High-Precision Modeling and Online Validation of a 200kW-Class Series Hybrid Power System in Aviation 2023-01-7097

Taking into account the high rotor speed of the generator and the trend of high voltage in direct current microgrids in high-power aviation hybrid propulsion systems, a hybrid power system with a power of 200 kilowatts (kW), a voltage of 540 volts (V), and a rated generator speed of 10500 r/min was established. Anticipating the demands of future high-power system tests, a matching simulation model was developed. The paper discusses various aspects including model construction, test design, and result validation, proposing an overall control strategy for series hybrid aviation propulsion systems – utilizing lithium-ion batteries to stabilize grid voltage and using the turboshaft-generator unit as the primary power source to meet the main power demands of the electric propulsion system. The established model consists of four modules: turboshaft engine, power generator, voltage-stabilizing battery, and electric motor/propeller. These modules are independently controlled and are unified into a microgrid through a direct current bus. In the designed cases, the simulation data including generator speed, gas turbine speed, grid voltage, and component power were compared and analyzed against experimental data. The results indicate that both steady-state and dynamic errors of the simulation are controlled within 10%. This implies that the constructed simulation model accurately replicates the operational state of the 200 kW-level series hybrid aviation propulsion system. It serves as a pre-research platform for testing system control strategies and developing new control algorithms. Finally, the feasibility of a strategy to appropriately increase the power of the turboshaft-generator set and maintain battery output power fluctuations within 0 kW was validated within the simulation system, providing a reference for future experiments.