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This version is available at https://strathprints.strath.ac.uk/64860/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Strathprints administrator: strathprints@strath.ac.ukThe Strathprints institutional repository (https://strathprints.strath.ac.uk) is a digital archive of University of Strathclyde research outputs. It has been developed to disseminate open access research outputs, expose data about those outputs, and enable the management and persistent access to Strathclyde's intellectual output. Abstract-As the capacity of all-electric ships (AES) increases dramatically, the sudden changes in the system load may lead to serious problems, such as voltage fluctuations of the ship power grid, increased fuel consumption and environmental emissions. In order to reduce the effects of system load fluctuations on system efficiency, and to maintain the bus voltage, we propose a hybrid energy storage system (HESS) for use in AESs. The HESS consists of two elements: a battery for high energy density storage and a superconducting magnetic energy storage (SMES) for high power density storage. A dynamic droop control is used to control charge/discharge prioritisation. Manoeuvring and pulse loads are the main sources of the sudden changes in AESs. There are several types of pulse loads, including electric weapons. These types of loads need large amounts of energy and high electrical power, which makes the HESS a promising power source. Using Simulink/Matlab, we built a model of the AES power grid integrated with a SMES/battery to show its effectiveness in improving the quality of the power grid.  Index Terms--All-electric ship (AES), hybrid energy storage system (HESS), superconducting magnetic energy storage (SMES), pulse load.

As the pulse power and high power microwave source technologies gradually matured, technologies for enhancing the output capacities of high power microwaves are becoming more and more attractive. In this paper, two different methods for the increasing of X band microwave powers are discussed: diplexers based on microwave filter and photonic crystal. For the case of diplexer based on microwave filter, the dual channel X band microwaves transmit through the filters with high efficiencies, the polarization and radiation directions for the microwaves are the same. With the application of metal photonic crystal, the reflection and transmission of TE/TM polarized X band microwaves are realized simultaneously; thus, the dual channel microwaves have the same radiation direction. A pulse of 25 ns, 3.9 GW has been successfully obtained. However, according to the experimental results, the internal breakdown in these devices limits their power handling capacities when the peak power and pulse duration of the microwaves increase. In the end, several methods for enhancing the power handling capacities the diplexer have been proposed.

High-temperature superconducting magnetic energy storage systems (HTS SMES) are an emerging technology with fast response and large power capacities which can address the challenges of growing power systems and ensure a reliable power supply. China Electric Power Research Institute (CEPRI) has developed a kJ-range, 20kW SMES using two state of art HTS conductors, BSCCO and YBCO tapes. This SMES system is used to compensate a power drop and a fluctuation in order to damp low frequency oscillations to increase stability of a power system. This paper presents an optimized design of the SMES system to achieve a maximum energy capacity. A voltage source converter using IGBTs is built and can be used to control the power flow between the SMES system and external circuits. A control system using a digital signal processor (DSP) and micro-programmed control unit (MCU) is constructed. SVPWM pulse modulation is used as a control strategy. The whole system was experimentally tested for compensation of power fluctuation within milliseconds in a dynamic power system simulation laboratory. The result validates the design and control circuit, and more importantly, the application capability of SMES systems in a power grid.

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