Feeding Unbalanced Loads by Controlling four leg Inverters using Resonant Controllers leg

In recent years the number of distributed generators which are connected to a network, or directly feed local loads, is growing. Most of these generators need power inverters for their power transmission. On the other hand, in a power system most of the times, the loads are dynamic and change over time or even in some cases, they might become unbalanced. In this paper, we have chosen a switching method presented for four-leg multilevel inverters. The method is based on the switching of two-level inverters which has a simple structure and generality for applying to any topology with any number of levels. Then, a technique for controlling inverters connected to unbalanced loads is presented based on resonant controllers. The presented method benefits from a very simple structure and can be implemented in a synchronous reference frame. At the end, a number of simulations are performed in MATLAB in order to validate the effectiveness of the proposed method and the results are presented.

Keywords:

Four-leg Inverters , Multilevel Inverters , Resonant Controllers , Unbalanced Loads