PERFORMANCE EVALUATION OF ADVANCED DC-DC CONVERTERS FOR BLDC MOTOR DRIVEN STANDALONE SOLAR WATER PUMPING SYSTEM

Abstract

The increment in advanced technology for pumping applications has been possible due to very swift development in power semiconductor devices. At the same time the reliable and stable operation of whole system is affected due to presence of harmonic distortions being produced by power converters which then results in additional losses. The DC-DC converters are known for converting DC voltage level of output with respect to input via control of duty cycle of principal switches present in the circuits. The necessity of these converters is subject to supplying a constant output voltage, without being affected by input voltage disturbances. The two parts of designing Standalone Solar Water Pumping System (SSWPS) comprises of the passive components selection and the optimized composition of control system. This project presents the complete comparative analysis by considering the overall procedure for implementation of optimum design and control of SSWPS, which primarily comprises of a Permanent Magnet Brush-Less DC (PMBLDC) motor coupled to pump, a configuration of Voltage Source Inverter (VSI), a high gain Advanced DC-DC Converter (ADDC) and a Solar Photo-Voltaic (SPV) array. The idea of designing passive components is such that the operation of inductor of ADDC, even at lower sun radiation, should remain in Continuous Conduction Mode (CCM). Whereas, in designing of control system the optimization of system parameters is done so that cognitive control of ADDC’s switching via Incremental Conductance-Maximum Power Point Tracking (INC-MPPT) algorithm for drawing the paramount obtainable power from SPV array can be made possible. Also, this algorithm offers a reduced current starting (i.e., soft starting) to the PMBLDC motor, deployed for driving a centrifugal water pump coupled to its shaft, which restrain motor from the damaging consequence of high starting current. In order to avoid the VSI switching losses due to high frequency switching a proper electronic commutation circuitry for PMBLDC motor is employed. In order to achieve the desired performance of BLDC motor, there is an immense requirement of proper speed controller and an input supply having low ripple value. Thus, by integrating PI controller with an ADDC, an attempt has been made to implement a better speed control system for the BLDC motor drive. The specifications of the controller have been fine-tuned to optimize motor performance. Also, the relative performance evaluation of three different ADDCs such as Luo converter, Single-Ended Primary-Inductance Converter (SEPIC) and ZETA converter have been calculated and analysed by using the respective converter mathematical analysis and summarized in tabulation form. Considering PMBLDC motor drive as load, the transient and steady state analysis of all the designed ADDCs has been carried out in terms of voltage, current and power. In addition, the performance parameters values such as ripple voltage, switching losses and efficiency of the proposed three different converters were compared with each other in open as well as closed loop control system environment. The suitability of the intended system under dynamic conditions is demonstrated by the simulation results using MATLAB/Simulink software.