Wireless Power Transfer (WPT) is an emerging technology that enables energy transfer without physical contact. One of the main challenges in its practical implementation is achieving high material efficiency relative to the power transferred. This work proposes a novel high-power-density multiphase coil architecture that integrates the LCC filter inductors directly into the transmitting system, thereby eliminating the need for additional ferrite cores and reducing conductor length. Unlike previous approaches, this proposal leverages both the spatial and phase alignment of multiphase coils to achieve a constructive superposition of the resulting rotating magnetic field. Electrical and magnetic models of the proposed system were developed, along with time and frequency domain simulations, enabling the analysis of system stability and magnetic field gain. The results show that inductor integration does not negatively impact field shape or system efficiency, while significantly reducing material usage and maintaining high power transfer capability. This proposal lays the foundation for the design of more compact and material-efficient multiphase WPT systems.

Offline generation of Selective Harmonic Control PWM (SHC-PWM) solutions for Active Power Filters (APFs) presents a significant computational burden, particularly for extensive operating ranges. This paper proposes an efficient hybrid algorithm combining Differential Evolution (DE) and Nelder-Mead (NM) within a hierarchical framework to drastically accelerate this offline computation. The proposed method minimizes computationally intensive global optimization by adaptively employing fast local search, initialized with previously computed solutions, achieving smooth parameter variations. Achieving speedups greater than 100x compared to other hybrid methods, the algorithm successfully generated millions of unique SHC-PWM solutions averaging 0.07 seconds per point using a standard Intel Core Laptop. APF simulations using the generated data validated effective compensation for controlled current harmonics greater than 99.5%. This work enables the practical generation of large datasets required for advanced SHC-PWM strategies.

Modular Multilevel Cascade Converter (MMCC) have gained wide-spread acceptance in high voltage converter applications. As they require a high amount of capacitors whose voltages must be known for the control of the MMCC, many voltage sensors are needed. This paper proposes the application and the efficient implementation of fixed-point recurrent neural network (fpRNN) based observers for cell voltage estimation of chopper and bridge cells. The proposed observers are capable of learning from data to adjust the estimation model despite its intrinsic nonlinear behavior and unmodeled parasitic effects. The performance of the observer is validated against high-fidelity PLECS simulations. Moreover, the achievable estimation accuracy of different fpRNN observer implementations is compared depending on the utilized fixed-point number format.

This paper presents an adaptive selective harmonic elimination based on artificial neural networks (ASHE-ANN) with indirect model-based online training. The strategy builds on the established analytical formulation of Selective Harmonic Elimination (SHE) to derive a relationship between the magnitudes and phase angles of the Fourier Transform (FT) spectrum and the switching angles, along with their respective error gradients. This relationship enables online training of the artificial neural network (ANN) to dynamically adjust switching angles in real time, achieving precise control of the fundamental voltage magnitude while eliminating target harmonics. Compared to conventional SHE implementations that rely on precomputed lookup tables (LUTs), the proposed approach demonstrates enhanced harmonic suppression under nonideal DC-link conditions (e.g., voltage fluctuations, unbalanced sources). The results highlight the adaptability of the ASHE-ANN strategy in dynamic scenarios, offering an alternative to static LUT-based methods.

Energy balancing is a key control objective in Modular Multilevel Cascaded Converters (MMCCs). Conventional approaches often rely on predefined assumptions about grid voltage and current to analyze capacitor voltage oscillations and establish a desired steady-state waveform. This work proposes a novel control strategy for Inter-Cluster Balancing (ICB) that operates solely based on real-time measurements, eliminating the need for predefined waveforms. The proposed method is derived from instantaneous power theory, enabling a self-regulating balancing mechanism that adapts dynamically to operating conditions. Its effectiveness is validated through simulations of a grid-connected Static Synchronous Compensator (STATCOM), employing a down-scaled Delta-Connected Cascaded H-Bridge Converter to replicate real-world operating conditions.

The Dual-Star Chopper-Cell (DSCC) Modular Multilevel Converter (MMC) has emerged as one of the most attractive topologies for medium-voltage (MV) AC/DC applications due to its modularity, scalability, redundancy, and high-power quality. In this voltage range, the 2N +1 Optimal Pulse Pattern (OPP) has been used in MMCs due to its low switching frequency and good quality signal on the AC side. However, the DC part of the MMC has not been equally studied, resulting in a high current ripple on the DC side. This paper proposes a method to reduce the current ripple of the DC side current without hardware changes or increased switching frequency by adding constraints to the 2N + 1 OPP problem; the proposed constraints limit the DC side current by reducing the duration of the redundant states. The proposed method is validated by simulations of a DSCC-MMC with nine cells per arm and a reduction in the ripple of the DC side current up to approximately 27% with respect to the problem without the proposed constraints.

