Viorel Trifa

Direct electric in-wheel driving of a bicycle using reluctant motors

The paper deals with an overview regarding the implementation of individual urban transportation using reluctant motor driven electric bicycles. A particular case of Cluj- Napoca city is taken as reference. Study of opportunity, state of the art in the field of electrical driven bikes and a proposed solution for electric motorizing in this field are presented. Preliminary calculus and results are given.

Air source heat pump a key role in the development of smart buildings in future energy systems: Low cost and flexible experimental setup for air source heat pumps

An important challenge for energy systems today is reducing dependency on fossil fuels, while handling increasing penetration levels of intermittent renew abies such as wind and solar power. The efficient consumption of energy is a vital mater for a sustainable energy system. A significant part of energy is used for space heating, space cooling, and domestic hot water production which are provided to residential and commercial buildings. Air source heat pumps (ASHP) are widely used conversion technologies all over the world for providing building thermal energy services as: cooling, heating, and water heating. ASHP does not have a constant temperature for the primary source like: soil, ground water, or surface water heat pumps but still have a majority in usage. As result, laboratory experiments and tests are faced by the problem of having to handle a wide range of conditions under which the evaporator is operated. In order to cover various climate conditions, the performance and behavior of the ASHP must be tested for temperatures ranging from -30°C to 40°C and for various humidity levels. This paper presents an experimental stand, named controlled lab environment (CLE or climatic box), for testing ASHP under controlled evaporator ambient conditions. A main purpose of the CLE is to test and verify the performance and behavior of a theoretical model of the ASHP as a basis for optimization and efficiency improvements. Design considerations and schematics of the CLE are presented. Furthermore, a thermodynamic model of an ASHP is presented and simulation results.

FEM analysis of reluctant motors for direct driving of the light electric vehicles

The paper presents the aspects regarding FEM analysis of a reluctant motor for direct driving of the light electric vehicles. The reluctant motor take into study is of special construction suitable for direct drive of a light electric vehicle. It is an inverse radial reluctant motor, with a fixed stator mounted on front wheel shaft and an external toothed rotor fixed on the front wheel itself. A short presentation of preliminary design is continued with the FEM analysis in order to provide the optimal geometry of the motor and adequate windings.

Neuro-control approach of switched reluctance motor drives

The purpose of the paper is to present several studies on neural networks used for the modelling of a switched reluctance motor (SRM) with variable structure control. A positioning system using a four-phase SRM is presented, in which the position error is processed by a sliding-mode controller. The control unit represents the subject of a neural network-based model. The proposed network system has a feedforward type architecture, structured on three layers of processing units. The networks are trained using the BKP algorithm. Once the network system is trained, it is integrated as a part of the positioning system. The training and testing sets of examples are obtained by numerical simulation of the positioning system using the Matlab environment.

One-phase versus two- phase-on driving comparison of 8/6 Switched Reluctance Motor using finite element method analysis

Following a comparison to one-phase and two-phase-on, this paper brings contributions to the analysis of an 8/6 Switched Reluctance Motor (SRM). It is a common variable-reluctance motor with and internal salient 6-pole rotor, which has no conductors or magnets, and an external 8-pole stator with concentrated coils, which allows earlier winding and shorter end turns than other types of motors. Two different commutation strategies, one-phase and two-phase-on methods are discussed. The Transient Magnetic application allows the study of the phenomena created by a time variable magnetic field. In order to improve the existing model, an electrical circuit for one phase and two phase of the SRM was implemented.

A custom flexible experimental setup to test air source heat pump for smart buildings

In this paper a custom made experimental stand is presented, named controlled lab environment (CLE or climatic box), built for testing an air source heat pump (ASHP) under controlled evaporator ambient conditions and verify the performance and behavior of a theoretical model of the ASHP as a basis for optimization and efficiency improvements. While the data acquisitions from experiments are not yet available, the paper presents the design considerations and schematics of the CLE and a thermodynamic model of an ASHP.

Setting-up 3D finite element analysis of an inverse reluctance motor for driving light electric vehicles

The paper is the first attempt to 3D approach of a special reluctance motor for the implementation of individual urban transportation. The motor is of inverse construction - inner stator fixed on front wheel shaft and outer rotor linked to wheel rim. This in-wheel motor ensures fundamental requirement of a direct gearless driving the light electric vehicles - to develop high torque at low speed. First, the motor is designed using classical approach and then its model is systematically built for 3D analysis. Geometry and mesh in 2D and 3D representation are introduced as preliminary study for complete finite element analysis.

THE INFLUENCE OF DRIVE CIRCUIT PARAMETERS ON THE PERFORMANCES OF STEPPING MOTORS

The parameters of current waveforms in the phases of stepping motor are discussed. They are introduced into the equation of motion of rotor, which is used for an energy approach of stepping motor operation. A method for computation of maximum stepping rate for given values of load torque is presented.

The Influence of Drive Circuit Parameters on the Performances of Stepping Motors

Abstract The parameters of current waveforms in the phases of stepping motor are discussed. They are introduced into the equation of motion of rotor, which is used for an energy approach of stepping motor operation. A method for computation of maximum stepping rate for given values of load torque is presented.