scholarly journals Model Predictive Current Control Strategy with Reduced Computation Burden

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jie Yuan ◽  
Dingdou Wen ◽  
Yang Zhang
Keyword(s):  
Steady State ◽  
Duty Cycle ◽  
Dynamic Performance ◽  
Current Control ◽  
Computational Burden ◽  
The Third ◽  
Voltage Vector ◽  
Control Scheme ◽  
The Cost ◽  
Steady State Performance

In this paper, three model predictive current control (MPCC) schemes for permanent magnet synchronous motors (PMSM) are studied. The first control scheme is the traditional optimal duty cycle model predictive current control (ODC-MPCC). In this scheme, according to the principle of minimizing the cost function, the optimal voltage vector is selected from the six basic voltage vectors which are optimized simultaneously with the duty, and then, the optimal voltage vector and its duty are applied to the inverter. In order to reduce the computational burden of ODC-MPCC, a second control scheme is proposed. This scheme optimizes the voltage vector control set, reducing the number of candidate voltage vectors from 6 to 2. Finally, according to the principle of minimizing the cost function, the optimal voltage vector is found from the two voltage vectors, and the optimal voltage vector and its duty cycle are applied to the inverter. In addition, in order to further improve the steady-state performance, another vector selection method is introduced. In the combination of voltage vectors, the third control scheme extends the combination of voltage vectors in the second control scheme. The simulation results show that the second control scheme not only reduces the computational burden of the first control scheme but also obtains steady-state performance and dynamic performance equivalent to the first control scheme. The third control scheme obtains better steady-state performance without significantly increasing the computational burden and has dynamic performance comparable to the first and second control schemes.

Enhanced Model Predictive Current Control Based on Runge–Kutta Approximation for a Voltage Source Inverter

2019 ◽  
Vol 20 (4) ◽  
Author(s):  
Shahrouz Ebrahimpanah ◽  
Qihong Chen ◽  
Liyan Zhang
Keyword(s):  
Duty Cycle ◽  
Control Period ◽  
Sampling Frequency ◽  
Current Control ◽  
Voltage Source ◽  
Discrete Time System ◽  
Voltage Vector ◽  
Runge Kutta ◽  
Current Error ◽  
The Cost

Abstract This paper proposes a model predictive current control (MPCC) method with duty cycle control based on the Runge–Kutta approximation compared to the Forward Euler Approximation for grid-connected three-phase inverters with output LCL filter. Hence, results of proposed MPCC methods alongside of the conventional MPCC have been investigated to find the best strategy. First, all 7 possible switching states have been checked by the discrete-time system model based on two approximation methods to select a state that minimizes the cost function. However, at this stage only one voltage vector is chosen during one control period, which cannot decrease the current ripples to a minimum value. Hence, for having sufficient performance, the sampling frequency is necessary to be selected high. Then, the idea of duty cycle optimization has been introduced by using two voltage vectors (a non-zero and a zero voltage vector) during one control period. Therefore, the duration of two voltage vectors have been defined according to the principle of current error minimization. Finally, the effectiveness of the proposed MPCC method based on the Runge–Kutta approximation has been verified by MATLAB/Simulink and experimental results exhibit a better steady-state performance with less sampling frequency as compared to the conventional strategy.

scholarly journals A General Double Vector-Based Model Predictive Current Control for the Dual Three-Phase Motors

Electronics ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 2000
Author(s):  
Qingqing Yuan ◽  
Ting Ma ◽  
Renji Zhao ◽  
Yumei Yang
Keyword(s):  
Duty Cycle ◽  
Control Period ◽  
Current Control ◽  
Control Performance ◽  
Delay Compensation ◽  
Voltage Vector ◽  
Three Phase ◽  
Speed Range ◽  
Full Speed ◽  
The Cost

