• The Transactions of the Korean Institute of Power Electronics
• /
• v.6 no.1
• /
• pp.49-56
• /
• 2001

This paper presents a new approach to the problem based on neural network methods. Instead of using general controllers, neural networks PID control are used to control AC servo motor. The most popular and widely used control method in servo system control loops is PID type. PID controller has the features of simple structure, stability and reliability. But it has limitations in complex system control and can not remain above virtues under the conditions of parameters uncertain and environment uncertainties. AC servo motor controller is designed for drive of the cartesian coordinate type for machine tools.

• Proceedings of the KIPE Conference
• /
• 1999.07a
• /
• pp.443-447
• /
• 1999

The AC drive systems of a voltage source inverter and an induction motor. The inverter non linearity caused by the turn on/off time dependency of the current level in the switching IGBT is described in the first part of this paper. To improve the low-speed drive characteristics, accurate applied voltage calculation is proposed under considerations of the compensations for the quantization error in the digital controller, the forward voltage drop of switching drives and the dead time of the inverter. The experimental studies show the improved drive characteristics.

• Proceedings of the KIPE Conference
• /
• 2016.07a
• /
• pp.117-118
• /
• 2016

본 논문에서는 AC 및 DC 전원을 동시에, 또는 선택적으로 사용하여 구동할 수 있는 단상 영구자석 전동기 구동 시스템을 제안한다. 제안된 회로는 일반적인 Full-bridge회로와 유사하게 4개의 전력 소자로 구성되어 경제적인 회로 구성으로 두 가지 전원을 사용할 수 있다. 또한, DC전원측으로의 전력흐름도 가능하여, DC전원으로 배터리를 사용할 경우 충전회로의 삭제도 가능하다. 제안된 회로의 동작을 모의실험을 통하여 검증하였다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.8
• /
• pp.1685-1691
• /
• 2004

The objective of this study is aimed at reducing the contour error of AC Servo derives by improving the interpolation error of each axis through variable structure control system. The errors in machining process by AC Servo motor are due to many elements, such as the delay of the servo drivers, friction and the gain mismatch between x axis and y axis motors and so on. Sliding mode control system is applied to a AC servo drive as a numerical example in this paper. The experiment results which are compared with those of typical PI scheme show the validity of improvement in circular interpolation error of the system.

• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.478-480
• /
• 2008

On this paper, digitally controlled push-pull dc-dc converter and dc-ac inverter for induction motor control are presented, which is used one DSP(digital signal processor). This system has 12V battery input for the push-pull converter, and the push-pull converter generates 300V output for induction motor inverter input. In order to compensate the push-pull converter, the transfer function of push-pull converter is derived and digital PI compensator is adapted. Through bode diagram, stability of digital controlled push-pull converter is analyzed. To verify the proposed system, digital simulation of the induction motor drive using digital push-pull converter are performed.

• Proceedings of the KIPE Conference
• /
• 2008.06a
• /
• pp.598-600
• /
• 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.

• Journal of Advanced Marine Engineering and Technology
• /
• v.11 no.2
• /
• pp.37-50
• /
• 1987

In an effort to conserve electric power, variable voltage variable frequency pulse width modulated (PWM) inverters are being applied increasingly to the variable speed control of the induction motors. The use of the PWM technique in motor drive applications is considered advantageous in many ways. For industrial applications, the PWM drive obtains its DC input through simple uncontrolled rectification of the commercial AC line and is favored for its good power factor, good efficiency, its relative freedom regulation problem, and mainly for its ability to operate the motor with nearly sinusoidal current waveforms. The purpose of this paper is to design a three phase natural sampled PWM inverter using microprocessor with simple control algorithm and hybrid control circuit has been built to implement this PWM scheme. In this system, the microprocessor can be used only for calculations directly related to motor control tasks by the design of hybrid circuit which sends PWM signals to the motor.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.5B no.4
• /
• pp.358-365
• /
• 2005

In induction machine drive without a speed sensor, the estimation of the motor flux and speed often becomes deteriorated at low speeds with low back EMF. Our analysis shows that, in addition to the state resistance variation, the estimated value of field orientation angle is often corrupted by accumulative errors from the integration of voltage variables at motor terminals that have low signal/noise ratio at low frequencies. A repetitive loop path of integration in the feedback can amplify this type of error, thus speeding up the degradation process. The control system runs into information starvation due to the loss of correct field orientation. The machine's spiral vectors are controlled only in a reduced dimension in this situation. A novel control scheme is developed to improve the control performance of motor's current, torque and speed at low frequencies. The scheme gains a full-dimensional vector control and is less sensitive to the combined effect of the error sources at the low frequencies. Experimental tests demonstrate promising performances are achievable even below 0.5 Hz.

• Journal of Power Electronics
• /
• v.14 no.5
• /
• pp.989-999
• /
• 2014

High-performance Current Source Inverter (CSI)-fed, variable speed alternating current drives are prepared for various industrial applications. CSI-fed Induction Motor (IM) drives are managed by using different control methods. Noteworthy methods include scalar Control (V/f), Input-Output Linearization (IOL) control, Field-Oriented Control (FOC), and Direct Torque Control (DTC). The objective of this work is to compare the dynamic performance of the aforementioned drive control methods for CSI-fed IM drives. The dynamic performance results of the proposed drives are individually analyzed through sensitivity tests. The tests selected for the comparison are step changes in the reference speed and torque of the motor drive. The operation and performance of different vector control methods are verified through simulations with MATLAB/Simulink and experimental results.

• Journal of Power Electronics
• /
• v.10 no.3
• /
• pp.285-292
• /
• 2010

This paper presents a current mode integrated control technique (CM-ICT) using a modified voltage space vector modulation (MSVM) for Z-source inverter (ZSI) fed induction motor drives. MSVM provides a better DC voltage boost in the dc-link, a wide range of AC output voltage controllability and a better line harmonic profile. In a voltage mode ICT (VM-ICT), the outer voltage feedback loop alone is designed and it enforces the desired line voltage to the motor drive. An integrated control technique (ICT), with an inner current feedback loop is proposed in this paper for the purpose of line current limiting and soft operation of the drive. The current command generated by the PI controller and limiter in the outer voltage feedback loop, is compared with the actual line current, and the error is processed through the PI controller and a limiter. This limiter ensures that, the voltage control signal to the Z-source inverter is constrained to a safe level. The rise and fall of the control signal voltage are made to be gradual, so as to protect the induction motor drive and the Z-source inverter from transients. The single stage controller arrangement of the proposed CM-ICT offers easier compensation. Analysis, Matlab/Simulink simulations, and experimental results have been presented to validate the proposed technique.