复杂电网工况下三相并网逆变器的锁频环技术

A frequency-locked loop technology of three phase grid-connected inverter under the complex power grid conditions

为解决复杂的电网工况下,传统的并网逆变器锁相环锁相精度不高、锁相速度慢等问题,提出了具有频率自适应滤波器、快速锁频和相序提取功能的双2阶广义积分器的锁频环,并做出伯德图,对滤波器的性能进行了分析;然后在电网电压幅值、频率、相位跳变下,对锁频环的基本性能(电网电压频率、相位、正负序提取)进行了测试,最后在谐波电压背景工况下,对其性能进一步仿真,验证了基于双2阶广义积分器的锁频环具有动态响应快、抗谐波能力较强、精度高、误差小等优点。

In allusion to solve the problem that the traditional phase locked loop of the three phase grid-connected in- verter is low accuracy and speed under the complex power grid conditions. Firstly, double second order generalized integrator frequency-locked-loop（DSOGI-FLL） is presented in this paper, which has the function modules of frequen- cy adaptive filter, fast frequency-locked and phase extraction, and the Bode diagrams are used to analyzed in depth. And then, the basic properties of DSOGI-FLL are tested, including the grid voltage frequency, phase and the positive and negative extraction. Finally, under the harmonic voltage background grid conditions, further simulations are done. The advantages of DSOGI-FLL are verified, in the aspects of fast dynamic response, strong ability of anti har- monic, high precision, small error, et al.