A current limiting method of a fuel cell stack is capable of preventing current of the fuel cell stack from rapidly dropping to prevent jerking or shock from occurring while a vehicle travels. The method includes: determining whether performance deterioration of a unit cell of the fuel cell stack has occurred, employing a feed forward control type current limiting logic of the fuel cell stack before an output of the fuel cell vehicle is lowered, decreasing the current of the fuel cell stack to a predetermined level by the feed forward control type current limiting logic, and gradually restoring the current of the fuel cell stack to a maximum current usage value from a point in time when the current of a load is used.

An electric vehicle includes an electric motor for transmitting torque to a wheel, a clutch pedal operated by driver, and a torque controller for controlling torque of the electric motor. The torque controller is configured to control torque of the electric motor in response to an operation amount of the clutch pedal. The electric vehicle may include a shift lever for selecting a mode of any one of a plurality of modes in which torque characteristics of the electric motor differ in stages with respect to a rotational speed of the electric motor. The clutch pedal is operated when the shift lever is operated. The torque controller is configured to control torque of the electric motor in response to the mode selected by the shift lever.

A motor-driving control system includes an actuator configured to generate rotational force by driving received current, a current provider configured to provide current to the actuator while repeatedly turning on and off the current at a preset period and duty, and a controller configured to estimate a rotation position or a rotation speed of the actuator in a section in which the current of the current provider is turned on or off and to control the current provider to follow a speed command based on the estimated rotation position or rotation speed.

A motor-driving control system includes an actuator configured to generate rotational force by driving received current, a current provider configured to provide current to the actuator while repeatedly turning on and off the current at a preset period and duty, and a controller configured to estimate a rotation position or a rotation speed of the actuator in a section in which the current of the current provider is turned on or off and to control the current provider to follow a speed command based on the estimated rotation position or rotation speed.

A motor device for a vehicle includes a stator, a rotor, a bearing, an inverter, and a controller. The stator is attached into a housing and includes a concentrated winding coil. The rotor includes a permanent magnet. The bearing supports a rotating shaft of the rotor. The inverter controls an energization state of the concentrated winding coil. If a rotational speed of the rotor is greater than a threshold, the controller outputs a control signal to the inverter to execute field weakening control, and thereby makes a potential difference between the housing and the rotating shaft lower than a withstand voltage of the bearing. The control signal controls the energization state of the concentrated winding coil. The field weakening control generates magnetic flux of the concentrated winding coil in a direction of weakening magnetic flux of the permanent magnet.

A motor device for a vehicle includes a stator, a rotor, a bearing, an inverter, and a controller. The stator is attached into a housing and includes a concentrated winding coil. The rotor includes a permanent magnet. The bearing supports a rotating shaft of the rotor. The inverter controls an energization state of the concentrated winding coil. If a rotational speed of the rotor is greater than a threshold, the controller outputs a control signal to the inverter to execute field weakening control, and thereby makes a potential difference between the housing and the rotating shaft lower than a withstand voltage of the bearing. The control signal controls the energization state of the concentrated winding coil. The field weakening control generates magnetic flux of the concentrated winding coil in a direction of weakening magnetic flux of the permanent magnet.

The invention relates to a method for operating a motor vehicle (1) which has an electrical machine (7) with at least three phases, an electrical energy store (13) and a power electronics system (12) having a plurality of switching elements, wherein the switching elements of the power electronics system (12) are actuated for electrically connecting the phases to the energy store (13), in order to produce a generator deceleration moment. Provision is made for a driving situation of the motor vehicle (1) to be determined, wherein an actuation method is selected from amongst a group of at least two possible actuation methods according to the determined driving situation, and wherein the switching elements are actuated according to the selected actuation method.

A drive system comprises a DC-DC converter that is arranged to receive an input voltage from a battery having a nominal battery voltage. The DC-DC converter has a first mode of operation in which the DC-DC converter generates a regulated output voltage from the input voltage and supplies the regulated output voltage to a load, and a second mode of operation in which the DC-DC converter is by-passed such that the input voltage from the battery is supplied to the load. A controller is arranged to compare the input voltage to a threshold voltage that is less than the nominal battery voltage. The controller operates the DC-DC converter in the first mode when the input voltage is less than the threshold voltage, and operates the DC-DC converter otherwise.

A drive system comprises a DC-DC converter that is arranged to receive an input voltage from a battery having a nominal battery voltage. The DC-DC converter has a first mode of operation in which the DC-DC converter generates a regulated output voltage from the input voltage and supplies the regulated output voltage to a load, and a second mode of operation in which the DC-DC converter is by-passed such that the input voltage from the battery is supplied to the load. A controller is arranged to compare the input voltage to a threshold voltage that is less than the nominal battery voltage. The controller operates the DC-DC converter in the first mode when the input voltage is less than the threshold voltage, and operates the DC-DC converter otherwise.

A method for controlling an electric hand truck includes determining whether user manipulation is present due to a user input on the electric hand truck; and, if there is no user manipulation, then braking an electric motor that drives the wheels of the electric moving vehicle in a softlock manner in which, instead of power being applied to the electric motor, electrodes of the electric motor are short-circuited.