1 Sl No Computer Aided Electrical Drawing Laboratory Manual Table of Contents Name of the drawing Page Number 1. Basic drawing commands for autocad 4 2. Standard Electrical component symbols. 10 3. 4. 5. 6. 7. 8. 9. Design and draw Developed simplex armature winding diagram of DC Motor/Generator with 4 Pole, 14 slots, double layer progressive lap winding. Draw the sequence diagram. Show the position of brush & direction of current. Draw and Develop a single layer winding for a DC Machine having 32 armature conductors with 4 poles. Mark the poles. Draw the sequence diagram and also show the position of brush & direction of induced current & give equalizer connection. Draw and develop the single layer lap winding diagram of a DC motor having 4 poles with 26 slots. Mark the poles. Draw the sequence diagram and also show the position of brush & direction of induced current. Draw and develop the double layer lap winding diagram of a DC machine having 6 poles, 18 slots with full pitch. Mark the poles. Draw the sequence diagram and also show the position of brush & direction of induced current. Draw and develop the single layer lap winding diagram of a DC machine having 4 poles, 30 conductors. Mark the poles. Draw the sequence diagram and also show the position of brush & direction of induced current. Draw and develop the duplex lap type winding diagram of a DC machine having 4 poles, 32 conductors. Mark the poles. Draw the sequence diagram and also show the position of brush & direction of induced current. Draw and develop the simplex wave with single layer winding diagram of a DC machine having 4 poles, 42 conductors. Mark the poles. Draw the sequence diagram and also show the position of brush & direction of induced current. 12 13 14 15 16 17 18 10 11 12 Draw and develop the lap type single layer winding diagram of AC machine having 4 poles, 24 slots, 3 phases with coil short pitched by one slot and star connected. Mark the poles. 19 Draw and develop the lap type single layer winding diagram of a 3 phase induction motor having 2 poles, 18 slots with coil full pitched and delta connected. Mark the poles. 20 Draw and develop the lap type single layer winding diagram of a 3 phase AC Machine having 2 poles, 24 slots with coil short pitched by one slot and star connected. Mark the poles. 21
2 13 14 15 16 Draw and develop the lap type single layer winding diagram of a 3 phase AC Machine having 4 poles, 36 slots with coil full pitched and star connected. Mark the poles. 22 Draw and develop the wave type single layer winding diagram of a 3 phase AC Machine having 4 poles, 24 slots with coil full pitched and delta connected. Mark the poles. 23 Design & draw the developed winding diagram of AC machine with following details: No of poles=4, No. of slots=36, single layer wave star connected. 24 Draw and develop the lap type double layer winding diagram of a 3 phase AC Machine having 4 poles, 24 conductors with coil full pitched and star connected. Mark the poles. 25 17 Draw and develop the lap type double layer winding diagram of a 3 phase induction motor of 5HP, 440V having 4 poles and 2 slots/pole/phase with coil full pitched and delta connected. Mark the poles. 26 18 19 20 21 Draw and develop the lap type double layer winding diagram of a 3 phase, 3000rpm, 50Hz AC Machine 24 slots with short pitch by 5/6 th pitch and star connected. Mark the poles. 27 Draw and develop the mush type armature winding diagram of a 3 phase, 4 poles with 36 slots. 28 Draw and develop the half coiled single layered concentric winding diagram of a 3 phase, 4 poles with 24 slots and 60 0 phase spread. 29 Draw and develop the whole coiled single layer concentric winding diagram of a 3 phase, 4 poles with 24 slots and 60 0 phase spread. 30 22 23 24 Draw single line diagram with two incoming feeder,110kv, 6 outgoing lines,11kv,2 double bus bar-110kv,11kv, one auxiliary transformer 5MVA,11kV/415V 3 phase, wave trap coupling condensers, earth switch, OCBs, CT,PT Draw the single diagram of substation having 2 220kV incoming lines,5-outgoing lines with 66kV,11kV, bus bar: 220kV double bus, 11kV bus, Transformer :( i) 3 winding two 100MVA 220/66/11kV. (ii) Auxiliary transformer one 11kV/400V, Wave trap, Earthing condenser, and Earth switch at incoming lines. Show the position of CTs, PTs disconnecting switches, lightning arresters and circuit breakers. Draw the single diagram of substation having two 110kV incoming lines, outgoing lines with 110kV-one, 11kV-4nos, Transformer :( i) two 10MVA 110/11kV. /Y (ii) one-2mva, 11kV/415V y/y. Bus bar 110kV duplicate bus bar, 11kV single bus bar Show the position of CTs, PTs disconnecting switches, lightning arresters and circuit breakers. Draw the single diagram of 66/11kV substation having following equipments: (i) two transformer :66/11kV,5MVA / 3 phase (ii) 66kV double bus bar with bus coupler,11kv 25 single bus with sectionalisation (iii) two incoming lines 66kV (iv) two outgoing lines 66kV (v) eight outgoing lines at 11kV distributed equally Show the position of CTs, PTs disconnecting switches, lightning arresters and circuit breakers. 31 32 33 34
