• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1998년도 전력전자학술대회 논문집
• /
• pp.197-199
• /
• 1998

A neuro-fuzzy based torque profile model of SRM with considerably improved accuracy is obtained using the measured data for training. The inferred torque profiles, which comprise magnetic non-linearities, represent the dynamic model of SRM. Then the reference torque signal with optimized waveform and switching angle are decided to control the torque directly. Hence, the presented scheme controls the torque in an instantaneous basis, allowing powerful torque control with minimum torque ripple even during the transient operation of the motor. Simulation and experimental results demonstrating the effectiveness of the proposed torque control scheme are presented.

• 전자공학회논문지S
• /
• 제36S권11호
• /
• pp.128-139
• /
• 1999

본 논문은 6-스텝까지 인버터의 선형제어영역을 넓히기 위한 공간전압 변조방법의 선형화 기법에 대해 제안하였다. 이 방법은 인버터에서 발생시키고자 하는 전압을 연속모드에서는 보상각을 얻기 위해서 6스텝 모드를 포함하는 불연속모드에서는 불연속 스위칭이 이루어지도록 하는 유지각을 얻기 위해서 퓨리에 급수를 이용하고 있다. 이 각들의 근사화 수식들을 과변조 영역에서 기본파 전압을 보상하기 위해 사용하였다. 따라서, PWM 인버터 출력전압의 최대 활용과 선형 제어를 이룰 수 있다.

• 전력전자학회논문지
• /
• 제7권3호
• /
• pp.253-261
• /
• 2002

본 논문에서는 TMS320F240 DSP를 통해 제어되는 디지털 히스테리시스 제어기를 사용한 Switched Reluctance Motor(SRM)의 위치제어시스템을 제안하였다. SRM은 구조가 간단하고 효율이 놀지만 전동기 구동 특성상 전력용 반도체 소자를 이용한 구동 시스템이 필수적이기 때문에 일반 전동기 제어시스템에 비해 전체 시스템의 제작비용이 증가하게 된다. 이러한 단점을 극복하고 SRM의 활용성을 높이기 위해서는 제어용 드라이브가 필수적으로 요구되는 서보시스템으로서와 SRM 제어시스템을 개발하는 것이다. 따라서 본 연구에서는 시스템 개발과 구현에 있어 아날로그 히스테리시스 제어기를 사용할 경우 하드웨어적인 방법에 의한 파라메타 수정 및 제작의 문제점을 해결하고 전체적인 시스템의 개발단가를 낮추기 위해 DSP내에서의 연산을 통해 제어되는 디지털 히스테리시스 제어기를 설계하여 SRM의 위치제어 시스템을 구현하였으며, 실헐을 통해 제어 및 응답특성을 고찰함으초써 서보 구동 시스템으로서의 SRM의 이용 가능성을 확인하였다.

• 제어로봇시스템학회논문지
• /
• 제19권6호
• /
• pp.495-500
• /
• 2013

This paper proposes a double sliding surfaces based on a sliding mode control for a tracking control of nonholonomic mobile robots in the Cartesian coordinates. In order to remove sliding surface constraints, we design the additional sliding surface for the heading angle with respect to the newly defined coordinates. Then, we define the switching law based on the posture error to combine the designed sliding surface with the previous one. By using the double sliding surfaces and the switching law, we obtain the control law for arbitrary trajectories. It is proved that the position tracking error and the heading direction error asymptotically converge to zero, respectively, with the Lyapunov stability theory. Finally, through computer simulations, we demonstrate the effectiveness of the proposed control system.

• 한국조명전기설비학회지:조명전기설비
• /
• 제9권5호
• /
• pp.41-50
• /
• 1995

Single-phase induction motors are widely used in many light duty applications, especially in home and office. many applications which use these motors require adjustable speed control continuously. In general, the speed control of single-phase induction motor is accomplished at a few discrete speeds by using tapped-windings, pole switching or gear. These techniques are inefficient and complicated. In this paper, Torque controller which adjusts a generating torque using phase difference between main winding voltage and auxiliary winding voltage is proposed. The analysis includes the determination of the relationship between the auxiliary winding voltage is proposed. The analysis includes the determination of the relationship between the auxiliary winding voltage phase angle and torque. Simulation results of the torque-speed characteristics using the controlled auxiliary winding supply are shown and discussed. and the drive is tested experimentally to verify the results of the theory by using a dynamometer.

