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In the age of information, new platforms are consulted by patients to acquire consciousness about medical treatments. The aim of this study was to assess the level of understanding and feasibility of video consensus (VC) administration in patients scheduled for radical prostatectomy (RP), comparing it with standard informed consensus (SIC). According to the European Association of Urology Patient Information, we set up a video content for RP that was translated in Italian and implemented with information about possible perioperative and postoperative complications, days of hospitalization etc. From 2021 to 2022, all patients undergoing RP at our institution were prospectively included in this study. Patients received an SIC and after that, a VC about RP. After two consensuses were administered, patients received a preformed Likert 10 scale and STAI questionnaires. On the RP dataset, 276 patients were selected and 552 questionnaires for both SIC and VC were evaluated. Out of these, the median age was 62 years (IQR 60–65). Patients reported a higher overall satisfaction for VC (8.8/10) compared to the traditional informed consent (6.9/10). Therefore, VC may play a role in the future of surgery, improving the consciousness and satisfaction of patients and reducing preoperative anxiety.

Temperature monitoring is a major issue in induction motor drives, because temperature variations under working conditions may affect the machine lifetime and the control performance as well. The paper presents a technique for on-line monitoring the rotor and stator temperature on field-oriented induction motor drives, based on a new approach to estimate the rotor and stator winding resistances. The proposed approach exploits the injection of small additional current signals to extract the thermal status of the electrical machine, without affecting the normal drive operation. Moreover, it features a low computational effort, does not require other transducers than these already present in a standard field-oriented controlled drive and can be applied on both conventional and sensorless induction motor drives. The stator and rotor temperature estimation can be used either to prevent dangerous overheating and for on-line tuning of the control system. The practical effectiveness of the proposed approach is demonstrated by simulations and experimental tests.

Environmental climate change has encouraged countries across the world to develop policies aimed to the reduction in energy consumption and greenhouse gas emissions. The introduction of Zero-Emission Vehicles based on electrical powertrains, could reduce the emission of environmental pollutants, the noise levels and could increase the liveability of urban areas. Although in recent years research on batteries has brought several benefits to electric vehicle performance, key barriers to their adoption are still high cost, reduced autonomy, long charging times and the leak of a suitable network of charging stations. Substantial improvements in electric vehicles performance are expected with the development of new Li-ion batteries, thanks to some notable advantages over other types of batteries, such as: high energy density, high power density, long cycle life and long calendar life. This paper is aimed to present a reliability assessment procedure based on an ageing model able to estimate from datasheet information the lifetime of Lithium-ion batteries for electric vehicles, the residual capacity and reliability margins under different driving cycles, taking also into account the battery calendar ageing.

Prostate cancer (PCa) surgery has a strong impact on men’s social and sexual lives. For this reason, many patients ask for robotic surgery. To assess the rate of lost patients due to the lack of a robotic platform (RPl) at our center, we retrospectively selected 577 patients who underwent prostate biopsy between 2020 and 2021 who were eligible for radical prostatectomy (RP) (ISUP ≥ 2; age ≤ 70 yr). Patients eligible for surgery who decided to be operated received a phone call interview asking the reason for their choice. Overall, 230 patients (31.7%) underwent laparoscopic-assisted radical prostatectomy (LaRP) at our center, while 494 patients (68.3%) were not treated in our hospital. Finally, 347 patients were included: 87 patients (25.1%) underwent radiotherapy; 59 patients (17%) were already under another urologist’s care; 113 patients (32.5%) underwent robotic surgery elsewhere; and 88 patients (25.4%) followed the suggestion of friends or relatives based on their surgical experience. Despite no surgical technique for RP having shown superiority in terms of oncological or functional outcomes, patients eligible for PCa treatment decided to be operated on elsewhere because of the lack of an RPl. Our results show how the presence of an RPl may increase the case volume of RP by 49% at our center.

