Design and Development of solar based MPPT Inverter

In our Project we design a buck Boost solar based inverter which buck and boost the voltages according to the requirement of the components.in this we are making a complete home solution which completely runs all components likewise.we are using two 436 watts solar Panels and two large batterie

Project Title

Design and Development of solar based MPPT Inverter

Project Area of Specialization

Electrical/Electronic Engineering

Project Summary

In our Project we design a buck Boost solar based inverter which buck and boost the voltages according to the requirement of the components.in this we are making a complete home solution which completely runs all components likewise.we are using two 436 watts solar Panels and two large batteries our whiole system is of 700-730 watts power .MPPT is a type of solar based buckboost converter. It is used in solar applications to provide the best possible power by maximizing the power transfer to the load and minimizing the power transfer to the battery.MPPT works by tracking maximum power point and adjusting output voltage accordingly. This means that MPPT will always be delivering as much power as possible to the load, while also charging up a battery if one is present.solar panels are more effective way of generating energy from sun energy. They’re not the maximum, however they may be the maximum convenient to apply on a small to medium. Photo Voltaic Cell (PV Cell) are more often than not crafted from silicon (though some non-silicon based totally methods are being developed). Just like that utilized in PCs. At the same time as silicon itself is a completely abundant material the manufacture of sun cells needs to be in a completely in smooth surrounding. This reason manufacturing price to be excessive.
A Photo Voltaic Cell (PV Cell) is created from 2 kind of silicon which is whilst hit by the mean of solar power generate a potential difference across the panel and if related to circuit.
In most instances, some of solar panels might be linked collectively to shape an array. Solar panel of comparable kind can be linked in series to provide a better voltage. 12V solar panel can be linked in series to provide 24V. Normally some of solar panels might be linked in parallel to provide an accelerated current.

Project Objectives

The MPPT controller allows a panel array to be of higher voltage than the battery bank. This is relevant for areas with low irradiation or during winter with fewer hours of sunlight.They provide an increase in charging efficiency up to 30% compared to PWMGreater flexibility for system growth. This is relevant for commercial establishmentsThey typically come with higher warranty periods than the PWM typeMPPT controllers are more expensive, but give greater flexibility in terms of number of panels. The voltage from the PV module will drop down, with a corresponding increase in the current amperage, to match the battery bank. An increase in amperage will lead to faster recharge. These solar charge controllers will automatically adjust as per the P = V x A equation. As a result, you will get more power to charge the battery and there will be no loss, unlike the PWM.

Buck-boost converters offer a more efficient solution with fewer, smaller external components. They are able to both step-up or step-down voltages using this minimal number of components while also offering a lower operating duty cycle and higher efficiency across a wide range of input and output voltages. Buck-boost converters are also a lot less expensive when compared to other converters.They are not perfect solutions, though; there are some drawbacks. For example, they cannot achieve high gain because efficiency is too poor for it (i.e. very small or very large duty cycle only – no in-between). There is also no isolation from the input to output side, rendering it unsuitable for certain applications.

Solar thermal energy, also known as thermosolar power, uses the sun’s energy to produce heat, which is then used as an energy source at the domestic level (to heat up one’s house, cook or for personal hygiene) as well as at an industrial level, transforming this energy into mechanical energy and from this obtaining electrical energy.

Solar thermal energy provides heat using mirrors so that the sun’s rays can be concentrated into a receptor and reach temperatures of up to 1000°C. The heat is then used to warm up a liquid which generates vapour and moves a turbine which produces electricity. Solar thermal collectors use panels or mirrors to absorb and concentrate solar heat, transfer it to a liquid and conduct it through tubes for its use in buildings or facilities or also for the production of solar thermoelectric energy.

Project Implementation Method

 As discuss above P&O algorithm, used to track MPP of the panels. The algorithm measure the values of voltage and current and then calculate the power of the system at that point that perturb the voltages and observe the maximum power point. Figure 11 shows the P-V curves of the panels.This is conventional P&O algorithm technique which is measure the input voltages and current values and then calculate the power. We bring changes in this technique, finding the maximum power point which is measure the output current along the duty cycle and then perturb current and duty cycle values are observe maximum power point.Now the question arise is that how we know that we achieved maximum power point (MPP). The answer is when the change in dIb and dD is zero our MPP is achieved. Below table will summarize the functionality of the algorithm.In start work with sensing the battery current and stores if in some variable. Then calculation the difference between the value of battery current with previous value and duty cycle value with previous value. If the difference of both values is greater than 0 then increase in duty cycle and vice versa. Similarly if the difference of battery current (dIb) is greater than 0 and difference of duty cycle dD is less than 0 then duty cycle is decreased and vice versa.Our solar panel specification is 450 watts. So our converter should be capable of handling 876 watt. We should design our converter for double the rating which is to handle i.e. we will design a converter able to handle 1000 watts

Benefits of the Project

MPPT technology has become very popular in solar electronics and is, in fact, the de-facto standard for on-grid / string inverters.

