• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2007년도 제38회 하계학술대회
• /
• pp.1132-1133
• /
• 2007

A circuit-domain model of PWM inverter provides accurate simulation results in consideration of detail switching characteristics. Although, a huge amount of computation time is demanded for the simulation results of several ten seconds, which is the required time to analyze system behaviors or control performances of Electric Power Steering(EPS) on real drive condition. This paper describes the nonlinear inverter model for fast dynamic simulation of EPS without the PWM concept through analyzing the effect of nonlinear switching characteristics like dead time, forward voltage drop and conduction resistance. Some inverter models including proposed model are compared from two standpoints which are computation time and accuracy. The comparison results show the usefulness of the developed model in order to develop the control algorithm through the fast prediction of system behaviors.

• 전기학회논문지
• /
• 제67권8호
• /
• pp.1047-1054
• /
• 2018

This paper proposed the strategies for controlling both the heater temperature and the output voltage of a single-phase inverter for the heat treatment. The single-phase inverter system for the heat treatment controls the heater temperature to its reference one, and also it limits the inverter output voltage to 60 V for safety. The stability may be deteriorated due to the large time constant difference between the heater temperature and inverter output voltage. In order to ensure the stability, a hysteresis on/off control approach for the heater temperature control is adapted, and both the open-loop and the closed-loop control strategies of the output voltage are suggested. The performances for the proposed strategies are demonstrated with the experiments.

• Journal of Electrical Engineering and Technology
• /
• 제2권2호
• /
• pp.249-256
• /
• 2007

This paper presents a new circuit topology and its digital control scheme for a half-bridge resonant inverter. As the proposed half-bridge inverter can be operated in load-freewheeling modes, the pulse-width modulation (PWM) method can be used for the output power control. The proposed half-bridge inverter is based on the resonant frequency-tracking algorithm with the goal of maintaining the unity of the output displacement factor of the load impedance even in varying conditions. In this paper, the operation principle, electrical characteristics, and detailed digital control scheme of the proposed half-bridge resonant inverter are described. The experimental results of the prototype experimental setup to verify the validity of the proposed half-bridge inverter are presented and discussed.

• 전력전자학회논문지
• /
• 제5권3호
• /
• pp.246-253
• /
• 2000

전동기의 제어기법과 제어기 등의 발달로 유도전동기는 산업용으로 널리 보급되고 있으며, 유도전동기를 고효율로 제어하기 위하여 PWM 인버터가 널리 사용되고 있다. 그리고 IGBT와 같은 고속 스위칭 소자의 발달로 인해 전압형 PWM 인버터의 스위칭 주파수가 증가가 가능하게 됐으며, 그로 인해 매우 우수한 동작 특성을 가지게 되었다. 그러나 고속 스위칭은 전압과 전류의 급격한 변화로 인해 매 스위칭마다 발생하는 고주파 성분의 커먼 모드전압과 전류를 발생하게 되고 이들은 베어링 전류와 축전압, 전도 및 방사 EMI, 기기의 절연수명 단축, 등의 악영향을 유발한다. 본 연구에서는 이러한 커먼 모드 전압과 전류에 대한 시스템 레벨 해석이 가능한 시뮬레이션 기법에 대해 실제 측정과 시뮬레이션을 통해 검정하였다. 이를 통해서 커먼 모드 전압과 전류가 PWM 인버터 시스템의 각 부에 미치는 영향을 쉽게 확인 할 수 있으며, 커먼 모드 전압과 전류의 저감을 위해 추가될 수 있는 부가적인 보조회로의 영향에 대해서도 제시된 시뮬레이션 기법을 통해 확인 할 수 있다.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1997년도 하계학술대회 논문집 F
• /
• pp.2143-2145
• /
• 1997

SV_PWM inverter for Induction motor drive system was designed at SIMULINK environment in MATLAB. This paper was performed the analysis of output current harmonics using DSP blockset. It was roved in this paper that SV_PWM method has been ore effective than triangle comparison PWM method on harmonic reduction at steady state.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1996년도 창립기념 전력전자학술발표회 논문집
• /
• pp.109-112
• /
• 1996

In this paper, we composed utility interactive photovoltaic generation system of current source inverter, and controlled that low harmonic and high power factor are hold by supposing control and compensation method which is concerned with synchronous signal distortion and modulation delay. And we put parallel resonant circuit into dc link, so, magnitude of direct reactance was reduce by restraining direct current pulsation which had accumulation of pulsating power in alternating electrolytic condenser. Also we controlled that modulation factor is operated around maximum output of solar cell.

• 조명전기설비학회논문지
• /
• 제28권11호
• /
• pp.100-105
• /
• 2014

In this paper, Uninterruptible Power Supply(UPS) Inverter system using Carrier Frequency Modulated PWM (CFM-PWM) is proposed to reduced harmonics and electromagnetic noise. Power conversion of UPS system is executed by the ON-OFF operation of semiconductor switching devices. However, this switching operation causes the surge and EMI which deteriorate the reliability of the UPS system. This Problems improved by Random PWM switching method. The simulation results of the proposed system was compared with the system using conventional method using Matlab/Simulink. The results show that the output voltage and current harmonics of the proposed UPS system significantly decreased and spread into wide band area by the proposed Carrier Frequency Modulated PWM(CFM-PWM) method based on the Space Vector Modulation.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
• /
• pp.216-222
• /
• 2003

Today we have excellent motor drive system using high frequency carrier PWM control voltage source inverter in the other hand, we have met serious problems caused by high frequency switching. PWM Cyclo-converter called Matrix converter is expected as the new strategy Possible to improve these problems and add some more convenient features suitable for new drive system. in this Paper, we will introduce the background, features and outline of this converter, and additionally introduce some remarkable activity on this converter

• 전기전자학회논문지
• /
• 제21권2호
• /
• pp.166-169
• /
• 2017

본 논문에서는 Z-소스 인버터의 최대승압 불연속 PWM 방법을 설계하였다. 일반적으로 불연속 PWM 방법은 스위칭 손실을 줄이고, 효율을 향상시키기 위하여 사용되어 왔으며 본 논문에서는 기존에 연구되었던 Z-소스 인버터의 최대승압 PWM 방법과 함께 불연속 PWM 기법을 결합하여 적용함으로써 전체 효율을 향상시킬 수 있었다. 제안된 방법은 실험을 통하여, 기존의 PWM 방법들과의 효율을 비교함으로써 효용성을 입증하였다.

• Journal of Electrical Engineering and Technology
• /
• 제10권4호
• /
• pp.1589-1596
• /
• 2015

A novel control method of a three-phase PWM inverter with LC filter is proposed. The transfer function of LC filter is the same as that of 2nd order low pass filter(2nd LPF) which has a zero damping ratio. A simple method of implementing 2nd LPF with damping ratio is to add resistor to inductor or capacitor of LC filter. In an industrial application, it is not practical to adopt damping resistor because it results in losses being proportional to square of current flowing through resistor. Instead of using damping resistors, the proposed active damping control(ADC) utilizes all pass filter(APF) and considers inherent processing delay of digital controller. The overall transfer function of the proposed method is the same as a 2nd LPF and its damping ratio is also controllable via control variables. Detailed design and implementation of controller is also presented. Experiments are conducted with a 7.5kVA induction motor drive system controlled by PWM converter and inverter. Test waveforms are also presented to verify the proposed LC filter control algorithm.