Novel Loss Reduction Pulsewidth Modulation Technique for Brushless dc Motor Drives Fed by MOSFET Inverter

-This paper proposes a capacitance estimation method of the dc-link capacitor for brushless DC motor (BLDCM) drive systems. In order to estimate the dc-link capacitance, the BLDCM is operated in quadrant-II or -IV among four-quadrant operation. Quadrant-II and -IV are called reverse braking and forward braking, respectively. During the braking operation of the BLDCM, the capacitor is charged by the phase current and then the voltage is increased during the braking operation time. The capacitor current and voltage can be obtained by using the phase current sensor of BLDCM and the dc-link voltage sensor. The capacitance and be easily obtained by the voltage equation of the capacitor. The proposed method guarantees the reliable and simple calculation of the dc-link capacitance without additional hardware system except several the sensors already installed for the motor control system. The effectiveness of the proposed method is verified through both the simulation and experimental results.

Section: Fig 7 Block Diagram Of the Proposed Capacitance Estimationmentioning

confidence: 99%

Capacitance Estimation Method of DC-Link Capacitors for BLDC Motor Drive Systems

Moon¹,

Kim²,

Park³

et al. 2016

“…With this consideration, PWM techniques are very important in the controller design for a low noise operation and running at higher speeds [1]. Because of only two out of three phases are excited at any instant time, the BLDC motor can be driven with different PWM configurations [20]. PWM signals could be only applied on the high side switch and the low side is active during the step, PWM applied on the low side switch and high side enabled during the step, or PWM applied on both sides and switched on / off together [21,22].…”

Section: Pwm Motor Drivingmentioning

confidence: 99%

Sensorless Detection of Position and Speed in Brushless DC Motors using the Derivative of Terminal Phase Voltages Technique with a Simple and Versatile Motor Driver Implementation

Gamazo-Real¹,

Gil²

2015

-The detection of position and speed in BLDC motors without using position sensors has meant many efforts for the last decades. The aim of this paper is to develop a sensorless technique for detecting the position and speed of BLDC motors, and to overcome the drawbacks of position sensorbased methods by improving the performance of traditional approaches oriented to motor phase voltage sensing. The position and speed information is obtained by computing the derivative of the terminal phase voltages regarding to a virtual neutral point. For starting-up the motor and implementing the algorithms of the detection technique, a FPGA board with a real-time processor is used. Also, a versatile hardware has been developed for driving BLDC motors through pulse width modulation (PWM) signals. Delta and wye winding motors have been considered for evaluating the performance of the designed hardware and software, and tests with and without load are performed. Experimental results for validating the detection technique were attained in the range 5-1500 rpm and 5-150 rpm under no-load and full-load conditions, respectively. Specifically, speed and position square errors lower than 3 rpm and between 10º-30º were obtained without load. In addition, the speed and position errors after full-load tests were around 1 rpm and between 10º-15º, respectively. These results provide the evidence that the developed technique allows to detect the position and speed of BLDC motors with low accuracy errors at starting-up and over a wide speed range, and reduce the influence of noise in position sensing, which suggest that it can be satisfactorily used as a reliable alternative to position sensors in precision applications.

“…Based on traditional PWM schemes [12,13,14] in threephase BLDC motor drives under the operation mode of 120 degree conduction, two similar PWM schemes for high switches in PWM mode and low switches in turning-on mode (HpwmLon) and high switches in turning-on mode and low ones in PWM mode (HonLpwm) are developed for two-phase BLDC motor drives in the mode of 180 degree conduction.…”

Section: Pwm Scheme For Two-phase Bldc Drivementioning

confidence: 99%

New PWM Technique for Two-Phase Brushless DC Motor Drives

Lin¹,

Kwon²

2013

-A new PWM technique for a two-phase BLDC motor fed by a two-phase eight-switch inverter is proposed in this paper. It is well known that a two-phase eight-switch inverter can significantly improve power output compared with a two-phase six-switch inverter in a two-phase motor drive. To drive the two-phase BLDC motor simply and effectively, two normal PWM strategies are investigated to manage speed regulation. However, under the conditions of low speed and light load, especially during the braking process, the current in a short time of one period is near zero, which is a discontinuous waveform every half period. To solve it, a novel PWM technique is investigated to improve the operational performance of normal technique. Using the new PWM scheme, the current continues every half period and the braking performance is improved. The effectiveness of the proposed PWM method is verified through the experiments.