Lab_10

Shown are two buses connected via a transmission line. Connected to Bus 1 is a generator(modelled as a voltage source V1), and to Bus 2 is a generator( with Voltage V2) and a load. The line impedance Z = R + jX is not known. Three-phase load is forecasted as 100MW + 60MVar. Generator at Bus 2 is scheduled to deliver 40MW and its excitation is adjusted for the machine to deliver 55 MVar. Voltage at Bus 1 is 241 KV angle 10 deg, while voltage at bus is 230 kV; use V2 as the reference for all angles. 1. What is the current (RMS) in amperes drawn by the load connected to Bus 2? 2. How much real power (in MW) is delivered by the generator connected to Bus 1? 3. What is the total real power loss along the line, in percent of the load? 4. What is the X/R Ratio of the line impedance?

1. A 69-kV, three-phase short transmission line is 16 km long. The line has a per phase series impedance of 0.125+j0.4375 Ω per km. Determine the sending end voltage, voltage regulation, the sending end power, and the transmission efficiency when the line delivers (a) 70 MVA, 0.8 lagging power factor at 64 kV. (b) 120 MW, unity power factor at 64 kV. Use lineperf program to verify your results. 2. A three-phase, 765-kV, 60-Hz transposed line is composed of four ACSR, l,431,000-cmil, 45/7 Bobolink conductors per phase with flat horizontal spacing of 14 m. The conductors have a diameter of 3.625 cm and a GMR of 1.439 cm. The bundle spacing is 45 cm. The line is 400 km long, and for the purpose of this problem, a lossless line is assumed. (a) Determine the transmission line surge impedance Zc, phase constant ß, Wavelength, the surge impedance loading SIL, and the ABCD constant. b) The line delivers 2000 MVA at 0.8 lagging power factor at 735 kV. Determine the sending end quantities and…

A balanced delta-connected load has phase impedances of 4+j3 Ohms. It is connected to balanced transmission lines, with Vab = 1.5kV @ 15 degrees. a) What is the current through each of the load phases? b) What is the current through each of the transmission lines? c) Which ACSR cable should be used for these transmission lines to give a 20% current rating margin for this load?

A 400V three-phase, four wire system has the following loads connected:   Phase 1: load impedance Z1 = 40 + j15 Ω Phase 2: load impedance Z2 = 60 Ω Phase 3: load impedance Z3 = 15 – j20 Ω I am just looking for the working out for phase 2 - please ignore the other phases    The line and phase voltages for all phases (including phase angles) The line and phase currents for all phases (including phase angles) The neutral current (including phase angle)

A balanced delta connected load of 13+j16 ohm per phase is connected at the end of a three-phase line. The line impedance is 2+j11 ohm- per phase. The line is supplied from a three-phase source with a line-to-line voltage of 207.85 Vrms. Taking phase "a" voltage Va as reference, determine the following: (a) Current in phase a. (b) Total complex power supplied from the source. (c) Magnitude of the line-to-line voltage at the load terminal.

20/ For balanced three phase star connected load, the phase angle difference between VR and VY is 30 degrees.  Select one: True False

The one-line diagram of a three-phase power system is as shown in the figure attached. Impedances are marked in per unit on a 100-MVA, 400-kv base. The load at bus 2 is S(sub 2) = 15.93 MW - j33.4 Mvar, and bus 3 is S(sub 3) = 77MW + j14 Mvar. I tis required to hold the voltage at bus 3 at 400 angle 0 degrees kV. Working in per unit, determine the voltage at buses 2 and 1.

4) State the relation between line and phase values of voltage and current for 3-pha se DELTA connected load .state the equation for active, reactive power consumed by 3-phase load.

The power system insulation problem involves a. Capacitance of earth and subsequent grounding b. Selection of basic insulation level of system equipment c. Determination of single phase line insulation d. Determination of three phase line insulation Clear my choice

Type your question here Explain the terms, connected load, load factor, plant use factor, diversity factor.

Question #1: The following unbalanced line-to-ground voltages are applied to the balanced Y-load shown in the following figure: C a + Vea ag ell + T, Figure 1: Balanced Y-load supplied by an unbalanced voltage source. Vag = 10020°, Vpg = 754180°, and Veg with neutral impedance Zn = j1 n. 50290° volts. The Y-load has Zy = 3 + j4 N per phase Calculate the line currents Ia, Ib, and I, using symmetrical components.

Let the three-phase electrical system be illustrated in Figure . Knowing that its phase sequence is ABC and that Vcb=380∠135°V, determine the following: a) The value of the line currents demanded by each of the loads and supplied by the source. b) The power and power factor of each load and source. c) The power of the capacitor bank that must be installed to correct the power factor to 0.95 lagging. d) The currents supplied by the source after installing the capacitor bank. e) The percentage reduction of the total apparent power supplied by the source after installing the capacitor bank.

single circuit three-phase line, 60 Hz, 18 km has a total resistance and inductive reactance of 4.242 ohm and7.451 ohm per phase respectively. The line delivers 2500 kW to a balanced load at 11 kV. (1) determine the sending-end voltage when the power factor is (i) 80% lagging, (i) unity, and (ii) 90 % leading, (2) draw the phasor diagrams of the line at the above (3) determine the voltage regulation of the line at the above power factors.

Consider a DVR compensated single phase system as shown below. a) Without DVR, find the load terminal voltage (VL) if line resistance (Rs) is negligible with Xs = j0.5 pu , ZL = 0.8 + j0.5 pu and Vs= 1pu with angle equals to 0º.b) With DVR, if Vs=VL=1pu with angle equals to 0º, find the voltage Vtand the DVR voltage injected (Vf).

in a balanced, 3 phase, positive sequence, grounded neutral source, supplies power to a balanced DELTA connected load. with the following conditions:  Ibc = 9.0 cis 237 degrees amps; and true power per phase is = 343 watts, with 0.55 power factor lagging What is the value of the reactance per phase of the delta load in ohms? (Place negative sign for capacitive reactance.)   ANSWER QUICKLY

In a balanced 3-phase system, the effective value of the IbB current for a triangular connected load is known as 15 (-150 degrees) Amperes and the effective value of the VCA voltage is known as 60 (90 degrees) Volts. Since it is known that the phase sequence is positive; Phase current IAB= 8.660 (60 degrees) A Phase current IAC= [Select ] Load impedance Z= [Select ] the total average power sent to the 3 phase load is Pt Aggregate= [Select ] (Note: Perform your operations using at least 3 digits after the comma.)