What question did this study set out to answer?

The aim is to evaluate and compare the performance of DPFC and UPFC in power flow management.

April 12, 2026Open Access

A comparative simulation analysis of distributed power flow controller performance on transmission system enhancement

Key Points

The aim is to evaluate and compare the performance of DPFC and UPFC in power flow management.
Simulation of DPFC and UPFC using MATLAB/Simulink
Assessment of active power exchange characteristics
Evaluation of total harmonic distortion and voltage stability under normal and fault conditions
DPFC transfers 0.301 MW of active power vs. 0.290 MW from UPFC under normal conditions
DPFC shows lower voltage THD of 9.04% compared to 15.26% for UPFC
Under fault conditions, DPFC delivers 0.280 MW active power vs. 0.250 MW from UPFC
DPFC provides increased reactive power output of 0.072 MVAR compared to UPFC's 0.058 MVAR

Abstract

Abstract Globally all power utilities are striving to cater to the ever-increasing demand for electrical energy by either adding new transmission lines or by optimizing the already existing ones with an objective of transmitting higher degrees of power. The construction of new transmission infrastructure, however, is limited by higher costs and regulatory hurdles. Also, the flow of power in transmission networks oftentimes follows very undesirable pathways and system stability is heavily dependent on voltage changes between lines. A successful answer to these problems is the intelligent regulation of power flow in transmission network. This study provides high-level operational evaluation of Flexible Alternating Current Transmission System (FACTS) strategies, namely Unified Power Flow Controller (UPFC) and Distributed Power Flow Controller (DPFC), which are analysed through their active power exchange characteristics. The UPFC has a common DC link among its shunt-series converters. On the other hand, DPFC does not require a common DC-link and instead replaces each of three‑phase series converters with multiple single‑phase distributed converters which are placed along the transmission line. MATLAB/Simulink is used for modelling and simulation of UPFC and DPFC operating behaviours to observe their performance in controlling power flow with respect to Total Harmonic Distortion (THD). It can be seen from the load flow simulation results, under normal operation condition DPFC transfer larger amount of the active power (i.e., 0.301 MW vs. 0.290 MW) with lower voltage THD (i.e., 9.04% vs. 15.26%) than UPFC. In a three-phase faults scenario, the DPFC continues to carry out better performance with 0.280 MW active power (i.e., UPFC: 0.250 MW), 0.072 MVAR reactive power (i.e., UPFC: 0.058 MVAR) and minimized voltage THD. These findings show that the DPFC outperforms all other FACTS devices in terms of voltage stability and power transfer capacity, confirming its increased reliability for applications involving transmission systems.

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