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Abstract
In this report, we have proposed a diode clamped multilevel inverter using renewable energy. Now a days renewable energy is widely playing an important role in the field of generating electricity because it is pollution free, easily form and limitless. Among the renewable energy sources, the photovoltaic systems are mostly used because it is easily installable. Photovoltaic cells converts sunlight into electricity in the form of DC. For this converting purpose we want a suitable converter is needed which convert dc power into ac power. The multilevel inverters (MLI) can be used to convert dc into ac for integration of renewable energy sources into the conventional grids. But the conventional (MLIs) such as diode clamped (MLIs) require extra diodes with the active switches. This report proposed a new type of multilevel inverter which convert dc power into ac power using less number of switches. The proposed inverter can be to integrate the photovoltaic system into grid, which require the best their phase angle, amplitude, frequency, and grid voltage. The simulation on the proposed Seven level (MLI) has done in mat lab software and also results are verified.

Introduction:
Electrical energy generation from renewable energy sources such as sun, biomass, wind, tidal etc, are widely used due to the large consumption of electricity. Currently, people attract toward the (MLIs) multilevel inverters renewable energy systems because conventional (MLIs) such as coal, thermal, hydral, fuel etc are .We used renewable energy source, photovoltaic because it does not give any harm to the environment like it is pollution free, clean etc. The basic component of (PV) photovoltaic system is the solar cell. A solar cell directly converts energy of sunlight directly into electricity in the form of dc.
Components which have used:
? Diodes
? Transistors
? Capacitors
? Solar plate
? Charge Controller
? Battery
? Inverter
Working Of Each Component:
Diode:
Diode is a device which has two terminals anode and cathode as shown in figure 1.1. In fig.1.1 the schematic symbol have shown that where the “+” terminal called the anode which is connected with the p-region and the “-” terminal called the cathode which is connected with the n-region. The main function of diode is to flow current in only one direction that’s why called it unidirectional device while it block current in other direction. The diode operates in three different states.
• Forward bias
• Reverse bias
• Breakdown

Forward Bias:
When positive (+ve) side of battery is connected with p-type material and negative(–ve)side of battery is connected with N-type material across the diode, which has the effect of decreasing the PN junction diode width.
Reverse Bias:
When positive (+ve) side of battery is connected with N-type material and negative (-ve) side of battery is connected with P-type material across the diode, which has the effect of increasing the PN junction diode width.
The diagram will makes you more the working of diode in forward and in reverse bias.

VI- Characteristics Of Diode

Transistor:
Transistor is bipolar device3 which has three terminals collector, emitter and base. There are two types of transistors BJT and FET. The BJT (bipolar junction transistor) transistor called as bipolar device because electrical charge carriers (electron and holes) are involved in making the current flow. The basic work of BJT is to amplify current that’s why it is called the current controlled device.

The BJT has two types NPN and PNP:
We have used PNP transistor in multilevel inverter.

Construction of PNP:
The construction of PNP transistor is shown in the figure below.

The emitter-base junction is connected in forward biased, and the collector-base junction is connected in reverse biased. Due to which the emitter pushes the holes in the base region. These holes produce the emitter current (IE). When these electrons move into the N-type semiconductor material or base, they combined with the electrons. The base of the transistor is thin and very lightly doped. Hence only a few holes combined with the electrons and the remaining are moved towards the collector space charge layer. Hence develops the base current (IB).
The collector-base region is connected in reverse biased. The holes which collect around the depletion region when coming under the impact of negative polarity attracted by the collector. This develops the collector current (Ic). The complete emitter current flows through the collector current IC.

Capacitor:
Capacitor is a device which has two terminals which stores electrical charges.

Construction of Capacitor:
Capacitor has two plates called electrodes. In between two plates there is a die-electric material Such as air, paper, glass etc.

When we connect a battery means DC source with a capacitor the battery charges the capacitor until the capacitor’s voltage is equal to battery voltage. When we disconnect the battery the capacitor discharges.

Solar Plate:
• Photovoltaic cell or solar cell is a light sensor device that converts light energy into electric energy. Solar cells are basically PN junctions with a transparent P layer. Shining light on the transparent P layer causes a movement of electrons between P and N layers, thus producing a small dc voltage. Typical value is 0.5 V per cell in full sunlight.

The junction of dissimilar materials (n (+) and p (-) type silicon) creates a voltage, Energy from sunlight knocks out electrons, creating an electron, connecting both sides to an external circuit causes current to flow, In essence, sunlight on a solar cell creates a small battery with voltages typically 0.5 volt DC.