Electric Propulsion Naval Ships with Energy Storage Modules through AFE Converters

Abstract

This paper proposes a novel electric propulsion system for naval ships, which consists of Active Front End (AFE) converters directly connected to battery Energy Storage Modules (ESMs). Employing the proposed AFE converters with ESMs in the power systems of naval ships can enhance the reliability and quality of the electric power. Furthermore, the fuel-efficiency of the generator can be improved by a higher loading factor of the generator and its prime movers. The proposed AFE configuration does not require an additional dedicated DC/AC converter for the ESMs. Instead of that, the AFE converter itself can control the DC link voltage and the discharging and/or charging of the ESMs. A control scheme to achieve these control objectives is also presented in this paper. The overall power system, including the generators and electrical loads of a naval ship, is implemented by a small scaled Power Hardware-In-the-Loop (PHIL) simulator. Through this experimental setup, the proposed system configuration and the power control strategies are verified. It is shown that the fuel-efficiency and transient dynamics can be improved in the normal and contingency operation modes.

Small scaled Power Hardware-In-The Loop and control method of ship integrated power system with active front end converter and battery energy storage system using low cost multicore DSP

“…In the case of without active power source, several frequency stabilization methods which sacrifices the kinetic energy of the ship mass or the rotating energy of the propulsion motor inertia was suggested [2][3], but these methods degrade propulsion dynamics and reduce propulsion power of the ship. The energy storage system such as Battery Energy Storage System (BESS) provides not only grid frequency stabilization possibility but also broaden an operational area of generator set [4]. Simultaneously, BESS associated with AFE can act as an Uninterruptible Power Source(UPS) in the case of deadship.…”

“…The AFE converter which connects between PCC and the propulsion inverter was studied in [2,4]. In [2] the separate model of generator side and AFE converter side were used and the interactions between generator and AFE converter cannot be investigated because of the independent modeling of two sides.…”

“…Meanwhile, the modeling of the naval ship IPS for an off-line simulation [2,[5][6], a Hardware-Inthe-Loop Simulation (HILS) [7] or a Power HILS (PHILS) has been researched [3][4][8][9]. The purpose of these researches was for verification of the stability and performance of the ship IPS, preceding a full scale experiment which not only consumes lots of time, cost and space but also causes a safety issue.…”

“…In [2] the separate model of generator side and AFE converter side were used and the interactions between generator and AFE converter cannot be investigated because of the independent modeling of two sides. In [4] BESS connected to the DC link of AFE converter was introduced, and the generator side and AFE converter side was modeled in whole. The ship hydrodynamics and down scaling of motor were explained literally.…”

Nonlinear optimal control for ship propulsion with the use of an induction motor and a drivetrain

“…Besides, by considering variable pitch angle at the propeller's blades an additional control input can be generated, allowing for a more dexterous manipulation of the ship's motion [7]- [8]. The results of this article contribute to developing a more efficient control system for an electric ship's propulsion and to managing optimally the associated power electronics [9]- [11]. Actually, in the present article, a nonlinear optimal control approach is developed for the propulsion system of electric ships, comprising a three-phase induction motor, a drivetrain and a propeller.…”