The present invention relates to a battery arrangement for an electrically powered industrial vehicle. The battery arrangement comprises a battery and ancillary equipment arranged to connect the battery to the vehicle. The battery is removably connected to the vehicle and comprises a current sensor. The battery is in a first state (A) when a measured current out from the battery exceeds a predetermined first current level. In the first state (A) the battery is prevented from turning power off to the vehicle. The battery is in a second state (B) when a measured current out from the battery is below a predetermined first current level for a predetermined first period of time. In the second state (B) the battery is allowed to turn power off to the vehicle.

The present invention relates to a battery arrangement for an electrically powered industrial vehicle. The battery arrangement comprises a battery and ancillary equipment arranged to connect the battery to the vehicle. The battery is removably connected to the vehicle and comprises a current sensor. The battery is in a first state (A) when a measured current out from the battery exceeds a predetermined first current level. In the first state (A) the battery is prevented from turning power off to the vehicle. The battery is in a second state (B) when a measured current out from the battery is below a predetermined first current level for a predetermined first period of time. In the second state (B) the battery is allowed to turn power off to the vehicle.

A control apparatus includes: a rotor temperature estimation unit estimating a temperature of a rotor based on stator temperature information from a first temperature sensor for identifying a temperature of a stator, refrigerant temperature information from a second temperature sensor for identifying a temperature of refrigerant used to cool an electric motor, and rotation speed information about the rotor from a resolver for identifying a rotation speed of the rotor; and an electric motor control unit controlling at least one of an output characteristic and a drive condition of the electric motor based on the temperature of the rotor estimated by the rotor temperature estimation unit.

When providing alternating current (AC) power to operate AC powered devices such as power tools (such as drills, table saws, miter saws), equipment (such as lawn mowers), and consumer products (such as refrigerators, television, lights) without being tied to a fixed utility power supply typically requires a generator (such as an internal combustion engine based generator) or a battery powered inverter. In order to meet power and runtime needs for these devices, a battery powered inverter must be relatively large and expensive. This simple fact prohibits their use in many environments.

When providing alternating current (AC) power to operate AC powered devices such as power tools (such as drills, table saws, miter saws), equipment (such as lawn mowers), and consumer products (such as refrigerators, television, lights) without being tied to a fixed utility power supply typically requires a generator (such as an internal combustion engine based generator) or a battery powered inverter. In order to meet power and runtime needs for these devices, a battery powered inverter must be relatively large and expensive. This simple fact prohibits their use in many environments.

A battery-powered motor may include an electric motor, a controller, and a housing. The electric motor may be wound to enable the battery-powered motor to achieve a non-limited motor maximum motor revolutions per minute (RPM) for at least one specified battery. The controlling current may include limiting current to the electric motor at lower RPMs, and limiting the current to prevent the RPM of the electric motor from exceeding a limited maximum motor RPM which is lower than the non-limited motor maximum RPM. The housing may enclose the electric motor and the controller and the specified battery. The housing may have a form factor to engage with a machine that engages with an internal combustion engine that has a maximum engine RPM that is approximately the same as the limited maximum motor RPM.

A battery-powered motor may include an electric motor, a controller, and a housing. The electric motor may be wound to enable the battery-powered motor to achieve a non-limited motor maximum motor revolutions per minute (RPM) for at least one specified battery. The controlling current may include limiting current to the electric motor at lower RPMs, and limiting the current to prevent the RPM of the electric motor from exceeding a limited maximum motor RPM which is lower than the non-limited motor maximum RPM. The housing may enclose the electric motor and the controller and the specified battery. The housing may have a form factor to engage with a machine that engages with an internal combustion engine that has a maximum engine RPM that is approximately the same as the limited maximum motor RPM.

A system includes a converter for powering a synchronous electric machine to which it is connected by cables, an insulating device and a mechanism for short-circuiting phases of the machine. The system includes primary detectors for detecting an overcurrent in the converter and a securing device able to open the insulating device when receiving a primary detection signal emitted by the primary detector. The system also includes secondary detectors able to detect a short-circuit downstream from the insulating device and to emit a secondary detection signal toward the securing device, the latter actuating the closing of the mechanism for short-circuiting as long as they have already received a primary detection signal having led to the opening of the insulating device.

A method for controlling an electric motor is described herein. The method comprises setting a current limit, a speed limit and a torque limit. The method also comprises sensing a DC link current, comparing the sensed DC link current with the current limit and adjusting the torque limit based on the comparison with the current limit to provide an adjusted torque limit. The method also comprises sensing the speed of the electric motor, comparing the speed with the speed limit and further adjusting the adjusted torque limit based on the comparison with the speed limit.

A method for controlling an electric motor is described herein. The method comprises setting a current limit, a speed limit and a torque limit. The method also comprises sensing a DC link current, comparing the sensed DC link current with the current limit and adjusting the torque limit based on the comparison with the current limit to provide an adjusted torque limit. The method also comprises sensing the speed of the electric motor, comparing the speed with the speed limit and further adjusting the adjusted torque limit based on the comparison with the speed limit.