ฝัง
- เผยแพร่เมื่อ 19 ต.ค. 2017
- Inverters have taken a prominent role in the modern technological world due to the sudden rise of electric cars and renewable energy technologies. Inverters convert DC power to AC power. They are also used in Uninterruptible Power Supplies, Control of Electrical Machines and Active Power filtering. This video will explain how to get a pure sinusoidal electric power output from DC power input in a step by step logical manner.
I thank Mr. Nachiketa Deshmukh for his extensive technical support in creation of this video. He is a Phd scholar at IIT Kanpur. Check out his Google scholar profile.
scholar.google.co.in/citation...
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I'm Eletrical Engineer, I would like so much has in that time a high quality material to learn simple like that. Congrats for your work and many thanks to keep posting intelligent and crucial videos for all professionals!
I study Electrical Engineer and we still don't have this high quality explanations. Also because our teacher also does not know how this works lol.
It was in '93 people barely knew what a transistor was yet... How you expect to havE this kind of explanation in 93... Lol wat
every single comment here gives me a headache.
Same
Electrical engineer/Power Distribution engineer 😎
Only two days ago I was looking for a decent video explanation of an inverter and found nothing. Can't believe you released this, it is exactly what I was looking for! Perfect explanation!
This was quite good. I've studied electronics several times in my life and still struggle with understanding. I'll follow you now
After years of "Audio Engineering" (Very loose emphasis on the engineering part, Lol) this has demystified a massive chunk of it all for me. This is awesome material. Currently building a Neve 1073 microphone preamp clone, and this is going to help me quite a bit to wrap my gourd around what each component is doing. Mind blown.
I like this kind of educational videos , Making the technology easier than they are .
Your simplicity of concepts is awesome!
ABSOLUTELY the best engineering videos! Couldn't agree more and very thankful to find you guys. Keep us the amazing work!
You guys do a great work, you summarize a whole semester class in a few minutes!
No he didn't ... he failed to explain how comparators work and another thing ... 60 Hz is 60 oscillations per second NOT 120 as he quoted
@@janinapalmer8368 120 oscillations is correct only because there employed 2 switches for the flow of current at a time
A whole semester was unsuccessfully spent in trying to learn what this this 7 minute video taught.
🤣
You guys make the best engineering videos, period!
Indeed!
fuzzygenius Thanks for the video
Actually I think they make the best engineering videos, frequency... Okay I'll see myself out
Yes
i dont think so - average value = 0 ? this is vid for noob... for Sin X T = 2Pi then is =0 when you count 3Pi it isnt = 0
This channel is insane, thank you so much for posting free educational videos like this! Love you
Amazing video sir! Thank you so much for your amazing efforts.
I humbly request you to make a video on Op-amps and their working.
Thank you once again.
Great materials, always good to revisit the basics. Thank you! Please keep it up!
you are the best engineers guys...hats off to you for the way u r explaining the concepts
Thanks for the video! I want to say that your videos are excellent at explaining engineering machines. Hope you keep doing this for a long time!
I have gone to school to learn about electrical systems in general, but if it’s only through reading books? My mind can not comprehend only with words.
But VISUAL learners understand with pictures or drawings. And with this video. I can now see how it all comes together.
Thank you for helping this ADHD electrician learn more about inverters and what role they play.
This is amazing... greatly blessed with the mind of making Modern inverters, awesome!
for a second I read "Introverts, How do they work?"
Alone
@@dewiz9596 forever
You set the benchmark of Quality
Um dos melhores canais do youtube. Obrigada!
0:56 The circuit is called H-Bridge, which has many applications, one of them is the full bridge inverter.
The full bridge inverter is a device that uses other circuits to control the H-Bridge as needed.
Full bridge and H-Bridge are synonymous words
@@Dawood4 Yes, H-Bridge is most certainly a full bridge, but not necessarily a full bridge inverter, the first time I applied the H-Bridge I used it as a full bridge driver for a stepper motor. The circuit on the video is just H-Bridge, applied as a full bridge power inverter (DC to AC converter), not a full bridge AC/AC converter, not a full bridge driver, not a full bridge anything else.
When you say that this circuit is a full-bridge, it doesn't make sense. A full-bridge what?
