Control strategy for load tracking and voltage control of a Grid integrated Solar/Fuel-cell Hybrid Distribution System

The hybrid distributed generation system comprises of one or more AC or DC distributed energy sources, grid-connected inverter, transformer and a filter. The analysis and controller design for a solar cell/fuel cell distributed generation system is described in this paper. The active power from distributed source to grid depends on the angle between inverter voltage and the voltage at the grid and the reactive power depends on these two voltage magnitudes. Using a Proportional Integral controller-based grid-connected inverter, the power flow to the grid from the distributed energy source can be controlled. In the proposed inverter controller, a reference signal is generated by the Proportional Integral controller. The hysteresis controller can generate inverter gate pulses by tracking the reference signal. The load variation at the grid is given as a step input and the waveforms at the output of grid-connected solar/fuel cell hybrid system is simulated. The simulation of the Photovoltaic/Solid Oxide fuel Cell system is done using the MATLAB/Simulink power system toolbox and the operation of the system and the controller is verified. The output voltage remains constant even if the load changes and the total harmonic distortion of the voltage is measured as 0.97%.