The synchronous machine

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EXERCISES FOR ELECTRIC POWER SYSTEMS COURSE ENERGY DEPARTMENT, Electrical section Class 5 The Synchronous Machine Exercise 1 For a three-phase Y-connected, 1 MVA, 500 V, 50 Hz synchronous machine the open-circuit characteristic /g1831 /g2868/g3404 /g1858/g4666/g1835/g3032/g3051/g3030 /g4667, and the short- circuit characteristic, /g1835/g3046/g3030 /g3404 /g1858/g4666/g1835/g3032/g3051/g3030 /g4667, are given in the figure. The characteristics are referred to the line-to-ground voltage of the stator windings. The phase resistance of the synchronous machine is 0.01 Ω. Answer the following questions: 1. determine the phase synchronous impedance characteristic of the machine, /g1852 /g3046/g3404 /g1858/g4666/g1835/g3032/g3051/g3030 /g4667; 2. assuming the synchronous impedance constant and equal to the nominal value, determine the induced emf phasor ( /g1831 /g2868/g3364/g3364/g3364) for each of the below described load conditions, such that the voltage at the machine terminals is constant and equal to the nominal voltage of the machine: 2.1. the real power demand of the load is /g1842/g3005/g34040.6 MW and the power factor is: cos /g2030/g3005/g34040.9 – lagging ( RL load); cos /g2030/g3005/g34041 (R load) and cos /g2030/g3005/g34040.9 – leading ( RC load). 2.2. the load absorbs a reactive power of /g1843/g3005/g3404 0.2 Mvar with a power factor of cos /g2030/g3005/g3404 0 (L load); 2.3. the load injects a reactive power of /g1843/g3005/g3404 0.2 Mvar with a power factor of cos /g2030/g3005/g3404 0 (C load); 3. the external characteristics of the machine, /g1848/g3364/g3404 /g1858/g4666/g1835̅/g4667, considering the open-circuit voltage at the machine terminals equal to 500 V and the machine operating with constant excitation current and constant power factor of cos…