New Active Compensator Based on IEEE Std. 1459

IEEE Standard 1459-2000 includes new definitions for the measurement of electric power quantities under sinusoidal, non-sinusoidal, balanced or unbalanced conditions. This standard is the new reference for the measurement of the power quantities related with energy flows in electric systems. These new definitions affect directly to the design of the compensating systems used to improve the electric utility quality: only positive-sequence fundamental power must be present in efficient systems and all the other power terms are non-efficient. The reference currents of active compensators had to be adapted to this new definition of the efficient power in order to eliminate the non-efficient terms. This paper proposes the design of a new set of reference currents that provides IEEE standard 1459 compliance for a four-wire three-branch active compensator. Simulation results using a three-dimensional space vector pulse width modulation (3D-3B SVPWM) are included. The loads used are three single-phase rectifiers and three unbalanced resistive loads connected to a three-phase four-wire electric system. The proposed output current control uses a current regulator and a Space Vector modulator (SVPWM). The three-phase inverter is modeled using three half-bridges and a split DC bus. The proposed three-dimensional SVPWM allow to obtain more advantage of the DC bus and allow working with a constant switching frequency.