• Journal of Power Electronics
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• v.11 no.2
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• pp.173-178
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• 2011

In order to verify the performance of brushless DC (BLDC) motors, the simulation method has been widely used. The current of a BLDC motors flows on two phase windings to obtain a constant torque. However, the freewheeling current caused by the inductance component of a BLDC motor exists at the commutation point so that the current can flow on three phase windings at the same time. Due to the changes of the excited phases, the model equations are frequently changed during BLDC motor drive operation. The model equations can be also changed by the applied switching pattern since the current path in the inverter circuit changes according to switching pattern. A BLDC motor system can utilize various switching patterns for many different purposes. However, such changes of the model equations complicate the simulation procedure. In this paper, the technique to set up model equations is proposed to ease the simulation of a BLDC motor system through an inverter circuit analysis. The proposed technique will be verified using the C language. Although this method does not provide the level of detail obtainable from commercial simulation tools like PSIM or SIMULINK, it can provide an efficient way to quickly compare various conditions.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.5
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• pp.1207-1212
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• 2011

This paper presents a study on the DSP(Digital Signal Processor) controller for the PBW(power-by-wire) system using BLDC(Brushless Direct Current) servo motor pump. The PBW hydraulic actuator was realized with hydraulic pump driven by BLDC servo motor, hydraulic cylinder and controller. This PBW system needs speed control of servo motor for linear thrust action of hydraulic cylinder. This paper implements a servo controller with vector control algorithm and MIN-MAX PWM technique. As CPU of a controller, TMS320F2812 DSP was adopted because it has PWM waveform generator, A/D converter, SPI(Serial Peripheral Interface) port and many input/output port etc.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.3
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• pp.191-198
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• 2007

This paper proposes the instantaneous source voltage and phase current control for torque ripple reduction of a high speed miniature BLDC motor. As compared with general BLDC motor, a high speed miniature BLDC motor has a fast electrical time-constant. So the current and torque ripple are very serious in a conventional PWM switching during conduction period. In order to reduce the switching current ripple, instantaneously controlled source voltage is supplied to the inverter system according to the motor speed and load torque. In addition, the fast hysteresis current controller can keep the phase current In the limited band. The proposed method is verified by the computer simulation and experimental results.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.3
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• pp.130-138
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• 2010

The thermal reliability of the closed-type BLDC motor for the high speed axial fans is analyzed by a numerical method in this paper. Since the module and the motor part are combined in a closed case, the heat generated from a rotor in the motor and the electronic components in the PCB module can not be effectively removed to the outside. Therefore the module will easily fail by high temperature. The accelerated-life testing was accomplished to formulate the life equation and numerical method is used to predict the inside temperature of the PCB module, which is one of the life equation parameter according to the environment. When the environment temperature of BLDC motor is 21, 35 and 50 $^{\circ}C$, the temperature in the PCB space is predicted as 73.4, 87.5 and 102.4 $^{\circ}C$. Then the life time with the temperature are calculated as 2,239, 863 and 328 hours.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2540-2545
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• 2007

A computational study of BLDC motor is presented to elucidate thermo-flow characteristics in winding and bearing with heat generation. Rotation of rotor and blades drives influx of ambient air into the rotor inlet and the inflow rates are predicted more at the front-side inlet than at the rear-side, which can be ascribed to the different pressure distribution. Recirculation zone appears in the tiny interfaces between windings, however, showing the enhanced cooling performance due to the higher velocity distribution near the rotor wall. In contrast, flow separation and incline angle of bearing groove, and relatively slower velocity distribution cause poor cooling performance and therefore the redesign of the bearing groove is significantly required.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.77-79
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• 2004

This paper presents a design and characteristics analysis of interior permanent magnet (IPM) type BLDC motor for electric vehicle. In order to design of IPM type BLDC motor, surface mounted permanent magnet(SPM) type BLDC motor is used as the initial design model. According to the size of permanent magnet, the steady state characteristics is analysized by equivalent magnetic circuit method. The characteristics analysis results of the designed motor is compared with the experimental results.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.231-234
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• 2008

The permanent magnet BLDC motors are increasingly being used in high performance applications due to the high torque density and simplicity in their control. In this paper, the control system of the BLDC motor is developed which can be used for the micro motor handpiece, and position sensorless control is realized using back EMF measurement scheme, The validity and practical applications of the developed slotless BLDC motor and drive system are verified through the experimental results.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.135-137
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• 2002

Many application in robotics, telecommunication, automation systems etc require powerful actuator. The powerful actuator have Speeds up to high speed and high output torque efficiencies. To accomplish a powerful actuator, these powerful motor have to be combined with gearheads of the same outer diameter. So, we have developed BLDC motor and planetary type gearheads as powerful actuator. The BLDC motor have advantages that compact structure, high efficiency, high reliability. The Planetary type gearheads have advantages that same-axle structure, high torque transmission, low noise in comparison with spur gearheads. In this study included BLDC motor and planetary type gearheads design, manufacture. This time study peformed for actuator of entertainment robot.

• Journal of the Korean Magnetics Society
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• v.26 no.3
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• pp.86-91
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• 2016

The cogging torque of a brushless dc (BLDC) motor results from the interaction between permanent magnets and iron core, and it causes noise and induce vibrations. During a manufacturing process, assembly tolerances lead to the change of the electromagnetic structure of a BLDC motor where permanent magnets are not properly glued to the surface of rotor core. In this paper, the effect of magnet separation from the surface of rotor core on the cogging torque is investigated due to assembly tolerance. The relationship with key design parameters is considered such as separation between magnets and rotor core, the number of magnets having separation, as well as the several types of arrangements among neighboring magnets. Finite element method (FEM) has been used to analyze a BLDC motor, and the allowable assembly tolerance is proposed to prevent generating noise and vibrations. Within proposed assembly tolerance, it is concluded that the cogging torque of a BLDC motor is decreased, and hence noise and vibrations.

• Journal of Electrical Engineering and Technology
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• v.10 no.1
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• pp.188-194
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• 2015

This paper proposes a generalized regression neural network (GRNN) based algorithm for data interpolation and design optimization of brushless dc (BLDC) motor. The procedure makes use of magnet length, stator slot opening and air gap length as design variables. Cogging torque and average torque are treated as performance indices. The optimal design necessitates mitigating the cogging torque and maximizing the average torque by varying design variables. The data set for interpolation and ensuing design optimisation using GRNN is obtained by modeling a standard BLDC motor using finite element analysis (FEA) tool MagNet 7.1.1. The performance indices of the standard motor obtained using FEA are validated with an experimental model and an analytical method. The optimal design is authenticated using particle swarm optimization (PSO) algorithm and the performance indices of the optimal design obtained using GRNN is validated using FEA. The results indicate the suitability of GRNN as an interpolation and design optimization tool for a BLDC motor.