Part B (20 marks) Figure 2 shows a three phase 22kV, 50Hz radial system, which is to be protected by two inverse- time...
can you calculating this question and explain why? thanks A distribution network shown in Figure 3 consists of a 40-MVA and 33/22-kV step-down transformer with a reactance of 10% and two distribution lines each having a reactance of 5 Q2. The load connected to each bus is also shown in the figure. The CO-8 overcurrent relays are used to protect the system. The time-current curve of the CO-8 relay is shown in Figure 4 on page 5. Assume that the...
select one Best match 11) A 12 kV radial system is given below, Assuming using relay CO-7, 3 cycles breaker operation time and 0.5 second coordination time delay, what are the best settings to protect the system shown below: (10 points) 12 kV Typical time curves ype Co-7 C.T.R-400/5 C.T.R-200/5 Current tap settings: 4.5,6,78,10,12 amperes 4 MVA Isc-1.6 kA 4 MVA Isc-1.2 kA Time dial TS1 TDS1 TS2 TDS2 A) 51/252 B) 41/24 C) 51/25 D) 41/24 2 4 5...
18. The primary conductor in Figure 10.2 is one phase of a three-phase trans- mission line operating at 345 kV, 700 MVA, 0.95 power factor lagging. The CT ratio is 1200:5, and the VT ratio is 3000:1. Determine the CT second- ary current and the VT secondary voltage V. Assume zero CT error. A CO-8 relay with a current tap setting of 5 amperes is used with the 100:5 CT in Example 10.1. The CT secondary current I' is the...
For the radial distribution system shown in the figure below, the impedances of the two line sections and the equivalent generator are given in pu. Consider symmetrical faults only (three-phase, positive sequence) and assume that the relay at bus A is set to pickup for a fault at bus C. The relay at bus B is set to pickup at one half of that value. 2) Assume there is a DER installed at bus C whose fault current contribution is...
2. A three-phase short circuit occurs at the bus 1 for the system shown in figure below. Neglecting prefault currents and assuming that the generator is operating at its rated voltage, determine the subtransient fault current using superposition. bus 1 bus 2 j6522 ww m AY 25 MVA 13.8 kV 15% 25 MVA 13.2/69 KV 11% 25 MVA 69/13.2 kV 11% 15 MVA 13 kV 15%
Problem 7. Three-phase Balanced Fault Analysis. For the two-generator system below, a three-phase short occurs at point A. Ignoring prefault currents and assuming a prefault bus voltage of 1.0 р.u., determine the fault current, in kA, contributed from generator G Assume base values of 50 MVA and 50 kV on transmission line side. 25 kV 50 MVA, 2.5% 1:2 50 MVA, 2090 25 kV 75.MVA, 15% г,-0.4% Figure 1 Problem 7. Three-phase Balanced Fault Analysis. For the two-generator system below,...
5- What is meant by each of the PSM, Slu nuip Question 2-(5 Marks TSMS For the given redial system, calculate the-Ru Required CTs ratio of the system to achieve the relay coordination and the time multiplier E Thre-phase io ZgBe Bus B Bus C CT ns setting of each relay. Rp is to protect section ,ey aby層 BC while RA is its back-up and primary protect section AB. Draw the variation oftheI maximum fault current against the fault locations....
Qustion 2.120 marks) a) Figure I below shows a system with plant-I and plant-2 connected to bus-1 and bus-2 respectively. There are two loads and 3 branches. The bus-I is the reference bus with 1.040° pu voltage. Base MVA is 100 If the branch currents and branch impedance values are as follows -2.5-j0.50pu -2-j040 pu I 1.5-j0.3 pu Calculate: 7-0.05+j0.20 pu -0.02+j0.08 pu Z 0.025+j0.10 pu i. Current distribution factors (4 marks) ii. Power factor angles at bus 1 and...
b) The figure below shows an FM demodulator. s'(t)Envelope detector Demodulated signal s(t) Differentiator Figure 4: Question 2(b) In the system above, the differentiator performs the time-differentiation operation s'(t) = as(t). Also, the envelope detector is assumed to be ideal, capable of extracting the envelope of the incoming signal perfectly. Describe, by equations, how the above FM demodulator may exactly recover the message signal from the FM signal. (6%) (c) Is the FM demodulator in Question 2(b) a coherent detector,...