In order to solve the problem of slow response and poor anti-interference ability in permanent magnet synchronous motor (PMSM) speed regulation system

a new fractional reaching rate sliding mode control strategy was proposed. The approach law combines the variable exponential power term with the traditional exponential approach law

and relates the state variables of the system to the exponent of the power term

it can also solve the problem of large chattering when the traditional exponential reaching law approaches the sliding mode surface. In addition

the extended state observer (ESO) based on the new nonlinear function is used to observe the disturbance term of the system accurately

and the observations are fed forward to the new sliding mode controller to enhance the anti-disturbance ability of the system. At the same time

a new sliding mode load torque observer is designed to observe the load torque changes in real time and feedback the observed values to ESO to further improve the robustness of the system. The simulation results show that the anti-jamming ability of the system is improved and the dynamic and steady performance is better after adopting the new fractional reaching law sliding mode control strategy.