摘要
柔性低频输电因其在中远海风电送出场景下具备较优的送出经济性而受到越来越多的关注。现有的低频输电风电系统采用恒压恒频的交流电传输电能,是低频输电和变速恒频风电技术的简单组合,这种组合易于工程实现,但没有充分考虑电压变换自由度这一关键因素。文中提出一种基于柔性低频输电风电系统的变电压运行控制方法,通过动态调整输电电压以适应不同风速下的发电要求。在这种运行方式下,提出一种与之匹配的风电机组动态最小直流母线电压控制方法,并形成一种无DC/DC变流器的宽范围机组直流母线电压频率支撑技术。进一步,就变电压运行方式的暂态过调制问题和损耗影响开展了分析,论证了无过调制风险和总损耗不增反降的原因。最后,通过仿真验证了所提控制方法的可行性及其在系统损耗、故障暂态电流、电网频率支撑方面的优越性。
Flexible low-frequency transmission has attracted more and more attention due to its superior transmission economy in the transmission scenario of medium-and far-offshore wind power.The existing wind power system with low-frequency transmission adopts constant-voltage and constant-frequency AC current to transmit electric power,which is a simple combination of low-frequency transmission and variable-speed constant-frequency wind power technology.This combination is easy to implement in engineering,but the key factor of the freedom degree of voltage conversion has not been fully considered.In this paper,a variable-voltage operation control method for the wind power system with flexible low-frequency transmission is proposed,which dynamically adjusts the transmission voltage to meet the power generation requirements with different wind speeds.In this operation mode,a matching dynamic minimum DC bus voltage control method for wind turbines is proposed,and a wide-range DC bus voltage frequency support technology is formed for units without DC/DC converters.Furthermore,the influence of variable-voltage operation mode on transient overmodulation problems and power loss is analyzed,and the reason why overmodulation will not occur and the reasons for the decreasing total loss are demonstrated.Finally,the feasibility and the superiority of the proposed control method in terms of system loss,fault transient current and grid frequency support are verified by simulation.
作者
贾锋
王麒铭
张雅君
符杨
杨心刚
章旭
袁宁谦
JIA Feng;WANG Qiming;ZHANG Yajun;FU Yang;YANG Xingang;ZHANG Xu;YUAN Ningqian(Engineering Research Center of Offshore Wind Technology,Ministry of Education(Shanghai University of Electric Power),Shanghai 200090,China;College of Electrical Engineering,Shanghai University of Electric Power,Shanghai 200090,China;Electric Power Research Institute of State Grid Shanghai Municipal Electric Power Company,Shanghai 200437,China)
出处
《电力系统自动化》
EI
CSCD
北大核心
2024年第21期38-48,共11页
Automation of Electric Power Systems
基金
国家重点研发计划资助项目(2021YFB2401100)
上海市科技创新行动计划项目(22dz1206100)
国网上海市电力公司科技计划项目(52094022003Q)。
关键词
海上风电
低频输电
风电机组
功率损耗
频率支撑
超级电容
offshore wind power
low-frequency transmission
wind turbine
power loss
frequency support
supercapacitor
