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A three-phase transformer is rated
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Power System Analysis and Design (MindTap Course List)
- A substation transformer is serving the following loads: Classification Total Load Demand Factor Lighting 300 kW 60% Power 1200 kW 80% Heating 500 kW 90% If the diversity factor among the load types is 1.5, determine the demand factor of the transformer. Subject: DISTRIBUTION SYSTEMarrow_forwardA network is composed of the utility having Ssc=250MVA, and an 2000KVA transformer, rated at 20KV/400V (no load), whose voltage impedance is 7%, and whose load losses are 15750watts. the short circuit at the secondary of the transformer using the impedance method is: a)27.01KA b)None of these c)25.8KA d)30KAarrow_forwardA 5,000-kVA, 3-phase transformer, 13.2/33-kV, A/Y, has a copper loss of 11 kW. The impedance drop at full-load is 7.5%. Calculate the primary voltage when a load of 4000 kW at 0.8 p.f. is delivered at 33 kv.arrow_forward
- An Electrical engineer is asked by a client to prepare a technical specification on specific items connected with a project. Hence, the engineer is requested to prepare the technical specification of the following: PROJECT: A Subdivision Development Lot AREA; 2 Hectares LOCATION: Brgy. Kanlurang Mayao, Lucna City Technical specification of fuse cutout Technical specification of transformerarrow_forward1) A 600 V source feeds a 480 V load with a transformer Conventional 5000 VA, 480/120 V. Consider the ideal transformer. a) Calculate the apparent nominal power of the transformer in the connection as Autotransformer. b) Calculate the currents on the high voltage side and on the low voltage side in these conditions. c) Calculate the current in the common coil in the connection as Autotransformer.arrow_forwardQuestion 4. The approximate equivalent circuit of a three-phase ∆ /∆ connected 60 Hz, 4000/1000 V transformer reduced to the primary and its parameters are as follows. It is given as Z'y=7.75+j8.85 Ω. A voltage of 4000 Volt is applied to the primary winding of this transformer. Accordingly, calculate the values of primary line current, secondary line current, secondary line voltage and total input and output power for the three phases. 1-) If 4000 Volt voltage is applied to the primary of the transformer above, enter the amplitude value of the primary line current in the box below. ( Phase value will not be entered, for example, if the amplitude is 150 Volts phase is 36.86 degrees, only 150 will be entered!!! 2 digits after the comma will be enough. ) 2-) If 4000 Volt is applied to the primary of the transformer above, enter the amplitude value of the secondary line current in the box below. ( Phase value will not be entered, for example, if the amplitude is 150 Volts phase is 36.86…arrow_forward
- Power transformer A, has Rated power of 150MVA. Line voltage of 330/66 kV Frequency=50Hz Connection Yd1 Z impedance=8% X/R =7.94 To accommodate a higher load a new transformer B,rated 180 MVA, 330/66 kV, 50 Hz,is to be installed in parallel with the existing transformer. Determine the load on each transformer if the total load is 300 MVA at a power factor of 0.9 laggingarrow_forwardA single-phase 100-kVA, 2,400/240 V, 60-Hz distribution transformer is used as a step-down transformer. The load, which is connected to the 240 V secondary winding, absorbs 80 kVA at 0.8 power factor lagging and is at 230 V. Assuming an ideal transformer, calculate the following:(a) primary voltage;(b) load impedance;(c) load impedance referred to the primary;(d) the active and reactive power supplied to the primary winding.arrow_forwardA Transformer with 10:1 ratio and rated at 50-kVA, 2400/240-V, 50-Hz is used to step down the voltage of a distribution system. The low-tension voltage is to be kept constant, if the transformer has: R = 2.2 0, R2 = 0.014 Q, X, = 4.1 0, X2 = 0.03 0, then, a. What load impedance connected to low-tension side will be loading the transformer fully. b. Calculate the equivalent resistance as referred to primary. c. Calculate the equivalent reactance as referred to primary. d. Calculate the equivalent impedance as referred to primary. e. Calculate the total Cu loss.arrow_forward
- 5) A short circuit test on 15kVa, 2400/240V, 60Hz transformer yields the following results: 6.25A, 132V and 215W. (A) determine the equivalent resistance referred to the high side in ohms, (b) determine the equivalent reactance referred to the high side in ohms,(c) determine the equivalent impedance referred to the high side in ohms, (d) determine the percent impedance of the transformer. Subject Electrical Apparatus and Devicesarrow_forwardA 20-kVA 8000/277-V distribution transformer has the following resistances and reactance: RP = 32 Ω RS = 0.05Ω X P = 45Ω XS = 0.06Ω RC = 250 kΩ X M = 30 kΩ The excitation branch impedances are given referred to the high-voltage side of the transformer. (a) Find the equivalent circuit of this transformer referred to the high-voltage side. (b) Find the per-unit equivalent circuit of this transformer. (c) Assume that this transformer is supplying rated load at 277 V and 0.8 PF lagging. What is this transformer’s input voltage? What is its voltage regulation? (d) What is the transformer’s efficiency under the conditions of part (c)?arrow_forwardA transformer having a nameplate rating of 30kVA, 4160/230V, single phase, 60hz with an equivalent impedance of 8 ohms referred to HV side. If the X/R ratio of the transformer is 10, determine the reading of the voltmeter during short circuit test with its low side is short circuited while the instruments are on the high side. Assume full load current applied during the test.arrow_forward
- Power System Analysis and Design (MindTap Course ...Electrical EngineeringISBN:9781305632134Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. SarmaPublisher:Cengage Learning