In BRUSHLESS INTERIOR PERMANENT-MAGNET ((IPM)) MOTORs there exists an oscillatory torque that is induced by the mutual interaction of permanent magnets mounted on the rotor and a slotted structure formed on the stator, generally called the cogging torque. This undesirable torque mainly causes vibration, position inaccuracy and acoustic noise from BRUSHLESS (IPM) MOTORs. This paper investigates the inuence of geometric parameters on the cogging torque of BRUSHLESS (IPM) MOTORs. An exterior-rotor BRUSHLESS (IPM) MOTOR, with embedded magnet poles in a V-shape, is introduced. With the aid of commercial finite-element analysis software, cogging torque waveforms of BRUSHLESS (IPM) MOTORs are accurately calculated. The effects of geometric parameters on the cogging torque, including magnet span angle of the rotor, shoe depth and shoe ramp of the stator, dummy slots notched on the stator, depth of the dummy slot and dummy slots notched on both the stator and rotor, are discussed. Ten design cases, with different values of design parameter, are presented to effectively mitigate the cogging torque. Design case X of the BRUSHLESS (IPM) MOTOR, with dummy slots on the stator, performs better than the original BRUSHLESS (IPM) MOTOR, with a 79.1% decrease in the peak value of the cogging torque.

In spite of high reliability, high torque to weight ratio and the efficiency of BRUSHLESS permanent magnet MOTORs, cogging torque and torque ripple are the main obstacles in development and application of these MOTORs. In this paper, the Taguchi experiment design method is used for reduction of cogging torque. Case study upon two types of permanent magnet MOTOR is applied for validation of this method. First type is surface BRUSHLESS permanent magnet MOTOR with 4 poles and 6 slots and second type is INTERIOR Permanent Magnet ((IPM)) MOTOR with 8 poles and 48 slots. Results from simulations indicate a considerable reduction of the peak to peak value of cogging torque.

In this research work, an improved two-dimensional semi-analytical subdomain based method for performance computation in (IPM) machine considering infinite-/finitemagnetic material permeability in pseudo-Cartesian coordinates by using hyperbolic functions has been presented. In the developed technique, all subdomains are divided into periodic or non-periodic regions with homogeneous or non-homogeneous boundary conditions (BCs), respectively. Taking into account the appropriate interfaces conditions in the presented coordinates system, the machine performances including magnetic flux density, cogging/electromagnetic torque, back-EMF, and self-/mutual induction have been calculated for three distinct values of soft-magnetic material relative permeability (viz, 200, 800 and ∞ ). The semi-analytical results are compared and confirmed by the FEA results.

The purpose of this research is to design mechanical components for making a BRUSHLESS direct current MOTOR. One-piece rotor and shaft are used in the design of this engine, and the hollow rotor is intended to access the INTERIOR space and reduce weight. Considering the magnetic flux density and taking into account the required strength of the rotor to withstand loads, 52 St steel is used and high strength epoxy pipe glue is used to connect the magnet and the rotor. In order to check the strength of the engine, engine components including power transmission parts and engine installation components were analyzed. The effect of centrifugal force on the normal stress created on the rotor, the effect of the transmission torque from the rotor in creating torsional stress on the shaft, the amount of shear stress at the connection between the magnet parts and the rotor and the amount of stress on the base parts and the required screw force. were analyzed by Nastran software to restrain the force due to the weight of the engine on the engine support bases. According to the stress analysis of the rotor and shaft, by choosing St-52 steel for these parts, a reliability of 2.58 has been obtained. The analysis of the shear stress of the connection between the magnets and the rotor indicates the proper connection of these parts by the glue used in this research with an acceptable reliability of 1.61.

In this paper, a nonlinear loss minimization control strategy for an INTERIOR permanent magnet synchronous MOTOR ((IPM)SM) based on a newly developed sliding mode approach is presented. This control method sets force the speed control of the (IPM)SM drives and simultaneously ensures the minimization of the losses besides the uncertainties exist in the system such as parameter variations which have undesirable effects on the controller performance except at near nominal conditions. Simulation results are presented to show the effectiveness of the proposed controller.

