• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.3
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• pp.233-240
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• 2005

In this paper, AC electric vehicle propulsion system(Converter/Inverter) using high power semiconductor, IPM is proposed. 2-Parallel operation of two PWM converter is adopted for increasing capacity of system and the harmonic content is eliminated by the phase shaft between two PWM converters switching phase. VVVF inverter control is used a mixed control algorithm, where the vector control strategy at low speed region and slip-frequency control strategy at high speed region. The proposed propulsion system is verified by experimental results with a 1,350kW converter and 1,100kVA inverter with four 210kW traction motors.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.611-613
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• 2004

This paper is concerned with the simulation and determination of the input voltage and frequency for the optimal efficiency operation of induction motors. In general, induction motors have a specific character that operation efficiency is dropped sharply at the light roads condition. Consequently, if the induction motor is controlled by high efficiency using the VVVF(variable voltage variable frequency) control methods at optimal values, the entire system can obtain the substantial energy savings from the efficiency improvement in induction motors. In this paper, optimal slip is derived from the modeling of an induction motor and the optimal hybrid-control method is suggested by the simulation of the proposed algorithm for a 3-phase induction motor.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.5
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• pp.493-500
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• 2000

The battery charger for high speed trail car is very important power source for the purpose of safety and system stability It provides control power of VVVF, CVCF, DC/DC converter and inverter for traction motor. This paper included power circuit of the ZVZCS type battery charger for high speed trail car and battery charging algorithm. Also the optimum parallel operation of 50kW battery charger for high speed trail car, and charring control method of Ni-Cd battery illustrates validity and effectiveness through the experiments.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.181-183
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• 2004

Conventional VVVF control voltage-fed inverter of blower induction motor has advantage that very speedy response characteristics for air-harmonic. But there have bad power factor on input orient have its large volume and high error ratio over 80%. And there are very expensive by reason of using the capacitor input rectifier. In this paper, It could make the smoothing capacitor-less inverter for air-blower motor by using the instantaneous compensation PWM controller. This inverter system has small volume and value compare with the conventional VVVF control inverter for blower induction motor for air-harmonic equipment.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.249-251
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• 1994

This paper introduces an implementation of high performance voltage source inverter system based on 16bit micro-processor and DSP for the application to modem rolling stock traction system. In contrast with other industry oriented inverter system, this system requires precise control action complying with various load condition and high overload capability. An asynchronous PWM generation and 3' pulse mode technology are adopted in order to improve compliant starting torque characteristics at starting phase and soft backward-forward starting motion.

• Proceedings of the KIEE Conference
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• summer
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• pp.1205-1207
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• 2004

AC plasma power supply is used to control a ozone generator and a air pollution gas. AC plasma power supply is composed of power semiconductor switch devices and control board adapted SHE(Selected Harmonic Elimination) PWM method. AC plasma power supply with sinusoidal VVVF(variable voltage and variable frequency) is realized. Its output voltage range is from 0 [V] to 20[kV] and output frequency range is from 8[kHz] to 20[kHz]. Using proposed system, AC high voltage and high frequency discharge is tested in the DBD(dieletric barrier discharge) reactor, and the space distribution of a its non-thermal plasma is observed. In spite of the increasement of voltage and frequency, the proposed system have a stable operation characteristics. It is verified by the experimental results.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1345-1351
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• 2010

First, In this essay we research about secondary source unit(SIV)180KVA is install on VVVF direct subways for using Filter Capacitor(FC) maintenance & limit of use. Vehicle's extendly use and congestly at load for Catenary voltage and load change about output change and in SIV unit there are important device named GTO Thyristor, Power Transistor Module device become short and it often happen. We analysis the fault cause and there are effects and we know the secondary source unit in filter capacitor FC1~4 input harmonic distortion component's filtering don't do correctly so we study the capacitor extend use for the component change and the outside condition by slow property changed happen and we check before and when its fault, its difficult to measure. Finally, In this research we care for this reason and we study about capacitor maintenance through control and measure ways improvement and capacitor's life spans limit of use.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.2
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• pp.166-174
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• 1999

On-line efficiency optimization control of an induction motor drive using neural network is important from the v viewpoints of energy saving and controlling a nonlinear system whose charact81istics are not fully known. This paper p presents a neural networklongleftarrowbased on-line efficiency optimization control for an induction motor drive, which adopts an optimal slip an밍J.lar frequency control. In the proposed scheme, a neuro-controller provides minimal loss operating point i in the whole range of the measured input power. Both simulation and experimental results show that a considerable e energy saving is achieved compared with the conventional constant vlf ratio operation.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.4
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• pp.381-389
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• 2004

In this paper, it is suggested that instantaneous compensation PWM control for inverter without the smoothing capacitor Therefore, this inverter system has several advantages. It has small volume and low price to manufacture, decrease trouble rate of inverter, and has power factor correction effect because huge smoothing capacitor-less. And it has compact size control circuit to use analog integrator device. It could make the smoothing capacitor-less inverter for air-blower motor by using the instantaneous compensation PWM controller. This inverter system has small volume and value compare with the conventional VVVF control inverter.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.4
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• pp.322-331
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• 2002

In this paper, a single-phase to three-phase PWM converter topology using a single-phase half-bridge PWM rectifier and a 2-leg inverter for low cost three-phase induction motor drives is proposed. In addition, the source voltage sensor is eliminated with a state observer which controls the deviation between the model current and the system current to be zero. The converter topology is of lower cost than the conventional one, which gives sinusoidal input current, unity power factor, dc output voltage control, bidirectional power flow and VVVF output voltage. The experimental results for V/F control of 3Hp induction motor drives have been shown.