Essence Electrical Power System Modelling & Simulation

The following paper outlines and details both the modelling and simulation of the electrical power system employed on ESSENCE. ESSENCE is a low earth orbiting 3U CubeSat with GOMSPACE P110 PV cells as the primary source of power generation. The PV cells are analyzed under varying ambient conditions and resulting output parameters are identified and recorded. Each step of the modelling process is documented as well as reporting of assumptions made and resulting errors that are identified. A solar irradiance model is also developed to determine solar radiation that is incident upon the PV cell surface. With the radiation model and PV model, simulations are ran to determine power generation capabilities through orbit using pre-built simulations. The final stage to the electrical system that is analyzed includes power management and power storage onboard ESSENCE. A power distribution unit is developed to either charge or discharge the battery as loads are varied and finally, a battery state of charge and charge level model is built. Integrations tests are conducted to determine net power draws, both generation and loads through multiple orbits. The resultant battery state is reported upon conclusion of simulation.