Biblio

The metal oxide arrester (MOA, shortly) is installed on the line side of the substation, which is the first line of defense for the overvoltage limitation of lightning intrusion wave. In order to deeply limit the switching overvoltage and cancel the closing resistance of the circuit breaker, the arrester is replaced by the controllable metal oxide arrester (CMOA, shortly) in the new technology. The controllable switch of CMOA can be mechanical switch or thyristor switch. Thyristor switches are sensitive to the current and current change rate (di/dt) under lightning intrusion wave. If the switch cannot withstand, appropriate protective measures must be taken to ensure the safe operation of the controllable switch under this working condition. The 1000kV West Beijing to Shijiazhuang UHV AC transmission and transformation expansion project is the first project of pilot application of CMOA. CMOA were installed at both ends of the outgoing branch of Dingtai line I. In order to study the influence of lightning intrusion wave on the controllable switch of CMOA, this paper selected this project to simulate the lightning stroke on the incoming section of Dingtai line I in Beijing West substation in the process of system air closing or single-phase reclosing, and obtained the current and di/dt of the controllable switch through CMOA under this working condition. Then the performances of mechanical and thyristor control switches were checked respectively. The results showed that the mechanical switch could withstand without protective measures. The tolerance of thyristor switch to i and di/dt exceeded the limit value, and measures should be taken to protect and limit it. In this paper, the protection measures of current limiting reactor were given, and the limiting effect of the protection measures was verified by simulation and test. It could fully meet the requirements and ensure the safe operation of thyristor controllable switch.

Due to the frequent usage of online web applications for various day-to-day activities, web applications are becoming most suitable target for attackers. Cross-Site Scripting also known as XSS attack, one of the most prominent defacing web based attack which can lead to compromise of whole browser rather than just the actual web application, from which attack has originated. Securing web applications using server side solutions is not profitable as developers are not necessarily security aware. Therefore, browser vendors have tried to evolve client side filters to defend against these attacks. This paper shows that even the foremost prevailing XSS filters deployed by latest versions of most widely used web browsers do not provide appropriate defense. We evaluate three browsers - Internet Explorer 11, Google Chrome 32, and Mozilla Firefox 27 for reflected XSS attack against different type of vulnerabilities. We find that none of above is completely able to defend against all possible type of reflected XSS vulnerabilities. Further, we evaluate Firefox after installing an add-on named XSS-Me, which is widely used for testing the reflected XSS vulnerabilities. Experimental results show that this client side solution can shield against greater percentage of vulnerabilities than other browsers. It is witnessed to be more propitious if this add-on is integrated inside the browser instead being enforced as an extension.