Researcher : Daeseong Park

This PhD project is aimed to establish dynamic models and model-based design tools for shipboard integrated power systems with power electronics-based onboard grid and multi-layer control systems. The models are applied to stability analysis of the system with variation of design and control parameters.

The resulting stability analysis tool will be used for the secure design and the digital control of the power systems applicable to hybrid electric and pure electric marine vessels. The PhD work will be performed in close collaboration with industrial and academic research partners.

Figure: PhD project overall description

Modeling

Modeling can be divided into linear model for control and stability analysis and nonlinear model for numerical simulation.

Normally, literature study will be carried out and the modeling work will be done by using MATLAB/Simulink and Simscape software. For each power component, several modeling methods will be compared, especially for the power converters. 

The consideration of the fast switching signals should be done due to the converter switches and its influence on the stability. For some components such as diesel engines, the possibility for the application of the machine learning tool will be investigated in order to reduce the complex model. Finally, the completed power system model will be used for HIL (Hardware-in-the-loop) testing.

Keywords: Shipboard power system modeling, Diesel generators, Power converters (switching and average modeling), Load modeling with VSD, Energy storage systems, Filters and passive elements, HIL testing

Control

Control methods should be employed in each component. For most of voltage and current control, PI or PR (Proportional Resonant) controller will be used with its stability analysis with phase margin and cut off frequency on Bode plot.

However, the advanced control method such as sliding mode control, model predictive control, hybrid dynamical control, etc. can be utilized. Lastly, for the optimal design of PEMS which will configure operational scenarios of the equipment, nonlinear integer nonlinear programming (MINLP) will be studied.

Keywords: Power and energy management system, PI & PR control, Model predictive control, MINLP (Mixed integer nonlinear programming)
 

Stability Analysis

Stability analysis will be carried out based on small signal approach. Therefore, all the mathematical derivation of the system should be linearized at the operating point, and the eigenvalues of the system will be obtained so that the system can meet Hurwitz stability criterion.

Many cases should be arranged in order the determine system parameters, so the parametric analysis for the stability will be performed.

Keywords: Small-signal stability analysis

Publications

3. Ghimire, Pramod; Park, Daeseong; Zadeh, Mehdi Karbalaye; Thorstensen, Jarle; Pedersen, Eilif. (2019) Shipboard Electric Power Conversion: System Architecture, Applications, Control, and Challenges. IEEE Electrification Magazine. vol. 7 (4).

2. Hatlehol, Marius Ulla; Park, Daeseong; Zadeh, Mehdi Karbalaye. (2019) A Modified Sliding Mode Controller for Active Stabilization of DC Microgrids with Constant Power Load. Proceeding 45th Annual Conference of the IEEE Industrial Electronics Society - IECON 2019.

1. Park, Daeseong; Zadeh, Mehdi Karbalaye. (2019) Dynamic Modeling and Stability Analysis of Onboard DC Power System for Hybrid Electric Ships. 2019 IEEE Transportation Electrification Conference and Expo (ITEC).

Project Partners

Norwegian University of Science and Technology (NTNU)

Hyundai Heavy Industries (HHI)

Project Duration

September 2018 - February 2022