Analysis and Design of Grid-Tied Inverter With LCL Filter

Abstract

The LCL filter represents the state-of-the-art passive interface type for grid tied power converters as a cost and space reducing alternative to single coil solutions for switching harmonic attenuation. However, a simple PI controller can cause instabilities when applied to control the current of this filter. Thus a general analytically closed approach is presented to determine the safe operating areas for both grid current control mode (GCM) and inverter current control mode (ICM), both with and without additional active damping feedback of the capacitor current. The proposed approach consequently applies the Nyquist criterion in the continuous frequency domain, facilitating the determination of very simple expressions of parameter stability limits. These design guidelines, which partially also confirm previous findings, are for the first time summarized all together as the results of proposed approach to aid corresponding controller design. INDEX TERMS PWM inverter, LCL filter, active damping, stability analysis.

Design and Control of A Single-Phase Grid-Connected Inverter

“…The advantages, disadvantages, and main attributes of grid-connected inverter structures are presented in [6]. An analytical approach is also examined in this of type inverter structure to provide the stability of the system [7]. Modeling, analysis, and design studies of grid-connected inverter structures are also investigated in PV integrated applications [8][9][10].…”

Metodologia de projeto integrada para filtro LCL (modo comum e diferencial) e controlador de corrente aplicada à inversores fotovoltaicos monofásicos sem transformador conectados à rede elétrica.

“…Inversores sem transformador do tipo fonte de tensão, com filtro de saída do tipo LCL (indutor-capacitor-indutor), vêm sendo amplamente empregados para a obtenção de baixas perdas de conversão, redução de volume, peso e custo (RUAN et al, 2018), (BIERHOFF;SOLIMAN;ESPINOZA C, 2020), (KHAN et al, 2020), (XIAO;WANG, 2021), (XIAO, 2021), (BOLSI et al, 2021).…”