Autonomous distributed secondary loads for sole frequency regulation in high penetration wind-diesel microgrids

Abstract

Remote islanded microgrids are frequently powered by combinations of diesel electric and wind power generation. In such grids excess wind power can be curtailed, dumped or used to provide space heat or domestic hot water. Use of electric thermal storage (ETS) devices provides a means for conversion of electrical energy to distributed heat and subsequently frequency regulation as autonomous distributed secondary loads (ASDL). The present study offers a means of using ETS units to inherit sole frequency regulation responsibility from the diesel generator while keeping the diesel engine at its minimal optimal loading. Numerical modelling of system dynamics with active ADSLs is conducted using a SIMULINK® wind-diesel hybrid test bed model with the capability to disengage the diesel engine during periods when wind power output is greater than system demand. It is shown that the ADSLs can maintain frequency regulation in high penetration wind-diesel and wind-only modes.