Answered: calculate the efficiency at half load

Engineering

Electrical Engineering

calculate the efficiency at half load

Power System Analysis and Design (MindTap Course List)

6th Edition

ISBN:9781305632134

Author:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Publisher:J. Duncan Glover, Thomas Overbye, Mulukutla S. Sarma

Chapter3: Power Transformers

Section: Chapter Questions

Problem 3.11P: For the transformer in Problem 3.10. The open-circuit test with 11.5 kV applied results in a power...

See similar textbooks

Related questions

Q: A Step-down transformer at Van Eck power station in Windhoek operates at V=10 kV on the primary side…

A: we need to find out the current, on secondary side of the transformer.

Q: 7- The Full load. Cu loss and iron loss of a transformer are 920 W and 430 W respectively. (i)…

A: In this question we need to find loading of the transformer at which maximum efficiency occurs and…

Q: 8. The two winding transformer and the autotransformer of the circuit shown in Figure are ideal.…

A: In a transformer MMF remains same i.e, I1N1=I2N2 amd in auto transformer total current is the…

Q: The primary and secondary windings of a 500 kVA transformer have resistances of 0.44 Ω and 0.0027 Ω,…

A: The solution is given below

Q: You are given five light bulbs designed to operate on 160 mA current at 3.0 V (rms values), arid…

A: a) The circuit diagram consisting of the AC power source, transformer, and five resistors connected…

Q: A building has a 35 kW transformer that is connected all the time. A local electrical contractor…

A: Given P = 35 Kw Core loss = 4% Electrical costs = 9 ζ/Kwh Average building use = 8 h/month Total…

Q: 300kVA transformer has primary and secondary winding resistances of 0.5Ω, and 0.0015Ω respectively.…

A: First we will find total total secondary resistance and than copper losses at 40%load. Cupper losses…

Q: A 20-ohm resistance is connected across the secondary winding of a single-phase power transformer…

A: Given:-Secondary voltage,V2=150vResistance is connected across secondary winding,∴R2=20ΩSupply…

Q: The temperature rise of a transformer is 25°C after one hour and 37.5° after two hours of starting…

Q: A 480/2400-V rms step-up ideal transformer delivers 46 kW to a load with a load/secondary current of…

A: Disclaimer: Since you have asked multiple questions, we will solve the first question for you. If…

Q: Find the efficiency of a 150 kVA transformer at 25 % full load at 0.8 p.f. lag if the copper loss at…

Q: A 15.5-kVA, 2200/210-V transformer has circuit parameters referred to the primary side given in…

A: TRANSFORMER: The transformer transfers power from one circuit to another circuit without a change…

Q: 29: For the ide al transformer circuit shown, find th average power delivered to (1Q) resistor?…

Q: Compute the copper losses at full load if a 500KVA transformer has 90% efficiency at both half-load…

Q: The failure of power transformers is assumed to follow a Poisson probability distribution. Suppose…

A: As per the guidelines, the first question has been solved in the following section.

Q: A 1000-VA 380 / 110 V conventional transformer is to be used to supply power from a 490-V source to…

A: From the given data of normal transformer, KVA=1000 VAVP=380 VVS=110 V To the Auto-transformer…

Q: Find the power absorbed by the 10-0 resistor in the ideal transformer circuit given in the figure.…

A: The solution is given below

Q: The Full load. Cu loss and iron loss of a transformer are 920 W and 430 W respectively. (i)…

Q: A 40-kVA, 8000/230-V distribution transformer has an impedance referred to the primary of 18 + j80…

A: In this question we need to find a secondary voltage of the transformer.

Q: 1- A 200-kVA transformer has an efficiency of 98 % at full-load. If the maximum efficiency occurs at…

Q: The rating of current transformer is given as 200/5A 5P10 20VA. Assume that the secondary resistance…

A: Given CT secondary resistance =Rc t =0.12 Ω from CT data 200/5A 5P10 20VA Sn =20 VA I=5 A Fn=10

Q: In an ideal transformer, the power in the secondary coil is 10 kW. The voltage of the primary is 500…

A: The given information for an ideal transformer is Power in secondary coil P2=10 kW. Voltage of…

Q: 11. A 440/110 V transformer has a primary resistance of 0.03 ohm and secondary resistance of 0.02…

Q: To a distribution transformer 8 residential consumers are connected. Each house connected load is 10…

A: Since in the given question, there is no mention of the demands or average demand or load factor, we…

Q: A 200-KVA transformer has an efficiency of 98 % at full-load. If the maximum efficiency occurs at…

Q: Estimate its efficiency when delivering its full load output at p.t. of 0.8 lagging,

