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.

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.

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

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.

This article presents a paper-based Tangible User Interface (TUI) that facilitates the production of complex queries on a Cultural Heritage (CH) repository. The system helps to easily make use of the data elements and Boolean logic that describe the collections. This research presents a design methodology divided into two main phases: A User Experience (UX) and User Centred Design (UCD) where potential users' behaviours are analysed, followed by the development and evaluation of the TUI prototype. The TUI uses off the shelf electronics and a paper-based set of tokens to engage the user with the system, thus facilitating the exploration with CH collections through querying.

DC-AC conversion has been revolutionized by multi-level converters due to their high power quality, high modularity and high voltage operation with standard semiconductors. New multilevel topologies, voltage asymmetries and control techniques have been developed in the last decade to improve the performance of these power converters. This paper proposes a novel voltage asymmetry for a three-phase cascaded multilevel converter based on cross-connected half-bridge cells. The proposed asymmetry is compared with the state-of-the-art asymmetry in the same topology and with several asymmetries and topologies as the conventional Cascaded H-Bridge (CHB), the Asymmetric Cascaded H-Bridge (ACHB) and the Neutral Point Clamped (NPC). This paper presents a comparison and analysis of voltage levels generated, the number of IGBTs and isolated voltage supplies required. Simulation results are presented for a converter of 11 kV and 4 MVA. The proposed configuration increase the number of voltage levels in three-phase loads, reducing the Total Harmonic Distortion (THD) under 1%. On the other hand, the total blocking voltage was not reduced, but the number of isolated power sources required for the proposed topology is very low in comparison with other topologies.

DC to AC conversion technology has succeeded in obtaining high power quality (voltages and currents) using multilevel inverters. These inverters can generate several levels of voltage that reduce the harmonic distortion of the generated sine waves in the AC side. However, the output voltages always are discrete, so a non-negligible harmonic distortion remains. This distortion can be reduced by increasing the number of voltage levels generated by the multilevel inverter, but this means reduce the reliability and increase the number of semiconductors. This paper proposes a novel continuous space vector modulation (C-SVM) that generates continuous AC voltages without using filters and reduces the total harmonic distortion (THD) of the voltage under 1%. This proposed modulation requires two variable power sources (e.g. buck converters) but can be implemented in simplified three-phase cascaded multilevel converters. Moreover, this continuous modulation allows the implementation of a novel cascaded multilevel inverter with a reduced topology. Simulated results show the proposed space vector modulation and the output voltage and currents obtained in inductive loads and in an induction motor.