摘要
为了改进并网逆变器运行的可靠性,提出一种锁相环和改进虚拟电网磁链估算相结合的并网控制策略。该方法是在低通滤波器取代纯积分器的基础上,采用两个不同截止频率和比例系数的低通滤波器,构造磁链观测器,结合锁相环以提高虚拟磁链定向的准确度,有效抑制电网谐波干扰。分析了三相并网逆变器基于同步旋转坐标系的数学模型,建立锁相环和虚拟电网磁链相结合进行定向的矢量控制系统。仿真实验结果表明,逆变器可输出正弦度良好的逆变电流,提高了逆变器的工作稳定性,从而验证了该方案的可行性和正确性。
In order to improve the reliability of grid-connected inverter,a way of phase locked loop(PLL)and an improved control strategy was proposed to improve the virtual flux linkage estimation.The low-pass filter was used to replace the pure integrator,with two different cut-off frequencies and proportional coefficients,combined with the PLL to improve the accuracy of the virtual flux orientation,effectively suppressing the harmonic interference.This paper analyzed the mathematical model of three-phase grid-connected inverter based on synchronous rotating coordinate system,and established a PLL and a virtual power grid flux linkage for the vector control system.The simulation results show that the sinusoidal output current of the three-phase grid-connected inverter is good,and the stability of the inverter is improved,which verifies the feasibility and correctness of the scheme.
作者
郭茂松
王英
GUO Mao-song;WANG Ying(School of Electronics and Information Engineering, Dalian Jiaotong University, Dalian 11 6028, China)
出处
《电工电气》
2017年第5期10-14,33,共6页
Electrotechnics Electric
关键词
并网逆变器
磁链观测器
锁相环
低通滤波器
grid-connected inverter
flux observer
phase locked loop
low-pass filter
