A disturbance compensation enhanced control strategy of HVAC systems for improved building indoor environment control when providing power grid frequency regulation

Renewable electricity generations are promising to address the global energy issue while they also place great pressure on the reliability of power grids due to their intermittent nature. In recent years, existing heating, ventilation and air-conditioning (HVAC) systems in buildings have attracted increasing attention to implement continuous demand response in providing frequency regulation service, which can enhance instantaneous power balance and reliability of power grids without extra huge investment. When providing frequency regulation service, the power use of HVAC systems would follow the regulation signals. On the other hand, these signals, acting as continuous disturbances, affect naturally the building indoor environment control at the demand side. In this paper, a novel control strategy is proposed, which can prevent the sacrifice of the building indoor environment when providing the service. The core element of this control strategy is a frequency disturbance compensation scheme, which is developed based on the concept of “disturbance-observer-based control”. Experimental results show that the use of the proposed strategy can achieve significant improvement in the building indoor environment control without sacrificing the quality of frequency regulation service. In addition, the wear level of the valve was not affected significantly when adopting the frequency disturbance compensation scheme.