An electric system of an electromechanical power transmission chain is provided that includes a first capacitive circuit, converter equipment between the first capacitive circuit and an electric machine, a second capacitive circuit, and a direct voltage converter between the first and second capacitive circuits. The electromechanical power transmission chain is a parallel transmission chain where the electric machine is mechanically connected to a combustion engine and to one or more actuators. The electric system includes a control system for controlling the direct voltage converter in response to changes in a first direct voltage of the first capacitive circuit and for controlling the converter equipment in response to changes in a second direct voltage of the second capacitive circuit. The first direct voltage is kept on a predetermined voltage range whereas the second direct voltage is allowed to fluctuate in order to respond to peak power needs.

A power converter (10) for operating a first electric machine (12) and a second electric machine (14), comprising: a first converter element (16), a second converter element (18) and a first terminal connection (21), a second terminal connection (22) and a third terminal connection (23) for connecting the power converter (10) to a three-phase energy supply (60), wherein
the first converter element (16) comprises a first rectifier circuit (31) and a second rectifier circuit (32), the second converter element (18) comprises a third rectifier circuit (33), wherein
the first rectifier circuit (31) has a first AC-side pole (51) and a second AC-side pole (52), the second rectifier circuit (32) has a third AC-side pole (53) and a fourth AC-side pole (54) and the third rectifier circuit (33) has a fifth AC-side pole (55) and a sixth AC-side pole (56),
the first rectifier circuit (31) and the second rectifier circuit (32) are connected in parallel on the DC-voltage side and are connected to a common first DC-voltage-side pole (41) and a common second DC-voltage-side pole (42), wherein
the third rectifier circuit (33) is connected on the DC-voltage side to a third DC-voltage-side pole (43) and a fourth DC-voltage-side pole (44), wherein
the first DC-voltage-side pole (41) is at least connectable to the third DC-voltage-side pole (43) by means of a first current path (36) and
the second DC-voltage-side pole (42) is at least connectable to the fourth DC-voltage-side pole (44) by means of a second current path (37), wherein
at least the first current path (36) or the second current path (37) comprises a semiconductor switch (64).

A power converter (10) for operating a first electric machine (12) and a second electric machine (14), comprising: a first converter element (16), a second converter element (18) and a first terminal connection (21), a second terminal connection (22) and a third terminal connection (23) for connecting the power converter (10) to a three-phase energy supply (60), wherein
the first converter element (16) comprises a first rectifier circuit (31) and a second rectifier circuit (32), the second converter element (18) comprises a third rectifier circuit (33), wherein
the first rectifier circuit (31) has a first AC-side pole (51) and a second AC-side pole (52), the second rectifier circuit (32) has a third AC-side pole (53) and a fourth AC-side pole (54) and the third rectifier circuit (33) has a fifth AC-side pole (55) and a sixth AC-side pole (56),
the first rectifier circuit (31) and the second rectifier circuit (32) are connected in parallel on the DC-voltage side and are connected to a common first DC-voltage-side pole (41) and a common second DC-voltage-side pole (42), wherein
the third rectifier circuit (33) is connected on the DC-voltage side to a third DC-voltage-side pole (43) and a fourth DC-voltage-side pole (44), wherein
the first DC-voltage-side pole (41) is at least connectable to the third DC-voltage-side pole (43) by means of a first current path (36) and
the second DC-voltage-side pole (42) is at least connectable to the fourth DC-voltage-side pole (44) by means of a second current path (37), wherein
at least the first current path (36) or the second current path (37) comprises a semiconductor switch (64).

A hybrid vehicle includes an isolation switch disposed between a first bus that is electrically coupled to a starter for an engine and a second bus that is electrically coupled to a power converter and accessory loads. The hybrid vehicle includes a controller programmed to normally command the switch closed, and, in response to expiration of a predetermined time interval without starting the engine, command the switch to open for a predetermined duration to perform diagnostics on the isolation switch.

An improved vehicle propulsion system using a hybrid variable reluctance motor (VRM) system which allows for: diversified power sources for typical roadway vehicles, and gradual fleet and roadway implementation. In one embodiment, all of the components that are required for a typical vehicle to use the hybrid VRM system can be intergraded in a non-obstructive manner into typical vehicle components. In one embodiment, the vehicle operator selectively determines the amount of propulsive energy that comes from the on-board engine and the amount that comes from the VRM system.

A dump truck 100 including: an engine 1; a generator 10 driven by the engine 1; and a pair of driving wheels 3L and 3R arranged to the left and right of a vehicle body frame 7 includes: a traveling electric motor 12L including a plurality of electric motors 12La, 12Lb, and 12Lc that are coupled to the driving wheel 3L and simultaneously drive the driving wheel 3L; and a traveling electric motor 12R including a plurality of electric motors 12Ra, 12Rb, and 12Rc that are coupled to the driving wheel 3R and simultaneously drive the driving wheel 3R. Thereby, drive systems corresponding to loads of dump trucks or the like can be configured using identical components.

A caravanning vehicle system includes a lead vehicle having an engine and at least one trailing vehicle having an electric motor. The at least one trailing vehicle is non-mechanically connected to the lead vehicle. The lead vehicle includes a power transfer system that is configured to transfer electric power, wirelessly, to the at least one trailing vehicle.

A main converter (i) converts AC power from a generator at a primary terminal into DC power at a secondary terminal, an internal combustion engine driving the generator to generate the AC power, or (ii) converts DC power at the secondary terminal into AC power and supplies the AC power to the generator. A first inverter is connected to the secondary terminal of the main converter. A step-down circuit steps down a voltage of the DC power output by the main converter and supplies the stepped-down DC power to a power storage device. The generator, using the power storage device as an electric power source, operates as an electric motor to start the internal combustion engine. After the internal combustion engine is started, the DC power output by the main converter is supplied to the first inverter, stepped down by the step-down circuit, and supplied to the power storage device.

A main converter (i) converts AC power from a generator at a primary terminal into DC power at a secondary terminal, an internal combustion engine driving the generator to generate the AC power, or (ii) converts DC power at the secondary terminal into AC power and supplies the AC power to the generator. A first inverter is connected to the secondary terminal of the main converter. A step-down circuit steps down a voltage of the DC power output by the main converter and supplies the stepped-down DC power to a power storage device. The generator, using the power storage device as an electric power source, operates as an electric motor to start the internal combustion engine. After the internal combustion engine is started, the DC power output by the main converter is supplied to the first inverter, stepped down by the step-down circuit, and supplied to the power storage device.

To provide a technique for reliably acquiring a required braking power during travel and for efficiently using a regenerative power generated during braking. A work vehicle calculates a regenerative power outputted from an electric motor and a target hydraulic driving power for driving a hydraulic pump, supplies the regenerative power to the generator motor operating as a motor and makes the generator motor consume the regenerative power in a case where the regenerative power is equal to or smaller than the target hydraulic driving power, and supplies the regenerative power to the generator motor operating as the motor and makes an exhaust brake consume a power equivalent to a difference between the regenerative power and the target hydraulic driving power in a case where the regenerative power is larger than the target hydraulic driving power.