Modeling and Analysis of 3-Phase VSI using SPWM Technique for Grid Connected Solar PV System

ABSTRACT:

Solar energy is one of the most promising Renewable Energy Sources (RES) that can be used to produce electric energy through Photovoltaic (PV) process. The Solar Photovoltaic (SPV) systems which directly supply power to the grid are becoming more popular. A power electronic converter which converts DC power from the PV array to AC power at required voltage and frequency levels is known as Inverter. Generally different Pulse Width Modulation (PWM) techniques have been implemented for grid connected 3-phase Voltage Source Inverter (VSI) system. This paper describes few types of PWM techniques and mathematical model of LC filter circuit is given using state space analysis. Sine-PWM technique is proposed for 3-phase VSI and implemented using the state space model of the LC filter circuit. The simulation is performed in MATLAB/Simulink platform. Simulation results are presented for the inverter and load side to demonstrate the satisfactory performance of the sine-PWM technique.

KEYWORDS:

1.      Pulse width modulation

2.      Solar photovoltaic

3.      Voltage source inverter

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1. General Block Diagram of Grid Connected SPV system

EXPECTED SIMULATION RESULTS:

Fig. 2. Carrier wave (V_tri) and Modulating wave (V_sin)

 Fig. 3. Inverter Output line to line Voltages (V_iAB,V_iBC,V_iCA)

Fig. 4. Inverter Output Currents (i_iA,i_iB,i_iC)

Fig. 5. Load line to line voltages (V_LAB, V_LBC, V_LCA)

Fig. 6. Load Phase Currents (i_LA,i_LB,i_LC)

Fig. 7. Inverter output line voltage, Inverter output current, Load line

voltage, Load phase currents

CONCLUSION:

Increasing demand on energy efficiency and power quality issues, grid connected solar PV systems is taking a good place. In this paper SPWM and SVPWM techniques have been discussed for 3-phase grid connected VSI. The LC filter circuit is used in the proposed system. This filter circuit is mathematically modeled by using state space analysis and complete state space equation is obtained. The SPWM technique is implemented and simulated on 3 phases VSI using state space model of the LC filter circuit for grid connected solar PV system. Various simulation results are analyzed and presented on the inverter and load side of the proposed system in order to demonstrate the satisfactory performance of sine-PWM technique for grid connected solar PV system.

 REFERENCES:

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