An Hybrid Multi Level Inverter Based DSTATCOM Control

This paper presents an investigation on the Hybrid Seven-Level (HSL) H-bridge inverter, which is used in a Distribution Static Compensator (DSTATCOM) in Power Systems (PS). Making use of HSLI has the benefits of low harmonics distortion, reduced number of switches required to achieve the seven- level inverter output over the conventional cascaded seven-level inverter, and also reduced switching losses. In order to compensate the reactive power and suppress the total harmonics distortion (THD) drawn from a Non-Liner Diode Rectifier Load (NLDRL) of DSTATCOM, we propose a Sub-Harmonics Pulse Width Modulation (SHPWM) technique to control the switches of HSL H - bridge inverter. The D-Q reference frame theory is used to generate the reference compensating currents for DSTATCOM and proportional and integral (PI) control is used for capacitors dc voltage regulation for DSTATCOM. An HSL H-bridge inverter is considered for the shunt compensation of a 4.5 kV distribution system. The results are validated by MatLab/Simulink simulation software.