Synchronous Electric Motor Research Articles

Ultracapacitors equipped hybrid electric MicroCar

The main purpose of the study is to describe a small size hybrid vehicle having ultracapacitors (UCs) as on-board storage unit. The vehicle on-board main power supply is achieved by a genset being formed of a 250 cc internal combustion engine and a permanent magnet (PM) synchronous electric generator, whereas four 16 V-500 F UCs modules are connected in series in order to supply as well to store the power peaks during, respectively, acceleration and braking vehicle modes of operation. The traction power is provided by a PM synchronous electric motor, whereas a distributed power electronic interface is in charge of all the required electronic conversions as well of controlling the operating conditions for each power unit. The study discusses the implemented control strategy and shows experimental results on the modes of operation of both generation unit and storage unit.

Ultracapacitors for fuel saving in small size hybrid vehicles

The main purpose of the paper is to describe a small size hybrid vehicle having ultracapacitors as on-board storage unit. The vehicle on-board main power supply is achieved by a genset being formed of a 250 cm 3 internal combustion engine and a permanent magnet synchronous electric generator, whereas 4 16V-500F ultracapacitors modules are connected in series in order to supply as well as to store the power peaks during respectively acceleration and braking vehicle modes of operation. The traction power is provided by a permanent magnet synchronous electric motor, whereas a distributed power electronic interface is in charge of all the required electronic conversions as well of controlling the operating conditions for each power unit. The paper discusses the implemented control strategy and shows experimental results on the modes of operation of both generation unit and storage unit.

Mathematical model of rotary table in control problems

Automatic control of a precision rotary table is complex. At a positional precision of 3 ″ , elastic deformation and free play have a significant influence on table operation. Correct synthesis of the automatic control system for such a table calls for a mathematical model that takes account of the characteristics of the executive mechanism and the type of electric motor. Kinematically, the SK36-1202 table contains a worm transmission, which transmits motion from the synchronous electric motor (with permanent magnets on the rotor) to the face plate. The motor is connected to the worm shaft by a clutch. As an object of control, the table is nonlinear and nonsteady. It is characterized by frictional forces, which perturb the machining process; free play in the worm transmission; and the accumulated gear error. The free play permits thermal compensation in machine-tool operation and is at least 15 ″ . The accumulated error of the worm gear is 10 ″ ‐15 ″ . In developing a mathematical model of the table’s executive mechanism, we make the following assumptions [1]. 1. The executive mechanism is subject only to elastic forces.

An At-All Operating Points Highly Efficient PMSM for HEV

Average losses of the electric drive throughout a driving cycle are an important issue for hybrid electric vehicles. Permanent magnet synchronous electric motors (PMSM) are the most efficient electric drives under load conditions. However, they suffer from idle losses at high speed and low load, which is a typical operating condition in highway cycles. This leads, in some cases, to even higher fuel consumption of HEV vs. conventional vehicles.As well designed permanent magnet machines for HEV usually have excellent efficiency at operating points close to their rating, the main focus of the presented work is achieving an improvement in no load and reduced load conditions. Such losses will occur at high speed and low load, because the PMSM creates an induced voltage exceeding the battery voltage, which must be compensated by an inductive voltage drop through the motor inductance by a purely reactive current causing losses.A proposal for a special design for PMSM with regard to the ability of active reduction of those losses at high speeds is made in the following comment: The compensation current depends on the motor inductance. Obviously, a high inductance in the axis of magnetization needs a low compensation current, whereas a low inductance in the quadrature-axis results in a large constant power range. So a special design of an asymmetrical PMSM has been developed in order to achieve minimum idle losses.

The passage through resonance of synchronous electric motors mounted on an elastic base

It is proved that the Sommerfeld effect does not occur for any passage through resonance for a synchronous electric motor with an asynchronous start-up, mounted on an elastic base.

Magnetically hard materials for the motors of synchronous hysteresis electric motors

Magnetically hard materials for the motors of synchronous hysteresis electric motors

The calculation of stepper and synchronous electric motors for automobile electric drives

Peculiarities of calculations for electric motors for automobile electric drives integrated with electronic controls are considered.

Developments and technical potentials of new types of synchronous electric motors for the takeup-winding units of spinning machines

The results of development of new synchronous motors with permanent magnets and synchronous-hysteresis motors by the Moscow Energy Institute are examined. The results of testing them in comparison to synchronous-reluctance motors are reported. The potentials and advantage of synchronous-hysteresis motors in conditions of regulating excitation for driving the inertia! mechanisms of spinning machines are demonstrated.

The use of soft magnetic composite materials in synchronous electric motor

This paper presents some aspects of soft magnetic composite (SMC) material application in synchronous electric motors (SEM). The presented stator core of the SEM was made of two types of soft magnetic materials: the classical laminated silicon iron sheets and the SMC material. First, the stator core made of SMC, which was of the same shape as the laminated core, was analysed. The next step was to search for the optimal shape of the core. The comparison of both cores includes the calculated torque, magnetic conditions and simplicity of fabrication. The 3D FEM was used to analyse the magnetic conditions and the calculated torque. The design and the analysis were validated by experimental results obtained on the prototype.

