Load Compensation by DSTATCOM with LCL-Filter by Comparing Different Resonance Damping Methods

This paper presents the design of a Distribution Static Compensator (DSTATCOM), interfacing the grid with an inductor-capacitor-inductor (LCL) filter, controlled by using dq0 current controller and sinusoidal pulse-width modulation (SPWM). A four-wire two-level voltage source converter (VSC) to operate as the DSTATCOM was connected at the point of common coupling (PCC) via the LCL-filter for neutral current compensation/load balancing, reactive power compensation, and harmonics elimination. The design of the LCL-filter for high switching ripple attenuation was introduced by incorporating two resonance damping techniques, namely, active damping (AD) and passive damping (PD). Besides, the design of the dq0 current controller was presented in detail. Load balancing, harmonic elimination, and reactive power compensation were performed using a simulation model of the DSTATCOM system. The dq0 current controller was implemented in the synchronous reference frame (SRF) rotating at the fundamental frequency and was composed of harmonic compensation (HC) regulators—realized by the sum of sinusoidal signal integrators (SSI)—connected in parallel to the proportional-integral (PI) regulators. Neutral current compensation was also carried out to address unbalanced loads using a 0-axis controller. Lastly, the effects of the AD and PD methods on the efficiency and dynamic performance of the system were provided.