Method for suppressing fluctuation of bus voltage of electrolytic capacitor-free frequency converter based on neural network

The invention discloses a method for suppressing the fluctuation of a bus voltage of an electrolytic capacitor-free frequency converter based on a neural network. The method comprises the following steps: firstly, a q-axis current expression is solved according to a power balance equation; a d-axis current control strategy is formulated according to a relationship that a voltage of a motor cannot be higher than a voltage which can be provided by an inverter; secondly, segmented logic is used, and a dynamic reference speed is given according to whether the bus voltage exceeds a threshold value or not; and finally, the BP neural network is built, the value of the fluctuation of the bus voltage serves as a performance index, dynamic reference speeds given by the segmented logic under different threshold values are subjected to data optimization, the neural network is trained to output the optimal dynamic reference speed, and the fluctuation of the bus voltage is suppressed. On the basis of a traditional electrol