• Proceedings of the KIPE Conference
• /
• 2002.07a
• /
• pp.355-359
• /
• 2002

Much attention has been given to EMI effects created in variable speed ac drive system. Zero switching states of inverter control invoke large common mode voltage. This paper focuses on the switching techniques to mitigate common mode voltage. This paper proposes a common-mode voltage reduction method based on sinusoidal pulse width modulation in three phase PWM inverter system. By using three carriers wave displaced by 120 degrees, it is possible to eliminate a common mode voltage pulse In one control period. Simulation and experimental results show that common mode voltages In the proposed technique are reduced more than conventional technique.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.18 no.7
• /
• pp.587-595
• /
• 2006

A system operating algorithm was developed for the effective operation of a multi-type air-conditioning system. The system operating algorithm includes control algorithms for a safety mode, an initial operating mode, a stabilization mode, a fault diagnosis mode, an efficiency mode, and a tracking mode. Various tests were performed to show the effectiveness of these algorithms. Tests showed good results for the operation of a multi-type air-conditioning system. Therefore, these algorithms developed for this study may be used for the effective control of a multi-type air-conditioning system.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.9
• /
• pp.1750-1756
• /
• 2009

In this paper, 5 kWh class Superconductor Flywheel Energy Storage System (SFES) was constructed including motor/generator, superconductor magnetic bearing(SMB), composite rotor and electromagnetic damper(EMD) system. High speed rotation test was performed after levitating flywheel rotor only using EMD without SMB. the PD controller of EMD was designed. the control system is constructed using xPC which is real time digital control system. the results of high speed rotation test showed that proposed EMD system have sufficient damping in cylindrical mode and conical mode, and vibration of wheel was suppressed below 10 ${\mu}m$.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.16 no.2
• /
• pp.71-80
• /
• 2002

According to the rapid growth of high speed and precise industry, the application of synchronous motor has been increased. In the application fields, these fast dynamic response is of prime importance. In particular, since the PMLSM(Permanent Magnet Linear Synchronous Motor) has characteristics of high speed, high thrust, it has been used in high-performance servo drive. From these reasons, it is recently used for high precise position control, and machine tool. In this paper, a study of the sliding mode with VSS (Variable Structure System) design for a PMLSM is presented. For fast and precise motion control of PMLSM, the compensation of disturbance and parameter variation is necessary. Hence we eliminate the reaching phase use of VSS that is changed to switching function and vector control using the state observer. And we proposed to sliding mode control algorithm so that realize fast response without overshoot, disturbance and parameter variation.

• Journal of Power Electronics
• /
• v.18 no.4
• /
• pp.1075-1085
• /
• 2018

To deal with the operation performance degradation of permanent magnet synchronous machine (PMSM) drives with uncertainties and unmodeled dynamics, this paper presents a finite-time nonlinear disturbance observer (FTNDO) based discretized integral sliding mode (DISM) composite control scheme. Based on the reaching-law approach, a DISM speed controller featuring a superior dynamic quality and global robustness against disturbances is constructed. This controller can avoid the reaching phase and overlarge control action. In addition, a sliding mode differentiator based FTNDO is devised and extended to the discrete-time domain for disturbance estimation. The attractive features of the FTNDO are that it can provide a finite-time converging estimation and alleviate the chattering effect in conventional sliding mode observers, while retaining robustness to parameter variations. By feeding the estimate forward to the pre-stage DISM controller, both disturbances and chattering can be significantly suppressed. Moreover, considering the estimation error of a FTNDO caused by discrete sampling, a stability analysis of the composite controller is discussed. Experimental results validate the superiority of the presented scheme.

• International Journal of Automotive Technology
• /
• v.7 no.6
• /
• pp.729-739
• /
• 2006

This paper describes an active fault-tolerant control system for an induction motor drive that propels an Electrical Vehicle(EV) or a Hybrid one(HEV). The proposed system adaptively reorganizes itself in the event of sensor loss or sensor recovery to sustain the best control performance given the complement of remaining sensors. Moreover, the developed system takes into account the controller transition smoothness in terms of speed and torque transients. In this paper which is the sequel of (Diallo et al., 2004), we propose to introduce more advanced and intelligent control techniques to improve the global performance of the fault-tolerant drive for automotive applications(e.g. EVs or HEVs). In fact, two control techniques are chosen to illustrate the consistency of the proposed approach: sliding mode for encoder-based control; and fuzzy logics for sensorless control. Moreover, the system control reorganization is now managed by a fuzzy decision system to improve the transitions smoothness. Simulations tests, in terms of speed and torque responses, have been carried out on a 4-kW induction motor drive to evaluate the consistency and the performance of the proposed fault-tolerant control approach.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10b
• /
• pp.852-855
• /
• 1996

A variable structure controller is developed for an AC servo motor used in CNC milling machines. The designed controller is implemented as an outer loop controller to a factory designed motor-servopack system. The robustness parameter is tuned for a fast response when the speed tracking error is large, while it is tuned for small oscillations when the speed tracking error is small. The designed controller is installed on a CNC machine using a PC. Cutting experiments show improved performance over the factory-designed controller.

• Transactions of The Korea Fluid Power Systems Society
• /
• v.4 no.2
• /
• pp.21-27
• /
• 2007

This paper deals with the issue of trajectory tracking control of a clamping cylinder for injection moulding machine, which is directly driven by speed controlled hydraulic pump in combination with AC servomotor. As a fundamental step prior to tracking controller design, feedback control system is developed by implementing a position control loop parallel with a system pressure control loop. A sliding mode controller combining velocity feedforward scheme is developed for enhancing the tracking performance. Consequently a significant reduction in tracking error is achieved for both position and pressure control applications.

• Journal of Electrical Engineering and Technology
• /
• v.4 no.4
• /
• pp.499-509
• /
• 2009

Electric vehicles (EV) are developing fast during this decade due to drastic issues on the protection of environment and the shortage of energy sources, so new technologies allow the development of electric vehicles (EV) by means of electric motors associated with static converters. The proposed propulsion system consists of two induction motors (IM) that ensure the drive of the two back driving wheels. The electronic differential system ensures the robust control of the vehicle behavior on the road. It also allows controlling, independently, every driving wheel to turn at different speeds in any curve. This paper presents the study of an hybrid Fuzzy-sliding mode control (SMC) strategy for the electric vehicle driving wheels, stability improvement, in which the fuzzy logic system replace the discontinuous control action of the classical SMC law. Our electric vehicle fuzzy-sliding mode control's simulated in Matlab SIMULINK environment, the results obtained present the efficiency of the proposed control with no overshoot, the rising time is perfected with good disturbances rejections comparing with the classical control law.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.3
• /
• pp.850-860
• /
• 1996

This paper considers a sliding mode controller for a depth and course control of a class of submersible Vehicles. Since the vehicle used here shows complex dynamic characteristics sensitive to speed variation and buoyancy, robustness in control of vertical and horizontal plane motions of the vehicle is achieved by using the sliding mode controller of which a structure varies according to a pre-designed principle, so called the variable structure control. To compare this controller with another in robustness, PID controller for the same model of vehicle is designed. From various simulations for two controllers, it is shown that the sliding mode controller is the more robust anainst to modeling errors and disturbances.