The paper presents a self-sensing control technique for a special type of multilevel motor drive featuring an Open-end Winding Permanent-Magnet Synchronous Motor fed on one side by a main multilevel inverter (MLI) and on the other side by an auxiliary two-level inverter (TLI). In order to minimize the power losses, the MLI manages the machine active power operating at a low-switching frequency. The TLI instead acts as an active power filter and operates at a higher switching frequency and a lower DC-Bus voltage than the MLI. The current control task is shared between the two inverters, as a predictive action is exerted by the MLI, while a feedback action is accomplished by the TLI. Common sensorless rotor position estimation techniques cannot be straightforwardly applied on such a system, due to the particular drive structure. Therefore, a specific technique has been carried out, able to ensure satisfactory efficiency and control performance in all the operating speed ranges by optimally exploiting the different features of the two inverters. Simulation and experimental results confirm the effectiveness of the proposed approach.

A new approach to obtain an integrated battery charger is described in this paper, based on the Asymmetrical Hybrid Multilevel Converter topology. Such a particular open-end winding motor configuration, which has proved to be more efficient than conventional inverter topologies in EV motor drive applications, can be turned in an on-board battery charger only by acting on the control system. Thus, no circuit reconfiguration through electro-mechanical switches is required. Moreover, by introducing a single extra power switch, a bilateral power flow can be managed enabling vehicle to grid operations. The obtained integrated battery charger can be supplied either by a standard ac single-phase grid, either by a dc power source for direct connection to domestic energy resources. The proposed approach enables a new remarkable function to the asymmetrical hybrid multilevel converter at a marginal extra cost, thus mitigating the larger complexity and cost of such an inverter if compared with conventional topologies.

A new approach to compensate rotor position errors caused by parameter mismatching in model-based sensorless synchronous reluctance motor drives is presented in this paper. According to the proposed approach, the error in estimating the rotor position is detected by injecting some low-frequency current signals and adjusting the estimated rotor angular position through a gradient descent algorithm until minimizing the ripple generated on the estimated rotational speed. A rotor position correction can be fully on-line accomplished coping with saturation and cross saturation effects, as well as with unmodeled phenomena and unpredictable variations of the stator resistance with the temperature. The correction procedure can be accelerated by starting from an approximated correction table, which can be off-line built using the same technique. The proposed approach does not need additional current or voltage sensors, nor motor design modifications, thus providing an inexpensive mean to improve the control performance and robustness. Although originally conceived to deal with back-EMF based sensorless control techniques, the correction procedure can be extended to other model-based sensorless SynchRel motor drives.

Multiple-motor fed by multiple-converter systems feature a set of electric motor drives sharing the load through a common mechanical coupling. Such a coupling is exploited in this paper to build up a sensorless field oriented control, based on a quite common back-EMF technique to estimate the rotor flux angular position and an original approach to correct estimation errors. The technique is based on the injection of a suitable, very low frequency, sinusoidal signal on the current reference of one of the motor drives. If the estimated rotor flux position is correct, the drive output torque does not show variations. Differently, a torque ripple is generated at the frequency of the injected signal, whose effects on the system speed are easily compensated by the main speed controller. However, due to the mechanical coupling, an additional component of the reference torque current at the frequency of the injected signal is generated on all the other drives. By minimizing such a component, the estimated rotor flux position can be corrected online. The proposed method can also be exploited to estimate actual values of the stator resistance and of the rotor time constant.

A technique to improve the performance of grid-connected induction motors by exploiting an auxiliary winding set is proposed in this paper. This auxiliary winding features the same distribution of the main winding, although with a reduced number of turns and it is fed by an inverter a fraction of the power in comparison with the rated size of the induction motor. As shown in the paper, through the auxiliary winding, it is possible to set the machine power factor, increasing the efficiency of the power conversion system and mitigating speed oscillations due to torque disturbances. A mitigation of the grid current peaks due to motor start-up is obtainable. First, the proposed technique is theoretically introduced, then a feasibility assessment is accomplished by simulations.

