초록 ▼

A system for controlling circulating currents in a motor. A power supply link having upper and lower rails supplied by a power supply provides power to the motor windings. The power supply link also has power switches responsive to a motor control signal for selectively connecting the rails to the w

A system for controlling circulating currents in a motor. A power supply link having upper and lower rails supplied by a power supply provides power to the motor windings. The power supply link also has power switches responsive to a motor control signal for selectively connecting the rails to the windings in alternating on and off intervals. The system includes a first resistive shunt in the upper rail of the power supply link between the power supply and the power switches and a second resistive shunt in the lower rail of the power supply link between the power supply and the power switches. The power supply link routes current circulating in the power supply link and windings through either the first or second resistive shunt for continuously sensing current in the rails. The system also includes a current regulation circuit which generates an overcurrent signal as a function of the current sensed in either the first or second resistive shunt exceeding a maximum current level. A control circuit responsive to the overcurrent signal causes each of the power switches to become nonconducting thereby to prevent excessive current from circulating in the motor.

대표청구항 ▼

[ What is claimed is:] [1.] A motor system comprising:a stationary assembly including windings;a rotatable assembly in magnetic coupling relation to the stationary assembly;a power supply link for providing power to the windings, said power supply link comprising an inverter bridge having upper and

[ What is claimed is:] [1.] A motor system comprising:a stationary assembly including windings;a rotatable assembly in magnetic coupling relation to the stationary assembly;a power supply link for providing power to the windings, said power supply link comprising an inverter bridge having upper and lower rails supplied by a power supply and having power switches responsive to a motor control signal for selectively connecting the rails to the windings in alternating on and off intervals to produce an electromagnetic field for rotating the rotatable assembly, said power switches each having a conducting state and a nonconducting state;a current sensing circuit for sensing current in each of the rails of the power supply link during both the on and off intervals of the power provided to the windings, said inverter bridge connecting the windings to the upper and lower rails such that current circulating in the power supply link and windings during the off intervals of the power provided to the windings is routed through the current sensing circuit;a current regulation circuit for generating an overcurrent signal as a function of the current sensed in either one of the rails exceeding a maximum current level; anda control circuit responsive to the overcurrent signal for causing each of the power switches to become nonconducting thereby to prevent excessive current from circulating in the motor system.