• The Transactions of the Korean Institute of Power Electronics
• /
• v.10 no.3
• /
• pp.233-240
• /
• 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 KIPE Conference
• /
• 2013.11a
• /
• pp.208-209
• /
• 2013

본 논문에서는 PWM 정류시스템의 간소화, 안정화, 비용상승의 문제점을 해결하기 위한 4스위치 3상 Z-소스 PWM 정류기의 센서리스 제어 기법을 제안하였다. 제안한 정류기는 입력단 전원전압 센서 없이 입력전류 센서와 DC-link단 전압센서 만을 이용하여 전원전압을 추종하고 DC-link 전압제어를 구현 하였으며, 이를 PSIM 시뮬레이션을 통하여 검증하였다.

• Journal of the Korean Society for Precision Engineering
• /
• v.12 no.7
• /
• pp.138-147
• /
• 1995

The conventional PWM method, which was used in controlling the on-off valve, such as high-speed solenoid valve, was modulating the width of the pulse applied to the valve, by selecting arbitrary sampling time and modulating the duty-ratio in proportion to the error. However, in this method, a selection of long sampling time was inevitable and it was unable to get a high accuracy and a quick response. This study is for designing an appropriate controller for high-speed solenoid valve by proposing an improved duty-ratio modulation method using the Saw-toothed Carrier Wave which enables a short sampling time selection, high accuracy of control, and a quick response. Test which was carried out in the laboratory shows that transient and steady state response could be improved by PID controller.

• Proceedings of the KIPE Conference
• /
• 2011.07a
• /
• pp.342-343
• /
• 2011

본 논문에서는 친환경 자동차, UPS 시스템 등 배터리와 같은 에너지 저장장치의 충 방전을 위한 3상 양방향 DC-DC 컨버터를 제안한다. 제안하는 컨버터는 PWM+위상제어방식으로 동작하고 모든 스위치 ZVS 턴온을 성취하며 기존 위상제어 컨버터와 PWM 푸시풀 컨버터보다 낮은 전류정격을 갖는 특징이 있다. 기존 컨버터와 비교하여 이론적 분석을 제시하였고 시작품을 통해 타당성 및 성능을 검증하였다.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.905_906
• /
• 2009

본 논문은 한전 전력연구원이 주관하고 명지대학교와 (주)효성이 참여하는 연구과제의 결과물로써 다중펄스 컨버터와 PWM 컨버터로 구성된 20MVA급 Back-to-Back STATCOM의 시스템 구성 및 제어 동작특성에 대하여 정리하였다. 한전 전력연구원과 (주)효성이 국책과제를 통해 순수 국내기술로 개발한 10MVA급 다중펄스 STATCOM의 활용방안으로 10MVA급 PWM STATCOM 1기를 추가하여 두 STATCOM 각각의 DC link단을 연계시킨 20MVA급 Back-to-Back STATCOM을 구성하고 제어 알고리즘을 개발하였다. 또한 PSCAD/EMTDC 소프트웨어를 이용하여 개발한 Back-to-Back STATCOM의 제어 및 동작특성을 분석하였다.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.3 no.4
• /
• pp.382-387
• /
• 1998

The adaptive hysteresis band current control method using neural network is proposed to hold the switching frequency of PWM inverter constant at any operating points of ac motor. The adaptive hysteresis band equation is derived as the teaching signal of neural network. and then the structure and learning algorithm of the neural network a are suggested. The simulation results show that the switching frequency of PWM inverter is held constant at any operating conditions of ac motor and the proposed method has good transient performance of stator current.

• Journal of Institute of Control, Robotics and Systems
• /
• v.8 no.2
• /
• pp.97-103
• /
• 2002

This paper deals with a PWM(Pulse Width Modulation) current amplifier using digital controller in order to generate a gradient magnetic field far the MRI(Magnetic Resonance Image) system. Because of tolerance of discrete devices, it is difficult to set accurate values of the control parameters and to make an analog-controlling circuit. However, using digital controller, it is possible to set exact control parameters and to adopt a modern control techniques. It is shown that the digital controller will highly enhance the output current response and it will improve the quality of the MRI.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.28B no.12
• /
• pp.38-50
• /
• 1991

A current-controlled scheme of pulse width modulation voltage source inverter (PWM VSI) has attracted considerable attention due to its fast response with current limit and especially suitable for potentially high performance applications such as AC motor drives and UPS systems. These features yield near-sinusoidal currents in the load with reduced current peaks, lower inverter switching frequency and reduce inverter and load stresses. A high performance current-controlled inverter must have a quick response in transient state and low harmonic current in steady state. This paper compares and shows the controlled-characteristics with hysteresis controller(HC), ramp comparison controller(RCC) and predictive controller(PC) of PWM inverter to control actual current of VSI-IM.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.7 no.6
• /
• pp.1072-1077
• /
• 2006

In this paper a novel 3-phase line interactive UPS(Uninterruptible Power Supply) system with parallel-series active power-line conditioning capability using AC line reactor and two four-leg PWM VSCs(Voltage Source Converters) is proposed. And the strategy of voltage control in proposed UPS system is explained. The objective of voltage control in parallel(shunt) and series PWM VSC of proposed UPS system is to guarantee satisfactory characteristics in steady state and transient state.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.13 no.5
• /
• pp.352-359
• /
• 2008

This paper proposes a current compensation method of a three phase PWM converter. The phase angle of utility voltage is essential to control a PWM converter. In the case of using synchronous reference frame PLL to detect the phase angle of the distorted source, harmonics of source voltage cause the phase angle to be distorted. PWM converter control by the distorted phase angle results in input current harmonics. This paper proposes a current compensation method which can limit THD of Input currents below to 5% that is the harmonic current requirements by IEEE std. 519. Its validity is verified by simulation and experiment.