3 26 Draw single line diagram of a 33/11kV substation having the details as (i) incoming line:one,33kv (ii) outgoing line:six,11kv (iii) transformer: (a) 9MVA,33/6.4/0.695kV, /Y/Y (b) two, 6.3 MVA,33/11kV, /Y equally Show the position of CTs, PTs disconnecting switches, lightning arresters and circuit breakers. 35 27 Draw the single line diagram of a pole mounted substations. 36 28 References: 37
4 BASIC DRAWING COMMANDS FOR AUTOCAD Measuring Commands GRID: Displays a grid of dots at a desired spacing on the screen. Command: GRID (enter) On/Off/Tick spacing(x)/aspect: (enter value) (enter) SNAP: Specifies a "round off" interval so that points entered with the mouse can be locked into alignment with the grid spacing. Basic Draw Commands Command: SNAP (enter) On/Off/Value/Aspect/Rotate/Style: (enter value) (enter) CIRCLE: Draws circles of any size. Command: Circle (enter) 3P/2P/TTR/<center point>: (pick a center point) Diameter or <Radius>: (Pick a point on the circle) LINE: Draws straight lines between two points Command: LINE (enter) From Point: (pick a point using the mouse) To Point: (Pick a point using the mouse) To Point: (Press return to end the command) ARC: Draws an arc (any part of a circle or curve) through three known points. Command: ARC (enter) Center/ < Start point > : (pick the first point on the arc) Center/End/ < Second point > : C Center: (pick the arc's center point) Angle/Length of chord/ <End point > : (pick the arc endpoint) Display Commands LIMITS: Sets the size of the drawing paper. For size "A" drawing paper the limits should be set for 10.5 x 8. Command: LIMITS (enter)
5 On/Off/Lower left corner <0.0000> (enter) Upper right corner: 10.5,8 (enter) ZOOM: Enlarges or reduces the display of a drawing. Command: ZOOM (enter) All/Center/Dynamic/Extents/Left/Previous/Vmax/Window/<Scale(x/XP)>: (pick a point to define one corner of a rectangular viewing window then pick a point to define the second point to define the opposite diagonal corner of the viewing window) Note: To return the picture to its original viewing size enter ALL and press the enter key when prompted instead of defining a window. PAN: Allows you to move your view point around the drawing without changing the magnification factor. Editing Commands Command: PAN (enter) CHANGE: Alters properties of selected objects Command: CHANGE (enter) Select objects or window or Last (select objects to be changed) Properties/<Change point>: (type P) Change what property (Color/Elev/LAyer/LType/Thickness)? (type Layer) New Layer: (enter new layer name and press enter) ERASE: Erases entities from the drawing. Command: ERASE (enter) Select objects or Window or Last: (Select objects to be erased and press enter when finished) EXTEND: Lengthens a line to end precisely at a boundary edge. Command: Extend (enter) Select boundary edge(s)... Select Objects (pick the line which represents the boundary edge which lines will be extended to) (press enter when finished selecting cutting edges) <Select object to extend>/undo: (pick the line(s) that need to be extended
6 TRIM: Trims a line to end precisely at a cutting edge. Command: Trim (enter) Select cutting edge(s)... Select Objects (pick the line which represents the cutting edge of line in which objects will be trimmed to) (press enter when finished selecting cutting edges) <Select object to trim>/undo: (pick the line(s) that need to be trimmed) GRIPS You can edit selected objects by manipulating grips that appear at defining points on the object. Grips is not a command. To activate grips simply pick the object. Small squares will appear at various entity-specific positions. By selecting an end grip you can stretch the entity to change its size. By selecting the center grip you can move the entity to a new location. To remove grips press CTL-C twice. You can perform the following using grips: Copy, Multiple Copy, Stretch, Move, Rotate, Scale, and Mirror. Creating Layers LAYER: Creates named drawing layers and assigns color and linetype properties to those layers. Construction Commands Command: LAYER (enter) A Layer & Line type Properties dialog box will be displayed. To add a new layer, pick the New button. A new layer listing appears, using a default name of Layer1. the layer name can be changed by highlighting the layer name. Colors and Line types can be assigned to each new layer by picking the color box to assign a color and picking the line type box to assign a line type. Standard AutoCAD colors 1 = Red 2 = Yellow 3 = Green 4 = Cyan 5 = Blue 6 = Magenta 7 = White Standard AutoCAD line types Hidden2 = hidden lines Center2 = center lines Phantom2 = phantom or cutting-plane lines ARRAY: Makes multiple copies of selected objects in a rectangular or circular pattern Command: ARRAY (enter)
