Stefania Neicu
  • 3 months ago
Transcript
00:00Hello everyone, welcome to this training program, today we will do a two-dimensional exercise in the photovoltaic system, this program will be presented to you by Samuel Terpil-Gesserit, our different training manuals.
00:25You have on Amazon the book Photovoltaic System for Beginners, its English version Photovoltaic System for Beginners, you have understand Photovoltaic, its English version Photovoltaic, you have Photovoltaic Counting System for Beginners, you have the book Become Photovoltaic Technician, which is one of the main components of our training.
00:52You will find this training in the book of more detailed explanations of what we are going to see today.
01:02Suppose you have a table to complete, here we have already done the calculations, but suppose you went to a client and that you have met the needs such as the number of TVs, the number of fridges, the number of computers, the number of fans and maybe a solar pump that the client wants to install at home.
01:30Let's say a pump that he has at home and that he needs to power the solar energy.
01:35You have tried to verify, you have seen the characteristics such as power, you have heard about the time that each of these devices can run.
01:47You have developed this table that allows you to calculate your power balance.
01:53So now we're going to try to see how to do the different calculations to get total energy.
02:01If you have watched the previous videos, you probably already know how it works.
02:06But here we are going to make a little history reminder to be sure that we are well understood.
02:14To obtain total power, we have done the number of equipment times the power of this equipment, which gave us the total power of each equipment.
02:27Now to have total energy, we have done this power that we have just obtained multiplied by the time that these equipment will run, which gives us the energy.
02:39Hence its unit in Watt hours.
02:48Now after obtaining all these results, we do the sum of the powers to obtain the total power.
02:54And also for the energy, we do the sum of these different energies, which allows us to obtain the total energy.
03:06And we have separated the day needs from the night needs.
03:11The concept is this.
03:14When we talk about day needs, we take into account devices that will work during the day and devices that will work at night.
03:23In some contexts, the bulbs work during the day. In other contexts, they don't.
03:28That's why we can't affect the consumption of equipment that doesn't work during the day.
03:37Otherwise, it will try to boost our efficiency.
03:41To be more precise, sometimes it is the number of panels that can be higher than the number of batteries, because of the fact that some equipment, perhaps too much equipment, will work during the day compared to some equipment at night.
03:55In our case, the pump will work during the day, we will say at sunset, and at night it will not work.
04:04During the day, the bulbs will not be turned on.
04:07On the other hand, at night, the bulbs will be turned on.
04:10So, we make this small differentiation and then we manage to obtain the results that we have there.
04:18Now, when we have finished separating day needs, night needs, the question for us is to gather the different energies.
04:27The energies, since it is day and night, the energies are combined to obtain the final energy.
04:33So, in terms of power, we are not going to add different powers.
04:39We will simply focus on the equipment.
04:44In fact, we will review all the equipment that is in the house and we will do the sum of the powers of all these equipment.
04:52We will not take into account that there are certain equipment that works during the day and that is still found at night, and then we add the power of those of the day and those of the night.
05:01We just feel that we have the TV, we have the fridge, we have the computers, we have the fans, we have a pump, we have the bulbs, and we look.
05:11We have how many TVs, and so on, and then we do the sum of these different powers to obtain the total power of the house.
05:21Once we have these elements, we can start our calculations.
05:26By the way, here on your left, you will find the formulas that we used for these calculations.
05:35Ok, we will continue.
05:43Now we are going to calculate the photovoltaic energy.
05:46For someone who is a beginner, photovoltaic energy is the energy that comes from the panels.
05:51The energy that the panels will produce.
05:54We already have the energy that the house needs to function.
05:59Now we are going to look for the energy that the panels must produce to make this energy satisfied, this energy of the house.
06:06The energy produced is therefore equal to the total energy that we have just obtained divided by a certain coefficient k.
06:13This coefficient k will take into account a lot of variations.
06:18So, the 10,140 that we obtained will be divided by 0.7.
06:25As I told you, there are very important details that we must take into account.
06:31We will go back a little.
06:34At this level, you see that there are the total energy needs of the day and the total energy needs of the night.
