• Journal of Electrical Engineering and Technology
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• v.2 no.4
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• pp.505-512
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• 2007

The object of this paper is to study a new control structure for sensorless induction machines dedicated to electrical drives using a three-level voltage source inverter VSI-NPC. The amplitude and the rotating speed of the flux vector can be controlled freely. The scheme investigated is an Enhanced direct torque control "EDTC" for electric vehicle propulsion. The considered application imposes some constraints which are achieved in EDTC control (fast torque response, optimal switching logic, torque control at zero speed, and large speed control. The results obtained for an induction motor indicate superior performance over the FOC type without need for any mechanical sensor.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.1954-1959
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• 2014

This paper attempts to design and present a comparison of classical Direct Torque Flux Control (DTFC) for Line-Start Permanent Magnet Synchronous Motor (LSPMSM) and its equal Permanent Magnet Synchronous Motor (PMSM). In order to present an in-depth analysis, both motors for DTFC Voltage Source Inverter (VSI)-fed in the same situations of different conditions are simulated and tested. The advantages of the proposed method for LSPMSM over the PMSM are discussed and analyzed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.09a
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• pp.34-37
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• 2001

This research suggested the new algorithm controlled by micro processor which is already stored by various PWM form of output voltage by using fundamental data of the carrier and signal. The determined PWM pattern is not concerned with the signal wave form and the new algorithm can obtain the desired pulse width by synchronous of carrier. The PWM wave can be controlled with real time by using extra hardware and digital software and to speed up program processing, the control signals to switch the power semi-conductor of three phase PWM inverter, simultaneously use the output signal by microprocessor and extra hardware, and control signal by software. In the end, this method was proved by applying to Three phase voltage source inverter.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.198-199
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• 2006

FACTS(Flexible AC Transmission System) 기기들은 전력계통의 경제적이고 안정적인 운용과 제어에 더 많은 유연성을 제공할 수 있다. 그러나 이러한 FACTS 기기들은 기존의 전력 계통 설비들과는 달리 그 특성이 매우 비선형적이고 복잡하기 때문에 기존 전력 계통의 동적 시뮬레이션 알고리즘에 적용시키는 것이 매우 어렵다. 이러한 어려움을 해결하기 위하여 전압원 인버터(Voltage Sourced Inverter) 형태의 FACTS 기기를 병렬 형태로 주입되는 전류로 등가화 하여 기존의 시뮬레이션 알고리즘에 적용하는 방법이 제안되었다. 본 논문에서는 이 전류 주입형 기법을 이용하여 다수의 FACTS 기기들이 설치된 계통의 동적 안정도 해석 방법을 제안한다. 제안된 방법은 서로 다른 형태의 FACTS 기기들이 설치된 경우에도 적용될 수 있으며 이를 이용하여 서로 다른 FACTS 모델들 간의 조합에 의한 계통의 안정도 변화를 사례연구를 통하여 보일 것이다.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.23-24
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• 2014

본 논문은 전압원 인버터를 모델 예측 제어 (Model Predictive Control)를 하는데 있어 스위칭 손실을 줄이기 위한 제로 벡터 (zero-vector) 선택 방법을 제안한다. 기존의 전압원 인버터의 모델 예측 제어는 제로 벡터의 중복을 선택하는 방법이 제시되지 않아, 이에 대한 연구가 필요하다. 본 논문에서는 제로 벡터의 중복을 선택하는 방법으로 스위칭 손실을 줄이기 위한 제로 시퀀스 전압을 생성하고, 생성된 제로 시퀀스 전압의 부호를 통해 제로 벡터의 중복을 선택하였다. 따라서 전류의 품질은 그대로 유지시키는 동시에 스위칭 손실을 감소시킬 수 있다. 이를 시뮬레이션으로 검증하였다.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.203-204
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• 2012

본 논문에서는 3-레벨 ANPC 방식을 적용하여 하이브리드 자동차에 장착된 IPMSM을 구동하는 인버터를 제안하였다. 3-레벨 ANPC 인버터는 전력 반도체 스위치의 열 분배에 용이하다. 또한 3-레벨 인버터의 경우 dv/dt가 작기 때문에 THD를 감소시켜 출력 필터의 부피와 EMI를 저감 시킬 수 있다. 따라서 자동차의 신뢰성과 안전성을 높일 수 있다. 제안된 논문에서는 2-레벨 인버터와 3-레벨 ANPC 인버터 출력 특성을 분석하고, 스위치 간 온도 특성 분석 및 THD를 시뮬레이션 통하여 비교하였다.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.667-670
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• 1999

An active power filter is used to eliminate harmonic currents. This paper applied the extension pq theory to harmonic currents compensation. An active power filter based on extension pq theory is more effective than pq theory in 3-phase unsymmetrical voltage system. When extension pq theory is used, the result of simulation present source current is not distorted. Pulse-width modulation method is CRPWM(Current-Regulated PWM).

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.373-376
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• 1999

This paper propose a "common mode voltage damper" that is capable of reducing the common mode voltage produced in the PWM VSI. An push-pull circuits and high frequency leakage current damper[1] are incorporated into the "common mode voltage damper", the design method of which is presented. Effect of "common mode voltage damper" is simulated in this paper verifies the viability and effectiveness in 2.2kW induction motor drive using IGBT inverter. Simulated results show that "common mode voltage damper" makes significant contributions to reducing a high frequency leakage current.ducing a high frequency leakage current.

• KIEE International Transactions on Power Engineering
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• v.3A no.4
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• pp.206-213
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• 2003

The main purpose of this paper is to present a simulation model for assessing the impacts of a variable speed wind turbine (VSWT) on the distribution network and perform a simulation analysis of voltage profiles along the wind turbine installed feeder using the presented model. The modeled wind energy conversion system consists of a fixed pitch wind turbine, a synchronous generator, a rectifier and a voltage source inverter (VSI). Detailed study on the voltage impacts of a variable speed wind turbine is conducted in terms of steady state and dynamic behaviors. Various capacities and different modes of variable speed wind turbines are simulated and investigated. Case studies demonstrate how feeder voltages are influenced by capacity and control modes of wind turbines and changes in wind speed under different network conditions. Modeling and simulation analysis is based on PSCAD/EMTDC a software package.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1039-1041
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• 1999

Recently Advanced Static Var Compensators(ASVC) or STATic Synchronous COMpesator(STATCOM) has been considered as a next generation reactive power controller. [2] STATCOM is a voltage source inverter(VSI) based static VAr compensator with only small capacitors on the do side. The main function of the STATCOM is to keep the bus voltage magnitude at the desired value. [1] This paper compares the PAM STATCOM with PWM STATCOM. The characteristics and the control method of each model is analyzed. And the simulation of STATCOMs based on the above two methods was presented.