Advanced power quality control of ultracapacitor connected solar energy system instead of DC link in distribution level [articol]

Abstract

This research paper presents a new approach for achieving maximum utilities from the grid-interfacing inverters using the modified PI controller viz., AWPI and SMC controller. When installed 3-phase 4-wire distribution systems to achieve the voltage profile of system. Usually, the photovoltaic energy sources generate power at variable low dc voltage, Thus, the power generated from these renewable sources are interconnect using various converters before connecting on dc-link. In this proposed work, a maximum power point tracking (MPPT) scheme has been used to obtain maximum power from the renewable energy system and DC/DC converter is implemented to maintain a constant DC voltage. The universal inverter is controlled to perform as a multi-function device by incorporating active power filter functionality. System transients are suppressed and normal conditions are quickly restored with shunt APF and Ultracapacitor instead of DC link capacitor. So, it can be concluded that Ultracapacitor based energy storage technology can be used to enhance the operating capability of APF to maintain high quality grid voltage. Ultracapacitor is very fast in charging and discharging compared to traditional DC link capacitors which is needed to restore the system. Finally, the performance of the system can be analyzed and implemented by incorporating Sliding Mode Controller (SMC) and Anti-windup PI (AWPI) controller with modified ultra-capacitor filter circuit in the PI Controller. This new control concept is demonstrated with extensive MATLAB / Simulink.