Ask Question, Ask an Expert

+1-415-315-9853

info@mywordsolution.com

Ask Electrical & Electronics Expert

problem 1: Describe the construction of different kinds of power transformer?

describe with the help of diagrams the given in relation to the construction of power transformers. Include the merits and demerits in your explanation.

a) Core type.
b) Shell type.
c) Sandwich wound.
d) Concentric wound.

problem 2: Recognize the operating principles of a power transformer under no-load and load conditions: A 230/1000V 50 Hz, single phase transformer has the given test data:

Open circuit test (L.V.)
Primary voltage = 230V
Primary current = 1.30 A
Input power = 115W
Short circuit test (H.V.)
Primary voltage = 50 V
Secondary current = 5.55A
Input power = 165 W

a) Find out and sketch the equivalent circuit for the transformer?

b) Find out the efficiency of the transformer at full load current at a power factor of unity and 0.8 lagging?

c) Find out the percentage regulation at a power factor of unity and 0.8 lagging?

problem 3: Discuss the modes of connection for polyphase transformers?

Discuss with help of electrical grouping and wiring connection diagrams the various kinds of connections for polyphase transformers listed below:

a) Dd 6
b) Dz 0
c) Yd 1
d) Yz 11

problem 4: Discuss the factors governing the tariff structures?

Describe three various industrial tariff structures; include details of the type of business which would suit each tariff structure.

problem 5: Analyze the methods for reducing energy consumption? Find out the cost of energy used in a system?

The energy consumption for a small factory is given at the end of the brief.

a) Three commercial tariffs from an energy supplier are shown below. Using these (or other commercially available tariffs), determine the most suitable tariff for the factory detailed. Your answer must be supported by mathematical analysis.

Tariff A:
Standing charge per quarter of £21.95 and every unit is charged at 19.93 ppu
Maximum demand is charged at £6.95 per KVA per annum

Tariff B:
All units are charged at 25.70 ppu
Maximum demand is charged at £5.95 per KVA per annum

Tariff C:
First 1500 units in a quarter is charged at 21.82 ppu
All additional units in the quarter charged at 18.49 ppu
Maximum demand is charged at £7.45 per KVA per annum

b) Propose changes to the working practices of the factory detailed in order to reduce the energy consumption and the cost of the energy bill.

Additional Information:

Factory Details:

The factory is fed and metered at 400/230V three-phase and neutral. It comprises of a main factory area, a storage warehouse for incoming raw materials and final products awaiting delivery and a small office block. The major intake position is located at one end of the factory and sub-main feeds are taken to the warehouse and office block.

The factory is on one level with big open doors at one end where goods and materials are moved to and from the warehouse. This is constructed of brick walls with a high single pitched roof and few windows.

The warehouse is a tall building of similar construction to the factory with two roller shutter doors, one for deliveries of raw materials and one for distribution of the finished product.

The office block is a brick building with a flat timber and felt roof. This has recently been refurbished. New double glazed windows were fitted and the electrical supplies and the lighting scheme were brought up to modern standards.

Electrical Loads:

1 x three-phase 45kW electrode boiler for heating a large volume of water to a temperature of 95oC for product washing; the water is then flushed down to the sewerage system

1 x three-phase 22kW processing unit operating with a total power factor of 0.71 lagging.

7 x three-phase 9kW pump motors operating at 0.82 power factor lagging.

12 x single-phase 2.25kW motors, various uses, operating at 0.78 power factor lagging.

16 x single-phase 3kW wall mounted forced convector heaters operating at 0.92 power factor lagging.

9kW of fluorescent discharge lighting operating at 0.76 power factor lagging employing magnetic choke switch start circuits fitted with standard discharge tubes.

Warehouse:

5kW of high bay high pressure mercury vapor lighting operating at 0.75 power factor lagging.

7 x 3kW block storage heaters.

Office:

8kW of single-phase power feeding computer equipment and vending machines.
3 x 2.25kW storage heaters
2.5kW of high frequency electronic ballast fluorescent lighting operating at 0.97 power factor lagging.

