Prepared By: Sheilani Binti Shaari Department of Electrical Engineering/
Course Learning Outcome (CLO) Upon completion of this course, students should be able to: Apply the principles of three phase systems, balanced load, star and delta type of connection to solve electrical circuit correctly.
CONTENT 1.INTRODUCTION 2.3 PHASE SYSTEM 3.DIFFERENCE 3 PHASE & 1 PHASE 4.3 PHASE LOAD CONNECTION 5.3 PHASE POWER
LEARNING OUTCOMES General Objective (GO) Student should be able to understand the basic principles of a three phase system. Specific Objectives(SO) Student should be able to: 1. Define three phase system with diagram. 2.Differentiate between three phase system and single phase system 3.State three phase supply consists of three phase conductors.
INTRODUCTION Generation System Transmission System Distribution System 240v 11kv 132kv 415v Three phase Single phase
INTRODUCTION 3Phase System Is 3 separate coil conductors which 120 o apart Produce 3 voltage source with same magnitude but different phase 120 o.
INTRODUCTION Three-phase system have 3 phase conductor or live wire : 1. Red Phase, R 2. Yellow Phase, Y 3. Blue Phase, B Y 120 240 0 R B
3Ф SYSTEM emf is generated using 3 conductor conductors have the same coils and rotating at a constant speed R B Y Y B R
3Ф SYSTEM the emf generated has the same three-emf amplitude or peak value with phase shift of 120 and same frequency. B R Y
3Ф SYSTEM Dge E m sin 0 E m sin 120 o E E R E Y E B m E m sin 240 o 0 120 240 θ Waveform of 3Ф System
3Ф SYSTEM E = E sinθ R m emf E m E R E Y E B E = E sin( θ 120 ) Y m E E sin( B m = sin( θ o o 240 ) 0 120 240 θ Equations of 3Ф System
3Ф SYSTEM emf E E R E Y E B m o m E = 120 0 120 240 E E R Y B E m = 2 E 2 E m = 2 0 o 240 θ o Equations of 3Ф System represent in a form of phase
DIFFERENT 3Ф & 1Ф SYSTEM 3Ф SYSTEM Definition: System with 3 live cabels from supply to load : Red phase(r), Yellow phase (Y) and Blue phase (B). Definition: 1Ф SYSTEM System with 2 cable connecting from source to load: Life cable (L) and neutral cable (N).
DIFFERENT 3Ф & 1Ф SYSTEM 3Ф SYSTEM Connection: R 1Ф SYSTEM Connection: L Y 240v 415v 240v Load B N N
DIFFERENT 3Ф & 1Ф SYSTEM 3Ф SYSTEM Waveform: V R Y B 415 1Ф SYSTEM Waveform: V 240 0 120 240 Ө 0 90 180 Ө
APPLICATIONS OF 3Ф SYSTEM 1. Transmission system 2. Supply power to large factories 3. Starting the 3Ф machines.
ADVANTAGES OF 3Ф SYSTEM More economical due to less construction and maintenance costs conductor used is smaller, thus the needs of copper can be reduced.
ADVANTAGES OF 3Ф SYSTEM Easy to installed due to smaller and lighter cable used. Therefore the smaller structures supporters can be used and the distance between the supporters can be relatively long.
ADVANTAGES OF 3Ф SYSTEM The characteristics of 3Ф equipment have a better operating starting due to its stable and fixed power. Electrical energy supplied is higher than 1Ф.
ADVANTAGES OF 3Ф SYSTEM Most large motors used for induction motor 3Ф can stand alone without the additional equipment such as capacitors, centrifugal switches or other additional circuits
ADVANTAGES OF 3Ф SYSTEM The output Production and equipment quality of work for 3Ф system is better than 1Ф because of the higher efficiency and power factor.
