Demand response of HVAC systems for hosting capacity improvement in distribution networks: A comprehensive review and case study

With the declaration of the net-zero emission pledge by 2050, improving the hosting capacity of distributed generations is crucial for the distribution system operators to operate the distribution networks efficiently and reliably. This study presents a comprehensive review of hosting capacity improvement methods and demand response strategies using heating, ventilating, and air-conditioning systems. Hosting capacity improvement methods are analyzed through the limiting factors of hosting capacity, including voltage variation, overloading and power loss, and power quality problems, while considering network conditions. Moreover, the optimal demand response strategies that use heating, ventilating, and air-conditioning systems are analyzed while considering network operation, and the practical demand response cases of different countries are summarized. Accordingly, we propose a hosting capacity enhancement method based on the optimal price-based demand response program of heating, ventilating, and air-conditioning systems in commercial buildings considering the overvoltage problem in the distribution network. The proposed method is based on a bi-level decision model that considers the distribution system operator's profits and end-users’ costs and an experimental thermal dynamics model of heating, ventilating, and air-conditioning systems with piecewise linearization. The case studies simulated in a large-scale distribution network reveal that the optimal demand response schedules of heating, ventilating, and air-conditioning systems enhance photovoltaic penetration while maintaining voltage stability and ensuring thermal comfort of the building occupants. The results demonstrate the prospects of developing a demand response program via heating, ventilating, and air-conditioning systems as a hosting capacity improvement method without additional facilities in distribution networks.