• 한국조명전기설비학회지:조명전기설비
• /
• 제8권2호
• /
• pp.69-76
• /
• 1994

An effective method for reducing the harmonics in double connected modified current source inverter[MCSI] by switching taps on auto transformer is presented in this paper. The proposed system operates as like a 24 step MCSI by adding only tap changing auxiliary circuit which consists of several taps and static switching elements to the 12 step multiple inverter, which is double connected three-phase six-step MCSI with an auto transformer. The basic theories of the proposed inverter systems for analyzing the output waveforms are described. And to optimize the effectiveness of the harmonic reduction, the optimum turn ratio and the tap changing control angle of auto transformer are decided by digital simulation and its validity is verified by experiment. Although the construction of the proposed inverter is very simple, it is clarified that the output waveform of the inverter is almost the same as that of the conventional 24 step multiple inverter under the optimum condition.

• 제어로봇시스템학회논문지
• /
• 제19권1호
• /
• pp.1-9
• /
• 2013

This paper presents a new control algorithm for dynamic control of a unicycle robot. The unicycle robot motion consists of a pitch that is controlled by an in-wheel motor and a roll that is controlled by a reaction wheel pendulum. The unicycle robot doesn't have any actuator for a yaw axis control, which makes the derivation of the dynamics relatively simple. The Euler-Lagrange equation is applied to derive the dynamic equations of the unicycle robot to implement the dynamic speed control of the unicycle robot. To achieve the real time speed control of the unicycle robot, the sliding mode control and LQ regulator are utilized to guarantee the stability while maintaining the desired speed tracking performance. In the roll controller, the sigmoid-function based sliding mode controller has been adopted to minimize the chattering by the switching function. The LQR controller has been implemented for the pitch control to drive the unicycle robot to follow the desired velocity trajectory in real time using the state variables of pitch angle, angular velocity, angle and angular velocity of the wheel. The control performance of the two control systems form a single dynamic model has been demonstrated by the real experiments.

• 전기전자학회논문지
• /
• 제2권2호
• /
• pp.166-172
• /
• 1998

스위치드 리럭턴스 전동기는 구조가 간단하고 회전자관성이 작으며 고효율을 가지는 전동기이다. 그러나 회전자 위치각에 적절한 상여자 신호를 동기화하기 위해서는 위치센서가 필수적이다. 이 위치센서로 인하여 구동시스템의 가격상승과 열악한 환경에서 시스템의 신뢰성이 저하되는 문제점을 가지게 된다. 본 논문에서는 위치 및 속도센서가 없는 스위치드 리럭턴스 전동기의 속도제어 시스템을 연구하였다. 센서리스 SRM의 안정된 속도제어를 위하여 회전자 위치검출을 상전류 및 변화율 검출로부터 구하였으며 속도오차에 대하여 도통각 주기폭을 변동하는 속도제어 시스템을 제안하였다. 이 구동시스템은 위치결정회로 속도제어기, 디지탈논리 정류자, 스위칭각 제어기와 인버터로 구성된다. 제안된 시스템은 실험을 통하여 성능을 검증하였다.

• Journal of Electrical Engineering and Technology
• /
• 제13권4호
• /
• pp.1528-1538
• /
• 2018

In this paper, configuration of $1-{\phi}$ seven-level boost DC-link cascade based reversing voltage multilevel inverter (BDCLCRV MLI) is proposed for uninterrupted power supply (UPS) applications. It consists of three level boost converter, level generation unit and full bridge circuit for polarity generation. When compared with conventional boost cascaded H-bridge MLI configurations, the proposed system results in reduction of DC sources, reduced power switches and gate drive requirements. Inverter switching is accomplished by providing appropriate switching angles that is generated by any optimization switching angle techniques. Here, round modulation control (RMC) method is taken as the optimization method and switching angles are derived and the same is compared with various switching angles methods i.e., equal-phase (EP) method, and half-equal-phase (HEP) method which results in improved quality of obtained AC power with lowest total harmonic distortion (THD). Reduction in DC sources and switch count makes the system more cost effective. A simulation and prototype model of $1-{\phi}$ seven-level BDCLCRV MLI system is developed and its performance is analyzed for various operating conditions.

• 제어로봇시스템학회논문지
• /
• 제15권3호
• /
• pp.293-299
• /
• 2009

This paper discusses an autonomous navigation system for urban environments. For the localization of the robot, EKF (Extended Kalman Filter) algorithm is used with odometry, angle sensor, and DGPS (Differential Global Positioning System) measurement. Especially in an urban environment, DGPS is often blocked by buildings and trees and the resulting inaccurate positioning prevents the robot from safe and reliable navigation. In addition to the global information from DGPS, the local information of the curb on the roadway is used to track a route when the global DGPS information is inaccurate. For this purpose, curb detection algorithm is developed and implemented in the developed navigation algorithm. Four different types of navigation strategies are developed and they are switched to adapt to different localization conditions according to the availability of DGPS and the existence of the curbs on the roadway. The experimental results show that the designed switching strategy improves the navigation performance adapting to the environment conditions.