Modelling of a Hybrid-Electric System and Design of Load-Following Control Law on Hybrid-Electric Urban Air Mobility Power Plants

摘要

This paper describes the developed control strategies for the hybrid-electric engine system for Urban Air Mobility (UAM) applications by the Eagle Flight Research Center (EFRC) at Embry-Riddle Aeronautical University (ERAU). It will also provide details of the hybrid-electric engine simulation developed in MATLAB with Simulink and Simscape to test the control logic. Simulation models of the internal combustion engine, generator, inverter-motor controller, battery pack, load generator (UAM vehicle) along with a supervisory controller are detailed in the paper. These control strategies were then implemented on a 100kW hybrid power plant to test and validate the effectiveness of the control system. The power plant consists of a 4-cylinder turbocharged Rotax 915iS gasoline engine powering YASA P400RHC. The system also consists of a Cascadia PM 150 DZ to control the generator along with Lithium-ion battery packs connected in parallel. This paper explains the supervisory controller that manages all the components within the hybrid-electric power plant to achieve the required power. The principal concepts in controlling the system are meeting the powertrain load requirement from the generator, regulating the battery current to zero, and maintaining the state of charge (SOC) of the battery pack.