Chapter 1 : Three Phase System

Single Phase System A VAa a Alternating current system that has one source/supply A a VAa Teori penjanaan 3 fasa, kebaikan, aplikasi, jenis jujukan

Phasor Diagram VOLTAGE WAVEFORM AND PHASOR DIAGRAM FOR SINGLE PHASE SYSTEM t voltage V1 Phasor Diagram V1

THREE PHASE SYSTEM If three single phase system combined, it will produce THREE PHASE SYSTEM. Voltage in three phase system are equal in magnitude and frequency but out of phase with each other by 120º. So, generated phase voltage had been produced by using three coils that must be rotate through the north and south pole, and these coils must be separated by 120º

Basic Three-Phase Circuit Three-Phase Line Three-Phase Voltage Source Three-Phase Load

3 PHASE VOLTAGE SINUSOIDAL WAVEFORM VA VB VC t 120º Voltan 3 fasa, magnitud dan sudut 240º

Normally, we take VA as a reference to VC and VB. So, there are TWO relationship between voltage VA, VB and VC : VB lagging VA by 120º and VC leading VA by 120º. This is known as Sequence ABC (positive) VB leading VA by 120º dan VC lagging VA by 120º. This is known as Sequence ACB (negatif)

POSITIVE SEQUENCE, ABC NEGATIVE SEQUENCE, ACB Vm: Peak Voltage

POSITIVE SEQUENCE, ABC VC 120º 120º VA 120º Voltan turutan abc VB

NEGATIVE SEQUENCE, ACB VB 120º 120º VA 120º Turutan acb VC

THREE PHASE VOLTAGE SOURCE Y-Connection

THREE PHASE VOLTAGE SOURCE Δ-Connection

Δ-connection

Y-connection

Advantages of three-phase system compare to single-phase system Three-phase transformer is much lighter, better efficiency and more economical compare to single-phase transformer that has same size. Three-phase motor produce permanent torque while single-phase induction motor produce torque in pulse. Three-phase motor have power factor and much better efficiency and small size for the same output compare to single-phase motor. Three-phase motor is self-starter compared to single-phase motor that is not self-starter.

Application of Three Phase System Transformer Electric Motor Three Phase Solid State Relay