Proposal for faster disturbance rejection of boost DC-DC converter based on simplified current minor loop

Abstract

Boost converters contain a right half plane (RHP) zero. This RHP has severe limitations on the bandwidth of controllers. Further, this RHP makes it difficult to design fast disturbance rejection approaches, such as disturbance observers (DOB). This paper tackles the problem of designing a DOB based control law of the boost converter. This is done by designing a dual loop feedback controller. The designed controller is called current-minor-loop (CML) control. With CML, it is possible to make a fast response of inductor current to track reference current. Following that, the CML can be reformulated such that the current loop is considered unity. Further, the CML is simplified to make the boost converter minimum phase (MP) system. The formulated control approach is validated by simulations using PSIM software. Then, this method is verified by experiments on a boost converter loaded with resistive load.