PI-IMC control for frequency deviation control in Islanded micro gric

This work faces the problem of frequency deviation in microgrid systems. The considered microgrid includes renewable energy sources such as wind and solar photovoltaic. As long as these sources provide an irregular power supply or there is a sudden change in the system load, the power system frequency deviates. In order to compensate such deviations, alternative, conventional energy sources should be commanded in order to provide the corresponding power deficit. In this paper a very simple and of common industrial practice control approach such as the Internal Model Control based on first order plus time delay models is proposed to tune a PI controller. As the commanded energy sources are based on fuel consumption, the control usage has to be maintained at low levels. It is shown that the PI control approach is able to provide accurate frequency deviation control with very low movements for the control signal. Time domain simulations show the effectiveness of the approach as compared with other more sophisticated controllers (Fractional order PID) already proposed in the literature.