Laboratory test of a dynamic voltage restorer model using estimation of the filter capacitor current

Dynamic voltage restorer (DVR) is a power electronic device used to compensate supply voltage disturbances e.g. voltage dips. The paper describes laboratory model of 3-ph dynamic voltage restorer with a multiloop controller which uses a gradient estimator of the capacitor current. The estimator allows for dynamical properties improvement without measuring actual signals. The DVR utilizes progressive phase advance stragy to minimize active power injection and conserves the stored energy. Results of experimental tests are presented in the paper.