7 Select objects or Window or Last: (select object to array) Rectangular or Polar array (R/P) <current>: (P) Center point of array: (pick the point around which to form the array) Angle to fill (+=CCW, -=Cw) <360>: (enter) COPY: Draws a copy of selected objects. Command: COPY (enter) Select objects or Window or Last: (select objects to be copied) Base point or displacement: (pick a point on the object to be use as a reference point) Second point of displacement: (pick a point which represents the new location of the copied object) MIRROR: Makes mirror images of existing objects. Command: MIRROR (enter) Select objects or Window or Last: (select objects to be mirrored) First point of mirror line: (pick a point on top of the mirror line) Second point: (pick a point on the bottom of the mirror line) Delete old objects? <N> y or n (enter) MOVE: Moves designated entities to another location. Command: MOVE (enter) Select objects or Window or Last: (select objects to move) Base point or displacement: (pick a point on the object to be use as a reference point) Second point of displacement: (pick a point which represents the new location of the object) OFFSET: Constructs an entity parallel to another entity at a specified distance. Offset can be used with lines, circles, arcs, and polylines. Command: OFFSET (enter) Offset distance or Through <last>: (enter a distance value) Select object to offset: (select object to offset) Side to offset: (Pick any point on the side of the object you wish to offset)
8 FILLET: Changes any corner to a rounded corner. Command: FILLET Polyline/Radius/Angle/Trim/Method/ <Select first line > : (pick the first line) Select second line: (pick the second line) CHAMFER: Changes any corner to an angled corner. Command: CHAMFER Polyline/Distance/Angle/Trim/Method/ < Select first line > : (pick the first line) Select second line: (pick the second line) OSNAP Instantly locates exact points relative to existing objects (points). Object Snap Modes: Endpoint, Midpoint, Center, Quadrant, Intersection, Insertion, Perpendicular, Tangent, Nearest, Node, and None. Placing lettering on a drawing TEXT: Draws text characters of any size. Command: TEXT (enter) Justify/Style/<Start point>: (pick a starting point or enter a justification letter) Height (0) (enter the height of the lettering) Rotation Angle (0) (enter) Text: (enter the desired lettering) (enter) Summary of Options <Start Point> Justify Style Null reply Left-Justifies text along its baseline Justifies text according to the alignment options Enters a new text style Enters a new line of text below the previous text. Text Alignment Options (space or Enter key will give a Null reply) Alignment Abbreviation Orientation Aligned A Aligns text between two points. Text height will adjust automatically
9 Fit F Fits text between two points. Text height will not change Centered C Centers text at the baseline of a specified point Middle M Centers text horizontally and vertically at the baseline of a specified point Right R Right Justify text at the baseline of a specified point Top Left TL Left Justifies text at the top of text Top Center TC Centers text at the top of text Top Right TR Right justifies text at the top to text Middle Left ML Left justifies text at the middle of text Middle Center MC Centers text both horizontally and vertically at the middle of the text Middle Right MR Right justifies text at the middle of text Bottom Left BL Left justifies text at the bottom of text Bottom Center BC Centers text a the bottom of text Bottom Right BR Right justifies text at the bottom of text The SPELL command will check the spelling of a group of text. Cross hatching a drawing BHATCH: Allows the user to crosshatch areas of a section view. Command: BHATCH (enter) The Boundary Hatch dialogue Box will be displayed. Select the Hatch Options box. The Hatch Options box will be displayed. Select the Patterns box. The Choose Hatch Pattern box will be displayed. Select the desired hatch pattern. The Hatch Options box will be displayed again. You can select a scale and rotation angle for the crosshatch pattern. Select the OK box when finished. The Boundary Hatch dialogue box will be displayed again. Select the Pick Points box. When prompted, select the internal point of the crosshatched. Press the enter key when finished. The Boundary Hatch dialog box will be displayed again. Select the Apply box to add the crosshatching to the drawing.
