges and difficulties to balance control of DC capacitance voltage of nine bridge arms and fault ride through.Therefore,a new comprehensive control strategy for M3C based on the dual low frequency bridge arm circulation current injection method is proposed in this paper.Firstly,the mathematical models of M3C fundamental and low frequency sides are established and the power operation range of M3C is analyzed.Based on the analysis of common and differential mode circuits of fundamental and low frequency,and the power balance principle of bridge arms,the M3C decoupling control strategy of the input control of fundamental and low frequency side with dual low frequency circulating current injection are proposed.Two joint control methods of open-loop and closed-loop low frequency circulating current injection are adopted to realize rapid phase-to-phase power balance of M3C sub-converters and meanwhile ensure completely positive sequence characteristics of the input current of fundamental frequency side.Through complex vector controllers with delay compensation,complete independent control of nine bridge arms is achieved in the static coordinate system.A 35kV/11MW offshore wind power system is built in PSCAD to verify the effectiveness of the proposed control strategy through steady-state,dynamic and transient simulation.
作者
吴小丹
李建春
董云龙
朱海勇
陆立文
周前
WU Xiaodan;LI Jianchun;DONG Yunlong;ZHU Haiyong;LU Liwen;ZHOU Qian(NR Electric Co.,Ltd.,Nanjing 211102,Jiangsu Province,China;Jiangsu Electric Power Co.,Ltd.Research Institute,Nanjing 211103,Jiangsu Province,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2023年第8期3177-3190,共14页
Proceedings of the CSEE
基金
国家电网公司总部科技项目(4000-202218073A-1-1-ZN)。
关键词
模块化多电平矩阵变换器
低频输电系统
海上风电
双重低频环流
桥臂电流控制
复矢量控制器
modular multilevel matrix converter
low frequency transmission system
offshore wind power
double low frequency circulating current
bridge arm current control
complex vector controller
