Electrically Excited Synchronous Machines (EESMs) are gaining significant attention in advanced electric drive systems due to their high efficiency, field controllability, and the elimination of rare-earth materials, making them a sustainable alternative to permanent magnet machines. A critical challenge in EESM design lies in achieving reliable and efficient power transfer to the rotor, traditionally managed using slip rings, but rotary transformers (RTs) are increasingly gaining attention due to their contactless operation, enhanced reliability, and reduced maintenance requirements. In this research, a rotary transformer is designed for EESM applications using a machine learning-based surrogate modeling approach. A multi-layer perceptron artificial neural network (MLP-ANN) is trained on simulation data to predict key performance indicators, including efficiency, cost, and hotspot temperature. A multi-objective genetic algorithm is employed to optimize the RT design, aiming to maximize efficiency while minimizing cost. The final design satisfies all constraints and demonstrates the effectiveness of combining neural networks with evolutionary optimization for high-performance, constraint-compliant EESM applications.

Switched reluctance motors (SRMs) are highly regarded for their robustness and simplicity; however, they frequently encounter challenges associated with high torque ripple, significantly impacting their overall performance and efficiency. This paper presents a novel power converter specifically engineered to mitigate this issue by substantially reducing torque ripple in SRMs. The proposed converter incorporates a strategically positioned capacitor to enhance negative voltage discharge during the demagnetisation phase, effectively curtailing negative torque generation. Comparative analysis with the Asymmetric Half-Bridge Converter (AHBC) under lower voltage conditions revealed a slightly elevated torque ripple in the proposed converter’s performance. However, at 250V, it demonstrated a notable 10% reduction in torque ripple, with further enhancements of up to 79% observed at 400V. The results of the experiments mirror the results of the simulations, indicating the performance of the converter in enhancing SRM performance and efficiency. This development represents a significant advancement over traditional converter designs, presenting a compelling solution for the wider adoption of SRM technology.

This paper introduces a novel, compact, and adaptable power converter topology tailored for three-phase Switched Reluctance Motors (SRMs). The proposed converter utilizes five switches, five diodes, and two capacitors, the latter specifically incorporated to alleviate voltage spikes and lessen stress imposed on the lower leg switch. This topology can be categorized as a q+2 configuration, where ‘q’ represents the phase count of the SRM. Engineered with automotive applications in mind, the converter offers salient advantages over the conventional Asymmetric Half Bridge Converter (AHBC), including reduced torque ripple, enhanced demagnetization rates, and improved torque to current ratio. The converter is crafted using Silicon Carbide (SiC) MOSFET power transistors and SiC diodes, and its performance is validated using PLECS simulation software. The inherent flexibility and scalability of the proposed converter make it a viable and efficient solution for a broad spectrum of SRM applications.

This paper introduces a control scheme to improve efficiency as well as both the input and output current ripples of multiphase interleaved buck converter (IBC), which is suitable for applications that require a wide range of output voltage. The number of phases is dynamically changed throughout the entire range of the output voltage in order to obtain the optimum efficiency and the lowest output ripple possible. The paper demonstrates the proposed approach on a single converter of a fast DC charger module which usually consists of multiple converters connected in input-parallel output parallel (IPOP) configuration. Simulation results show that the proposed technique significantly reduces the output current ripple when compared with the conventional phase-shedding technique while maintaining satisfactory high efficiency across the entire range of the output voltage.

An emerging network enhancement, Soft Open Points (SOPs), has been investigated to bring flexibility to the overall Low-Voltage (LV) network. The utilization of Power Electronics Devices (PEDs) in the form of SOP accommodates the increases in load and connected distributed generation (DG), meanwhile supporting grid operations with supplementary functionalities. However, owing to its designated operation and unique topology, there are challenging issues in its practical implementation. This paper investigates the ever-challenging Electro-magnetic Compatibility (EMC) issues resulted from the unbalanced operation of SOP. Two novel approaches have been proposed to tackle the issue. The feasibility and performance of the proposed solutions are verified through mathematical derivations and extensive simulation studies.

In this paper we briefly review the current knowledge on the nonsmooth phenomena in power electronic systems. We describe a method of investigating the stability of nonsmooth limit cycles, and demonstrate its application in investigating the nonsmooth phenomena in the current mode controlled boost converter-which exhibits interesting bifurcations involving tori.

The paper studies the stability of parallel DC/DC converters using the concept of monodromy matrix (the state transition matrix for one complete cycle), whose eigenvalues are the Floquet multipliers. This matrix is composed of the state transition matrices for the smooth intervals and those across the switching events (called saltation matrices). We show that instabilities in this system can be caused by smooth as well as nonsmooth period doubling bifurcations, the latter occurring when the fundamental solution matrix undergoes a discontinuous jump as a periodic solution touches a non-smooth hyper-surface of discontinuity. Based on the expression for the saltation matrices (the state transition matrices across switching events) we propose new controllers that can stabilize the period-1 operation by keeping the eigenvalues inside the unit circle.