Robust control of DC-DC converter by approximate two-degree-of-freedom digital controller with second-order differential disturbance characteristics

Abstract

Robust DC-DC converter that can function with a single controller over a wide range of load and input voltages is required. In such a case, changes in the output voltage must be suppressed. We propose an aproximate two-degree-offreedom (2DOF) digital controller that realizes the start-up response and dynamic load response independently. The controller makes the control bandwidth wider and suppresses the variations that occur in the output voltage due to sudden changes in loads and input voltages. In this paper, a new approximate 2DOF digital controller that involves the additinal zeros is proposed. The controller greatly suppresses the variations that occur in the output voltage due to sudden changes in loads and input voltages, This controller is actually implemented on a digital-signal-controller (DSP) and is connected to a DC-DC converter. Experimental studies demonstrate that this digital controller can satisfy the given specifications. © 2009 The Institute of Electrical Engineers of Japan.