A novel current controller design for grid-integrated PV inverter system

Ayaz Ahmad,L Rajaji,A Iqbal

doi:10.1007/s42452-021-04290-4

Ayaz Ahmad, L Rajaji + Show 1 more

Open Access

https://doi.org/10.1007/s42452-021-04290-4

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Abstract

Distributed generators are playing a vital role in supporting the grid in ever-increasing energy demands. Grid code regulation must be followed when integrating the photovoltaic inverter system to the grid. The paper investigates and analyzes a controller model for grid-connected PV inverters to inject sinusoidal current to the grid with minimum distortion. To achieve better tracking and disturbance rejection, a DSP-based current controller is designed with LCL filter. The controller gets the current feedback from the grid, compares it with reference current, and calculates duty cycle to generate PWM pulses to trigger H-bridge converters. The grid voltage is loaded to the initial value in proposed PR controller to ensure the initial inverter voltage to match the grid voltage. The paper presents a novel current controller algorithm for grid-connected inverter system, and simulation is done. A detailed analysis has been carried out to validate the proposed design algorithm. Experimental implementation of the current controller in the DC/AC converter circuits with an LCL filter is done for 5.4 kW to validate and match the simulation model.

Highlights

Better technology, reduced cost, and efficient system are encouraging greening the grid
Proportional resonant (PR) controller is an algorithm used in the current controller which is used to integrate the PV inverter into the grid
This paper proposes a novel design and modeling of the current controller for single-phase grid-connected inverter system

Summary

Introduction

Better technology, reduced cost, and efficient system are encouraging greening the grid. This solar inverter is connected to the power utility grid system through LCL filters. A low-cost gridconnected residential scheme is suggested in [6] based on dynamic voltage or current error signals activating a PI controller Another controller used is low-pass filter in the feedback path along with harmonic compensator to improve the grid current quality [7]. Various control algorithms are presented for active and reactive power control when PV inverters are connected to the grid as given by [13,14,15,16]. PR controller is used to compute PWM duty cycle from the error current

Modeling and simulation of current controller

H Bridge

Simulation results

Experimental implementation and results

Conclusion

Compliance with ethical standards