Energy-based compensation strategy for active filters

We present an energy-based approach for the control of shunt active power filters based on voltage source inverters. These are commonly used to compensate for current harmonics, unbalance and reactive power produced by nonlinear, time-varying and fluctuating loads. The main control issues on these applications arise from the possible presence of unknown dynamics and parameter uncertainties in the load and in the power line. This, however, is often the case when active filters are used not only to compensate a specific distorting load, but also to handle a group of loads. We explore the effectiveness of a family of controllers based on the generalized averaging techniques and on notions of incremental energy and dissipativity. We obtain a compensation strategy that allows stable active filter operation regardless of line and load parameter variations. Moreover, an adaptive procedure, which allows precise reference tracking, is also presented. Simulation results indicate the effectiveness and validity of the proposed method.