abstract

ABSTRACT

• Photovoltaic (PV) is one of the clean and free-pollution renewable energy, but it is an unreliable source because of the intermittent feature of weather.

• Well integration of the MPPT technique with PV array model will ensure the system operates at its maximum power point at different weather conditions and solar irradiation.

• This paper use the MATLAB Simulink to simulate the model.

INTRODUCTION

• Recently, the needs of renewable energy resources increase due to the fuel energy crisis and the global warming issue. Solar energy is one of the most important renewable energy

• Solar energy using photovoltaic (PV) has several advantages, e.g., no noise and free pollution.

• Two operational problems, the efficiency is very low especially under low irradiation conditions and in the intermittent weather condition the electric power changes continuously.

• What is MPPT and why it is needed? (Maximum power point tracking)It is needed a controller (MPPT) to achieve the highest efficiency and provide a stable power under the intermittent weather condition

• Why IC technique ?It shows good performance under the intermittent of solar irradiance

The simulation result will show how good is the performance of this IC technique.

PV Model• A solar cell basically is a p-n semiconductor

junction. When exposed to light, a dc current is generated.

PV Characteristic

IC MPPT Technique• The incremental conductance method is

developed under the fact of slope of the PV array power curve is zero at the MPP

IC MPPT Algorithm

Block Diagram of the Proposed PV System

PV ARRAY

BOOSTCONVERTER

PVINVERTER

3-PHASEGRID

IC MPPT CONTROL

I

V

PV INVERTERCONTROL

AC

DCDC

SIMULATION SYSTEM

Under mask the system

Simulation under constant solar irradiance• The maximum standard operating for constant solar irradiance is assumed

to be 1000 W/m2 in the study.

(A) The measured output of PV Module (B) The respond of IC MPPT tracking algorithm

Under 1000 W/m2 of solar irradiance, The duty cycle for boost converter is a constant value 0.45 and the booster convert around 92kW of power with constant ouput voltage 500 V to the PV inverter.

Output from boost converter

The PV module provides 100kW and the boost converter convert 92kW of energy

Comparison of the measured output of PV module with output of boost converter

Simulation under decreasing solar irradiance

(A) Decreasing of solar irradiance (B) Duty cycle of boost converter

The figure shows the decreasing solar irradiance (1000 W/m2- 800 W/m2 -250 W/m2).

(A) The measured output of PV Module (B) The respond of IC MPPT tracking algorithm

The figure shows the power, voltage, current of boost converter. Under (1000 W/m2- 800 W/m2 -250 W/m2) of solar irradiance, the booster convert around 92kW - 80 kW - 25 kW of power. The

booster maintains the output of voltage to be 500 V to the PV inverter.

Output from boost converter

The PV module provides 100kW (1000 W/m2) 80kW (800W/m2) 25kW (250 W/m2) and the boost converter convert 92kW, 74kW, 20 kW

Comparison of the measured output of PV module with output of boost converter

Simulation under different solar irradiance

Figure B shows the duty cycle of boost converter responding to different solar irradiance. In fact, an extreme variation of solar irradiance occur rarely.

The figure A shows the variations of solar irradiance (600 W/m2- 800 W/m2 - 400 W/m2 -600 W/m2)

(A) The measured output of PV Module (B) The respond of IC MPPT tracking algorithm

The figure shows the measurement output from boost converter. The figure shows the power, voltage, current of boost converter. Under (600 W/m2- 800 W/m2 - 400 W/m2 -600 W/m2) of solar irradiance, the booster maintains output voltage to be 500 V constantly.

Output from boost converter