电网不平衡状态下风电机组运行控制中电压同步信号的检测

大型风电机组所联电网并不理想,时有故障发生,给并网风电机组运行控制提出更高要求.为了增强风电机组可靠运行能力,必须对各种故障下电网的频率、相角和幅值进行准确、快速地检测,以便控制系统及时采取应对措施.作为风电机组不对称运行的前期研究,本文在充分研究现有锁相环(PLL)技术的基础上,提出了一种能够同时跟踪电网电压正、负序分量的新型双dq PLL方法,并通过仿真和实验验证了其优越的性能.该方法对电网不对称状态具有较强的检测能力,能为电网不对称故障下风电机组运行控制提供实施依据.

Detection of Voltage Synchronization Signals for a Wind Energy Generation System Unbalanced Grid Conditions

Because the connected grid for the high-power wind energy generation systems (WEGSs) is not idealized, malfunction will often happens, which will raise more strict demands on the operation of grid-connected WEGSs. In order to improve the operation stability of the high-power WEGSs, some important information of the unbalanced grid must be investigated. For the sake of detecting the amplitude, phase and frequency of the grid voltage under unbalanced conditions, a new kind of phase-locked loop (PLL), the dual-dq PLL, is proposed and studied in the paper. This dual-dq PLL is proved to possess the advantage of detecting the positive and negative sequence components of the grid voltage simultaneously both by simulation and experiment study. As a preparative research fruit, the suggested dual-dq PLL scheme is capable of offering the basis for the controlling of WEGSs under unbalanced grid conditions.