This article introduces a power decoupling method for a Triple Active Bridge (TAB) converter, utilizing Penta-Phase Shift modulation (PPS) and an optimization approach that minimizes conduction losses. The resulting optimal solutions are stored in a Look-Up table (LUT), the outputs are the optimal phases and duty cycles in a TAB converter to meet power constraints. Additionally, Proportional-Integrative and Resonant (PI and PR) controllers adjust the output of the Look-Up Table to ensure zero power steady-state error while effectively eliminating low-frequency power oscillations. This method not only eliminates low-frequency oscillations in total power transfer, but also allows for the use of smaller capacitors, facilitates the implementation of a high-efficiency Maximum Power Point Tracking (MPPT) algorithm in PV applications, and reduces both the size and losses in the High-Frequency Transformer (HFT).1

This article introduces a new method for mitigating low frequency power oscillations in a Quad Active Bridge (QAB) converter. This is achieved by using GHA-based frequency-domain modeling of the QAB to obtain an equivalent model that considers Hepta Phase Shift (Hep-PS) modulation, utilizing all seven degrees of control possible in the QAB. The model is used in the creation of an optimization problem with a conduction loss minimization approach, which generates optimal solutions of the seven degrees of control (duty cycles and phases) for multiple operating points (port voltages and transfer powers). The results are stored in a look-up table (LUT). The control and modulation are validated in a PLECS simulation, achieving equal and different power flows in an asymmetrical QAB connected to variable voltage primary ports and a single fixed voltage secondary port. The presented method optimizes converter efficiency by minimizing conduction losses, allows the use of smaller capacitors, and helps to prevent saturation of the HFT while reducing its size and losses.

Back-To-Back Modular Multilevel Converter (BTB MMC) was proposed as an attractive alternative for medium-voltage drive application to decrease the inherent problem of high floating capacitor voltage fluctuations produced at low frequency machine operation. Recently the variation of DC-Link reference between the MMC and a control strategy based in control the machine side MMC as a current source was introduced to decrease the mitigation variables using during low frequency operation. However, it does not solve the problem to obtain the minimal capacitor voltage fluctuation during the entire machine operation. This paper propose a new method to obtain the minimum capacitor voltage fluctuation of the MMC modules during the entire machine operation range including an additional AC signal between the system common link. The proposed control strategy and overall performance of the system are verified by computational simulation.

The Modular Multilevel Matrix Converter (M3C), also known as Triple Star Bridge Cells (TSBC) converter from the family of Modular Multilevel Cascade Converter (MMCC) has attracted attention in medium/high voltage, high power applications. Recent research has identified its potential for various direct high power AC/AC conversion applications due to its modularity, redundancy and high power quality. However, it suffers from cross-coupling while utilising low/fundamental frequency switching techniques such as Nearest Level Control (NLC) along with the double αβo transformation. This article proposes a decoupling approach to eliminate the coupling effect and low frequency oscillation at the output port for implementation of NLC in an MMCC-TSBC converter.

In this work a dynamic control of the dc-link voltage in a hybrid Back-to-Back (BtB) Modular Multilevel Converter for medium-voltage drive applications is presented. The proposed control scheme relates the speed of the machine with the dc-link voltage magnitude to reduce the large circulating currents and common-mode voltage of the converter when the machine operates at low speed. Simulation results, performed in the software PLECS, validate the model of the BtB converter and the proposed control scheme, reducing circulating currents and common mode voltage in almost 70% and 60% respectively, when the machine operates at very low speed.

Phase-Shifted Modulation (PSM) applied to multilevel converters is an effective method for reducing the output THD. In this paper, a new unipolar PSM method is proposed to control internal circulating current of a high-current low-voltage power converter, composed of parallel connected H- Bridges. The proposed method reduces the H-bridge currents distortions and the power losses of the overall converter. Simulation results comparing the standard unipolar modulation with the proposed unipolar modulation technique are performed to demonstrate its effectiveness.

In this paper control systems suitable for a 4-leg NPC converter are discussed. The proposed control methodology is based on a finite set model predictive control. A theoretical analysis of the strategy, including tracking of non-sinusoidal currents and reduction of the switching frequency, is presented in this paper and experimental results, obtained with a 3 kw experimental prototype are discussed.