Project Description on DC-Machines about 3D-Animations regarding the principles and application PDF

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DC-Machines about 3D-Animations provides you the Project Description regarding the application-driven on DC machine principles and the laws....

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CAMARINES NORTE STATE COLLEGE COLLEGE OF ENGINEERING ELECTRICAL ENGINEERING DEPARTMENT BACHELOR OF SCIENCE IN ELECTRICAL ENGINEERING

Name: Course & Block: Code – Subject: Activity no.:

Instruction:

Jericho F. Quiñones BSEE-3B EE 104 - Electrical Machines 1 Project: -DC Machine 3D Animation

Rating: Date of Submission:

1. The class will be divided into 5 group, students will identify their group members. 2. Each group will conduct their virtual/online meeting via Google Meet or Zoom or other platform convenient with the students to discuss the following:  Content of their output  Division of labor  Software to be use 3. Groups will submit their outputs through LMS as follows:  3D illustration  Report Paper (consist of but not limited to: Introduction, Discussion, Individual Conclusion, References, Photo Documentation of Conducted Meeting(s)) 4. The rubric assessment shall be attached at the last page of the report. 3D illustration of DC Machine

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CAMARINES NORTE STATE COLLEGE COLLEGE OF ENGINEERING ELECTRICAL ENGINEERING DEPARTMENT BACHELOR OF SCIENCE IN ELECTRICAL ENGINEERING

INTRODUCTION In the book Electrical Machines and Drive by Jan A, Melkebeek, it is stated there that DC commutator machines (abbreviated as ‘DC machines’) are (some of) the oldest electrical machines. Thanks to the simplicity of direct current, DC machines were able to maintain a leading position for many years, even after the introduction of AC and induction and synchronous machines in the beginning of the 20th century. Later on, this position was threatened by the advantage of AC as to lossless transforming voltage and current levels, at least for generators and constant speed drives. For variable speed drives, however, DC machines were still the preferred drives for variable speed drives (i.e. controlled drives). This changed completely with the introduction of power electronics in the second half of the 20th century, which facilitated controlled drives using induction and synchronous machines. Nevertheless, DC machines are still used for low power applications (automotive). However, this may not last as they are less reliable and generate higher maintenance costs compared to pm-synchronous machines with low-cost power-electronic supplies. Electromechanical Energy Conversion An electrical machine is a device that can convert either mechanical energy to electric energy or electrical energy to mechanical energy. When such a device is used to convert mechanical energy to electrical energy, it is called generator. When it converts electrical energy to mechanical energy, it is called motor. Since any given electrical machine can covert power in either direction, any machine can be used as either a generator or motor. The transformer is an electrical device that is closely related to electrical machines. It converts ac electrical energy at one voltage level to AC electrical energy at another voltage level. Since transformers operate on the same principles as generators and motors, depending on the action of a magnetic field to accomplish the change in voltage level, they are usually studied together with generators and motors. The electromechanical energy conversion process takes place through the medium of the electric or magnetic field of the conversion device of which the structures depend on their respective functions. D.C. Generator Basic Principle of D.C. Generator In general, an electrical generator is a rotating machines\ which converts mechanical energy into electrical energy Electrical Generator works on the principle of electromagnetic induction. This explained as follow. According to Fraday’s Law of Electro- Magnetic Induction, when a conductor or a coil is rotated in a magnetic field in such a way, to cut the magnetic lines of flux, an e.m.f. is induced in a conductor in the coil. If the circuit of the conductor or coil is closed in proper way, a current flow through the circuit. The magnitude of induced e.m.f. is proportional to the speed of rotation of the conductor, the flux ii nth magnetic field and the number of conductor or coils connected in series. In d.c. generator the conductor of the coils are arranged on the cylindrical rotor called armature. The armature is the rotated in the magnetic field so as to cut the magnetic flux. To rotate this armature,, another rotating device called prime-mover is used. The prime movers used for this energy is driven by mechanical energy applied to shaft. Thus the mechanical energy is converted to electrical energy. In d.c. generator the magnetic field is stationary and the armature rotates. When the armature=r is rotated, the armature conductor cuts magnetics lines of flux, so dynamically induced e.m.f. is induced in armature. The e.m.f. thus induced in d.c. generator is alternating one and this is converted in to direct e.m.f. ny a device known as “ Commutator” . The commutator is mounted at the one end of the armature, on the same shaft of the armature. The direction of induced e.m.f. is determined by using fleming’s right hand rule. Page 2 of 8

