海上风电场柔性直流送电并网控制研究
Control Strategy of Offshore Wind Farm Grid-Connection Through VSC-HVDC Transmission
石磊 1李晨晨 2田炜 1刘皓明2
作者信息
- 1. 国电南瑞科技股份有限公司,南京210061
- 2. 河海大学能源与电气学院,南京210098
- 折叠
摘要
针对大型风电场并网难题,分析了适合大型海上风电场送电并网方式.针对应用柔性直流方式送电并网方式,研究了柔性直流输电系统的数学模型和控制策略.应用变速恒频风机的海上风电场随风速变化而功率输出变化,海上换流站的控制需要保持电压频率稳定,根据其暂态方程提出了改进的直接电压控制来控制风电场母线电压频率.对电网侧换流站采用双闭环直接电流控制,控制直流电压和无功.基于PSCAD/EMTDC仿真平台搭建了海上风电场等效模型以及通过柔性直流送电系统仿真模型,对风电场风速变化、当地负荷切入以及无功指令变化进行了仿真,验证了控制策略的正确有效.
Abstract
In view of the problems of large-scale wind-farm grid connection,power transmission of grid-connection methods suitable for large offshore wind farms are analyzed.Based on the application of flexible HVDC (VSC-HVDC) transmission,mathematical model and control strategy of the transmission system are studied.Considering that the output power of variable-speed constant-frequency generator in offshore wind farm changes with wind speed,the control of offshore converter station requires to maintain stability of the voltage and frequency of wind farm bus,and therefore a modified direct voltage control method is proposed to control wind farm voltage and frequency according to the transient equation.Control of grid-side converter station is controlled by the double-loop direct current method in order to control the DC voltage and reactive power into the grid.Finally,based on PSCAD / EMTDC simulation platform,the offshore wind farm equivalent model and flexible HVDC power transmission system simulation model are built up,whereby the wind speed changes,the local cut-in and reactive power command changes are simulated,and the results verify the correctness and effectiveness of the proposed control strategy.
关键词
海上风电场/电压源型换流器/柔性直流输电/改进直接电压控制Key words
offshore wind farm/voltage source converter (VSC)/flexible HVDC/modified direct voltage control引用本文复制引用
基金项目
国家高技术研究发展计划资助(2013AA050601)
出版年
2014
NETL
NSTL
维普
万方数据