• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.11
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• pp.112-122
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• 2014

This paper proposes a PMSM torque control method considering DC-link voltage variation and friction torque. In general EV/HEV application, two dimensions look-up table(2D-LUT) is used for reference current generation due to its stable and robust torque control performance. Conventionally, this 2D-LUT is established by flux-torque table to overcome the DC-link voltage variation. However, the flux table establishment is more complex than the speed table establishment. Moreover, one flux data reflects several speed conditions in variable DC-link voltage, friction torque cannot be considered by using the flux table. In this paper, speed-torque 2D-LUT is used for current reference generation. With this table, PMSM torque control is well achieved regardless of DC-link voltage variation by the proposed control method. Simulation and experimental results validate improvement of torque control error through friction torque compensation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.10
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• pp.1751-1756
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• 2007

This paper presents a high performance pressure control scheme for SR(Switched Reluctance) type hydraulic oil pump using DITC(Direct Instantaneous Torque Control). SR drive has a good feature for pump applications due to a high efficiency, high speed and high torque characteristics. But, SR drive has high torque ripple in commutation region. So, the pump pressure variation is high in the region. In order to reduce the pressure variation, DITC combined with pressure control scheme is presented in this paper. A simple PI controller with flow and pressure limit, generates a reference torque to keep the constant actual pump pressure. The direct torque controller of SR drive generates inverter switching signals according to a control rule and a torque estimator. Computer simulation and experiemtal results show the validation of the proposed control scheme.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.2
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• pp.252-260
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• 1997

In this paper, a friction compensation method using a disturbance observer is proposed for an impedance control of pneumatic manipulator. It is assumed that the generated torque by a pneumatic actuator can be estimated based on the pressure signals and the discharge volume. In order to improve the dynamic characteristics of the pneumatic actuator driven by meter out method, we construct the inner torque control system by feeding back the generated torque. In order to reduce the influence of disturbances comprising friction torque and parameter variations of plant, the impedance control system is constructed with a disturbance observer which estimates the disturbances based on the generated torque of pneumatic actuator, the angular velocity and the reaction torque. From some experiments, it is confirmed that the proposed control system is effective to improve the robustness for the friction torque in the impedance control of a pneumatic manipulator.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.197-199
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• 1998

A neuro-fuzzy based torque profile model of SRM with considerably improved accuracy is obtained using the measured data for training. The inferred torque profiles, which comprise magnetic non-linearities, represent the dynamic model of SRM. Then the reference torque signal with optimized waveform and switching angle are decided to control the torque directly. Hence, the presented scheme controls the torque in an instantaneous basis, allowing powerful torque control with minimum torque ripple even during the transient operation of the motor. Simulation and experimental results demonstrating the effectiveness of the proposed torque control scheme are presented.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.5B no.2
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• pp.173-180
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• 2005

The construction of a Synchronous Reluctance Motor (SynRM) is simple and also highly economical because a stator from the existing AC motor can be used. Since the synchronous inductance in the Synchronous Reluctance Motor is an element that is proportional to torque, its exact value must be experimentally or analytically found for accurate control and performance development of the motor. In this paper, direct torque control (DTC) simulation is carried out to maximize the torque of the Synchronous Reluctance Motor and the fast response characteristics with the inductance value by the Finite Element Method (FEM). The response characteristics are compared through the proposed direct torque control and torque response characteristics that are based on the existing PI Control in order to confirm the fast response features. To test the performance of the direct torque controller, the torque response is analyzed with variable speed and load condition.

• The KSFM Journal of Fluid Machinery
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• v.15 no.2
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• pp.30-35
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• 2012

Aerodynamic torque of wind turbine has nonlinear properties. Nonlinearity of aerodynamic torque is very important in wind turbine in the aspect of control. The traditional torque control method using optimal mode gain has been applied in many wind turbines but its response is slower as wind turbine size is larger. In this paper, a torque control method using a nonlinear parameter of rotor speed among nonlinear properties of aerodynamic torque. Simulink model is implemented to obtain the nonlinear parameter of rotor speed and numerical simulations for a 2MW wind turbine are carried out and simulation results for the traditional and proposed torque control methods are compared.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.2
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• pp.145-150
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• 2010

This paper deals with reduction of torque ripple in a brushless DC motor with input voltage control. The commutation torque ripple can be controlled with varying input voltage, but cogging torque is independent on it. So, in this paper a strategy for minimizing torque ripple is proposed by offsetting the cogging torque with deliberate voltage control. The optimal condition is determined with variable voltage levels and advance angles. As results, it is shown that the method causes 63% decrease of torque ripple.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.87-90
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• 2006

The direct instantaneous torque control (DITC) method is presented in this paper, which enables torque to be generated during all region and instantaneous torque control to be possible. The hysteresis control mode with the compared value between given torque and instantaneous output torque as input is applied in respect region. The output torque function, that is instantaneous output torque with the variation of current and position of rotor, is achieved by experiment. In this control mode the torque subsection function and current control are not needed. The turn on angle with variation of load torque and speed is only selected and turn off angle can be neglected. The validity of method is tested by simulation and experiment.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.427-432
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• 2003

The control method of programmable dynamometer for overall test of machine is to load the reference torque which is computed from torque transducer into motor under test. But the torque information detected from torque transducer have a lot of noise when the load torque of moter is a small quantity or changing. Thus, torque transducer must have a low pass filter to detect a definite torque information. But The torque delay generated by filter with torque transducer occur a torque trouble for meter torque of programmable dynamometer. The proposed system improved the problem of the torque measuring delay with torque transducer, and the load torque is estimated by the minimal order state observer based on the torque component of the vector control induction meter. Therefore, the torque controller is not affected by a load torque disturbance.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1108-1110
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• 2003

The control method of programmable dynamometer for overall test of machine is to load the reference torque which is computed from torque transducer into motor under test. But the torque information detected from torque transducer have a lot of noise when the load torque of meter is a small quantity or changing. Thus, torque transducer must have a low pass filter to detect a definite torque information. But The torque delay generated by filter with torque transducer occur a torque trouble for meter torque of programmable dynamometer. The proposed system improved the problem of the torque measuring delay with torque transducer, and the load torque is estimated by the minimal order state observer based on the torque component of the vector control induction moter. Therefore, the torque controller is not affected by a load torque disturbance.