CONTENT 1.INTRODUCTION 2.3 PHASE SYSTEM 3.DIFFERENCE 3 PHASE & 1 PHASE 4.3 PHASE LOAD CONNECTION 5.3 PHASE POWER
LEARNING OUTCOMES General Objective (GO) Student should be able to understand the basic principles of a three phase system. Specific Objectives(SO) Student should be able to: 1. State that three phase loads can be connected in delta or star. 2.State balanced star and delta connection. 3.Determine the power in three phase system.
CONTENTS 3PHASE LOAD CONNECTION STAR CONNECTION 3PHASE VOLTAGE AND CURRENT DELTA CONNECTION 3PHASE VOLTAGE AND CURRENT 3PHASE POWER APPARENT POWER, REAL POWER AND REACTIVE POWER
3Ф LOAD CONNECTION Load on each phase is usually balanced. The connections have 4 conductor 3 live wire and 1 neutral wire: Red Line, R Yellow Line,Y Blue Line, B Neutral line, N
3Ф LOAD CONNECTION There are 2 methods of load connection in 3Ф system DELTA ( ) STAR ( Y )
STAR CONNECTION R Load N Load Load Y B
STAR CONNECTION Line Voltage (V L ) voltage that measure between 2 life wire. - E RY, E YB dan E BR
STAR CONNECTION Phase Voltage (V P ) Voltage that measure between life and neutral wire - E RN, E YN dan E BN
STAR CONNECTION R V L = E RB V V P = E RN L = E YR Load N V P = E BN V P = E YN Load Load Y B V L = E BY
STAR CONNECTION Voltage Formula Line Voltage = 3 Phase Voltage V L = 3 V P
STAR CONNECTION Line Current (I L ) Current that flow in line - I R, I Y and I B
STAR CONNECTION Phase Current (I P ) Current that flow in phase - I PR, I PY and I PB
STAR CONNECTION R N I L = I R I P = I PR Load Load I L = I Y I P = I PY Load Y I P = I PB B I L = I B
STAR CONNECTION Current Formula Line Current = Phase Current I L = I P
STAR CONNECTION Example 3 ballance load STAR connection have 10Ω resistance and 0.019H inductance. The supply voltage is 415V, 50Hz. Calculate: i. Line voltage, ii. Phase voltage, iii. Line current and iv. Phase current
DELTA CONNECTION R Load Load Y Load B
DELTA CONNECTION V L V L Load V P Load Y Load V L
DELTA CONNECTION Voltage Formula Line Voltage = Phase Voltage V L = V P
DELTA CONNECTION I L = I R I P = I PR Y I L = I Y I P = I PY I L = I B Load Load Load I P = I PB
DELTA CONNECTION Current Formula Line Current = 3 Phase Current I L = 3 I P
DELTA CONNECTION Example 3 ballance load DELTA connection have 10Ω resistance and 0.019H inductance. The supply voltage is 415V, 50Hz. Calculate: i. Line voltage, ii. Phase voltage, iii. Line current and iv. Phase current
3Ф POWER Power in 3 phase is the same as in single phase 3 types three phase power: 1. Apparent Power, 2. Active / Real Power and 3. Reactive / Reactance Power
APPARENT POWER Single Phase : 3Ф Phase : S = V I P P P VA S = 3 xs 3 Φ P = V P I P 3 L = 3V L I VA
REAL POWER Single Phase : P = V P P I P cosθ W 3Ф Phase : P = 3xP 3 Φ P = = 3V I P P 3 V L I L cosθ cosθ W
REACTIVE POWER Single Phase : Q =V P P I VAR P sinθ 3Ф Phase : Q = 3xQ 3 Φ P = 3V I sinθ P P = 3 V L I L sinθ VAR
POWER TRIANGLE Q = V P P IP sinθ S =V P P I P Q S S3Φ = 3V I L L Q3Φ = 3 V L I L sinθ θ P P = V P P I cosθ P 3P Φ = 3V I θ L cos L
3Ф POWER Example Calculate: i. Apparent power, ii. Real power, iii. Reactive power for both connections in previous example.
SOLVE PROBLEMS (Q1 Q13)
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