10 Standard Electrical component symbols
11
12 DC Winding -Design Problem-1 Design and draw Developed simplex armature winding diagram of DC Motor/Generator with 4 Pole, 14 slots, double layer progressive lap winding. Draw the sequence diagram. Show the position of brush & direction of current. Solution: Pole pitch = Number of conductors/pole = 28/4 = 7 We have pole pitch = (Yb + Yf ) / 2 = Yp Hence (Yb + Yf) = 14..(1) (Yb - Yf ) = 2...(2) Solving above equations Yb = 8 and Yf = 6 back pitch yb = 2c/p ± k For lap winding both Yb and Yf must be odd and differ by 2. Satisfying the above condition Yb = 7 and Yf = 5. Winding table Developed Winding Diagram Sequence Diagram
13 DC Winding -Design Problem-2 Draw and develop single layer winding for a DC Machine having 32 armature conductors with 4 poles. Mark the poles. Draw the sequence diagram and also show the position of brush & direction of induced current & give equalizer connection. Solution: Winding table Developed Winding Diagram Sequence Diagram
14 DC Winding -Design Problem-3 Draw and develop the single layer lap winding diagram of a DC motor having 4 poles, 26 slots with. Mark the poles. Draw the sequence diagram and also show the position of brush & direction of induced current. Solution: Winding table Developed Winding Diagram Sequence Diagram
15 DC Winding -Design Problem-4 Draw and develop the double layer lap winding diagram of a DC machine having 6 poles, 18 slots with full pitch. Mark the poles. Draw the sequence diagram and also show the position of brush & direction of induced current. Solution: P=6, No of slots = 18, conductor =36, pole pitch= 36/6=6. YA=YB+YF=12, YB= YF-2 (FOR PROGRESSIVE WINDING) So YB-YF=2; YB=7,YF=5 Winding table Developed Winding Diagram Sequence Diagram
16 DC Winding -Design Problem-5 Draw and develop the single layer lap winding diagram of a DC machine having 4 poles, 30 conductors. Mark the poles. Draw the sequence diagram and also show the position of brush & direction of induced current. Solution: P=4, conductor =30, pole pitch= 30/4=7.5 YA = YB+YF =14, YB= YF - 2 (FOR PROGRESSIVE WINDING) So YB-YF=2; YB= 8,YF=6 Winding table Developed Winding Diagram Sequence Diagram
17 DC Winding -Design Problem-6 Draw and develop the duplex lap type winding diagram of a DC machine having 4 poles, 32 conductors. Mark the poles. Draw the sequence diagram and also show the position of brush & direction of induced current. Solution: Winding table Developed Winding Diagram
18 DC Winding -Design Problem-7 Draw and develop the simplex wave with single layer winding diagram of a DC machine having 4 poles, 42 conductors. Mark the poles. Draw the sequence diagram and also show the position of brush & direction of induced current. Solution: Winding table Developed Winding Diagram Sequence Diagram
19 AC Winding -Design Problem-1 Connections: Rs=1 Ys=1+ (120/slot angle)= 1+(120/30)=5 Bs=1+ (240/slot angle)= 1+(240/30)=1+8=9 First pole Second pole Third pole Fourth pole R phase 1,6 7,12 13,18 19,24 B phase 3,8 9,14 15,20 21,2 Y phase 5,10 11,16 17,22 23,4
