Development of a Multiphysics Real-Time Simulator for Model-Based Design of a DC Shipboard Microgrid

Abstract

Recent and strict regulations in the maritime sector regarding exhaust gas emissions has led to an evolution of shipboard systems with a progressive increase of complexity, from the early utilization of electric propulsion to the realization of an integrated shipboard power system organized as a microgrid. Therefore, novel approaches, such as the model-based design, start to be experimented by industries to obtain multiphysics models able to study the impact of different designing solutions. In this context, this paper illustrates in detail the development of a multiphysics simulation framework, able to mimic the behaviour of a DC electric ship equipped with electric propulsion, rotating generators and battery energy storage systems. The simulation platform has been realized within the retrofitting project of a Ro-Ro Pax vessel, to size components and to validate control strategies before the system commissioning. It has been implemented on the Opal-RT simulator, as the core component of the future research infrastructure of the University of Genoa, which will include power converters, storage systems, and a ship bridge simulator. The proposed model includes the propulsion plant, characterized by propellers and ship dynamics, and the entire shipboard power system. Each component has been detailed together with its own regulators, such as the automatic voltage regulator of synchronous generators, the torque control of permanent magnet synchronous motors and the current control loop of power converters. The paper illustrates also details concerning the practical deployment of the proposed models within the real-time simulator, in order to share the computational effort among the available processor cores.

Optimization of a Fuzzy Automatic Voltage Controller Using Real-Time Recurrent Learning

“…The job of an AVR consists of maintaining the magnitude in the energy of a synchronous generator at a certain level; hence, the stability in an AVR may affect the security in an energy system [5]. Furthermore, an AVR can be found in a Direct Current (DC) Microgrid system to regulate the Alternating Current (AC) power produced by the generators before rectification and then supplied to DC grid [6].…”

Optimisation of a Diesel-Electric Ship Propulsion and Power Generation System Using a Genetic Algorithm

“…A significant improvement to the efficiency of diesel-electric propulsion systems is due to the recent introduction of variable revolution speed generators [23], allowing the diesel engines to work in their optimal efficiency conditions. This type of engine control logic is coupled with direct current (DC) distribution in order not to constrain the alternators to produced energy at a fixed distribution frequency, as opposed to alternate current (AC) distribution [24][25][26].…”

Electrical and Energy Systems Integration for Maritime Environment-Friendly Transportation

“…It is clear from these examples that there is no single solution to the issue, but different approaches can be successfully exploited to improve upon the actual environmental performance. The design of ship power and propulsion systems is also a hot topic [8][9][10], due to the similarities between shipboard and land based microgrids [11]. As an example, in [8] the authors apply the model-based approach to the design of a DC shipboard power system, by means of a multiphysics real-time simulator.…”

“…The design of ship power and propulsion systems is also a hot topic [8][9][10], due to the similarities between shipboard and land based microgrids [11]. As an example, in [8] the authors apply the model-based approach to the design of a DC shipboard power system, by means of a multiphysics real-time simulator. Similarly, a battery based shipboard power system design is presented in [9], discussing different operation scenarios and using a MATLAB based model to validate the results.…”