Low-Stress and Optimum Design of Boost Converter for Renewable Energy Systems

A Novel Method to Detect Partial Shadow Effects in Perovskite-Based Simulated Solar Cell System Faults

When a fault occurs in photovoltaic systems, a human expert should be present at the scene and perform tests to determine the location and type of the fault. In such a situation, in order to maintain the safety of the specialist, protective measures such as shutting down the power plant or isolating the faulty part are usually taken. Given the fact that the equipment and technology of photovoltaic systems are expensive and their efficiency is currently relatively low (about 20%), a complete shutdown of the plant or part of it can be economical, return on investment and achieve profitability. Therefore, as much as possible, efforts should be made to detect and eliminate errors in the shortest possible time without shutting down the power plant. On the other hand, most solar power plants are located in desert areas, which make them difficult to access and visit. In this case, training skilled manpower and the constant presence of an expert on site can be very costly and uneconomical. Also, if these errors are not detected and fixed in time, they can lead to power loss (not using the maximum potential of the panel), device failure and eventually fire. In this research, using fuzzy detection method, a suitable method for detecting the error of partial shadow occurrence in solar cells is presented. Based on the simulation results, the efficiency of the proposed method is confirmed.

New Multi-Leg Converter for DC Microgrid with Two Duty Cycles

In recent times, important contributions and the incorporation of renewable sources, such as photovoltaic, fuel cells, etc., are the main reasons for the popularity of DC microgrids. Integrating renewable sources into the microgrid requires high-voltage, high-efficiency DC-to-DC converters. Without modification, traditional converters are not suitable for achieving the required voltage in microgrid applications, due to the requirement for a large duty cycle, inductor resistance, voltage rating of switches, reverse recovery of the diode, high current rating inductors, etc. Various converters based on the circuitry of voltage multipliers, switched inductors/capacitors, coupled inductors, transformers, etc., have been proposed in the literature and have their drawbacks. In this paper, to realize significant voltage gain with two duty cycle controls, a new multi-leg (ML) converter is recommended as a solution for use in DC microgrids. The converter is designed by incorporating multiple legs into the boost converter. The implications of the proposed converter are reduced device voltage stress, small inductors and capacitors, two-duty cycle control, triple mode operation, single-stage conversion, etc. The proposed converter’s power circuits, mode of operation, and design equations of the converter are presented. The non-ideal model of the proposed converter is discussed, and efficiency is analyzed. The effect of unequal insurance on the operation of the converter is discussed. Comparative studies of converters are provided to draw attention to the benefits of the converter. The results of the experiments are shown to prove that the analysis and performance of the converter are correct. The discontinuous mode of operation and unequal inductance case of the converter are studied with the help of a simulation model.

Formal synthesis of non-fragile state-feedback digital controllers considering performance requirements for step response

This work describes an approach for synthesizing state-feedback controllers for discrete-time systems, taking into account performance aspects. The proposed methodology is based on counterexample-guided inductive synthesis (CEGIS), producing safe controllers based on step response performance requirements, such as settling time and maximum-overshoot. Controller candidates are generated through constrained optimization based on genetic algorithms. Each iteration that does not satisfy the initial system requirements is learned as a failed result and then used in another attempt. During the verification phase, it is considered the controller fragility to ensure deployable implementations. Such an approach assists the discrete-time control system design since weaknesses occur during implementation on digital platforms, where systems that meet design requirements are employed. The proposed method is implemented in DSVerifier, a tool that uses bounded (and unbounded) model checking based on satisfiability modulo theories. Experimental results showed that our approach is practical and sound regarding the synthesis of discrete state-feedback control systems that present performance requirements. It considers finite word-length effects, unlike other methods that routinely ignore them.