Impedance analysis of control modes in cascaded converter

Constant power load converter will introduce unstable factor to the cascaded system. Exchanging the position of constant power load converter as the source converter can improve system stability. Active solutions to modify the negative impedance of constant power load converter can also make the system more stable. The concept of coordinative front-to-end impedance control is proposed in this paper, which can assist the cascaded system with better stability. This paper compares converter impedance behaviors between different control methods, and shows that the front-to-end impedance controller can make the system more stable. The conclusions have been validated by simulation results.