基于三相电压空间矢量的开环锁相方法  

An Open-Loop Phase-Locked Method Based on Three-Phase Voltage Space Vector

作　　者：余攀 盛万兴 钟佩军 孙建军[1] 潘静 Yu Pan;Sheng Wanxing;Zhong Peijun;Sun Jianjun;Pan Jing(School of Electrical Engineering and Automation Wuhan University,Wuhan 430072 China;China Electric Power Research Institute,Beijing 100192 China;State Grid Anhui Electric Power Co.Ltd,Hefei 230061 China)

机构地区：[1]武汉大学电气与自动化学院,武汉430072 [2]中国电力科学研究院有限公司,北京100192 [3]国网安徽省电力有限公司,合肥230061

出　　处：《电工技术学报》2020年第16期3460-3469,共10页Transactions of China Electrotechnical Society

基　　金：国家重点研发计划(2016YFB0900400);智能电网联合基金(U1866601)资助项目。

摘　　要：准确快速地获取电网基波正序电压的相位信息,是实现并网变流器精确控制的前提。然而当电网出现异常时,传统的闭环锁相方法动态响应时间较长,难以满足快速响应的控制需求。为此提出一种基于三相电压空间矢量的开环锁相方法,该方法首先通过过零检测得到电网的频率;然后利用离散傅里叶级数滤除电网电压中的谐波与噪声,并得到与基波电压相互正交的电压信号;在此基础上采用对称分量法提取电压正序分量;最后根据电压空间矢量计算基波正序电压的实时相位。同时为了应对电网电压突变时过零检测出现的异常频率,提出一种改进的过零检测算法,可有效应对电网电压异常时的频率检测。所提出的锁相方法无需参数设计且结构简单、响应速度快,在异常电网环境下具有较强的鲁棒性,仿真和实验结果验证了该方法的有效性和可行性。Accurate and fast phase acquisition for fundamental positive-sequence components is the premise for precise control of grid-connected converters.However,when the power grid is abnormal,the traditional closed-loop phase-locked method has a slow dynamic response,which is difficult to meet the control requirements of fast response.For this reason,an open-loop phase-locked method based on three-phase voltage space vector is proposed.In the method,the frequency of power grid is obtained by zero-crossing detection,the harmonic and noise in the grid voltage are filtered by discrete Fourier series,and the voltage signal orthogonal to the fundamental voltage is obtained.On this basis,the symmetric component method is used to extract the positive sequence component of voltage.Finally,the phase of fundamental positive-sequence voltage is calculated based on voltage space vector.At the same time,an improved zero-crossing detection algorithm is proposed to deal with the abnormal frequency when the voltage of power grid changes abruptly,which can effectively detect the frequency of abnormal grid voltage.The proposed phase-locked method does not require parameter design,and has a simple structure and fast response speed.It has strong robustness in abnormal grid environment. The simulation and experimental results verify the effectiveness and feasibility of theproposed method.

关 键 词：开环锁相 空间矢量 离散傅里叶级数 对称分量法 过零检测 

分 类 号：TM46[电气工程—电器]