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.

The unsustainable use of resources (water, gas, and electricity) contributes to the intensification of global warming. On the other hand, the indiscriminate use of electrical resources poses serious problems to the sustainability and operability of the power grid. One of the solutions to mitigate this problem refers to responsible use of resources by the domestic user, creating new habits, without giving up their lifestyle and comfort. The creation of a game supported by a web application, which allows the use of group game techniques, can promote the increase of efficient consumption by the users. This work presents the development of a game which aimed at the consumption awareness of the participants. The competition between users was stimulated by the attribution of points, using the weekly consumption comparison of groups formed by the participants. Other functionalities, allowing users to obtain extra points, were designed to keep a high level of engagement.

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.

This paper presents the design and implementation of a grid-forming control for a dual-purpose dc-dc/ac PWM modular power converter tailored for three-phase three-wire ac conversion in nanogrid applications. The study emphasizes the integration of grid-forming and droop control mechanisms to ensure system stability and controlled power sharing. Extensive simulations and analyses demonstrate the effectiveness of the proposed control strategy, yielding swift and precise responses to dynamic power demand changes. The research offers valuable insights into the operation and functionality of this power converter topology within ac nanogrids, contributing to enhanced grid flexibility and reliability in renewable energy systems.

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.

As power systems move towards decentralized models based on renewable energy sources with distributed generation, the role of power inverters in microgrids becomes increasingly important. In this paper, a three-level T-type quasi-impedance source inverter (3L-T-type qZSI) with a grid-forming control structure is studied for the first time in an islanded ac microgrid composed by three prosumers, supplying residential loads. The power sharing among prosumers is achieved through the well-known droop control method with virtual impedance, and proportional-resonant (PR) controller-based voltage and current control loops. A proportional-integral (PI) based control for regulating the dc-link voltage of the T-Type inverter was implemented making use of the boost ability of the qZS network. The proper operation of the microgrid has been tested by simulation with PLECS, demonstrating a robust behavior of the overall system and a good dynamic performance of the proposed control structure for the 3L-T-Type qZSI in different conditions.

High-Voltage Direct-Current (HVDC) is an attractive solution to conventional ac transmission systems, to transmit bulk electric power over long distances. Multilevel bipolar back-to-back dual inverters convey advantages to HVDC systems, at the cost of increased difficulties to control the AC currents and DC link voltage. This paper presents a control approach for a bipolar HVDC transmission system based on a dual two-level inverter topology with a multilevel structure. For both multilevel inverter AC sides a model predictive control strategy is designed to control active and reactive power, establishing AC grid currents in the sending and receiving ends. The multilevel converter also guarantees the balancing of the DC bus capacitor voltages. To test the performance and effectiveness of this proposed control strategy, several simulation studies are presented and discussed.

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.

This paper presents fault tolerant topologies for the three-phase dual-buck voltage-source inverter (VSI). Using the proposed topologies, increased reliability is obtained, which is fundamental in many safety-critical applications. The solutions intend to achieve fast changing between main and redundant branches through the combination of several power devices. The present study focuses on solutions that can be used to replace the classical two-level three-phase voltage-source inverters to extend the fault-tolerant capacity. Several aspects of failure modes, detection and isolation processes within power electronic converters are discussed regarding the requirements of safety related applications. The theoretical validity of the proposed solution is confirmed by simulation results.

The quasi-Z-source (qZS) inverter has emerged as one interesting solution for several types of applications, like those associated with renewable energies. The qZS inverter presents a wide range voltage gain and does not require dead times improving the system reliability. One of the most interesting qZS inverter topologies is the T-Type multilevel converter. Nevertheless, the T-Type multilevel may have issues related with the capacitor voltages imbalance. Therefore, this work proposes the use of model predictive controllers (MPC) to mitigate the capacitor voltages imbalance issue. The optimization cost functional will weight three criteria, the capacitor voltage imbalance, the level of the voltage of the series connected capacitors and the AC currents errors. To test the proposed control strategy, several simulations studies are presented and discussed.

Reliability has become a mandatory feature in many safety critical applications, where major accidents, equipment damage or expensive downtimes must be prevented. One of the major qualities of the switched reluctance motor (SRM) is its high fault tolerance features. Although this motor can be able to continue operating even with some of its phases disabled, in this situation it appears an important torque ripple that could affect its proper functioning in some applications. This paper presents a novel low cost spilt-winding fault-tolerant approach, together with the correspondent power converter, that enables the motor to continue normal operation in the case of a winding open circuit. The obtained results show that the proposed solution, and its inherent fault tolerance behavior does not present a huge impact on the overall motor efficiency.

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.

