基于二阶广义积分器的单相并网系统锁相技术的研究

由于电网电压通常受到扰动和谐波的影响,因此在并网变换器的同步应用中,并网电流和电网存在相位差,会对电网产生冲击和污染。实践经验表明基于某种正交信号发生器(QSG)的锁相环(PLL)具有更好的性能。文章采用基于二阶广义积分器(SOGI)的正交信号发生器,并加以改进,在无需使用三角函数的情况下,设计一个简单的控制环将SOGI谐振器中心频率自适应调节为输入频率,并去除PLL模块,构造了新型的锁频环(FLL)结构。仿真结果表明,该方法不仅易于设计和实现,同时其性能优异,频率和相角的检测速度较快,且不含有稳态振荡,验证了方案的可行性和优越性。

Research on SOGI for Phase Lock Technique of the Single-phase Grid-connected System

For the grid voltage is usually affected by disturbance and harmonic, so in the synchronous application of grid-connected converter, there is a phase difference between grid-connected current and grid voltage, which will have impact and pollution to the power grid.The practical experience shows that some phase locked loop(PLL) based quadrature signal generator( QSG) has better performance.This paper adopts the second-order general integrator( SO-GI) that is improved, and frequency of SOGI automatically tracks the input frequency through a simple control loop instead of trigonometric function.Finally, this scheme constructs new-style structure of the frequency locked loop with PLL module.This scheme is easy to design and implement, simulation results show its excellent performance, and the frequency and angle can be detected rapidly and do not contain a steady oscillation, the feasibility and the superiority of the scheme are verified.