A direct torque control（DTC） system based on the space vector pulse wide modulation（SVM） is developed for the bearingless induction motor

which is multi-variable

nonlinear and high coupling system.The working principles of bearingless induction motor is briefly introduced.The mathematic model of bearingless induction motor is given.The whole control system is divided into rotary control system module and suspension control system module

the method of SVM is introduced into the rotary control system

SVM-DTC is analyzed and realized based on the method of the stator flux vector error;the control system of suspension module is based on PWM inverter in current tracking way.The experiment and simulation results show that the ripples of torque are dramatically reduced and the running performance is more stable

the whole control system has good dynamic and static performance.