1、When the rotating motor operates in an asymmetric state, it will cause additional loss and heat to the rotor, which will cause the whole or local temperature rise of the motor. In addition, the additional torque generated by the reverse magnetic field will cause the motor to vibrate. For the generator, a series of higher harmonics will be formed in the stator.  

2、Many kinds of protection with negative sequence component as starting element are misoperated, which directly threatens the operation of power grid. 

3、Unbalanced voltage causes non characteristic harmonics in silicon rectifier。  

4、For generators and transformers, when the three-phase load is unbalanced, if the maximum phase current is controlled as the rated value, the other two phases cannot be fully loaded, so the utilization rate of the equipment decreases. Otherwise, if the rated capacity is to be maintained, the overload of one phase with large load will be caused, and the unbalanced magnetic circuit will cause waveform distortion, and the additional loss of the equipment will be increased。

1、In order to reduce the problem of unbalanced degree caused by the centralized connection, the asymmetrical load is connected to different power supply points。  

2、Use the method of cross exchange to distribute the unsymmetrical load to each phase reasonably and balance it as much as possible。 

3、Increase the short-circuit capacity of the load access point, such as changing the network or improving the power supply voltage level to improve the system's ability to withstand unbalanced load。