A Simplified Power Regulation Strategy for Grid-tied PMSG-based Marine Current Turbine System in High-speed Marine Current Conditions

Abstract

Marine current turbine systems (MCTSs) play a crucial role in harnessing renewable energy from ocean currents. These systems are designed with specific rated values of marine current speed, dictating their optimal operational parameters. However, the dynamic nature of marine currents can lead to fluctuations, occasionally exceeding the rated values for which these systems are designed. This poses significant challenges to the efficient and safe operation of MCTSs, necessitating the development of effective power regulation strategies. In response to these challenges, this paper presents a simplified power regulation strategy to address the complexities of high-speed marine current conditions. The strategy focuses on constraining the reference torque command, a pivotal parameter governing power generation within MCTS. By precisely managing the reference torque command, the strategy aims to ensure that power output remains within designated limits, thereby safeguarding the MCTS despite high-speed marine current conditions. The proposed strategy leverages a computational approach to determine the generator's reference torque command, utilizing key parameters such as the rated power of the MCT and the mechanical angular rotor speed. It facilitates seamless transition between unconstrained reference torque command (URTC) and constrained reference torque command (CRTC) modes, enabling precise power regulation. This flexibility empowers the MCTS to respond promptly to changes in marine current conditions, facilitating precise and responsive power regulation. To validate the effectiveness of the proposed strategy, the paper conducts a comprehensive analysis of MCTS performance across both URTC and CRTC modes utilizing Typhoon HIL604 real-time simulator. Through detailed examinations of MCT speed responses, generator torque, output power, and grid-side parameters, the study provides valuable insights into the dynamics of MCTS operation. This comprehensive understanding enhances the stability and adaptability of MCTSs across diverse operating conditions, thereby advancing their potential as a sustainable energy solution.