With the requirements for reducing emissions and improving fuel economy, automotive companies are developing electric, hybrid electric, and plug-in hybrid electric vehicles. Power electronics is an enabling technology for the development of these environmentally friendlier vehicles and implementing the advanced electrical architectures to meet the demands for increased electric loads. In this paper, a brief review of the current trends and future vehicle strategies and the function of power electronic subsystems are described. The requirements of power electronic components and electric motor drives for the successful development of these vehicles are also presented.

Power Electronics and Motor Drives in Electric, Hybrid Electric, and Plug-In Hybrid Electric Vehicles

This paper presents a review of recently used direct torque and flux control (DTC) techniques for voltage inverter-fed induction and permanent-magnet synchronous motors. A variety of techniques, different in concept, are described as follows: switching-table-based hysteresis DTC, direct self control, constant-switching-frequency DTC with space-vector modulation (DTC-SVM). Also, trends in the DTC-SVM techniques based on neuro-fuzzy logic controllers are presented. Some oscillograms that illustrate properties of the presented techniques are shown.

Direct torque control of PWM inverter-fed AC motors - a survey

Field-oriented control and direct torque control are becoming the industrial standards for induction motors torque control. This paper is aimed at giving a contribution for a detailed comparison between the two control techniques, emphasizing advantages and disadvantages. The performance of the two control schemes is evaluated in terms of torque and current ripple, and transient response to step variations of the torque command. The analysis has been carried out on the basis of the results obtained by numerical simulations, where secondary effects introduced by hardware implementation are not present.

FOC and DTC: two viable schemes for induction motors torque control

This paper presents a new direct power control (DPC) strategy for a doubly fed induction generator (DFIG)-based wind energy generation system. The strategy is based on the direct control of stator active and reactive power by selecting appropriate voltage vectors on the rotor side. It is found that the initial rotor flux has no impact on the changes of the stator active and reactive power. The proposed method only utilizes the estimated stator flux so as to remove the difficulties associated with rotor flux estimation. The principles of this method are described in detail in this paper. The only machine parameter required by the proposed DPC method is the stator resistance whose impact on the system performance is found to be negligible. Simulation results on a 2 MW DFIG system are provided to demonstrate the effectiveness and robustness of the proposed control strategy during variations of active and reactive power, rotor speed, machine parameters, and converter dc link voltage

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Direct active and reactive power control of DFIG for wind energy generation

Medium-voltage (MV) induction motors are widely used in the industry and are essential to industrial processes. The breakdown of these MV motors not only leads to high repair expenses but also causes extraordinary financial losses due to unexpected downtime. To provide reliable condition monitoring and protection for MV motors, this paper presents a comprehensive survey of the existing condition monitoring and protection methods in the following five areas: thermal protection and temperature estimation, stator insulation monitoring and fault detection, bearing fault detection, broken rotor bar/end-ring detection, and air gap eccentricity detection. For each category, the related features of MV motors are discussed; the effectiveness of the existing methods are discussed in terms of their robustness, accuracy, and implementation complexity. Recommendations for the future research in these areas are also presented.

A Survey of Condition Monitoring and Protection Methods for Medium-Voltage Induction Motors

Urban population in the world accounts for 54%, with 69% in Italy, and it continues to grow (The United Nations Population Division's World Urbanization Prospects, 2015). In this work, energy sustainability has been analysed in urban contexts with high energy consumptions and low availability of renewable energy sources. The sustainable management of energy is a great opportunity in the complex environments of urban areas where the buildings are always an important contributor. Main results of recent research activities, carried out by the authors, are presented with energy-use models for buildings considering statistical bottom-up and top-down models. These models have been tested on about 50 municipalities in the Metropolitan City of Turin comparing the results of bottom-up models (at building scale) with the topdown model at municipal scale using a GIS tool. Finally, new hybrid models have been integrated to consider urban morphology, solar exposition and microclimatic variables of different urban environments. The use of a GIS tool consents to manage and represent buildings data at urban scale.

Hybrid models for the evaluation of energy sustainability in urban areas

In recent years a growing attention is being paid towards energy efficiency in civil and industrial applications. In order to achieve better efficiency and enhance the energy management strategies, better knowledge is needed on the characterization of energy consumers. Categorization of electrical consumers through clustering procedures has been widely addressed in the literature. However, the categorization of the thermal users has been considered to a lower extent, also because of the difficulty of gathering a sufficient and reliable amount of data. This paper analyzes the behavior of several final users on the thermal side. At first, the energy behavior of the buildings from a thermal point is defined by its energy signature, represented as a straight line derived from measurements gathered in the heating period. Then, the parameters of the energy signature are used within a clustering procedure to create consistent groups of buildings. The results enable the operators to identify salient features of the groups of buildings under analysis, and to monitor the changes carried out in the buildings, leading to possible changes of the group during time.

Clustering-based performance assessment of thermal energy management in buildings

This paper presents a simple power loss estimation method for inverter-fed low power AC asynchronous and synchronous motors. The method uses a simulation based DC/AC converter power loss estimation based on datasheet parameters and load characteristics like measured phase resistance and current phase delay. A current control scheme is used to impose a constant current at various speeds. Using this approach both asynchronous and synchronous motors can be used as a load. Total power loss is measured as the DC Link current by an amperemeter avoiding the use of complicated measurement systems.

A simple method for power loss estimation in PWM inverter-fed motors

Averaged Field Oriented Control

Nell'articolo vengono descritti e confrontati diversi sistemi di accumulo dell'energia elettrica per applicazioni stazionarie. Essi sono in grado di fornire molteplici servizi di rete con lo scopo di garantire i livelli di adeguatezza, sicurezza e affidabilita antecedenti l'elevata penetrazione della generazione distribuita

Michele Pastorelli

Papers

Hybrid models for the evaluation of energy sustainability in urban areas

Clustering-based performance assessment of thermal energy management in buildings

A simple method for power loss estimation in PWM inverter-fed motors

Averaged Field Oriented Control

Sistemi di accumulo: tipologie e applicazioni