https://orcid.org/0000-0003-1742-5526Thursday 30 December 2021
How to Build Simple Model of PEM Fuel Cells Using Matlab Simulink
How to Build Simple Model of PEM Fuel Cells Using Matlab Simulink
Friday 17 December 2021
Sunday 12 December 2021
Design of NASA Robotic MARS Helicopter Using Matlab Simulink
This example shows how to use Simscape™ Electrical™ to model a helicopter with coaxial rotors suitable to fly on Mars.
This helicopter takes inspiration from Ingenuity, the robotic helicopter developed by NASA, which accomplished the first powered flight on another planet.
References:
https://in.mathworks.com/help/physmod/sps/ug/mars-helicopter-system.html?s_eid=psm_ml&source=15308
Withrow, S., Johnson, W., Young, L. A., Cummings, H., Balaram, J., & Tzanetos, T. (2020). “An Advanced Mars Helicopter Design”. ASCEND 2020. doi:10.2514/6.2020-4028
Pipenberg, B. T., Keennon, M., Tyler, J., Hibbs, B., Langberg, S., Balaram, J. (Bob), Pempejian, J. (2019). “Design and Fabrication of the Mars Helicopter Rotor, Airframe, and Landing Gear Systems”. AIAA Scitech 2019 Forum. doi:10.2514/6.2019-0620
Balaram, B., Canham, T., Duncan, C., Grip, H. F., Johnson, W., Maki, J., Zhu, D. (2018). “Mars Helicopter Technology Demonstrator”. 2018 AIAA Atmospheric Flight Mechanics Conference. doi:10.2514/6.2018-0023
Contents
Introduction – MARS Helicopter Technology
Introduction - Mars Helicopter System-Level Design
Simulink Model – NASA Robotic MARS Helicopter
Model Overview & Battery Pack Variant
Flight Control System & Command Dashboard subsystem
Simulation & Result Analysis:
Altitude and Battery Cell Temperatures
Flight Duration Vs Number of Battery Cells
Introduction – MARS Helicopter Technology
The Mars Helicopter is an autonomous 1.8 kg co-axial, counter-rotating rotorcraft baselined to fly on the Mars 2020 mission to demonstrate aerial mobility on the surface of Mars.
The rotor system consisting of the rotor blades, hub mechanism, propulsion motors, swashplates and linkages, control servos, and primary helicopter structure.
The landing gear system consisting of 4 deployable legs, landing feet, and suspension mechanisms.
Auxiliary structures, including the structural elements of the Helicopter Warm Electronics Box (HWEB) that encloses the electronic core module (ECM) and battery, and the solar array substrate that serves as the structural element of the solar panel system.
The solar array located above the blades is used to recharge the helicopter batteries during the day to provide power for flight operations and overnight thermal survival.
This example shows how to use Simscape™ Electrical™ to model a helicopter with coaxial rotors suitable to fly on Mars.
This helicopter takes inspiration from Ingenuity, the robotic helicopter developed by NASA, which accomplished the first powered flight on another planet.
To control the helicopter altitude interactively, can use the blocks in the Command Dashboard subsystem.
The helicopter model comprises
Solar Panel,
Battery Pack,
Heater,
Motor & Drive,
Two gearboxes
Two contra-rotating coaxial rotors,
1D mechanical model of the gravity, drag, mass, and ground contact forces.
Click here to download the model:
2021a version:
https://drive.google.com/file/d/1M8IaiPS18JpqkPC8Qe4U7P4x1x_j4Q4c/view?usp=sharing
021b version
https://drive.google.com/file/d/1Lox1X363nFNrMaLXKTghBR7X4LhpONfu/view?usp=sharing
Tuesday 7 December 2021
Modeling & FFT analysis on PCC- Inverter-based Micro grid with Droop Control Technique Using Matlab
This example shows the islanded operation of an inverter-based microgrid using droop control technique.
With the droop control technique, PLL are not required to achieve system-wide synchronization because all inverters reach the same frequency.
The microgrid consists of three parallel inverters subsystems, with power ratings of 500 kW, 300 kW and 200 kW respectively, connected to the PCC (Point-of-Common-Coupling) bus.A dynamic load model is used to dynamically change the microgrid total load.
The Microgrid Supervisory Control system, when enabled, modifies the inverters P/F and Q/V droop set points in order to bring back the microgrid frequency and voltage at their nominal values (60 Hz and 600 Volts respectively).
The example illustrate the operation of an inverter-based microgrid disconnected from the main grid (islanded mode), using the droop control technique.
Each inverter subsystem contains a three-phase two-level power converter, an LC filter, a 480/600V transformer as well as an ideal DC source to represent the DC link of a typical renewable energy generation system (such as PV array, wind turbine, battery energy storage system).
Each subsystem also includes a control system and a PWM generator feeding the inverter.
The analysis is based on the frequency reference that capable in generating the output of voltage and current as well as the equality of load power sharing when a load disturbance occurs in the parallel-connected inverters.
The FFT Analyzer app allows we to perform Fourier analysis of simulation data and provides access to all the simulation data that are defined as structure-with-time variables in our workspace.
The app displays the spectrum as a bar graph or as a list in percentages relative to a base value or to the DC component of the signal.
To Open the FFT Analyzer App:
MATLAB command prompt:
Enter powerFFT
Analysis :
At 1 s, the total micro grid load is increased from 450kW/100kvar to 850kW/200kvar. At 3 s, droop control is enabled on all inverters.
We can see that the micro grid load is now shared equally among the three inverters.
At 5 s, the supervisory control is enabled. The frequency is then being slowly increased to 60Hz and the line voltage to 600V.
The droop P/F is set to 1%, meaning that microgrid frequency is allowed to vary from 60.3 Hz (inverter produces no active power) to 59.7 Hz (inverter produces its nominal active power).
The droop Q/V is set to 4%, meaning that the microgrid voltage at the PCC bus is allowed to vary from 612 Vrms (inverter produces its full inductive power) to 588 Vrms (inverter produces its full capacitive power). Note that Qmax is specified as half of the nominal active power Pnom.
To demonstrate the impact of the inverters PWM carrier’s initial phase on the PCC bus voltage harmonic content, first open the FFT Analyzer App to perform an FFT analysis of the PCC phase A bus voltage.
In the App, set the Structure with time parameter to PCC , the Signal parameter to V_PCC, and the Dimension parameter to 1 to analyze the PCC phase A bus voltage. Set the Zoom on parameter to FFT window , the Start time parameter to 7.9 , and the Max frequency parameter to 7000. Click Compute FFT. In the FFT plot, the maximum harmonic occurs around the switching frequency (2700 Hz) and is close to 2%.
Now, double-click on the Inverter 2 (300 kW) subsystem and change the Carrier initial phase parameter to -90 degrees. Rerun the simulation and again, perform an FFT analysis on the PCC phase A voltage. We should see that this new carrier phase setting significantly reduces the harmonic content around the switching frequency (2700 Hz). This is due to the fact that Inverter 1 carrier phase is set to +90, so switching harmonics are then partially canceled.
Click here to download the file:
2020a version:
https://drive.google.com/file/d/15A6V1SPbP9hXL9zLO7j4bvgvJiYNwepl/view?usp=sharing
2021a version:
https://drive.google.com/file/d/1t6WCRfMjqF6ku2x04iCJ0nJmgFv5dQPZ/view?usp=sharing
2021b version:
https://drive.google.com/file/d/10sDfAa9AWhWMGn00mkRRgnnyEARy30hQ/view?usp=sharing
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