Dynamic Voltage Restorer (DVR): Principles and Implementation in Power Systems

In this paper, we discuss the implementation of Dynamic Voltage Restorers (DVRs) for protecting power systems. The DVR represents an advanced power electronics device capable of providing instantaneous voltage compensation in electrical networks, thereby enhancing system stability and reliability. Through sophisticated control algorithms, DVR systems can detect voltage variations in real-time using fast Fourier transform (FFT) analysis or RMS calculation methods, and rapidly respond by injecting compensating currents through IGBT-based inverters to correct voltage deviations. The control logic typically involves phase-locked loop (PLL) synchronization and proportional-integral (PI) controllers to maintain precise voltage regulation. DVRs have been widely deployed across various power systems including power plants, substations, and industrial power networks. This paper provides an in-depth examination of DVR operational principles, practical applications, and advantages, along with guidance for selecting appropriate DVR configurations featuring customizable compensation ranges and response times to meet specific power system requirements.