Equivalent input disturbance observer-based ripple-free deadbeat control for voltage regulation of a DC–DC buck converter

In this research, voltage regulation of a DC-DC buck converter is realised via the ripple-free deadbeat control (RFDBC) with the equivalent input disturbance observer (EIDO). A small-signal state-space model is constructed for the RFDBC design of a converter. Faced with mismatched models, unknown parameter perturbation, and time-varying voltage source and load demands, augmented disturbance state is constructed and extended state observer is utilised to estimate this augmented model accurately. Based on this model, EIDO is proposed to evaluate the equivalent input disturbance affecting on the input channel. Disturbance compensation is analysed in theory, and the simulation model of the proposed EIDO-based RFDBC is created to illustrate the control performance in MATLAB/Simulink. Finally, a LabVIEW-based FPGA experimental rig is set up for the voltage regulation of a DC-DC buck converter. Two other controllers, RFDBC without EIDO and active disturbance rejection control are also designed for performance comparison. The performance comparison result of transient tracking indicates the outstanding characteristics of the proposed controller.