Parameter identification of second order equivalent circuit of thyristor

The internal damping resistance and damping capacitance of the thyristor have nameplate values when it is just released from the factory, and after using it for a period of time, the parameters of the internal damping resistance and damping capacitance of the thyristor have changed, resulting in deviating from the real value and not being the parameters on the nameplate. To address this problem, this paper designs a parameter identification method for the second-order equivalent circuit of the thyristor based on adaptive control, and the internal damping resistance and damping capacitance of the thyristor. The parameter identification is carried out. In this paper, a Tracking Differentiator (TD) is proposed to extract the input signal with perturbation and filter the input signal to achieve an accurate estimation of the thyristor device parameters. In the identification of parameters, the gradient descent method in adaptive control is chosen in this paper to identify the parameters of the thyristor circuit. Finally, the input signal and the estimated parameters are simulated using MATLAB. The simulation results show that the Active Disturbance Rejection Control (ADRC) strategy applied in this paper can better suppress the disturbances and the adaptive control strategy is faster and more accurate in identifying the parameters inside the thyristor second-order circuit.