基于单相光伏逆变器的新型频率自适应复合SOGI锁相技术

A New Frequency Adaptive Multi-SOGI Phase Lock Technology Based on Single-phase PV Inverter

锁相环技术对实现大规模新能源系统的并网运行起着重要作用。文章基于对双重SOGI的研究,提出了一种新型频率自适应复合SOGI结构,解决了传统二阶广义积分器信号处理能力差和跟踪性能差的缺陷,提高了SOGI的自适应能力和抗扰动能力。与常规锁相技术相比,此结构在电网电压畸变严重和频率波动的情况下,依然具有精确锁相的优越性能。经过仿真和实验进行系列对比,结果验证了提出的新型结构具有良好的信号处理能力和跟踪性能。

Phase locked loop technology plays an important role in the realization of large-scale integration of new energy system. Under non-ideal grid environment, the traditional generalized integrator has poor signal processing ability and tracking performance. Although the multi-SOGI structure has better filtering effect especially in low frequency, while the input signal contains de component, the filtering effect is not satisfactory and the output waveform can be affected by the frequency fluctuation of the power grid. In order to address the issues of multi-SOGI, this paper proposes a novel frequency adaptive multi- SOGI structure which consists of the frequency locked loop and an improved multi-SOGI. The improved multi-SOGI can not only effectively reduce the content of DC component, but also can automatically tracking grid voltage and realize frequency adaptive. On the foundation of novel frequency adaptive multi-SOGI structure, a novel PLL structure is presented to improve the collapse phenomenon in phase locking of traditional PLL when the grid voltage is distorted, which has the precise phase-locked performance even under distorted voltage and frequency fluctuated conditions. Simulation and experiment results verify the signal processing ability and tracking performance of the proposed novel structure.