NPS shall include all features of conventional relays, protective devices, relay panels for generator, generator transformer, unit transformer, and station transformer Numerical protection system (NPS) shall mean the protection terminals wherein the analog to digital conversion of the input variables takes place immediately after the input transformers and all further processing of the resulting numerical signals shall be performed by microprocessors and controlled by programs. Each subcase contains a complete protection device with DC/DC converter for power supply, Potential, and current transformers, an A/D converter, computer chips, a watchdog circuit, and trip relays.
The generator protection and synchronizing cubicles will be delivered in fully wired and tested cubicles, ready for connection. The mechanical turbine and generator protection are independent of electrical protection. The task of the electrical unit protection is detecting electrical failures and inadmissible operation of the generator, generator bus bar, excitation system, generator transformer, and another existing transformer (Station transformer, unit auxiliary transformer) and disconnect faulty circuits with speed and certainly without interference healthy circuits.
Generator Transformer Protection System full diagram based on SIPROTEC Siemens Relays
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Study of an MV industrial network and use of the protection plan: Calculation/ verification of fault current, Choosing protection function according to the application (substation, busbar, transformer, etc …)
Introducing MV protection principles: The protection functions, The principles of discrimination, Measurement sensors.