• 제어로봇시스템학회논문지
• /
• 제7권10호
• /
• pp.806-811
• /
• 2001

The analysis and control algorithm of a new type unsymmetrical self-bearing step motor is presented. The motor actuator is used for both motor and bearing functionality without any redundant coil windings or redudant electromagnets for bearing functionality. Self bearing step motor layout and control current generation method for unsymmetrical position of electromagnets are described. This new current generation method without additional current for bearing functionality leads to minimize the power loss. As the result of the unbalance response approach, the constant torque is possible, even though the bearing functionality is added or not.

• 한국군사과학기술학회지
• /
• 제2권2호
• /
• pp.242-250
• /
• 1999

This paper presents an estimation scheme of the external torque applied on the motor by using measured motor input current when the IPM(Interior Permanent Magnet) rotor type BLDC motor operates with constant speed. In general, the BLDC motor is controlled by vector control method. If it could be operated at over critical speed, the control scheme must be modified to flux-weakening control method. The external torque applied on the motor using flux-weakening control method could not be calculated by conventional torque equation because the demagnetizing current Id exists in the motor input current. In this paper, the commonly used flux-weakening control method is studied and the modified torque estimation scheme is suggested. The estimation scheme has been verified by the simulations and experimental results.

• 전력전자학회논문지
• /
• 제21권2호
• /
• pp.144-149
• /
• 2016

This paper presents a power control method of high-speed single-phase BLDC motor. Most electric appliances require a power factor corrector (PFC) to mitigate grid current harmonics. However, the reactive components and power semiconductors in the PFC increase system cost and dimension. In this paper, a new motor drive system for a high-speed single-phase BLDC motor is proposed, which can decrease grid current harmonics without PFC by directly manipulating motor power and eliminating bulky electrolytic dc-link capacitor. Given that the proposed motor power control method does not require motor current controller, no current sensor is necessary. Moreover, the proposed algorithms can be easily implemented using a low-cost micro-controller. The effectiveness of the proposed power control method is verified by experiments.

• 대한전기학회논문지:시스템및제어부문D
• /
• 제54권12호
• /
• pp.705-712
• /
• 2005

This paper deals with speed-sensorless control of an AC servo motor using Fuzzy-Tuning High Gain Observer(FTHGO). Resolver or encoder can be used to measure a rotor speed, but it has a limit to detect motor speed precisely. To solve this problem, it is studied to measure a speed of an AC servo motor without sensor. In this paper, the gain of an observer to estimate motor speed is properly set up and designed using the fuzzy control theory. It calculates the differentiation of the rotor current of the AC motor and estimates the rotor speed using it. Proposed speed sensorless control is performed using the estimated speed as the control variable. Designed FTHGO is applied to AC servo motor to verify the feasibility of the proposed observer. Feasibility of the FTHGO proposed in this paper is proven comparing the experimental results with/without the speed sensor.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.640-643
• /
• 1997

This paper describes speed controller of a induction motor for electric vehicles using PLL and Fuzzy logic. The proposed system is combined precise speed control of PLL and robust, fast speed control of Fuzzy logic. The motor speed is adaptively incremented or decremented toward the PLL locking range by the Fuzzy logic using information of sampled speed errors and then is maintained accurately by PLL. The results of experiment show excellence of proposed system and that the proposed system is appropriates to control the speed of induction motor for electric vehicles.

• Journal of Electrical Engineering and Technology
• /
• 제12권2호
• /
• pp.761-768
• /
• 2017

This paper deals with the performance analysis of three phase induction motor considering its stator side faults and operating thermal limits. The speed control of induction motor using three phase boost converter operated by a MOSFET switch and a PI controller is demonstrated and presented in this article. IGBTs switches are used for inverter drive mechanism. The experimental result of speed control of induction motor using voltage control technique clearly shows better accuracy than conventional methods of speed control. A three phase 1HP 415V 0.78 kW 4 Pole induction motor is designed using motor solver software. Based on the parameters used in the software thermal analysis of induction motor is done and torque variation with conductor area, efficiency, output curve, losses in different parts of motor has been obtained. Also different types of faults namely under voltage, over voltage, stator imbalanced voltage, turn to turn, locked rotor bar, wrong alignment of rotor bar with respect to stator are studied and fault analysis is performed. Hence comparison is made based upon the results obtained before and after faults.

• 제어로봇시스템학회논문지
• /
• 제20권2호
• /
• pp.180-185
• /
• 2014

DC motor is a representative electric motor commonly utilized in various motion control fields. However, DC motor-based motion control systems suffer from degradation of position precision due to nonlinear static friction. In order to enhance control precision, friction model-based compensators have been introduced in previous researches, where friction models are identified and counter inputs are added to control inputs for cancelling out the identified friction forces. In this paper, a static friction compensator is proposed without use of a friction model. The proposed compensation algorithm utilizes internal state manipulation to generate compensation pulses, and related parameters are easily tuned experimentally. The proposed friction compensator is applied to a DC motor-based motion control system, and results are presented in comparison with those without a friction compensator.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
• /
• pp.387-392
• /
• 1999

The micro electronic control technology with developing microcomputers make great contribution to electrohydraulic control systems. The electrohydraulic pulse control simplifies in conjunction with power electronic amplifier and high speed operated solenoid valves. It is necessary to valves to convert electronic pulse signal to hydraulic pulse flow as fast as possible. This study deals with the speed control of an oil hydraulic motor operated by two way high speed solenoid valves. The valves acts as converters of electronic-pulse signals to hydraulic power. By constructing systems in which a hydraulic motor is operated by two solenoid valves, the pulse with modulation method (PWM) has adopted as the speed control of hydraulic motor systems. The static and dynamic characteristics of the systems are investigated by the experiment. It is clarify that a hydraulic motor operated PWM show good performance as a control component, achieving accurate velocity control.

• 전력전자학회논문지
• /
• 제22권3호
• /
• pp.223-230
• /
• 2017

A low-cost BLDC motor with hall sensor is used to drive the position control of a facility security monitoring system in this paper. Low measurable frequency of the hall sensor signal in low-speed regions results in difficulty in obtaining accurate speed detection and position control. To improve system control performance, we propose a variable gain of position controller and stop mode control scheme according to the motor speed and error position with pre-set deceleration time. The proposed stop mode control scheme is activated around the stop position to forcibly move the BLDC motor to the stop position in low speed. In the proposed stop mode, the motor current is controlled by the actual speed with the reference rotating angle. The control performance of the proposed position control is verified through experiments at the actual rail guided facility security monitoring system.

• 산업기술연구
• /
• 제17권
• /
• pp.79-85
• /
• 1997

This paper describes a control for the high performance induction motor drive system with a wide speed operating range and proposes a robust control method independent of motor parameter variation. For the operation below the rated speed, the high performance control is achieved by using the indirect field-oriented control with a speed sensor. In the high speed regain, the field weakening region with a large variation in motor parameters, the motor drive system can obtain the robustness to motor parameter variation by switchover to the direct field-oriented control. Also, the sensorless speed control using estimated speed is achieved in very high speed region that the utilization of speed sensor pulses is limited. And from experiments using high performance 32bit DSP for 2.2[kW] and 22[kW] laboratory induction motor drive systems, it is verified that the proposed opration algorithm provided a good performance.