CAMARINES NORTE STATE COLLEGE COLLEGE OF ENGINEERING ELECTRICAL ENGINEERING DEPARTMENT BACHELOR OF SCIENCE IN ELECTRICAL ENGINEERING

The Magnetic Field Magnetic fields are the fundamental mechanism by which energy is converted from one form to another in motors, generators, and transformers. Four basic principles describe how magnetic fields are used in these devices: 1. A current-carrying wire produces a magnetic field in the area around it. 2. A time-changing magnetic field induces a voltage in a coil of wire if it passes through that coil. (This is the basis of transformer action.) 3. A current-carrying wire in the presence of a magnetic field has a force induced on it. (This is the basis of motor action.) 4. A moving wire in the presence of a magnetic field has a voltage induced in it. (This is the basis of generator action.) Right-hand rule (a)

(b)

Figure 1.Block diagrams of electromechanical energy conversion devices

F= q(E+ v × B) Where: F : newtons, q : coulombs, E : volts/meter, B : telsas, v : meters/second Applications of DC Generators The applications of the various types of DC Generators are as follows:Separately Excited DC Generators Figure 2. (a&b) Determining the polarity of a magneto motive force source in a magnetic circuit  Separately excited DC Generators are used in laboratories for testing as they have a wide range of voltage output.  Used as a supply source of DC motors. Shunt wound Generators DC shunt-wound generators are used for lighting purposes. Used to charge the battery. Providing excitation to the alternators. Series Wound Generators      

DC series wound generators are used in DC locomotives for regenerative braking for providing field excitation current. Used as a booster in distribution networks. Over compounded cumulative generators are used in lighting and heavy power supply. Page 3 of 8

CAMARINES NORTE STATE COLLEGE COLLEGE OF ENGINEERING ELECTRICAL ENGINEERING DEPARTMENT BACHELOR OF SCIENCE IN ELECTRICAL ENGINEERING  

Flat compounded generators are used in offices, hotels, homes, schools, etc. Differentially compounded generators are mainly used for arc welding purpose.

D.C. Motor An electric motor is a machines which converts electrical energy into mechanical energy. It’s action is based on the principle that when a current carrying conductor is placed in a magnetic field, it experiences a mechanical force whose direction is given by “Fleming’s left-hand Rule.” Constructionally, there is no difference between a DC generator and DC Motor. In fact, the same DC machine can be used interchangeable as generator or as a motor. When a Generator is in operation, it is driven mechanically and develops a voltage. This voltage can send a current in a load resistance. When a motor is in operation, it develops torque. This torque can produce mechanical rotation. DC motors are also like generator classified into shunt wound series wound and compound wound motors. Fleming’s Right-Hand Rule The direction of motion of the conductor can be determined by flemmingg’s left hand rule knowing the direction of the magnetic field and the direction of the current in the conductor, the motion of the conductor determined. Keep the forefinger middle finger and thumb of the left hand mutually perpendicular to one another. If the forefinger indicates thedirection of the magnetic field and the middle finger indicate the direction of current in the conductor, then the thumb points the direction of motion of conductor.

Construction The most important electromagnetic parts of a DC machine are the following (see also Fig. 4) • The standstill excitation system mainly consisting of

 the main poles P  the excitation winding W (or permanent magnets for small machines)  the closing yoke Y

• The rotating armature A: the core of the armature is always laminated, with iron sheets of less than 0.5 mm. The armature has slots for the armature conductors. The armature winding is a closed winding and is connected to the commutator segments in several places. Brushes make Page 4 of 8

CAMARINES NORTE STATE COLLEGE COLLEGE OF ENGINEERING ELECTRICAL ENGINEERING DEPARTMENT BACHELOR OF SCIENCE IN ELECTRICAL ENGINEERING

contact with the segments to provide current to the armature. Figure 5 provides more details of the construction of a DC machine. Figure 5 Construction details of DC machine

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CAMARINES NORTE STATE COLLEGE COLLEGE OF ENGINEERING ELECTRICAL ENGINEERING DEPARTMENT BACHELOR OF SCIENCE IN ELECTRICAL ENGINEERING

