A Method to Improve the Dynamic Performance of Moving Average Filter-Based PLL

Performance Evaluations of Four MAF-Based PLL Algorithms for Grid-Synchronization of Three-Phase Grid-Connected PWM Inverters and DGs

“…Therefore, the DMAF-PLL input signal v ' abc is free of dc offset. In [36], the aMAF block is designed to be frequencyadaptive using the rounding-down method N=round (mπ/ω 0 T s ), where m=2. Although this structure can effectively filter out the dc offset, the aMAF requires a time interval of 0.02 s to reach the steady-state condition.…”

“…Thus, substituting s=jω into (18) and performing a simple mathematical operation [36], it is possible to get:…”

“…In addition to the use of these new structures, a more general approach to improving the performance of a PLL is to combine them with filters [15]- [36], such as extended Kalman filters (EKFs) [15], space vector filters (SVFs) [16], notch filters [17], digital filters [18], complex-coefficient filters (CCF) [19], the delayed signal cancellation (DSC) block method [20]- [24], and MAF-based methods [25]- [36]. Among these filtering techniques, DSC and MAF show similar filtering characteristics.…”

“…This may be beneficial in terms of stability, but it degrades the dynamic performance of the PLL. To solve this problem, some advanced MAF-based PLL algorithms have been presented [27]- [36].…”

“…With a phase-lead compensator in the control loop, the dynamic response of the standard MAF-PLL can be effectively improved without deteriorating its disturbance rejection capabilities. A differential MAF-PLL (DMAF-PLL) was presented in [36]. With this approach, a special loop filter structure was used to eliminate the negative sequence 2 nd order harmonics in order to reduce the window length of the MAF and to significantly improve the dynamic performance of the PLL.…”