Abstract：A backstepping error port-controlled Hamiltonian（EPH）controller based on a novel extended state

observer（ESO）was designed to address the issues of insufficient rotor flux observation accuracy and slow system

dynamic response in induction motor speed control. Firstly，an extended state observer was used to observe the

rotor flux，expanding the change in rotor resistance in the model to a new state to improve the accuracy of rotor flux observation. Secondly，using the backstepping control method to obtain the balance point of the stator current of the EPH controller，designing a backstepping EPH controller can effectively improve the dynamic response ability of the EPH control. The experimental results demonstrate that the designed controller has better stability performance and faster response speed compared to the EPH controller.

      Key words：induction motor（IM）；rotor flux；extended state observer（ESO）；backstepping control；error portcontrolled Hamiltonian（EPH）