解耦多同步参考坐标系电网电压同步信号检测方法

在新能源发电并网中,并网变换器需根据电网运行状态实施相应的控制以保证其安全可靠运行。需要对电网电压的频率和相位实现快速准确的检测,同时还需要为变流器的并网运行提取出正负序分量。本文针对解耦双同步参考坐标系锁相环在谐波情况下频率检测结果和同步效果差的问题,提出了一种解耦多同步参考坐标系电网电压同步信号检测方法。该方法通过正负序dq轴系以及低次谐波的dq轴系分解,实现了多轴系dq分量的解耦,可以在电网电压不对称和含有谐波分量的情况下,快速提取出电网电压的频率和相位信息,同时还可得到正负序分量的dq轴变换结果。实验结果表明提出的方法在电网电压不对称、频率变化和含有多次谐波情况下均具有很好的同步效果。

A Grid Voltage Synchronization Method Based on Decoupled Multiple Synchronous Reference Frame

In renewable energy integration filed,the grid voltage synchronization signal should be fed back to the grid-tied converter for reliable operation.The frequency and phase information of the grid voltage,and the dq components of the positive and negative sequence are also needed for the converter control.Due to the limited performance of frequency detection and fundamental component separation of the decoupled double synchronous reference frame phase lock loop(DDSRF-PLL) under harmonic condition,a grid voltage synchronization method based on decoupled multiple synchronous reference frame PLL(DMSRF-PLL) is proposed.This DMSRF-PLL employs the positive,negative sequence and low-order harmonics dq transformation and their decoupling to achieve high speed and high performance output under asymmetric and harmonic condition for frequency,phase pick up positive and negative sequence dq components.The measured results verified the performance of the proposed DMSRF-PLL method under complex grid condition.