My point is, the H-Bridge is the circuit and the principle of work, the full-bridge is the application, whatever full-bridge that may be.
@@eneasota I mean to say, H-Bridge and full bridge have no difference in meaning. You can flip your usage of 'H-Bridge' and 'full bridge' and not change the meaning of anything. You can call it an H-Bridge inverter, or a full bridge inverter as they mean the same thing exactly. I think your dual usage of the word would confuse most people. Perhaps you mean 'Bridge Tied Load'
I LOVE THE WAY YOU GUYS EXPLAIN THE CONCEPT. KEEP GOING
Man books take forever to explain this. It's like reading my own report when I'm done explaining a point but have to hit the word count.
You guys took 7mins. Amazing!
short, clear and accurate my professor spend 4 hours to explain these things
God Bless you, thank you for this video, very well explained.
I wish they were simplifying things for us like this in school.
Хорошо объяснено, жаль что я незнаю английского, всё понимал по диограммам и схемам, спасибо вам !
finally, i understood how it works...........thanks for the video
Wonderful way of disseminating knowledge. Wonderful explanation. Wonderful narration. Wonderful video. Good job! I can only imagine how the world will be ten years from now with the ease of sharing ideas and knowledge. I hope I will live long to see this transformation. I hope the same knowledge can be used to develop safe and practical ways of mitigating the current global challenges. Thank you.
This was a really good supplemental on Inverters for me, thank you for creating the video! Additionally, I have found Toshiba has a fairly decent DC-AC document that also notes applications.
Can you share link to the document ?
You guys are doing fabulous job.. hat off to your effort .. Salute to your services for Engineering students ... May ALLAh bless you all. Ameen
This video was so amazing and very informative! Thank you!
Awesome. I was reading the material and my mind went blank, and it became stressful.
After watching your video, I once again am interested now to read the material again, and now I have a better appreciation of what I am learning when I see those formulas and waveforms.
what bookdid u read
THANKS A LOT, FOR THIS EXCELLENT EFFORT
great explanation
Hi how are you
I liked the H bridge demonstration, for the output, I have found a common mode power choke effective at smoothing with a non polarised capacitor on the output. It is very hard to get a perfect sine wave but it is good enough for most appliances which will simply re-regulate it
Absolute EXCELLENT video and description of the function of these inverter circuits!
Ok this was decent. But I would have liked more in depth on the smoothing to create the sinusoidal wave. Also where did the triangular wave come from?
Both can be generated using a uC or a DDS. The good thing is that they can be very low power signals. Control of them gives you the output frequency
Precisely. Not explained at all! Especially the triangular wave.
@@budavargas Thanks! Any vids on this topic?
When you connect a constant current source to a capacitor, it will output a rising voltage ramp. Discharging the capacitor with a constant current source causes a dropping ramp. Therefore making triangular waves easy. A constant current source can be made using a voltage comparator with negative feedback and because it's output voltage is inverted relative to input, you can make a loop that self-oscillates.
I really enjoyed the description of PWM. It was something I wanted to know for some time. I thought that mechanical, so called rotary converters, where used as inverters before the development of tubes or semiconductors. - I am sure nobody would use them this way currently anymore, but aren’t they still a viable option when it comes to convert DC to 50Hz or 60Hz AC?
well you can use them, but they are really inefficient... you are basically turning a dc motor, that acts as AC generator at the same time, so you would lose almost all of your available power to heat and magnetic losses before you even startet to use the AC Voltage.
@@dovos8572 electric motors of any sort have efficiencies in the 90% range, so two in 'series' will still have an efficiency above 80%...
@@Ironic1950 they only have that efficiency in their optimal load and depending on what kind of electric motor you have it can be less than 30% efficiency if you are at the wrong load point (not enough load and too much load).
It's a good collaboration with Indian brothers...
thank you very much for explaining how this kind of stuff works :)
This explained everything so well for a dummy like me! Thank you!
Sir thanks for making us understand in a good way. Now I can fully understand the function of the component needed for making inverter
i just understood a whole chapter from one video THANK YOU !!
i am an engineering student and I learn a lot from your channel.
thank you for your effort
plz make a video on compuer chips how they work from Logic gates to microprocessors.
