This SBIR Phase I develops hardware and software for energy management in electric VTOL aircraft. It focuses on techniques to ensure short-time-scale stability in power micro-grids, and optimization-based control at somewhat longer (~10-100 ms) time-scales for propulsion system and vehicle control, which is managed by a vehicle Energy Management System (vEMS). Fast optimization and model-based decision making are key to the approach. Experiments will be conducted with a hybrid power plant consisting of an internal combustion engine, an iron-less dual-halbach-array starter motor/generator, and a new 6-phase regenerative motor drive. The project is organized into three Technical Objectives: TO #1: Reconfigurable Component, Subsystem, and System Topology Models Reconfigurability is enabled at three levels in the vEMS-controlled system. At the component level, parametric models are used so that components in a new vehicle system or a faulted system can be configured with a parameter list. Subsystems are similarly configured. At the system level, the topology is reconfigurable because of technical conditions (incremental passivity) placed on each component to ensure that the assembled micro-grid is stable regardless of the interconnection. With stable short-time-scale dynamics, the vEMS uses component models to optimally manage interactions on the micro-grid. TO #2: Incremental Passivity with Application to a 1.5kW Regenerative Drive LaunchPoint proposes to design a 1.5kW regenerative drive for the 6-phase starter motor/generator such that it is incrementally passive as seen from the bus. TO #3: Real-Time Optimal Control for Energy Management The project will make use of a recently developed tool, named TensCalc, that generates specialized C-code for real-time decision and control with up to a few thousand optimization variables/constraints. This fast optimization tool will be at the heart of the vEMS system and enable millisecond time-scale decision making. Potential NASA Applications This project relates to NASAs efforts in electric and hybrid-electric flight, urban air mobility (UAM) and research in power electronics. NASA vehicles and concepts related to this work are the X-57, GL-10, and SUGAR Volt. Potential Non-NASA Applications The US Department of Defense and number of companies are developing or have interest in electric and hybrid-electric flight. Commercial entities include Uber, Amazon, Vayu, Elroy Air, Martin Aerospace, Boeing, and numerous others.