Decoupled building-to-transmission-network for frequency support in PV systems dominated grid

Abstract

Tendency towards installation of distributed photo-voltaic (PV) systems has led to an increased emphasis on grid frequency control. Grid-interactive buildings equipped with heating ventilation and air conditioning (HVAC) system has a great potential to regulate the frequency in renewable energy resources rich grids. This paper integrates distributed PV systems in a decoupled building-to-transmission-network (B2TN) and explicitly formulates the interaction between a grid and the buildings through real time pricing (RTP). As grid frequency conveys the information about operating conditions of a power system, therefore, frequency based RTP generators namely; linear, hyperbolic tangent and inverse hyperbolic tangent are used. A price responsive model predictive controller (MPC) for optimal scheduling of HVAC load is developed where reference temperature set point is dynamically adjusted subject to RTP. Moreover, the clear and cloud covered sky impacts of PV power generation on frequency and RTP deviations are investigated. Comparatively, inverse hyperbolic tangent model maps the frequency deviations on a wider RTP range which increases the scale of reference temperature set point resulting peak frequency deviation suppression up to 40% and load regulation beyond 12 MW without inherently affecting the building electricity cost when compared to ordinary MPC (without demand response service).