1 / 5

Three-phase Circuits Balanced 3-phase systems Unbalanced 3-phase systems

Three-phase Circuits Balanced 3-phase systems Unbalanced 3-phase systems. SKEE 1043 Circuit Theory. Dr. Nik Rumzi Nik Idris. Unbalanced 3-phase systems. What is unbalanced 3-phase system?. Sources that are unbalanced: unequal magnitude and unequal difference in phase angles

jrosalind
Télécharger la présentation

Three-phase Circuits Balanced 3-phase systems Unbalanced 3-phase systems

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Three-phase Circuits Balanced 3-phase systems Unbalanced 3-phase systems SKEE 1043 Circuit Theory Dr. Nik Rumzi Nik Idris

  2. Unbalanced 3-phase systems What is unbalanced 3-phase system? • Sources that are unbalanced: unequal magnitude and unequal difference in phase angles • Unequal load impedance  only this will be considered in SKEE1043 This will result in unbalanced currents (even though the sources are balanced)  hence for Y connected load, with 4 wire,IN 0 The line or phase currents have to be calculated individually

  3. Unbalanced 3-phase systems Ia A ZA In N C Ib ZB ZC C B Ic What if the system is a 3-wire system (i.e.  or Y)? For Y connected load with 3 wire system, mesh analysis can be used

  4. Unbalanced 3-phase systems A a IAB Z1 Z3 ICA b C B Z2 IBC c

  5. Unbalanced 3-phase systems Power measurement for unbalanced system • Two-wattmeter method is still applicable. However only PT=P1+P2 is true. Reactive power CANNOT be obtained from √3(P2-P1) • For a Y connected, 4 wire system, three wattmeters (instead of two) are needed since In 0 • Again, the line (or phase) currents has to be calculated individually

More Related