An Encoderless Predictive Torque Control for an Induction Machine With a Revised Prediction Model and EFOSMO

Recently, model predictive torque control (MPTC) has been introduced as a powerful control method for induction motor (IM) drives. However, the weighting factor for stator flux must be tuned carefully to obtain satisfactory performance at different operation points. Unfortunately, so far the tuning of weighting factor in MPTC is mostly based on empirical procedure. This paper solves this problem by proposing a model predictive flux control (MPFC), which uses the stator flux vector as the control variable and eliminates the complicated prediction of stator current at k+2 instant. As a result, the weighting factor in conventional MPTC is eliminated and the control complexity is significantly reduced. Both MPTC and MPFC are tested and compared in detail, including steady state performance, dynamic response and low speed operation. The simulation and experimental results prove that, the performance of conventional MPTC is dependent on the weighting factor and improper weighting factor would lead to significant performance deterioration. On the contrary, the proposed MPFC achieves similar or even better overall performance over a wide speed range with very low tuning work. Hence, it is concluded that the proposed MPFC is more practical than conventional MPTC.

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“…In fact, this assumption is a common practice in most study regarding MPTC, as shown in [5], [23]- [25], [27], [28], [30], [31], [38].…”

Section: B Vector Selectionmentioning

confidence: 98%

Model-Predictive Control of Induction Motor Drives: Torque Control Versus Flux Control

Zhang

Yang

Xia

2016

IEEE Trans. on Ind. Applicat.

142

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“…Field-oriented control (FOC) and direct torque control (DTC) are the two most popular methods for high performance AC motor drives. Compared to FOC, the DTC has fast dynamic response and simple structure, due to lack of inner current regulators, rotary Manuscript received December 20, 2014; revised March 9, 2015; accepted July 20, 2015. The authors are with the department of electrical engineering, faculty of engineering, University of Isfahan, Isfahan, Iran (e-mails: mh.vafaie@eng.ui.ac.ir, mirzaeian@eng.ui.ac.ir, p_moallem@eng.ui.ac.ir, kiyoumarsi@eng.ui.ac.ir) coordinate transformation blocks and pulse width modulation (PWM) block [3]- [4]. Takahashi and Depenbrock propose the DTC method to control an induction motor [5]- [6] and due to its advantages (above), it is extended to be applied in PMSM and other synchronous motor drives [7]- [8].…”

Section: Introductionmentioning

confidence: 99%

A New Predictive Direct Torque Control Method for Improving Both Steady-State and Transient-State Operations of the PMSM

Vafaie

Dehkordi

Moallem

et al. 2016

IEEE Trans. Power Electron.

125

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In this paper, a new predictive direct torque control (DTC) method is proposed, improving the dynamic response of the classical DTC and reducing the torque-and flux-ripples through a voltage vector with optimal phase. In the transientstate, the voltage vector phase is selected in a manner where the fastest dynamic response is achieved, while in the steady-state, this phase is selected in a manner where the stator flux amplitude reaches its commanding value at the end of the control cycle. In the steady-state, the selected vector is applied to the motor with an optimal time duration calculated to achieve the minimum torque ripple. The five-segment space-vector modulation is used to synthesize the voltage vector, where a fixed switching frequency is obtained. To investigate the effectiveness of the proposed method, steady-state and transient-state performances are tested in MATLAB software and in practice. Both the simulation and experimental results confirm that the proposed method reduces the torque and flux ripples effectively while improving the dynamic response of the classical DTC method. The comparative investigation of the proposed method with the recent DTC methods indicates that the proposed method has lower ripples in the steady-state and a faster dynamic response in the transient-state.Index Terms-Direct torque control, permanent-magnet synchronous motor drives, predictive torque control, steady-state operation, transient-state operation. 0885-8993 (c)

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“…The control targets for controlling a parallel connected AFEs are: (I) DC-link voltage control, i.e., maintaining a constant DC-link voltage against different load side conditions; (II) grid side power factor and power (current) quality control; (III) maintain the phase currents on different modules balanced (i.e., keep i x1 n = i x2 n , where x can a, b, or c, represents the phases of the grid side converter). And to fulfill (I) and (II), the control schemes in general can be divided into four groups [6]- [8]: (i) Vector control with modulator, (ii) direct control with look-up table; (iii) direct control with modulator, (iv) predictive control (direct and continuous predictive control [9]- [13]). Vector control is dominating the most industrial applications.…”

Section: Introductionmentioning

confidence: 99%

Current balancing control of high power parallel-connected AFE with small current ripples

Cai

Zhang

Cai³

et al. 2015

2015 9th International Conference on Power Electronics and ECCE Asia (ICPE-ECCE Asia)

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Parallel connected Active Front End (AFE) voltage converters are widely employed in high-power grid interfaces for renewable energy applications. With parallel connected two level power converters, the power rating of the system can be easily increased with higher stability and less control efforts than multilevel power converter based solutions. However, due to unmatched modules, unbalanced currents inevitably happen to different modules of the same phase, which seriously impacts the efficiency and performances of the converter. This paper presents an improved current balancing control methods for a high power (600 kVA) parallel connected AFE for wind energy applications. The proposed current balancing method is integrated within a well-known Voltage Oriented Control Scheme with few implementation efforts. The simulation results show that with the proposed strategy the current ripples of each parallelconnected converter leg decrease evidently and the THDs are therefore decreased. Moreover, the effectiveness of the proposed method is also confirmed by experimental results with a grid-code compatible testing set-up.

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An Encoderless Predictive Torque Control for an Induction Machine With a Revised Prediction Model and EFOSMO

Cited by 80 publications

References 31 publications

Model-Predictive Control of Induction Motor Drives: Torque Control Versus Flux Control

Model-Predictive Control of Induction Motor Drives: Torque Control Versus Flux Control

A New Predictive Direct Torque Control Method for Improving Both Steady-State and Transient-State Operations of the PMSM

Current balancing control of high power parallel-connected AFE with small current ripples

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