Fluctuated bus voltage based global temperature control of a DC heat pump for integration with building-integrated photovoltaic system

Building-integrated photovoltaic often suffer from fluctuated bus voltage, which may influence the operation of building equipment and indoor thermal environment in buildings. Heat pump systems have potential of providing flexible and substantial power adjustment for integration with building-integrated photovoltaic systems. In order to maintain steady operation of direct-current heat pump systems without sacrificing indoor thermal comfort, this paper proposed a fluctuated bus voltage based global temperature control strategy of a direct-current heat pump for building-integrated photovoltaic system. Data collection on real photovoltaic buildings was performed to obtain the energy source and load characteristics in buildings integrated with photovoltaic system. Following this analysis, the global temperature control strategy is proposed, which sets indoor temperature based on different bus voltage conditions. This approach aims to adapt to photovoltaic power fluctuations while ensuring that indoor comfort requirements are met. Results indicated that during high-solar-radiation periods, the proposed strategy could enhance photovoltaic power consumption by an additional 9.29% and 14.32%. It also effectively maintains the heat pump's operation within acceptable limits for voltage fluctuations, ensuring essential thermal comfort in the building. The electricity demand of the building can be reduced by 21.88% during the heating season and 13.26% during the cooling season.