Mitigation harmonic with LCL passive filter in off-grid PV system

Abstract

The increased use of power electronic based devices and the nonlinear characteristics of circuit elements used in these devices have led to the formation of harmonic components in power systems. The stable and safe working of power systems depends on the foundation of quantities such as voltage and current, which are sinusoidal and at 50 Hz frequency. However, these foundation quantities lose their sinusoidal characteristics because of many reasons and unwanted harmonic components occur in the off-grid power system. It is highly preferred to use passive LCL filter to reduce the harmonic components that occur in the solar system. The proposed power system is a combination of solar panels, a DC/DC boost converters, solar inverters, six-pulse rectifiers, passive LCL filters and RL inductive loads. A six-pulse uncontrolled rectifier produces 5th, 7th, 11th, 13th, 17th, 19th, etc. Harmonic components. A passive LCL filter is used to reduce the input current of the total harmonic distortion (THDI) of an uncontrolled rectifier. According to these results, the designed passive LCL filters have a simple structure and control is not too complicated provides significant advantages and are not complicated to control, which provides significant advantages. Modelling of off-grid PV power system and simulation was performed with Matlab/Simulink. Simulation results showed that the THDI value reduced from 91.53 % to 2.927%. As a result, LCL filter improves both the system efficiency and reliability of standalone PV power systems.