Work equipment system and control method therefor

A control method for a work equipment system, wherein the work equipment system comprises a motor device providing a motive power to a load device, a temperature sensor measuring a motor temperature of the motor device and a controller comprising a preset temperature, a motor resistance of the motor device, a thermal resistance of the work equipment system and electrical parameters, wherein when the controller receives a required motive power command, the controller performs the control method comprising steps of:

• (a) calculating a first current based on the required motive power command and the electrical parameters;
• (b) calculating a temperature difference between the motor temperature and the preset temperature;
• (c) calculating a thermal power based on the temperature difference and the thermal resistance;
• (d) calculating a second current based on the thermal power and the motor resistance;
• and
• (e) comparing the second current to an effective value of the first current for determining whether the second current is smaller than the first current,
• wherein if the controller identifies that the second current is not smaller than the first current, the controller performs the control method further comprising steps of:
• (f) calculating a current phase difference based on a ratio value of the effective value and the second current;
• (g) calculating a target current phase based on a phase angle of the required motive power command and the current phase difference;
• (h) calculating a target motive power based on the second current, the target current phase and the electrical parameters;
• and
• (i) controlling the motor device to adjust the motive power which is close to the target motive power within an error range.

A work equipment system, comprising:

• a motor device, configured to provide a motive power to a load device;
• a temperature sensor, configured to measure a motor temperature of the motor device;
• a controller, comprising a preset temperature, a motor resistance of the motor device, a thermal resistance of the work equipment system and electrical parameters;
• and
• a cooling device, coupled to the motor device and the controller;
• wherein when the controller receives a required motive power command, the controller is configured to:
• calculate a first current based on the required motive power command and the electrical parameters;
• calculate a temperature difference between the motor temperature and the preset temperature;
• calculate a thermal power based on the temperature difference and the thermal resistance;
• calculate a second current based on the thermal power and the motor resistance;
• and
• compare the second current to an effective value of the first current for determining whether the second current is smaller than the first current;
• wherein when the controller identifies that the second current is smaller than the first current, the controller enables the cooling device,
• wherein when the controller identifies that the second current is not smaller than the first current, the controller disables the cooling device.