Flatness based control of a variable speed micro hydrokinetic generation system

In this paper, the concept of differential flatness is applied to a controller with the aim of producing constant voltage and frequency from a hydrokinetic with permanent synchronous generator submitted to variable water flow. The idea of this concept being to generate an imaginary trajectory that will take the system from an initial condition to a desired output generating power. The results show that, the generated output is dynamically adjusted during the voltage regulation process. The advantage of the proposed differential flatness based controller over the traditional proportional integral (PI) control is that decoupling is not necessary, as demonstrated by the modelling and simulation studies under different operating conditions, such as changes in water flow rate.