06:42The total energy needs of the day will be used to calculate...
06:48No, sorry.
06:51The total energy will be used to calculate the number of panels.
06:56Since the panels will charge the batteries at the same time and at the same time run the equipment that will run during the day.
07:02So, we are going to take 10,140 Wh to calculate the energy needs necessary for the panels.
07:12On the other hand, we are going to use the needs of the night only to calculate the number of batteries.
07:18So, with this way of dimensioning, we know that we have the number of panels sufficient to power the equipment that will run during the day
07:26and that we also have a sufficient number of panels to charge the batteries at the same time as they power the equipment that will run during the night.
07:37This is the advantage of this method of dimensioning.
07:40There are other methods that you will find in our previous videos.
07:45So, we can continue.
07:50I was saying that to calculate the energy at the level of the panels, we are going to do the total energy divided by K.
07:59This will allow us to obtain...
08:01In our case, it is 0.7 K.
08:03To have more explanation, you will see the previous videos where we tried to bring some elements.
08:09And for more details, you will go back to our training manuals where you will find explanations a little more in-depth.
08:20Here, we are going to calculate the power of the generator.
08:22We already have the energy of the generator, but we want to have the power of the generator.
08:28To have the power of the generator, we are going to divide the energy that we have just obtained by irradiation.
08:39It is therefore a question for you to know the irradiation that is in the area where you are going to install your solar system.
08:45First, you should know that irradiation is a variable phenomenon.
08:49We cannot say that irradiation is not stable.
08:52In one day, we can observe more than 1,001 variations of irradiation.
08:57Researchers have made an estimate of the average irradiation in a period.
09:05That is why we are going to talk about irradiation during a month, irradiation during a year.
09:09The average irradiation, in fact.
09:11They have added all the different irradiations during the year.
09:14They first did the average of the day, maybe, the average of the week, the average of the month.
09:20And later, the average of the year of each area, of each city, of each village.
09:27If you want to install your system in a village, you are going to look for the average irradiation of this village.
09:32And that's what you're going to put at this level.
09:35You are not going to take the 3.8 that I just put.
09:38You are going to look on the net for the value of the irradiation of the area where you are.
09:44We will continue.
09:46And from there, you are going to get the power of the generator.
09:50Later, you will be able to calculate the number of photovoltaic panels you need to realize your system.
09:57And the formula to calculate the number of panels,
10:00you just have to do the power of the generator divided by the power of a panel.
10:06This implies that at this level, you have already made the choice of a panel on the market.
10:15You are going to make the choice of the panel.
10:17You can take panels 260, 360.
10:20It depends on the context in which you are.
10:22In this particular exercise, we are not going to deal with which type of panel to take for this type of installation.
10:28These are questions that have already been addressed, which we will perhaps address again later.
10:32If you ask questions, of course, after having checked and viewed the video.
10:39After calculation, we found 14.66 modules.
10:47And we chose to take 16 modules.
10:50The choice of 16 modules, in principle, takes into account the type of installation that we are going to do after.
10:56If we decided to connect the panels for a 48V system, it is justified that we are going to take 16 modules.
11:04Because we are going to make branches of 4 modules in parallel.
11:12Assuming, of course, that we would have chosen to take 4 modules in parallel.
11:18It would make it easier for us to make these branches.
11:23But since we have chosen a panel of 260 and we say that a panel of 260,
11:28its voltage will reach 36V and we want to start in a 48V system.
11:33At this level, we will be able to say that we are going to make branches of 2 modules.
11:38Generally, when you get the characteristics of a panel with a comma,
11:44you may find 14.66, it is recommended to increase.
11:49Instead of taking 15 modules, which will make an odd number,
11:53it is recommended to take an even number.
11:56This is the other reason why we take 16 modules.
12:00In some contexts, we will find ourselves where we want to put 4 modules in parallel, in series rather.
12:06And there, we will be forced to go to 16.
12:09If in another context, we wanted to put all the modules in parallel,
12:13there we may have to take 15.
12:17But once there is the notion of series rather, the number must be even.
12:26Calculate the energy of the photovoltaic generator.
