Review of Ship Microgrids: System Architectures, Storage Technologies and Power Quality Aspects

Abstract

Ship microgrids have recently received increased attention, mainly due to the extensive use of power electronically interfaced loads and sources. Characteristics of these microgrids are similar to islanded terrestrial microgrids, except the presence of highly dynamic large loads, such as propulsion loads. The presence of such loads and sources with power-electronic converter interfaces lead to severe power quality issues in ship microgrids. Generally, these issues can be classified as voltage variations, frequency variations and waveform distortions which are commonly referred to as harmonic distortions. Amongst the solutions identified, energy storage is considered to be the most promising technology for mitigating voltage and/or frequency deviations. Passive filtering is the commonly used technology for reducing harmonic distortions, which requires bulky capacitors and inductors. Active filtering is emerging as an alternative, which could be realised even within the same interfacing converter of the energy storage system. The aim of this paper is to investigate recent developments in these areas and provide readers with a critical review on power quality issues, energy storage technologies and strategies that could be used to improve the power quality in ship microgrids. Moreover, a brief introduction to ship power system architectures is also presented in the paper.

Challenges of Microgrids in Remote Communities: A STEEP Model Application

“…Microgrids have been defined in various ways, all of which present them as a smaller version of the electric power grid [46][47][48][49][50][51][52][53]. They are a localized arrangement of electrical sources and loads that operate in connection to the existing grid system, i.e., the on-grid mode, and can also operate as a stand-alone energy system when disconnected from the grid, i.e., off-grid mode.…”

Study of Shipboard Power Distribution System: Review on an Aplication of AC Zonal Distribution

“…Segregated power distribution is a system that separates between the main propulsion system and the auxiliary system [6]. This system has advantages in terms of installation, maintenance, and operation.…”

Effect of Load Changes on Hybrid Shipboard Power Systems and Energy Storage as a Potential Solution: A Review

“…However, this is likely to be influenced by the size and amount of ca rgo operations required for the ship. The corresponding figures for Reefer ships, Ro-Ro ships, tankers and Bulk cargo ships are on average, 2 MW, 0.7 MW, 5 to 6 MW and 0.3 to 1 MW [21].…”

“…The bar chart plots the Percentage of running hours against the Main Engine load. The exemplary load profiles of a harbor tug with two forward thrusters supplied by a 2040 KW diesel engine that tows container ships is shown in Figure 4 while that of a passenger motor ferry with a 50 KW service load and driven by 2 × 470 KW gas engines that does a 40-min to and fro journey [21] regularly is as below in Figure 5. It is observed that the load variation has a more evenly balanced distribution approaching a typical normal distribution in the case of the container ships while smaller vessels such as tugs and ferries have a more skewed profile.…”

“…For example, the port of Los Angeles provides shore-side electrical power to the ships at its berth in order to reduce the emissions that might arise if the ships were to run on their diesel power. The average energy consumed by the different types of vessels berthed at the port [21] is summarized in Table 3 below. It has also been found that a container ship can use as much as 4 MW of shore power at the berth.…”