Design and implementation of a low cost, low loss energy quality regulator for energy distribution systems

The Energy Quality Regulator (EQR) is the solution for reactive power compensation, neutral current compensation, load balancing and harmonic current mitigation. In this thesis, design and simulation of a distribution type, voltage source inverter (VSI) based having two level inverter topologies have been carried out. The thesis is dedicated to detailed analysis, design, control, simulation and implementation of EQR for a three-phase four-wire nonlinear, unbalanced, and non-resistive loads. The power stage of VSI based EQR is composed of naturel air forced discrete IGBT modules switch at 5 kHz to reduce switching losses. The three-leg four-wire VSI topology utilizes a standard three phase PWM inverter bridge and the neutral wire is connected to the midpoint of the dc-link. Properly designed, the LCL supply filter is used instead of L type filter in this work since it provides a much better suppression at the modulation frequency. Whole compensation reference currents are extracted in the synchronous reference frame. Control has been carried out in selective manners. The proposed VSI based EQR has been implemented after the PQ measurement for the reactive power compensation, neutral current compensation, load balancing and 3., 5., 7., harmonics current elimination of the distribution type transformer station which is 400kVA, %4 uk belongs to the Mediterranean Electricity Distribution Company. Keywords: Flexible AC Transmission Systems (FACTS), Power Quality (PQ), Reactive Power Compensation, Neutral Current Compensation, Load Balancing, Zero and Negative Sequence Compensation, Harmonic Current Mitigation, Synchronous Reference Frame, Proportional-Resonant Controller (PR)