12:30Calculate the energy of the photovoltaic generator.
12:34Calculate the energy of the photovoltaic generator.
12:44Now we will be interested in the choice of the charge controller.
12:48Determine the voltage of the system.
12:51Determine the voltage of the system.
12:54To determine the voltage of the system,
12:56there are methods already established by certain brand designers
13:01and others by certain researchers.
13:04We will focus on this one,
13:07which is certainly not the only one.
13:10There are so many methods.
13:12Surely you have already found another method,
13:15and you meet a new one, don't get confused.
13:18You can choose the one you want to use,
13:21and it will work for your installation.
13:24For us, we have a certain voltage range of panels.
13:29If you have found the power of the panels
13:32ranging from 2,000 W to 10,000 W,
13:35you are told that the system you will choose will be 48 V.
13:42And in our case,
13:45it is this voltage range that we will take
13:48because we have found a power of the generator
13:51which is equal to 4,160 W.
13:54Now there is the question for us to calculate the current of the charge controller.
14:00To calculate the current of the charge controller,
14:03IC, which we have called IC,
14:05we will have to do in the power of the generator that we just found
14:08is divided by the maximum voltage of the system.
14:11And when we talk about the maximum voltage of the system,
14:14we are talking about the voltage ...
14:19If you watch the previous videos, you will see that
14:22we said that when we have a system voltage of 48 V,
14:27the maximum voltage of the system will tend towards 60 V.
14:33Or 72, it really depends on the type of panel you have with you.
14:37But now, there is a very important parameter that must be noted.
14:41It is that I could have even put 150 V at this level.
14:46There, it would depend now if I already know the type of charge controller that I will use,
14:51if it is MPPT or PWM.
14:54I think addressing this question here may be a bit confusing,
14:59so we will also come back to this detail in the next videos.
15:06So here, we will simply focus on what we had already learned previously,
15:12that when the system voltage is 48 V,
15:17the system voltage range will be between 60 to 72 V.
15:24Now, the other detail that I bring up is that
15:28it depends on the type of charge controller we choose.
15:31This is a PWM charge controller.
15:34This is an MPPT charge controller.
15:37We will continue our exercise.
15:41We have obtained a value of 83.2 A.
15:47When we get such a result, we have to go back to the market.
15:50Are there charge controllers of 83.2 A?
15:55No.
15:56So we are looking for the highest charge controller that meets these characteristics.
16:02In fact, that is close to these characteristics,
16:04but generally, as I told you previously, we have to increase.
16:08In this case, we will not take a 100 A charge controller,
16:12as some people already said.
16:14We will rather try to split our system into two groups.
16:19We will take two 60 A charge controllers.
16:26Let's assume that I am an equipment supplier.
16:30We have taken the characteristics and we end up with this result of 83.2 A.
16:36We realize that there are solutions in 80 A,
16:40there are solutions in 100 A,
16:43and there are solutions in 120 A.
16:44Now we ask ourselves the question,
16:45can I find a 100 A charge controller on the market?
16:56If there are no 100 A charge controllers in my country,
17:00it means that if this brand does not deliver this type of charge controller in my country,
17:05instead of wanting to import it, it is better to find a more appropriate solution.
17:09The most appropriate solution in our context is to take two charge controllers,
17:14knowing that our modules that we have found, we will divide them in two.
17:18We have 4,160 watts that we will divide in two
17:23and we will make branches of 260.
17:26In fact, branches with the result that we will find
17:29and we will know how to connect for the rest.
17:33This is a practical phase, so we will not go into this detail.
17:45It is now a question of making the choice of the battery.
17:49Calculate the capacity of the battery park.
17:53The capacity of the battery park is equal to the total energy per night.
17:57As I told you when we talked about the evaluation of needs in terms of energy,
18:02we talked about total energy per night
18:05and we will multiply it by the number of days we want to see the system work.
18:09If we have enough means and we want to see our system work for 2 days, 3 days, 4 days,
18:13we will affect this number of days as a coefficient.
18:18And then we will divide by some coefficients that allow the battery number to hold.
18:24Since there are losses when the battery does not discharge 100%,
18:28and so on, there are many phenomena that occur.
