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PM brushless DC (BLDC) motors should be fed by square-wave currents synchronized with the back emfs to develop a constant torque with the required value. In practice, phase inductances and limited source voltage produce non ideal square-wave currents and unbalanced phase currents during commutations. Such phenomena affect the torque developed by the PM BLDC drives by deviating its value from the requested one and by giving rise to torque ripple. In this paper, an analytical study of the torque characteristics, namely motor torque and torque ripple, of PM BLDC drives is carried out as a function of the motor speed and is supported by experimental data. Torque characteristics are expressed in terms of a quantity distinctive of the motor, thus giving a generalized formulation to the results.

The paper presents a maximum power point tracking algorithm based on a neural network implementation and aimed to search the optimal working point in two different photovoltaic technologies coupled to a buck-boost DC-DC converter. The neural network generates the current reference for the control algorithm that manages the DC-DC converter switches. The paper analyzes the neural network training and reports the results obtained considering the two different PV technologies.

This paper presents a comprehensive development of a dynamic wireless power transfer (WPT) system for the charge of the battery onboard an electric vehicle (EV). The development starts from the assessment of the electrical specifications of the dynamic WPT system, goes through the design of its power stages, and concludes with its validation. In the design step, the structure of the coupling set, layout of the coils, configuration of the conversion stages and topology of the compensation networks are illustrated, as well as electrical sizing of the power stage components. In the validation step, the setup of a dynamic WPT system is described, and the results of experimental tests carried out with the pickup moving along the track are given.

The paper presents the activities ongoing in the framework of a two-year Italian National Research Project aimed at developing a distributed Driving and Steering (DaS) system for Electric Vehicles (EVs). The system is built up around an actuation module embedding a rotary-linear motor and including a power converter and a local Electronic Control Unit (ECU) to supply and control the motor. The actuation module is intended to make a wheel active so as to give it propelling and steering capabilities. The DaS system, in turn, includes a central ECU and a fieldbus to govern and network the system, and a power supply stage. The Project under consideration is focused on a DaS system with two active wheels for a light-duty EV.

The paper deals with a direct torque control (DTC) scheme for Induction Motor (IM) drives where flux and torque of the motor are estimated by the IM current model instead of by the voltage model. The scheme is intended to enable operation of the DTC IM drives at zero speed. As a return, its implementation requires the knowledge of speed, rotor time constant and inductive parameters of the motor. In the paper the performance of the proposed scheme is studied for a drive equipped with an incremental encoder and commanded with a constant flux. Using the position information delivered by the encoder, a suitable representation of the current model is formulated that makes the drive operation feasible at true zero speed. Operating with a constant flux command, the variations in the rotor time constant dominate over the other parameters; their effect on the drive behavior is analyzed in steady state founding that the motor flux and torque are deviated from the references of a quantity, which is a function of the torque reference. Experimental results are given to substantiate both the capabilities of the scheme of developing the full torque at a standstill and the theoretical findings on the drive behavior under rotor time constant mismatch.

Steer-by-wire (SbW) systems are candidate to substitute the conventional (mechanical or hydraulic) steering systems in the new generation of vehicles. The task of a SbW system is twofold: turning the road wheels tracking the handwheel rotation and providing the driver with a feeling of the steering effort. In this paper, the issue of designing a SbW system is faced. An approach is proposed, based on three steps. Firstly, the model of a conventional steering system is formulated. Then the SbW system is developed with the same structure as the conventional ones. Finally, performance indexes for the steering maneuver are defined and utilized to set up the parameters of the SbW system. As a case of study, the SbW system of a lift truck is designed according to the proposed approach. Diagrams are given to demonstrate the effectiveness of the resultant SbW system

A novel scheme for the direct torque control (DTC) of an induction motor (IM) is proposed, which uses a single sensor of current inserted in the inverter dc link. The rationale behind the proposal is to develop a low-cost but high performance IM drive. The scheme exploits a simple and robust algorithm to reconstruct the stator currents needed to estimate the motor flux and torque. The algorithm operates in two stages: first, it predicts the stator currents from a model of the motor and then adjusts the prediction on the basis of the sensed dc-link current. Experimental results are given to demonstrate the ability of the scheme in reproducing the performance of a traditional DTC IM drive.

Steer-by-wire (SbW) systems are candidate to replace the conventional steering equipment in the new generation of vehicles. The task of a SbW system is twofold: turning the steered wheels by tracking the handwheel rotation and providing the driver with a feeling of the steering effort. In this paper, the design of the control scheme for SbW systems is faced. Two schemes are considered: one is derived from the model of conventional steering equipment whilst the other one exploits the features of a SbW system to cope with the interaction of the steered wheels to the road surface. Implementation of the control schemes on a test vehicle is described and experimental results are given.

The introduction of drive-by-wire (DbW) systems in the vehicles makes it feasible the implementation of active controls to improve the driving safety. In this paper, an anti-roll control for a lift truck is developed by exploiting the capabilities offered by a DbW system. To this aim, a suitable multi-mass model of the lift truck is formulated and the rollover condition is analyzed for both pivoting and locked rear axle. From the analysis, the longitudinal speed at which rollover begins is found as a function of the cornering and loading situations. Further to this result, the anti-roll control is arranged that substantially operates by conditioning the speed command entered by the driver. Hints on the implementation of the control are dropped