Abstract
This article compares direct turbine throttle control and active turbine throttle control for a turboelectric system; the featured turboprop is rated for 7 kW of shaft output power. The powerplant is intended for applications in unmanned aerial systems and requires a control system to produce different amounts of power for varying mission legs. The most straightforward control scheme explored is direct turbine control, which is characterized by the pilot controlling the throttle of the turbine engine. In contrast, active control is characterized by the turbine reacting to the power demanded by the electric motors or battery recharge cycle. The transient response to electric loads of a small-scale turboelectric system is essential in identifying and characterizing such a system’s safe operational parameters. This paper directly compares the turbogenerator’s transient behavior to varying electric loads and categorizes its dynamic response. A proportional, integral, and derivative (PID) control algorithm was utilized as an active throttle controller through a microcontroller with battery power augmentation for the turboelectric system. This controller manages the turbine’s throttle reactions in response to any electric load when applied or altered. By comparing the system’s response with and without the controller, the authors provide a method to safely minimize the response time of the active throttle controller for use in the real-world environment of unmanned aircraft.
Highlights
A turboelectric system is a turbomachinery-based powerplant that develops its usable energy by burning hydrocarbon fuels, which can be used for applications such as unmanned aircraft
A key challenge for an active controller to overcome is how to handle excess power Tparboldeu3c.eAdTbCyatnhdeDtuTrCbirnesep. oTnhsee etilmecet.rical load can change the power it consumes much more rapidly than the turbine can respond. Because of this difference in response time, a sudden Ipvcthnuooritlwto.tiateaTtgrllheeatidosnincdflfcuaorFnlweliyanb,seaitenolscwTezreeehinlarrlosoiointnpctglecaeurntcPhreeeoinlfesctictutfhtirrreooricenmtnul(otr%fabcudo)ilnlmcetuhinitrsogoRfstfftperltoiseenpm.snotAAitnp(nhTspsege)CerafgatTohterinammneehreeeaiddgt,ohswrttaohhnerbdoreetltpotlhewroeRwevlerohiTDisdnae(piTesmgdnod)Ctnemthhfsoeoeertvloeoorxaltcwdaegasiesss supplied to mit5ig0a–t7e5%the potential voltage spike. 2I.t8i0s important to note th2a.5t the results shown in Figure751–51i0n0c%lude a battery integrated into0.t2h0e system for excess pow1.e1r to flow to, while voltages 5s0ti–ll10re0a%ched above 60 V
A key area of interest for hybrid power systems in aircraft is in vertical takeoff and landing (VTOL) and multi-rotor applications
Summary
The Federal Aviation Administration (FAA) funded research at Oklahoma State University to assemble, test, and integrate turboelectric powerplants to assess proper safe operating parameters and identify potential safety hazards. This class of turboelectric systems generally operates at more than 100 kW of power These UAM concepts utilize electric motors to enable their vertical takeoff and landing (VTOL) flight modes. These UAM concepts utilize electric m2ootfo1r7s to enable their vertical takeoff and landing (VTOL) flight modes. With the application of an electric load to the turboelectric system, the generator rotational speed will lower as the electric motor uses increased torque levels on the turbine shaft, and the electric demand increases This reduction in angular velocity results in a measurable source voltage drop from the turbogenerator combination. The relationship between an electric motor’s KV, voltage, and RPMMot is detailed in Equation (1) [20]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
