1,720,983 research outputs found
Active Damping Poles Repositioning for DC Shipboard Microgrids Control
No full textMedium Voltage Direct Current will be the enabling technology in the shipboard power systems of tomorrow. In such grids, the stability assessment results of paramount importance, as the pervasive presence of power converters can lead to system instability. In presence of perturbations, dynamic interactions between high bandwidth controlled converters and LC filtering stages can indeed provoke unstable behaviors, thus the consequent ship blackout. By adopting the Eigenvalues method, the paper performs the small-signal stability analysis on a DC shipboard power system. Once recognized a system perturbation (i.e. generating converter disconnection) as destabilizing, the virtual Active Damping effect is consequently tuned to re-establish the DC grid stability. Poles repositioning in the left-half plane and dynamics simulations will justify the designed control's capability
Optimized Tuning for Flexible and Resilient Control of Zonal DC Microgrids on Ships
Full text linkFlexibility and resiliency are among the main features of next-generation zonal DC microgrids on ships. These paramount characteristics are enabled by the huge penetration of power electronics interfaces, whose presence is beneficial for the grid controllability. Conversely, the interactions among controlled converters and filtering stages can possibly trigger unstable behaviors, thus the ship blackout. Although DC systems are designed to ensure the stability in the operating conditions, the risk of instability is anyway not negligible, especially after faults or undesired disconnections. In this paper, an advanced Power Management System (PMS) is conceived to reconfigure the control parameters in order to avoid the instability. This control tuning is performed by integrating into the PMS an optimization procedure. The latter is able to maintain the system stability without any load shedding action, while limiting the dynamics performance worsening. The stable reconfiguration capability extends the flexible and resilient operation of zonal DC grids
Stability-oriented filter design optimization in cascade-connected MVDC shipboard power system
No full textVoltage stability is one of the issues that need to be tackled before successfully exploiting innovative Medium Voltage DC distribution systems. Focusing on a cascade-connected MVDC power system (i.e. a feeder DC-DC converter supplying a load controlled DC-DC converter), the paper presents a filter design optimization process. The proposed procedure allows minimizing the DC filtering stage capacitor size, assuring at the same time the compliancy with voltage ripple requirements and the system voltage stability for a given load-side control bandwidth
A multi-model methodology for stability assessment of complex DC microgrids
No full textThe system stability is a paramount requirement to be attained in islanded DC microgrids. Even more crucial the obligation in MVDC shipboard power systems, where instability means ship blackout. The destabilizing interactions between high bandwidth controlled converters and LC filters are investigated to ensure the on board safe operation. Albeit the stability analysis is well-proven in case of few filtered power converters, the study becomes prohibitive in case of complex shipboard DC microgrids. To overcome this bottleneck, the paper defines a smart procedure to assess the small-signal stability in a multi-converter DC distribution, where several are the interacting controlled converters as well as the filtering stages. Basing on the Eigenvalues Based Method, the procedure can detect in advance the instability by analyzing nonlinear/linearized models, while the dynamics effect is testified on PSCAD switching simulations. A step-by-step comparison between the model's outputs can confirm the procedure validity, thus proving its capability in assessing the DC system stability
Strategies for Preserving the Battery SOC in DC Shipboard Power systems
No full textNowadays, the energy storage solutions are reaching a more prominent role when integrated in DC shipboard power systems. Among others, batteries and supercapacitors are already capable of assisting the traditional on-board energy resources, both during normal operation (e.g. fuel consumption optimization, peak shaving, pulsed loads supply) and in critical situations. When a main source of energy goes out of service, the remaining online sources and the storage are to be proficiently managed, thus ensuring enough power to the vital loads without outages. In this scenario, the power sharing between the storage systems gets a notable importance, as an accurate load subdivision can actually extend the power-on time. The paper investigates different options to manage the Battery Energy Storage Systems of a DC shipboard power system. Two batteries are onboard installed to temporarily support the loads supply if a generating system disconnection occurs. Three power sharing profiles are investigated to identify the best solution in preserving the State of Charge of batteries
Open Challenges in Future Electric Ship Design: High-Frequency Disturbance Propagation in Integrated Power and Energy Systems on Ships
No full textShipboard power systems have made great progress since Jacobi's experiment in the late 1830s (i.e., the first electric propelled boat). Today, the shipboard power system design process is facing significant changes, mostly due to the improvements both in power electronics and battery technology. (For instance, the MF Ampere entered into service in 2015 as the world's first electric battery-powered passenger and car ferry.) Moreover, the power systems sector is also undergoing significant changes due to both the ever-increasing requirements of ship owners and the enforcement of recent efficiency and pollution regulations. Currently, power electronics converters increase in both power and number in a modern Integrated Power and Energy System (IPES), exploiting different power system architectures
Design of Zonal Electrical Distribution Systems for Ships and Oil Platforms: Control Systems and Protections
Full text linkComplex energy vessels such as large platforms or drillships require more efficient use of electrical power. As shipboard electrical systems become larger, problems and limits arise with the ac distribution architecture. Hybrid ac/dc onboard distribution systems are today available, which provide higher efficiency and redundancy. IEEE Std. 1662, 1709 and 1826 set technical rules and recommendations for the design of hybrid ac/dc shipboard electrical systems. Among these, zonal electrical distribution systems (ZEDS) are considered a next technological evolution, as they provide optimal power sharing (and energy storage) along with high reliability
The SSE-ID Card of Ships in the Sustainable Maritime Framework
No full textNowadays, the worldwide implementation of shore-to-ship connection paradigm is hindered by the large variability of requirements on the ships to be powered. In order to solve this issue, a standardized form must be conceived for defining all the characteristics. The paper wants to presents the shore-side electricity (SSE) related information as encoded in an electronically registered ID card (the SSE-ID) of all the ships subjected to cold ironing obligation. As finalized in the IEEE 45.1, the format of SSE-ID is anticipated to facilitate the SSE-connectivity procedures in all the equipped ports
The SSE-ID Card of Ships in the Sustainable Maritime Framework
Full text linkNowadays, the worldwide implementation of shore-to-ship connection paradigm is hindered by the large variability of requirements on the ships to be powered. In order to solve this issue, a standardized form must be conceived for defining all the characteristics. The paper wants to presents the shore-side electricity (SSE) related information as encoded in an electronically registered ID card (the SSE-ID) of all the ships subjected to cold ironing obligation. As finalized in the IEEE 45.1, the format of SSE-ID is anticipated to facilitate the SSE-connectivity procedures in all the equipped ports
Real-time monitoring and control system for Trieste University Campus electrical distribution grid
No full textThe growing integration needs in the electrical systems are increasingly demanding more control also on the distribution network. This can be satisfied by introducing advanced control on the small and medium distribution grid sites and, in general, introducing electronic devices for voltage and power-flow control. All these concepts are commonly summarized with the Smart Grid term and putting the emphasis on system management through the Micro Grid paradigm. In this context the distribution network of a university campus, with one connection point to the distribution network, can be an interesting test bed. In this paper the status and the evolution of the Trieste University Campus distribution network is presented, showing also the adopted technical solutions
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