Gain and phase margins based stability region analysis of time-delayed shipboard microgrid with sea wave energy

Abstract

One of the used areas of wave energy conversion systems is shipboards. In shipboard microgrid with wave energy conversion systems, load frequency control is very important because of the over-variable nature of the energy generated by wave energy conversion system. In this study, new controller design for load frequency control of the shipboard microgrid with wave energy conversion systems is proposed. With the proposed controller design, the system is operated in suitable stable parameter space in order to guarantee the desired gain and phase margins and the system is more stable against the uncertainties of parameters that will occur. A virtual phase and gain margin tester is added to the shipboard microgrid with wave energy conversion systems in order to take into account the gain and phase margin in the stability region calculations. First, the characteristic equation of this system is obtained. After the appropriate conversion operations on the obtained characteristic equation, the stable parameter space of the controller is calculated by taking into account time delay, gain and phase margin. Eigenvalue and time-domain analysis studies are performed on the system to show the accuracy of the stability region results. © The Institution of Engineering and Technology 2020