Motor control system

Claim 2

In a motor control system for a motor including a circuit for conducting motor current to effect electrical driving of the motor, a contactor having contacts in said circuit for making and breaking the circuit to the motor on the starting and stopping of the motor, control means actuatable to initiate and stop the electrical operation of the motor, first means actuated to first and second states in response to said control means to respectively make and break said circuit on the starting and stopping of motor operation, second means for sensing a condition of said motor, and third means responsive to said second means for inhibiting actuation of said first means from one of said states to the other until the cessation of said condition.

Claim 3

In a motor control system as defined in claim 1 wherein said third means comprises means inhibiting the actuation of said first means from its second state to its first state in the presence of said condition.

Claim 4

In a motor control circuit as defined in claim 1 wherein said second means comprises means for sensing a condition dependent on rotation of said motor and preventing the actuation of said first means to a state to start said motor while said motor is rotating.

Claim 5

In a motor control circuit as defined in claim 3 wherein said condition is the electromotive force generated by said motor when rotated by an external force.

Claim 6

In a motor control system according to claim 3 wherein said third means comprises means inhibiting the actuation of said first means from its state for stopping said motor in the presence of said condition.

Claim 7

An electrical control system as defined in claim 1 wherein said third means comprises first circuitry for inhibiting the actuation of said first means from said first state to said second state and said second means comprises means responsive to current flowing in said motor.

Claim 8

A control circuit as defined in claim 2 in which said third means has a first state for inhibiting said first means from changing states and comprises first and second input terminals for respectively receiving an operate signal and a condition signal indicative of said condition, said first means comprising logic means having a first state in the absence of an operate signal and a signal indicative of said condition and being actuated to said second state in response to the presence of said operate signal and the absence of a condition signal and being returnable to said first state in the absence of an operate signal and the absence of said condition signal.

Claim 9

An electrical control system as defined in claim 3 wherein said second means comprises means responsive to current flowing in said motor.

Claim 10

In a motor control circuit as defined in claim 7 wherein said second means comprises means for sensing a condition dependent on rotation of said motor and preventing the actuation of said first means to a state to start said motor while said motor is rotating.

Claim 11

A control circuit as defined in claim 9 wherein said second means includes means for sensing armature current.

Claim 12

In a motor control system as defined in claim 1 including means for providing a speed command signal for said motor, speed control means responsive to said signal for controlling the conduction of current to said motor in response to said command signal, and control circuitry means responsive to the actuation of said first means to its state for energizing said motor to effect connection of said speed command signal to said speed Responsive means.

Claim 13

In a motor control system as defined in claim 11 wherein said condition comprises the counter-electromotive force of said motor and said third means inhibits operation of said first means to effect operation of said contactor to make said circuit.

Claim 14

In a motor control system, control means for starting and stopping a motor comprising first means actuatable between first and second states to energize and de-energize the motor, second means for sensing a condition of said motor, third means responsive to said second means for inhibiting said first means from being actuated from one state to another state until the cessation of said condition, means for providing a speed command signal for said motor, speed control means responsive to said signal for controlling the conduction of current to said motor in response to said command signal, control circuitry means responsive to the actuation of said first means to its state for energizing said motor to effect connection of said speed command signal to said speed responsive means, said control means comprising means settable to apply an operate signal to said first means for effecting actuation thereof to its state for energizing said motor and stop means actuatable to interrupt said operate signal to stop said motor and including speed signal control means actuated on the actuation of said stop means to immediately disconnect said speed command signal, and said third means comprising means responsive to said condition to inhibit actuation of said first means to its state for de-energizing said motor in the presence of said condition.

Claim 15

In a motor control system, control means for starting and stopping a motor comprising first means actuatable between first and second states to energize and de-energize the motor, second means for sensing a condition of said motor, third means responsive to said second means for inhibiting said first means from being actuated from one state to another state until the cessation of said condition, means for providing a speed command signal for said motor, speed control means responsive to said signal for controlling the conduction of current to said motor in response to said command signal, control circuitry means responsive to the actuation of said first means to its state for energizing said motor to effect connection of said speed command signal to said speed responsive means, said control means comprising means settable to apply an operate signal to said first means for effecting actuation thereof to its state for energizing said motor and stop means actuatable to interrupt said operate signal to stop said motor and including speed signal control means actuated on the actuation of said stop means to immediately disconnect said speed command signal, and said third means comprising means responsive to said condition to inhibit actuation of said first means to its state for de-energizing said motor in the presence of said condition.

