A modular structure supports elevated rail segments for delivering electrical power to a moving work machine, such as a hauler at a mining site. Opposite ends of a roadside barrier contain complementary tubular couplers arranged vertically. A lower end of a dielectric post positioned in one of the tubular couplers has opposing dielectric plates at an upper end. A top edge of each plate has a creepage concavity between a pair of rail recesses. Another dielectric post of similar configuration is positioned in the other of the tubular couplers. Holes within the couplers and the posts ensure alignment of respective rail recesses in which conductive rails are placed. Dielectric inserts frictionally lock the rails into the rail recesses.

A modular structure supports elevated rail segments for delivering electrical power to a moving work machine, such as a hauler at a mining site. Opposite ends of a roadside barrier contain complementary tubular couplers arranged vertically. A lower end of a dielectric post positioned in one of the tubular couplers has opposing dielectric plates at an upper end. A top edge of each plate has a creepage concavity between a pair of rail recesses. Another dielectric post of similar configuration is positioned in the other of the tubular couplers. Holes within the couplers and the posts ensure alignment of respective rail recesses in which conductive rails are placed. Dielectric inserts frictionally lock the rails into the rail recesses.

A work machine, such as a hauler at a mining site, includes a conductor rod housing concentric metal tubes for receiving electrical power from a contactor sliding on a power rail. A connection assembly includes lugs branching orthogonally from respective ones of the concentric metal tubes to an exterior of the conductor rod. The lugs include ball-and-socket joints configured to enable semi-spherical movement of the lugs at the exterior with respect to the joints. When attached to the contactor via conductive arms, the connection assembly provides multiple degrees of freedom for the conductor rod relative to the contactor and avoids detachment of the contactor from the power rail.

A power conversion system includes an AC to DC conversion circuit, a voltage detector, a step-down chopper circuit, a power conversion device for auxiliary power sources, and a control unit. The AC to DC conversion circuit converts AC power supplied from overhead wires via a transformer into DC power. The voltage detector detects a voltage of AC power supplied from the transformer. The step-down chopper circuit steps down the voltage of DC power produced through conversion by the AC to DC conversion circuit. The power conversion device for auxiliary power sources converts the DC power stepped down by the step-down chopper circuit into power for driving loads mounted in an electric vehicle and supplies it to the loads. The control unit controls the AC to DC conversion circuit and the step-down chopper circuit such that the voltage of AC power detected by the voltage detector approaches a reference voltage.

A controller of an AC electric vehicle includes a first specific-frequency-current computation unit that extracts a current component corresponding to a first specific frequency set value from a main-transformer output current and outputs the current component as a first specific-frequency current, a subtractor that subtracts the first specific-frequency current from the main-transformer output current and outputs a subtraction result as a current deviation, a second specific-frequency-current computation unit that extracts a current component corresponding to a second specific frequency set value from the current deviation and outputs the current component as a second specific-frequency current, and a power-failure detection unit that compares the second specific-frequency current with a predetermined power-failure detection-current set value and outputs a power-failure detection signal when the second specific-frequency current is larger than the power-failure detection-current set value.

If a vehicle speed is less than a predetermined value when a hybrid control mode is a series mode and a charge mode is selected (S10-S14), it is determined whether an SOC of a high voltage battery is less than a predetermined value or not (S16), and when the SOC of the high voltage battery is less than the predetermined value, ignition timing is corrected to be retarded (S18).

A control device for electric motor vehicle configured to decelerate by a regenerative braking force of the motor detects an accelerator operation amount, calculates a motor torque command value and controls the motor on the basis of the calculated motor torque command value. Further, a speed parameter proportional to a traveling speed is detected, and a feedback torque for stopping the electric motor vehicle is calculated on the basis of the detected speed parameter. Furthermore, the speed parameter is estimated in accordance with a state of the electric motor vehicle, and a feedforward torque is calculated on the basis of the estimated speed parameter. When accelerator operation amount is not larger than a predetermined value and the electric motor vehicle stops shortly, the motor torque command value is converged to zero on the basis of the feedback torque and the feedforward torque with a reduction in the traveling speed.

A fleet and trolley system, a first method of charging a work machine, and a second method of charging a fleet of work machines are disclosed. The fleet and trolley system includes a trolley network, at least one zero-emission work machine, and a controller. The controller manages a scheduled usage of the trolley network, a power draw, and a distribution of the power draw by the work machine. The first method includes monitoring states of the work machine, scheduling a usage of the trolley network, and supplying electric power to the work machine. The second method includes monitoring states of a fleet, monitoring states of the trolley network, scheduling usages of the trolley network, and supplying electric power to one or more machines of the fleet. Advantageously, the disclosed system and methods may improve an efficiency, productivity, and longevity of a fleet of zero-emission work machines.

A fleet and trolley system, a first method of charging a work machine, and a second method of charging a fleet of work machines are disclosed. The fleet and trolley system includes a trolley network, at least one zero-emission work machine, and a controller. The controller manages a scheduled usage of the trolley network, a power draw, and a distribution of the power draw by the work machine. The first method includes monitoring states of the work machine, scheduling a usage of the trolley network, and supplying electric power to the work machine. The second method includes monitoring states of a fleet, monitoring states of the trolley network, scheduling usages of the trolley network, and supplying electric power to one or more machines of the fleet. Advantageously, the disclosed system and methods may improve an efficiency, productivity, and longevity of a fleet of zero-emission work machines.

A suspension characteristic is changed depending on a travel state by a simple structure. An ECU uses a vehicle speed-spring constant setting part to calculate a target spring constant depending on a vehicle speed, and uses a spring constant-frequency setting part to calculate a set frequency corresponding to the target spring constant. An oscillation input calculation part generates a signal representing an oscillation input oscillating at the set frequency. A superimposition part sets a value acquired by superimposing the oscillation input on a target driving force to a new target driving force. As a result, the wheel exhibits a minute oscillation in a longitudinal direction, resulting in an input of the minute oscillation to a suspension bush. The suspension bush changes in a spring constant and a damping coefficient depending on the frequency of the input minute oscillation. As a result, the suspension characteristic can be changed.