Energy Consumption Profile:

The three graphs shown point out the load pattern for the whole factory complex. The load profile for Monday to Friday and Saturday and Sunday can be supposed to be reasonably constant all through the year. Seasonal changes can be recognized by using the third graph as this shows the loading based on a weekly maximum demand.

498_load profile_1.jpg

1435_load profile_2.jpg

This can be taken that the initial cost of static, loss-free capacitors, comprising that of the essential control gear is £65.00 per kVAr. The annual interest and depreciation charges total 12% per annum.

The total number of units consumed throughout the 12 month period 2011 was 384,125.

Electrical & Electronics, Engineering

  • Category:- Electrical & Electronics
  • Reference No.:- M9450

Have any Question? 


Related Questions in Electrical & Electronics

Given the message aacccbccddab in which the probabilities

Given the message "AACCCBCCDDAB", in which the probabilities of symbols are P(A) = 0.50, P(B) = 0.25, P(C) = 0.125, and P(D) = 0.125, a. encode the data using Huffman coding. b. find the compression ratio if each origina ...

1 state faradays law in differential form for the general

1. State Faraday's law in differential form for the general case of an arbitrary electric field. How is it derived from its integral form? 2. What is meant by the net right-lateral differential of the x- and y-components ...

1 can h323 also be used for video2 given the following

1. Can H.323 also be used for video? 2. Given the following message, find the compressed data using run-length coding. AAACCCCCCBCCCCDDDDDAAAABBB 3. Given the following message, find the compressed data using the second ...

Consider a bar element as shown in the figure the

Consider a bar element as shown in the figure. The cross-sectional areas are A 1  and A 2  at nodes 1 and 2, respectively, and vary linearly. In addition, the gravitational acceleration is applied along the axial directi ...

Problem 1 - a consider an isolated generating station with

Problem 1 - a. Consider an isolated generating station with a local load and with: Governor time constant and gain T G = 0, K G = 1, Turbine time constant and gain T T = 1, K T = 1 System time constant T P = 20 Total dam ...

The mass m of drops formed by liquid discharging by gravity

The mass M of drops formed by liquid discharging by gravity from a vertical tube is a function of the tube diameter D, liquid density, surface tension, and the acceleration of gravity. Determine the independent dimension ...

A continuous belt passes upward through a chemical bath at

A continuous belt passes upward through a chemical bath at velocity v 0  and picks up a film of liquid of thickness h, density, ρ, and viscosity μ. Gravity tends to make the liquid drain down, but the movement of the bel ...

1 outline the steps involved in the magnetoquasistatic

1. Outline the steps involved in the magnetoquasistatic field analysis of a parallel plate structure and the determination of its input behavior. Compare the input behavior with the magnetostatic case. 2. Outline the ste ...

1 complete the missing steps in the evaluation of the

1. Complete the missing steps in the evaluation of the integral in equation (9.39a). 2. Find the time-average power required to be radiated by a half-wave dipole in order to produce an electric field intensity of peak am ...

1 in which situation a unicast session or a multicast

1. In which situation, a unicast session or a multicast session, can feedback received from an RTCP packet about the session be handled more easily by the sender? 2. Can the combination of RTP/RTCP and SIP operate in a w ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

Section onea in an atwood machine suppose two objects of

SECTION ONE (a) In an Atwood Machine, suppose two objects of unequal mass are hung vertically over a frictionless

Part 1you work in hr for a company that operates a factory

Part 1: You work in HR for a company that operates a factory manufacturing fiberglass. There are several hundred empl

Details on advanced accounting paperthis paper is intended

DETAILS ON ADVANCED ACCOUNTING PAPER This paper is intended for students to apply the theoretical knowledge around ac

Create a provider database and related reports and queries

Create a provider database and related reports and queries to capture contact information for potential PC component pro

Describe what you learned about the impact of economic

Describe what you learned about the impact of economic, social, and demographic trends affecting the US labor environmen