摘要
在三相不平衡的电网电压条件下,存在电压不平衡、频率偏移的现象,会引起电压正序分量的相位难以被检测,相位估计精度严重降低。为了解决这一问题,本文提出了一种针对电压不平衡条件下的相位估计方法。首先,分析不平衡电网电压对相位估计造成的影响,并建立不平衡电网电压的复变模型;然后,提出复变最小均方误差(LMS)的相位估计方法进行电压正序分量的相位检测,又针对电压频率变化的问题,设计了频率跟踪算法法对电压的同步频率进行校正;最后通过仿真和实验,证明了本文提出的方法能够在三相不平衡的电压条件下快速准确地估计正序分量的相位,并能有效地降低电网电压频率偏移对相位估计造成的影响。
Under the three phase unbalanced voltage condition, the existence of unbalanced vohage even variable frequency makes the phase detection of the positive sequence voltage more difficult and reduces the accuracy of phase estimation. To solve this problem, a phase estimation method is presented under the unbalanced voltage condition. Firstly, the impact on phase estimation caused by unbalanced voltage is analyzed, and the complex model of unbalanced grid voltage is built. Then, a phase estimation method is proposed based on the complex least mean squares（LMS） algorithm to detect the phase of positive sequence voltage. Considering the various fre- quency of voltage, a frequency tracking algorithm is designed to modify the synchronous frequency. At last, the results of simulation and experiment demonstrate that the proposed method can estimate the phase of positive sequence voltage rapidly and accurately, and the method can effectively reduce the impact on phase estimation caused with the frequency bias.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2016年第1期231-238,共8页
Chinese Journal of Scientific Instrument
基金
国家自然科学基金重点资助项目(61433004)
国家自然科学基金(51467017)项目资助
关键词
不平衡电压
相位估计
最小均方误差
unbalanced voltage
phase estimation
least mean squares （LMS）
