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Electric Power Systems Exam #3: 01/09/2020 1° Part Exercise 1 In the figure bellow a three -phase demand (D) is supplied by a three -phase synchronous generator ( SG) through the electric line L. The demand is supplied at line-to-line voltage of 𝑉𝑠𝑢𝑝𝑝𝑙𝑦 = 5100 + 50 ∙ 𝑵 [V] and absorbs 𝑃𝐷 = 300 + 20 ∙ 𝑵 [kW] with a leading power factor cos 𝜑𝐷 = 0.97. The electric line is characterized by 𝑅𝑙 = 3 Ω and 𝑋𝑙 = 10 Ω. The synchronous generator nameplate specifies the following data: Nominal electrical power 600 kVA Nominal line-to-line voltage 5.4 kV Maximum phase-to-ground emf 5.9 kV Maximum turbine power 550 kW Stator winding resistance 5 Ω Synchronous reactance 21 Ω Stator phases connection D Determine: 1. the real and reactive power supplied by the synchronous generator to the grid and the line-to-line voltage at the synchronous generator’s terminals; 2. the emf 𝐸0 and the load angle (𝛿) of the synchronous generator; 3. check the capability curve of the synchronous generator in the given operating conditions; 4. determine the maximum reactive power ( 𝑄𝑔max ) that the machine can produce when operated at the electrical power previously obtained. In the above data, N is the last number of the student’s Person Code/Codice Persona (e.g. if Person Code is 10381486 then N = 6); Please substitute accordingly. P su Exercise 2 Consider the following electrical network: Line xl [p.u.] L1 0.025+0.001∙N L2 0.05 Generator Operating real power: PG Operating voltage: [p.u.] [p.u.] G 4 1.02 Demand Absorbed real power: PD Power factor [p.u.] [-] D1 6+0.1∙N 0.94 - lagging D2 0.5 0.94 - leading The External Grid (Ext Grid) is modeled as an infinite power generator and imposes at its busbars a voltage of 1.0+0.01∙N p.u.. After careful examination of the network topology: 1. determine the bus…