• Journal of Institute of Control, Robotics and Systems
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• v.8 no.1
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• pp.46-53
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• 2002

The brake system of a high speed train has a crucial role for the safety of the train. To develop a safe brake system of the high speed train, it is necessary to understand the braking principle and phenomena of the total brake system and its subsystems. In this paper, we have suggested a mathematical model which includes car dynamics, interactions between cars, adhesive forces, brake blending algorithm, and the dynamics of each brake devices. Also, we have proposed a ready-time compensation algorithm of eddy-current brake system and a brake control logic on electric-pneumatic blending. A simulation study has shown the proposed models and algorithms are effective on the braking of the train.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.43 no.7
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• pp.1112-1120
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• 1994

This paper presents a servo control scheme for the surface-mounted permanent-magnet synchronous motor(SPMSM) which essentially uses vector control algorithm. The control system is composed of the PI controller for speed control and the current controller using space voltage vector PWM technique. The high-speed calculation and processing for vector control is carried out by TMS320C31 digital signal processor and IGBT module. The proposed scheme is verified through digital simulations and experiments for 2.2kW SPMSM and shows good dynamic performance.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.2
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• pp.130-137
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• 1988

The technique of dual-input describing function's synthesis is introduced and the construction of a nonlinear compensator, based on this technique, is proposed. A nonlinear compensator, describing a complex DIDF depending upon amplitude of the second sinusoidal input signal only, is also proposed, where the second sinusoidal input signal is supplied to the nonlinear compensator by external generator. This compensator, connected in a closed loop of the PI speed control of DC motor, can improve the speed response in view instability limit cycle, low speed response and disturbance of the dynamic shift of the Nyquist's critical point -1 + j O. It is verified theoretically that the improvement of speed response of DC motor using the proposed compensator is achieved by means of the dynamic shift of the Nyquist's critical point on the complex plane, and the speed characterstics of DC motor is to be tested through experiment for its performance.

• Journal of Wind Energy
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• v.13 no.1
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• pp.15-20
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• 2022

In this paper, a power control algorithm for a 30 kW horizontal-axis lift-type stall control wind turbine was developed. The control algorithm consists of three different control strategies for three different control regions. At a wind speed that is much lower than the rated wind speed, it uses a generator speed, generator torque lookup table to track the maximum power coefficient of the rotor. At a wind speed that is higher than the rated wind speed, multiple closed control loops are used to track the rated power. Also, a closed-loop control between the two control regions is used to maintain the rated speed of the rotor. The proposed control algorithm was validated by dynamic simulations using Bladed. Based on the simulation results, it was found that the proposed algorithm works properly in three control regions of the wind turbine. The proposed control algorithm is expected to increase the capacity factor of stall-regulated small wind turbines.

• Proceedings of the KIEE Conference
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• 1989.11a
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• pp.430-433
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• 1989

This paper describes dynamic engine model that is appricable to idle speed control system development. A basic linear engine model responds to throttle and load torque Inputs to provide manifold pressure and speed outputs. Transfer functions are then derived for the modified linear engine model and significant dynamic characteristics are discussed. Lastly, the strategy for controlling idle speed uses the linear optimal control theory. The linear optimal regulator was designed using a state variable and the performance Index was minimized.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.4
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• pp.403-410
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• 1999

In this study, a parallel algorithm has been developed that can quickly solve the optiaml control problem of large-scale dynamic systems. The algorithm adopts the sequential quadratic programming methods and achieves domain decomposition-type parallelism in computing sensitivities for search direction computation. A silicon wafer thermal process problem has been solved using the algorithm, and a parallel efficiency of 45% has been achieved with 16 processors. Practical methods have also been investigated in this study as a way to further speed up the computation time.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.7
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• pp.148-157
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• 1995

This study deals with controlling the speed of Hydrostatic Transmission (HST) system throuth the control of pumping stroke of positive displacement pump using high-speed solenoid valve controlled by digital closed loop PWM method. The method which was done in this study is as follows: First, we modified original positive displacement pump and designed pumping stroke control system of HST by using the high-speed solenoid valve. Second, after experimenting static and dynamic characteristics on each signal flow, we identified system parameter of approximated model. Finally, to control the speed of HST, we controlled the angle of the swash plate of positive displacement pump by controlling the pressure in the control cylinder chamber. Test which was carried out in the laboratory shows that transient and steady state response could be improved by PID controller.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.856-859
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• 2003

The switched reluctance motor(SRM) drive system provides a good adjustable speed and torque characteristics. However, because of the torque production mechanism, it also has some disadvantage such as higher torque ripple and fluctuation in speed. To reduce torque ripple and to control speed precisely, digital signal processor(BSP) is adopted. The DSP TMS320F241 was used to be realized this drive system. Test results show that the suggested control system has the ability of dynamic and precise speed control.

• Journal of Wind Energy
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• v.2 no.1
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• pp.82-89
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• 2011

his dissertation is on power control system for MW-class wind turbine. Especially, the control purpose is reduction in electrical power and rotor speed. The base control structure is power curve tracking control using variable speed variable pitch operational type. For the reduction of fluctuations, more control algorithm is needed in above rated wind conditions. Because general pitch control system is low dynamic response as compared with the wind speed change. So, this paper introduces about the pitch feed forward control to minimize fluctuations of the electrical power and rotor speed. To maintain rated electrical power, the algorithm of feed forward control adds feed forward pitch amount to the pitch command of power curve tracking control. The effectiveness of the feed forward control is verified through the simulation.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.138-138
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• 2000

In this paper, a methodology for designing a controller based on inverse dynamics for speed control of DC motors is presented. The proposed controller consists of a prefilter, the inverse dynamic model of a system and a fuzzy logic controller. The prefilter prevents high frequency effects from the inverse dynamic model. The model of the system is characterized by a nonlinear equation with coulomb friction. The fuzzy logic controller regulates the error between the set-point and the system output which may be caused by disturbances and it simultaneously traces the change o( the reference input. The parameters of the model are estimated by a genetic a]gorithm. An experimental work on a DC motor system is carried out to illustrate the performance of the proposed controller