Today, the discussion is about simulating Maximum Power Point Tracking
(MPPT) using the boost converter in matlab. The Perturb & Observe algorithm is used
for the MPPT implementation. There are two primary ways we can
implement MPPT, in a batch converter. First we feel the photovoltaic
and current, and using these values we apply the MPPT.
The MPPT output will directly give the required percentage of work to
generate the PWM. This value is compared
to the carrier signal and given to the MOSFET gate station. In the second method,
similar to the previous method, we first feel the voltage and current and apply the MPPT.
But here instead of the working ratio, we get the reference voltage as the output.
This reference voltage compared with the actual photovoltaic voltage to find the fault.
This error is then fed to the PI controller. The output of the PI controller will give the
required operating ratio for PWM generation.
This value is compared to the carrier signal and given
to the MOSFET gate station.
Compared to the first method, this method will give you
better mppt tracking performance since it has
a closed loop control mechanism. This method is used in simulation, which
I will explain. This is the flowchart of the MPPT algorithm
that we will now simulate. You can pause the video and try to
understand it. Now I will show you how I designed
the boost converter. First I will present the specifications of the
circuit. The solar operating voltage ranges from 250V to 350V.
The input current divided by the input voltage.
This is 400 amps.
So the current ripple is 5 percent of 400 amps.
This is 20 amps. Now the voltage ripple is 1 percentage of the output voltage, i.e. 6 volts.
The output current is given by the rated power divided by the output voltage.
That will give 166 amps. Now we will calculate the inductance and capacitance of the
boost transformer. The equation I'm using here
is taken from the power electronics textbook by muhammad H rashid,
the value of inductance is given by, L equals v input at v output minus v
input divided by fsw to delta i to v output
which will give 1.45 millihenry. The capacitance value is given by c
equal to i output in v output minus v input divided by
fsw to delta v to v output. which gives 3227 microfarads.
Now we open MATLAB and start the simulation.
First we add the PV array. Set the number of strings and parallel strings
. This is the MPP voltage and maximum power at
1000 watts per square meter radiated.
These are the same as the radiation values of 500 watts per
square meter. This is for a radiation of 100 watts per square meter
. The open circuit voltage is 363 volts. Set radiation 1000 and temperature 25 degrees. The name of the PV voltage and current. Connect the DC input capacitor.
Put in some random values. 1000 microfarads is used here . This is the trigger for reinforcement. Set
the design value of 1.45 mH. Now connect the IGBT.
Now connect the diode.
Connect the filter capacitor. Set the designed value of 3227
microfarad. Connect the load at the output. Set
its value to 2 ohms. Connect the unit delay block. Now I start writing the MPPT code. So that completes the MPPT code. Now add the total block. Connect the PID controller. Set the values of Kp and Ki. Add a repeating sequence.
Set the switching frequency and carrier signal amplitude. This block displays the energy generated
by the solar PV array. Set the simulation in discrete mode
and the sampling time is 1 minute. Now we run the simulation. There is a bug in the mppt code so I will
correct that. This message must be in uppercase. Here you can see the energy generated by
solar panels. 1000 irradiation maximum power
100 kW. So we'll see if it gets to that point. As you can see, the power has reached 100
kilowatts. So the mppt is working fine. The same can be displayed in the range as well.
Now we will see how mppt responds,
when we change the irradiation while running. Convert radiation to 500 watts
per square meter. The corresponding MPPT point is 500
kW. So the force must reach this value. Now the force has changed to the new MPPT point . Now I will try a different irradiation. The power reached 60 kW,
which is a mpp point for 600 radiation. Now I'm going to change the radiation to 1000.
So the power should be up to 100 kW.
Let's see if that happens. So the power has reached 100 kW. Now we will see how it responds
to temperature change. Since I increased the temperature,
the power decreased. When I return to the
previous temperature, the power also returns to the previous value. This is the end of this offer.
thanks for watching..