Sabin Mathew doing a great job
Proud of you
#iit delhi
Kushal Sheth I'm also from iit
So, to generate a pure sine wave, you only need a pure sine wave, a triangular wave and a comparator... but, how do you get the pure sine wave to compare with the triangular one?? It's like "dehydrated water; to get water, just add water"...
Remember the comparison is done within a microcontroller/microprocessor then the output signal is sent to a driver which is in charge of switching ON/OFF the IGBTs
It's not just about getting a pure sine wave, since there is no real possibility to get it, there will always be deformations and noises, however minuscule they are, this type of inverter is not really an inverter, but a converter (the term inverter applies in many different ways in electrical and electronics engineering).
The goal is to have a signal on the input and achieve as nearly as possible sine wave with high power output.
The input can be of any type, sine, triangle, square, saw, analog or digitally modulated signal, PCM, PWM, FM, AM, PM, QAM or whatever type of modulation that can be used to create a sine wave without complicating the circuit unnecessarily that will guarantee a high power sine wave output.
If it's in a microcontroller, it's probably comparing values in 2 lookup tables (one for sine, one for triangle) based on the clock input.
You can generate a pure sinewave using a Wien bridge oscillator. You can even synthesize them using a microcontroller, DAC and low pass output filter.
This was simply mind-blowing. Thanks!
Guys, where the hell were you when i was undertaking my undergrad degree?? I could have used your help a lot. Thank you
Im a bit confused here. Where does the sine wave that we use to compare with the triangle wave come from ? Are we supposed to create a sine wave from the DC signal ?
You make it - with the amplitude and frequency you need, it's small signal. The circuit will follow in a "real power" path, thus recreating it from dc.
@@jupa7166 So to convert DC to AC, you first need an AC signal anyway. Doesn't make sense to me either. Why not amplify the AC signal you already have then ?
@@gigelfranaru You can call the process amplifying if You want :-) The thing is: input signal is microwatts, output signal is kilowatts.
@@jupa7166 i see. But the whole point is that you want to generate AC because you don't have it in the first place.
@@gigelfranaru Sure, of course, BUT generating small signal is really easy (one opamp or microcontroller or dsp plus a few parts), in case of a real power it is not that easy. Anyway, I'm pretty sure that modern designs skip that "comparator thingy" altogether and just use DSP which drive switches directly using some fancy algotithm, e.g. space vector modulation (which I have a hard time wrapping my head around, unfortunately...). So You are right, You can skip a step here and do it directly.
Nice video man... If you are reading this then make a video on.. how remote control works...
Remote control works on Duracell batteries
I doubt he will. Remote controllers are very simple. It either works by radio frequency or infrared (i suppose bluetooth as well but thats more software than hardware). Radio frequency being the simplest, just generates and radio frequency then the receiver just closes circuit when the frequency is received. Infrared essentially blinks a light towards a infrared sensor and decodes it as binary (I believe). Feel free to correct me if I'm mistaken, anyone.
Thank you for your compliments. I will have a detailed study of the remote control topic.
To generate sin wave we need... both sin wave AND triangular one. Does anybody see contradiction?
@@maxim5360 Man I don't know why ppl keep asking that same question. I'm sitting here with the ability to calculate and construct a sine wave with my bare hands. I'm pretty sure they can easily use a few semiconductor devices to create a signal. since a signal is all they need for reference.
An Explanation which even a child could understand! Great Job.
What an explanation..simply great.. you made the concept very clear . Animation is also wonderful. Thanks for ur efforts. Lots of love..
PWM pulses can be fed into an integrator (op-amp with resistive input at inverting junction and capacitive feedback), (also known as Miller integrator), then the choppy "staircase" sine-wave is smoothed out with a shunt capacitor to ground (low-pass filter) to remove high-frequency harmonics from the "staircase" wave.
Lovely video. I’m an inverter fanatic! What about creating a small signal sine-wave and using it to drive the mosfets in a push-pull configuration? Basically amplify a pure sine though a pre-amp and use fets to create a perfect high powered sine.
