VACUUM SYSTEM

摘要

A vacuum system 10 comprises a vacuum pump 12 for evacuating a tool or chamber. The vacuum pump 12 is driven by an electric motor 14 which is typically arranged to rotate one or more rotors of the vacuum pump, dependent on varying pumping requirements. Electrical energy for driving the motor 14 is supplied from an electrical supply, typically a mains electrical supply. A control 16 controls the transfer of energy to the motor. The control is typically a power electronic controller, which comprises a rectifier for converting AC electrical energy from the supply to DC energy and an inverter for converting DC energy into an appropriate AC form for controlling rotation by the motor. The control is arranged to control the magnetic flux generated in the electric motor and the value of cooling applied by the cooling arrangement dependent on the values of flux, cooling and power and/or torque. The control may be arranged to receive an input from a sensor 22 arranged to sense the temperature of the vacuum system or the temperature of one or more components of the vacuum system