D-STATCOM: A study on the NPC multilevel inverter and control strategies

This paper confers the relativistic study and analysis on the characteristic of neutral point clamped multilevel inverter (NPCMLI) (three to eleven level) with fixed DC link voltage and with distinct pulse width modulation (PWM) competence, as a Distribution Static Compensator (D-STATCOM) which counterbalances the current harmonics, unbalanced load and reactive power in a typical three-phase three wire medium voltage distribution power system. The agility of the D-STATCOM depends upon the control strategy. The conventional control strategies like synchronous detection method (SDM), synchronous reference frame theory (SRFT) and instantaneous pq theory (IPQT) were availed to gauge the compensating currents for imparting optimum results in repressing harmonics originated from non-linear loads. The MATLAB simulation results were leveraged for comparative analysis and performance evaluation of NPCMLI at different levels with various control strategies.