Abstract: In order to determine the compensation-type autotransformer starter decompression after the compensation circuitry autotransformer effect and the relationship between the line current, which through the simulation test, simulation start-up process of the load power factor, and the amount of current compensation to be adopted in order to obtain the autotransformer current of the segment. As a result, a more accurate model is obtained. The model reveals the current compensation circuit relationship between each segment so that the complexity of the circuit design is simplified.