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The increase in greenhouse gas emissions from the transportation sector together with the continued depletion of fossil fuels in general has encouraged an increase in the use of energy storage systems and renewable energy sources at seaports and also on short route yachts and ferries. At present, most seaports, particularly smaller ones, are not provided with cold-ironing facilities - shore-based power facilities, which provide electric power to ships from the national grid. Because of the lack of cold-ironing facilities at most ports, auxiliary diesel engines and diesel generators on ships must be kept operating and online while at berth to supply auxiliary loads of ship. To address these requirements, one possible solution would be to provide cold-ironing facilities at all ports. However, in many circumstances, this is not cost-efficient as a port might be far from the national grid. To overcome these limitations, a seaport microgrid can be formed through the integration of multiple shipboard microgrids (SMGs) with decentralized control together with a charging infrastructure that is located on-shore. This integration of multiple SMGs and port-based charging stations is termed a ship-based seaport microgrid. Typically, power is shared among different microgrids using data communication techniques, which adds to the cost and the complexity of the overall system. This article proposes a communication-less approach based on multimode, decentralized droop control that enables power sharing among several SMGs in both charging and discharging modes based on the state of charge of battery banks - electric power is either supplied or consumed. The proposed approach would be potentially useful for future autonomous ships and also for islands where port electrification is either not technically feasible or an economically viable solution. A simulation and hardware-in-the-loop results are provided to verify the control robustness of the proposed control strategy.

Due to the rapid adoption of power electronics technology in shipboard microgrids (SMGs) in recent years, harmonic contamination has become now a crucial topic for these power systems. In order to sustain the safety of the electrical power systems, standards for power quality have imposed strict limits on the harmonic distortion allowed. In these standards, the application of the fast Fourier transform (FFT) with a window size of 10/12 cycles is often recommended for the harmonic evaluation. This method is not practical for SMGs due to large variations in load and frequency in a short duration. To address this issue, this article proposes a signal periodicity-independent algorithm to estimate the current harmonic distortion of SMGs by solving an eigenvalue problem with a short transient response. The proposed algorithm, which is based on a resolution-enhanced sliding matrix pencil method (SMPM), is distinguished by its frequency independency feature, and as a result of this, feature system frequency variations and the existence of interharmonics do not affect its accuracy. The evaluation of the proposed method is carried out under the MATLAB software and is experimentally verified via analyzing the electrical power system current of a container ship.

Addressing power quality issues in shipboard microgrids (SMs), which are mainly attributable to the increased installation of power converters, has received much attention recently. To this end, static VAR compensators, such as thyristor-switched capacitors and fixed capacitors-thyristor controlled reactors (FCs-TCRs), can be effective solutions. Controlling these compensators, however, is not a trivial task as it involves sophisticated operations, especially estimating the firing angle, which should be carried out based on some nonlinear equations. This article aims to propose the application of some simple yet numerically efficient algorithms based on bisection, Newton-Raphson, false position, and secant methods for estimating the firing angle of the FC-TCR. The effectiveness and robustness of these algorithms are demonstrated via modeling of the FC-TCR with the electrical power system of a practical hybrid ferry under MATLAB/Simulink environment, where the results proved that the enhanced power quality issues respect the IEC standards 61000-4-7/30. Furthermore, an experimental setup consists of a digital signal processor and a programmable source is used to demonstrate that these techniques can be effectively applied in real-time applications.

In recent years, the significant revolution of shipboard micro-grids (SMs) towards all-electric ships offered several advantages such as high efficiency, better maneuverability, and controllability. However, the application of power electronics onboard SMs, particularly for DC and hybrid ships leads to serious power quality issues. The application of passive power filters (PPFs) has been largely used to solve some of the power quality issues, such as harmonics contamination, power factor compensation, and voltage drop enhancement. However, analyzing some crucial factors such as the harmonic attenuation factor (HAF) and filters sensitivity factor (FSF) of these filters have not been attracted much attention. In this paper, a more in-depth mathematical analysis of the HAF and FSF of these filters is conducted with details. Moreover, some developed solutions to improve these factors are suggested. Based on intensive simulation studies of a practical hybrid ferry, which are carried out under MATLAB/Simulink environment, it has been demonstrated that the conducted analysis and proposed solutions can enhance the filtering performance of the PPFs.