A: Given, Rating of single phase transformer is 10 kVA Maximum efficiency of transformer is 94%, when…

Q: 5- Find the efficiency of a 150KVA transformer at 25%, 33% and 100% full load at: a/ unity power…

Q: 10- A 10-KVA, 500/250-V, single-phase transformer has its maximum efficiency of 94 % when delivering…

Q: A 15-kVA 8000/230-V distribution transformer has an impedance referred to the prima of 80+ j3000.…

A: a. The turns ratio of the transformer is determined as a=8000230=34.78 The load impedance referred…

Q: A small plant produces electric energy and, through a transformer, sends it out over the…

A: Given that I = 50 AV = 20 kV. R = 1.2 ohms/km L= 25 kmRline=1.2×25=30 ohm (a) Power loss in the…

Q: Transformers: Consider an ideal step-down transformer that converts 120 VAC (wall-socket voltage) to…

A: Since you have posted a question with multiple sub-parts, we will solve first three sub-parts for…

Q: 2- Find the efficiency of a 150 kVA transformer at 25 % full load at 0.8 p.f. lag if the copper loss…

Q: 120Vm 100 F Express the numerical values up to 2 decimal places. Vr[pp) = Vpp Vdc = V 20000

A: Solution ; F= 60hz T = 1f = 0.0167 sec Ripple voltage for bridge Rectifier Vr = Vp.TpRLC Tp = Time…

Q: A Step-Down Transformer. A transformer connected to a 120 V (rms) ac line is to supply 12.0 V (rms)…

A: Since you have posted a question with multiple sub-parts, we will solve the first three sub-parts…

Q: A transformer rated at 1000 kVA is operating near capacity as it supplies a load that draws 900 kVA…

A: According to the question, we have to find, real power delivered to the load and how mu ch…

Q: Q.29: For the ideal transformer circuit shown, find the average power delivered to (1Q) resistor?…

A: First we will apply KCL at node (intersection of 4 ohm and 1 ohm resistor) and than we will find…

Q: Problem: Determine the peak-to-peak ripple and dc output voltages. The transformer has a 36 V rms…

A: The given circuit is a bridge rectifier and the required parameters can be calculated by using the…

Q: 2- Find the efficiency of a 150 kVA transformer at 25 % full load at 0.8 p.f. lag if the copper loss…

A: Given, kVA rating, S = 150 kVA Factor of load, x = 25 % = 0.25 Power factor, cosϕ=0.8 Copper loss,…

Q: A 150 kVA transformer has an efficiency of 98% at full load unity p.f. At full load, copper losses…

Q: Find the power absorbed by the 10-Q resistor in the ideal transformer circuit given in the figure.…

A: This question belongs to electrical circuit theory . It is based on the concept of kirchhoff's…

Q: Provide an analysis for the transformer mentioned below. The followings are the reading from the…

A: Note: We are authorized to answer three subparts at a time, since you have not mentioned which part…

Q: 3. A 500/250 V, 1-phase transformer has constant losses of 150 W. When delivering an output of 8 kW…

A: In this question we need to find a variable loss of the transformer for given loading conditions. In…

Q: TRUE or FALSE: If a transformer operates at maximum efficiency, then the power factor is at unity

A: condition for maximum efficiency is copper losses are made equal to iron losses . and maximum…

Q: Determine the efficiency of a 150 kVA transformer at 50% of full load and 0.8 power factor lagging…

Q: A neon sign requires a current of 106 mAo-p at 12900 Vo-p. This means it needs Arms at Vrms- Assume…

A: Given the rating of a neon sign is Current=106 mA0-p and voltage 12900 V0-p.

Q: Q.29: For the ideal transformer circuit shown, find the 452 average power delivered to (1Q)…

A: for the ideal transformer circuit shown find the average power delivered to 1ohm resistor

Q: A Buck converter has an output power of 1950 Watts, and a source voltage of 1000V (the constant DC…

A: For a buck converter Vo=DVs.

Q: A 10-KVA, 500/250-V, single-phase transformer has its maximum efficiency of 94 % when delivering 90…

Q: Q.29: For the ideal transformer circuit shown, find the 452 average power delivered to (1Q)…

Q: carrying? Ans. 10 45 percent 10.44 A 100-KVA transformer is at 80 percent of rated load at power…

Concept explainers

Maximum power transfer theorem

A resistive load will consume maximum power from a network when the load resistance is equal to the resistance of the network as viewed from the open-circuit terminals, with all energy sources removed leaving only the internal resistances. Physicist Moritz von Jacobi introduced the maximum power transfer theorem in 1940. Therefore, this theorem is also known as Jacobi's law.

