Supercritical Carbon Dioxide Power Generation Application with Hybrid PV System for Distribution Networks

Recent studies on using Supercritical Carbon Dioxide (sCO2) as the working fluid showed up to 50% more efficiency compared to the currently used steam power cycle and a size reduction of 10 times, and therefore is of significant interest for power generation applications. In this research the concept of a hybrid system using sCO2 system and renewable energy in a distribution network is studied. An sCO2 electrical generation system was designed to be integrated with renewable energy systems, to help with its vulnerability and increase the stability of the system while connected to the grid. In particular, a sCO2 piston expander, operating under the Brayton cycle, is connected to a PV system. The power from the sCO2 system is converted using an inverter based power system to feed into a node in a distribution network. The electrical system is designed to work with residential photovoltaic (PV) systems, which are volatile to power generation depending on weather conditions and shading factors. A control system is constructed to monitor different aspects of the PV power generation to know if there is a significant drop in voltage, current, or power generation that would have a negative impact on the grid. Simulation of a 13-bus radial distribution network was created, to see the implementation of a PV system with sCO2 system on a residential node and monitor the voltage magnitude. The system demonstrated achieved the ability to keep the voltage magnitude between 0.95 and 1.05pu, as required by the ANSI. The system performance was validated using a small-scale hardware setup that integrated these systems together. The results showed that a microcontroller can monitor and activate the sCO2 system when power generated from the PV system drops due to weather, time of day, and shading/blockage of solar irradiance.