Two low-voltage converters are connected in such a way that one converter is connected back to the other converter back side with DC capacitor. Such an arrangement of low-voltage converters is called unified power quality conditioner (UPQC). The UPQC is categorized on the basis of sharing of active and reactive power through series converter to inject voltage. When series converter of the UPQC uses active power to enhance voltage quality, the UPQC is called as UPQC-P; when series converters of the UPQC use reactive power to enhance the voltage quality, the UPQC is called as UPQC-Q. And when series converter of the UPQC uses complex power to enhance voltage quality, it is called as UPQC-S. These kinds of UPQC depend on controller of gate firing of the UPQC. These control approaches have been verified on MATLAB platform.