Investigation on the performance of UPQC-Q for voltage sag mitigation and power quality improvement at a critical load point

The unified power quality conditioner (UPQC) is one of the major custom power solutions, which is capable of mitigating the effect of supply voltage sag at the load end or at the point of common coupling (PCC) in a distributed network. It also prevents the propagation of the load current harmonics to the utility and improves the input power factor of the load. The control of series compensator (SERC) of the UPQC is such that it injects voltage in quadrature advance to the supply current. Thus, the SERC consumes no active power at steady state. The other advantage of the proposed control scheme is that the SERC can share the lagging VAR demand of the load with the shunt compensator (SHUC) and can ease its loading. The UPQC employing this type of quadrature voltage injection in series is termed as UPQC-Q. The VA requirement issues of SERC and SHUCs of a UPQC-Q are discussed. A PC-based new hybrid control has been proposed and the performance of the UPQC-Q is verified in a laboratory prototype. The phasor diagram, control block diagram, simulations and experimental results are presented to confirm the validity of the theory.

[1]  Malabika Basu,et al.  Performance study of UPQC-Q for load compensation and voltage sag mitigation , 2002, IEEE 2002 28th Annual Conference of the Industrial Electronics Society. IECON 02.

[2]  B. Han,et al.  Combined operation of unified power-quality conditioner with distributed generation , 2006, IEEE Transactions on Power Delivery.

[3]  M. J. Samotyj,et al.  Voltage sags in industrial systems , 1991, Conference Record. Industrial and Commercial Power Systems Technical Conference 1991.

[4]  G. Joos,et al.  Rating issues of unified power quality conditioners for load bus voltage control in distribution systems , 2001, 2001 IEEE Power Engineering Society Winter Meeting. Conference Proceedings (Cat. No.01CH37194).

[5]  M. B. Hughes,et al.  Interpreting recent power quality surveys to define the electrical environment , 1996, IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting.

[6]  Tore Undeland,et al.  Power Electronics: Converters, Applications and Design , 1989 .

[7]  Yang Chen,et al.  One-Cycle Controlled Unified Power Quality Conditioner For Load Side Voltage Sag Compensation , 2005, 2005 IEEE 36th Power Electronics Specialists Conference.

[8]  Hirofumi Akagi,et al.  The unified power quality conditioner: the integration of series- and shunt-active filters , 1998 .

[9]  M. Linan,et al.  Power quality in high-tech plants: a case study , 2005, IEEE Compatibility in Power Electronics, 2005..

[10]  S. S. Choi,et al.  Modelling, analysis and control of unified power quality conditioner , 1998, 8th International Conference on Harmonics and Quality of Power. Proceedings (Cat. No.98EX227).

[11]  E. Coyle,et al.  Optimal control strategy of UPQC for minimum operational losses , 2004, 39th International Universities Power Engineering Conference, 2004. UPEC 2004..

[12]  M. Parniani,et al.  Mitigation of electric arc furnace disturbances using the unified power quality conditioner , 2004, 30th Annual Conference of IEEE Industrial Electronics Society, 2004. IECON 2004.

[13]  M. Aredes,et al.  A control strategy for unified power quality conditioner , 2003, 2003 IEEE International Symposium on Industrial Electronics ( Cat. No.03TH8692).

[14]  A. Ghosh,et al.  A unified power quality conditioner for voltage regulation of critical load bus , 2004, IEEE Power Engineering Society General Meeting, 2004..

[15]  Dong-Seok Hyun,et al.  A new control scheme of unified power quality compensator-Q with minimum power injection , 2004, 30th Annual Conference of IEEE Industrial Electronics Society, 2004. IECON 2004.

[16]  Malabika Basu,et al.  Comparative evaluation of two models of UPQC for suitable interface to enhance power quality , 2007 .

[17]  Mauricio Aredes,et al.  An universal active power line conditioner , 1998 .

[18]  E. Tironi,et al.  A survey on power quality cost in industrial customers , 2001, 2001 IEEE Power Engineering Society Winter Meeting. Conference Proceedings (Cat. No.01CH37194).

[19]  Shyama P. Das,et al.  An Optimum UPQC with Minimum VA Requirement and Mitigation of Unbalanced Voltage Sag , 2005 .