College of Electrical and Electronic Engineering, Shandong University of Technology, Zibo 255000, China

Under the condition of high power disturbance, the limiter is prone to the saturation phenomenon of duty cycle, and the DC power distribution system will be degraded from closed-loop control to open-loop response and transient instability. Therefore, this paper carries out the transient stability analysis of DC power distribution system considering the duty cycle limiter. Firstly, this paper uses Sigmoid function to simulate the nonlinear characteristics of duty cycle limiter, and establishes a large-signal model of DC distribution system which is closer to the engineering reality. Secondly, the estimated attraction domain taking into account the influence of the duty cycle limiter is characterized by the Takagi-Sugeno (TS) fuzzy modeling method. Then, the variation of the estimated attraction domain with different control parameters reveals the transient instability phenomenon of the DC distribution system induced by duty cycle saturation. Finally, for the limitations of the existing transient stability improvement methods due to the duty cycle limiter, an optimization design method of control parameters is proposed to provide a scheme for the control parameter selection to improve the transient stability of the system. The effectiveness of the theoretical analysis is verified by the RT-Box hardware-in-the-loop experiment.

This work is supported by Shandong Provincial Natural Science Foundation of China (No. ZR2023ME034).