Francesco Benzi

Electricity Smart Meters Interfacing the Households

The recent worldwide measures for energy savings call for a larger awareness of the household energy consumption, given the relevant contribution of domestic load to the national energy balance. On the other hand, electricity smart meters together with gas, heat, and water meters can be interconnected in a large network offering a potential value to implement energy savings and other energy-related services, as long as an efficient interface with the final user is implemented. Unfortunately, so far, the interface of such devices is mostly designed and addressed at the utilities supervising the system, giving them relevant advantages, while the communication with the household is often underestimated. This paper addresses this topic by proposing the definition of a local interface for smart meters, by looking at the actual European Union and international regulations, at the technological solutions available on the market, and at those implemented in different countries, and, finally, by proposing specific architectures for a proper consumer-oriented implementation of a smart meter network.

Communication protocols for electrical drives

The paper presents a review of the main communication protocols relating to industrial applications of electrical drives. In the factory automation context, drives are increasingly considered as intelligent actuators which require to exchange amount of data both mutually and with a supervising unit in order to improve the process quality. The protocols here considered are relevant either because of their diffusion in specific market areas (Profibus, FIP), or due to their specific design tailored to the drives (CAN bus, SERCOS). After a classification of the different networks, according to serial point-to-point or multipoint connection, the single protocols are reviewed in detail, by considering the most significant features from the point of view of the drive producer and user and showing how they can affect the control performances of the drives. In conclusion a comprehensive comparison table is reported for quick reference.

Communication architectures for electrical drives

The paper gives an overview of the communication architectures adopted in the industrial automation for the electrical drives, ensuring a fast data exchange and high performance control. An attempt is made at defining real-time operation for this application field, at reviewing the standardization work done to unify the electrical drive interfaces, and at encompassing the recently accepted solutions, including those based on the industrial Ethernet.

Powerline communication in electric vehicles

In full electric (EV) or hybrid electric (HEV) vehicles the onboard communication is a crucial issue, that can take advantage from a reliable and robust interaction among the embedded units (ECUs) providing among others the power and batteries management, services, accessories and supervision; an updated global view of the system under control (the car) can improve the quality of control, reliability, safety and comfort. Power Line Communication technology (PLC), that take advantage of the DC power line as a physical medium to exchange messages, according to standard protocols, is a candidate at substituting the actual wired solutions, by substantially reducing the cabling burden. The present paper aims at i) reviewing PLC technology for DC bus in the automotive sector; ii) defining the requirements of a reliable communication systems within a car environment, with special attention given to the data exchange needed by the more critical systems in EV and HEV, and namely the control of electrical actuators for traction; iii) describing a benchmark for testing the data transfer characteristics and performance, including details on proposed protocols and architectures and presenting experimental results on data channel characterization and transmission.

A field orientation scheme for current-fed induction motor drives based on the torque angle closed-loop control

A field orientation scheme for current-fed induction motor drives that is based on the closed-loop control of the torque angle is presented. Merits of the scheme are insensitivity to the rotor resistance and simplicity of implementation. The limits of the conventional field orientation solutions are reviewed. The scheme is then formulated, and its application to the induction motor drives fed by both current source inverters (CSIs) and current-controlled pulse width modulation (PWM) inverters is illustrated. As an example, the design of a CSI induction motor drive built up around the proposed scheme is detailed. The performance of the drive, obtained by simulation, is also given.<<ETX>>

Towards the powerline alternative in automotive applications

The power line technology has received an increasing attention in the last decades due to its inherent benefits, mainly related to the reduction of cabling and associated costs. Power line communication (PLC) was first employed in power utilities and since the 80s in home automation, too. However, its use in the automotive field received relatively little attention. This paper revisits the related work in using PLC technology for communication within the automotive domain and outlines its possible benefits. Then, it focuses on the issues that need to be addressed when introducing the PLC in the automotive domain. The final goal of this work is to carry out a practical assessment of the PLC technology in the referred domain that may open the way for future use in industrial scale.

Hybrid position/force sliding mode control of a class of robotic manipulators

This paper deals with the hybrid position/force control of a class of robotic manipulators. To perform the control scheme design, it is necessary to characterize the dynamical model of the force sensor which is mounted at the end-effector of the robot. The objective is to perform reliable contact force measurements by estimating all the forces which are generated at the level of the tip which is directly connected to the sensor. A dynamical model of the sensor motion is formulated and identified, by considering also the kinematics of the robot. The proposed hybrid control scheme includes position and force controllers based on first and second order sliding modes. These kind of controllers guarantee suitable robustness properties to perform a satisfactory trajectory tracking, also allowing one to make the robot move in an environment with unknown obstacles by using the possibility of touching the obstacles as a way to pass them by. Experimental tests are performed on a COMAU SMART3-S2 anthropomorphic rigid robot manipulator with an ATI Gamma force sensor by comparing four different position/force control schemes.

Characterization of the Dynamical Model of a Force Sensor for Robot Manipulators

Recent advances in robotics include the capability of planning a suitable trajectory in order to drive the robot from an initial configuration to a predetermined goal point, or to follow, when possible, a prespecified trajectory even in unknown environments [8]. Various methods can be adopted to accomplish this task. These methods are mainly classified in relation to the capability of the sensors which are employed to map the environment and the obstacles near the robot. When distance sensors and cameras are considered, the trajectory can be planned without colliding with the obstacles (i.e. no force measurements are required), see [3, 12, 13].

Design of a digital adaptive controller for electrical drives in industrial applications

The adaptive control of an electrical drive intended for positioning applications is addressed. The regulator is based on a pole-placement technique and an online identification algorithm. The results of previous work by the authors are reviewed and a more accurate modeling is worked out by including a term accounting for the torque; to this aim a static feedforward element is designed and added to the control scheme. The limit on the motor current provided in actual systems is taken into account, and a desaturation strategy is proposed and tested. A further improvement of the performances is obtained by a dynamical change in the saturation limits. A number of simulations are presented to illustrate the performance of the system. >

Energy smart meters integration in favor of the end user

Digital meters (electricity, gas, water, heating and cooling energy) play a crucial role within the Smart Grid environment. The paper will address the issue of their employment in two ways: i) the different type of counters, each at different stages in their digital implementation, should be able to exploit their computing and communication capabilities to achieve a complete integration of measurements and information, in order to provide a comprehensive energy assessment and added value compared to individual devices, ii) their use and their deployment should be evaluated not only in relation to the possible advantages for distributors and utilities, but also with special attention to the end user and the community, given the key role of the final consumer in achieving energy efficiency. To this aim, the paper will present the latest technological developments of the meter types and will propose a design methodology (architecture and protocols) that makes their integration possible and profitable.