Exploring Non-Convexity Characteristics of Active Trap Filter Based on Local Optimal Control

The active trap filter (ATF) plays a pivotal role in manipulating high frequency switching harmonics with superior flexibility. However, theoretical calculation value of controller's parameter is not accurate and weather the parameter is optimal has not been confirmed. To address this issue, this article starts with single targeted switching frequency, proposing a local optimal control parameter tuning algorithm to locate the local optimal value of each controller. What is more, after each local optimal parameter is found, when all controllers working together, controllers' interactions and the non-convexity characteristic of the active trap filter are observed based on the global system. The effectiveness of the algorithm and the system non-convexity characteristic are verified by simulations.