Sliding-mode Control of Single-phase PWM Rectifier for DC Micro- grid Applications

DC micro-grid is a novel ideal of advanced electricity delivery infrastructure which actively integrates a variety of renewable sources, energy storages, and loads within a local network; this type of lumped system organization can offer a fast, high quality and survivable solution for future residential and industrial power network. DC micro-grids can be the building block of future smart-grid, which performs proper power management for the sources, storages and customers within, and interact with the smart-grid in an optimal manner. AC-DC converter as the only grid-end interface to the utility grid can achieve bidirectional power processing with high power factor and low harmonics, which ensures sustainable and economical operation of the DC micro-grid. In this paper, the rectification mode of the AC-DC interface (PWM rectifier) is studied; sliding mode control is used in PWM rectifier controller design; different sliding surface coordinate functions are evaluated for sliding-mode control in detail based on a derived large signal converter model; finally the sliding-mode controller in conjunction with a traditional PI controller are designed for current loop and voltage loop respectively. The proposed control system is implemented in a TMS320F2812 digital signal controller and tested with a five-port interface to DC micro-grid, satisfactory results are collected.