Novel Passive Controller Design for Enhancing Boost Converter Stability in DC Microgrid Applications

Boost converters have nonminimum phase (NMP) characteristics, which makes the stable closed-loop control design difficult. Based on the passive theory, this article proposes to add a feedforward loop in the conventional double-loop closed loop to compensate for the NMP effect. Therefore, the potential instability caused by NMP can be avoided. Such compensation is especially useful for dc microgrid applications where boost converters are widely used as interface converters. Two types of feedforward gain are discussed and compared. The gain of K with a high-pass filter is used eventually for integrating with conventional droop control because it does not change the low-frequency quiescent operation point. The stability of the proposed controller is analyzed through loop gain on the s plane. Besides, how the output impedance of the converter is shaped by the passive controller is analyzed. The experimental results validate the effectiveness of the proposed passive controller.

Automated summary

This article proposes adding a feedforward loop in the boost converter closed-loop system to compensate for nonminimum phase (NMP) effect and avoid potential instability. The stability of the proposed controller is analyzed through loop gain on the s plane, while the shaping of output impedance is also discussed. These passive control methods are validated to be effective in experimental results.