Ajmal Farooq

In this paper, a new topology of a step-up DC converter is presented for renewable energy applications, yielding a high step-up conversion ratio and reduced voltage stress across the switches. The proposed converter uses a hybrid switched-inductor and switched-capacitor cell to achieve the high voltage gain. Additionally, the capacitors in the switched cell also perform the function of clamping the voltage across switches. The proposed converter utilizes only a single controlled switch and operates in only two modes of conduction. The steady-state analysis and operating principle of the proposed hybrid step-up converter are discussed in detail and various mathematical equations have been derived. The analysis shows numerous improvements over the traditional DC-DC converters. Simulation was carried out in MATLAB Simulink 2021b on a 55% duty cycle and simulation results are compared with theoretical analysis. From simulation results, it is clear the proposed converter exhibits better performance compared to conventional boost and other traditional step-up converters with the same design parameters. Finally, a 31.5-watt hardware prototype was constructed and tested in the laboratory to experimentally validate the theoretical and simulation results.

The main aim of this study is the development of a fast and secure charging system for electric vehicles. Recently, many different charging methods have been introduced. The main charging methods are the induction charging method and the conduction charging method. In this paper, the conduction charging method is employed. With regard to the conduction method, there are three levels of charging. At level 1, there is single-phase charging, while both single-phase and three-phase charging occur at level 2. Lastly, at level 3, a three-phase AC charging method, DC conduction charging method, and AC/DC conduction charging method is focused. The level 3 charging method is the main focus of this paper. Toward this end, a 12-diode rectifier or 12-pulse rectifier with a firing angle of zero degrees having two bridges is used for AC to DC conversion, while a SEPIC converter is used for DC-to-DC conversion. The design presented in this paper was simulated and verified using MATLAB/Simulink, and the results show that the Total Harmonic Distortion (THD) of the input current was reduced, and that overall efficiency was improved.

Modular multilevel converters (MMCs) have been conceived as an alternative in front-end converter applications to enhance the converter system’s reliability, minimize total harmonic distortion, and improve power quality. These converters utilize several DC-link capacitors and power electronic switches, along with switches operating with high switching frequencies, to attain the desired characteristics. Thereby, this paper systematically proposes a novel three-phase asymmetric hybrid modular multilevel converter (AHMMC) for front-end converters used in lower-medium-voltage applications. The AHMMC configuration is based on a three-phase converter connected to a per-phase series arrangement with a cascaded converter module (CCM). The study investigates the AHMMC and proposes a control scheme, which minimizes the voltage range on switches and maintains the current to its reference value. Furthermore, the study also introduces an active balancing of voltage across DC-link capacitors based on the phase opposition disposition PWM (POD-PWM) method. Our new configuration has features such as low switching loss, reduced DC-link voltage, a wider modulation range for the unity power factor (PF), and low voltage and current harmonic distortion. The simulation results are added to verify the performance of the new AHMMC topology and the usefulness of the modular control scheme. In addition, a low-voltage laboratory prototype based on customized control and power boards is built to validate the proposed converter and its control scheme in practice.

This paper proposes a hybrid control scheme for a newly devised hybrid multilevel inverter (HMLI) topology. The circuit configuration of HMLI is comprised of a cascaded converter module (CCM), connected in series with an H-bridge converter. Initially, a finite set model predictive control (FS-MPC) is adopted as a control scheme, and theoretical analysis is carried out in MATLAB/Simulink. Later, in the real-time implementation of the HMLI topology, a hybrid control scheme which is a variant of the FS-MPC method has been proposed. The proposed control method is computationally efficient and therefore has been employed to the HMLI topology to mitigate the high-frequency switching limitation of the conventional MPC. Moreover, a comparative analysis is carried to illustrate the advantages of the proposed work that includes low switching losses, higher efficiency, and improved total harmonic distortion (THD) in output current. The inverter topology and stability of the proposed control method have been validated through simulation results in MATLAB/Simulink environment. Experimental results via low-voltage laboratory prototype have been added and compared to realize the study in practice.

In an attempt to meet the global demand, renewable energy systems (RES) have gained an interest in it due to the availability of the resources, especially solar photovoltaic system that has been an importance since many years because of per watt cost reduction, improvement in efficiency, and abundant availability. Photovoltaic system in remote and rural areas is very useful where a grid supply is unavailable. In this scenario, power electronic converters are an integral part of the renewable energy systems particularly for electronic devices which are operated from renewable energy sources and energy storage system (fuel cell and batteries). In this article, a new topology of charge pump capacitor (CPC) which is based on high voltage gain technique DC-DC boost converter (DCBC) with dynamic modeling is proposed. To testify the efficacy of the introduced topology, a prototype has been developed in a laboratory, where input was given 10VDC and 80VDC output voltage achieved at the load side. Furthermore, the experimental result shows that the voltage stress of MOSFET switches is very less in comparison with the conventional boost converter with the same parameters as the proposed converter.

In this paper, an active power filter (APF) based on a modified one-cycle control is proposed. This control method can be applied in a three-level three-phase four-wire system. By adding an additional current sensor to detect the fundamental component of the output current, the proposed APF is capable of compensating harmonic components independently from the VAR compensation so that the capacity of APF can be greatly reduced. The viability of the proposed scheme is verified by performing experimental validation.