• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.6
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• pp.299-305
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• 2006

In this paper, we suggest a new space vector PWM modulation method with very short processing time which does not need identification of nearest three vectors(NTV) and duty ratio for each vector. The suggested PWM method makes mean value of phase voltage to be same as reference during every modulation period by use of a triangle in small hexagon on multi-level vector space. This paper described the suggested modulation method can be successfully applied to the space vector modulation use of multi-level inverter by computer simulations and experiments.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.501-503
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• 1996

In this paper, a novel control strategy for PWM current source converter and inverter is proposed, applying a multivariable state feedback control. The PWM converter controls line current to be sinusoidal and make input power factor unity. In addition, the modulation index control of dc link current is carried out, which produces lower loss of switching devices. Since the voltage control of inverter output filter capacitor is performed a decoupling of the d-q current of the induction motor is well retained. With the proposed algorithm, both high dynamic responses and satisfactory static performance can obtained.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.154-156
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• 2003

3상 4레그(leg) VSI(Voltage Source Inverter)는 독립된 3개의 출력전압을 합성할 수 있다. 따라서 전압 합성에 있어서 3개의 자유도를 갖는다. 본 논문에서는 3상 4레그 VSI를 위한 PWM방법에 대해서 설명한다. 3상 4레그 VSI를 위한 기존의 PWM기술은 3-D SVPWM으로 그 구현 방법에 있어서 많은 양의 계산과 테이블을 필요로 하였다. 하지만, 본 논문에서 제안 한 방법은 3상 3레그 VSI경우에 적용되었던 옵셋(offset) 전압의 개념을 사용한다. 또한 단일 반송파를 이용하여 폴(Pole)전압과 비교함으로써 PWM을 구현하기 때문에 그 적응이 매우 간단하다. 본 논문에서는 기존의 3-D SVPWM과 제안한 방법이 해석적으로 동일한 방법임을 증명하였으며, 3상 4레그 VSI에서 합성가능한 3자유도의 전압범위를 계산하였다. 마지막으로 이를 실험을 통하여 검증하였다.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.37-39
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• 2004

This study investigates the characteristic analysis of Line-start Permanent Magnet Synchronous Motor considering PWM Inverter. The effects of the PWM inverter on machine characteristic are analyzed by using direct co-simulation of Matlab Simulink and Flux2D. Validity of analysis method is confirmed by the analysis result of Sin-wave power Model.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.1206-1210
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• 1992

To satisfy the requirements of a stable speed control, comfortable ride and precise landing in the high-speed elevator. The induction motor driving elevator is controlled by inverter using vector control method which calculates optimum torque to apply to the Induction motor. This paper describes the control system of high-speed elevator that consists of the voltage-type PWM converter with an unity input power factor and sinusoidal input current and the voltage-type PWM inverter with a precise speed control and sinusoidal output current. The test results of actual elevator are presented.

• Journal of Electrical Engineering and Technology
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• v.11 no.2
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• pp.393-404
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• 2016

In this paper, a carrier-based pulse with modulation (PWM) strategy for three-phase three-level inverter is dealt with, which can keep the common mode voltage constant with minimized switching frequency. The voltage gain and the switching frequency in overall operating ranges including overmodulation are investigated and the analytic equations are presented. Finally, the leakage current reduction effect is confirmed by carrying out simulation and experiment. It will be pointed out that the leakage current cannot be perfectly eliminated because of the dead time.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.1914-1920
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• 2014

In this paper, characteristics of blushless direct current (BLDC) motor including core loss are analyzed considering pulse width modulation (PWM) of inverter. Input voltage of BLDC motor due to PWM is calculated considering duty ratio and carrier frequency of inverter in order to control torque or speed of BLDC motor. For the calculation of core loss, the input current with harmonics due to PWM voltage is calculated by using equivalent circuit model of BLDC motor according to switching pattern and carrier frequency. Next, core loss is analyzed by inputting the currents as a source of BLDC motor for FEM. Characteristics including core loss are compared with ones without PWM waveform according to reference speed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.10a
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• pp.553-557
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• 2000

This paper proposes the method to reduce output leakage current in single phase induction motor driven a PWM inverter. A proposed method applies to a new PWM switching algorism to reduce low-order harmonic in an inverter system with a feedback circuit of leakage current. Simulation is done to confirm a validity of method Proposed.

• Proceedings of the KIPE Conference
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• 2004.07a
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• pp.415-419
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• 2004

The U filter has been generally used to filter the output voltage of PWM inverter to the sinusoidal waveform. The resonant voltage on the output voltage of PWM inverter may be generated due to LC filter. This paper proposed the algorithm to damp the resonant voltage using the virtual resistor without decreasing the efficiency by the power loss in the real resistor The method is appled to the vector controlled induction motor driven by the PWM inverter with the LC filter. The simulation results are carried out to verify the performances of the proposed algorithm.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.225-227
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• 2008

This paper deals with the implementation on a Field Programmable Gate Array (FPGA) of PWM switching patterns for a voltage multilevel inverter. The reference data in main microcontroller is transmitted to the FPGA through 16 general purpose I/O ports. Herein, three-phase reference voltage signals are addressed by the last 2-bit (bit 15-14) and their data are assigned in remaining 14-bit, respectively. The carrier signals are created by 16-bit counter in up-down counting mode inside FPGA according to desirable topology. Each reference signal is compared with all carrier signals to generate corresponding PWM switching patterns for control of the multilevel inverter. Useful advantages of this scheme are easy implementation, simple software control and flexibility in adaptation to produce many PWM signals. Some simulations and experiments are carried out to validate the proposed method.