Instructional Overview of IEEE 1349-2001—Guide for the Application of Electric Motors in Class I, Division 2 Hazardous (Classified) Locations

This work presents an overview of IEEE 1349-2001, a Guide that assists individuals, organizations, and suppliers with the application of motors in Class I, Division 2 locations, where flammable gases and vapors may occasionally be present. Three-phase and single-phase ac synchronous and induction electric motors in sizes from fractional horsepower through 10 000 hp and beyond are covered in the Guide. Primary emphasis is on the use of general-purpose enclosures and precautions against excessive surface temperatures and sparking of rotor bars and enclosure joints. The Guide also provides guidance for maintaining the life-cycle integrity of motors in Division 2 locations. Existing codes and standards, such as the National Electrical Code, contain cautionary notes for general-purpose motor applications in Division 2 areas. This Guide documents industry experience and established practices for the application of general-purpose motors in Division 2 locations and provides guidance for applying motors in these locations. It is not a specification and is not intended to be used as a specification for purchasing motors installed in Division 2 locations. This paper does not replace the Guide, but should be used to supplement and understand the Guide. Significant motor temperature information is contained in the Guide including maximum recommended Division 2 exposed surface temperatures at full load. Manufacturers, users, and other industry experts worked about eight years to develop this consensus standard. It was approved by the IEEE-SA Standards Board in December 2001 and published in June 2002.

Study of ways of reducing energy consumption in a ventilation system

For new mines with a large volume of excavation work and large loads at the face, most (up to 80%) of the methane is removed from the fragmented coal and newly exposed material in the course of mining operations. Studies of the dynamics of methane emission show that the quantity of air supplied to thin and remove methane may be reduced by a factor of 2-2.3 during offdays and unworked shifts. In connection with this, a significant savings of electric power can be realized (as will be demonstrated below) by developing regulable axial-flow ventilation fans that can be reversed during operation by rotation of the rotor vanes in order to regulate air flow by shift. The use of automatic control systems to start the synchronous electric motors of these fans would be an important additional means of energy conservation. From 10 to 15 tons of air is sent into a mine by a ventilation system for each ton of minerals extracted. The cost of the electric power used for ventilation now amounts to 20% of the total cost of mined coal. These figures will rise as mines are worked to greater depths and the cost of electric power increases. The amount of electric power consumed for ventilation is determined mainly by the amount of air required per unit of time (m3/sec) to safely thin and remove harmful impurities (methane, oxides of nitrogen and carbon, etc.) and by the aerodynamic resistance of the mine's ventilation system. These factors in turn depend on the length, cross section, configuration (topology) and type of support of the individual workings (aerodynamic resistance) and the efficiency of the main ventilation system (MVS) of the mine. The efficiency of the MVS is determined by the smile efficiency of the fans used for the specified productivity and pressure, the efficiency of the electric drive of the fans, and losses of energy (pressure, productivity -- leaks and air infiltration in the different elements of the ventilation system (calorifier, the inlet and outlet sections of the fans, diffusers, traps, plate dampers, rotating bends, etc.). Let us examine ways of reducing electric power consumption by influencing two of the three main factors that affect this characteristic: by regulating fan operating regime while the fan is operating; by automatically controlling the excitation of the synchronous motor of such fans. The required rate of air flow is determined as

Somatosensory evoked potentials elicited by air-puff stimuli generated by a new high-speed air control system

Sharp-fronted air-puffs (a rise-time of 1 msec) generated by the new high-speed air control system were used for eliciting SEPs. This system employs a rotating disk driven by a synchronous electric motor for high-speed control of air flow from a compressed air source. The air-puff is reproducible and its pressure wave form can be varied. SEPs to air-puffs or electrical stimulations of the right hand recorded from the contralateral parietal scalp had similar wave forms, but SEPs to air-puffs showed longer latencies (1–4 msec) and smaller amplitudes than those to electrical stimuli. The amplitude of early components in air-puff SEPs was on average 30% of that in electrical SEPs, but later components reached up to about 90%.

The stabilization of convective fluid stability in a cubic cavity by rotation

Experiments were performed using the same model and method as described in [i]. The cavity was rotated around its vertical axis of symmetry by a synchronous electric motor using a toothless frictional drive. During the time of the experiment the velocity of rotation was maintained constant with an accuracy of I~~ Temperature measurements were carried out on the rotating model in a quasi-steady cooling regime, in which a vertical temperature gradient was created at the beginning of the experiment. Heat transfer curves N - 1 = f(Rl, where N is the Nusselt number, were constructed for each velocity of rotation. The critical Rayleigh number was determined from the discontinuity of these curves.

A photo-electronic phase-measuring microscope.

SYNOPSISThe usual manual compensator of a double‐refracting interference microscope is replaced by a modified version which is continuously driven by a synchronous electric motor. The resulting phase excursions cover a range of a complete light wave‐length and are linearly related to time, so that the light intensity discharged by the microscope fluctuates sinusoidally. When an optical‐phase object in the interference microscope system displaces the phase relationship between the two interfering beams, the resulting phase displacement of the sinusoidally fluctuating light intensity causes the sinusoidal voltage from a photodetector to suffer an equal and corresponding phase displacement. This last displacement is transformed into a directly phase‐proportionate voltage or pulse duration by means of an electronic phase‐measuring circuit.

Composite Water‐Sampling Device

This article describes a sampling device for the chemical analysis and evaluation of a water supply that is constructed by connecting a synchronous electric motor to an overflow pipet and samples the water at periodic intervals. With a motor that rotates at an appropriate rate and a pipet that delivers an appropriate volume, this sampling device delivers a composite sample of desired volume over a given period. The sample comes into contact with only glass or Teflon parts of the device.

A Simple Weissenberg Goniometer

A simple Weissenberg goniometer is described in which only essential features are incorporated. These are (1) a movement effected by a small synchronous electric motor giving the camera (radius 3 cm.) a translation of 1 mm. per 2° rotation of the crystal; (2) a low-power microscope on an adjustable mounting enabling the crystal to be centred on the usual goniometer head; (3) an X-ray aperture system on an adjustable mounting.