introduction 2 types ; i. star network ii. delta network
DESCRIPTION
INTRODUCTION 2 TYPES ; i. STAR NETWORK ii. DELTA NETWORK. 3 NETWORK TERMINAL. TRANSFORMATION STAR - DELTA. A. Ra. R1. R3. N. Rc. Rb. C. B. R2. c. B. DELTA. STAR. FORMULA ;. Transform star to delta R1 = Ra + Rb + RaRb/Rc R2 = Rb + Rc + RbRc/Ra R3 = Ra + Rc + RaRc/Rb. A. R3. - PowerPoint PPT PresentationTRANSCRIPT
3 NETWORK TERMINAL3 NETWORK TERMINAL
INTRODUCTIONINTRODUCTION
2 TYPES ;2 TYPES ;
i. STAR NETWORKi. STAR NETWORK
ii. DELTA NETWORKii. DELTA NETWORK
INTRODUCTIONINTRODUCTION
2 TYPES ;2 TYPES ;
i. STAR NETWORKi. STAR NETWORK
ii. DELTA NETWORKii. DELTA NETWORK
TRANSFORMATION STAR - DELTA
Rc
Ra
Rb
A
A
R1R3
A
R1R3
cB
BC
STAR DELTA
R2
R1R3
Ra
RbRc
A
N
FORMULA ;Transform star to delta
• R1 = Ra + Rb + RaRb/Rc
• R2 = Rb + Rc + RbRc/Ra
• R3 = Ra + Rc + RaRc/Rb
TRANSFORMATION DELTA-STAR
Rc
Ra
Rb
AA
BC
A
R1R3
A
R1R3
A
BC
R1
R2
R3
Ra
RbRc
N
FORMULA ;Transform delta to star
• Ra = R1R3/ R1+R2+R3
• Rb = R1R2 / R1+R2+R3
• RC = R2R3/ R1+R2+R3
EXAMPLEProblem 1Refer to the circuit below, transform
the circuit to Star networkA
R1R3
A
R1R3
A
BC
8
6
4
• Answer • Ra = 8x4 / (8+6+4)• = 32/18 = 1.78 Ω• Rb = 8x6/ (8+6+4)• = 48/18 = 2.67Ω• Rc = 6x4 / (8+6+4)• = 24/18 = 1.33Ω
EXAMPLEProblem 2Refer to the circuit, calculate ;i. Equivalent resistance, RT
ii. Total of current, IT40
50
20
10 30
30V
A
BC
Solution ;The steps ;1.Mark points A, B, C at each node
to represent each of the resistance R1, R2 and R3.
2.Draw the Delta with the resistances taken as R1, R2 and R3.
3.Convert Delta to Star shape to find the value of Ra, Rb and Rc
• Ra = 20 ohm• Rb = 5 ohm• Rc = 4 ohm
A
R1R3
A
R1R3
Answer ;
(i) RT = 22.67 Ω(ii) IT = V/RT =
30/22.67 = 1.32 A
EXAMPLEProblem 3Refer to the circuit,
calculate ;i. Equivalent
resistance, RT
ii. Total of current, IT