The stability and quality of the electric power are the key factors for a good electricity supply service. On one hand, the stability of the grid is affected by the higher integration of decentralized energy sources based on renewables. On the other hand, the quality of the supply voltage is affected by the increasing usage of electronic devices. Most of the power inverters, used to integrate electricity from decentralized energy sources such as photovoltaic plants or wind turbines farms, are designed as single-task machines. Their main objective is to inject into the grid all the power locally available independently of the grid’s real demand. This behavior could lead to a complete disruption of the grid described as the famous European 50.2 Hz problem. This project proposes a new smart inverter that represents a very good solution to this 50.2 Hz problem. The proposed inverter system controls, very accurately, the active and reactive power flow exchanged between grid and power units fed by renewable energy source. The power set points values do not depend only on the maximum locally producible power but can determined based on the grid frequency (or voltage) or be set by the grid operator. In addition to that, the smart inverter uses the full potential of power electronics as it embeds the ability to mitigate the harmonics that could appear on the grid. The developed solution transforms every decentralized energy production unit into a very flexible and autonomous power unit.