1) A three-phase substation transformer operating at 34.5kV is loaded to
24 MVA. What is the per-phase current? (assume balanced
conditions)
2) If the current calculated above lags the voltage by 30°, what is the
breakdown of active and reactive loading on the transformer? (assume
balanced conditions)
1) A three-phase substation transformer operating at 34.5kV is loaded to 24 MVA. What is the...
A three-phase Y-A transformer is rated 225-kV:24-kV, 400 MVA and has a single-phase equivalent series reactance of 6.08 ? as referred to its high-voltage terminals. The transformer is supplying a load of 375 MVA at 0.89 power factor leading at a voltage of 24 kV (line to line) on its low-voltage side. It is supplied from a feeder whose impedance is 0.17 +/2.2 ? connected to its high-voltage terminals. For these conditions, calculate (a) the line-to-line voltage at the high-...
Question I The rating of a three phase three winding transformer are: Y-connected 10 KV 40 MVA Secondary Y-connected 22 KV 40 MVA A-connected 4 KV 15 MVA Primary Tertiary Neglecting winding resistance and exciting current, the per unit leakage reactance are: Mps 9.6 % pu on 40 MVA, 11022 KV xm = 7.2 % pu on 40 MVA, I 10/ 4 KV Xsti: 12 % pu on 40 MVA, 22/ 4 KV Determine the era nyimpedances of the transformer...
(30) Assume that a distribution substation, shown below, has a 4000 kVA 69/12.47 kV LTC 4) transformer feeding a three-phase four-wire 12.47 kV distribution system. The transformer has a reactance of 0.065 pu. Assume that fault impedance is 40 Q and that the maximum and minimum power generations of the system are 600 and 360 MVA, respectively. Use 1 MVA as the three-phase power base: a) Under the maximum (system) power generation conditions, determine the available three- phase, L-L, and...
(30) Assume that a distribution substation, shown below, has a 4000 kVA 69/12.47 kV LTC 4) transformer feeding a three-phase four-wire 12.47 kV distribution system. The transformer has a reactance of 0.065 pu. Assume that fault impedance is 40 Q and that the maximum and minimum power generations of the system are 600 and 360 MVA, respectively. Use 1 MVA as the three-phase power base: a) Under the maximum (system) power generation conditions, determine the available three- phase, L-L, and...
Outcome 2. Assume you need to size voltage regulators for a distribution substation transformer. A copy of the transformer nameplate is given on the back. Assume your utility allows this transformer to run 20% overloaded for 4 hours a day. Part 1 Review the nameplate and provide: 1. OA Rating MVA 14 2. Low side voltage 14.3 kV Part 2 Recommend a three-phase voltage regulator by giving its capacity and line current ratings for a wye-wye connection. Power Rating (kVA):...
5. Consider the one-ine diagram shown below. The three-phase transformer bank is made up of three identical single-phase transformer, each specified by X1-0.004 Ω (on the high-voltage side), negligible resistance and magnetizing current, and turns ratio N2/N,-10. The transformer bank is delivering is delivering 110MW at 0.9 power factor leading to a substation bus voltage is 230kV. Determine the reactive power supplied by the source. (3.47) whose To rest of the system Generator ΔΥ 230-kV substation bus Step-up transformer bank...
3) A two-winding transformer, three phase, 345/230 kV has a single phase capacity of 500 MVA: (a) Determine the total 3-phase capacity, if it is connected as Auto-XMR (b) Determine the voltage and current capacity per each phase Js. LI V, s, V
A 400-MVA, 200-kV/20-kV, three phase Y-Y transformer has an equivalent series impedance of ZTL = 0.012 + 20.0162 per phase referred to the low-voltage side (secondary side). The transformer is supplying a three-phase load of 300-MVA, 0.8 power factor lagging at terminal voltage of 20 kV (line-to-line) on its low-voltage side (secondary side) as shown in Fig. 22. The primary is supplied from a transmission line with an impedance of ZL = 0.5 + j1.0 per phase. The line-to-neutral load...
Please show detailed steps. Thanks
Problem # 1: Three Phase Power [35 points] A three-phase substation bus supplies three wye-connected three phase loads that are connected in parallel through a three-phase feeder with an impedance of 0.3 30 per phase Load 1 draws 75kVA at 0.866 lagging power factor, load 2 draws 45 kW at 0.70 leading power factor and load 3 draws 20 kVAR at 0.85 lagging power factor. The line-line voltage at the load is 460V Take the...
Bus A Bus B R1 TI ine 1 20% 80% line 2 T2 R2 110 kV 11 kV The fault is located at point F, which is 20% of the total line 2 length from Bus B Fault MVA 1524.20471 Three-phase fault level in MVA at bus A SPFL (kA) 8 MVA1 MVA2 X1 (96 X2 (96) R1 (2) R2 (Q) z' (Q) Zo (2) Rf (Q) Single phase to ground fault level (kA) at bus A Transformer 1 MVA...