On the sensorless synchronous direct drive control of permanent magnet motor for three-blade roots vacuum pump

Abstract

Different from the traditional permanent magnet motor, the permanent magnet motor for three blade roots vacuum pump (PMM for TBRVP) is difficult to use sensors (or encoders) to achieve multi-motor collaborative control due to its special structure, extreme operating environment and harsh operating reliability requirements; Considering the high failure rate of mechanical structures such as gearboxes, direct drive PMM for TBRVP is becoming mainstream. To this end, a 1.5 kW epoxy resin sealed vacuum pump permanent magnet motor is designed, the key parameters (resistance, inductance, flux, etc.) of a single motor and the non-sensory control system are determined based on the prototype experiment, and then the dual motor collaborative control model is designed, and the deviation coupling multi-motor synchronous control strategy based on the virtual motor is designed. The analysis of four typical working conditions shows that the maximum rotor position following error between the motors is 2.29° (far lower than the critical value of 5°), and has good anti-interference ability.

Keywords

• Vacuum dry pump
• Sensorless
• Multi-motor control
• Synergistic direct drive