Informatics Publishing Limited

S. Deepa ¹, S. Rajapandian ²

Affiliations
1 Sathyabama University, Chennai, IN
2 Panimalar Engineering College, Chennai, IN

Abstract

Dynamic Voltage Restorer (DVR) is one of the custom power devices that are used as an effective solution for the protection of sensitive loads against voltage disturbances in power distribution system. The efficiency of the DVR depends on the performance of the efficiency control technique involved in switching the inverters. Z-source inverters are recent topological options proposed for buck–boost energy conversion with a number of possible voltage- and current-type circuitries. Common feature noted is their inclusion of an LC impedance network, placed between the dc input source and inverter bridge. This impedance network allows the output end of a voltage-type Z-source inverter to be shorted for voltage boosting without causing a large current flow and the terminal current of a current-type inverter to be interrupted for current boosting without introducing over voltage oscillations to the system. Therefore, Z-source inverters are, in effect, safer and less complex and can be implemented using only passive elements with no additional active semiconductor needed. Believing in the prospects of Z-source inverters, this paper contributes by introducing a new family of embedded Z-source inverters that can produce the same gain as the Z-source inverters but with smoother and smaller current/voltage maintained across the dc input source and within the impedance network. . Simulation results are presented to illustrate and understand the performances of DVR with IEEE 30 -bus system in supporting load voltages under voltage sags conditions.

Keywords

DVR, Z-Source Inverter, Power Quality.

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S. Deepa ¹, S. Rajapandian ²

Affiliations
1 Sathyabama University, Chennai, IN
2 Panimalar Engineering College, Chennai, IN

Abstract

The dynamic voltage restorer (DVR), a custom power device, has been proposed to mitigate voltage sags, thereby protecting sensitive loads. The voltage-restoration process involves real-power injection into the distribution system. The Interline DVR (IDVR) proposed in this paper provides a way to compensate the voltage deviation caused in a feeder. The IDVR consists of several DVRs connected to different distribution feeders in the power system sharing common energy storage. Here, one DVR in the IDVR system works in voltage-sag/swell compensation mode while the other DVR in the IDVR system operate in power-flow control mode. The single phase model of the IDVR system is illustrated which is operated by Multiple Pulse Width Modulation (PWM). Close loop control for sag/swell for a simple system is modeled and simulated using MATLAB software. The simulation results are presented to demonstrate the effectiveness of the proposed IDVR system.

Keywords

Interline Power Flow Controller (IPFC), Power Flow Control Mode, Series Compensation, Total Harmonic Distortion (THD).

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