多端柔性直流输电系统直流电压自适应下垂控制策略研究  

DC Voltage Adaptive Droop Control of Multi-terminal HVDC Systems

作　　者：罗永捷 李耀华[1] 王平[1] 李子欣[1] 高范强[1] 徐飞[1] 

机构地区：[1]中国科学院电力电子与电气驱动重点实验室(中国科学院电工研究所),北京市海淀区100190

出　　处：《中国电机工程学报》2016年第10期2588-2599,共12页Proceedings of the CSEE

基　　金：国家重点基础研究发展计划项目(973项目)(2012CB215200)~~

摘　　要：直流电压控制是多端柔性直流输电(voltage sourced converter based multi-terminal high voltage direct current transmission,VSC-MTDC)系统稳定运行的重要因素之一。下垂控制策略无需通讯、可靠性较高,但存在直流电压质量较差、功率分配不独立、参数设计困难等问题。首先,研究MTDC系统中下垂控制参数对直流电压与电流(功率)的影响机理。接着,分析应用于MTDC系统的下垂控制策略的约束条件,研究满足MTDC系统功率平衡和直流电压稳定的V-I(V-P)下垂特性曲线。在此基础上,提出一种改进的自适应下垂控制策略,通过引入功率影响因子实现下垂系数的闭环控制,优化不同工况下的系统运行特性。该控制策略能够减小MTDC系统的直流电压偏差,简化控制器参数设计,同时不依赖于上层控制系统与换流站之间的高速通讯,有利于提高系统可靠性和稳定性。算例分析和仿真结果验证了所提出方法的正确性和有效性。DC voltage control is of importance for the stable operation of voltage sourced converter based multi-terminal high voltage direct current（VSC-MTDC） transmission systems.First,the effects of the droop characteristic on DC voltages and currents of MTDC system were studied and the mechanism of the effects was explained.Then,the constraint conditions on the droop control strategy and the V-P or V-I characteristic that makes the power balance and voltage stability achieved in MTDC were analyzed.An improved adaptive droop control of DC voltage was proposed to improve the DC voltage quality and simplify the design of control systems.The proposed adaptive droop control strategy introduces the power influence factor and realizes the closed-loop control of the droop coefficient during transmitted power variation.Simulation results verify the feasibility and effectiveness of the control strategy.

关 键 词：多端柔性直流输电 直流电压 自适应下垂控制 功率影响因子 模块化多电平换流器 

分 类 号：TM721[电气工程—电力系统及自动化]