A multilevel converter with reduced number of switches in STATCOM for load balancing

• We designed a noval AC to DC converter for STATCOM application, it can be operated single or three-phase.
• New converter has less number of switches used than H-bridge structure has.
• PWM technique can be used on converter like conventional H-bridge structure.

In this paper, a 3-phase, delta-connected, 5-level Static Synchronous Compensator with a novel AC to DC converter is analyzed and implemented for load balancing in three-phase systems. The level shifted carrier based sinusoidal pulse width modulation (SPWM) method is used as the switching technique. This converter has less number of power switches than conventional H-bridge structure and it can be controlled from the standard PWM ports of microcontrollers. The control algorithm depends on sequence decomposition of load current and compensation of its negative sequence component in addition compensation of imaginary component of positive sequence. The simulation results obtained from Matlab are compared with the experimental results. The system is implemented in the laboratory by using DSP TMS320F28335.