DSTATCOM with LCL filter using synchronous reference frame current controller

This paper presents a inductor-capacitor-inductor (LCL) filter with sine pulse width modulation (SPWM) based switching control strategy for two-level neutral-point-clamped (NPC) voltage source inverter (VSI) in Distribution Static Compensator (DSATCOM). Interface LCL filter between VSI and point of common coupling (PCC) is used to minimize the switching harmonic ripple in compensated PCC voltage and source currents. Modeling, design details of LCL filter are presented and synchronous reference theory is used for reference filter current generation. Synchronous reference frame (dqo) current controller with proportional integral (PI) and sinusoidal signal integral (SSI) regulators, along with active damping feature for LCL filter (using filter capacitor current feed back) is used for proper control and operation of DSTATCOM. Detailed simulation study to compensate unbalanced nonlinear load with interface LCL filter and L filter DSTATCOM is carried out in PSCAD 4.2.1 simulator, and the corresponding results are presented.