On the issue of control system adjustment of a direct current drive on the modular optimum. Part 1

Resumo

A mathematical model of a two-loop control system of a dc drive with a control unit realized on the basis of the widely used P and PI controllers was obtained. The optimized parameters of the system are the gain coefficients of the current and speed closed loops and coefficients of the integral components of the corresponding controllers. Two variants of optimization of the system structure and parameters are considered: (1) standard consecutive adjustment of the current and speed loops to the modulus optimum, which leads to a static control system with a P speed controller and a PI current controller; and (2) system adjustment to the modulus optimum as a united whole, which leads to an astatic system with a PI speed controller and a P current controller or without a current controller with proportional current feedback to the power converter input. The formulas for optimal values of adjustable parameters for both variants are obtained. It was shown for instance by simulation in Matlab–Simulink that the system adjusted in accordance with the second variant has better performance indices, such as offset, transient time, and overshooting at a changing set point and disturbance variable.