An optimal design strategy for Open Winding Asymmetrical Three-Level Inverters is proposed in this paper, to improve the performance in a large set of applications. The Asymmetrical Multilevel Inverter is composed of an open-end winding AC machine connected on one side to a main three-level inverter and, on the other side, to an auxiliary two-level inverter. The main inverter efficiently controls the active power flow operating at a low switching frequency, exploiting a selective harmonic elimination technique, while the auxiliary inverter acts as an active power filter, driven by a conventional high frequency PWM technique. A key point to maximize the efficiency of the entire system is to properly share the task of eliminating the undesired low-frequency voltage harmonics between the two inverters. An optimal strategy is proposed in this paper according to specific figures of merit, which are function of the DC bus voltage and switching frequency of the two inverters.

Piezoelectric energy harvesters (PEHs) are a reduced, but fundamental, source of power for embedded, remote, and no-grid connected electrical systems. Some key limits, such as low power density, poor conversion efficiency, high internal impedance, and AC output, can be partially overcome by matching their internal electrical impedance to that of the applied resistance load. However, the applied resistance load can vary significantly in time, since it depends on the vibration frequency and the working temperature. Hence, a real-time tracking of the applied impedance load should be done to always harvest the maximum energy from the PEH. This paper faces the above problem by presenting an active control able to track and follow in time the optimal working point of a PEH. It exploits a non-conventional AC–DC converter, which integrates a single-stage DC–DC Zeta converter and a full-bridge active rectifier, controlled by a dedicated algorithm based on pulse-width modulation (PWM) with maximum power point tracking (MPPT). A prototype of the proposed converter, based on discrete components, was created and experimentally tested by applying a sudden variation of the resistance load, aimed to emulate a change in the excitation frequency from 30 to 70 Hz and a change in the operating temperature from 25 to 50 °C. Results showed the effectiveness of the proposed approach, which allowed to match the optimal load after 0.38 s for a ΔR of 47 kΩ and after 0.15 s for a ΔR of 18 kΩ.

An open winding approach can lead to substantial performance improvement on grid-connected induction motors, which are still largely used for constant speed applications. Exploiting an open-end winding configuration to manage bidirectional power flows, the proposed configuration is less expensive than a conventional variable frequency induction motor drive, since a bidirectional controlled rectifier is not required, neither grid-side filters. In constant speed applications the proposed approach not only is able to maximize the average motor efficiency, but also to improve the power factor, limiting the start-up current and compensating the effects of voltage sags. Moreover, an energy storage system can be straightforwardly introduced in the system, enabling load peak shaving and load shifting operations. The proposed approach is first theoretical introduced and analyzed, then a performance assessment is accomplished by simulations.

Temperature monitoring is a major issue in induction motor drives, because temperature variations with the working conditions may affect the machine lifetime and the control performance as well. The paper presents a technique for on-line monitoring the rotor and stator temperature on field oriented induction motor drives, based on a new approach to estimate the rotor time constant and stator winding resistance. The proposed approach exploits the injection of small additional current signals to extract the thermal status of the electrical machine, without affecting the normal drive operation. Moreover, it does not require other transducers than those normally already present in a standard field oriented controlled drive and can be applied on both conventional and sensorless induction motor drives. The stator and rotor temperature estimation can be used either to prevent dangerous overheating, either to on-line tuning the control system. The practical effectiveness of the proposed approach is demonstrated by simulations.

The development of Lithium-ion batteries for electric vehicles have recently become the subject of large research efforts due to some remarkable advantages over other kinds of batteries, such as: high energy density, high power density, long cycle life and long calendar life. This paper is aimed to develop an ageing model suitable to estimate the battery lifetime, the residual capacity and reliability margins under different driving cycles, taking also into account the battery calendar ageing.

