A Modified SRF-PLL for Phase and Frequency Measurement of Single-Phase Systems


In this work, a single phase phase-locked-loop (PLL) that uses a low-pass notch filter is proposed. The new PLL was derived from the synchronous reference frame PLL (SRF-PLL) in which the dq axis components were generated using the αβ reference signals. The single-phase grid voltage was used as the α component, whereas the β component was derived by delaying the grid voltage by 90° in phase. The dynamics of the proposed PLL were compared to those of the SRF-PLL. The frequency measurement using the new PLL showed better performance over the SRF-PLL and a second-order generalized integrator (SOGI) PLL. The proposed PLL displayed better performance under both variable frequency and distorted grid voltage conditions. Experimental results were used to validate the dynamics obtained from the simulation results. The proposed method adds very little complexity to the conventional SRF-PLL.

Meeting Name

8th Annual IEEE Energy Conversion Congress and Exposition (2016: Sep. 18-22, Milwaukee, WI)


Electrical and Computer Engineering

Research Center/Lab(s)

Intelligent Systems Center

Keywords and Phrases

Energy Conversion; Notch Filters; Distorted Grid Voltage; Frequency Measurements; Low-Pass Notch Filter; Phase Locked Loop (PLL); Secondorder Generalized Integrator (SOGI); Single Phase System; Synchronous Reference Frame; Variable Frequencies; Phase Locked Loops; Frequency Measurement; Voltage Measurement; Mathematical Model; Harmonic Analysis; Phase Measurement; Transfer Functions; Power System Measurement; Low-Pass Filters; Notch Filters; Phase Measurement; Power Grids; Power Harmonic Filters

International Standard Book Number (ISBN)

978-1509007370; 978-1509007387

Document Type

Article - Conference proceedings

Document Version


File Type





© 2016 Institute of Electrical and Electronics Engineers (IEEE), All rights reserved.

Publication Date

01 Sep 2016