Second and third-order passive filters (LC and LCL) are interesting filters to use for grid-connected PWM inverters. Because of the stability problems of these filters around resonance frequency, series and damping resistor can be add to an LCL filter. However, the resistor value has impact on the filter respond, voltage and current harmonic distortion and filter power loss. In this paper, the ...

This paper analyses the characteristics of LCL filter in active power filter (APF) and provides an accurate for mula to determine the resonant frequency of system. Based on a single-phase equivalent circuit model, a systematic approach to design APF with LCL filter is proposed. Total inductance is determined by the capability of APF. Moreover, damping ratio, resonant frequency and attenuation d...

Three-level gird-connected converter is used more and more widely in renewable energy generation system. At the same time LCL filter is also widely utilized in order to achieve lower current harmonic. However, current research about LCL filter is mostly aimed at two-level inverter. The study involving multilevel inverter is much less. When using space vector pulse width modulation, Current tran...

Voltage-oriented PI control of three-phase gridconnected pulsewidth-modulation rectifiers with LCL filters is addressed. LCL filters require resonance damping. Active resonance damping is state of the art to face the problem, but it is still under investigation because of the manifold solutions. It is often realized using many sensors and/or complex control algorithms. In contrast, pure PI cont...

Although LCL filters are used widely in the grid connected inverters to reduce high-orderharmonics, such a system increases system order and therefore sustainable design of closed-loopcontroller system will be complicated. Recently, the single-loop control strategy has beensuggested for L or LC filter based grid-connected inverters. However, the use of single-loopcontrol directly in LCL filter-...

This paper establishes an LCL-filters design and control for three-phase grid inverter. The crucial object is to conquer optimum damping with a required system control bandwidth for the LCL-filter. This control technique is achieved by using Bacteria Foraging Optimization. Mathematical analysis has been introduced to investigate the steady-state and dynamic performances of the overall system. T...