This paper deals with a novel hybrid transformer configuration able to face power quality issues occurring on modern distribution grids integrating distributed generation from renewable energy sources and non-linear power electronic loads. The proposed system encompasses a three-phase distribution transformer with secondary windings arranged according to an open-end configuration and a three-phase inverter with floating DC bus. Unlike previous hybrid transformers the proposed one does not require a bidirectional converter to manage bidirectional power flows, neither a tertiary winding to supply the inverter, thus allowing the use of standard MV-LV distribution transformers with simple modifications. The obtained power conversion system can be exploited to perform a voltage control at the distribution grid edge, a reactive power management and harmonic pollution mitigation. Simulations confirm the effectiveness of the proposed solution, ensuring high power quality voltage control under unbalanced grid and load conditions.

The main aim of this work is to provide a straightforward tool to modelize the thermal behavior of power module packages. The proposed circuit-based modeling approach takes into consideration the mutual thermal interaction among the dies, which plays a key role in the estimation of their working temperature. Furthermore, this modeling method features a compact and modular structure that can be easily tailored for different package configurations, maintaining limited complexity and computational burden. Last but not least, this thermal model includes both heating and cooling effects, thus allowing to evaluate thermal stresses even under pulse width modulated power devices. The thermal model is obtained starting from the temperature profiles carried out through a finite element analysis (FEA), by applying a power loss step to each single die. Starting from these profiles, a fitting curve algorithm is used to identify the elements of the RC networks used to represent the auto and mutual thermal impedances. The thermal model is thus an algebraic linear system including the RC networks parameters, and it can be exploited to identify the thermal status of each die of the power module even operating at different load conditions. The method has been applied in a SiC 3 phase inverter power module in which the high side and low side switches are formed with four parallel connected 1200V 350A SiC MOSFET dies. The results outgoing from the proposed model are confirmed by that carried out from FEA.

The growing number of Electric Vehicles in circulation, will soon pose the problem of how to manage spent batteries which, having exceeded their useful lifetime, no longer meet the specifications for usage in EV. A viable possibility is their reuse in applications less demanding than EV. This work is aimed to develop an ageing model able to predict the residual lifespan of EV Li-ion batteries in second life applications dealing with stationary energy storage systems.

An optimal current control strategy for asymmetrical hybrid multilevel inverters (MLIs) is proposed in this paper enabling their use on motor drives, static synchronous compensators, and photovoltaic and wind generators, where a fast and precise current regulation is required. A key feature of these highly efficient converters is that an ac machine (motor or transformer) operates according to an open-end winding configuration, connected on one side to a main MLI and, on the other side, to an auxiliary two-level inverter (TLI). The first efficiently controls the main power stream operating at a low switching frequency, while the TLI acts as an active power filter, exploiting a conventional high-frequency two-level pulsewidth modulation (PWM) technique. The proposed control scheme optimally exploits the key features of the two inverters by suitably sharing the control task. In fact, a predictive current control is assigned to the MLI, which can be accomplished by low switching frequency operations, while the high switching frequency of the PWM-operated TLI is exploited to accomplish a fast and precise closed-loop current control, processing only a part of the power stream flowing through the system, thus producing low power losses. Simulations and experimental results confirm the consistency of the proposed approach.

An open-end winding machine configuration and a suitable control strategy for medium-voltage ac motor drives applications are proposed in this paper in order to reduce the distortion of phase voltages in multilevel inverters (MLIs). Differently than standard open-end winding configurations, where two inverters provide active power to both sides of the stator winding, a main MLI supplies in this case the machine on one side, while an auxiliary two-level inverter acts as active power filter on the other side. A high efficiency step modulation manages the MLI, while the auxiliary unit is pulse width modulation (PWM) operated. As the phase current harmonic content is improved, the torque ripple is reduced and the drive efficiency is increased. By exploiting the proposed approach, the apparent switching frequency of the system is that typical of a PWM inverter, although the main unit is operated according to a voltage step modulation strategy. Simulation and experimental results confirm the consistency of the proposed methodology.

