To solve the problem of starting the power frequency cage motor, soft starter or reduced voltage starter can be used, but there are many additional equipment and complicated control links, which is not as simple and flexible as the inverter power supply method. However, a series of practical problems derived from this must be taken seriously.

First, the power supply of industrial frequency motor inverter may be aimed at the starting problem. Then it brings great benefits in speed regulation. The problem is not that simple. At first, it does not stop at solving the starting problem, but gradually improves the equipment.

Second, the industrial frequency motor powered by the inverter is very suitable for many applications. The economic benefits and low starting point of application technology have further promoted its large-scale promotion. There may be a qualitative change in the ventilation and heat dissipation conditions of the motor: when used in low-frequency state, the wind pressure generated by the motor's own fan is too low, and the winding is seriously heated;

Third, the reliability of the motor insulation system is not enough to withstand the impact of the high-frequency pulse wave of the inverter, and the initial turns of the winding power supply are very prone to electrical faults such as inter-turn, inter-phase or to ground.

In order to cope with the normalization of frequency conversion use of industrial frequency motors, many motor manufacturers have specially designed a wide-frequency motor, strengthened the motor winding end binding and ventilation and heat dissipation links, and adopted measures such as vacuum pressure impregnation process to greatly improve the reliability of the motor insulation system.

Why do some customers use industrial frequency motors as variable frequency motors instead of special variable frequency motors? In addition to the above factors, the most important direct reason is that the price of variable frequency motors specially used in inverter power supply occasions is much higher than that of standard industrial frequency motors. Because the heat exchange effect of the ventilation and heat dissipation system of the variable frequency motor is no longer dependent on the motor speed, it is equipped with an independent fan, and the winding coil uses special electromagnetic wire for variable frequency motors, which leads to a significant increase in manufacturing costs.

Although the cost of using variable frequency starting for industrial frequency motors is higher than the original starting method, the series of benefits it brings far exceeds customer expectations. The evolution to variable frequency starting has become an additional value, and the upgrade and improvement of the equipment system is the goal to be pursued .