Different maximum power point tracking (MPPT) techniques used in photovoltaic (PV) systems are evaluated based on several criteria such as simplicity, speed, and accuracy. There are tradeoffs among these criteria, and generally higher accuracy is achieved at the expense of speed and simplicity. The aim of this paper is to introduce Spline-MPPT technique as a fast, accurate, and uncomplicated method to find the maximum power point of PV systems under uniform irradiance and partial shading condition (PSC) in which characteristics of the PV string are distorted. The proposed method is based on cubic spline interpolation that defines an approximate function for a few sample points. Several interpolation-based methods have been proposed in the literature to find MPP under uniform irradiance. They, however, are incapable of finding the global maximum power point (GMPP) under partial shading conditions. The Spline-MPPT technique only uses a small number of current and voltage samples to estimate the MPP of the system and maintain on this point as long as environmental conditions remain unchanged. Simulation results attest to the superiority of the proposed method.

The paper introduces a straightforward procedure for estimating the electrical parameters of a simple, but reasonably accurate, two-branches model of a supercapacitor (SC). The equivalent electrical circuit model includes the voltage and frequency dependence on the SC’s capacitance, neglecting the self-discharge phenomenon, so it is mainly devoted to short and mid-term simulations suitable for most industrial applications. The estimation procedure of the electrical parameters starts by analysing the experimental data achieved by a common constant-current discharge test. Such data are used to build a fitting function which is compared with the analytical solution and numerical approximations for the SC’s voltage evolution. Thus, initial estimated values of the electrical parameters are obtained through simple relations and are optimised by implementing the least squares method. The procedure is validated after an easy and fast extraction of the optimal parameters of the two-branches model of an SC. Several tests involving a commercial SC have been carried out in Simulink and the results have been compared against experimental data. A good accuracy of the two-branches model in a wide range of constant-current charging/discharging cycles is reported.

Space vector pulse width modulation (SVPWM) is a superior switching technique offering several benefits for power electronic inverters. However, concerning multilevel inverters (MLIs), implementing SVPWM is a demanding and time-consuming task because it deals with the six sectors of the space vector modulation (SVM) plane and numerous regions and vectors. Several research works in the literature tried to simplify SVPWM implementation for MLIs. This paper introduces an SVPWM strategy, aiming to simplify the designing process and reduce the computational burden of the multilevel SVPWM. In this method, the switching process is designed only for the first sector of the SVM plane. The duty cycles and the switching states of the other sectors are assigned by transferring and translating techniques. The proposed method only uses basic algebraic functions in order to save the limited hardware resources of the processor. The same basic functions are used to handle overmodulation (OM) operations. This method introduces the boundary lines concept, which is a useful tool to detect the region and assign the switching states. Simulation and hardware-in-the-loop (HIL) results are provided to validate the functionality of the proposed SVPWM. The hardware resource used on the FPGA module is adopted as a criterion to compare the proposed method with one of the conventional SVPWMs. This article is accompanied by MATLAB simulation files, for a 3-level and a 5-level inverter, provided by the Auhors as supplementary material.

The evolution of power generation brings about extensive changes in other parts of the grid, especially in the transmission and distribution components. Within the scope of the Internet of Energy (IoE), electric power flows more flexibly between different parts of the grid. DC power will play an essential role in IoE. Decentralized photovoltaic panels, energy storage, electric vehicle charging stations, and data centers are some of the significant components of future grids dealing with DC power. As a result, power transformers must be appropriately modified to manage power among the different parts of the grid. A power electronic transformer (PET), also known as a solid-state transformer (SST) or smart transformer (ST), is a solution enabling a power grid to deal with this growing complexity. ROMAtrix, as a matrix-converter-based ST, is a developing project targeting future power grids. ROMAtrix realizes the application of a medium voltage (MV) transformer using commercially available power electronic semiconductors. Due to the distinctive features of ROMAtrix and a high number of switches, the implementation of the control system using a single control board is highly demanding. This paper aims to illustrate the implementation, on a field-programmable gate array (FPGA), of pulse width modulation (SVMPWM) applied to the ROMAtrix, considering specific switching patterns. The proposed switching procedure was simulated with PLECS and validated with the hardware-in-the-loop using the OPAL-RT solver.

Despite numerous advantages of space vector pulse width modulation (SVPWM) methods, their implementation on multilevel inverters (MLI) is onerous. Due to the ever-increasing use of MLIs in power electronic applications, it is essential to implement efficient modulation procedures aiming to keep control sampling periods sufficiently short. This paper proposes a straightforward SVPWM Strategy, which uses algebraic functions throughout the procedure and avoids using hardware-consuming trigonometric functions. Look-up tables and region detection are no more necessary. It also generates switching states automatically, without requiring any data in advance. As another simplification, the proposed SVPWM is only designed for the first sector, instead of six sectors of the space vector modulation (SVM) plane. This simplification is done via transferring and translating techniques. Regardless of the number of voltage levels, the proposed SVPWM strategy is comprehensively applicable to any n -level three-phase inverters, without any major modification. Simulation and experimental results attest to the authenticity and effectiveness of the proposed SVPWM. As the supplementary materials of this research, MATLAB simulation files are provided together with the manuscript.