Absfracr -The US Navy is IooLing for methods to marimhe the survivabilit). of combat ships during battle conditions. A shipboard power distribution system is a stiff, isolated power system that is minerable to system transients. Power quality problems, such as voltage sags, which arise due to a fault or a pulsed load, can cause interruptions of critical loads. Critical loads include radar systems, pumps and weapon systems. A series voltage injection type flywheel energy storage system is proposed to mitigate voltage sags and marimhe the survivability of the ship. The basic circuit consists of nn energy storage system, power electronic interface and a series injection transformer. In tbu case the energy storage system consists of a flywheel conpled to an induction machine. The flywheel stores energy in the form of kinetic energy nnd the induction machine is used for energy converslon. The power elecironic interface facilitates the bidirectional now of power for charging and direhargiog the flywheel through the induction machine. The stored energy is used for sag correction when the critical load sees a voltage sag. ludired field oriented control with space vector PWM is used to control the induction machine. Sinnsoldal PWM is used for conbolliag the power system side converter. This paper presents the madeling, simulation and andysi. ?f B flynheel energy storage system With a power converter interface using PSCADEMTDC. 0-7803-7817-2/03/$17.W 02003 IEEE

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Shunt capacitor banks (SCBs) are used in the electrical industry for power factor correction and voltage support. Over the years, the purpose of SCBs has not changed, but as new dielectric materials came to market, the fusing practices for these banks changed from externally fused to internally fused, fuseless, and finally to unfused [1]. This paper gives a brief overview of the four most common types of SCBs. What are the differences between them? Which is the best one to use? What type of protection is best suited for each bank configuration?The paper provides a quick and simple way to calculate the out-of-balance voltages (voltage protection) or current (current protection) resulting from failed capacitor units or elements. While the identification of faulty capacitor units is easy with an externally fused bank, it is more complex with the other types of fusing, making maintenance and fault investigation difficult. This paper presents a novel method to identify the faulted phase and section in capacitor banks.978-1-4244-6075-5/10/$26.00 ©2010 IEEE

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