tailieunhanh - A neural-network-based space-vector PWM controller for a three-level voltage-fed inverter induction motor drive

A neural-network-based space-vector PWM controller for a three-level voltage-fed inverter induction motor drive | 660 IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS VOL. 38 NO. 3 MAY JUNE 2002 A Neural-Network-Based Space-Vector PWM Controller for a Three-Level Voltage-Fed Inverter Induction Motor Drive Subrata K. Mondal Member IEEE Joao O. P. Pinto Student Member IEEE and Bimal K. Bose Life Fellow IEEE Abstract A neural-network-based implementation of space-vector modulation SVM of a three-level voltage-fed inverter is proposed in this paper that fully covers the linear undermodulation region. A neural network has the advantage of very fast implementation of an SVM algorithm particularly when a dedicated application-specific IC chip is used instead of a digital signal processor DSP . A three-level inverter has a large number of switching states compared to a two-level inverter and therefore the SVM algorithm to be implemented in a neural network is considerably more complex. In the proposed scheme a three-layer feedforward neural network receives the command voltage and angle information at the input and generates symmetrical pulsewidth modulation waves for the three phases with the help of a single timer and simple logic circuits. The artificial-neural-network ANN -based modulator distributes switching states such that neutral-point voltage is balanced in an open-loop manner. The frequency and voltage can be varied from zero to full value in the whole undermodulation range. A simulated DSP-based modulator generates the data which are used to train the network by a backpropagation algorithm in the MATLAB Neural Network Toolbox. The performance of an open-loop volts Hz speed-controlled induction motor drive has been evaluated with the ANN-based modulator and compared with that of a conventional DSP-based modulator and shows excellent performance. The modulator can be easily applied to a vector-controlled drive and its performance can be extended to the overmodulation region. Index Terms Induction motor drive neural network space-vector pulsewidth modulation three-level inverter. .