A method of frequency adaptive detecting for synchronous phase and instantaneous symmetrical components

• Published in: Zhejiang da xue xue bao. Journal of Zhejiang University. Sciences edition. Li xue ban Vol. 39; no. 3; pp. 297 - 302
• Main Authors: Chen, Hai-Rong, Liu, Zi-Jian, Tu, Qing-Rui
• Format: Journal Article
• Language: Chinese
• Published: Zhejiang University Press 01.05.2012
• Subjects: Circuits; Electric potential; Electronic equipment; Phase shift; Protection systems; Resonant frequencies; Synchronous; Voltage; 广义二阶积分器; 电力电子; 瞬时对称分量; 谐振频率; 锁相环
• ISSN: 1008-9497
• DOI: 10.3785/j.issn.1008-9497.2012.03.013

Under AC power system fault conditions, detecting synchronous phase and instantaneous symmetrical components quickly and accurately is an important part of the control and protection system of power electronic equipment. In this paper, the influence of negative sequence voltage components on the PLL's detecting performance is studied, a novel method based on frequency adaptive for detecting instantaneous symmetrical components is proposed. In this method, the theory of instantaneous symmetrical components in alpha - beta frame for detecting symmetrical components is adopted, the phase shift method of 90 degree based on second order generalized integrator is realized. q axis component of the fundamental positive voltage is used as input of the PLL and the angular frequency of PLL is used as resonant frequency of the circuit of phase shift. In this paper, implementation mechanism of the proposed method is analyzed. Block diagram of the detecting circuit is given and is also verified by experimental research. Ex