Model predictive control for the reference regulation of current mode controlled DC-DC converters

Abstract

The control of DC-DC converters for high performance applications usually relies on Current Mode Control (CMC). Compared to voltage mode control, it guarantees automatic over-current protection, and a better closed loop stability, together with improved transient response. This paper presents a Model Predictive Control (MPC) algorithm for the regulation of the voltage reference signal in CMC. The control of pre-compensated systems via MPC is common in several fields, such as automotive and aerospace, and power electronics is a perfect candidate to exploit this hierarchical structure as well. Indeed, controllers for power converters are often coded in the integrated circuits, and cannot be changed. Furthermore the possible multirate structure allows to exploit the performance of MPC less affecting the computational cost. The paper describes the design of an MPC regulator for a synchronous buck converter, when a primal CMC is already coded. Performance improvements of the proposed controller are reported.