A comparative analysis of different magnetics supported three-phase four-wire unified power quality conditioners – A simulation study

In this paper Scott-transformer supported three-phase four-wire unified power quality conditioner (3P-4W UPQC) is proposed and compared with different magnetics supported 3P-4W UPQC. Moreover, these magnetic supported 3P-4W UPQCs are also compared with the most commonly used four-leg VSI based 3P-4W UPQC in terms of % total harmonics distortions (THD) of source current and load voltage. A comparative analysis of required hardware and KAV rating of different magnetics is also given to choose the best option. A control strategy based on synchronous reference frame (SRF) with in-direct approach is used for the control of 3P-4W UPQCs. In this in-direct approach, the current/voltage control is applied over the fundamental supply currents/voltages instead of fast changing APFs currents/voltages, thereby reducing the effect of computational delay and required numbers of current sensors. The performances of the proposed topologies of UPQC are analyzed through simulations using MATLAB software with its Simulink and Power System Block set toolboxes.

► Performances of different magnetics supported 3P-4W UPQC are compared. ► Different transformers in shunt near the load compensate neutral current. ► Transformer supported 3P-4W UPQCs are realized by three-legs VSIs. ► In-direct control approach is used for the control of 3P-4W UPQCs. ► Effect of computational delay and required sensors are reduced.