Question

A 200 KVA transformer has an efficiency of 98% at full load. If the maximum efficiency
occurs at three quarters of full load, calculate the efficiency at half load. Assume p.f. of 0.8 at
all loads. [ Ans: 97.9%]

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

SEE SOLUTION Check out a sample Q&A here

Step 1

VIEW

Step 2

VIEW

Step by step

Solved in 2 steps with 2 images

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, electrical-engineering and related others by exploring similar questions and additional content below.

Similar questions

A two-winding single-phase transformer rated 60kVA,240/1200V,60Hz, has an efficiency of 0.96 when operated at rated load, 0.8 power factor lagging. This transformer is to be utilized as a 1440/1200-V step-down autotransformer in a power distribution system. (a) Find the permissible kVA rating of the autotransformer if the winding currents and voltages are not to exceed the ratings as a two-winding transformer. Assume an ideal transformer. (b) Determine the efficiency of the autotransformer with the kVA loading of part (a) and 0.8 power factor leading.
The transformer of Problem 3.16 is supplying a rated load of 50 kVA at a rated secondary voltage of 240 V and at 0.8 posr factor lagging. Neglect the transformer exciting current. (a) Determine the input terminal voltage of the transformer on the high-voltage side. (b) Sketch the corresponding phasor diagram. (c) If the transformer is used as a step-down transformer at the load end of a feeder whose impedance is 0.5+j2.0, find the voltage VS and the power factor at the sending end of the feeder.
A single-phase 100-kVA,2400/240-volt,60-Hz distribution transformer is used as a step-down transformer. The load, which is connected to the 240-volt secondary winding, absorbs 60 kVA at 0.8 power factor lagging and is at 230 volts. Assuming an ideal transformer, calculate the following: (a) primary voltage, (b) load impedance, (c) load impedance referred to the primary, and (d) the real and reactive power supplied to the primary winding.
For the transformer in Problem 3.10. The open-circuit test with 11.5 kV applied results in a power input of 65 kW and a current of 30 A. Compute the values for GcandBm in siemens referred to the high-voltage winding. Compute the efficiency of the transformer for a load of 10 MW at 0.8 p.f. lagging at rated voltage.
Consider an ideal transformer with N1=3000andN2=1000 turns. Let winding 1 be connected to a source whose voltage is e1(t)=100(1| t |)volts for 1t1ande1(t)=0 for | t |1 second. A2- farad capacitor is connected across winding 2. Sketch e1(t),e2(t),i1(t),andi2(t) versus time t.
Consider two interconnected voltage sources connected by a line of impedance Z=jX, as shown in Figure 2.27. (a) Obtain expressions for P12 and Q12. (b) Determine the maximum power transfer and the condition for it to
An ideal transformer has no real or reactive power loss. (a) True (b) False
Consider Figure 3.25 of the text for a transformer with off-nominal turns ratio. (i) The per-unit equivalent circuit shown in part (c) contains an ideal transformer which cannot be accommodated by some computer programs. (a) True (b) False (ii) In the - circuit representation for real c in part (d), the admittance parameters Y11 and Y12 would be unequal. (a) True (b) False (iii) For complex c, can the admittance parameters be synthesized with a passive RLC circuit? (a) Yes (b) No
A 23/230-kV step-up transformer feeds a three-phase transmission line, which in turn supplies a 150-MVA,0.8 lagging power factor load through a step-down 230/23-kV transformer. The impedance of the line and transformers at 230kVis18+j60. Determine the tap setting for each transformer to maintain the voltage at the load at 23 kV.
A Step-Down Transformer. A transformer connected to a 120 V (rms) ac line is to supply 12.0 V (rms) to a portable electronic device. The load resistance in the secondary is 5.00 Ω. (a) What should the ratio of primary to secondary turns of the transformer be? (b) What rms current must the secondary supply? (c) What average power is delivered to the load? (d) What resistance connected directly across the 120 V line would draw the same power as the transformer? Show that this is equal to 5.00 Ω times the square of the ratio of primary to secondary turns.
A 400-turns auto transformer, operating in the step-down mode with 25 percent tap supplies a 4.8 kVA, 0.85 lagging power factor load. The input to the transformer is 2400 V, 60 Hz. Neglect the small losses and leakage effects. What will be the apparent power(in kVA) conducted and transformed respectively?
A Step-down transformer at Van Eck power station in Windhoek operates at V=10 kV on the primary side during wintertime. The voltage drawn from the secondary side of the transformer is V = 118 Volts. What is the current in Amps, on the secondary side of the transformer if the average rate of energy consumption demand is at 112.3 kW?