Development of a FPGA Based Real-Time Power Analysis and Control for Distributed Generation Interface

Energy coming from renewable sources has become very important nowadays, mainly because of their negligible contribution to greenhouse gas generation. A problem that then arises is how to integrate these new sources into a traditional power grid, in such a manner as to maximize the efficiency and reliability of this new distributed generation (DG) system. The hardware to do that is generally a voltage source inverter (VSI) that supplies a common load, as in single-phase residential and commercial applications. The optimizing process requires, of course, the usual power analysis. This paper presents the development and the experimental evaluation of a power control system for a single-phase grid-connected VSI including the power analysis using as processor for the control implementation a field-programmable gate array (FPGA) circuit. New hardware structures of adaptive linear neural networks (ADALINE) allow the implementation of power control algorithms and have also permitted the real-time analysis of the high-order harmonics without increasing the implementation area of the FPGA circuit. These features are ideal for novel DG power electronics interfaces that could be used not only for active power dispatch but also for harmonics and reactive power compensation. Simulation and experimental results of the proposed fixed and variable frequency schemes are included to confirm their validity.