• 전력전자학회논문지
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• 제17권2호
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• pp.135-141
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• 2012

PMSM(Permanent Magnet Synchronous Motor) has periodic torque ripple from the cogging torque and load conditions. This paper proposes the modified PID speed controller to reduce the speed ripple of the PMSM. The proposed modified PID controller uses a selective D(Differential) control term according to the speed error and the differential of the speed error. The proposed speed controller produces an additional torque reference such as torque compensator based on PI controller according to the speed error and the differential of the speed error, and it can reduce the vibration of the conventional D-control term with reduced speed ripple. Since the additional torque reference of the proposed speed controller is changed by the sign of the speed error and the differential of the speed error, a simple function to determine the sign of the error is used to produce the compensated torque. The proposed control scheme is verified by the computer simulation and the experiments.

• Journal of Electrical Engineering and information Science
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• 제1권2호
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• pp.101-108
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• 1996

A new speed controller based on the fuzzy algorithm with hierarchical structure is presented. The input variables of the controller are speed error and its derivative(change of error), where the output variable is the change of torque current command. Several comparisons were performed with conventional PI (proportional plus integral) controller and proposed controller. These controllers are applied to the laboratory model drive system with 2.2kW induction motor. Some simulation and experimental results show that the speed controller using fuzzy algorithm is more robust than the conventional PI controller.

• Journal of Power Electronics
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• 제5권2호
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• pp.129-141
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• 2005

A high-performance robust hybrid speed controller for a permanent-magnet synchronous motor (PMSM) drive with an on-line trained neural-network model-following controller (NNMFC) is proposed. The robust hybrid controller is a two-degrees-of-freedom (2DOF) integral plus proportional & rate feedback (I-PD) with neural-network model-following (NNMF) speed controller (2DOF I-PD NNMFC). The robust controller combines the merits of the 2DOF I-PD controller and the NNMF controller to regulate the speed of a PMSM drive. First, a systematic mathematical procedure is derived to calculate the parameters of the synchronous d-q axes PI current controllers and the 2DOF I-PD speed controller according to the required specifications for the PMSM drive system. Then, the resulting closed loop transfer function of the PMSM drive system including the current control loop is used as the reference model. In addition to the 200F I-PD controller, a neural-network model-following controller whose weights are trained on-line is designed to realize high dynamic performance in disturbance rejection and tracking characteristics. According to the model-following error between the outputs of the reference model and the PMSM drive system, the NNMFC generates an adaptive control signal which is added to the 2DOF I-PD speed controller output to attain robust model-following characteristics under different operating conditions regardless of parameter variations and load disturbances. A computer simulation is developed to demonstrate the effectiveness of the proposed 200F I-PD NNMF controller. The results confirm that the proposed 2DOF I-PO NNMF speed controller produces rapid, robust performance and accurate response to the reference model regardless of load disturbances or PMSM parameter variations.

• 전자공학회논문지
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• 제51권2호
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• pp.163-167
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• 2014

유압 인버터 엘리베이터의 비선형성과 유압 펌프의 누유량으로 인한 진동 및 속도 편차를 줄이기 위한 부하 보상 및 속도 제어기를 제안하였다. 부하보상 제어기는 PI제어기로 구성하였으며 속도제어기는 PID 제어기를 이용하여 구성하였다. 제어기 제어 변수 이득은 시스템 전달함수의 주파수 응답 방법을 이용하였다. 제안한 제어기의 효용성은 실험을 통해 입증하였고 실험 결과 제안한 제어기는 부하 변동에 강인하고 비선형인 유압 엘리베이터 시스템에 안정하고 좋은 속도 및 가속도 응답 특성을 갖는다.

• Journal of Advanced Marine Engineering and Technology
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• 제20권4호
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• pp.27-35
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• 1996

The ship's propulsion efficiency depends upon a combibation of engine and propeller. The propeller has better efficiency as the engine has lower rotational speed. This situation led the engine manufacures to design the engine that has lower speed, longer stroke and a small number of cylinders. With this new trends the conventional mechanical-hydrualic governors for engine speed control have been replaced by digital speed controllers which adopted the PID control or the optimal control algorithm. But these control algorithms have not enough robustness to suppress the variations of the delay-time and the parameter perturbation especially in low speed engine. In this study we consider the perturbations of the engine parameters as the modeling uncetainties and design a robust speed controller for marine medium speed diesel engine by means of $ extit{H}_{infty}$control theory having the central solution. By comparing the results of the robust speed controller with those of mechanical governor and PID controller, the validity of the robust speed controller under parameter variations is confirmed. The speed control of the experimental diesel engine of carried out using actuator which is composed of PWM signal generator and D.C servo motor.