The BRUSHLESS DC (BLDC) MOTOR is a simple robust machine which has found application over a wide power and speed of ranges in different shapes and geometry. This paper briefly reviews the fundamentals behind the MOTOR and also the different types of BLDC MOTORs with different geometries and then presents a new configuration for BLDC MOTOR/generator, which does not use a permanent magnet in the rotor. The proposed novel MOTOR/generator consists of two magnetically dependent stator and rotor sets (layers), where each stator set includes nine salient poles with windings wrapped around them while, the rotor comprises of six salient poles. The magnetic field passes through a guide to the rotor then the stator and finally completes its path via the MOTOR housing. This is a three phase MOTOR/generator and every stator and rotor pole arcs are about 30o. A new power electronic converter is also presented. This topology provides bidirectional control of the current for each MOTOR phase independently. This control scheme permits the MOTOR to operate with any number of phases at any time. In this converter, four power switches in the form of a bridge connection for each MOTOR phase has been utilized therefore, the MOTOR can operate by switching different sequences for the current direction in each MOTOR phase windings and also offers the choice of having any number of phases to be on at any time. A proto-type MOTOR/generator and the drive circuit have been built and tested in the laboratory and the numerical and experimental results are presented. Due to the ruggedness of the proposed MOTOR/generator in comparison with the conventional and BRUSHLESS dc MOTORs used for automobile applications, this unit looks very promising for use as an integrated MOTOR generator for hybrid vehicle.

This paper describes a simple way to control the Brush Less DC MOTOR (BLDCM) for electrical applications. To control this machine it is generally required to measure the speed and position of rotor by using the sensor because the inverter phases, acting at any time, must be commutated depending on the rotor position. The position sensors make the MOTOR system more complicated and mechanically unreliable. A method for the estimation of the speed and rotor position of a BLDCM is presented in this work. Fuzzy based Back EMF observer is employed to estimate the speed by using measurements of the stator line voltage and line current. Most existing sensorless methods of the BLDC MOTOR have low performance at transients or low speed range and occasionally require an additional circuit. To overcome this problem, the estimation of a back-EMF is carried out by fuzzy logic techniques to improve the performance of the system. This method proposes back-EMF observer based on fuzzy function approximation and the system state equation of the BLDC MOTOR. The fuzzy logic technique is used to estimate the speed of the BLDC MOTOR under variable and fixed condition of the back-EMF. Finally, the speed is controlled by using Proportional-Integral (PI) Controller with the help of fuzzy based estimation of the speed and rotor position. Here, fuzzy based estimation of speed and rotor position which is also verified with the sensor, feeds input to the PI controller which does really well for good performance.

BRUSHLESS permanent magnet MOTORs play an important role in many applications. Power density and efficiency are two important factors in designing such MOTORs. This paper proposes a novel approach to design a BRUSHLESS permanent magnet MOTOR based on optimization of a combination of power density and efficiency. First of all, this paper presents the equation related to the design and dimensions of BRUSHLESS permanent magnet MOTOR. Then, an optimum design based on bee's algorithm (BA) with the purpose of increasing power density is presented. Finally, Simulation results of a 2-D finite element analysis have well validated the efficiency of the applied method.

The purpose of this research is thermal analysis of a BRUSHLESS permanent magnet MOTOR with marine application. The advantages of BRUSHLESS permanent magnet MOTORs are creating high torque and power in proportion to their weight and size. But this issue leads to a large increase in engine temperature. Therefore, the design of the cooling system is essential for cooling and reducing the temperature of this engine. The engine has been thermal analyzed first without cooling system and then with different cooling systems. For the purpose of thermal analysis, the stator and the shell were first modeled and then simulated. The engine has been thermally analyzed first without cooling system and then with different cooling systems. In order to check the effect of the cooling system and choose an optimal and suitable cooling system for this engine, the maximum temperature in different cooling systems with the number of 4, 8 and 12 holes, the diameter of the holes various 3, 4 and 5 mm diameters and circular and oval cross-sections have been compared with each other and with the state without cooling system. The results showed that the temperature of this engine reaches about 416 ̊c without cooling system. Also, the cooling system with 8 circular 4 mm holes has been introduced as the most suitable cooling system for this engine.