Showing papers by "Giuseppe Buja published in 2009"
TL;DR: The fourth edition of the Formula EHI competition was held in the safety testing center of Fiat Group Automobiles in Orbassano (TO), Italy from 1 to 3 October 2008 as mentioned in this paper.
Abstract: From 1 to 3 October 2008 the Formula Electric and Hybrid Italy took place in the Safety Testing Center of Fiat Group Automobiles in Orbassano (TO), Italy. This fourth edition of Formula EHI, an international competitive demonstration of research outcomes from university student teams, has brought to the attention of the public and of the industry new technologies and innovative applications in the area of the systems addressing the ecological mobility. Teams from five European countries were the protagonists of the event. Several projects, components, systems and concept have been presented, related to advanced technologies for battery electric, hybrid and fuel cell vehicles. New technology hybrid, fuel cell and electric vehicles took part to the dynamic test on track for the evaluation of energy efficiency performance and dynamic behaviour. The 2008 event was a further step of the editions of Formula TECH held in the previous years and offered a benchmarking overview of the progress of the technology in the field of electrically propelled vehicles.
8 citations
01 Nov 2009
TL;DR: The characteristics of the ZSI supply for the two basic types of PM brushless motor, namely the dc and ac types, are assessed with regards to the switch solicitation and utilization and the traditional dc-dc boosted inverter supply is compared.
Abstract: Z-source inverters (ZSIs) supply ac loads from a dc source and boost the voltage of the dc source in a single stage. Such an ability is much needed in electric vehicles where the rated voltage of the traction motors is usually higher than the voltage generated by the onboard dc sources. Being the technological trend in the traction drives directed toward the employment of PM brushless motors, the use of a ZSI for their supply is a cuttingedge issue, which is investigated in this paper. The paper starts by formulating the equations of a ZSI in a suitable form. Then the characteristics of the ZSI supply for the two basic types of PM brushless motor, namely the dc and ac types, are assessed with regards to the switch solicitation and utilization. As a comparison, the characteristics of the traditional dc-dc boosted inverter supply are also given.
7 citations
TL;DR: In this paper, a novel strategy that forces the active compensator to deliver a particular value of the instantaneous imaginary power absorbed by the time-variant load is proposed, which is compared with the two conventional ones in terms of magnitude of the voltage fluctuations at the point of common coupling (PCC) and size of the capacitor in the dc bus.
Abstract: This letter is concerned with the strategy adopted by an active compensator to mitigate the flicker phenomenon in a power system. After illustrating two conventional strategies, a novel strategy that forces the compensator to deliver a particular value of the instantaneous imaginary power absorbed by the time-variant load is proposed. The strategy is compared with the two conventional ones in terms of magnitude of the voltage fluctuations at the point of common coupling (PCC) and size of the capacitor in the dc bus of the active compensator. Suitable equations and vector diagrams are derived. They show that the novel strategy outweighs the other two by eliminating most of the PCC voltage fluctuations without the need for a large capacitor. The theoretical findings are substantiated by simulation results.
3 citations
23 Oct 2009
TL;DR: In this paper, the operation of a brushless DC drive during phase commutation was investigated and the various switching patterns that can be used to command the inverter were identified, and it was demonstrated that the switching patterns are a combination of two basic commutation modes.
Abstract: The paper deals with the operation of a brushless DC drive during the phase commutation. At first, the various switching patterns that can be used to command the inverter are identified. It is demonstrated that the switching patterns are a combination of two basic commutation modes. For each mode, the current transients during the phase commutation are determined as well as two significant commutation-related quantities, namely the decay angle of the current in the outgoing phase and the maximum current excursion in the non-commutating phase. The results obtained for the two modes are then compared, showing that each switching pattern gives a brushless DC drive specific properties.
3 citations
01 Jul 2009
TL;DR: In this paper, the design of the control algorithm and the operational management program of a fuelcell (FC) supply system for electric bicycle is discussed. And the authors report experimental results on the fuelcell supply system and riding tests on the FC-powered bicycle.
Abstract: The paper is concerned with the design of the control algorithm and the operational management program of a fuel-cell (FC) supply system for electric bicycle. The FC delivers the electric energy to the dc link of the propulsion system through a dc-dc boost converter, which is equipped with an input filter to reduce the FC current ripple and an output supercapacitor bank to shave the power peaks. The control of the dc-dc converter is built up around two nested feedback loops of current and voltage, and meets the requirements of ripple and dynamics for the current of the FC. The operational management of the FC supply system is based on a state machine and is aimed at running the system correctly in any working condition. In addition to the design of the control algorithm and the operational management program, the paper reports experimental results on the FC supply system and riding tests on the FC-powered bicycle.
3 citations
TL;DR: In this paper, an IM speed drive with an incremental encoder and two inner loops of torque and flux implemented in a direct torque control (DTC) scheme is presented, which takes advantage of available speed to estimate the motor torque and the stator flux magnitude by means of the IM current model.
Abstract: The paper deals with an induction motor (IM) speed drive having high performance over a large speed range in the constant torque region. The drive is built up around an outer loop of speed equipped with an incremental encoder and two inner loops of torque and flux implemented in a direct torque control (DTC) scheme. The scheme takes advantage of the available speed to estimate the motor torque and the stator flux magnitude by means of the IM current model. This allows the full exploitation of the drive capabilities even in the low speed range. Furthermore, with a suitable representation of the IM current model, the drive can be operated down up to zero speed. The paper closes by analytically investigating the detuned behaviour of the scheme due to a rotor time constant mismatch. Experimental results substantiate the low-speed capabilities of the scheme and the findings on its detuned behaviour.