An Investigation of Solar Photovoltaic Power Fed Induction Motor Drive

Abstract

In general, the growth of a county is measured in terms of one of the parameters, electrical power consumption. So, in the progressive world, the amount of electrical energy consumption is increasing exponentially. However, traditional power generation mainly depends on fossil fuels. The major concerns associated with fossil fuels are limited in nature, low efficiency, and high cost. In addition, power generation using fossil fuels not only causes a greater part of the pollution but also unbalances the ecosystem. Hence, the world requires clean energy sources for sustainable growth. Renewable energy sources such as solar, wind, tidal, etc. are available for clean power generation. Among the available renewable energy sources (RESs), wind and solar electrical power generation are dominating the current electrical market. Wind turbines have high energy conversion efficiency as compared to solar. But, due to easy installation, less maintenance, and noise solar energy is highly preferred than other RESs. Solar photovoltaic (SPV) panels convert solar energy into direct electric current. Hence, SPV power is used for domestic, agricultural, and industrial appliances as solar energy is freely available and the cost of SPV panels is less. The utilization of SPV-fed motor drives is increasing day by day. Especially, for solar water pumping applications induction motor (IM) drives are used due to their rugged and reliable operation as compared to other commercial electrical drives. Therefore, a part of research is focused on SPV-fed AC drives especially IM appliances, and the evolution of various configurations of SPV-fed IM drives and control so that they can be effectively employed in required applications. Moreover, the concern associated with the SPV system is the variable output power. Hence, overcoming this problem without any storage system can be achieved using a variable-speed IM drive operation. The control of the IM drive had been carried out using inverter pulse width modulation (PWM) control. These PWM methods are likely sinusoidal PWM (SPWM), third harmonic injection method (THIPWM), etc. In the THIPWM method, enhancement of the DC bus utilization by 15.5 % more than SPWM with increased linear modulation index range by 0.907. For implementing both the attributes of THIPWM at a time, the conventional space vector duty ratio control (CSVDRC) is used to further improve the switching losses than the SPWM and THIPWM. Moreover, the CSVDRC improves the current ripple slightly with a significant increase in computation. Another method of PWM also known as hybrid duty ratio control gives reduced current THD for modulation index (MI) in between the range of 0.5 to 0.907 as compared to CSVDRC at a given average switching frequency. So, in this thesis, the hybrid duty ratio control is used to further improve the overall ripple performance of the SPV-fed IM drive. Moreover, to further reduce the overall cost of SPV-fed IM drives, reduced switch count-based inverter topology is also implemented for both two-stage and single-stage operations. With the help of solar simulator and DSPACE-DS 1104, the proposed concepts are implemented experimentally and compared the results with conventional control techniques. However, the real-time controlled pulses for the converter circuits are generated using DSPACE DS-1104.