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The cascaded delayed signal cancellation (CDSC) based PLL in dq rotate frame ( dq CDSC-PLL) can totally eliminate the disturbances of phase error. However, its open-loop bandwidth is significantly affected after incorporating CDSC into the PLL structure, so the transient response performance of three dq CDSC-PLLs are deteriorated. This paper proposes an improved dq CDSC-PLL by cascading a digital filter based phase-lead compensator into CDSC-based PLL to improve the dynamic response without sacrificing the stability. The filter shows flat gain in the passband, which can compensate the phase delay induced by CDSC and simultaneously maintain the attenuation of the notch point. The improved dq CDSC-PLLs significantly increases the open-loop bandwidth and enhances the dynamic performance. Besides, in order to further minimize the undesirable steady-state error, the frequency adaptive control was adopted without using any additional circuits. In order to verify the effectiveness of the proposed method, the simulation based on Matlab/Simulink is carried out for various conditions. Furthermore, experimental results for typical scenarios are provided, which highlight the advantage of the improved dq CDSC-PLL in terms of the dynamic performance. [ABSTRACT FROM AUTHOR]

• The proposed method is suitable for more electric aircraft grids. • The proposed method has fast dynamics. • The structure of the proposed method is simple. Different from utility power systems, the grids of more electric aircraft (MEA) are frequency-variable, and the frequency change range is from 360 Hz to 800 Hz. Most grid synchronization methods are designed for constant-frequency grids whose frequency varies in a small range around 50 Hz or 60 Hz. Therefore, the dynamic performance of these methods decreases considerably in MEA grids. In addition, the frequency in MEA is higher than that in utility power systems. Grid voltage parameters are thus required to exhibit a fast dynamic response. To resolve this problem, this paper proposes an algebraic method to estimate the positive- and negative-sequence components (PNSC) of grid voltage accurately. By analyzing the relationship between grid voltage and its time delay signals, the linear regression model is established. Then, grid frequency, PNSC are obtained with an algebraic method. The proposed method relies on algebraic operations only and thus exhibits a fast dynamic response. Experiment results verify the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]