Reference no: EM132377489

Subject-Electrical Engineering

You have one calculation question related to power electrical circuit. Just write and explain each step calculation to help me understand to check it’s correct or not

You have the calculation question which is related to power electrical circuit

Power Systems Operation and Protection

The inrush current is usually limited by installing an inductance in series with the capacitor bank as shown in Figure 3. In this figure, the capacitor bank is shown by C. L_eq and CB represent the equivalent inductance of the network and the circuit breaker, respectively. The needed inductance to limit the inrush current is shown by L.

Parameters of the above figure are:

Q_c,3ø = capacity of the capacitor bank = 20 MV A

V_L-L = phase to phase voltage = 63 kV

l_sc,3ø = Equivalent short circuit current at the capacitor location = 40 kA

I_max,CB = Maximum current capability of each circuit breaker = 8 kA

ƒ= Frequqency of the network = 50 Hz

1) By using l_sc,3ø , calculate the value of L_eq (H). By using Q_c,3ø , calculate the equivalent capacitor on each phase.

2) At first, the circuit breaker is open. Calculate the inrush current when the capacitor bank is switched on ( CB1, is closed). Is a series inductance (L) necessary in this case? If yes, calculate its corresponding value. (Note: for calculations, consider the worst case scenario. It means that CB is switched on when the source voltage is at its maximum value.)

3) Usually, more than one capacitor bank are used in parallel in the substations as shown in Figure 1 and Figure 4. Calculate the inrush current when the second capacitor is switched on while the first capacitor bank is already energized. Is a series inductance (L) necessary in this configuration? If yes, calculate the corresponding value. (Note: in this case, you can neglect the current from the upstream network.)