• Journal of Advanced Marine Engineering and Technology
• /
• v.34 no.6
• /
• pp.887-893
• /
• 2010

Modelling methods of 3 phase induction motors dependant on a lot of parameters give much drawbacks and difficulties when making engine room simulators due to computation burden and the time required for acquiring detailed technical data corresponding to actual induction motors. This paper suggests a practical method by a equivalent circuit with minimized parameters and some formulas to configure induction motors which requires only data on the name plates of motors, while it revealed satisfactory modelling performances on the resultant curves which are plotted for the torque, load current and power consume according to slip variation.

• Proceedings of the KIPE Conference
• /
• 1998.10a
• /
• pp.442-446
• /
• 1998

With the advent of the high-speed microprocessor and DSP, the possibility of executing a control strategy in digital domain has become a reality. By the use of the DSP and microprocessor controller, many high power converters such as especially inverter and motor drive system may be enhanced resulting in the improved robustness to EMI, the ability to communicate the operating conditions and the ease of adjusting the control parameters. But, the digital controller using DSP or microprocessor is not applied in the high frequency switching power supplies, especially full bridge dc/dc converter. So, this paper presents the method and realization of designing a digital-to-phase shift PWM circuit for full digital controlled phase-shifted full bridge dc/dc converter with zero voltage switching. The operating principles, simulation and experimental results will be presented.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.50 no.7
• /
• pp.315-322
• /
• 2001

High speed brushless permanent magnet(PM) machines need a key technology to minimize the iron core losses in stator and the eddy current losses in the retained sleeve and magnets caused by slotting harmonics. Thus, slotless or iron-coreless brushless PM machines have been applied for a very high rotational speed and/or the ripple-free torque. Unfortunately, slotless or coreless PM machines have lower open-circuit field than slotted and/or iron-cored types, which cause to reduce power density. Fortunately, Halbach array can generate the strong magnetic field systems without additional magnetic materials. In this paper, the 4-pole Halbach array is applied to the high speed machine and is compared with the radial magnetized PM array in field system. The iron-/air-cored stator of PM machine is constructed with/without winding slots. Open circuit magnetic fields of each type are presented from the analytical method and finite element method. Consequently, it is confirmed that the Halbach array field system with slotless stator is more suitable to the high speed motor because it has high flux density, sinusoidal flux distribution than others.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.2 no.2
• /
• pp.59-63
• /
• 1988

In a fixed AC power source the PWM techniques were used to vary the voltage and the fundamental frequency. The conventional PWM techniques due to the problem of commutation number and filter size have been studied the PWM output waveforms which applied the motor drive. However in this paper, the carrier frequency with sinusoidal PWM waveform is modulated from 10(KHz) to 45(KHz) using termination devices with high - speed switching capacity and applying LPF(Low Pass Filter) with small capacity to output of inverter and the PAM(Pulse Amplitude Modulation)is obtained. Considering the property of the speed and the control, the sinusoidal PWM control circuit was composed of the microprocessor and analog circuit. In experment result, the system properties are study on the sinusoidal voltage waveform with modulation index changing from 0.6 to 1.0.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.10 no.6
• /
• pp.550-559
• /
• 2005

The matrix converter provides sinusoidal input and output wave forms, bidirectional power flow, controllable input power factor and a long life, compared to the VSI(Voltage Source Inverter) with diode rectification stage at the input. However it has tasks, such as complexity of the control method, ride-through problem and low voltage-ratio limitation, to overcome for commercializing, This paper describes the design, construction and implementation of matrix converter based on space vector modulation technique. The implemented prototype of matrix converter is built using the exclusive IGBT module and control circuit constituted with DSP and CPLD and it has an input filter, overvoltage protection circuit and commutation means for overcoming practical issues. The good results tested using an induction motor are also presented.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.1832-1837
• /
• 2011