18:31So there are coefficients that we will affect such as 0.9, 0.97
18:35and as soon as there is the discharge coefficient that I mentioned earlier,
18:39it will not discharge 100%, it may discharge 70%, maybe 80%.
18:44And then, the system voltage.
18:51So, from there we get the capacity of the battery park.
18:55You are probably wondering, for such a large system,
18:58how is the capacity of the battery so low?
19:01At this level, you have the capacity of the battery park
19:06and not the capacity that concerns the total number of batteries that we will have.
19:11This is why in the following, you will see that we will continue to calculate
19:15and now obtain the capacity of the entire battery.
19:22Because there is what we call the capacity of the battery park.
19:25That's what you just got.
19:27And now, depending on the number of batteries,
19:30we can estimate the capacity of the battery park.
19:35I don't know how to say it.
19:36Maybe I don't know if you understood me.
19:39The capacity of the battery park is obtained by dividing by the system voltage.
19:44But if you want to have the number of batteries,
19:46the capacity that requires the number of batteries,
19:49you will divide by the voltage of a battery.
19:54And there you get directly the capacity of the battery park
19:57according to the number of batteries.
20:01And to go up the slope and find the number of batteries,
20:04here is the formula that you will apply after finding the capacity of the battery park.
20:09You will multiply by the system voltage
20:11and divide by the voltage of a battery
20:14or the capacity of the battery that you have chosen on the market.
20:20In the 200, it corresponds to the capacity of the battery that you have chosen on the market.
20:27From there, we find that we have found 4 batteries of 200 Ah
20:35that can hold our equipment that will work at night.
20:42And remember that here we have taken a single day of autonomy.
20:47We said that our battery will work for 12 hours.
20:55And when we say 12 hours, it's a bit exaggerated
20:58because if you go back to the power balance,
21:00you will see that some equipment will work for 6 hours,
21:04some equipment will work for 8 hours.
21:06That's what it's about.
21:11Now we try to see how many batteries are in parallel,
21:15in series, everything that goes with it.
21:17And at this level, it's the number of batteries in series,
21:20it's the voltage of the system divided by the voltage of a battery,
21:23the number of batteries in parallel,
21:25that is to say the number of batteries that we obtained divided by the number of batteries in series.
21:29So that's a bit what you have to do.
21:34Now let's see how to choose the voltage converter.
21:38Here we go back to the power balance.
21:40As I told you, to obtain the total power of the equipment,
21:43this is what you have to do.
21:45This value that we have obtained, we are going to divide it by the cos phi.
21:51And when we have divided it by the cos phi,
21:54we will find the value of the power that was in volts in pairs,
21:57which will allow us to make our choice of converter on the market.
22:02Now, it may happen that by doing your dimensioning,
22:07you have used equipment that requires a strong power at startup.
22:13Since there are equipment that requires a strong power at startup,
22:17you are going to use a certain coefficient that will allow you to secure your converter.
22:22Since these equipment, when they start, sometimes they are perhaps at 100 watts,
22:26at startup they go up to 200, 300, 400 watts.
22:30For that, you have to multiply the power you have obtained by 2 to protect your system.
22:36In other cases, you will see that I used 1.5, 1.2,
22:40all that really depends on the amount of equipment that will require a power at startup.
22:46It also takes into account the fact that it can happen that all these equipment are connected at the same time.
22:52You have to make sure to secure your converter as much as possible in case it burns.
23:01So, from a catalog, you make the choice.
23:04You have found 2437.5 volts in pairs.
23:08When you look at the market, what corresponds to the best?
23:11Do not forget that the voltage of the system is 48 volts.
23:15So, by making your choice, you have to take into account the voltage of the system.
23:22The cable section between the generator and the regulator.
23:27Here, we will try to see how the cable sections are calculated.
23:33You calculate the cable section.
23:35It now depends on where we are located.
23:38Usually, in the cable section, we will leave the panel to go to the charge controller.
23:44If it is at this level, we will see how it goes.
23:49You will first calculate the intensity.
23:51What intensity?
