Design of a SRF Based MC UPQC Used for Load Voltage Control in Parallel Distribution Systems


This paper deals with a new design dynamic model of synchronous-reference- frame (SRF)-based control in three phase system under different load considerations to improve power quality by using power conditioner with multi converters. The proposed MCUPQC system can regulate the load voltages/bus voltages on Parallel power distribution systems under balanced and distorted load conditions and obtain the state space model for MC-UPQC. The simulation results to support the SRF-based control method presented in this paper is done using Matlab/Simulink.



  1. Power quality (PQ)
  2. Active power filter (APF)
  3. Synchronous reference frame (SRF) and multi converter
  4. Unified power-quality conditioner (MC-UPQC)





Fig.1.The single line diagram of conventional MC-UPQC



Fig. 2.a and b. the phase bus voltage, VS1 and load voltage VL1

Fig. 3.c and d. the phase bus voltage, VS2 and load voltage VL2

Fig.4.a & b. the phase Source Current, IS1 and Load CurrentIL1

Fig. 5 and 6 .a, b and c. The phase bus voltage, injected voltage and load Voltages

Fig. 7.a, b and c. The phase Source Currents (IS1), load Currents (IL1) and DC Capacitor Voltage(VDC).

Fig. 8.a, b, c, d, e and f. the phase bus voltage (VS1), load Voltages (VL1), load Voltages (VL2), the phase source currents (IS1), load Currents (IL1) and DC Capacitor Voltage (VDC).



In this paper the SRF Based control MC-UPQC for regulates of load voltage and load current in adjacent parallel feeder has been proposed and compared to a conventional MC-UPQC, the proposed control topology is capable of fully protecting critical and sensitive loads against sudden changing loads, voltage sag/ swells, and fault interruption in two-feeder distribution systems. The performance of the SRF based MC-UPQC is tested under various disturbance conditions.



  • G. Hingorani “Introducing custom power,” IEEE spectrum, vol.32, June 1995, pp. 41-48.
  • Ray Arnold “Solutions to Power Quality Problems” power engineering Journal, Volume 15; Issue: 2 April 2001, pp: 65-73.
  • John Stones and Alan Collision “Introduction to Power Quality” power engineering journal, Volume 15; Issue 2, April 2001, pp: 58- 64.
  • Fujita and H. Akagi, “The unified power quality conditioner: The integration of series and shunt active filter,” IEEE Trans. Power Electron. , vol. 13, no. 2, pp. 315–322, Mar. 1998..
  • Gyugyi, C. D. Schauder, S. L. Williams, T. R. Rietman, D. R. To rjerson, and A. Edris, “The unified power flow controller: A new approach to power transmission control,” IEEE Trans. Power Del. , vol. 10, no. 2, pp. 1085–1097, Apr. 1995.

Leave a Reply

Your email address will not be published. Required fields are marked *