Patent ID: 12252264

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made to the drawings wherein like reference numerals identify similar structural features or aspects of the subject disclosure. For purposes of explanation and illustration, and not limitation, a partial view of an embodiment of a system in accordance with the disclosure is shown inFIG.1and is designated generally by reference character100. The systems and methods described herein can be used for controlling hybrid-electric powerplants such as for driving air movers for aircraft thrust.

The system100includes a hybrid-electric powerplant102for an aircraft including a thermal engine104and an electric motor106each operatively connected to provide torque to drive an air mover, e.g. propeller108, for thrust. The air mover is a propeller108, however those skilled in the art will readily appreciate that any other suitable type of air mover such as a fan, ducted fan, or the like can be used without departing from the scope of this disclosure. The electric motor106and thermal engine104are connected together in parallel to a combining gear box (CGB)110. The CGB110connects to the propeller108through a reduction gear box (RGB)112.

A first control loop114is connected for command of the thermal engine104based on error between total torque (MrqTot) commanded, e.g. commanded from a pilot or autonomous system, for the hybrid-electric powerplant102and total response from the hybrid-electric powerplant (MfbTM, torque feedback from the thermal engine104). Commanding the thermal engine104includes controlling fuel flow to the thermal engine.

A second control loop116is connected in parallel with the first control loop114for commanding the thermal engine104based on error between maximum thermal engine output (MrqTMMax) and total torque commanded (MrqTot). A low select118is connected between the first control loop114and the second control loop116to command the thermal engine104with the lower of the responses commanded from the first and second control loops114,116. While torque is used herein as an example of response used for feedback control, those skilled in the art will readily appreciate that any suitable response can be used, such as speed, power, or the like, without departing from the scope of this disclosure.

A third control loop120is connected in parallel with the first and second control loops114,116for commanding speed of the thermal engine104(and/or the propeller108). The third control loop120outputs a speed control enable or disable status of the speed controller122. A high selector124is connected between combined output of the third control loop/speed controller120,122(anded by anding component160) and the low selector118to output MrqTM (torque demanded from the thermal engine104). Sensor feedback128from the RGB is combined with sensor feedback from the electric motor (MfbEM inFIG.1) at box130to determine torque feedback from the thermal engine, Mfb_TM. The prioritization component selects the correct commanded or requested torque MrqTM from among the first, second, and third control loops114,116,120. The requested or commanded torque MrqTM is summed/differenced with the torque feedback from the thermal engine MfbTM at component134, which outputs the error between the two (MrqTM and MfbTM). This sum/difference is passed to the major control loop136, which outputs WfRq (fuel flow required to the thermal engine104) to the minor control loop138, which outputs Wf (actual fuel flow going to the thermal engine104) to the thermal engine104.

A fourth control loop126is connected in parallel with the first, second, and third control loops114,116,120for commanding the electric motor106with non-zero demand when the second control loop116is above control to add response (e.g. torque) from the electric motor106to response (e.g. torque) from the thermal engine104to achieve the response commanded. Commanding the electric motor106includes controlling electrical power supplied to the electric motor106. The fourth control loop126outputs MrqEM, requested torque for the electric motor106. This is summed/differenced with feedback140from the electric motor106at component142, which outputs the error between the two (MrqEM, MfbRM). This sum/difference is passed through the major loop control144, which outputs iEMrq (current commanded by the electronic powertrain controller or EPC) to the minor loop control146, which outputs iEM (actual current going to the EPC) to the electric motor118.

The first control loop114includes a proportional-integral-derivative (PID) integrator148that receives as input the output of a summation/differencing component150. The component150receives total torque demanded or commanded MrqTot and torque feedback of the thermal engine104MfgTM, and outputs the sum/difference to the integrator148. The integrator148outputs to the low selector118.

The second control loop116includes a PID integrator152that receives the output of a summation/differencing component154. The component154receives maximum torque output of the thermal engine104(MrqTMmax) and torque feedback of the thermal engine104(MfgTM), and outputs the sum/difference to the integrator152. The integrator152outputs to the low selector118for selection of the lower of the two outputs of the first and second control loops114,116as described above.

The speed controller122of the third control loop120incudes a PID integrator156that receives the output of a summation/differencing component158. The component158receives propeller speed commanded or required (Nrq) and actual propeller speed feedback (Nfb), and outputs the sum/difference to the integrator156. The integrator156outputs to the anding component160to the integral output is anded with the beta mode input of the third control loop120a described above. The beta mode in this context, and the box labeled “Beta Mode” inFIG.1, refer to speed control mode for the engine control system.

The fourth control loop126includes a PID integrator162that receives the output of a summation/differencing component164. The component164receives the difference between total torque demanded or commanded and maximum torque output of the thermal engine104(MrqTot minus MrqTMmax) and sums/differences this with torque feedback of the electric motor106(MfbEM) to outputs the sum/difference to the integrator162. The integrator162outputs to the142as described above.

The methods herein include constantly resetting a respective integrator148,152,156,162to the value of the loop in control, defined as the loop whose torque request is selected as MrqTM based on the prioritization component132, while the respective control loop is running in the background and is not actively commanding, thus preventing integrator windup error and assuring seamless transition between loops actively controlling the thermal engine104. The respective integrators148,152,156,162are reset with a respective reset command (“Loop in ctrl” inFIG.1) once a respective control loop114,116,120begins actively commanding.

For each control loop114,116,120,126, the PID control integrator path (including the respective integrator148,152,156,162) is reset to the value of the loop in control. For example if the first control loop114is in control (meaning MrqTM=signal from the integrator148of the first control loop114(Loop1inFIG.1), the integrators152,156of the PID controllers for the second and third control loops116,122(Loops2and3inFIG.1) are reset to the value of the signal coming from the PID controller (intergrator148) of the first control loop114(Loop1inFIG.1). This is indicated inFIG.1for each of the integrators148,152,156by the respective arrow designated “Loop in ctl.”

Potential benefits of this disclosure include the following. It is possible to control the power demand of a hybrid-electric powerplant without any abrupt transitions between control loops. The parallel control loops can ensure continuous control of the propulsion system. This architecture can provide an opportunity to adjust the overall system power response of the hybrid-electric powerplant by adjusting the gains and constants of the individual control loops. This can also allow for switching commands from energy/torque demand to a particular engine or propeller speed command.

The methods and systems of the present disclosure, as described above and shown in the drawings, provide for controlling hybrid-electric powerplants such as for driving air movers for aircraft thrust. While the apparatus and methods of the subject disclosure have been shown and described with reference to preferred embodiments, those skilled in the art will readily appreciate that changes and/or modifications may be made thereto without departing from the scope of the subject disclosure.