Hybrid power system

Hello, I am currently working on making a hybrid power system using IC engine and generator/ alternator/ motor for a UAV (VTOL capability - quadcopter and fixed wing combo) we are designing for MEng project. I have found some information on alternator by Sullivan and other company/forums. I have also looked into using motors to generate elec but not sure as how I would be able to generate sufficient power. Current chosen motor spec - 42amp draw continuous and rated at 850watts each. takes 4-5s lipo. Any suggestions??     

You need to be a member of diydrones to add comments!

Join diydrones

Email me when people reply –

Replies

  • I need an alternator for 8500 KW power and less than 5 KG weight 
    would you please introduce me some, if you know any models or companies
    thanks 

    soundcloud downloader

    Soundcloud Downloader
    Soundcloud Downloader high quality mp3 tracks : ✓ No registration required ✓ Extremely fast ✓ Totally free ✓ Easy to use
  • hello I'm interested in the subject
    I was thinking of using a gasoline engine for aircraft that develops between 4 and 5 hp
    what do you think?

  • A couple of things to consider:


    A permanent magnet motor used as an alternator doesn't have a "field" winding to regulate the voltage. As a result, the output voltage will be almost directly proportional to the RPM, so if you want a constant voltage to the motors you will have to keep the engine at a fixed RPM. If the engine doesn't hold a nearly constant RPM with varying load, you will need a governor.  You COULD use a buck regulator to keep the voltage constant, but good luck in finding a suitable one!

    Even the best 100PIV/60A Schottky bridge rectifiers have a voltage drop of about 1.7V, so if you are producing 40A, you will create 68 Watts of heat in the rectifier.  The only way to avoid this is to use active (FET) rectification.

  • Hi, i want build a hybrid drone but have a problem for the motor brushless.
    It i have a 200kv at 8000rpm i have 40volt, but not know the amp
    Can you help me?
  • Lekhraj,

    I'm new to DIY Drones but I've logged quite a few hours looking into this concept for my own quadcopter power endeavorers. The math I had checked out, but barely. Don't expect a heavy lifter. The fixed wing may buy you some flight time though. Some motors and generators have incredible peak efficiencies but thats the peak and not the average. I hunted all over and came to the conclusion that you should expect 50% of the power created by the engine to be available at the props in no  battery equilibrium. To enplane in over simplified terms 70% efficiency at the generator times 70% efficiency at the motor is 49% total. In reality these numbers could be a little higher or lower and you also have losses in the ESC (but I don't think that much). Eventually I went with single engine direct drive which was a mechanical nightmare but o-so-much power (90%+ efficiency).

    To start off your power design pick an engine that has about twice the power you think you will need (convert horse power to Watts). Keep in mind that rated horse power is what the engine manufacture decides to stamp on the engine and should not be considered to be exact. Now to ask gasoline or nitro engine? List goods and bads of the systems in general and for specific engines you think will suit your purpose.

    For your generator I would suggest a brushless motor just like all the other hobby grade components you will be using. There is a clever way to use 6 diodes rectify the power coming from the three leads with minimal electric penalty (http://www.instructables.com/answers/Windmill-Generator-why-wont-a-...). The instructables discussion is kinda long and has some useful stuff in it but you really just need the picture partway down with 6 diodes drawn on it. As far as which motor to get? get something with as low of a kV(motor constant) rating as possible. It is easy to step voltage down and will even let you get away with an undersized generator as higher voltage means less required amps which means less damaging heat.

    Brushless motors come in much greater variety then engines so you may need to try 2 or three generators before finding something can convert your power efficiently and is light weight. If you have the luxury of sizing the rest of your airframe after this life would be easier.

    Another better thought, if you relayed on half to 3/4 battery power to VTO&L and fixed your foreword flight prop directly to the engine and in-line with the generator you could get by with much less of a generator if you even still feel the need to have a generator. Best of both worlds.

  • I could be interested in this, do you guys have a budget for this project? 

    If we built a lightweight APU maybe from one of my small nitro engines, using a lipo pack and brushless that both starts the engine and is used as a alternator.

    If the nitro engine is tuned right it could be relitivlty efficient, however I have been playing around with a nitro engine running on a Hydrogen Gas mix... I think if we can make a lightweight fuelcell we would be in business

  • HERE is a previous discussion about the idea..

    -=Doug

    • Thankyou for your reply. Greatly helped

This reply was deleted.

Activity

DIY Robocars via Twitter
RT @TinkerGen_: "The Tinkergen MARK ($199) is my new favorite starter robocar. It’s got everything — computer vision, deep learning, sensor…
Monday
DIY Robocars via Twitter
Monday
DIY Robocars via Twitter
RT @roboton_io: Join our FREE Sumo Competition 🤖🏆 👉 https://roboton.io/ranking/vsc2020 #sumo #robot #edtech #competition #games4ed https://t.co/WOx…
Nov 16
DIY Drones via Twitter
First impressions of Tinkergen MARK robocar https://ift.tt/36IeZHc
Nov 16
DIY Robocars via Twitter
Our review of the @TinkerGen_ MARK robocar, which is the best on the market right now https://diyrobocars.com/2020/11/15/first-impressions-of-tinkergen-mark-robocar/ https://t.co/ENIlU5SfZ2
Nov 15
DIY Robocars via Twitter
RT @Ingmar_Stapel: I have now explained the OpenBot project in great detail on my blog with 12 articles step by step. I hope you enjoy read…
Nov 15
DIY Robocars via Twitter
RT @DAVGtech: This is a must attend. Click the link, follow link to read the story, sign up. #chaos2020 #digitalconnection #digitalworld ht…
Nov 15
DIY Robocars via Twitter
RT @a1k0n: Got a new chassis for outdoor races (hobbyking Quantum Vandal) but I totally didn't expect that it might cause problems for my g…
Nov 11
DIY Drones via Twitter
First impressions of the Intel OpenBot https://ift.tt/36qkVV4
Nov 10
DIY Robocars via Twitter
Nov 9
DIY Robocars via Twitter
Excellent use of cardboard instead of 3D printing! https://twitter.com/Ingmar_Stapel/status/1324960595318333441
Nov 7
DIY Robocars via Twitter
RT @chr1sa: We've got a record 50 teams competing in this month's @DIYRobocars @donkey_car virtual AI car race. Starting today at 10:00am…
Nov 7
DIY Robocars via Twitter
Nov 6
DIY Robocars via Twitter
RT @a1k0n: Car's view, using a fisheye camera. The ceiling light tracking algorithm gave me some ideas to improve ConeSLAM, and having grou…
Nov 5
DIY Robocars via Twitter
RT @a1k0n: To get ground truth I measured the rug, found the pixel coordinates of its corners, calibrated my phone camera with my standard…
Nov 5
DIY Robocars via Twitter
RT @a1k0n: @DIYRobocars is back in December, but outside. Time to reinvestigate ConeSLAM! I rigged up a quick and dirty ground-truth captur…
Nov 5
More…