Simplified topology for trolley assist-capable electric drive truck
First Claim
1. A trolley assist-capable electric drive truck comprising:
- a frame;
a plurality of ground engaging elements coupled to the frame;
an onboard electrical power source attached to the frame and including an internal combustion engine mechanically coupled to an electrical power generator;
at least one electric propulsion motor coupled to the ground engaging elements;
a circuit electrically connecting the electrical power generator to the electric propulsion motor;
a pantograph supported on the frame and movable between a trolley line engagement configuration and a stowed configuration;
a DC link that electrically connects the circuit to the pantograph, and including a first contactor electrically separating a positive direct current conductor from a positive pantograph conductor;
a second contactor electrically separating a negative direct current conductor from a negative pantograph conductor;
the positive direct current conductor being electrically separated from the negative direct current conductor by the first contactor, a third contactor, a grid resistor and the second contactor; and
each of the first, second and third contactors being changeable between an open circuit configuration and a closed circuit configuration.
1 Assignment
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Accused Products
Abstract
A trolley assist-capable electric drive truck includes a DC link with first, second and third contactors that may be opened and closed in different configurations to operate the truck in different modes. In a normal propel mode, the three contactors are open and electrical power is routed from an onboard electrical power source to electric propulsion motors. During normal retard mode, the three contactors are closed to route electrical energy generated by the electric propulsion motors through a grid resistor of the DC link. In a trolley mode, the first and second contactors are closed, but the third contactor is open, and electrical power is routed from the trolley lines to the motors for propulsion, or in a reverse direction for retarding the truck.
12 Citations
11 Claims
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1. A trolley assist-capable electric drive truck comprising:
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a frame; a plurality of ground engaging elements coupled to the frame; an onboard electrical power source attached to the frame and including an internal combustion engine mechanically coupled to an electrical power generator; at least one electric propulsion motor coupled to the ground engaging elements; a circuit electrically connecting the electrical power generator to the electric propulsion motor; a pantograph supported on the frame and movable between a trolley line engagement configuration and a stowed configuration; a DC link that electrically connects the circuit to the pantograph, and including a first contactor electrically separating a positive direct current conductor from a positive pantograph conductor;
a second contactor electrically separating a negative direct current conductor from a negative pantograph conductor;
the positive direct current conductor being electrically separated from the negative direct current conductor by the first contactor, a third contactor, a grid resistor and the second contactor; and
each of the first, second and third contactors being changeable between an open circuit configuration and a closed circuit configuration. - View Dependent Claims (2, 3, 4, 5)
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6. A DC link of a trolley assist-capable electric drive truck, comprising:
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a first contactor electrically separating a positive direct current conductor from a positive pantograph conductor, a second contactor electrically separating a negative direct current conductor from a negative pantograph conductor, the positive direct current conductor being electrically separated from the negative direct current conductor by the first contactor, a third contactor, a grid resistor and the second contactor; and each of the first, second and third contactors being changeable between an open circuit configuration and a closed circuit configuration.
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7. A method of operating a trolley assist-capable electric drive truck that includes a plurality of ground engaging elements coupled to a frame;
- an onboard electrical power source attached to the frame and including an internal combustion engine mechanically coupled to an electrical power generator;
at least one electric propulsion motor coupled to the ground engaging elements;
a circuit electrically connecting the electrical power generator to the electric propulsion motor;
a pantograph supported on the frame and movable between a trolley line engagement configuration and a stowed configuration; and
a DC link that electrically connects the circuit to the pantograph, and including first contactor electrically separating a positive direct current conductor from a positive pantograph conductor;
a second contactor electrically separating a negative direct current conductor from a negative pantograph conductor;
the positive direct current conductor being electrically separated from the negative direct current conductor by the first contactor, a third contactor, a grid resistor and the second contactor; and
each of the first, second and third contactors being changeable between an open circuit configuration and a closed circuit configuration, the method comprising the steps of;propelling the truck in a normal propel mode by opening the first, second and third contactor of the DC link and routing electrical energy from the onboard electrical power source to the electric propulsion motor coupled to the ground engaging elements; propelling the truck in a trolley propel mode by closing the first and second contactors and opening the third contactor and routing electrical energy from a pantograph through the DC link to the electric propulsion motor; and retarding the truck in a normal retard mode by closing all of the first, second and third contactors and routing electrical energy from the electric propulsion motor through a grid resistor of the DC link. - View Dependent Claims (8, 9, 10, 11)
- an onboard electrical power source attached to the frame and including an internal combustion engine mechanically coupled to an electrical power generator;
Specification