System reliability represents a fundamental aspect in power converter operation. Within the spectrum of critical components, semiconductor devices and capacitors stand out as the most significant elements. This research examines the implementation of diverse pulse-width modulation (PWM) strategies within two-level voltage source inverters (VSI), with emphasis on both continuous and discontinuous modulation approaches. These methodologies are assessed regarding their influence on system efficiency and harmonic-related losses within the DC-link capacitor. The investigation encompasses essential operational variables including switching frequency, apparent power, and power factor. This work seeks to determine which modulation strategy provides optimal performance for capacitor loss reduction and to establish the most suitable technique based on specific application demands.

This paper presents the design, implementation, and comparative analysis of three current control strategies for a 0.2 MW three-phase Neutral Point Piloted (NPP) T-type inverter connected to the grid. The study compares Proportional–Integral (PI) controller, a first-order Sliding Mode Controller (SMC), and a Pseudo–Second–Order Super–Twisting Sliding Mode Controller (STSMC), all applied to the inner current control loop. The inverter is modeled with an RL output filter for current shaping and grid interfacing. While PI controllers offer simplicity, they suffer from limited disturbance rejection and tracking performance. Classical SMC improves robustness but introduces chattering. The proposed STSMC reduces chattering while preserving the benefits of SMC. Simulation results in MATLAB/Simulink assess each controller’s performance in terms of power injection and harmonic compliance with IEEE 519. The study highlights the superior transient and steady-state behavior of higher-order SMC methods.

This paper presents a real-time predictive control strategy aimed at maximizing energy self-sufficiency in an industrial microgrid integrating photovoltaic (PV) generation, lithium-ion battery storage, and bidirectional electric vehicles, using the paradigm of Vehicle to Grid (V2G). The proposed Economic Model Predictive Control (EMPC) framework leverages forecasts of solar production, load demand, and vehicle availability to optimize energy flows over a prediction horizon. The control architecture relies on a real-time implementation using industrial-grade hardware, with a layered structure combining a programmable logic controller (PLC) and a Python-based optimization environment. The system is experimentally validated on a testbench equipped with real power converters and programmable loads. Results demonstrate that the integration of V2G enhances the flexibility and autonomy of the microgrid, enabling reduced dependence on the external grid and improved use of renewable resources. The proposed approach contributes to the development of resilient and intelligent energy systems for industrial applications.

Dual Active Bridge (DAB) converters have emerged as a leading solution for industrial applications that require high efficiency and bidirectional power transfer with isolation. The Triple-Phase-Shift (TPS) modulation scheme enables flexibility to enhance efficiency by choosing the operating point that minimizes power losses. This paper presents a novel, simplified methodology for reducing conduction losses in DAB converters using polynomial-based techniques. The operation of the DAB converter under TPS modulation is analyzed, and the corresponding modeling equations are derived. The proposed optimization method is described and validated through simulations in various design scenarios. The results demonstrate the existence of a set of three polynomials that effectively minimize the rms current based on the load conditions and the voltage ratio. Preliminary findings show that these polynomials will remain nearly constant across different converter designs, provided the output-to-input voltage ratio is the same.

Electric vehicle (EV) charging infrastructure is critical, especially considering the exponential increase in electric vehicle adoption over the last decade, leading to a surge in demand for charging stations. However, it is not just about increasing their number; consideration should also be given to the reliability and availability of these chargers. Several factors can affect power converter reliability, many of which have been studied independently of the application. Nevertheless, in addition to those EV chargers are subjected to unique controls and operation that depend on the different battery charging profiles that have been proposed. This work analyzes the impact of different load profiles on semiconductors, using a total of four different load profile strategies. The results show that there is a very similar impact on damage among the most mainstream charging profiles. However, the Pulse Charging (PC) profile stands out as one that accumulates more semiconductor damage, reducing EV charger reliability.

Electromobility has experienced rapid expansion, where electric vehicle (EV) battery and charging processes are of great importance. Charging profiles have been proposed to enhance charging speeds while improving battery lifetime. However, more research is needed in relation to their impact on the charging infrastructure. This paper analyzes the impact of the charging profile over the global efficiency of the power converter of the fast charging station. Both full and partial charges are considered, and four types of charging profiles and variants, for a total of 12 charging profiles are considered. Results of this study show significant efficiency differences depending on the charging profile, being the classical Constant Current Constant Voltage (CCCV) at low charging rate the most efficient charging profile, while Pulse Charging (PC) leads to the lowest. The dependence of the global efficiency of the power converter with the corresponding charging time is also analyzed.

