• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.4
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• pp.815-820
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• 2004

The parallel operation of voltage source inverters using stator windings of high power three-phase induction motors was proposed in this paper. Most current high power induction motors with more than 4 electric poles have their external terminals installed so that windings of each phase can be approached from the outside. High power induction motors can be driven by parallel-operating several voltage source inverters through these external terminals. This way, in case a certain inverter breaks down, the operation torque will get decreased but the system can maintain its operation with the other inverters, so it can cope more effectively with breakdowns. Moreover, by providing phase difference to the switching movements of each inverter, it can increase equivalent switching frequency, which helps achieve good characteristics such as the reduction in the ripple of output torque, the reduction in the ripple of input current, and the reduction in the size of DC capacitors. Besides, since power is divided into each inverter, it can also decrease the ifluence of EMI occurring in the system. The characteristics of the proposed method were proved through computer simulations in this paper.

• Journal of Electrical Engineering and Technology
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• v.13 no.5
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• pp.1965-1977
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• 2018

This paper proposed a regenerative braking system (RBS) strategy for battery electric vehicles (BEVs) with a hybrid energy storage system (HESS) driven by a brushless DC (BLDC) motor. In the regenerative braking mode of BEV, the BLDC motor works as a generator. Consequently, the DC-link voltage is boosted and regenerative braking energy is transferred to a battery and/or ultracapacitor (UC) using a suitable switching pattern of the three-phase inverter. The energy stored in the HESS through reverse current flow can be exploited to improve acceleration and maintain the batteries from frequent deep discharging during high power mode. In addition, the artificial neural network (ANN)-based RBS control mechanism was utilized to optimize the switching scheme of the vehicular breaking force distribution. Furthermore, constant torque braking can be regulated using a PI controller. Different simulation and experiments were implemented and carried out to verify the performance of the proposed RBS strategy. The UC/battery RBS also contributed to improved vehicle acceleration and extended range BEVs.

• Proceedings of the KIPE Conference
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• 1997.07a
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• pp.314-317
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• 1997

The purpose of this study is developing a converter which is able to convert a 300[KW] power, and is a DC power supply output a 1500[V] DC voltage for inverter driving. The power converter is driven by two converter serisely and keep a high power factor of power source. This system is haven all the characteristic of voltage source converter by having a processing ability of regenerating power. The two converters controls a PWM modulation and output voltage using a only one 16 bit DSP processor.

• 제어로봇시스템학회:학술대회논문집
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• 1986.10a
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• pp.571-575
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• 1986

The squirrel-cage induction motor can be characterized as a nonlinear and multi-input, multi-output system, and has the unmeasurable states which are the rotor currents. In this paper, the time-delayed output feedback method is applied to the speed control of induction motor driven by the current-controlled PWM inverter and its performance is investigated by using the computer simulation.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.361-363
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• 1997

Rated frequency of inverter driven induction motor for a traction system can be chosen lower or higher. Traction motor with higher rated frequency can be lighter than the lower. But the maximum torque must be checked, because it is very important for starting and acceleration and it should be reduced with high frequency operation. In the paper, two motors with different rated frequency are designed and compared.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.330-332
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• 1999

At the present, development of microelectronics technology caused an increase in using of induction motor for variable speed motor drive system instead of do motor. This paper is described the design of induction motor fed by inverter and analyzed 1.5kW motor performance using by finite element method (FEM).

• International Journal of Air-Conditioning and Refrigeration
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• v.8 no.1
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• pp.29-39
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• 2000

A series of tests were performed to verify the transient characteristics of heat pump in heating and cooling mode when operating speed was varied over the 30 to 102Hz. One of the major issues that has not been addressed so far is transient characteristics during speed modulation. The model for cycle simulation has been developed to predict the cycle performance under conditions of decreasing drive frequency and the results of the theoretical study were compared with the results of the experimental study. The simulated results were in good agreement with the experimental result within 10%. The transient cycle migration of the liquid state refrigerant causes significant dynamic change in system. Thus, the migration of refrigerant was the most important factor whenever do experimental results analysis or develop simulation model.

• Proceedings of the KIEE Conference
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• 2000.11b
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• pp.336-338
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• 2000

Recently many studies have been performed for variable speed control of induction motor. Direct Torque Control(DTC) is emerging technique for variable speed control of PWM inverter driven induction motor. DTC allows the direct control of stator flux and instantaneous torque through simple algorithm. In this paper ASIC design technique using VHDL is applied to DTC based speed control of induction motor. ASIC for DTC based speed control is designed through the description of coordinate transformation, speed controller stator flux and torque estimator, stator flux and torque controller, stator flux position detector. FSM(Finite State Machine) and inverter voltage switching vector. Finally the above system has been implemented on the FPGA (XC4052XL-PG411). Simulation and experiment has been performed to verify the performance of the designed ASTC.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1095-1097
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• 1993

The double excited induction motor has two sets of three-phase system : One is connected to the ac source to take care of energy convertion, and the other is to the inverter controlable frequency and/or magnitude of voltage, both of the induction mode and the synchronous mode are possible in double excitation motor, and the proposed double excitation motor can be driven as a synchronous motor by the extra three-phase input. At the synchronous mode the efficiency is improved so higher than that at induction mode or induction motor. The rating of the inverter used for speed control can be reduced upto one-fifth of that for conventional induction motor. Also the cost and maintenance fee of double excitation induction motor can be reduced compared to any other motors.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.187-193
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• 1998

An inverter-driven induction motor is used as the traction motor for a high speed drive system that required safty, reliability and performance and so on. rotor bar and end ring of the traction motor are the electrical equipments which form the conductive close loop and then induce current by interaction wi th the current of stator. the materials selection of rotor bar and end ring are seriously considered in the aspects of electrical and mechanical specification and Motor slip relation to inverter. Particularly motor slip guarantee the safty and reliability of induction motor. this paper show the material selection and the determining of slip in the design of traction motor for high speed train by analyzing the specifications of material being used currently.