• 설비공학논문집
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• 제15권7호
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• pp.551-556
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• 2003

The present study concerns an experiment on the heating characteristics of a system air-conditioner (A/C) using PWM method or inverter method at low temperature con-ditions. The compressors used are digital scroll type and BLDC inverter type. Under the low outside temperature condition, -5$^{\circ}C$, -1$0^{\circ}C$, -15$^{\circ}C$, heating capacities and COPs are mea-sured by the psychometric calorimeter using air enthalpy method. Also, outlet air temperatures at heating operation mode are measured at -5$^{\circ}C$, -1$0^{\circ}C$ and -15$^{\circ}C$. Experimental results show that COPs of the system A/C using a PWM method are more effective than those of the inverter method at heating operation mode. Although the heater is on, COPs of PWM method are similar to those of BLDC inverter method. Moreover, the heating capacities of PWM method at -5$^{\circ}C$, -1$0^{\circ}C$ and -15$^{\circ}C$ are larger about 10~20% and outlet air tempe-rature at -15$^{\circ}C$ is larger about 10%, compared to the inverter method.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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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.

• 전기전자학회논문지
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• 제23권4호
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• pp.1182-1186
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• 2019

본 논문은 ADC 컨버터 내장 단상 직입구동 20W BLDC 모터 개발 및 출력 특성에 대한 연구결과를 논하였다. PWM 인버터 스위칭을 통해 회전자를 구동시키고, 모터의 역기전력을 홀센서 위상각 신호보다 전기적으로 30° 앞서도록 위치시켜 최적의 스위칭 타임을 확보하도록 제작하였다. 특성평가의 주요한 결과로서 인버터 효율 최대 92[%], 시스템 효율 53.34[%]를 보였으며, 모터 효율은 57.85[%] 보였다.

• 전기학회논문지P
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• 제58권4호
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• pp.391-396
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• 2009

In this paper, a control algorithm for DC-Link voltage unbalancing compensation of a four-switch inverter for a three-phase BLDC motor drive is proposed. Compared with a conventional six-switch inverter, the split source of the four-switch inverter can be obtained by splitting DC-link capacitor into two capacitors to drive the three phase BLDC motor. The voltages across each of two capacitors are not always equal in steady state because of the unbalance in the impedance of the DC-link capacitors $C_1$ and $C_2$ or the variable current flowed into the capacitor's neutral point in motor control. Despite the unbalance, if the BLDC motor may be run for a long time the voltage across one of the capacitors is more increased. So the unbalance in the capacitors voltages will be accelerated. As a result, The current ripple and torque ripple is increased due to the fluctuation of input current which flows into 3-phase BLDC motor. According to that, the vibration of motor will be increased and the whole system will be instable. This paper presents a control algorithm for DC-Link voltage unbalancing compensation. The sampling from the voltages across each of two capacitors is used to perform the voltage control of DC-Link by using the feedforward controller.

• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.295-303
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• 2013

This paper reports an investigation of pulse width modulation (PWM) techniques for two-phase brushless DC (BLDC) motors fed by a two-phase eight-switch inverter in a fan application. The three-phase BLDC motor is widely applied in industry; however, a lower-cost two-phase BLDC motor and drive circuit has been greatly in demand in recent years. In this paper, we introduce a mathematical model of the two-phase BLDC motor with sinusoidal back electromotive forces (EMFs) based on traditional three-phase BLDC motors. To simplify the drive algorithm and speed up its application, we analyze the principle of block commutation for a two-phase BLDC motor drive in the 180-electrical-degree conduction mode, and we further propose five PWM schemes to improve the commutation performance of the two-phase BLDC drive. The effectiveness of the proposed PWM methods is verified through experiments.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2014년도 추계학술대회 논문집
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• pp.33-34
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• 2014

In this paper, the inverter switch losses of BLDC motor for three types of PWM method and power devices was analyzed. When BLDC motor is driven at low currents, inverter switch losses for MOSFET is low because MOSFET operates like resistance. But, inverter switch losses for IGBT is higher than MOSFET due to its large turn-off losses. For low power inverter with MOSFET, the power losses of unified PWM is lower than that of unipolar and bipolar PWM.

• 전력전자학회논문지
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• 제11권2호
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• pp.164-171
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• 2006

본 논문에서는 BLDC 전동기 구동용 인버터의 한 상에서 개방된 형태의 스위치 고장이 발생하여도 구동 시스템의 제어 성능을 유지하기 위한 고장 허용 시스템이 제안되었다. 고장의 확인 방법은 실제 전류와 기준 전류의 오차를 이용하는 방법과 인버터 하단에 전압센서를 추가하는 방법 등 두 가지 형태가 제안되었다. 시스템의 재구성 방법은 고장이 발생한 상을 양방향 스위치에 의해 직류-링크 중성점과 연결하여 4 스위치 구동의 형태로 구성하였다. 제안한 고장 허용 시스템은 짧은 고장 검출 시간과 시스템 토폴로지의 재구성에 의해 고장 발생 후 제어 성능을 빠르게 회복하여 연속적인 시스템 운영이 가능하다. 제안한 고장 허용 시스템의 우수한 성능은 시뮬레이션을 통하여 검증하였다.

• 한국인터넷방송통신학회논문지
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• 제23권5호
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• pp.139-144
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• 2023

토크, 효율 등 전동기의 최대특성을 얻기 위해 모든 전동기는 각 전동기 특성에 맞게 설계된 범용인버터를 기본적으로 사용한다. 그러나 최근 연구 결과들을 살펴보면 BLDC 범용인버터인 6-스위치 인버터를 이용한 SRM 구동 연구, 3상 BLDC 전동기를 4-스위치 인버터를 이용한 구동 연구사례들을 살펴볼 수 있다. 따라서 기존 범용인버터에서 벗어나 각 전동기를 구동할 시킬 수 있는 구동 및 제어에 대한 여러 방법에 대해 접근하여 연구 방법들을 모색할 수 있다. 이러한 연구 경향에 맞춰 본 논문에서는 SRM 구동용 컨버터인 C- dump 형태의 컨버터를 BLDC 전동기의 구동 드라이버로 적용하여 이에 대한 특성과 가능성에 관해 연구하였다.

• 설비공학논문집
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• 제15권9호
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• pp.738-743
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• 2003

In the present study, the heating and cooling characteristics of system air-conditioner using a PWM compressor or a BLDC inverter compressor are investigated by the psychometric calorimeter using air enthalpy method. Cooling and heating capacities, power inputs and COPs are measured at the low, moderate, high loads under the cooling and heating standard conditions. At cooling conditions, the capacity of the PWM system is larger than that of the inverter case. Due to large power input, however, low COPs are measured under total load ranges. At heating conditions, the capacity of the PWM method is a little larger than that of the inverter case, except high load range. Since power input is low, large COPs are measured at moderate and high load ranges, which are different from cooling data. This shows that the PW system compared with the inverter case has good energy consumption efficiency at moderate and high load ranges except low load range. And when the system A/C is operated under the cooling and heating standard conditions, COPs are nearly uniform at total load ranges.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.598-600
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• 2008

On this paper, digitally controlled flyback dc-dc converter and dc-ac inverter for bldc motor control are presented, which is used one processor. This system has 12V battery input for the flyback-converter, and the flyback-converter generates 30V output for BLDC motor inverter input. In order to compensate the flyback-converter, the transfer function of flyback converter is derived and digital PI compensator is adapted. Through bode diagram, stability of digital flyback-converter is analyzed. To verify the proposed system, digital simulation of the bldc motor drive using digital flyback-converter are performed.