• Journal of Advanced Marine Engineering and Technology
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• 제20권4호
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• pp.349-349
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• 1996

The ship's propulsion efficiency depends upon a combibation of engine and propeller. The propeller has better efficiency as the engine has lower rotational speed. This situation led the engine manufacures to design the engine that has lower speed, longer stroke and a small number of cylinders. With this new trends the conventional mechanical-hydrualic governors for engine speed control have been replaced by digital speed controllers which adopted the PID control or the optimal control algorithm. But these control algorithms have not enough robustness to suppress the variations of the delay-time and the parameter perturbation especially in low speed engine. In this study we consider the perturbations of the engine parameters as the modeling uncetainties and design a robust speed controller for marine medium speed diesel engine by means of $ extit{H}_{infty}$control theory having the central solution. By comparing the results of the robust speed controller with those of mechanical governor and PID controller, the validity of the robust speed controller under parameter variations is confirmed. The speed control of the experimental diesel engine of carried out using actuator which is composed of PWM signal generator and D.C servo motor.

• 조명전기설비학회논문지
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• 제25권2호
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• pp.69-79
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• 2011

This paper proposes a new fuzzy speed control method based on Takagi-Sugeno fuzzy method of permanent magnet synchronous generators(PMSM) for variable-speed wind turbine systems. The proposed fuzzy speed controller consists of the control terms that compensate for the nonlinearity of PMSG and the control terms that stabilize the error dynamics. The conditions are derived for the existence of the proposed speed controller, and the gain matrices of the controller are given. The proposed control method can guarantee that the PMSG can effectively track the speed reference which is calculated through the MPPT control and can reduce the fluctuations of the generated power under even fast random wind conditions. To verify the performance of the proposed fuzzy speed controller, the simulation results are demonstrated.

• 대한전기학회논문지:시스템및제어부문D
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• 제55권10호
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• pp.443-445
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• 2006

Generally PI controller is used to control the speed of an induction motor. It has the good performance of speed control in case of adjusting the control parameters. But it occurred the problem to change the control parameters in the change of operation condition. In order to solve this problem, Fuzzy control or Artificial neural network is introduced in the speed control of an induction motor. However, Fuzzy control have the problems as the difficulties to change the membership function and fuzzy rule and the remaining error Also Neural network has the problem as the difficulties to analyze the behavior of inner part. Therefore, the study on the combination of two controller is proceeded. In this paper, Fuzzy-neural controller to make up these controllers in parallel is proposed and the speed control of an induction motor is performed using the proposed controller Through the experiment, the fast response and good stability of the proposed speed controller is proved.

• 조명전기설비학회논문지
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• 제19권3호
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• pp.85-92
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• 2005

인버터를 적용한 유압시스템은 펌프의 마찰과 실린더 패킹 및 탑승 카와 레일의 마찰특성으로 인하여 PID 제어기로는 제어가 되지 않는 데드존이 생기게 된다. 본 논문에서는, 우선 유압시스템으로 구동되는 엘리베이터의 극저속 속도영역(zero-crossing)에서 속도가 제어되지 않는 원인이 되는 실린더의 마찰특성을 고찰하고, 이러한 실린더의 마찰특성으로 인하여 기존의 PID 속도제어기로 제어시 발생되는 문제점을 해결하기 위한 줌잉 퍼지룰을 포함한 퍼지제어기를 설계한다. 제안된 하이브리드 퍼지제어기는 정속주행구간에서는 PID제어기를 적용하고 PID제어기로 제어되지 않는 극저속 속도구간에서는 퍼지제어기를 적용하여 유압식 엘레베이터가 실린더의 마찰특성으로 인하여 극저속 속도영역에서 속도가 제어되지 않는 문제를 해결하고, 극저속 영역에서 뿐 아니라 정상상태를 포함한 전 운전영역에서의 제어성능이 우수함을 시뮬레이션과 실험을 통하여 보인다.

• 조명전기설비학회논문지
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• 제28권6호
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• pp.30-39
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• 2014

Through a lot of papers, it has been concluded that fuzzy logic controller is superior to PI controller in motor speed control. Although fuzzy logic controller is superior to PI controller in motor speed control, the gain tuning of fuzzy logic controller is more complicated than that of PI controller. In this paper, using mathematical analysis of the PI and fuzzy controller, the design method of the fuzzy controller that has the same characteristics with the PI controller is proposed. After that, we can design the fuzzy controller that has superior performance than PI controller by changing the envelope of input of fuzzy controller to nonlinear, because the fuzzy controller has more degree of freedom to select the control gain than PI controller. The advantage of fuzzy logic controller is shown through mathematical analysis, and the simulation result using Matlab simulink has been proposed to show the effectiveness of these analysis.