Design of comprehensive motor protector based on improved sliding-window iterative DFT algorithm

摘要

This paper introduces a design of comprehensive motor protector based on improved sliding-window iterative discrete fourier transform (DFT) algorithm. It improves the conventional sliding-window iterative DFT, making it easier in calculation and reducing the computation burden of the microprocessor. With electric parameters updating every sampling period, the time response to faults is much improved, compared to the conventional motor protector. For the hardware plan, the protector is controlled by two microcontrollers, one is for the control and measurement module and the other is for the display module. They are connected through RS422 communication. The whole device is compact and layout reasonable, with the advantages of small size and high reliability. The motor protector designed in this paper integrates protection, control, measurement, and communication. Experiment results have verified that it has good performance and high accuracy and can provide comprehensive protection for the motor.