• 한국군사과학기술학회지
• /
• 제2권2호
• /
• pp.242-250
• /
• 1999

This paper presents an estimation scheme of the external torque applied on the motor by using measured motor input current when the IPM(Interior Permanent Magnet) rotor type BLDC motor operates with constant speed. In general, the BLDC motor is controlled by vector control method. If it could be operated at over critical speed, the control scheme must be modified to flux-weakening control method. The external torque applied on the motor using flux-weakening control method could not be calculated by conventional torque equation because the demagnetizing current Id exists in the motor input current. In this paper, the commonly used flux-weakening control method is studied and the modified torque estimation scheme is suggested. The estimation scheme has been verified by the simulations and experimental results.

• 한국정밀공학회지
• /
• 제33권12호
• /
• pp.999-1005
• /
• 2016

A brushless direct current (BLDC) motor electronically performs rectification without brushes. It therefore does not have the typical mechanical friction contacts between the brushes and commutators. The BLDC motor has the advantages of high speed, low noise, and electronic noise reduction in addition to high durability and reliability. Therefore, it is mainly used in electric vehicles and electric equipment. However, iron loss and copper loss due to long-term use induce temperature increases in the motor, which reduces its performance and life. The temperatures of the stator and permanent magnet are predicted to be $62.3^{\circ}C$ and $32.2^{\circ}C$, respectively. This study shows the enhanced temperature distribution in a 600 W BLDC motor using unsteady and three-dimensional (3D) numerical investigations validated with experimental data.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1999년도 전력전자학술대회 논문집
• /
• pp.22-25
• /
• 1999

A brushless DC motor has the high quality of torque output and silence, has been more widely used in industrial area. As the driver and controller of BLDC motor have been more complicated and precise, simulation method has been much used in motor design. And the output characteristics of BLDC motor is determined by the waveform of BACK-KMF in instinct. But because the conventional model of BLDC motor is obtained by approximation of real nonlinear waveform to ideal trapezoidal waveform, the error is occurred in simulation result. Thus in this paper, for the correction of this error in simulation, the model of real nonlinear waveform considered is proposed, and the simulation result is obtained in case of three-phase, four-poles Y-connected, surface mounted permanent magnet BLDC motor.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제52권8호
• /
• pp.368-372
• /
• 2003

This paper deals with the cogging torque analysis of a BLDC Motor, which has the axial displacement of its rotor. In order to improve the torque performance of the BLDC motor, Brushless motor is commonly designed to minimize its cogging torque. Therefore, a skewed model is used to reduce the cogging torque. However, even though the rotor or stator is skewed, the cogging torque could be increased by the axial displacement of the rotor, which occurs when the BLDC Motor is manufactured. Therefore, this paper investigates the effect of the axial displacement of the rotor on the cogging torque. In order to investigate the effect, an analysis method, which is 3D-EMCN in combination with 2D-FEM, is proposed to analyze the cogging torque of the BLDC motor with the axial displacement of its rotor, and the result of the analysis is verified by comparison with the experimental result.

• Journal of Electrical Engineering and Technology
• /
• 제6권2호
• /
• pp.215-225
• /
• 2011

In this paper, a buck DC-DC bridge converter is used as a power factor correction (PFC) converter for feeding a voltage source inverter (VSI) based permanent magnet brushless DC motor (PMBLDCM) drive. The front end of the PFC converter is a diode bridge rectifier (DBR) fed from single phase AC mains. The PMBLDCM is used to drive the compressor of an air conditioner through a three-phase voltage source inverter (VSI) fed from a variable voltage DC link. The speed of the air conditioner is controlled to conserve energy using a new concept of voltage control at a DC link proportional to the desired speed of the PMBLDC motor. Therefore, VSI operates only as an electronic commutator of the PMBLDCM. The current of the PMBLDCM is controlled by setting the reference voltage at the DC link as a ramp. The proposed PMBLDCM drive with voltage control-based PFC converter was designed and modeled. The performance is simulated in Matlab-Simulink environment for an air conditioner compressor load driven through a 3.75 kW, 1500 rpm PMBLDC motor. To validate the effectiveness of the proposed speed control scheme, the evaluation results demonstrate improved efficiency of the complete drive with the PFC feature in a wide range of speed and input AC voltage.

