Model Predictive Control with Disturbance Observer for Interleaved Parallel Buck Converter

In this paper, a model predictive control with disturbance observer (MPC-DOB) is proposed for interleaved parallel buck converter (IPBC) to achieve both fast transient response and current balance. The duty cycle expression of model predictive control (MPC) is obtained by discretizing the state-space average equation of the converter. Subsequently, a disturbance observer (DOB) is designed to reduce the phase current imbalance caused by model mismatch through estimation and compensation of the parasitic parameters of each phase in the system. The transient performance of the MPC controlled IPBC remain unaffected by reasonable designing the observer parameters of DOB. An experimental platform of 200KHz/45W two-phase interleaved parallel buck converter (2-IPBC) was established to verify that the proposed MPC-DOB control can active fast transient response as the traditional MPC control (the transient adjustment time is about 42 switching cycles). Moreover, MPC-DOB control can achieve current balance.