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RISS 인기검색어
- 검색키워드
- 저자 : Tiehua Ma (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
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Yin Shuai,Wang Zhiqiang,Ma Tiehua 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.4
A phase current modulation method that suppresses commutating torque pulsation of brushless direct current motor under non-ideal back EMF was proposed to solve commutating toque ripple problem. This method calculates the duty cycle and commutation time by acquiring the line voltage in real time, and controls the modulation of diff erent duty cycles of the power device to ensure that the on-phase and off -phase current changes at the same rate during commutation, and fi nally suppresses non-commutation phase current pulsates. It assures the consistent change rate of conducting-phase and shut-off phase currents at commutation, and thereby suppresses non-commutation torque ripple. Moreover, the proposed method realized indirect observation of non-ideal back EMF through real-time acquisition of line voltage, which prevents the diffi culty and poor accuracy of observation of back EMF. Comparing with phase current modulation method considering armature resistance, the proposed method can control non-commutation current control at the commutation moment more accurately. The experimental results show that the phase current ripple coeffi cient is only 11.1% at 1000r/min and 13.9% at 2000 r/min, while the phase current ripple coeffi cient under contrast method control is 15.3% at 1000r/min and 19.4% at 2000r/min. The ripple of non-commutation current and commutation torque is smaller at the commutation moment.
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Zhiqiang Wang,Shuai Yin,Tiehua Ma 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.5
The brushless DC motor’s commutation torque ripple is caused by inconsistency in the rate of phase current change. Thus, a method that considers armature resistance is proposed to modulate phase current. The three-phase control strategy, which involves the “open-phase conduction, off-phase pulse width modulation, and maintained non-commutation phase” technique, is applied during commutation at full-speed segments of the motor. Changes in each phase current are analyzed theoretically by establishing mathematical model based on phase current to determine the relative difference among shutdown phase, duty, and motor operating parameters. The turn-on and turn-off phase current change rates are made to be consistent to ensure less non-commutation phase current ripple, then the torque ripple is inhibited. The simulation results show that the phase commutation current and torque ripple coefficient of the proposed method are reduced from 56.9% and 55.5% to 6.8% and 6.1%, respectively. In the experiment system, the pulsation coefficient of the motor phase current is reduced from 40.0% to 16.7% at low speed and 50.0% to 18.8% at high speed. The simulation and experimental results show that the proposed control method significantly inhibits commutation current and torque in the full section.
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Wang, Zhiqiang,Yin, Shuai,Ma, Tiehua The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.5
The brushless DC motor's commutation torque ripple is caused by inconsistency in the rate of phase current change. Thus, a method that considers armature resistance is proposed to modulate phase current. The three-phase control strategy, which involves the "open-phase conduction, off-phase pulse width modulation, and maintained non-commutation phase" technique, is applied during commutation at full-speed segments of the motor. Changes in each phase current are analyzed theoretically by establishing mathematical model based on phase current to determine the relative difference among shutdown phase, duty, and motor operating parameters. The turn-on and turn-off phase current change rates are made to be consistent to ensure less non-commutation phase current ripple, then the torque ripple is inhibited. The simulation results show that the phase commutation current and torque ripple coefficient of the proposed method are reduced from 56.9% and 55.5% to 6.8% and 6.1%, respectively. In the experiment system, the pulsation coefficient of the motor phase current is reduced from 40.0% to 16.7% at low speed and 50.0% to 18.8% at high speed. The simulation and experimental results show that the proposed control method significantly inhibits commutation current and torque in the full section.
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An Efficient Algorithm for the Tensor Product Model Transformation
Jianfeng Cui,Ke Zhang,Tiehua Ma 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.5
The tensor-product (TP) model transformation was proposed recently as a numerical and automaticallyexecutable method which is capable of transforming linear parameter varying (LPV) state-space models into thehigher order singular value decomposition (HOSVD) based canonical form of polytopic models. The crucial disadvantageof the TP model transformation is that its computational load explodes with the density of discretization andthe dimensionality of the parameter vector of the parameter-varying state-space model. In this paper we propose anew algorithm that leads to considerable reduction of the computation in the TP model transformation. The mainidea behind the modified algorithm is to minimize the number of discretized points to acquire as much informationas possible. The modified TP model transformation can readily be executed on a regular computer efficiently andconcisely, especially in higher dimensional cases when the original TP model transformation fails. The paper alsopresents numerical examples to show the effectiveness of the new algorithm.
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