1. armature core (segmented) conductors in slots 2. end coils of the armature winding 3. commutator (copper segments) 4. brush holders with brushes 5. (a,b) shaft ends 6. (a,b) bearings 7. Ventilator

with

8. housing (with yoke, segmented or massive) 9. main field pole (in most cases segmented) 10. main field coil 11. electrical terminals 12. (a,b) feet (supports) 13. (a,b) bearing houses 14. (a,b) ventilator in- and outlets

1. Yoke 2. Pole 3. Pole Shoe 4. Field coil 5. Inter Pole 6. Air Gap 7. Armature 8. Slot 9. Teeth 10. Commutator 11. Shaft 12. Base 13. Terminal

pplications of DC Machines In the present day world, electrical energy is generated in bulk in the form of an alternating current. Hence, the use of DC machines, i.e., DC generators and motors are very limited. They are mainly used in supplying excitation of small and medium-range alternators. The Industrial Applications of DC Machines are in Electrolytic Processes, Welding processes and Variable speed motor drives.Nowadays, the alternating current is generated first and then it is converted into DC by the rectifiers. Thus, DC generator has generally been suppressed by a rectified AC supply for many applications. Direct current motors are very commonly used as variable speed drives and in applications where severe torque variations occur. CONCLUSION Electric machine is a general term that refers to machines that use electromagnetic forces to convert electricity. They include generators and motors, which are usually referred to as electromechanical energy converters. Electric machines are responsible for generating almost all of Earth's electric power Electromechanical energy conversion is carried out by using a mechanical field or an electrical field to convert mechanical energy into electrical. Usually, these devices use a magnetic field as their coupling medium. The Industrial Applications of DC Machines are in Electrolytic Processes, Welding processes and Variable speed motor drives.Nowadays, the alternating current is generated first and then it is converted into DC by the rectifiers. Thus, DC generator has generally been suppressed by a rectified AC supply for many applications.

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CAMARINES NORTE STATE COLLEGE COLLEGE OF ENGINEERING ELECTRICAL ENGINEERING DEPARTMENT BACHELOR OF SCIENCE IN ELECTRICAL ENGINEERING

REFERENCE Circuit

Globe (2021).Applications of DC Machines. https://circuitglobe.com/applications-of-dc-machines.html

Retrieved

July

2021from

Electric Machinery Fundamentals Fifth Edition By Stephen J. Chapman Electrical Machines and Drives (Fundamentals and Advanced Modelling) by Jan A. Melkebeek Mr. K.Govindasamy et. At.(2010). Electrical Engineering (Electric Machine and Appliances) ,

Photo Documentation of Conducted Meeting/s

Screenshot photo during meeting and discussion. Screenshot photo of meeting and discussion.

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CAMARINES NORTE STATE COLLEGE COLLEGE OF ENGINEERING ELECTRICAL ENGINEERING DEPARTMENT BACHELOR OF SCIENCE IN ELECTRICAL ENGINEERING

Name: Course & Block: Code – Subject: Activity no.:

Rating: Date of Evaluation:

5.

RUBRIC ASSESSMENT Categories

Quality of Work (5)

Completeness of Content (3)

Not Evident (0 point) Shows poor overall quality of work

Does not include any of the requirements

Authenticity (5)

Shows exemplary overall quality of work

Includes most of the requirements and cites many examples or illustration Draws informed conclusions that are justified with evidence

Includes all the requirements and cites multiple examples or illustration Draws insightful conclusions that are thoroughly defended with evidence and examples Piece was written in an extraordinary style and tone. Very informative and wellorganized Submitted 39% or lower plagiarized output Able to submit the acceptable output within 4 days after the postage

Piece had no style or voice. Gives no new information and very poorly organized.

Piece had little style or voice. Gives some new information but poorly organized.

Piece was written in an interesting style and voice. Somewhat informative and organized

Submitted 100 to 90% plagiarized output No submission

Submitted 89 to 70% plagiarized output Able to submit the acceptable output within 10 days or later after the postage

Submitted 69 to 40% plagiarized output Able to submit the acceptable output within 5-10 days after the postage

TOTAL

Exemplary (3 points)

Shows proficient overall quality of work

Draw logical conclusions, but does not defend with evidence

Timeliness (2)

% Rating=

Proficient (2 points)

Does not draw logical conclusions Critical Thinking (3)

Style of Writing (2)

Need Improvement (1 points) Shows good overall quality of work and there is still room for improvement Includes some of the requirements

Score

60

Score ×50 + 50 60

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