This paper addresses the challenges of selecting a suitable method for negative temperature coefficient (NTC) thermistor-based temperature measurement in electronic devices. Although measurement accuracy is of great importance, the temperature calculation time represents an even greater challenge since it is inherently constrained by the control algorithm executed in the microcontroller (MCU). Firstly, a simple signal conditioning circuit with the NTC thermistor is introduced, resulting in a temperature-dependent voltage U_T being connected to the MCU’s analog input. Next, a simulation-based approximation of the actual temperature vs. voltage curve is derived, resulting in four temperature notations: for a look-up table principle, polynomial approximation, B equation and Steinhart–Hart equation. Within the simulation results, the expected temperature error of individual methods is calculated, whereas in the experimental part, performed on a DC/DC converter prototype, required prework and available MCU resources are evaluated. In terms of expected accuracy, the look-up table and the Steinhart–Hart equation offer superior results over the polynomial approximation and B equation, especially in the nominal temperature range of the NTC thermistor. However, in terms of required prework, the look-up table is inferior compared to the Steinhart–Hart equation, despite the latter having far more complex mathematical functions, affecting the overall MCU algorithm execution time significantly.

This paper presents a method for the detection of broken rotor bars in an induction motor. After introducing a simplified dynamic model of an induction motor with broken cage bars in a rotor field reference frame which allows for observation of its internal states, a fault detection algorithm is proposed. Two different motor estimation models are used, and the difference between their rotor flux angles is extracted. A particular frequency component in this signal appears only in the case of broken rotor bars. Consequently, the proposed algorithm is robust enough to load oscillations and/or machine temperature change, and also indicates the fault severity. The method has been verified at different operating points by simulations as well as experimentally. The fault detection is reliable even in cases where traditional methods give ambiguous verdicts.

The paper presents a comprehensive overview of recent advancements in power electronics and electric machine design, focusing on novel topologies, semiconductor technologies, and integrated design techniques for electric drives. New drive topologies are gradually moving from the research phase to practical application, aiming to increase the rated power, efficiency, and reliability of electric drives. Specifically, these topologies can be categorized into series, which focus on increasing the operating voltage; parallel, which aim at enhancing the operating current and adding redundancy; and multiphase, known for offering significant benefits such as improved fault tolerance, higher torque generation, the possibility of synthetic loading, and diverse winding layout options. Emerging wide bandgap semiconductors, such as silicon carbide and gallium nitride, allow for operation at higher frequencies and lower power losses, enabling further drive integration. In terms of design practices, higher computational power, supported by advanced software, enables simulation and analysis in multiple domains (thermal, mechanical, electromagnetic) using multiphysics co-simulation, as well as multi-objective optimization concepts to achieve rapid prototyping of optimized drive systems. All the approaches described are important steps towards further improving electric drives for numerous applications in industry, consumer electronics, and transportation.

In industrial applications, the reliable performance of induction motors (IM) is essential. This paper proposes an improved method to distinguish between broken rotor bar (BRB) faults and load oscillations (LO) by analyzing stator current components in the rotor-flux reference frame. The approach employs a diagnostic fault indicator based on the amplitude ratio of current oscillations in the direct and quadrature axes, with a threshold established through simulation data and a support vector classifier (SVC). If the detected spectral peak pair corresponds to a BRB, the fault indicator exceeds the threshold. Conversely, peaks caused by LO result in an indicator value significantly below this threshold. The explicit and unambiguous separation between BRB and LO effects allows for the practical recommendation of a unity threshold. Simulations and experimental results validate the method’s robustness, demonstrating accurate fault identification even under challenging conditions, such as lightly loaded motors with a single BRB. The method relies solely on current and voltage measurements, avoiding the need for speed sensors. With low computational demands, it integrates seamlessly into existing motor drive systems. These features make it a practical and cost-effective tool for real-time fault detection and predictive maintenance in industrial settings.

The interleaved buck converter with an extended duty cycle is analyzed in terms of unexplored parasitic switching states that diminish the switch utilization and its safety due to high-magnitude charging and discharging currents. The analysis explains the origin of the states and their effects and demonstrates their correlation with the existing voltage ripple on flying capacitors. The article further demonstrates that the voltage ripple can no longer be arbitrarily chosen as parasitic states emerge whenever the ripple exceeds an identified critical value being equal to the twofold voltage drop on the diode. A simple design criterion for flying capacitance is proposed. For a limited set of battery-powered DC–DC converters, a solution permitting the use of smaller capacitance by adding an extra switch is proposed. The derived findings are verified using experimental and simulation results.

In this paper, we analyze the constraints of harmonics control in power electronic systems. Based on an equivalent circuit of a typical power converter application and its parameters, we have derived an analytical expression for calculating the maximal amplitude of controlled harmonic current. This expression has been successfully verified on an experimental setup, designed around a single-phase grid-connected bidirectional inverter. The pulse width modulated (PWM) driven inverter has been controlled by multiple resonant controllers, each of them providing individual control of a selected harmonic current. By using the derived expression and taking into account the parameters of converter application, power electronics designers could quickly determine the limitations of harmonics control.