This paper presents a quasi-Z-source (qZS) converter that allows to supply multilevel voltages for the switched reluctance machine (SRM) drive. The use of qZS converter in SRM drives allows obtaining better high speed operation characteristics since higher voltages can be achieved. The proposed drive uses a qZS converter but designed in order to be possible to apply, to the SRM, different voltage levels on the magnetizing and demagnetizing stages. The presented converter also allows to regulate the output voltages and the difference between the voltage levels. Thus, it is possible to improve the efficiency of the drive, by reducing the switching frequency, as well as having better characteristics for high-speed operation. Different configurations of the converter are presented and the modulator associated to the SRM drive is described. In order to verify the features of the proposed system several results are also presented and discussed.

This paper presents a four wire dual-buck inverter integrated in a photovoltaic system with grid support capabilities. In the context of smart-grids this kind of systems can play an important role. In this particular case the system will supply the ancillary services for unbalanced loads and reactive power compensation. A dual-buck inverter is adopted in order to ensure a higher reliability. This kind of inverter is characterized by the non-existence of shoot-through problems and by the possibility of the using power MOSFETs as active switches. The control system for the dual-buck inverter with the ancillary service functions is also presented. In order to verify the performance of this system several simulation results are presented and discussed.

The study and assessment of Power Quality issues is nowadays a very important subject, particularly regarding Cyber-physical and Industrial Agents based systems, which are extremely sensitive to Power Quality disturbances. Giving students or engineers practical experience in this field requires a large investment from teaching institutions. This paper presents a laboratory device that emulates Power Quality disturbances in order to provide the required experimental expertize in the subject. It addresses limiting aspects such as harmonic distortion, flicker, sags, swells and transients. The developed system presents a good opportunity for technicians, even without deep knowledge on the field of power quality, to learn basic principles and be able to identify Power Quality events. Since the system is based on real data, represents a valuable approach giving trainees practical knowledge on the field.

The perspective of Smart Grid developments brings a picture with active distribution networks having many distributed resources such as PV connected to the grid through inverters. The challenge for this future is so complex that the Smart Grid Coordination Group (SG-CG) is already considering for standardization in the new Use-Case cluster "Connect and active actor to the grid", the high level use case "Managing generation connection to the grid". This is considered as emerging necessary functionality of the "Distribution management system", to be subject of CEN/CENELEC standardization. This paper presents enabling solutions for these requests and proposes solutions for Automated Remote Grid Acceptance and Energy Services Tests using new concepts for the Smart Meter and for the inverters design. Results to sustain the proposals are also sustained by a case of simulation for a Grid Acceptance test - Fault Ride Through with reactive power and for an Energy Services Test proving interphase simetrization service.

In this paper a wireless home automation system is presented The proposed system allows controlling devices in a home environment by using a simple Bluetooth equipped mobile phone. The mobile phone communicates with a main Bluetooth/ZigBee module that communicates with the different ZigBee modules acting as the coordinator of the ZigBee network established between all nodes where electrical devices are connected The identification of each device is made through DomoML strings by using the KNX home automation standard protocol.

In this paper a low-power wind generation grid-connected system for domestic consumers with two control modes (Maximum Power Point Tracking (MPPT) and Power Control (PC)), will be presented. The MPPT mode will be active when the home's load is higher than the wind generator's maximum available power and the PC mode will be active when the home's load is lower than the wind generator's maximum available power. These two techniques will be adopted to both optimize the wind system performance and to prevent power injection into the electrical grid. Hence, the PC mode will be a particularly important part of this system. It will also be crucial to assure that the controller decides correctly on which control mode should be active, given the current grid supplying power.

One of the most used power converters is the three-phase voltage source power inverter. This is one of the reasons why it is so important to assure a continuous and safety operation of this power converter. This paper considers the application of the S-Transform to detect and identify faulty power switches in voltage source inverters. The S-Transform is applied to the inverter output currents in order to get a specific pattern that allows the identification of the fault. This results in a fast and reliable fault detection methodology. The applicability of the proposed technique is confirmed through simulation and experimental results.

One of the most used power converters is the three-phase voltage source power inverter. This is one of the reasons why it is so important to assure a continuous and safety operation of this power converter. This paper considers the application of PCA and average value computation to detect and identify faulty power switches in voltage source inverters. The PCA is applied to the inverter output currents in order to get a specific pattern that allows the identification of the fault. This results in a fast and reliable fault detection methodology. The applicability of the proposed technique is confirmed through simulation and experimental results.

In this paper it is presented an approach to improve the interpretability of a neuro-fuzzy system. This improvement is achieved through the modification of the Sugeno form of the consequent polynomials into corresponding triangular membership functions. The resulting neuro-fuzzy inference system has the same performance as the initial one and is an extension to our already published neuro-fuzzy architecture. This architecture has been used in the classification and control applications. In simulation, the proposed approach is applied after the corresponding neuro-fuzzy model of a non-linear function is obtained. A helicopter motion controller model was used as the non-linear function. The increase of interpretability of the controller shows the effectiveness of the proposed approach.