I think the problem is with power loss as you will be operating the mosfet in the ohmic region and dissipating much power as heat. OTOH PWM which drives the mosfet to full on and full off wastes far less energy.
I always had this doubt
Thanks for the video!
Thanks 🙏🏻🙏🏻🙏🏻🙏🏻🙏🏻🙏🏻 for free educational video ...
You live in my heart as a good man & teacher
The circuit is actually simple. Usually a microcontroller generates the pulses that turn on the h bridge (totem pole can be used instead) which then passes through a filter (capacitor and inductor) then to a transformer. Inverters without a transformer use a boost converter before the h bridge and switch at the output voltage. The microcontroller samples the output and adjusts the pulse widths to adjust voltage and power factor.
A pure sine wave inverter is basically a class D amplifier with a 60hz sine wave input.
In fact you could use a class D audio amp for car subwoofers and a transformer to create AC.
Make a video and we will see.
Thank you guys. I really appreciate it
You guys make me passed my quizzes
Nice, sir. I am also an elect engr having. An experience of 46 years. I also started a free education platform to share my knowledge & experience recently.
I did not understand all of details
But the way you explain it
And the tone of speaker's voice
Make anyone want to keep watching
i like how the education system in my country says the following: "you can only change from AC to DC not the opposite"
while everyone knows inverters are a thing
The reason for NOT simply producing high power sine wave is heat dissipation. When a transistor is "off" there is no current, hence no power dissipation; when it is fully "on" there is no voltage across it (well, not much) but lots of current; still not much dissipation as heat. The problem is between those states, you have a combination of high current and pretty substantial voltage drop, particularly if you have a reactive load such that max current hits at the same time as max voltage drop. A small 300 watt inverter will be consuming over 300 watts all by itself to deliver 300 watts; or an efficiency less than 50 percent.
Consequently it is crucial for the transistors or MOSFETS to be either fully ON or fully OFF and never half-on. MOSFETS are chosen for rapid switching, insulated gate and most of all, very low "on" resistance. This produces high efficiency and low heating of the inverter. But they can self-trigger if feeding a highly reactive load so that's a thing to watch out for. If that happens you'll know it because you will either blow a fuse (circuit breakers are too slow) or the MOSFET will simply explode.
Y'all are awsome, ill donate as soon as i get home, your supporting the same things i support and its free education, im 23 year old advanced programmer, and never even knew how a transistor works untill i found your vids. +rep
One of the best videos on Inverters here on TH-cam... :)))
I have watched three videos by Patrons and all of them have proven so brilliant. I salute the team. Keep going.
Hats off!!
wow man, this was super interesting, although I got lost in the part where you introduced the triangular shit, I loved it overall. thank you!
The narrator kinda skimmed over it, but the triangle wave is a key element for making pulses at varying widths to make this all possible. There is interesting study info on how pulse width modulation (PWM) works. The concept is pretty simple tho.
I'm looking to get into this field and this is by far the best video I have found on this topic
Thank you so much. This is such a beautiful explanation.
could you please make a similar video on multi-level inverters
Please support us at www.patreon.com/LearnEngineering . Your support keeps us going !
I am always sharing u r videos to what's app to see all my friend's and I will supp2
learn engineering ,
5.50
inductor used to smooth current.
capacitor smooths voltage.
resistor too smooths currents ?
(sorry for bad English)
Thank you for your supporting mentality :)
But I want you to stay, not go...
+karthi k It's true that inductors smooth current and capacitors smooth voltage, but resistors don't smooth current.
The voltage over a resistor is equal to the current through the resistor, multiplied by its resistance: u_R(t)=R*i_R(t) ( _ denotes that the following symbol is in subscript). Here you can see that if i changes, u changes immediately. u_R(t)=R*i_R(t) is known as the Constitutive equation of a resistor and describes the relation between the voltage over the resistor and the current flowing through it.
The current flowing through a capacitor on the other hand, is equal to the capacitance of the capacitor, multiplied by the change in voltage over the capacitor. i_C(t)=C*du_C(t)/dt (d denotes a change in the following variable. dy(t)/d(t) means the change in y(t) divided by the change in t, where dt approaches 0. This is known as the derivative of y(t)) Here you can see that the change in voltage over the capacitor is also equal to the current flowing through it, divided by its capacitance, so if you make the capacitor larger, while keeping the current flowing through it unchanged, the change in voltage will be smaller. This is what is meant by saying a capacitor resists change in voltage.
