Open AccessPredictive torque control for voltage source inverter‐permanent magnet synchronous motor based on equal torque effect
Author(s) -
Xia Changliang,
Qiu Xudong,
Wang Zhiqiang,
Shi Tingna
Publication year - 2016
Publication title -
iet electric power applications
Language(s) - English
Resource type - Journals
ISSN - 1751-8679
DOI - 10.1049/iet-epa.2015.0310
Subject(s) - control theory (sociology) , torque , direct torque control , duty cycle , weighting , voltage , inverter , damping torque , stall torque , model predictive control , computer science , engineering , physics , induction motor , control (management) , electrical engineering , artificial intelligence , acoustics , thermodynamics
In this paper, equal torque effect (ET‐effect) is discovered, which means that the same torque can be obtained by applying different voltage vectors whose terminals locate on a special curve called the equal torque curve (ET‐curve). By means of ET‐effect, an improved predictive torque control (PTC) without weighting factor is proposed. First, to obtain the volt‐sec vectors whose terminals locate on the ET‐curve, the proposed PTC calculates the duty cycles of all the voltage vectors intersected with the ET‐curve, and then establishes finite control set by accumulating those volt‐sec vectors. Second, a cost function that includes only the flux error is defined to select the optimal volt‐sec vector, and thus to avoid weighting factor adjustment since the torque error no longer exists in the cost function. Because of the two‐step optimisation of torque and flux, the proposed PTC can avoid the problem that the duty cycle cannot be fully utilised in standard PTC. As a result, the proposed PTC achieves better performance of torque and flux than standard PTC and PTC with duty cycle. Finally, experiments have been carried out to validate the proposed PTC strategy.