Investigation on the use of pumps in HVAC systems for providing ancillary services in smart grids

Abstract

The proportion of electric generation from renewable resource has been growing rapidly in recent years, especially in Microgrids in remote areas. However, the intermitted nature of the renewable energy resource has posed a great pressure on the reliability of power grids and asked a great amount of ancillary services, especially for frequency regulation (FR). Heating, ventilation, and air-conditioning (HVAC) systems are promising resources to solve this challenge because they can take full use of thermal storage capacity of buildings. In this paper, a pump in HVAC system in a hotel is employed to provide the frequency regulation by adjusting its frequency to follow the automatic generation control (AGC) signals, RegA and RegD signals from Pennsylvania-New Jersey-Maryland (PJM). Performance scores are adopted to assess the control performance. In addition, the thermal capacity of the cooling coil is considered to evaluate its side-effect when providing this service. The results indicate that the pump can provide nearly 30kW total capacity with a relatively high average performance score. Moreover, the impact to indoor air temperature is almost neglectable with the thermal capacity of the cooling coil and indoor air hedging against the fluctuation of pump frequency.