FAULT RIDE-THROUGH CIRCUIT WITH VARIABLE FREQUENCY TRANSFORMER AND CONTROL METHOD THEREOF

A fault ride-through circuit with a variable frequency transformer (VFT) and a control method thereof are provided, and the control method comprises: pretreating acquired voltages of grids, a voltage of a stator interface and a voltage of a rotor interface to obtain a rotor voltage DC component and a rotor voltage DC component; testing and treating a voltage frequency of a first grid and a voltage frequency of a second grid; carrying out a reference voltage calculation for a stator voltage DC component, a rotor voltage DC component, the voltage frequencies of the first grid and the second grid to obtain a positive voltage reference value of the first PWM convertor and the second PWM convertor, and processing the voltage reference values to obtain the switch signals for controlling the first PWM convertor and the second PWM convertor.