摘要
混合式多电平变流器(HMC)能够实现有功无功独立控制,在直流侧发生故障时,交流侧电流仍然可控,这对于构成直流电网有重要意义。文中研究了HMC的电压合成方法以及在静止同步补偿器(STATCOM)模式下和高压直流(HVDC)模式下的能量平衡原理。基于能量平衡的原理,提出了STATCOM模式下和HVDC模式下桥臂电容稳压控制方法,并提出了HVDC模式下桥臂电容稳压的具体实现方法。为了验证所提出的能量平衡原理及控制策略,根据仿真算例所提供的参数,搭建了端对端直流输电的PSCAD仿真模型,对HMC的启动充电、解锁、有功渐变和直流故障过程进行了仿真。仿真结果显示,HMC能够实现有功无功独立控制,能够隔离直流侧故障,所提出的能量平衡原理与控制方法能够实现桥臂电容的稳压控制。
As a very important characteristic for DC grid,the active and reactive power of a hybrid multilevel convertor(HMC) can be controlled independently,so the AC current is still controllable when there is a fault on the DC side.The AC voltage synchronous method and the energy balance principle of the static synchronous compensator (STATCOM) model and high voltage direct current (HVDC) model are studied.Based on the energy balance principle,the capacitor voltage stabilizing principle of the arm in the STATCOM model and HVDC model is put forward,and the capacitor voltage balance method is realized in detail.In order to verify the principle and the method of the capacitor voltage balance,a PSCAD model is developed according to the parameter of the simulation example.The processes each of charging,deblocking,active power changing and DC fault are simulated.Results of the simulation show that the active current and reactive current of the HMC can be controlled independently of each other with the DC side fault of the HMC isolated.The capacitor voltage balance principle and method proposed are also proved effective.
出处
《电力系统自动化》
EI
CSCD
北大核心
2015年第6期75-81 120,120,共8页
Automation of Electric Power Systems
基金
国家重点基础研究发展计划(973计划)资助项目(2012CB215200)~~
关键词
混合型多电平变流器
电压合成方法
能量平衡方程
稳压控制
高压直流输电
hybrid multilevel convertor(HMC)
voltage synchronous method
energy balance equation
voltage balancing control
high voltage direct current(HVDC)transmission
