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.