Abstract

A system for reducing inrush loading when a source power is restored includes a device for switching power that selectively connects a load to the source of power and a circuit for measuring the AC voltage at the source and for determining when the AC voltage is within operating range. Responsive to the AC voltage being within operating range, the system delays for a time period then connects the load to the source of power by way of the device for switching power.

IPC Classes  ?

• H02P 1/24 - Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual AC commutator motor
• H02P 1/02 - Arrangements for starting electric motors or dynamo-electric converters Details
• H02P 1/42 - Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual single-phase induction motor
• H02P 23/02 - Arrangements or methods for the control of AC motors characterised by a control method other than vector control specially adapted for optimising the efficiency at low load
• H02P 23/08 - Controlling based on slip frequency, e.g. adding slip frequency and speed proportional frequency
• H02P 23/26 - Power factor control [PFC]
• G05B 19/042 - Programme control other than numerical control, i.e. in sequence controllers or logic controllers using digital processors
• H02H 7/09 - Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors against over-voltageEmergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors against reduction of voltageEmergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for dynamo-electric motors against phase interruption
• H02H 11/00 - Emergency protective circuit arrangements for preventing the switching-on in case an undesired electric working condition might result

Abstract

A system for controlling power from an AC voltage to an induction motor to reduce surge when power is restored to a power grid is disclosed including, a device for switching power to the induction motor that has a trigger controllable to enable the device to provide a variable amount of power to the induction motor. The system includes a second device for measuring the AC voltage at the source to determine when power is available, hence determining when the AC voltage is within operating range. Responsive to the AC voltage coming within operating range, the system delays for a time period then initiates power to the induction motor by controlling the device for switching power.

IPC Classes  ?

• H02P 1/42 - Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual single-phase induction motor
• H02P 1/02 - Arrangements for starting electric motors or dynamo-electric converters Details
• H02P 23/02 - Arrangements or methods for the control of AC motors characterised by a control method other than vector control specially adapted for optimising the efficiency at low load
• H02P 23/08 - Controlling based on slip frequency, e.g. adding slip frequency and speed proportional frequency

Abstract

A device for improving efficiency of an induction motor soft-starts the motor by applying a power to the motor that is substantially less than the rated power of the motor then gradually increasing the power while monitoring changes in current drawn by the motor, thereby detecting when maximum efficiency is found. Once maximum efficiency is found, the nominal motor current is found and operating ranges are set. Now, the phase angle between the voltage and the current to the motor is measured and power to the motor is increasing when the phase angle is less than a minimum phase angle (determined during soft-start) and power to the motor is decreased when the phase angle is greater than or equal to the minimum phase angle as long as the voltage does not fall below a minimum voltage determined during soft-start.

IPC Classes  ?

• H02P 23/02 - Arrangements or methods for the control of AC motors characterised by a control method other than vector control specially adapted for optimising the efficiency at low load

Abstract

A device for improving efficiency of an induction motor soft-starts the motor by applying a power to the motor that is substantially less than the rated power of the motor then gradually increasing the power while monitoring changes in current drawn by the motor, thereby detecting when maximum efficiency is found. Once maximum efficiency is found, the nominal motor current is found and operating ranges are set. Now, the phase angle between the voltage and the current to the motor is measured and power to the motor is increasing when the phase angle is less than a minimum phase angle (determined during soft-start) and power to the motor is decreased when the phase angle is greater than or equal to the minimum phase angle as long as the voltage does not fall below a minimum voltage determined during soft-start.

IPC Classes  ?

• H02P 1/26 - Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual polyphase induction motor
• H02P 1/42 - Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual single-phase induction motor

Abstract

A device for improving efficiency of an induction motor that soft-starts the motor by applying a voltage to the motor that is substantially less than the rated voltage then gradually increasing the voltage while monitoring changes in current drawn by the motor, thereby detecting when maximum efficiency is found. Once maximum efficiency is found, the nominal motor current is found and operating ranges are set. Now, the voltage to the motor is increased/decreased by measuring the phase angle between the voltage and the current to the motor and increasing the voltage when the phase angle is less than a minimum phase angle (determined during soft-start) and decreasing the voltage when the phase angle is greater than or equal to the minimum phase angle as long as the voltage does not fall below a minimum voltage determined during soft-start.

IPC Classes  ?

• H02P 1/42 - Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual single-phase induction motor
• H02P 3/18 - Arrangements for stopping or slowing electric motors, generators, or dynamo-electric converters for stopping or slowing an individual dynamo-electric motor or dynamo-electric converter for stopping or slowing an AC motor

Abstract

A device for improving efficiency of an induction motor that soft-starts the motor by applying a voltage to the motor that is substantially less than the rated voltage then gradually increasing the voltage while monitoring changes in current drawn by the motor, thereby detecting when maximum efficiency is found. Once maximum efficiency is found, the nominal motor current is found and operating ranges are set. Now, the voltage to the motor is increased/decreased by measuring the phase angle between the voltage and the current to the motor and increasing the voltage when the phase angle is less than a minimum phase angle (determined during soft-start) and decreasing the voltage when the phase angle is greater than or equal to the minimum phase angle as long as the voltage does not fall below a minimum voltage determined during soft-start.

IPC Classes  ?

• H02P 1/28 - Arrangements for starting electric motors or dynamo-electric converters for starting dynamo-electric motors or dynamo-electric converters for starting an individual polyphase induction motor by progressive increase of voltage applied to primary circuit of motor
• H02P 8/02 - Arrangements for controlling dynamo-electric motors rotating step by step specially adapted for single-phase or bi-pole stepper motors, e.g. watch-motors, clock-motors
• H02P 23/02 - Arrangements or methods for the control of AC motors characterised by a control method other than vector control specially adapted for optimising the efficiency at low load
• H02P 25/04 - Single phase motors, e.g. capacitor motors