电力系统保护与控制
電力繫統保護與控製
전력계통보호여공제
POWER SYSTM PROTECTION AND CONTROL
2015年
10期
85-90
,共6页
DFT%数字锁相环%递推最小二乘法%椭圆拟合
DFT%數字鎖相環%遞推最小二乘法%橢圓擬閤
DFT%수자쇄상배%체추최소이승법%타원의합
DFT%digital phase-locked loop%recursive least square method%ellipse fitting
针对传统的DFT单相锁相环在电网频率发生变化时存在锁相性能变差问题，提出了一种考虑频率变化的基于DFT单相数字锁相环的椭圆拟合方法。采用带遗忘因子的递推最小二乘法进行椭圆拟合辨识出椭圆参数，再由锁相环产生正、余弦输出，实现了基于虚拟两相正交电压矢量的单相数字锁相环控制。通过Matlab对电网电压的频率波动、相位突变以及谐波注入等参数变化的影响进行了仿真。最后，通过实验结果验证了该方法的有效性，具有较好的稳态性能和动态特性。
針對傳統的DFT單相鎖相環在電網頻率髮生變化時存在鎖相性能變差問題，提齣瞭一種攷慮頻率變化的基于DFT單相數字鎖相環的橢圓擬閤方法。採用帶遺忘因子的遞推最小二乘法進行橢圓擬閤辨識齣橢圓參數，再由鎖相環產生正、餘絃輸齣，實現瞭基于虛擬兩相正交電壓矢量的單相數字鎖相環控製。通過Matlab對電網電壓的頻率波動、相位突變以及諧波註入等參數變化的影響進行瞭倣真。最後，通過實驗結果驗證瞭該方法的有效性，具有較好的穩態性能和動態特性。
침대전통적DFT단상쇄상배재전망빈솔발생변화시존재쇄상성능변차문제，제출료일충고필빈솔변화적기우DFT단상수자쇄상배적타원의합방법。채용대유망인자적체추최소이승법진행타원의합변식출타원삼수，재유쇄상배산생정、여현수출，실현료기우허의량상정교전압시량적단상수자쇄상배공제。통과Matlab대전망전압적빈솔파동、상위돌변이급해파주입등삼수변화적영향진행료방진。최후，통과실험결과험증료해방법적유효성，구유교호적은태성능화동태특성。
When the grid frequency is varied, the traditional single-phase Phase-locked Loop (PLL) using DFT becomes dissatisfactory. To solve the problems an approach is proposed where ellipse fitting algorithm is incorporated a single-phase Digital Phase-locked Loop (DPLL) based on DFT considering frequency variation. Recursive least square method with forgetting factor is adopted to fit and identify the ellipse parameters, and sine and cosine signals are generated and output by phase-locked loop, then a DPLL on the basis of two-phase orthogonal voltage vector for single-phase digital phase-locked loop is implemented. The influence of parameter variations of the grid voltage including frequency fluctuation, phase mutation and harmonic injection is simulated by MATLAB. Finally, the experimental results verify that the approach is feasible and has better steady-state performance and dynamic characteristics.