This paper proposes a cost-effective compensator to suppress harmonics and compensate the power factor of all-electric shipboard power systems (SPSs). This compensator, which is based on a fixed capacitor-thyristor controlled reactor (FC-TCR), behaves as a low-pass filter and therefore can reject both low and high-order harmonics. Moreover, the FC-TCR compensator is featured by the low switching losses; hence, it can effectively be implemented for low and medium voltage applications. The design of the filter is detailed via equivalent lossy circuits, which exhibit the mechanism of the harmonic mitigation. Furthermore, theoretical analyses and mathematical developments are suggested to enhance the filtering performance. Besides, details of the Fixed-Point iteration technique which is applied to extract the firing angle of the TCR are conducted. A practical SPS is selected to ensure and demonstrate the performance of proposed methodology via thorough simulations under MATLAB/Simulink environment. The obtained results verify the theoretical analyses and confirm the effectiveness of proposed solution.

Recently, the evolutionary development in power electronics (PE) technologies onboard shipboard micro-grids (SMs) has been receiving significant attention. Indeed, this evolution added enormous advantages such as enhanced maneuverability and controllability. However, the installation of PE converters onboard SMs results in serious power quality issues. The application of the fixed capacitors-thyristor controlled reactors (FCs-TCRs) is largely used to improve some of the power quality issues. However, the non-linearity of the firing angle equation increases the complexity of controlling this sophisticated technology. In this paper, three simple and yet effective numerical algorithms are proposed to estimate the firing angle of the FC-TCR compensator. These algorithms that are based on Newton-Raphson, Bisection, and false position methods have proved their reliability and efficacy in estimating the firing angle under load and frequency variation. The effectiveness and robustness of the proposed methods are demonstrated via modeling an electrical power system of a practical hybrid ferry under MATLAB/Simulink environment, then the results are compared with the traditional technique.

Due to increasing environmental concerns associated with the fossil fuel consumption and greenhouse emissions by marine vessels, world is moving towards sustainable energy resources such as solar, wind and so on. Renewable energy sources are found out to be a significant source of energy as they are sustainable and clean as compared to traditional generation sources, for instance, the burning of fossil fuels, diesel generators, steam engines, etc. As solar energy is one of the cheapest, abundant and cleanest source of energy, therefore, it has the potential to be the most utilized source of energy along with energy storage systems (ESS) for future yachts and ferries. However, partial shading effect and intermittent nature of photovoltaic (PV) systems cause fluctuations in voltage that can potentially disturb the voltage profile, therefore may instigate instability in shipboard microgrids, if not properly managed. This paper, therefore, proposes a hybrid energy storage system (HESS) comprising of Lithium-ion (Li-ion) battery and ultra-capacitor having the capability to mitigate fluctuations caused by the partial shading effect in PV panels. The control system is based on frequency sharing approach in which high-frequency components are handled by the ultra-capacitor whereas low-frequency components are handled by the Li-ion battery. The proposed methodology is simulated using MATLAB/ SINULINK and various scenarios of power sharing are highlighted for the validation of the proposed scheme.

Partial shading affects the performance and reliability of thin-film and crystalline-silicon (c-Si) photovoltaic (PV) modules. In this paper, the thin-film and c-Si modules are experimentally benchmarked by introducing various partial shading patterns over the modules. More specifically, experiments are performed using SPISUN 5600 SLP-based test-rig. The benchmarking reveals that thin-film and c-Si technologies behave differently under the same shading patterns. Furthermore, thermographic images are also presented to explore the effect of partial shadingon both modules.

Over recent years, due to the fast expansion of power electronics technology onboard shipboard power systems (SPSs), harmonic contamination has become one of the main concerns. Moreover, the SPSs are characterized by heavy pulsed loads, which can draw a large amount of power in a short duration, which usually causes a voltage drop. If the latter exceeds the norms, a voltage collapse might occur and leads to the blackout of the ship. The contribution of this paper is to propose a combined topology, which consists of a hybrid active power filter (HAPF) connected to the switchboard via a series passive filter (hereafter called HAPF), and a parallel fixed capacitor-thyristor controlled reactor (FC-TCR) to overcome the aforementioned deficiencies of the SPS. Based on the model predictive control (MPC) and synchronous reference frame technique (SRF), the HAPF estimates the harmonics of the system and counter them, while the FC-TCR is designed to act as a low-pass filter and a reactive power compensator to enhance the stability and reduce the distortion of the voltage. The modeling and control of the proposed topology are presented. Furthermore, the voltage stability analyses of the SPS are conducted. Finally, the performance of the proposed topology is carried out under MATLAB/Simulink environment, and the results demonstrate the efficacy of the HAPF and the FC-TCR in suppressing harmonics and improving the voltage stability of the SPS.