In this article, an efficient and flexible communication schema for on-chip and off-chip communication is presented. With a reduced header size, the proposal can achieve high communication efficiency among the devices of a distributed static network or the internal components in a system-on-chip. In addition, the proposal is very versatile in terms of network configurations and topologies. An FPGA implementation of the proposal has been developed and thoroughly verified, both in simulation and when implemented in two different FPGA devices. The prototypes are exhibiting good results which validate the expected performance, with an efficient use of device resources. As a result, the proposed schema can both improve existing applications whose performance is affected by communication overhead and enable new industrial applications that require efficient communications in distributed static networks.

In this article, on the basis of an existing dual layer nested (DLN) adaptive sliding-mode control (ASMC) strategy, an observer-based sliding-mode control strategy with an improved DLN adaptive tuning mechanism (IDLN-ASMC) is proposed for a three-level neutral-point-clamped converter. The proposed controller not only ensures good system performance but also mitigates two problems of the existing DLN-ASMC strategy. Meanwhile, three objectives are achieved. First, an adaptive supertwisting algorithm is utilized in the power tracking loop to converge power tracking errors to bounded regions in finite time. Next, a disturbance observer-based IDLN-ASMC strategy is proposed in the dc-link voltage regulation loop to regulate the dc-link voltage to its reference value. Finally, a simple proportional-integral controller is used in the dc-link voltage-balancing loop to reduce the voltage difference between the two dc-link capacitors. The results of simulation and experiment demonstrate the effectiveness and superiority of the proposed strategy.

Phase-shifted pulse width modulation (PS-PWM) is one of the preferred modulation strategies for cascaded H-bridge (CHB) converters due to its excellent harmonic performance. Nevertheless, this modulation strategy needs a fast sampling frequency, which can increase with the number of H-bridge sub-modules (SMs). Moreover, the advantages related to the harmonic content of the output voltages are usually lost for applications that require unbalanced operation conditions regarding SM power or voltage references, such as solar PV or battery energy storage systems. This work proposes a feed-forward compensation technique that reduces the sampling frequency to two times the carrier frequency while maintaining the good harmonic performance of the CHB output voltages. Simulation results are carried out to compare and demonstrate the superior performance of the proposed technique.

In this article, a linear extended state observer (LESO) based second-order sliding mode (SOSM) control strategy with the direct power control is proposed for a three-phase neutral-point-clamped (NPC) power converter connected to a dc microgrid. Comparing with the PI control method, the proposed approach implements the advanced SOSM controller into the voltage regulation loop and instantaneous power tracking loop to enhance the dynamic and steady state performance. Furthermore, saturation function is applied in the SOSM method to weaken the chattering phenomenon. On the other hand, since the dc load is regarded as an external disturbance, an efficient LESO is designed in the voltage regulation loop to reject this disturbance. The design process of the proposed control strategy is shown based on the continuous averaged model of the NPC converter. Finally, comparison experiments among PI, LESO-based PI, and proposed LESO-based SOSM control strategies are implemented, which validate the superiority of the proposed approach.

In Electric Vehicle (EV) application, the in-wheel motors are driven by the same dc-link voltage. To reduce the space, the Voltage Source Inverters (VSIs) can share one dc-link capacitor. Long-term experiences and experimental data demonstrate that the capacitors are one of the major failures in the motor drive system. The current profile of the dc-link capacitors is the main factor for this degradation, therefore, by reducing the current harmonic components of the dc-link capacitors can increase the lifetime. In this paper, a dc-link capacitor current harmonic reduction method for dual Permanent Magnet Synchronous Motor (PMSM) drive system in EV application is proposed. The Phase Shift Pulse Width Modulation (PSPWM) is employed in the dual inverters to reduce the harmonic components of dc-link capacitor. To verify the proposed method, a experimental platform is established and the experimental results are presented.

Reduction of switching losses in power converters is especially important for very high power applications looking for improving the reliability and efficiency. In contrast to carrier-based modulations, selective harmonic elimination and mitigation techniques use optimal waveform computation to generate a fundamental component while managing voltage harmonic content. However, these techniques, and specially selective harmonic mitigation, impose a high non-linear set of expressions to be solved. Therefore, complexity and computational burden rise up. Meta-heuristic algorithms are commonly used to solve the mathematical optimization problem involved. Preliminary application of Exchange Market Algorithm for harmonic mitigation problem has already been presented. However, in this paper a redefinition of the optimization is proposed to consider harmonic content for a wider range of frequencies. Results from computation for a wide range of modulation index are presented.

Nowadays, the design of power converters has been focused on the optimization in terms of reliability, fault-tolerant capability and power density. The use of modular converters leads to natural fault-tolerant capability because the power system can be still operating even when some module has failed. In this paper, the reliability of modular converters, which is high-dependent of several factors like as thermal stress, is studied. In the paper, the power devices aging of dc/dc interleaved power converters is managed. The proposed method is based on sharing conveniently the total managed power between the power modules. This can be done without losing performance in the power system. The proposed power routing technique has been tested in a three-module interleaved boost converter which is used in multiple applications.

