3P4SW and 3P9SW Based UPQC Topologies to Improve the Power Quality in Medium Voltage Distribution System

Background: The undesirable effect of power quality issues on distribution system due to power electronics based controllers; it is highly desired to design a novel power quality conditioner with a minimum number of switches. The proposed configuration reduces the switching loss and also effectively alleviates the power quality issues. This paper introduces the configuration of 3P4SW (Three Phase Four Switch) UPQC (Unified Power Quality Conditioner) for both shunt and series APF (Active Power Filter) as well as 3P9SW (Three Phase Nine Switch) UPQC topologies, which can be implemented in medium voltage power grid. The major challenge of phase balance with only four switches in UPQC is accomplished by adaptive Self-tuning PID using neuro-fuzzy logic control and adaptive reference current generation scheme. This controller improves sag and swells compensation with better angle control via shunt and series converter performance and passive components design. The efficacy of proposed topology is tested on MATLAB/Simulink software and results are compared with the existing three phase six switch configuration (3P6SW). Methods: The main objective of this work is to identify the most suitable configuration of UPQC to mitigate the power quality issues in power distribution system. to achieve this goal a Synchronous reference frame theory is used to generate the pulses in the back to back connected VSI in UPQC. Results: The suggested topologies should not compromise with the nominal functions of the controller; hence from the simulation analysis it clear that the 3P4SW UPQC, as well as 3P9SW UPQC topologies, will fulfill the given constraints and also it maintains the magnitude of the load voltage as per the standard values. Also, the THD percentage is maintained well within the IEEE standard. Conclusion: The proposed topologies can be implemented for medium voltage distributed system with improved power quality.