Claim 16

In a motor control system as defined in claim 13 wherein said condition comprises armature current flowing in said motor.

Claim 17

In a motor control system as defined in claim 13 wherein said system comprises a power converter for supplying rectified alternating current power to said motor in response to said speed command signal and a second power converter for transmitting power from said motor when the motor is operating in a regenerative mode, said first and second power converters including inhibit terminals for receiving an inhibit signal which inhibits operation of the power converters, said control means comprising means responsive to the actuation of said first means for energizing and de-energizing said motor to remove and apply inhibit signals to said terminals.

Claim 18

In a motor control system, control means for starting and stopping a motor comprising first means actuatable between first and second states to energize and de-energize the motor, second means for sensing a condition of said motor, third means responsive to said second means for inhibiting said first means from being actuated from one state to another state until the cessation of said condition, means for providing a speed command signal for said motor, speed control means responsive to said signal for controlling the conduction of current to said motor in response to said command signal, control circuitry means responsive to the actuation of said first means to its state for energizing said motor to effect connection of said speed command signal to said speed responsive means, a power converter for supplying rectified alternating current power to said motor in response to said speed command signal and a second power converter for transmitting power from said motor when the motor is operating in a regenerative mode, said first and second power converters including inhibit terminals for receiving an inhibit signal which inhibits operation of the power converters, said control means comprising means responsive to the actuation of said first means for energizing and de-energizing said motor to remove and apply inhibit signals to said terminals.

Claim 19

In a motor control system, control means for starting and stopping a motor comprising first means actuatable between first and second states to energize and de-energize the motor, second means for sensing a condition of said motor, third means responsive to said second means for inhibiting said first means from being actuated from one state to another state until the cessation of said condition, means for providing a speed command signal for said motor, speed control means responsive to said signal for controlling the conduction of current to said motor in response to said command signal, control circuitry means responsive to the actuation of said first means to its state for energizing said motor to effect connection of said speed command signal to said speed responsive means, a power converter for supplying rectified alternating current power to said motor in response to said speed command signal and a second power converter for transmitting power from said motor when the motor is operating in a regenerative mode, said first and second power converters including inhibit terminals for receiving an inhibit signal which inhibits operation of the power converters, said control means comprising means responsive to the actuation of said first means for energizing and de-energizing said motor to remove and apply inhibit signals to said terminals.

Claim 20

A motor control system as described in claim 11 wherein said system includes a power converter comprising a controllable rectifying bridge for conducting unidirectional current to drive said motor in accordance with said speed command signal, said power Converter including an inhibit terminal for receiving an inhibit signal for inhibiting operation of the converter and said control means comprises means responsive to the actuation of said first means for effecting the operation of said contactor to remove and apply said inhibit signal.

Claim 21

In a motor control system for a motor including a circuit for conducting motor current to effect the electrical operation of said motor, a contactor having contacts in said circuit for making and breaking the circuit to the motor on the starting and stopping of the motor, a control means actuatable to initiate and stop the electrical operation of the motor, first means actuated to first and second states in response to said control means to actuate said contactor to respectively make and break said circuit on the starting and stopping of the motor, sensing means for sensing the armature current of said motor and for sensing the counter-electromotive force of said motor, and third means responsive to said second means for inhibiting actuation of said first means to start operation of said motor in the presence of a counter-electromotive force and to inhibit operation of said first means to stop said motor in response to the presence of armature current.

Claim 22

In a motor control system for a motor including a circuit for conducting motor current to effect the electrical operation of said motor, a contactor having contacts in said circuit for making and breaking the circuit to the motor on the starting and stopping of the motor, a control means actuatable to initiate and stop the electrical operation of the motor, first means actuated to first and second states in response to said control means to actuate said contactor to respectively make and break said circuit on the starting and stopping of the motor, sensing means for sensing the armature current of said motor and for sensing the counter-electromotive force of said motor, and third means responsive to said second means for inhibiting actuation of said first means to start operation of said motor in the presence of a counter-electromotive force and to inhibit operation of said first means to stop said motor in response to the presence of armature current.