Transposition tower

{{Short description|Type of electrical transmission tower}}

{{Update|date=March 2024}}

In electrical power transmission, a transposition tower is a transmission tower that changes the relative physical positions of the conductors of a transmission line in a Polyphase system. A transposition tower allows these sections to be connected together, while maintaining adequate clearance for the conductors. This is important since it distributes electrical impedances between phases of a circuit over time, reducing the problem of one conductor carrying more current than others.

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Double-circuit lines are usually set up with conductors of the same phase placed opposite each other. For example, a section of a line may be (top-to-bottom) phases A-B-C on the left, also phases C'-B'-A' on the right. The next section may be B-C-A on the left, also A'-C'-B' on the right. Therefore, the rotation on each side of the tower will be opposite.{{Cite web |last=Technology |first=Electrical |date=2024-04-15 |title=Why are Conductor Positions Swapped in a Transposition Tower? |url=https://www.electricaltechnology.org/2024/04/transposition-tower-position-overhead-conductor-exchanged.html/amp |access-date=2024-08-23 |website=ELECTRICAL TECHNOLOGY |language=en-US}} Transposition helps to reduce the mutual coupling between conductors and between conductors and ground.{{Cite journal |last1=O Donovan |first1=Michael |last2=Barry |first2=Noel |last3=Connell |first3=Joe |last4=Cowhey |first4=Eoin |date=2021-04-02 |title=Mutual Coupling Compensation Techniques Used for Distance Protection of Parallel Lines |journal=Energies |language=en |volume=14 |issue=7 |pages=1982 |doi=10.3390/en14071982 |doi-access=free |issn=1996-1073 }} It also useful in mitigating issues like induced voltages in nearby telephone lines.{{Cite web |title=Inductive Coordination {{!}} The Song of the Open Wire |url=https://the-electric-orphanage.com/wp-inductive-coordination/ |access-date=2025-05-22 |language=en-US}}