This thesis advances the state of the art in modeling electric machines in electro-magnetic transient simulation programs, particularly in real-time digital simulators. A new tool, developed in this thesis, expands the application of real-time digital simulators to closed-loop testing of protection relays designed to protect synchronous machines during internal faults. To evaluate the inductances of synchronous machines, a winding function approach was developed in this thesis which is capable of taking into account both the actual distribution of windings and the shape of the pole-arc. Factors such as MMF drop in the iron and effects of slots are compensated by evaluating the effective permeance function of the machine using experimentally measured values of d-, q- and 0- axis inductances. In this winding function approach, the effects of magnetic saturation are also included by considering the actual distribution of magneto-motive force in each loading condition of the machine. The inductances of an experimental machine are evaluated using this approach and validated using the finite-element method and laboratory measurements. This thesis also proposes an embedded phase-domain approach for time-domain simulation of the machine model in electromagnetic transients programs. The approach significantly improves the numerical stability of the simulations. Special numerical techniques are introduced, which speed up the execution of the algorithm as needed for real-time simulation. The machine model is validated in healthy and faulted conditions using simulations and laboratory experiments. Effects of damper grid representation on simulating turn-to-turn faults are investigated. The capability of this new real-time synchronous machine model in closed-loop testing of synchronous machines ground- faults protection relays is clearly demonstrated.

This thesis advances the state of the art in modeling electric machines in electro-magnetic transient simulation programs, particularly in real-time digital simulators. A new tool, developed in this thesis, expands the application of real-time digital simulators to closed-loop testing of protection relays designed to protect synchronous machines during internal faults. To evaluate the inductances of synchronous machines, a winding function approach was developed in this thesis which is capable of taking into account both the actual distribution of windings and the shape of the pole-arc. Factors such as MMF drop in the iron and effects of slots are compensated by evaluating the effective permeance function of the machine using experimentally measured values of d-, q- and 0- axis inductances. In this winding function approach, the effects of magnetic saturation are also included by considering the actual distribution of magneto-motive force in each loading condition of the machine. The inductances of an experimental machine are evaluated using this approach and validated using the finite-element method and laboratory measurements. This thesis also proposes an embedded phase-domain approach for time-domain simulation of the machine model in electromagnetic transients programs. The approach significantly improves the numerical stability of the simulations. Special numerical techniques are introduced, which speed up the execution of the algorithm as needed for real-time simulation. The machine model is validated in healthy and faulted conditions using simulations and laboratory experiments. Effects of damper grid representation on simulating turn-to-turn faults are investigated. The capability of this new real-time synchronous machine model in closed-loop testing of synchronous machines ground- faults protection relays is clearly demonstrated.

Distance relays due to their selectivity and operating speed are used in HV/EHV line protection. The dynamic nature of Mho characteristic, which happens to be most primitive technique in line protection implemented with distance relaying, is built by using the measurement of local voltage and current signals. These signals have been influenced substantially by fault resistance and the source impedance feeding the line. In case of different generation sources, the source impedance and fault characteristic also change accordingly. Environmental benefit of wind turbine technology is making it a potential source of energy. These wind turbine-generating units (WTGU) use rugged induction/synchronous machines along with power electronics converters as controlling equipment. This gives a new challenge to distance relays, as the fault current contribution of these sources depends on the converter operational principle. In this thesis a typical wind farm of Indian systems are modeled in an IN-HOUSE tool developed as part of fault analysis on wind farm system. Directly connected and front-end converter based wind turbines with their interconnections are modeled in this simulation tool. Fault voltage and current waveforms are obtained for all types of wind turbine-generating units with both radial and LILO (Loop in Loop out) connection. PSCAD based modeling has been done for DFIG type of wind turbines. The fault waveforms are generated to evaluate relay performance. Five case studies having both Radial and Loop in Loop out (LILO) connection of wind farms are simulated. These case studies generate approximately 20000 cases, which are analyzed for distance relay performance studies. In addition, the analysis is further verified on relay hardware having three characteristics, namely Self Polarized Mho (SPM), Quadrature Polarized Mho (QPM) and Quadrilateral (QUAD) characteristics. The detailed studies are carried out in this thesis to ensure and suggest the system operators with appropriate relay characteristics to be used for transmission line protection in the case of wind farms interconnected to Grid. Based on the studies carried out in the thesis, LILO connection has no impact on distance relay characteristic. In radially connected wind farms, grid side relay will operate reliably for all types of faults. It has been recommended in the thesis that wind farm side distance relay characteristics should be adjusted based on the types of wind turbines (Type-1, Type-2, Type-3 and Type-4). Based on the investigations carried out in the thesis, voltage based phase selector has been recommended for Type-4 WTGU based wind farms.

Standard IEC 61850-9-2 definuje přenos vzorkovaných měřených hodnot (sampled measured values, SMV) prostřednictvím sítě Ethernet a využití SMV získaných ze slučovacích jednotek nebo přístrojových transformátorů. Implementace IEC 61850-9-2 závisí na vlastnostech datového souboru, jakými jsou časová synchronizace, počet vzorků a časový interval. Dizertační práce je zaměřena na algoritmy chránění a analýzu vlivu standardu IEC61850-9-2LE na fyzická zařízení ochran s analogově/digitálními vstupními daty o proudu a napětí. S ohledem na narůstající míru interakce mezi fyzickými zařízeními a komunikačními prvky byl navržen test pro analýzu komunikace pro rozvodnu využívající konvenční metody (analogové vstupy) a metody digitální založené na standardu IEC 61850-9-2. Práce dále popisuje funkci slučovací jednotky využívající standard IEC61850-9-2LE. Navržená metoda definuje zdroj SMV a analyzuje přenos dat. V rámci práce byl za využití softwaru Matlab naprogramován algoritmus ochrany. Vytvořený model je schopen vyhodnotit vliv harmonického zkreslení na funkci digitálních ochran a vliv přesycení proudového transformátoru na distanční ochranu. V práci jsou zhodnoceny i možnosti zrychlení testování systémů chránění s využitím neuronové sítě. Závěrečná kapitola se zabývá aplikacemi v reálném čase, využívajícími data z rozvodny v blízkosti Vysokého učení technického v Brně. K přenosu dat z rozvodny do univerzitní laboratoře je zde využíváno SMV přenášených optickým kabelem o délce 16 km. Aplikace je vytvořena v programu Matlab a je schopna číst data z ethernetového portu, dekódovat je, převést z formátu ASCII do desítkové soustavy a poté vykreslit průběhy proudu a napětí. Mezi vlastnosti aplikace se řadí jednoduchost použití, schopnost implementace funkcí distanční ochrany, výpočet RMS hodnot proudu a napětí a harmonického zkreslení, harmonická analýza prostřednictvím rychlé Fourierovy transformace a výpočet impedance poruchové smyčky. Všechny výpočty běží v reálném čase a provedena je i citlivostní analýza modelu.