A 100 m diameter wind turbine drives an induction generator at a fixed speed through a...

 

 

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A 100 m diameter wind turbine drives an induction generator at a fixed speed through a gearbox of ratio 1:92. The induction generator is connected to a 20 kV, 50 Hz grid at the point of common coupling (PCC) via a transformer and an overhead line. The transformer rating is 3 MVA with a rated voltage of 0.96 kV on the LV side and 20 kV on the HV side. For the transformer, ukr is 6% and uRr is 1%. The 10 km long overhead line has a specific impedance of (0.253 + j0.2) ohms per phase. The grid is represented by an ideal voltage source behind the grid short circuit impedance. The grid short circuit capacity is 150 MVA, and its X/R ratio is 4. The four-pole induction generator rating is 3 MVA, with a rated voltage is 0.96 kV, and it has the following per phase equivalent circuit parameters Rs = 0.01 pu, Xs = 0.09 pu, Xm = 3 pu, Rr = 0.006 pu and Xr = 0.04 pu (all on machine base). The generator is compensated by a three-phase star-connected capacitor bank. If the grid voltage is 1 pu, and the wind turbine rotor is running at a fixed speed of 16.4 rpm: 1. Determine the capacitor susceptance (in pu), and the corresponding capacitance per phase (in Farads), which is required to correct the generator power factor to unity. Also determine the voltage (in pu), and the active and reactive power flows (in pu), that would be observed at: a. the generator terminals G, b. the HV terminals of the transformer, and c. the PCC. Determine the capacitor susceptance (in pu) and the corresponding capacitance per phase (in Farads), which is required to maintain the generator voltage at 1 pu. Also determine the voltage (in pu), and the active and reactive power flows (in pu), that would be observed at: a. the generator terminals G b. the HV terminals of the transformer, and c. the PCC. A 100 m diameter wind turbine drives an induction generator at a fixed speed through a gearbox of ratio 1:92. The induction generator is connected to a 20 kV, 50 Hz grid at the point of common coupling (PCC) via a transformer and an overhead line. The transformer rating is 3 MVA with a rated voltage of 0.96 kV on the LV side and 20 kV on the HV side. For the transformer, ukr is 6% and uRr is 1%. The 10 km long overhead line has a specific impedance of (0.253 + j0.2) ohms per phase. The grid is represented by an ideal voltage source behind the grid short circuit impedance. The grid short circuit capacity is 150 MVA, and its X/R ratio is 4. The four-pole induction generator rating is 3 MVA, with a rated voltage is 0.96 kV, and it has the following per phase equivalent circuit parameters Rs = 0.01 pu, Xs = 0.09 pu, Xm = 3 pu, Rr = 0.006 pu and Xr = 0.04 pu (all on machine base). The generator is compensated by a three-phase star-connected capacitor bank. If the grid voltage is 1 pu, and the wind turbine rotor is running at a fixed speed of 16.4 rpm: 1. Determine the capacitor susceptance (in pu), and the corresponding capacitance per phase (in Farads), which is required to correct the generator power factor to unity. Also determine the voltage (in pu), and the active and reactive power flows (in pu), that would be observed at: a. the generator terminals G, b. the HV terminals of the transformer, and c. the PCC. Determine the capacitor susceptance (in pu) and the corresponding capacitance per phase (in Farads), which is required to maintain the generator voltage at 1 pu. Also determine the voltage (in pu), and the active and reactive power flows (in pu), that would be observed at: a. the generator terminals G b. the HV terminals of the transformer, and c. the PCC.

Answer rating: 100% (QA)

athe generator terminals G A Capacitor susceptance required to correct the generator power factor to unity is 0037 pu The corresponding capacitance per phase required is 1542 F B The voltage at the ge... View the full answer