For the inductor the voltage over it is equal to the inductance multiplied by the change in current flowing through it, so its constitutive equation is u_L(t)=L*di(t)/dt. Here you can see that the same voltage over a large inductor gives a smaller change in current compared to when this voltage is applied over a small inductor.
So, we now know what the constitutive equations are for the resistor (u_R(t)=R*i_R(t) or u=R*i), the capacitor (i_C(t)=C*du_C(t)/dt or i=C*u' (prime notation ' is another way of noting the derivative.)) and the inductor (u_L(t)=L*di_L(t)/dt or u=L*i'), but how can we explain these formulae physically?
First we must know what current and voltage exactly are. Current is the movement of electrons through a material (even though we have defined the current to flow in the opposite direction of the flow of electrons. For our purposes this doesn't matter. You just have to flip the sign.) Voltage is the potential energy of the electrons. If you have a bunch of electrons or other negative charges at one spot, it has a negative voltage. this is because like charges repel, so the more negative charges you have at one spot, the more they want to go to a place with less negative charges. If you electrically connect a place with many electrons to a place with few electrons, electrons start to flow from the place with many electrons to the place with few electrons, until the electrons are approximately equally spaced.
Let's first use this to analyze the capacitor. The most basic capacitor is made of 2 opposing metal plates, separated by an insulative barrier, for example air. Let's apply a constant flow of electrons from one plate of the capacitor to the other. Since the electrons can't go anywhere other than the plates (They can't flow through the air.), the electrons will accumulate at one plate (decreasing the voltage) and the other plate will lose electrons (increasing the voltage), so with a constant flow, the voltage across the capacitor increases linearly. This explains the constitutive equation of the capacitor.
What about the inductor? Let’s take an inductor and increase the current flowing through it. This will generate a magnetic field, storing the potential energy (voltage) of the electrons moving through the inductor in the magnetic field. If the potential energy of the electrons is zero, the magnetic field is unchanging and the voltage is zero. If the current were to decrease, the magnetic field breaks down, releasing the potential energy, causing a negative voltage, keeping the current up. In other words, an increase in current causes a positive voltage and a decrease in current causes a negative voltage.
A resistor also has a current flowing through it, just like and inductor, but instead of generating a magnetic field, the energy gets dissipated in the form of heat, so a constant current means potential energy is constantly dissipated in the form of heat, causing a constant voltage. I hope this helps you in understanding why capacitors, inductors and resistors behave the way they do.
-Dehim
You guys are best 😍.Keep making such awesome videos.
Very well explained - step by step - I love your channel, keep up the good work !
Ah yes, I frequently observe a hum when I power my overhead fans using square wave power. What a relatable anecdote!
😂
Thanks for the video.
I would just like to clarify a thing at 0:37.
Periodic waves, even though not at 50% duty cycle.. are still considered AC as long as the currents go from one polarity to other.
Thank you Lesics for your graphical presentation of complex topics of invisible functions used in electronics circuitry.
Good voiceover.
Best wishes. From Pakistan.
Just amazing explanation 👌❤️ love it
how about the 3 phase square(ish?) wave AC (average: 0) electromagnetic motor? (BLDC)
It is not bldc motor it is 3 phase dc motor
Video glossed over key details - the generation of (how?) triangular and sine waves into the comparators.
i thought the same thing.. if u have a sine wave into the comparitor, whats the point, u already got it
@@bubbahogg-buga4613 the sine wave going in the comparator is having an amplitude of not more than 12V, while the sine wave coming out of inverter has a magnitude of 120 or 240 volts depending on where you live. With the help of function generator you can generate the required sine and triangular wave.
It is a Great video abt Inverters I have happened to watch. THANK YOU
The best explanation I have seen after scouring all over the internet. Thanks a lot for the video.
Excuse me, on minute 3:30 where do you get the sine wave to compare with triangle wave because it is what we want to produce? Thank you!
HAHAHAHAH! That's exactly my question. Why struggle to produce something that we already have in the first place?