20 AC Winding -Design Problem-2
21 AC Winding -Design Problem-3
22 AC Winding -Design Problem-4
23 AC Winding -Design Problem-5
24 AC Winding -Design Problem-6 Winding table First pole Second pole Third pole Fourth pole R phase 1(s),2,3 10,11,12 19,20,21 28,29,30 B phase 4,5,6 13(s),14,15 22,23,24 31,32,33 Y phase 7(s),8,9 16,17,18 25,26,27 34,35,36
25 AC Winding -Design Problem-7 Winding table First pole Second pole Third pole Fourth pole R phase 1+3=4' 4+3=7' 7+3=10' 10+3=1' B phase 2+3=5' 5+3=8' 8+3=11' 11+3=2' Y phase 3+3=6' 6+3=9' 9+3=12' 12+3=3'
26 AC Winding -Design Problem-8 Winding table First pole Second pole Third pole Fourth pole R phase 1+6=7',2+6=8' 7+6=13',8+6=14' 13+6=19',14+6=20' 19+6=25'(1'),20+6=26'(2') B phase 3+6=9',4+6=10' 9+6=15',10+6=16' 15+6=21',16+6=22' 21+6=27'(3'),22+6=28'(4') Y phase 5+6=11',6+6=12' 11+6=17',12+6=18' 17+6=23',18+6=24' 23+6=29'(5'),24+6=30'(6')
27 AC Winding -Design Problem-9 Draw the developed winding diagram of an AC machine with the following details: Speed= 3000rpm, No.of slots=24, frequency =50Hz, phase=3, short pitch by 5/6 th pitch, double layer lap & Y connected. Solu: P=120f/N =(120x50)/3000=2, Pole pitch=24/2=12,no of slots/pole/phase=24/2/3=4 Slot angle=180/12=15 0, Coil span=180x5/6=150 0.= 10. Rs=1, Ys=1+120/15=9, Bs=1+240/15=17 Winding table First pole Second pole R phase 1+10=11',2+10=12',3+10=4',4+10=14' 13+10=23',14+10=24',15+10=25'(1'),16+10=26'(2') B phase 5+10=15',6+10=16',7+10=17',8+10=18' 17+10=27'(3'),18+10=28'(4'),19+10=29'(5'),20+10=30'(6') Y phase 9+10=19',10+10=10',11+10=21',12+10=22' 21+10=31'(7'),22+10=32'(8'),23+10=33'(9'),24+10=34'(10') Assignment: Draw the developed winding diagram:
28 AC Winding -Design Problem-10
29 AC Winding -Design Problem-11 Draw and develop the half coiled single layered concentric winding diagram of a 3 phase, 4 poles with 24 slots and 60 0 phase spread.
30 AC Winding -Design Problem-12 Draw and develop the whole coiled single layer concentric winding diagram of a 3 phase, 4 poles with 24 slots and 60 0 phase spread. Solution:
31 Single line diagram of substation-design Problem-1 Draw single line diagram with two incoming feeder,110kv, 6 outgoing lines,11kv,2 double bus bar- 110kV,11kV, one auxiliary transformer -5MVA,11kV/415V 3 phase, wave trap coupling condensers, earth switch, OCBs, CT,PT
32 Single line diagram of substation-design Problem-2
33 Single line diagram of substation-design Problem-3
34 Single line diagram of substation-design Problem-4
35 Single line diagram of substation-design Problem-5
36 Single line diagram of substation-design Problem-6
37 References: [1] CAD for Electrical Engineers by M.S Indira, V.D. Sankaralal and D.Beula. [2] A.K.Sawhney,"A course in Electrical Machine Design", Dhanpat Rai & sons,1997. [3]Cheryl R.Shrock,"AutoCAD Pocket Reference ",BPB Publications 2010. [4] Open Education Resource: Flipping the classroom with MOODLE : "Example by IDP in Educational Technology, IIT Bombay"