Open-loop maximum power point tracking strategy for Marine Current Turbines based on resource prediction

Abstract

This paper presents the theory for a model-based Maximum Power Point Tracking (MPPTs) strategy for Marine Current Turbines (MCTs) that computes the optimal operating point using resource prediction and a look-up table. The high predictability of the Marine Currents (MCs) is exploited in order to produce a simple algorithm that calculates offline the optimal operating point for an evolving date and time. This eliminates the use of sensors to measure the current or the use of a perturbation to scan the curve. Two MPPT methods based on this strategy are discussed in detail: 1) fixed rotating speed with variable pitch angle and 2) fixed pitch angle with variable rotating speed. As a result, the two proposed MPPT methods improve the efficiency of the MCT creating a sensor-less, open loop strategy with precision and simplicity. The information needed to predict the MC is obtained through site characterization, a process required for any investment in green energy. The effectiveness of the proposed strategy is demonstrated through simulations.