• Energy Research

This research work presents a modified sine-cosine optimized maximum power point tracking (MPPT) algorithm for grid integration. The developed algorithm provides the maximum power extraction from a photovoltaic (PV) panel and simplified implementation with a benefit of high convergence velocity. Moreover, the performance and ability of the modified sine-cosine optimized (MSCO) algorithm is equated with recent particle swarm optimization and artificial bee colony algorithms for comparative observation. Practical responses is analyzed under steady state, dynamic, and partial shading conditions by using dSPACE real controlling board laboratory scale hardware implementation. The MSCO-based MPPT algorithm always shows fast convergence rate, easy implementation, less computational burden and the accuracy to track the optimal PV power under varying weather conditions. The experimental results provided in this paper clearly show the validation of the proposed algorithm.

A unique nonisolated converter using solar source as input is depicted in this paper. The presented design is an amalgamation of SEPIC converter and voltage tripler structure to attain high static gain voltage. The converter operates by solitary switch, and the voltage strain is less. The input current is continuous, and hence, huge filters are not utilized. Henceforth, the proposed converter is suitable for renewable application. The presented converter is associated to the PV source input and DC load source. The hardware sample of the presented converter along with the PV simulator is tested under laboratory. The prototype of a 30-V input source to 400-V source output developed 400 W, and the performance of the designed topology is evaluated. The theoretical and hardware results accomplish that this converter is apt for high-voltage solicitations.

The pulse width modulation (PWM) is an important segment in power electronic inverters and multilevel inverters (MLIs) design. The space vector modulation (SVM) methods own distinct advantages over other PWM methods. However, MLI SVM has involved more mathematics in their executions. Hence, the digital signal processors (DSPs) or field programmable gate arrays (FPGAs) based digital implementations are highly preferred for MLI SVM realizations, which require exceptional properties. The conventional MLI SVMs use complex mathematical functions to solve their internal functions to identify the space vector diagram (SVD) sub-triangle and over modulation boundary switching on-times. Particularly these are the changes in the position of reference vector with respect to their sub-triangle positions involving higher mathematical functions. This paper proposes a simplified three-level MLI SVM that reduces the sub-triangle and over modulation switching on-time calculations with reduced mathematical functions. The proposed MLI SVM is derived based on two-level SVM without changing the reference vector position, unlike the traditional approaches. This helps in extending the SVM for any n-level inverter with additional LUTs. The detailed theoretical study, MATLAB-Simulink system generator simulations and Xilinx FPGA family SPARTAN-III-3A based experimental implementations are done with three-level neutral point MLI fed induction motor drive. The theoretical design, analysis, and experimentation results validate the advantages of the proposed PWM design and its implementation. In addition, the proposed implementation is executed from the MATLAB Xilinx system generator directly into target FPGA, which makes it faithful, efficient and minimizes the time spent.

In this research treatise, a novel Calculus Based Unipolar Double Reference Single Carrier PWM (CB-UDR-SC PWM) is proposed for single phase T-Multilevel Inverter (T-MLI) for renewable energy applications. The main downsides of conventional two-level inverters are i) dv/dt of output voltage is high, ii) requirement of fast switching devices, iii) requirement of bulky filter, iv) Electromagnetic Interference is high, iv) temperature of switches is increases with high speed, v) not suitable for high power application and vi) high THD. Single switch with four diodes are used to design the auxiliary structure of T-MLI structure. Total 8 diodes (including anti-parallel diode of switch), five switches are used to design T-MLI for five-level. CB-UDR-SC PWM methodology is proposed by utilizing two modulation signals (derived from calculus) and single carrier. The technique is employed to investigate T-MLI circuitry is for the under-modulation index. The general idea of calculus based PWM is explained in detailed. SPARTAN 3E-XCS250E FPGA trainer kit is utilized to obtain PWM for the switches of T-MLI. Experimental and simulation results are provided which validates the concept and always shows a good agreement with theoretical approaches.

Tracking performance and stability play a major role in observer design for speed estimation purpose in motor drives used in vehicles. It is all the more prevalent at lower speed ranges. There was a need to have a tradeoff between these parameters ensuring the speed bandwidth remains as wide as possible. This work demonstrates an improved static and dynamic performance of a sliding mode state observer used for speed sensorless 3 phase induction motor drive employed in electric vehicles (EVs). The estimated torque is treated as a model disturbance and integrated into the state observer while the error is constrained in the sliding hyperplane. Two state observers with different disturbance handling mechanisms have been designed. Depending on, how they reject disturbances, based on their structure, their performance is studied and analyzed with respect to speed bandwidth, tracking and disturbance handling capability. The proposed observer with superior disturbance handling capabilities is able to provide a wider speed range, which is a main issue in EV. Here, a new dimension of model based design strategy is employed namely the Processor-in-Loop. The concept is validated in a real-time model based design test bench powered by RT-lab. The plant and the controller are built in a Simulink environment and made compatible with real-time blocksets and the system is executed in real-time targets OP4500/OP5600 (Opal-RT). Additionally, the Processor-in-Loop hardware verification is performed by using two adapters, which are used to loop-back analog and digital input and outputs. It is done to include a real-world signal routing between the plant and the controller thereby, ensuring a real-time interaction between the plant and the controller. Results validated portray better disturbance handling, steady state and a dynamic tracking profile, higher speed bandwidth and lesser torque pulsations compared to the conventional observer.

AbstractIn this research work, an adaptive TS‐fuzzy based RBF neural network (ATSFRBFNN) algorithm based maximum power point tracker (MPPT) is employed for grid integrated photovoltaic (PV) system. The novel learning algorithm provides accurate and rapid PV power tracking under fluctuating solar insolation. However, an improved damping circulating current limiting inverter controller is employed to generate gating signal of voltage source inverter and to deliver reduced harmonic constant, less power loss, mitigation of power quality issues regulation of Dc‐link voltage utilization for grid integrated PV system under steady, and transient weather conditions. The experimental results justify the improved system performance under varying operating conditions. The behaviour of novel hybrid PV MPPT structure is compared with TS‐fuzzy, RBFNN, and GA‐RBF for higher tracking efficacy, least tracking deviation, accurate responses, and zero steady‐state power oscillation around MPP region.

Abstract Cascaded H-Bridge (CHB) inverter configuration is most suitable for high power solar inverters. In this work, various energy storage system (ESS) configurations suitable for CHB inverters such as AC side coupled ESS, Dual active bridge based ESS, and buck-chopper and bi-directional chopper based ESS configurations are discussed. Comparison of these configurations on the basis of cost, control complexity, controller hardware requirements are carried out and the advantages of Buck-chopper based ESS systems are listed. Operation and the dynamic response of the buck-chopper based systems are explained in detail with the help of simulation results.