Characteristic analysis of VFT in asynchronous interconnection of power systems

This paper analyzes the basic structure and working principle of variable frequency transformer (VFT), and sets up the mathematical model of VFT. By the MATLAB, operation characteristic of VFT which is used in AC tie-line to realize the asynchronous interconnection is simulated. The analysis is mainly about the VFT's influence and action on asynchronous power grids interconnection, the stability control of the transmittal power, fault isolation, and such other aspects. The VFT's physical variables, such as the voltage of rotator and stator sides, rotator speed, mechanical torque, transfer power and so on, show that VFT has good asynchronous interconnection capability. The VFT device provides a new way to choose for the interconnection of asynchronous power grids.