Traditional model predictive current control (MPCC) for motors can only choose one optimal voltage vector during one control period, which creates problems of over-regulation or under-regulation for the current tracking. With zero vectors being injected in the chosen optimal voltage vector, the traditional MPCC can obtain better performance, which is called duty cycle MPCC. However, whether the traditional or the duty cycle MPCC is being applied to multiphase motors, it is more difficult for the phase to increase. In this paper, a general double vector-based MPCC mechanism has been studied for a dual three-phase permanent synchronous motor (PMSM) with dual Y shift 30° windings used in aerospace propulsion. Firstly, the choosing range of the second voltage vector in duty cycle MPCC was extended to an arbitrary vector; then, the cost function was rationally designed, and the delay compensation was added to improve the control performance as well. Compared with the traditional or duty cycle MPCC, this general double vector-based MPCC has better torque performance and fewer total harmonic distortions in the full speed range and under different load conditions.

scholarly journals Sparse Adaptive Channel Estimation Based onlp-Norm-Penalized Affine Projection Algorithm

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yingsong Li ◽  
Wenxing Li ◽  
Wenhua Yu ◽  
Jian Wan ◽  
Zhiwei Li
Keyword(s):  
Steady State ◽  
Channel Estimation ◽  
Convergence Speed ◽  
Projection Algorithm ◽  
Broadband Wireless ◽  
Sparse Channel Estimation ◽  
Affine Projection ◽  
Affine Projection Algorithm ◽  
The Cost ◽  
Steady State Performance

We propose anlp-norm-penalized affine projection algorithm (LP-APA) for broadband multipath adaptive channel estimations. The proposed LP-APA is realized by incorporating anlp-norm into the cost function of the conventional affine projection algorithm (APA) to exploit the sparsity property of the broadband wireless multipath channel, by which the convergence speed and steady-state performance of the APA are significantly improved. The implementation of the LP-APA is equivalent to adding a zero attractor to its iterations. The simulation results, which are obtained from a sparse channel estimation, demonstrate that the proposed LP-APA can efficiently improve channel estimation performance in terms of both the convergence speed and steady-state performance when the channel is exactly sparse.

Technique of Digital SPWM Inverter Based on PRE Control

2013 ◽  
Vol 860-863 ◽  
pp. 2351-2355
Author(s):  
Jie Zhang ◽  
Hong Wei Ma
Keyword(s):  
Steady State ◽  
Single Phase ◽  
Stable Operation ◽  
Operation Condition ◽  
Control Scheme ◽  
Single Phase Inverter ◽  
Fast Dynamic ◽  
Input Error ◽  
Steady State Performance ◽  
Repetitive Controller

A PRE control scheme in single-phase inverter is adopted, namely connecting the proportional component with repetitive controller in parallel. This control scheme not only retains the characteristics of fast dynamic response from proportion link ,but also absorbs the advantages of no steady-state error in repetitive control .When the system is in stable operation condition, repetitive controller is used to resist periodic disturbance and thus improve the steady-state performance. Contrarily, the proportional component can feel mutation of input error and produce accommodation immediately to ensure the systems fast speed of response .The comprehensive theoretical analysis of this control strategy is given, and the system is designed in Matlab based on this theory, besides, the control scheme is achieved in the DSP platform by using digital control algorithm. Simulation and experimental results prove that the proposed scheme can achieve good dynamic and steady-state performance.

scholarly journals Model Predictive Voltage Control with Optimal Duty Cycle for Three-Phase Grid-Connected Inverter

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Shahrouz Ebrahimpanah ◽  
Qihong Chen ◽  
Liyan Zhang ◽  
Misbawu Adam
Keyword(s):  
Steady State ◽  
Duty Cycle ◽  
Tracking Error ◽  
Voltage Control ◽  
Sampling Period ◽  
Sampling Interval ◽  
Nonlinear Load ◽  
Three Phase ◽  
Switching State ◽  
Steady State Performance

