An Improved Large-Signal Model for Accurate Transient Analysis of DDV-PLL Under Large Grid Disturbance Conditions

Abstract

To against the variation of grid voltage amplitude, directly dividing the d-axis voltage phase-locked loop (DDV-PLL) is widely used due to its simple structure. However, conventional DDV-PLL models fail to describe the transient behavior under large grid disturbance conditions accurately. Thus, a more accurate large-signal model for DDV-PLL is proposed, which fully considers the effects of grid voltage phase, frequency, and amplitude disturbances. Then, a domain of attraction (DA) estimation method based on the time-domain Maclaurin series expansion is proposed as a quantitative criterion for transient behavior and the DDV-PLL d-axis filtering parameter design guideline. Theoretical analysis and experimental results validate the high accuracy of the proposed scheme and the effectiveness of the proposed design guideline under large grid disturbance conditions.