• 전기학회논문지
• /
• 제56권7호
• /
• pp.1231-1235
• /
• 2007

This paper presents the dynamic characteristics of a linear brushless dc (BLDC) motor with permanent magnet excitation for the precision conveyor according to the load condition. Dynamic performance of the linear BLDC motor driven with 6 step inverter such as thrust force and speed is simulated by finite element method coupling with external circuit and measured for the prototype motor. The results of finite element analysis are compared to the experimental results and verify reliability.

• 전기학회논문지P
• /
• 제50권3호
• /
• pp.117-124
• /
• 2001

The aim of this paper is to develop a controller of multi-phase bipolar brushless DC (MPB BLDC) motors for an electric bicycle. A MPB BLDC motor has a Permanent magnet rotor in which the magnetic arrangement is radial to the shaft and integral to the rotor laminations. This technique concentrates flux, giving a higher flux density than a surface-mounted PM motor and increases reluctance torque. The stator of MPB BLBC motor has parallel winding, allowing multi-phase separate independent controllability. It gets much more high power than wye-connection at same low voltage. The conventional techniques of exited with modulation(EWM), bidirection control, and partial square wale control are Proposed with one H-bridge and two photo sensors per phase. The Proposed controller is satisfied for the limited speed control and designed for system stability Experimental results show the performance of the proposed controller of MPB BLDC motors for an electric bicycle.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 하계학술대회 논문집 B
• /
• pp.656-659
• /
• 2000

Recently, the skeleton type 2-phase brushless DC motor has been used in electric home appliance for low price and low energy consumption. In this paper, we analyzed a skeleton type 2-phase BLDC motor using time-step finite element method. And the validity of analysis is confirmed by measuring the flux distribution on the surface of permanent magnet and back-EMF. As well, we have calculated the dynamic characteristics of target motor considering the Hall sensor position. So, we have found the optimum switching position, and improved efficiency of 2-phase BLDC motor.

• 한국소음진동공학회논문집
• /
• 제23권2호
• /
• pp.144-151
• /
• 2013

This paper presents a result of the mechanical noise and vibration analysis as well as the electrical characteristics analysis of the permanent magnet(PM) motor according to the driving method that is Brushless DC(BLDC) drive and Brushless AC(BLAC) drive. To do that, the characteristics of the PM motor, which have the same output power but different driving method, are investigated. At that time, the characteristics such as torque, torque ripple and flux density, and so on, are obtained by finite element analysis(FEA). Besides, noise and vibration are obtained by spectrum analysis. The magnetic noise is defined as noise generated from vibrations due to electromagnetic excitation force. In this paper, the electromagnetic excitation force is analyzed and design process of noise reduction is proposed. Finally, The validity of the analysis results is verified by test.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2012년도 추계학술대회 논문집
• /
• pp.522-527
• /
• 2012

This paper presents a result of the mechanical noise and vibration analysis as well as the electrical characteristics analysis of the permanent magnet (PM) motor according to the driving method that is Brushless DC (BLDC) drive and Brushless AC (BLAC) drive. To do that, the characteristics of the PM motor, which have the same output power but different driving method, are investigated. At that time, the characteristics such as torque, torque ripple and flux density, and so on, are obtained by finite element analysis (FEA). Besides, noise and vibration are obtained by spectrum analysis. The magnetic noise is defined as noise generated from vibrations due to electromagnetic excitation force. In this paper, the electromagnetic excitation force is analyzed and design process of noise reduction is proposed. Finally, The validity of the analysis results is verified by test.