Overview of Buck and Boost converters modelling and control for stand alone DC microgrid operation

Abstract

This paper presents an overview on Buck and Boost converters, and their control system for DC Microgrid operation in stand alone mode. The Buck and Boost converters can be considered as the basis of a number of other converters, therefore the control system presented can be extended to other similar applications. The Buck and Boost converters can be used to interface photovoltaic (PV) panels or wind turbine systems to the DC microgrid. The Buck and Boost converters will be modelled in continuous conduction mode (CCM), and the control system needed to integrate these converters to the DC microgrid will be presented. Nested control loops are used to control the current and voltage of the Buck or Boost converter. Another loop applying droop control is used to obtain load sharing when converters are paralleled in a microgrid. Then, a voltage restoration loop is applied to restore the desired voltage in the dc microgrid, correcting any voltage deviations caused by the droop loop. The operation of the control loops will be tested by simulating two paralleled Buck converters operated in CCM while sharing a common resistive load.