Variable speed AC electric drive vehicle
First Claim
Patent Images
1. A self-propelled vehicle comprising:
- a driven ground-engaging means for forcibly acting on the ground to propel the vehicle;
a variable speed AC drive motor on the vehicle drivingly connected to the ground engaging means;
a motor controller having a variable frequency AC output connected to the drive motor;
a switch on the vehicle having first and second inputs, and a switch output connected to the motor controller, the switch having a first position in which the first input is connected to the switch output while the second input is disconnected from the switch output, the switch having a second position in which the second input is connected to the switch output while the first input is disconnected from the switch output;
an electrical conductor for engaging an external power source and for transmitting AC power from the external source to the first input;
an on-board source of AC power mounted on the vehicle and connected to the second input on the switch to provide power to the switch; and
a switch controller operably connected to the switch and the on-board source, the switch controller being operable in response to a control signal to activate the on-board source, and thereafter to shift the switch from the first position to the second position.
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Accused Products
Abstract
An externally powered electric vehicle with an on-board variable speed AC drive motor drawing power from an overhead trolley line. The vehicle may include an auxiliary power source in the form of a battery or internal combustion engine for powering the vehicle when the vehicle is disconnected from the trolley line.
73 Citations
38 Claims
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1. A self-propelled vehicle comprising:
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a driven ground-engaging means for forcibly acting on the ground to propel the vehicle; a variable speed AC drive motor on the vehicle drivingly connected to the ground engaging means; a motor controller having a variable frequency AC output connected to the drive motor; a switch on the vehicle having first and second inputs, and a switch output connected to the motor controller, the switch having a first position in which the first input is connected to the switch output while the second input is disconnected from the switch output, the switch having a second position in which the second input is connected to the switch output while the first input is disconnected from the switch output; an electrical conductor for engaging an external power source and for transmitting AC power from the external source to the first input; an on-board source of AC power mounted on the vehicle and connected to the second input on the switch to provide power to the switch; and a switch controller operably connected to the switch and the on-board source, the switch controller being operable in response to a control signal to activate the on-board source, and thereafter to shift the switch from the first position to the second position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A self-propelled vehicle having a traction device contacting the ground to propel the vehicle, the vehicle comprising;
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an AC drive motor on the vehicle; a power transmission operably connected to the motor and to the traction device for transmitting power to the traction device; an electrical conductor mounted on the vehicle and connectable to an external power source; an on-board source of power mounted on the vehicle; a switch on the vehicle having a first position in which the conductor is electrically connected to the motor and the on-board source is disconnected from the motor, the switch having a second position in which the on-board source is connected to the motor and the conductor is disconnected from the motor; a switch controller operably connected to the switch and to the on-board source, the switch controller being operable in response to a control signal to activate the on-board source, and thereafter to shift the switch from the first position to the second position; and a motor controller connected between the switch and the motor and having a variable frequency AC output. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 24)
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20. A method of operating an electric vehicle having a variable speed AC drive motor, an on-board source of AC power, and a conductor attachable to an external AC power source, the method comprising the steps:
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operating the vehicle with power drawn from the external source through the conductor; sensing a transfer signal; in response to the signal, activating the on-board source of power; sensing the external AC power and the on-board AC power; adjusting the on-board source to synchronize the on-board source with the external source; and after synchronizing, switching to operation of the vehicle with power from the on-board source. - View Dependent Claims (21, 22, 23)
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25. A self-propelled vehicle having a traction device contacting the ground to propel the vehicle, the vehicle comprising:
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an AC drive motor on the vehicle; a power transmission operably connected to the motor and to the traction device for transmitting power to the traction device; an electrical conductor mounted on the vehicle and connectable to an external power source; a switch on the vehicle having a first position in which the conductor is electrically connected to the motor and the on-board source is disconnected from the motor, the switch having a second position in which the on-board source is connected to the motor and the conductor is disconnected from the motor; a switch controller operably connected to the switch and to the on-board source, the switch controller being operable in response to a control signal to activate the on-board source, and thereafter to shift the switch from the first position to the second position; and a motor speed controller connected between the switch and the motor and having a variable frequency AC output, the motor speed controller being operably connected to the switch controller such that the switch controller controls said AC output from the motor controller to the motor. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 38)
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37. A self-propelled vehicle having a traction device contracting the ground to propel the vehicle, the vehicle comprising:
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an AC drive motor on the vehicle; a power transmission operably connected to the motor and to the traction device for transmitting power to the traction device; an electrical conductor mounted on the vehicle and connectable to an external power source; an on-board source of power mounted on the vehicle; a switch on the vehicle having a first position in which the conductor is electrically connected to the motor and the on-board source is disconnected from the motor, the switch having a second position in which the on-board source is connected to the motor and the conductor is disconnected from the motor; first control means for providing variable frequency AC power to the motor; and second control means for automatically, in response to a control signal, activating the on-board source, thereafter shifting the switch from the first position to the second position, and for providing a control signal to the first control means.
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Specification