What is meant by Symmetrical Components?

Electrical
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What is meant by Symmetrical Components?

Voltages and currents in a three-phase power system can become unbalanced as a result of faults, load imbalance (or) equipment failure. To analyze these conditions, π‘Ίπ’šπ’Žπ’Žπ’†π’•π’“π’Šπ’„π’‚π’ π’„π’π’Žπ’‘π’π’π’†π’π’•π’” are utilized:

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𝟏). π‘·π’π’”π’Šπ’•π’Šπ’—π’† 𝑺𝒆𝒒𝒖𝒆𝒏𝒄𝒆

Three voltages or currents of equal amplitude.

They’re separated by 120Β°.

Rotate the same way as the original system.

Represents the electricity system’s regular operating condition.

𝑬x: A healthy system has a balanced positive sequence of phase voltages (Va, Vb, Vc).

𝟐). π‘΅π’†π’ˆπ’‚π’•π’Šπ’—π’† 𝑺𝒆𝒒𝒖𝒆𝒏𝒄𝒆

Three voltages or currents of equal magnitude.

Separated by 120Β°, but spin in the opposite direction as the original arrangement.

Caused by imbalanced faults (such as line-to,line or unbalanced loads).

Harmful to motors & generators due to increased temperature.

𝑬x: A single-phase-to-ground fault causes negative sequence components.

πŸ‘). 𝒁𝒆𝒓𝒐 𝑺𝒆𝒒𝒖𝒆𝒏𝒄𝒆

Three voltages (or) currents have identical magnitude and phase (0Β° shift).

Typically connected with earth faults.

Exists when there is a return path (for example, through neutral/ground).

𝑬x: A single-line-to-ground fault in a system with a grounded neutral will result in high zero-sequence current.

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