Grid Connected PV System (Two PV Array Models) in MATLAB

Grid Connected PV System (Two PV Array Models) in MATLAB

Introduction

We'll delve into a grid-connected photovoltaic (PV) system in MATLAB. Specifically, we'll examine a system comprising two PV arrays connected to a common DC link via boost converters. The goal is to design and analyze this system's behavior under varying irradiation conditions.

System Overview

1. PV Arrays: Each PV array consists of several strings, with 18 series-connected modules per string. The key specifications include maximum power, open circuit voltage, and short circuit current.

2. Boost Converters: Each PV array is equipped with a boost converter designed to maintain the DC link voltage around 1000 volts.

3. MPPT Algorithm: The boost converters employ Maximum Power Point Tracking (MPPT) algorithms to extract maximum power from the PV arrays.

4. Grid Connection: The system is grid-connected, with power from the PV arrays being sent to the grid via an inverter.

Modeling and Control

1. Boost Converter Design: The boost converters are designed based on the power rating of the PV arrays and input/output voltage requirements.

2. MPPT Control: MPPT algorithms regulate the boost converters to maximize power extraction from the PV arrays.

3. Voltage and Current Control: A voltage control loop is implemented to regulate the DC link voltage, while current control loops manage power flow to the grid.

4. Inverter Control: Inverters convert DC power from the PV arrays to AC power suitable for grid connection.

Simulation and Analysis

1. Irradiation Variation: The system's response is analyzed under varying irradiation levels for both PV arrays.

2. Power Extraction: The power extracted from each PV array is monitored, along with grid and inverter currents.

3. System Stability: The system's stability and performance are assessed under different operating conditions, ensuring reliable grid connection and power delivery.

Results and Observations

1. Power Extraction: The PV arrays extract maximum power under varying irradiation levels, optimizing energy generation.

2. Grid Connection: Power is efficiently transferred to the grid via the inverter, maintaining stability and grid synchronization.

3. Controller Performance: The MPPT and voltage/current control loops effectively manage power flow and ensure system reliability.

Conclusion

Grid-connected PV systems play a crucial role in renewable energy integration. Through MATLAB modeling and simulation, we've demonstrated the design and analysis of such systems, highlighting their performance under different operating conditions. By optimizing controller parameters and system configurations, reliable grid connection and efficient power generation can be achieved.