Yeah my doubt is also the same..
How to make these types of animations .. which software do you using to create these videos ...
They have answered that in another video. They use Blender.
employment & education blender.org pm if i can help ;)
How does it work? Ask an engineer! Perfect explanation, right out of the classroom!
thanks for this video. cleared all my doubts instantly. this is why you have gained such great followers indeed.
I watch your all videos
Where do you get the input waveforms for the comparators from? Where do the triangle and sine come from?
Pepe You can make these signals using active oscillators (operational amplifier with RLC elements) , or you can make it with a little program (coding a micro controller) that makes a sine or triangular wave in binary value and then you can send this signals to a DAC
good point
Awesome video. Makes sense. (+1)
Todays way of learning is much more efficient than it was yesterday.
And it's actually pretty simple. Once you understand what Mosfets and OpAmps do.
MOS : Vgs(th)
OpAmp: in in out.
Lol.
Capacitors: have a charging/discharging curve.
Inductors: have a charging and discharging curve opposite of capacitors.
etc.
Thanks again for a splendid explanation, I love it and will keep reading, kind regards
At 3:30 you introduce triangular waves. Where do they come from. At the same timestamp you say the triangular waves are compared with a sine wave. Where does the sine wave come from? Wasn't it the whole point to create a sine wave? And now you just suddenly already have one? To create one? Can you please explain that more comprehensibly?
After watching vedio I just came to the comment section to get cleared from this doubt, by seeing some of the comments like "gr8 vedio" I had really got tensed 😅
Ok, lemme give it a try,
Generating a low power sine wave is easy, generating a high power sine wave, efficiently is harder. Now, triangle waves are the classic way of generating a PWM signal because when 'comparated' against another voltage the peaks of the triangles will translate to a thinner duty cycle in the squarish PWM output. Think of a mountain in the middle of the ocean, as the water level rises the base of the mountain gets smaller. Thus with a simple, moving voltage we can change the duty cycle; Now instead of a stable voltage we substitute with the small sine wave, and now your PWM's average power will mimic that of a sinewave. This signal is then sent to the transistors who switch the main, large power. This is done this way because if you drive transistors in the "linear region" they will dissipate a lot of heat, that is to say they are much more efficient when you run them fully on or fully off. Does this make any sense?
the best channel of electrical engineering ever !
I can only suggest u also EEVblog and ElectroBOOM
I've watched this video twice already. This time it finally clicked! Thank You!
Drizzy Williams
Thank you for this highly informative video. Looking forward to more such videos. Thank you once again and my best wishes.
Please make a video about how circuit breakers work
3:30 So where does the sine waves that are compared to triangular waves come from?
Those are logic units. That sine wave is just an equation in logic.
Fourier transform
Or maybe from oscillator source like a cristal?
@@kneifelimre2517 A crystal doesn't produce a sine wave, but a weird-shaped one. You have to do conversion, which I want to learn how. If I rephrase my question, our goal here is to obtain some sine wave, and the way to do it is to have some other sine wave first?
Your videos have genuine explanation
Only your video make me understand how sine wave inverters work! Thanks mate!
Wait, the sine wave that is fed to the comparators, where does it come from?
If the sine wave doesn't need to provide actual power, only be there as a reference, is quite easy to make an accurate one combining a few Op-Amps and capacitors, or using pure PWM with higher switching frequency and a sine wave table in software.... The need for comparators came when you have a load that change over time, a fixed solutions would over and under voltage the output.
Yeah it seemed like this whole complicated apparatus to make sine waves was was unnecesary since it relied on sine waves to work lol.
They should have at least mentioned that. Else it looks like everything is pointless or the solution appeared from under the sleeve.
finally a smart guy
but how EXACTLY?
Sine wave is easy to produce (a $5 walkie-talkie can do that). It is hard to produce a *high-amplitude* sine wave capable of giving enough power to accelerate a Tesla to 60mph in 3 sec.
1:43 It's 60Hz but I think that in Europe it's all 50Hz
True that, we europeans have to deal with 50hz, so everything will run 20% slower.
Finally. Someone has what I am looking for. Thank you so much!
this gave lot of life to the imagination so far. was simple and clear