Current Balancing in Electric Power Networks Using an Electronic Inactive-Power Regulator

Abstract

A device for balancing currents in three-phase power supply networks has been examined that contains a three-phase semiconductor converter, output matching chokes, and capacitor batteries on the side of the dc converter. The feedback of the controller system is organized by the magnitude of choke current. The algorithm for determining reference signals is implemented by means of separate calculation of currents of the direct, reverse, and zero sequences using the Park–Gorev transformation equations. Pulse-width modulation of the converter voltage is used to modulate the calculated signals. To study the operation of a power compensator, unbalance and control algorithms, a computer model has been developed in the MATLAB/Simulink program using the SimPowerSystems library. The results of experiments with a physical prototype of a regulator with a power of 3 kVA performing compensation of unbalanced currents are presented. Diagrams are given in the case of current balancing in a three-phase network with and without a neutral wire when one phase is broken. Diagrams are also presented in the case of combining the functions of reactive power balancing and compensation.