This paper presents a buck-boost DC-DC converter design featuring a wider voltage gain capability. The proposed topology offers advantages such as continuous input current and a common ground connection shared by the input and output ports. The proposed converter's low input current ripple makes it particularly suitable for renewable energy applications, such as photovoltaic (PV) systems. In contrast to conventional buck-boost converters, which typically invert the output voltage polarity, this design delivers a positive output voltage. Additionally, the converter employs only a single main switch, which also benefits from reduced voltage stress, enhancing both reliability and operational efficiency. The converter's operation is grounded in detailed mathematical modeling, with simulation and experimental validation confirming consistency between theoretical predictions and practical performance.

DC-DC converters play a crucial role in providing power conversion for the integration of renewable energy sources into the electric power grid or as standalone power sources. However, achieving proper integration of applications like photovoltaic generators often requires DC-DC converters with an enhanced voltage range due to conditions such as PV shadowing. This is a feature that is lacking in standard DC-DC converters. Addressing this need, this paper presents a novel transformerless buck-boost converter with a wide conversion voltage ratio. The proposed converter has only one active switch, simplifying the gate driver and control system implementation. The wide conversion voltage ratio is ensured by its quadratic voltage gain. Operates in both step-up and step-down modes, unlike most existing quadratic topologies, which are limited to either step-up or step-down operation, and shares a common ground between the input and output terminals. The operational modes of the proposed converter and its steady-state performance are thoroughly analyzed. Simulation and experimental tests were conducted to evaluate its performance.

DC-DC converters are widely used to provide power conversion in electrical/electronic appliances and portable electronic devices. Over the last few decades, they also have been played a key role in the integration of renewable energy sources into the electric power grid or as standalone power sources. However, to achieve proper integration of certain electric/electronic devices/drives or photovoltaic power in shadowing conditions, it is frequently imperative to employ DC-DC converters that possess enhanced voltage amplification, a capability that standard DC-DC converters lack. According to this need, this paper proposes a new DC-DC Buck-Boost converter using a single power semiconductor switch. The proposed topology provides wide conversion voltage ratio, reduced voltage stress in the power semiconductor and reduced ripple of the input current. The operation principle of the proposed converter and the static gain will be discussed through a theoretical analysis. The performance of this power converter will be tested through simulations and experiments.

This work presents a three-phase on-board integrated battery charger for electric vehicles with a three-phase machine with open windings. The vehicle motor is supplied by a modular multilevel inverter composed by three three-phase inverters. The input of the charger will operate as a three-phase power factor correction converter and present output Buck-Boost features. In the proposed solution, all windings of the motor are used as DC inductors of the battery charger in a way that will result in a torque cancellation. A detailed description and analysis of the proposed on-board integrated battery charger is presented in this paper. On the other hand, an associated fast and active current controller is also proposed to ensure the unit power factor of the rectifier. The feasibility, characteristics and validation of theoretical deductions will be confirmed through several simulation tests.

Due to the new paradigm in which AC grids must coexist with DC microgrids, new solutions to interlink those networks are required. In this context, a new interlink hybrid converter is presented in this paper. This solution is designed to interlink AC grids and bipolar DC microgrids or two DC microgrids. The simplest solution allows linking a three-phase AC grid using only two single-phase inverters. However, it can be extended with the purpose to make a multilevel converter. The solution allows to transfer the energy in a way that supports the attenuation of the voltage unbalance that can appear in the DC microgrid(s). This support is done by an independent transference of energy to the microgrid poles or microgrids. This concept and behavior of the interlink hybrid converter will be tested through simulation studies. The results obtained in these studies show the capability of the proposed solution.

Nowadays DC microgrids provide a valuable alternative to AC technology in the context of electrical energy distribution grids and increasing energy demand. One of the main structures of DC microgrids are the bipolar solutions. Although presenting several advantages over unipolar solutions, the major problem is the voltage imbalance that can appear. This paper presents a non-isolated bipolar DC-DC converter to be integrated in battery storage systems. The converter was designed to transfer energy between the DC microgrid and batteries, and at the same time, to support the balance of the bipolar DC microgrid. This support can be achieved in two ways, namely through the transference of the energy between the DC microgrid and batteries using only the pole that requires support for the balance or as a standalone voltage balancer. Simulations and experimental results of the DC-DC converter operating in bidirectional mode will be provided. From the presented results, it will be possible to verify the capability of the converter to operate as bidirectional interlink between the battery storage systems and the bipolar DC microgrid.

In this work it is proposed a switched reluctance machine (SRM) drive supplied by a renewable source (PV array) to operate a water pumping system. To improve the speed of the commutation between phases it is proposed the use of a multilevel converter for the SRM drive. This converter was designed to reduce the number of controlled power semiconductors, reducing the cost of the system. To obtain the maximum power extraction of the PV system is proposed the use of an algorithm based on the product of the time derivative of power with the time derivative of voltage. A control system to ensure the balance between the power generated by the renewable source and the water pumping system is also proposed. The operation and characteristics of the system will be verified by several numerical tests.