A new fast peak detector for single or three-phase unsymmetrical voltage sags

In this paper, a new fast peak detector for single or three-phase unsymmetrical voltage sags is proposed. The proposed detector is modified from a single-phase digital phase-locked loop based on a d-q transformation using an all-pass filter (APF). The all pass filter generates a virtual phase with 90° phase delay but the virtual phase cannot reflect a sudden change of the grid voltage in the moment of voltage sag, which causes a resulted peak value to be significantly distorted and settle down slowly. Specially, a settling time of the peak value is too long when voltage sag occurs around zero crossing such as phase 0° and 180°. This paper describes operating principle of the APF problem and proposes a modified all-pass filter (MAPF) to mitigate the inherent APF problem. In addition, a new fast peak detector employing the MAPF is proposed and the detector can calculate peak value within 0.5 msec even when voltage sag occurs around zero crossing. The proposed fast peak detector is compared with the conventional detector using APF, and shows faster detection time in the whole range of phase. Furthermore, the proposed fast peak detector can be effectively applied to unsymmetrical three-phase voltage sags. Simulation and experimental results verify the advantages of the proposed detector and MAPF.

[1]  Jung-Min Kwon,et al.  Photovoltaic Power Conditioning System With Line Connection , 2006, IEEE Transactions on Industrial Electronics.

[2]  Math Bollen,et al.  Experimental investigation of voltage sag mitigation by an advanced static VAr compensator , 1998 .

[3]  Byung-Moon Han,et al.  A new single-phase voltage sag/swell compensator using direct power conversion , 2009, 2009 IEEE Energy Conversion Congress and Exposition.

[4]  R. Alvarez,et al.  A Fast Detection Algorithm for Sags, Swells, and Interruptions Based on Digital RMS Calculation and Kalman Filtering , 2006, 2006 IEEE International Power Electronics Congress.

[5]  Liu Lianguang,et al.  Simulation and analysis of voltage sag mitigation using active series voltage injection , 2000, PowerCon 2000. 2000 International Conference on Power System Technology. Proceedings (Cat. No.00EX409).

[6]  J. Jeong,et al.  Novel Sag Detection Method for Line-Interactive Dynamic Voltage Restorer , 2010, IEEE Transactions on Power Delivery.

[7]  P. Pillay,et al.  A New Method of Voltage Sag and Swell Detection , 2007, IEEE Transactions on Power Delivery.

[8]  M. Barnes,et al.  Voltage sag detection technique for a dynamic voltage restorer , 2002, Conference Record of the 2002 IEEE Industry Applications Conference. 37th IAS Annual Meeting (Cat. No.02CH37344).

[9]  Hanju Cha,et al.  Mitigation of Low Frequency AC Ripple in Single-Phase Photovoltaic Power Conditioning Systems , 2010 .

[10]  N. S. Tunaboylu,et al.  Voltage disturbance evaluation using the missing voltage technique , 1998, 8th International Conference on Harmonics and Quality of Power. Proceedings (Cat. No.98EX227).

[11]  W. M. Grady,et al.  A wavelet-based procedure for automatically determining the beginning and end of transmission system voltage sags , 1999, IEEE Power Engineering Society. 1999 Winter Meeting (Cat. No.99CH36233).

[12]  Byung-Moon Han,et al.  Three-Phase Line-Interactive Dynamic Voltage Restorer with a New Sag Detection Algorithm , 2010 .

[13]  J.C. Gomez,et al.  Voltage sag mitigation by current limiting fuses , 2000, Conference Record of the 2000 IEEE Industry Applications Conference. Thirty-Fifth IAS Annual Meeting and World Conference on Industrial Applications of Electrical Energy (Cat. No.00CH37129).