This paper proposes a model predictive voltage control (MPVC) strategy with duty cycle control for grid-connected three-phase inverters with output LCL filter. The model of the system is used to predict the capacitor filter voltage according to the future output current for each possible switching state at each sampling period. Then the cost function for each prediction is determined and the switching state is selected. In the proposed method, two voltage vectors are applied during one sampling interval to achieve better steady-state performance. Finally, the optimal duration of the nonzero voltage vector is defined based on the duty cycle optimization, which is vital to the control system. The proposed strategy offers a better reference tracking error with less THD in linear and nonlinear load situations. The effectiveness of the proposed method has been verified by MATLAB/Simulink and experimental results exhibit a better steady-state performance with less sampling frequency.

scholarly journals Current Prediction-Based Three-Vector Voltage Optimization System for the Induction Motor with Current Static Error Correction

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Li Haixia ◽  
Lin Jican
Keyword(s):  
Steady State ◽  
Model Predictive Control ◽  
Induction Motor ◽  
Predictive Control ◽  
Control Method ◽  
Tracking Error ◽  
Current Control ◽  
Static Error ◽  
Control Stability ◽  
Steady State Performance

In the present study, the current control method of the model predictive control is applied to the field-oriented control induction motor. The augmentation model of the motor is initially established based on the stator current equation, which performs the current predictive control and formulates the new cost function by means of tracking error. Then, the influence of parameter error on the current control stability in the prediction model is analysed, and the current static error is corrected according to the correlation between the input and feedback. Finally, a simple and effective three-vector control strategy is proposed. Moreover, three adjacent basic voltage vectors are utilized, and then six candidate voltage vectors are synthesized in each sector to replace eight basic voltage vectors in the conventional model predictive control (MPC). The obtained results show that synthesized vectors, which have arbitrary amplitude and direction, significantly expand the coverage of the system’s control set, reduce the torque and flux pulsation in the conventional MPC, and improve the steady-state performance of the system. Finally, the dSPACE platform is employed to validate the performed experiment. It is concluded that the proposed method can reduce the torque and flux pulse, perform the induction motor current control, and improve the steady-state performance of the system.

Static and Dynamic Performance of an Infinite Stiffness Hydrostatic Thrust Bearing

1977 ◽  
Vol 99 (1) ◽  
pp. 106-112 ◽  
Author(s):  
N. Tully
Keyword(s):  
Steady State ◽  
Vibration Analysis ◽  
Thrust Bearing ◽  
Dynamic Performance ◽  
Cone Angle ◽  
Vibration Absorber ◽  
Static Stiffness ◽  
Load Range ◽  
Normal Diaphragm ◽  
Steady State Performance

A novel form of variable hydrostatic restriction is proposed which will automatically achieve a high, infinite or negative static stiffness over a substantial load range. The restrictor is formed between the bearing body and a spring mounted conical plug. The steady state performance is analyzed and design curves presented which are valid for any cone angle from zero, i.e., fixed clearance, to 90 deg which is the normal diaphragm restrictor. The dynamic response to forced sinusoidal vibrations is examined in conventional vibration analysis form and it is found that the restrictor system may be designed to act as a vibration absorber.

A Self-Excited Synchronous Motor with Controlled Excitation

1986 ◽  
Vol 23 (2) ◽  
pp. 127-132
Author(s):  
T. F. Chan
Keyword(s):  
Steady State ◽  
Power Factor ◽  
Synchronous Motor ◽  
Experimental Results ◽  
Direct Connection ◽  
Excitation Control ◽  
Motor Power ◽  
Control Scheme ◽  
Bridge Rectifier ◽  
Steady State Performance

An excitation control scheme for a two-axis excited synchronous motor is described, which, by the direct connection of the quadrature field winding and the armature circuit through a diode bridge rectifier, enables the motor power factor to be maintained at approximately unity, irrespective of load. The steady-state performance based on a simple phasor diagram is verified by experimental results.

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