O ElecTech DCmc... -> Third Year 2020-2021 Medical Instr. Tech. Eng. Dept Subject: ElecTech DC M/C Collection Dr. Harith Collection of exercises on d.c. machines From (d.c. machines, Ranson & Webb) Exercise 1: 4/iv If a 4-pole d.c. generator supplies a total current of 50A, what will be the current per conductor in the case of (i) a lap winding, (ii) a wave winding. ...
Load flow analysis
Load flow analysis is a study or numerical calculation of the power flow of power in steady-state conditions in any electrical system. It is used to determine the flow of power (real and reactive), voltage, or current in a system under any load conditions.
Nodal Matrix
The nodal matrix or simply known as admittance matrix, generally in engineering term it is called Y Matrix or Y bus, since it involve matrices so it is also referred as a n into n order matrix that represents a power system with n number of buses. It shows the buses' nodal admittance in a power system. The Y matrix is rather sparse in actual systems with thousands of buses. In the power system the transmission cables connect each bus to only a few other buses. Also the important data that one needs for have a power flow study is the Y Matrix.
Types of Buses
A bus is a type of system of communication that transfers data between the components inside a computer or between two or more computers. With multiple hardware connections, the earlier buses were parallel electrical wires but the term "bus" is now used for any type of physical arrangement which provides the same type of logical functions similar to the parallel electrical bus. Both parallel and bit connections are used by modern buses. They can be wired either electrical parallel or daisy chain topology or are connected by hubs which are switched same as in the case of Universal Serial Bus or USB.
![1%9A |I1.
O ElecTech DCmc...
->
Third Year 2020-2021
Medical Instr. Tech. Eng. Dept
Subject: ElecTech
DC M/C Collection
Dr. Harith
Collection of exercises on d.c. machines
From (d.c. machines, Ranson & Webb)
Exercise 1: 4/iv
If a 4-pole d..c. generator supplies a total current of 50A, what will be the current per conductor in the
case of (i) a lap winding, (ii) a wave winding.
Exercise 2: 5/iv
A 50 kW, 200V, 6-pole generator has a lap connected armature of 450 conductors. Determine the e.m.f
generated and the current flowing in each conductor. Also determine the corresponding values for
wave connection.
Exercise 3: 1/vii
Calculate the flux in a 4-pole generator with 722 armature conductors generating 500 V when running
at 1000 r.p.m, if the armature is (i) lap connected,(ii) wave connected.
Exercise 4: 3/vii
Calculate the e.m.f of a bi-polar machine with 1000 armature conductors when running at 1200 r.p.m,
if the flux is 0.02 Wb.
Exercise 5: 4/vii
A 4-pole machine has an armature with 60 slots and 10 conductors per slot and revolves at 1500 r.p.m,
the flux per pole being 0.05Wb. Calculate the e.m.f generated if the winding is lap connected.
Exercise 6: 5/vii
A 4-pole machine running at 1500 r.p.m has an armature with 90 slots and 6 conductors per slot. The
flux per pole being 0.06 Wb. Determine the terminal e.m.f as a d.c. generator if the coils are lap
connected. If the current per conductor is 100 A, determine the electrical power.
Exercise 7: 3/x
A 400 V series motor has a total resistance of 0.5 ohm. It takes 3A on no load. What is the value of
no-load back e.m.f? If on full load the back e.m.f falls to 350V, calculate the full load current.
Exercise 8: 1/xi
A 250 V shunt motor has an armature resistance of 0.5 ohm and runs at 1200 r.p.m, when the armature
current is 80A. If the torque remains unchanged find the speed and the armature current if the field is
strengthened by 25 percent.
Exercise 9: 2/xi
A 4-pole series machine with wave connected armature of 786 conductors has a flux per pole of 0.025
Wb when taking a current of 25A. calculate the torque developed in N.m.
Exercise 10: 4/xi
i) Sketch and explain the shape of the torque-current and speed-current curves of a series motor.
ii) a 500V series motor has a resistance of 0.2 ohm and runs at 400 r.p.m when taking current of 60A.
Calculate the speed when taking 30A if the flux is 35% less than the 60A case.
File: X:ElecTech DCmc Collection Quesstions.doc](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F679fb8a9-a657-4aa9-888b-9b483a2bc236%2Fb93fdd59-6f87-40f9-91f2-a1f3157269b8%2Fqchv0ly_processed.jpeg&w=3840&q=75)
![](/static/compass_v2/shared-icons/check-mark.png)
Step by step
Solved in 2 steps with 1 images
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
![Power System Analysis and Design (MindTap Course …](https://www.bartleby.com/isbn_cover_images/9781305632134/9781305632134_smallCoverImage.gif)
![Power System Analysis and Design (MindTap Course …](https://www.bartleby.com/isbn_cover_images/9781305632134/9781305632134_smallCoverImage.gif)