This paper presents the optimal permanent magnet shape on the rotor of an interior permanent magnet motor to reduce the core losses and improve the performance. As permanent magnet has conductivity inherently, it causes huge amount of eddy current losses by the slot harmonics with concentrated winding. This loss is roughly 100 times larger than that of distributed winding in high speed operation and it cannot be ignored, especially on traction motors. Each eddy current loss on permanent magnet has been investigated in detail by using FEM(Finite Element Method) instead of EMCNM(Equivalent Magnetic Circuit Network Method) in order to consider saturation and non-linear magnetic property. Simulation-based DOE(Design Of Experiment) is also applied to avoid large number of analyses according to each design parameter and consider expected interactions among parameters. Consequently, the optimal design to reduce the core loss on the permanent magnet while maintaining or improving motor performance is proposed by an optimization algorithm using regression equation derived and lastly, the core loss reduction on the proposed shape of the permanent magnet is verified by FEM.

• Journal of international Conference on Electrical Machines and Systems
• /
• v.1 no.4
• /
• pp.412-418
• /
• 2012

Eddy current brakes are electromechanical devices used as variable mechanical loads for testing electrical machines. Accurate modeling of eddy current loss is an important t factor for optimum design of eddy brake systems. In this second part, we propose novel formulations of eddy current loss in novel claw-pole eddy brake system. The proposed model for eddy current loss in novel claw-pole eddy brake system depends on the size of the claw poles. Also, in this paper, the flux density is measured by using the magnetic circuit of the novel claw pole. The model results are compared with experimental results and they are found to be in good agreement.

• Journal of IKEEE
• /
• v.20 no.2
• /
• pp.163-166
• /
• 2016

It is important to operate the driving circuit under the optimal condition through precisely sensing the power consumption causing the temperature made mainly by the MOSFET (metal-oxide semiconductor field-effect transistor) when a BLDC (Brushless Direct Current) motor operates. In this letter, a Super-junction (SJ) power TMOSFET (trench metal-oxide semiconductor field-effect transistor) with an ultra-low specific on-resistance of $0.96m{\Omega}{\cdot}cm^2$ under the same break down voltage of 100 V is designed by using of the SILVACO TCAD 2D device simulator, Atlas, while the specific on-resistance of the traditional power MOSFET has tens of $m{\Omega}{\cdot}cm^2$, which makes the higher power consumption. The SPICE simulation for measuring the power distribution of 25 cells for a chip is carried out, in which a unit cell is a SJ Power TMOSFET with resistor arrays. In addition, the power consumption for each unit cell of SJ Power TMOSFET, considering the number, pattern and position of bonding, is computed and the power distribution for an ANSYS model is obtained, and the SJ Power TMOSFET is designed to make the power of the chip distributed uniformly to guarantee it's reliability.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.4
• /
• pp.715-721
• /
• 2010

This paper deals with the design and characteristic analysis of electro-magnet/permanent-magnet (EM-PM) hybrid levitation and propulsion device for high-speed magnetically levitated (maglev) vehicle. The machine requires PMs with high coercive force in order to levitate the vehicle by only PMs, and propulsion force is supplied by long-stator linear synchronous motor (LSM). The advantages of this configuration are an increasing levitation airgap length and decreasing total weight of the vehicle, because of the zero-power levitation control. Several design considerations such as machine structure, manufacturing, and control strategy are described. Moreover, the levitation and propulsion device for high-speed maglev vehicle has been designed and analyzed usign the electromagnetic circuit and FE analysis. In order to verify the design scheme and feasibility of maglev application, 3-DOF static force test set is implemented and tested. The obtained experimental data using the static tester shows the validity of the design and analysis approaches.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.25 no.12
• /
• pp.2078-2090
• /
• 2001

This paper deals with a precise position synchronous control by a cooperative control method of two axes rotating systems. First, the system's dynamics including motor drives described by a motor circuit equation and Newton's kinetic formulation about rotating system. Next, based on conventional PID(Proportional, Integral, Derivative) control law, current and speed controller are designed very simply to follow up reference speed correctly under some disturbances. Also, position synchronous controller designed to minimize position errors according to integration of speed errors between two motors. Then, the proposed control enables the distributed drives by a software control algorithm to behave in a way as if they are mechanically hard coupled in axes. Further, the stabilities and robustness or the proposed system are investigated. Finally, the proposed system presented here is shown to be more precise position synchronous motion than conventional systems through some simulations and experiments.