A Novel Modified P-Q Theory to Control PV-UPQC under Power Quality Issues in Distribution System

  • J. Sandhya Rani
  • Dr. Rashmi Kapoor


This paper deals with the design and performance analysis of a three-phase single stage solar photovoltaic integrated unified power quality conditioner (PV-UPQC). The PV-UPQC consists of a shunt and series connected voltage compensators connected back to back with common DC-link. The shunt compensator performs the dual function of extracting power from PV array apart from compensating for load current harmonics. The system incorporates clean energy generation along with power quality improvement thus increasing functionality of the system. The fundamental frequency positive sequence (FFPS) components of voltages at the point of common coupling (PCC) are extracted using generalized cascaded delay signal cancellation (GCDSC) technique which are then used in p-q theory based control to estimate reference signals for the PV-UPQC. The series compensator compensates for the grid side power quality problems such as grid voltage sags/swells. The compensator injects voltage in-phase/out of phase with point of common coupling (PCC) voltage during sag and swell conditions respectively. The proposed system combines both the benefits of clean energy generation along with improving power quality. The steady state and dynamic performance of the system are evaluated by simulating in Matlab/Simulink under various loading conditions like nonlinear load, Induction motor, sudden changes in loads connected and faults.

Keywords: Distribution system, Power Quality, Sag/Swell, Non-Linear load, PV-UPQC, PCC


Download data is not yet available.


[1] S.Devassy and B. Singh, “Modified p-q theory based control of solar PV integrated UPQC-S,” in IEEE Industry Applications Society Annual Meeting, Oct 2016.
[2] Y. Yang, P. Enjeti, F. Blaabjerg, and H. Wang, “Wide-scale adoption of photovoltaic energy: Grid code modifications are explored in the distribution grid,” IEEE Ind. Appl. Mag., vol. 21, no. 5, pp. 21–31, Sept 2015.
[3] B. Singh, A. Chandra and K. A. Haddad, Power Quality: Problems and Mitigation Techniques. London: Wiley, 2015.
[4] M. Bollen and I. Guo, Signal Processing of Power Quality Disturbances. Hoboken: Johm Wiley, 2006.
[5] P. Jayaprakash, B. Singh, D. Kothari, A. Chandra, and K. Al-Haddad, “Control of reduced-rating dynamic voltage restorer with a battery energy storage system,” IEEE Trans. Ind. Appl., vol. 50, no. 2, pp. 1295–1303, March 2014.
[6] M. Badoni, A. Singh, and B. Singh, “Variable forgetting factor recursive least square control algorithm for DSTATCOM,” IEEE Trans. Power Del., vol. 30, no. 5, pp. 2353–2361, Oct 2015.
[7] A. Rauf and V. Khadkikar, “An enhanced voltage sag compensation scheme for dynamic voltage restorer,” IEEE Trans. Ind. Electron., vol. 62, no. 5, pp. 2683–2692, May 2015.
[8] V. Khadkikar, “Enhancing electric power quality using PV-UPQC: A comprehensive overview,” IEEE Trans. Power Electron., vol. 27, no. 5, pp. 2284–2297, May 2012.
[9] B. Han, B. Bae, H. Kim, and S. Baek, “Combined operation of unified power-quality conditioner with distributed generation,” IEEE Trans. Power Del., vol. 21, no. 1, pp. 330–338, Jan 2006.
[10] B. Singh, C. Jain, and S. Goel, “ILST control algorithm of single stage dual purpose grid connected solar pv system,” IEEE Trans. Power Electron., vol. 29, no. 10, pp. 5347–5357, Oct 2014.
[11] N. D. Tuyen and G. Fujita, “PV-active power filter combination supplies power to nonlinear load and compensates utility current,” IEEE Power and Energy Technology Systems Journal, vol. 2, no. 1, pp. 32–42, March 2015.
[12] M. Davari, S. Ale-Emran, H. Yazdanpanahi, and G. Gharehpetian, “Modeling the combination of PV-UPQC and photovoltaic arrays with multi-input single-output dc-dc converter,” in IEEE/PES Power Systems Conference and Exposition, 2009. PSCE ’09., March 2009, pp. 1–7.
[13] B. Subudhi and R. Pradhan, “A comparative study on maximum power point tracking techniques for photovoltaic power systems,” IEEE Transactions on Sustainable Energy, vol. 4, no. 1, pp. 89–98, Jan 2013.
[14] L. Czarnecki, “Constraints of instantaneous reactive power p-q theory,” IET Power Electronics, vol. 7, no. 9, pp. 2201–2208, September 2014.
[15] M. Kesler and E. Ozdemir, “Synchronous-reference-frame-based control method for PV-UPQC under unbalanced and distorted load conditions,” IEEE Trans. Ind. Electron., vol. 58, no. 9, pp. 3967–3975, Sept 2011.
[16] N. Tummuru, M. Mishra, and S. Srinivas, “Multifunctional VSC controlled microgrid using instantaneous symmetrical components theory,” IEEE Transactions on Sustainable Energy, vol. 5, no. 1, pp. 313–322, Jan 2014.
25 Views | 16 Downloads
How to Cite
Rani, J. S., & Kapoor, D. R. (2018). A Novel Modified P-Q Theory to Control PV-UPQC under Power Quality Issues in Distribution System. Asian Journal For Convergence In Technology (AJCT) ISSN -2350-1146, 4(II). Retrieved from https://asianssr.org/index.php/ajct/article/view/613