The impact of motor design on overload capacity: The design of high efficiency three-phase asynchronous motor determines its basic overload capacity. From the perspective of winding design, the use of high conductivity copper and the reasonable planning of winding turns and wire diameter can reduce winding resistance and heat generation, thereby maintaining good performance when overloaded. For example, the optimized winding can still run stably for a period of time when the short-term overload current reaches 1.5 times the rated current.
Rotor structure and overload capacity: The rotor structure of the motor is crucial. Deep groove or double squirrel cage rotors, due to their special groove design, can increase rotor resistance and start torque when overloaded, while improving the overload performance of the motor. In practical applications, motors of this structure can withstand an overload of about 1.8 times the rated current and maintain a relatively stable speed.
The role of insulation materials and heat dissipation systems: High-quality insulation materials can withstand higher temperatures, ensuring that the motor will not fail due to insulation damage when overloaded and heated. At the same time, an efficient heat dissipation system can dissipate heat in a timely manner. For example, forced air cooling or liquid cooling can keep the temperature of the motor within a safe range when it is overloaded for a long time, ensuring that its overload capacity is not affected by high temperature.
Overload performance during operation: In actual operation, high efficiency three-phase asynchronous motors have strong overload capacity in a short period of time. Generally, when the load suddenly increases and the current rises to twice the rated current, the motor can maintain operation for a period of time by relying on its own rotational inertia and electromagnetic characteristics to avoid shutdown due to instantaneous overload.
Overload protection and capacity maintenance: In order to ensure that the motor is not damaged when overloaded, an overload protection device is usually equipped. Thermal relays, overcurrent relays, etc. can cut off the circuit in time to protect the motor when the current exceeds the set value. Reasonable setting of protection parameters can not only effectively protect the motor, but also give full play to its overload capacity. For example, setting appropriate delay protection can allow the motor to continue to run when it is overloaded for a short time and complete the necessary work tasks.
Differences in overload capacity under different working conditions: The overload capacity of the motor varies under different working conditions. During the startup phase, the motor needs to overcome a large inertia, and its overload capacity is relatively weak at this time. After stable operation, the motor's overload capacity will be improved. For example, after light-load startup, the motor can withstand a higher multiple of overload current and maintain good operating stability.
Comparison with the overload capacity of ordinary motors: Compared with ordinary three-phase asynchronous motors, the optimization of high efficiency three-phase asynchronous motors in design and manufacturing has significantly improved its overload capacity. Ordinary motors may experience a significant drop in speed or even stall when overloaded by 1.2 times the rated current, while high-efficiency motors can maintain good operating performance at higher overload multiples, providing more reliable power support for industrial production and other fields.
