一种新的分布式并网逆变器预同步算法

介绍了一种适用于并网逆变器预同步操作的电网电压基波分量递推DFT算法。该算法既能够可靠跟踪电网电压基波分量的相位、频率和幅值,又减少了计算量,保证了算法的实时性。在此基础上,该算法根据等角度间隔采样原理提出以递推DFT运算得到的基波相角为反馈调整采样间隔,实现了对电网电压频率的自适应跟踪,减少了频谱泄漏,提高了基波同步参数检测的精度。相对于传统的锁相环预同步方法,可以在谐波和零点漂移比较严重的情况下精确跟踪电网电压基波分量,从而减小逆变器并网操作对微电网以及逆变器本身的冲击。仿真结果表明了该算法的正确性。

A Novel Distributed Grid-connected Inverter Pre-synchronizing Algorithm

This paper presents a voltage fundamental wave recursive DFT algorith m applied in grid-connected inverter pre-synchronization. The algorithm not on ly be able to reliably track the voltage fundamental wave phase, frequency and a mplitude, but also reduces the calculating consumption to guarantee real-time a lgorithm. Based on the equal-angle interval sampling technique（EAISP）,the algor ithm can adjust the sampling interval according to the fundamental wave phase an gle feedback.So it can achieve adaptive voltage-frequency tracking to reduce th e spectral leakage and enhance the fundamental wave synchronization parameter de tection accuracy. With respect to the traditional phase-locked loop synchroniza tion method, the algorithm can precisely track the fundamental wave while harmon ics and grid voltage zero-offset are serious to reduce the impact on the micro-grid and the inverter itself when grid-connected operation. The simulation re sults show its validity and feasibility.