With the development of power electronic technology, the use of variable frequency technology has become more and more widely. Therefore, more scholars have been concerned about the modeling and analysis of variable frequency. In addition, due to the access of distributed power, frequency has a great impact on the power grid, so, it is important to consider the frequency characteristics of the load. In this paper, two methods are used to model the frequency conversion motor model. One is the variable frequency speed regulation vector control method, the other is dynamic phasor method. And finally, compared with the motor that not consider the frequency characteristics to find the load model which fit for the truth.