3 research outputs found
Symmetrical Fault Detection During Power Swing Based on dq-Wavelet Packet Entropy
No full textDistance relay trips unnecessarily under power swing condition and it is considered as the significant circumstance for power system blackouts. To prevent the hazard of misoperation of distance relay, a scheme is essential so as to block circuit breaker tripping during power swing and to detect a fault during power swing condition. In Power system faults, unsymmetrical faults are unbalanced signals which have negative & zero sequence components, and these sequence components help to identify the faults during the power swing. Whereas, these components are absent during symmetrical fault since power swing and symmetrical fault are balanced phenomena. Symmetrical fault detection under power swing condition is a critical issue. Hence, Power system protection due to symmetrical fault during power swing is difficult. In this regard, a proposed scheme based on Direct axis - Quadrature axis transformation and Wavelet packet entropy to identify symmetrical faults occurring with power swing is proposed. The proposed technique is investigated for various power swing and fault conditions on two-machine system, distribution system with distributed generation and WSCC 9-bus system using Matlab software. This scheme provides better results irrespective of various fault locations, fault inception angle, and power swing frequencies. This scheme can also detect asymmetrical faults with high impedance during power swing
Web Application Shielding
No full textIn the olden days computer networks were used for sending emails so there was no issue of security but now a days people who are using internet as sharing tool are hacking the financial products like credit cards, debit cards by hacking the pin numbers and passwords and are misusing the accounts. There are several threats for the online applications such as hacking, intrusion and so on. Nowadays, application security is rapidly being recognized as a top priority. The systems store and retrieve knowledge and it'll shield the information from unauthorized users, disclosure, modification or destruction. Systems can make sure that the users have the authority to access the information, load new knowledge, or update existing knowledge. It is a very huge and complex task to provide security for a web application. So to avoid such problems a Web Application Shielding with the help of encryption techniques can be developed. This prevents hackers from exploiting vulnerabilities. This provides a higher level of security