23:52The intensity that will leave the photovoltaic generator and certainly arrive at the charge controller.
23:59You will take the power of the generator divided by the voltage of the system.
24:05We have found about 16 panels.
24:07Here, we use 8 panels to calculate the power of the generator
24:11because we will make two panel branches.
24:17A branch for a 60A controller and another for a 60A controller.
24:25We will divide by the voltage of the system, which gives us the value you see on the screen, 43.33A.
24:34Then, we will calculate the voltage drop.
24:37To have this voltage drop, we will use the voltage of the system multiplied by 0.02.
24:43This value is usually used when we use copper conductors, 0.02.
24:50We will obtain this result.
24:53We will arrive at this level.
24:56We will divide by the intensity we have found here.
25:00This is to find the resistance of the cable.
25:03We will find 0.96, which we will divide by 43.33, which gives us the resistance of the cable.
25:10From this level, anyone who has done the technique or the subsidiary that it is,
25:16will know that to calculate the section of the cable, it is much more those who have done the technique.
25:24To calculate the section of the cable, we will do Rho times 2L divided by R.
25:30This is usually the formula you find.
25:32The elements that we have calculated above allow us to apply this formula,
25:36knowing that Rho, which is the resistance, the resistivity of the cable,
25:41is equal to 1.6 times 10 to the power of minus 8 when we talk about copper cables.
25:47We will therefore multiply it by 2, we will multiply it by 5,
25:51and we will divide it by this value that we have obtained.
25:565 is the length of the cable.
25:58This means that to calculate the section of the cable, you must already know the size that the cable will have.
26:055 is therefore this cable size.
26:092 is the value that is in the formula.
26:12Sorry, I stretched a little.
26:14This is the value that is in the formula.
26:19Rho is also in the formula, divided by R, which is the resistance of the cable.
26:26From there, we find a value of 7.27 times 10 to the power of minus 6 m².
26:31We will convert it to mm².
26:34From there, we get 10 mm² because we rounded.
26:45We will continue the choice of the cable section.
26:50This time, we leave the box, since we have already arrived at the regulator's box.
26:56We will start from the box to go to the regulator.
27:00Sorry, previously, we calculated the section of the cable leaving the generator for a certain box,
27:07in case we are going to use a connection box for these different modules.
27:15In the opposite case, it will be directly driven to the regulator.
27:19This is why at this level, it is true that we have prepared some calculations,
27:22but we advise you to use the same cable section to continue from the box to the regulator.
27:29It's the same cable.
27:34We continue the cable section between the battery park and the wave.
27:40At this level, if you have found 10 mm², it is already good.
27:43You can continue like this with the same value, but if not,
27:46you can also continue by performing calculations as we explained previously.
27:50This time, you will use the power of the wave.
27:55You will pay attention to the system to obtain the intensity.
28:01You will continue the operations as before and you will get the results.
28:06It's so satisfying.
28:10Now, we are going to talk about protection devices.
28:13In our context, since we are not going to touch the 220V side,
28:18we will stay on the side.
28:20On our solar system, we advise you to use, in this case,
28:24DPMs for the protection of your system.
28:28You will certainly find videos where we show you where to place these generators
28:33and where to place the paraffin in your photovoltaic installation.
28:37In this context, in this particular exercise,
28:40we saw the need to use 5 DPMs.
28:46In the next figure, you will see where each DPM can be used.
28:54The wiring diagram.
28:56At this level, you can see that we have placed a DPM that will protect
29:02the first charge controller,
29:05the DPM that will protect the second charge controller,
29:11the DPM that will protect the batteries in relation to the wave,
29:16the wave in relation to the battery, all that.
29:19And the DPM that will also protect the batteries
29:24when the charge controller will come to charge these batteries.
29:28It's a bit like that.
29:30This is the security.
29:31You make sure that the security is maximum.
29:33Now, the paraffin will simply come to protect your system
29:37against lightning and everything that goes with it.
29:40So, this is roughly the wiring diagram of your system.
29:45That's all for today.
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29:51to allow other people to benefit from this content
29:54that we put in the history section
29:56where we contribute to your training.
30:00See you soon for the next one.
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