Power factor correction and power quality improvement of supply grid with self-supported transformer-less DSTATCOM for different control strategies

Abstract

This paper investigates the performance of transformer-less distribution static compensator (DSTATCOM) integrated at the side of the utility distribution system for four different control strategies, viz., unit template (UT) theory, synchronous reference frame (SRF) theory, instantaneous reactive power theory (IRPT) and power balance theory (PBT). The simulation models for the three-phase three-wire power system have been designed to achieve unity power factor with different loading conditions (balanced and unbalanced linear and nonlinear loads). The DC-link is self-supported, i.e., no energy storage element is used but a DC-link capacitor is used only. DSTATCOM fulfils almost all the objectives related to the current related power quality problems created by different types of load. Here, it eliminates the harmonics, compensates reactive power which reduces the burden on the grid, makes the grid power factor unity and eliminates the load unbalances. Here, steady-state and dynamic state analysis has been discussed and comparative results have been presented.