Power Control With Z-Source Converter Based Unified Power Flow Controller

• Published in: IEEE transactions on power electronics Vol. 32; no. 12; pp. 9413 - 9423
• Main Authors: Thirumalaivasan, R., Xu, Yunjian, Janaki, M.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.12.2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Active control; Analytical models; Capacitors; Compensation; Computer simulation; Data buses; Electric converters; Electric potential; Electric utilities; Linear analysis; Power control; Power conversion; Power flow; Power transmission lines; Pulse duration modulation; Reactive power; Space vector pulse width modulation; space vector pulse width modulation (SVPWM); Switching; transient simulation; Transmission lines; unified power flow converter (UPFC); Voltage control; Z-source converter (ZSC)
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2017.2657798

In this paper, we propose a Z-source converter (ZSC)-based unified power flow controller (ZSC-UPFC) to enhance power control for long transmission lines. As a multifunctional controller, the UPFC has been adopted to regulate both the active and reactive power flows in transmission lines and to control the AC bus voltage. A recently proposed converter topology, ZSC, uses a Z-network on its DC side to support the desired AC output voltage. The proposed ZSC-UPFC configuration places a Z-network between the dc-link capacitor and the series converter to boost the series converter DC voltage. The integration of Z-network provides the desired converter voltage even with reduced dc-link capacitor voltage setting. We develop a detailed three-phase model for the proposed ZSC-UPFC by modeling the converter operation with switching functions, which are generated by the space vector pulse width modulation (SVPWM) technique. We conduct linear analysis on the D-Q model as well as extensive transient simulation (based on a detailed nonlinear three-phase model) to evaluate the performance of the overall system with the proposed ZSC-UPFC configuration. Our simulation results demonstrate the effectiveness of ZSC-UPFC: 1) The series converter provides the series compensation in a long transmission line with Z-network, and 2) the shunt converter maintains a constant dc-link capacitor voltage and provides reactive power support for the AC bus.