Technical solutions are described for a motor control system of a motor to compute a disturbance estimate and use the disturbance estimate to improve the performance of the motor control system. For example, the motor control system includes an observer module that receives an input voltage signal of the motor. The motor control system also receives an output current signal from the motor. The motor control system further computes the disturbance estimate of the motor control system based on a plant model of an electrical subsystem of the motor control system.