The paper deals with a technique to build sense coils on permanent magnet synchronous motors with minimum machine design modifications. Specifically, sense coils are realized by properly shaping the wiring of the thermistors placed in the end turns of the stator windings. Obtained sense coils can be effectively exploited on sensorless motor drives to mitigate the effects of parameters variation and system nonlinearities. A straightforward way to exploit the proposed technique to sensorless control surface mounted permanent magnet synchronous motor drives is also proposed and its effectiveness is assessed by experimental tests.

A novel three-phase multilevel inverter topology for open-end winding motor drives is proposed, featuring a reduced number of power devices. According to such a topology, only two of the motor phase windings are fed by a single-phase neutral point clamped inverter from one side, and a single-phase full bridge inverter from the other, the third motor phase being connected between the midpoints of the two inverters. The proposed topology can generate six different voltage levels in each motor phase and compared to a conventional three-phase three-level neutral point clamped inverter features a reduced amount of power devices and a higher efficiency. Simulations dealing with steady-state and transient conditions have been performed on a 1kW permanent magnet synchronous motor drive to demonstrate the effectiveness of the proposed configuration in a wide operating range.

A new approach is proposed to enable the self-commissioning on back-EMF based sensorless synchronous reluctance motor drives, providing an inexpensive mean to improve the performance and control robustness. The proposed approach is based on the injection of suitable current signals and on adjusting the estimated value of the rotor angular position in order minimize the ripple generated on a signal produced by a phase locked loop speed estimator. Exploiting such a technique look-up tables can be off-line built which can be used to on-line correct the estimated rotor angular position according to actual d,q stator currents. The proposed approach does not need additional current or voltage sensors, nor motor design modifications and can be also exploited to compensate the effects of the variation of the stator resistance with the temperature.

A novel approach of exploiting the stator-temperature-monitoring system to perform sensorless rotor-position estimation is described in this paper. The rotor position is, in fact, estimated by processing the voltages induced in thermistor cablings, which are modified in order to work as search coils (SCs). Using SCs, some typical drawbacks of sensorless position-estimation techniques based on the manipulation of fundamental components of stator voltages and currents, such as those related to inverter non-linearities, stator-resistance voltage drops, magnetic saturation and cross-coupling, can be overcome or mitigated. According to the proposed approach, a rotor-position-tracking technique for synchronous reluctance motor drives is developed independently from motor parameters. Such a sensorless rotor-position-estimation technique can be directly used to build up a sensorless controller or to improve the performance of conventional model based sensorless control systems. Simulations and experimental tests confirm the effectiveness of the proposed approach.

The development and the validation of an averaged-value mathematical model of an asymmetrical hybrid multi-level rectifier is presented in this work. Such a rectifier is composed of a three-level T-type unidirectional rectifier and of a two-level inverter connected to an open-end winding electrical machine. The T-type rectifier, which supplies the load, operates at quite a low switching frequency in order to minimize inverter power losses. The two-level inverter is instead driven by a standard sinusoidal pulse width modulation (SPWM) technique to suitably shape the input current. The two-level inverter also plays a key role in actively balancing the voltage across the DC bus capacitors of the T-type rectifier, making unnecessary additional circuits. Such an asymmetrical structure achieves a higher efficiency compared to conventional PWM multilevel rectifiers, even considering extra power losses due to the auxiliary inverter. In spite of its advantageous features, the asymmetrical hybrid multi-level rectifier topology is a quite complex system, which requires suitable mathematical tools for control and optimization purposes. This paper intends to be a step in this direction by deriving an averaged-value mathematical model of the whole system, which is validated through comparison with other modeling approaches and experimental results. The paper is mainly focused on applications in the field of electrical power generation, however, the converter structure can be also exploited in a variety of grid-connected applications by replacing the generator with a transformer featuring an open-end secondary winding arrangement.