MPPT stands for Maximum Power Point Tracking.MPPT is basically an algorithm and implemented through a combination of software and electronics hardware in any inverter or solar controller.It helps in ensuring that the output from the solar panel or array or solar string is at it’s peak / maximum.  This is done by a continuous power tracking methodology so as to settle at the most optimal power point from the solar panels.The Maximum power of a solar module varies with solar radiation, ambient temperature and cell temperature.   Solar cells have a complex relationship between temperature and total resistance that produces a non-linear output efficiency based on the I-V curve. The objective of MPPT system is to sample the output of the PV modules and apply the proper resistance to obtain maximum power for any given solar radiation and overall environmental conditions.

When a load is directly connected to the solar panel, the operating point of the panel will rarely be at peak power. The impedance seen by the panel derives the operating point of the solar panel. Thus by varying the impedance seen by the panel, the operating point can be moved towards peak power point. Since panels are DC devices, DC-DC converters must be utilized to transform the impedance of one circuit (source) to the other circuit (load). Changing the duty ratio of the DC-DC converter results in an impedance change as seen by the panel. At a particular impedance (or duty ratio) the operating point will be at the peak power transfer point. The I-V curve of the panel can vary considerably with variation in atmospheric conditions such as radiance and temperature. Therefore it is not feasible to fix the duty ratio with such dynamically changing operating conditions.

MPPT implementations utilize algorithms that frequently sample panel voltages and currents, then adjust the duty ratio as needed. Microcontrollers are employed to implement the algorithms.

On the hardware side MPPT technology is implemented by use of DC-DC conversion technology with high switching frequencies typically in the range of 15 to 80 KHz.  Such high switching frequency has the advantage of being more efficient.  But it also brings the challenges of EMI, etc.  To achieve the best result and optimum ratio of Efficiency, performance and reliability requires a very careful design.

Technical Details of Final Deliverable

 Inductor Design

        Inductor is a reactive element created to store up the energy in its field which is magnetic. Inductor always resists the change of current flow across it. The current out of the inductor cannot change rapidly while the ideal inductor doesn’t dispute energy. The takes the energy of the circuit when it stores energy and supplies power to the circuit when it is returning previously stored energy. The presence of the winding resistor makes the inductor both energy stored devices and energy degeneracy device. Since the winding resistor is generally very low so in most cases it is overlooked. Below the is formula to calculate the inductor value.

L=Vo(1-D)fs?I

 Where

Vout = output voltages, D = duty cycle, Fs= switching frequency. ?I= ripple current

Our inductor value by using above formula is 80uH and 106.66uH because this is 4th order system that’s why this converter has two inductors and two capacitors by taking Fs 50 kHz, ?I= 0.05 Vo= 12v and duty cycle range from 0.0.1 to 0.9. Our inductor core is iron core (yellow/white)

 Iron (Yellow/White) Inductor Core

The core was wound by 18 gauge wire around 1st inductor has 33 wound which is 80uH and second inductors has 53 wound which approximately has equal to 107uH.

Buck boost converter:

The buck–boost converter is a type of DC-to-DC converter that has an output voltage magnitude that is either greater than or less than the input voltage magnitude. It is equivalent to a flyback converter using a single inductor instead of a transformer.[1] Two different topologies are called buck–boost converter. Both of them can produce a range of output voltages, ranging from much larger (in absolute magnitude) than the input voltage, down to almost zero.

In the inverting topology, the output voltage is of the opposite polarity than the input. This is a switched-mode power supply with a similar circuit topology to the boost converter and the buck converter. The output voltage is adjustable based on the duty cycle of the switching transistor. One possible drawback of this converter is that the switch does not have a terminal at ground; this complicates the driving circuitry. However, this drawback is of no consequence if the power supply is isolated from the load circuit (if, for example, the supply is a battery) because the supply and diode polarity can simply be reversed. When they can be reversed, the switch can be on either the ground side or the supply side.

Final Deliverable of the Project

Hardware System

Core Industry

Energy

Other Industries

Core Technology

Others

Other Technologies

Wearables and Implantables

Sustainable Development Goals

Required Resources

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