A suitable power sharing control of parallel-connected inverters in microgrids

With further development of renewable resources in power systems, application of inverters as interface of these resources has been increased. Parallel connection of inverters is attractive in practice because of some merits such as improving reliability, system redundancy and extending output power. In order to have desirable operation of paralleled inverters, employing an efficient control approach is essential. Conventional control approaches adjust amplitude and frequency of the output voltage to achieve balance power sharing. However, these methods have several drawbacks such as complicated control algorithm as well as frequency and voltage deviations. In this paper, a backstepping control (BSC) method is proposed for parallel-connected inverters in microgrid applications. The proposed BSC scheme is able to achieve the output voltage with a low total harmonic distortion and accurate load sharing among paralleled inverters. The performance of the proposed method is evaluated using some simulations in MATLAB/Simulink and compared with a similar conventional method.