Dynamic Voltage Restorer (DVR): A Comprehensive Review of Topologies, Power Converters, Control Methods, and Modified Configurations

Abstract

Power quality is a pressing concern and of the utmost importance for advanced and high-tech equipment in particular, whose performance relies heavily on the supply’s quality. Power quality issues like voltage sags/swells, harmonics, interruptions, etc. are defined as any deviations in current, voltage, or frequency that result in end-use equipment damage or failure. Sensitive loads like medical equipment in hospitals and health clinics, schools, prisons, etc. malfunction for the outages and interruptions, thereby causing substantial economic losses. For enhancing power quality, custom power devices (CPDs) are recommended, among which the Dynamic Voltage Restorer (DVR) is considered as the best and cost-effective solution. DVR is a power electronic-based solution to mitigate and compensate voltage sags. This paper provides a thorough discussion and comprehensive review of DVR topologies based on operations, power converters, control methods, and applications. The review compares the state-of-the-art in works of literature, and comparative study on power quality issues, the DVR principle along with its operation modes, the DVR components, the DVR topologies based on energy storage, the DVR topologies based on single-/three-phase power converters, and the DVR topologies based on control units that have different control processing stages. Furthermore, modified and improved configurations of the DVR, as well as its integration with distributed generations, are described. This work serves as a comprehensive and useful reference for those who have an interest in researching DVRs.

Attenuation of Zero Sequence Voltage Using a Conventional Three-Wire Dynamic Voltage Restorer

“…The emergent use of such devices motivated discussions about power quality issues, which resulted in researches on solutions that could mitigate them. In this scenario, the dynamic voltage restorer (DVR) was proposed to compensate for momentary voltage disturbances and has been intensively studied in recent decades [1][2][3][4][5][6].…”

“…Regarding the state of the art, the power converter topologies that are mostly used in three-phase DVRs are [6]: two-level (three-wire) inverters; two-level (four-wire) inverters with split-capacitor; four-leg (four-wire) inverters; and three single-phase H-bridge inverters [8][9][10][11]. These DVR topologies are typically used in low-voltage grid applications due to the simplicity of their modulation methods and due to their lower costs when compared to multilevel solutions.…”

“…As the grid voltages are raised to medium-voltage level, the two-level topologies mentioned above become disadvantageous due to the voltage and currrent limitations of their semiconductor switches. Alternative options for medium-voltage grid application are [6]: using series-parallel associations of semiconductor switches to increase their maximum blocking voltages and operating currents; or using multilevel inverters [12][13][14]. However, regardless of the DVR topology used, the solutions for medium-voltage can still be classified into three-wire or four-wire.…”

“…When focusing on voltage sags/swells that contain zero sequence components, e.g., a single-phase sag [15,16], it is established in the literature that a three-phase three-wire DVR (Figure 1), such as the scheme based in a two-level inverter, which is referred as conventional DVR in this paper, cannot compensate for these disturbances. As consequence, several authors have proposed new DVR topologies to solve this problem, such as the threephase four-wire DVR with split capacitors and the four-leg DVR [6,16], both mentioned in the previous paragraph.…”

Hybrid self‐learning controller for restoration of voltage power quality using optimized multilayer neural network

“…This is achieved by injecting the amount of voltage required for the smooth voltage regulation. 5,6 The problem is with the high amplitude of voltage disturbances it needs to be scaled within the appropriate range by effective tuning of the controller parameters. The demerit of the classical tuning techniques such as PI, Ziegler-Nichols (Z-N), and Cohen-Coon is they consume more time for tuning under the parametric variations.…”