• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제49권1호
• /
• pp.70-76
• /
• 2000

This paper describes a one-chip micom controller and phase angle control method for self-starting and energy saving of single-phase induction motor. The proposed method is based on the optimal efficiency control which is running by variable phase angle of main winding current such as to maintain the maximum efficiency characteristics of the motor, in voltage control with TRIAC. Experiments are focused on a capacitor starting single-phase induction motor. The optimal energy saving by variable phase angle control are verified by experimental results. Also, auxiliary winding was controlled by electronic starting switch.

• 조명전기설비학회논문지
• /
• 제28권12호
• /
• pp.95-102
• /
• 2014

This paper proposes a coordinated control for an independent multi-phase transverse flux linear synchronous motor (IM-TFLSM) based on magnetic levitation. The stator structures of the IM-TFLSM are composed of a two set, which has independent three-phase windings and a double-sided air-gap as opposed to the conventional Y-connected three-phase linear motors. A suitable control algorithm is necessary to operate the applied linear machine. This study proposes a coordinated control algorithm for adjusting the mover air-gap and thrust force of the IM-TFLSM in order to maintain air-gap and phase shifted current control of the independent 3-phase modules. In addition, the principle of operation and its special structures are described in detail and the validity and effectiveness of the control algorithm is verified through multiple experimental results.

• 조명전기설비학회논문지
• /
• 제26권6호
• /
• pp.73-80
• /
• 2012

Generally, the phase control dimmer has been widely used due to simple interface and easy handling. However, the electrical characteristics are not good for the method in which the phase control dimmer cuts the input voltage. This paper has researched about DALI(Digital Addressable Lighting Interface) controller, that is the digital lighting control method, and implemented DALI protocol satisfied with the IEC-62386 standard. In addition, the existing phase control dimmer was used as the controller of DALI and not only individual control but also group control was possible. And the performance was proved to be good by applying our theory to 30[W] LED lighting control system.

• 한국정밀공학회지
• /
• 제23권8호
• /
• pp.64-71
• /
• 2006

In this paper, a uniform speed controller for an ultrasonic rotary motor is developed using the phase-difference method. The phase difference method uses traveling waves to drive the ultrasonic motor. The traveling waves are obtained by adding two standing waves that have a different phase to each other. A compact phase-difference driver system is designed and integrated by combining VCO(Voltage Controlled Oscillator) and phase shifter. Theoretically the relationship between the phase difference in time and the rotational speed of the ultrasonic motor is sine function, which is verified by experiments. Then a series of experiments under various loading conditions are conducted to characterize the motor's performance that is the relationship between the speed and torque. Proportional-integral control is adopted for the uniform speed control. The proportional control unit calculates the compensating phase-difference using the rotating speed which is measured by an encoder and fed back. Integral control is used to eliminate steady-state errors. Differential control for reducing overshoot is not used since the response of ultrasonic motor is prompt due to its low inertia and friction-driving characteristics. The developed controller demonstrates reasonable performance overcoming disturbing torque and the changes in material properties due to continuous usage.

• Journal of Electrical Engineering and Technology
• /
• 제9권3호
• /
• pp.899-907
• /
• 2014

This paper deals with fault-tolerant control of five-phase induction motor (IM) drives under single-phase open. By exploiting a decoupled model for five-phase IM under fault, the indirect field-oriented control ensures that electromagnetic torque oscillations are reduced by particular magnitude ratio currents. The control techniques are developed by the third harmonic current injection, in order to improve electromagnetic torque density. Furthermore, Proportional Resonant (PR) regulator is adopted to realize excellent current tracking performance in the phase frame, compared with Proportional Integral (PI) and hysteresis regulators. The analysis and experimental results confirm the validity of fault-tolerant control under single-phase open.

• 드라이브 ㆍ 컨트롤
• /
• 제15권4호
• /
• pp.1-10
• /
• 2018

Spool displacement of a direction control valve is the standard signal to measure the bandwidth frequency of the direction control valve. When the spool displacement signal is not available, it is suggested in this study to use the metering hydraulic line as an alternative way to measure - 90 degree phase bandwidth frequency of the hydraulic direction control valve. Dynamics of the hydraulic line is composed of inertia, capacitance, and friction effects. The effect of oil inertia is dominant in common hydraulic line dynamics and the line dynamics is close to a derivative action in a range of high frequency; such as a range of bandwidth frequency of common directional control valves. Phase difference between spool displacement and line load pressure is nearly constant as a valve close to 90 degree. If phase difference is compensated from the phase between valve input and pressure, compensated phase may be almost same as the phase of spool displacement that is a standard signal to measure phase bandwidth frequency of the directional control valve. A series of experiments were conducted to examine the possibility of using line pressure in to measure phase bandwidth frequency of a directional control valve. Phase bandwidth frequency could be measured with relatively high precision based on metering hydraulic line technique and it reveals consistent results even when valve input, oil temperature, and supply pressure change.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1997년도 춘계학술대회 논문집
• /
• pp.41-45
• /
• 1997

To design a control system, it is a elementary point that the stability of the system should be guaranteed. Also, the phase of the system plays an important role for its frequence performance. In this paper, we present two stability criterion of repetitive control system with phase-lead and lag compensator. First, the stability criterion for the servo control system with phase-lead and lag compensator is shown by using small-gain theorem. Second, for the repetitive control system with the compensator, the stability criterion, also, is determined by using small-gain theorem. Two stability criterions show the same results that the stability depends on a coefficient of the phase-lead and lag compensator under some condition in servo control system and repetitive control system.

• Journal of Electrical Engineering and Technology
• /
• 제13권6호
• /
• pp.2354-2363
• /
• 2018

This paper proposed a novel double closed control strategy for single-phase voltage source pulse width modulation (PWM) rectifier based on active disturbance rejection control (ADRC) and dq current decoupling control. First, the mathematical model of the single-phase PWM rectifier in the d-q axis synchronous rotating reference frame is established by constructing a virtual component using a second-order generalized integrator (SOGI). Then, the mathematical model is simplified according to the active power conservation, and the first-order equation of single-phase PWM rectifier voltage outer loop is acquired. A linear auto-disturbance rejection controller is used to design the voltage outer loop according to the first-order equation. Finally, the proposed control strategy and the traditional PI control are compared and verified by simulation and physical experiments. Both simulation and experimental results confirm that the proposed control strategy has excellent dynamic performance and strong rejection ability to disturbances.

• 한국정밀공학회지
• /
• 제14권4호
• /
• pp.88-96
• /
• 1997

This paper suggests a new non-linear friction compensation for digital control systems. This control adopts a hysteresis nonlinear element which can introduce the phase lead of the control system to compensate the phase delay comes from the inherent time delay of a digital control. A proper Lyapunov function is selected and the Lyapunov direct method is used to prove the asymptotic stability of the suggested control.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 추계학술대회 논문집
• /
• pp.987-993
• /
• 1996

This report suggests a new non-linear friction compensation for digital control systems. This control adopts a hysteric nonlinear clement which can introduce the phase lead of the control system to compensate the phase delay comes from the inherent time delay of a digital control. The Lyapunov direct method is used to prove the asymtotic stability of the suggested control, and the stability and the effectiveness are verified analytically and experimentally on a single axis servo driving system.