Siemens Industry, Inc.

Siemens Aktiengesellschaft

Caterpillar Global Mining LLC

Joy Mazumdar

Walter Köllner

Ekkehard Pittius

Michael G Onsager

Walter Koellner

Andreas Holweck

Daniel W Robertson

Ken Furem

Walter G Koellner

A mining haul truck driven by electrical wheel motors is operated with all electrical power sources; that is, without a diesel engine. While travelling on the loading site, the mining haul truck is powered by an on-board energy storage system, which can comprise a bank of ultracapacitors. The mining haul truck then moves to the bottom of a trolley ramp and is coupled to trolley lines. While travelling uphill, the mining haul truck is powered by the trolley lines, and the on-board energy storage system is charged by the trolley lines. When the mining haul truck reaches the top of the trolley ramp, the mining haul truck is uncoupled from the trolley lines. While travelling on the unloading site, the mining haul truck is powered by the on-board energy storage system. The on-board energy storage system can also be charged by retard energy generated by the wheel motors during braking.

System and method for all electrical operation of a mining haul truck

A method for operating an ultracapacitor system used in a mining excavator powered by an power source. The method includes detecting whether a power from the power source is present. Next, a voltage level of the ultracapacitor system is measured if the power is not present. The measured voltage level is then compared with a minimum voltage level for the ultracapacitor system. If the measured voltage level is more than the minimum voltage level, auxiliary power is supplied from the ultracapacitor system to operate mining excavator systems. The auxiliary power may be used to power electronic systems and components such as computers, displays, control systems, gas insulated switchgear and lighting systems.

System and method for providing auxiliary power by regeneration power management in mobile mining equipment

Braking current generated by an electrical motor on mining equipment during a retard interval is switched through one or more grid resistors that are liquid cooled. Under low ambient temperatures, a heating current can be switched through the grid resistors when the electrical motor is not operating in a retard interval. An integrated cooling system can be used to cool grid resistors and power modules. Heat dissipated by the grid resistors and the power modules can be circulated through auxiliary heating loops to heat portions of the mining equipment under low ambient temperatures. Multiple liquid-cooled power modules, liquid-cooled grid resistors, auxiliary heating loops, control modules, radiators, and pumps can be coupled by a liquid distribution system with various combinations of parallel and serial branches. Temperature, pressure, and flow rate in each branch can be independently controlled. Operation of the integrated cooling system can be controlled by a computational system.

Dissipation of the braking energy of electrically powered mining equipment by liquid-cooled braking resistors

High-power synchronous motors are commonly used in mining operations, for example, in gearless draglines, gearless conveyor drives, and gearless mill drives. Substantial electromagnetic energy is stored in the inductive field windings. In the event of a system fault, such as a short in the direct current power source exciting the field windings, the electromagnetic energy needs to be discharged from the field windings. This electromagnetic energy is typically dissipated as waste heat through a resistor. Disclosed is a field discharge system in which the electromagnetic energy is captured and stored as electrical energy in a capacitor. If an ultracapacitor bank is used for storage, the charged ultracapacitor bank can be used as a backup or auxiliary power source for mining operations. The discharge time is sufficiently small that high speed circuit breakers are not needed to disconnect stator windings from the alternating current power source when a fault occurs.

System and method for fast discharge of a ring motor field

A method for operating an ultracapacitor system used in a mining excavator powered by an electrical power source. The method includes the step of detecting whether a line power from the electrical power source is present. Next, a voltage level of the ultracapacitor system is measured if the line power is not present. The measured voltage level is then compared with a minimum voltage level for the ultracapacitor system. If the measured voltage level is more than the minimum voltage level, auxiliary power is supplied from the ultracapacitor system to operate mining excavator systems. The auxiliary power may be used to power electronic systems and components such as computers, displays, control systems, gas insulated switchgear and lighting systems.

Retard energy regenerated from an electrical motor during braking action is reinjected into a power system via trolley lines. The retard energy may be transmitted to a bidirectional electric substation and returned to a utility grid. The retard energy may also be transmitted to an auxiliary energy storage system, such as an ultracapacitor system or a battery system. Installing trolley lines for mining haul trucks on a downhill slope may be used to capture and re-use substantial quantities of retard energy.

System and method for reinjection of retard energy in a trolley-based electric mining haul truck

The maximum electrical power drawn from an electrical power source by a mining excavator comprising electric motors is reduced by supplying supplementary electrical power from an electrical energy storage unit. The input electrical power drawn by the mining excavator is cyclic. An upper limit is set for the electrical power drawn from the electrical power source. When the input electrical power drawn by the mining excavator exceeds the upper limit, electrical power is supplied by the electrical energy storage unit, such as an ultracapacitor bank. The ultracapacitor bank may be charged by the electrical power source during off-peak intervals. Electrical power generated by electrical motors operating in a regeneration interval may also be recaptured and stored in the electrical energy storage unit.

Limiting peak electrical power drawn by mining excavators

A mining haul truck driven by electrical wheel motors is powered by a trolley power system during an uphill climb. Retard energy captured during braking action on either the uphill climb or downhill descent is stored by an on-board electrical energy storage system. Electrical power is supplied from the on-board electrical energy storage system to reduce the peak power demand on the trolley power system during the uphill climb. One implementation of the on-board electrical energy storage system uses an ultracapacitor system.

Peak demand reduction in mining haul trucks utilizing an on-board energy storage system

An excavator drive system wherein one of a pair of propulsion motors shares one of a pair of inverter power sources with another of a pair of motors dedicated to crowd and hoist motions. A pair of non-volatile bi-state switches, triggered under control of a controller, allow sharing of inverters between hoist and propelmotors. Another pair of switches allows inverter sharing between propeland crowd motors. Each pair of switches enables change over and power transfer from one of the paired motors to the other motor. The bi-state switches enable quicker transfer of power between motors than transfer switches employing external motor-powered mechanical transfer linkages. Bi-state transfer switches also maintain transfer coupling status in the event of power failure to the switch actuators, allowing an excavator operator to continue the drive function in operation prior to the switch power failure.

Excavator drive system with bi state motor transfer switches

Certain exemplary embodiments can provide a system, which can comprise a bucket excavation controller. The bucket excavation controller can be adapted to control one or more digging functions of a mining excavator. For example, the bucket excavation controller can be adapted to automatically control a crowd motion of the mining excavator.

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Norcross, GA, United States of America

Joy Mazumdar