A Control Strategy for High Quality of Hybrid DC Power Supply with Auto-correcting Ultracapacitor Voltage

In this paper, a new control strategy is designed and evaluated for a Hybrid DC power supply that provides regulated DC bus voltage, and the fast transient response against load variation and source variations. The proposed DC bus is powered by a Solar photovoltaic source and supported with a battery and ultracapacitor storage. The averaged model is developed for the system under study and established its control strategy. The same model is used to determine compensator parameters used in various loops of the control strategy. After serving each transient, the perturb value of ultracapacitor voltage is brought back to nominal value using the proposed control strategy to prepare it for the future transient. Bi-directional converter associated with ultracapacitor is regulating DC bus voltage against load and source variations. The battery is providing a prolonged backup for the entire system. Analytically derived compensators for feedback and feedforward loops are verified by simulation results

Efficiency Assessment of BLDC type Solar Water Pumping System fed by Photovoltaic and Grid

This paper optimizes the operation of Brushless DC motor (BLDC) operated solar water pumping system. The proposed system is assisted with single phase supply to ensure the system operation in the high efficiency zone which is governed by the pump. In conventional systems consisting of either AC supply or PV leads to low reliable and inconsistent operation of the motor for water pumping applications. The proposed system consists of Power Factor Correction (PFC) converter for grid input, DC-DC converter as MPPT channel for PV, and three phase inverter to control BLDC type motor-pump set. The entire system is equipped with the control strategy which has multiple modes of operation based on availability of sources. The modelling of all the power converters and their compensator design are provided in this paper. Performance of the system is investigated using developed test-bed with water-pump, tank, power conditioning unit, solar PV simulator, and grid supply. The control strategy and overall system efficiency is verified by simulation and experimental results. © 2021 IEEE

Performance comparison of controllers for solar PV water pumping applications

This paper presents a detailed comparison of two different electronic controllers used for driving Solar Photovoltaic water pumping systems in India. A recently developed Sine-wave Pump Controller with MPPT (SPCM) having two stage converter topology offered better performance throughout the operational range, over the most popular controllers using the Variable Frequency Drives (VFD). This paper presents an exhaustive study of SPCM and VFD based controllers in terms of their operational performance at 10 m, 18 m and 20 m head, in terms of quality of output power and quantity of the total water delivered when connected to the same motor-pump set under similar conditions. SPCM with best MPPT efficiency of 99.4%, lowest THD of less than 3% and pumped 30% to 70% more water for same heads. The overall system efficiency of SPCM based pump is 18% higher than VFD based pumping system for the head corresponding to duty point. The output power quality of SPCM is considerably high, with superior sine-wave (crest-factor 1.42 and 1.56 for voltage & current), ensures no voltage spikes even at 60 m of cable length. Thus, the paper establishes performance dominance of SPCM over the VFD based controller through the measurement on actual sample. (C) 2015 Elsevier Ltd. All rights reserved