This paper proposes an effective method to control the modular multilevel converters (MMC). The whole control scheme can be divided into three stages. Firstly, the prediction technique is employed to derive a quadratic programming problem from a cost function, leading to the voltage reference for each arm of the MMC. Secondly, the simple nearest level control is adopted to get the number of on-state SMs for each arm. At last, within each arm the submodules (SMs) are selected based on the sorting results of their capacitor voltages. Simulation based on a three-phase grid connected MMC system is conducted to evaluate the effectiveness of the proposed method. The results show that the proposed technique is capable of tracking the output current reference with very low distortion, while the SM capacitor voltages are well balanced and the circulating currents are almost suppressed. The transient response is fast and accurate as well.

An efficient modulation stage is required for power conversion to achieve a good performance fulfilling the requirements of output filtering. On a high competitive market, the ability to adjust output harmonic content beforehand is required to adapt to a wide range of operating conditions. For this purpose, selective harmonic mitigation (SHM) is a very attractive solution for high-power applications because of its versatility and ease to accomplish with different goals. However it presents a drawback based on a high computation load due to non-linearity of problem definition. In this paper, it is presented a SHM implementation based on the Exchange Market Algorithm. This implementation aims to reduce execution time, heading to future online implementations, avoiding the use of offline calculations and look-up-tables, gaining the ability of adapt on real time the point of operation. Simulation results show the feasibility of the algorithm for solving the problem on a reasonable time for the online implementation in modern microprocessor demonstrators.

The search of efficient, robust and fault-tolerant electronic power converters is a challenge for the industry and academia. Nowadays, the integration and exploitation of the renewable energy sources and energy storage systems is required. In these terms, the multilevel power converters and specifically the cascaded H-bridge (CHB) power converter is a very good candidate. However, if a CHB power converter operates under an unbalanced operation a low-frequency high-distortion content appears in the output voltage spectrum. In order to reduce this problem, an extra cell, equipped with a low voltage battery or supercapacitor, is added to the original CHB converter. The idea is to operate the extra cell with the convenient duty cycle value in order to eliminate the low-order harmonic distortion generated by the unbalanced operation. This makes the proposed method very interesting because it leads to a reduction of the grid connection filter.

Multilevel power converters are very attractive for medium- and high-voltage applications because they present some advantages compared with the traditional two-level converters. In this way, the multilevel technology is backed by the industry and academia support. Among multilevel converters, the modular multilevel converter (MMC) is very popular because it is well-suited for the high-voltage dc (HVDC) power transmission systems as well as it permits the connection of different nature ac grids. To operate the MMC power converter is required a proper modulation strategy. It can be based on carrier-less or pulse-width modulation (PWM) strategies. In order to determine the optimum modulation technique, several simulations have been performed in order to extract some conclusions related with the power losses and the power converter behavior.

The use of interleaved power converters is a mature solution for multiple applications where the power is shared between several power converters. The interleaving method is used in order to improve the quality of the total output current. However, the performance of the complete power system is poor if an unbalanced operation is present in each power converter. In this paper, a variable-angle interleaving method is presented where the angle to be applied to carry out the interleaving is not fixed, but it is variable and calculated in real time depending on the operational conditions of the overall system. Simulation results are presented in order to demonstrate the good performance of the proposal.

Among multilevel converters, the cascaded H-bridge topology is one of the most industrially accepted solution for multiple applications, mostly for motor drives and flexible AC transmissions systems. Besides, other applications are being considered taking advantage of its modularity. The conventional phase-shifted PWM is the common method to generate the power devices switching of the converter. However, the performance is poor when an unbalanced operation is present. In this paper, an adaptive modulation method is presented where the angle to be applied to the phase-shifted PWM modulator is not fixed, but it is variable and calculated in real time depending on the operational conditions. Some simulation results are presented in order to demonstrate the good performance of the system.

The integration of renewable energy systems and specifically of solar photovoltaic (PV) systems into the grid has become an important issue in the last decade because of the huge expansion of new power plants. PV systems have experienced an important evolution in the overall efficiency and in the variety of locations from low power installations (PV roof systems in domestic and residential applications) to high-power power plants currently reaching up to 550 MW. This fact has led to the appearance of new PV converter topologies and, among them, multilevel converters are very attractive due to its good features such as high nominal power and high quality of output waveforms. In this paper, a multilevel cascaded H-bridge converter is used to directly integrate the PV arrays into the grid. The proposed controller implements independent MPPT algorithms for each H-bridge extracting all the possible power from the available irradiation. Simulation results are presented to demonstrate the good performance of the PV system. The proposed system is modular and can be easily scaled to reach higher power so it could be used in large PV plants just adding extra H-bridges to the converter.