Patent ID: 8594869

Claim:
A method for controlling a motor of an electrical forklift truck which comprises at least one motor for traveling of the forklift truck or providing power to a pump that supplies power for operating a vehicle or oil to operational devices, a power module for controlling the power supply to the at least one motor, and a control unit for controlling the power module and the motor, the method comprising: determining that a temperature of the motor and/or the power module increases and reaches a predetermined first level temperature value, the predetermined first level temperature value being based on the operating speed of the motor; in response to determining that the temperature reaches the predetermined first level temperature value, using the control unit to decelerate operating speed of the motor to be predetermined first decelerated speed; while the motor is in a state of having been decelerated, determining that the temperature of the motor and/or the power module increases and reaches a predetermined second level temperature value, the predetermined second level temperature value being higher than the first level temperature value and based on the first decelerated speed; and in response to determining that the temperature reaches the predetermined second level temperature value, using the control unit to decelerate the operating speed of the motor to be predetermined second decelerated speed that is lower than the first decelerated speed.