摘要
由于现有的控制方法并网点处的直流和交流电压较低,控制效果不佳,为此基于VSC-HVDC,针对海上风电柔性直流输电系统并网控制方法展开研究。首先,根据VSC-HVDC系统结构建立海上风电柔性并网模型,在换流侧通过换流设备将交流电源转换为直流电,并将转换后的直流电能输送到直流输电线路上;然后,运用PI控制器根据电流偏差进行调节,调整换流器的输出电流与实际电流误差,限制幅度环节输出控制系统并网有功功率信息,实现内环网并网控制;最后,运用PI控制器对交流电进行跟踪,调整无功分量来改变交流电压,实现外环网并网控制,完成针对海上风电柔性直流输电系统并网控制方法的设计。实验结果表明,经该方法控制后,交流电压维持在约0.7 p.u.的水平,直流电压被成功地限制在0.5~1 p.u.以内,控制效果较好。
Due to the low DC and AC voltages at the grid connection points of existing control methods,the control effect is not satisfactory.Therefore,based on VSC-HVDC,research is conducted on the grid connection control method for offshore wind power flexible DC transmission systems.Firstly,a flexible grid connection model for offshore wind power is established based on the VSC-HVDC system structure.On the converter side,AC power is converted into DC power through converter equipment,and the converted DC power is transmitted to the DC transmission line.Then,the PI controller is used to adjust the output current of the converter according to the current deviation,adjust the error between the output current of the converter and the actual current,limit the amplitude link output control system\s grid connected active power information,and achieve internal loop grid connected control.Finally,the PI controller is used to track the AC power,adjust the reactive power component to change the AC voltage,achieve external loop grid connection control,and complete the design of the grid connection control method for the offshore wind power flexible DC transmission system.The experimental results show that after being controlled by the proposed method,the AC voltage is maintained at a level of about 0.7 p.u.,and the DC voltage is successfully limited to within 0.5~1 p.u.,with good control effect.
作者
傅春翔
叶真
朱军峰
Fu Chunxiang;Ye Zhen;Zhu Junfeng(PowerChina Huadong Engineering Corporation Limited,Hangzhou 310012,China;PowerChina Jiangsu Engineering Corporation Limited,Nanjing 210004,China)
出处
《机电工程技术》
2024年第10期225-227,261,共4页
Mechanical & Electrical Engineering Technology
关键词
VSC
HVDC
直流输电系统
并网控制
VSC
HVDC
direct current transmission system
grid-connected control
