In this document a DC/DC converter for power conversion between +28V/+270V voltage levels is presented, and the main characteristics of the converter are discussed. The topological structure is first introduced, outlining the hardware components used and the modular approach. The step-down (or Buck) and step-up (or Boost) modulations are then discussed, focusing on the switching signals to drive the low-voltage and high-voltage bridges of the single modules. The description of the control phase follows, justifying the controller used to steer the output voltage towards the desired value. The firmware realized for the converter management is equipped also with a supervision and protection logic, realized as a composition of finite state machines. Finally, simulative results and real measurements are provided to evidence the correctness of the overall topological choices and of the control system realized for the bidirectional converter, focusing also on the comparison between the expected results and those obtained.

In this paper, the theoretical analysis and the experimental validation of a modified version of the maximum power point tracking technique, that is known with the acronym TEODI, are presented and discussed. The modified version of TEODI (MTEODI) outperforms TEODI in photovoltaic (PV) applications operating under mismatching conditions. The working principle of MTEODI is based on the periodic measurement of the short-circuit currents of the PV units. The knowledge of such currents allows not only the determination of whether mismatching conditions occur but identification of the values of the suitable correction factors, on which the working of MTEODI is based, as well.

The growing number of electric vehicles (EVs) affects the national electricity system in terms of power demand and load variation. Turning our attention to Italy, the number of vehicles on the road is 39 million; this represents a major challenge, as they will need to be recharged constantly when the transition to electric technology is complete. If we consider that the average power is 55 GW and the installed system can produce 120 GW of peak power, we can calculate that with only 5% of vehicles in recharging mode, the power demand increases to 126 GW, which is approximately 140% of installed power. The integration of renewable energy sources will help the grid, but this solution is less useful for handling large load variations that negatively affect the grid. In addition, some vehicles committed to public utility must have a reduced stop time and can be considered to have higher priority. The introduction of priorities implies that the power absorption limit cannot be easily introduced by limiting the number of charging vehicles, but rather by computing the power flow that respects constraints and integrates renewable and local storage power contributions. The problem formulated in this manner does not have a unique solution; in this study, the linear programming method is used to optimise renewable resources, local storage, and EVs to mitigate their effects on the grid. Simulations are performed to verify the proposed method.

On the base of the MMC principle, this work considers different topologies of sub module (or elementary converter) which make the High Voltage AC/DC converter more flexible and easy suitable respect to different voltage and current levels. A topological study is consolidated and extended on three different topologies proposed as elementary converter and their employment for the MMC structure is treated. For each cell, topology advantages and limits are discussed in terms of current and voltage. Under SPWM modulation conditions, an analytical approach for the power losses evaluation is proposed for the three topologies used in the MMC structure. A comparison on the efficiency is proposed by fixing the DC voltage and the operating power. By considering the basic topology of the MMC (composed by elementary cells) also an evaluation of the power losses is performed by considering the staircase modulation which is becoming more and more diffused especially for a high number of levels.