Slavomír Kaščák

This article presents a neural network-based control method for maintaining the required output voltage of a synchronous buck converter. The goal was to replace a traditional PID controller with a neural network that calculates the duty cycle based on real-time data. Several versions of the neural network were tested. The final version, which included the input voltage, reference, and output current as inputs and compensated for dead time, was successfully validated on real hardware. It was able to respond to changes in load and input voltage within a limited operating range.

This article presents the design and development of a supercapacitor for defined power profiles, focusing on the selection process for an optimal supercapacitor to form a high-performance supercapacitor module. The study outlines the methodology for selecting suitable components based on energy and power density requirements, considering operational efficiency and durability under specific load conditions. A control algorithm for bidirectional power flow is developed to regulate the charging and discharging processes of the supercapacitor module, ensuring efficient energy management. Practical verification of the designed SC module is performed to evaluate the system dynamic response under various operational scenarios. The practical experimentation using the supercapacitor module is tested in laboratory conditions. The experimental results demonstrate the effectiveness of the control strategy in achieving bidirectional operation, confirming the suitability of the designed supercapacitor module for applications requiring fast power delivery and recovery.

Battery storage systems are becoming very popular around the world. However, they are mainly used in industry for high-performance applications. Domestic use is still sporadic due to size and cost issues. This work overviews basic conceptual designs for a cost-effective battery storage system. The main specificity of the proposed systems is the use of commonly available recycled batteries from household appliances such as laptops and backup power supplies. The circuit topology considered is a 3S (three cells in series) configuration. This is because such wiring arrangements are those that are most often found in the home appliances described here. The technical solutions of the device itself focus on the ratio of the efficiency of the whole system to the production cost. Given the above, attention was paid to the simulation analysis of the operating modes, which directly influenced the components’ price. Changing the switching control scheme of the power transistors makes it possible to reduce the requirements for the driving components used with minimal impact on the power conversion efficiency (Δη 1–4%). According to the established findings, a prototype was made on which the simulation findings were verified; then, we further focused on the experimental measurement of the efficiency of the MPPT converter and conducted an analysis of a methodology in which we measure the deviation from the actual point of maximum power. The simple possibility of parallelizing the individual storage devices will again help improve the system’s overall efficiency. This makes the system suitable for use in small spaces such as houses, garages, cellars, etc.

The paper presents the practical design and implementation of a three-level neutral point clamped (TNPC) six-phase inverter rated at 100 kVA. The study initiates with prior work review, whereby most research work done earlier was mainly simulation-based. Based on the simulation results, this paper focuses on the practical aspects of inverter design, such as the development of a power board on an Insulated Metal Substrate, a gate driver board, an interconnect board, and the main control board. An inverter physical prototype has been built and tested at 500 V and 20 kW of output power. The SiC semiconductor technology is the base of the inverter, which represents the main merit of the work. Finally, high power density, compact design, and high efficiency are shown, which are major contributions of the paper. Tests performed proved that the designed converter was operating reliably and efficiently. While a simple Sinusoidal Pulse Width Modulation (SPWM) control algorithm has been implemented, the overall performance of the inverter showed great promise for higher-power applications. Compact and high-efficiency TNPC converters are developed for meeting increasing demands of advanced energy, automotive, and industrial applications.

This paper presents an approach to designing a supercapacitor (SC) module according to defined power profiles and providing a control algorithm for sharing the energy from the SC module and accumulator in a hybrid energy storage system (HESS). This paper also presents a view of a printed circuit board (PCB) of the SC module and an interconnection board between the bidirectional converter, accumulator, and SC module. The practical part of the paper presents the measurement of the voltages and currents on the SC module, accumulator, and output of the DC/DC converter to visualize the energy flow between them.

This paper deals with the quasi-instantaneous determination (in a single-step response time) of apparent, active, and reactive (i.e., blind and distortion) power mean values including the total power factor, total harmonic distortion, and phase shift of fundamentals of a power electronic and electrical system (PEES) using the ip-iq method, which is the main contribution of the paper. The power components’ mean values are investigated during the transient and steady states. The power components’ mean values can be determined directly from phase current and voltage quantities, using an integral calculus over one period within the next calculation step and using moving average and moving rms techniques (or digital filtering). Consequently, the power factor can be evaluated with known values of a phase shift of fundamentals (using a Fourier analysis). The results of this study show how a distortion power component during transients is generated even under a harmonic supply and linear resistive–inductive load. The paper contains a theoretical base, modeling, and simulation for the three and single phases of the transients in power electronic systems. The worked-out results can be used to determine and size any PES. The presented approach brings a detailed time waveform verified by simulations in Matlab/Simulink 2022a and the Real-time HW Simulator Plecs RT Box 1.

The popularity of multiphase drives is increasing due to the growing interest in drives with more than three phases. One promising topology is the multiphase matrix converters, which enable the implementation of a single-stage AC/AC power conversion system with bidirectional power flow capability. In this paper, we present the implementation of indirect control for a practical sample of the direct matrix converter. To reduce the overall cost of the control solution for these types of converters, we utilized low-cost FPGA and DSP. The usage of only DSP itself was not possible due to low number of available PWM output needed for 3 × 5 MxC driving. Another reason is commutation, which must be precise and fast to avoid any hazardous states in the converter. Due to these problems, the authors decided to implement an algorithm of a combination of DSP and FPGA, where FPGA is used for time critical operations. The indirect algorithm treats the converter as two separate parts, the rectifier and the inverter, with the DC-LINK being fictitious. The matrix converter is composed of compact modules, and the entire system is verified. The practical verification demonstrates that matrix converters can produce a wide range of output frequencies and achieve input power factor control. Finally, we compare and review the practical model with the simulation model, examining efficiency and other parameters.

This article addressed the problem of matrix converters (MxC), specifically the investigation of power losses and matrix converter efficiency in a 3 × 5 arrangement. In today’s modern world, efficiency is very important; hence, power loss and efficiency analysis are important throughout the design process of modern semiconductor converters. The ability to evaluate power losses more quickly using the simulation approach can greatly reduce the amount of time necessary for the design, in comparison with numerical analysis. The described model employed contemporary SiC semiconductors, which offer substantial benefits over IGBT transistors. The 3 × 5 converter model was shown, along with a study of power losses in various elements of the converter, such as the power circuit, input filter, and so on. A summary of the simulated findings was offered at the end of the study, along with the benefits and drawbacks of employing SiC semiconductors in bidirectional switches for matrix converters.