恒压频比变频调速系统的神经网络逆控制

NEURAL NETWORK INVERSE CONTROL OF VARIABLE FREQUENCY SPEED-REGULATING SYSTEM IN V/F MODE

采用以恒压频比方式工作的通用变频器来直接驱动感应电机在工业生产领域中应用很广泛。在不改变原有的恒压频比变频调速系统结构的前提下,进一步提高该系统的控制性能意义很大。该文根据恒压频比控制的特点,把通用变频器和感应电机看成一个整体——恒压频比变频调速系统,给出了相应的数学模型,并得出了适用于带补偿和不带补偿的恒压频比运行方式的逆系统模型,进一步构造神经网络逆系统并与恒压频比变频调速系统串联复合成伪线性系统,再设计线性闭环调节器实现高性能控制。实验结果证明了采用神经网络逆控制方法可以使恒压频比变频调速系统获得优良的运行性能。

The induction motor feeded by a general and low-cost inverter in V/f mode, named as a variable frequency speed-regulating system in V/F, is widely used and its control performance is not good enough to meet the needs of speed-regulating. So it is useful to improve its control performance without changing the original structure of variable frequency speed-regulating system. Considering the induction motor and the inverter as a whole controlled object, this paper gives the mathematic model of the variable frequency speed-regulating system in V/f and its inverse model with or without compensation. Constructing a neural network inverse and combining it with the variable frequency speed-regulating system in V/f complete a pseudo-linear system. Then a linear close-loop adjustor is design to obtain the good speed- regulating performance. Results of experiments demonstrate that speed-regulating performances can be greatly improved using this simple method.