35kV main busbars are classified into several types

35kV main busbars are classified based on configuration, material, and design, including single bus, double bus, ring bus, and flexible or laminated types.

Busbar Configurations

1. Single Bus: A simple layout where all incoming and outgoing feeders connect to one main bus. It is cost-effective and easy to operate but lacks redundancy, so any fault requires a shutdown of the bus section for maintenance or repair . 2. Double Bus: Features two main buses with tie breakers, allowing one bus to take over if the other fails. This configuration improves reliability and is commonly used in critical substations . 3. Ring Bus (Ring Main): A looped system where power can flow in either direction. It provides high reliability and flexibility, allowing maintenance on one section without interrupting supply . 4. Sectionalized Bus: A single bus divided into sections using bus couplers and isolators. This limits the impact of faults and allows partial operation during maintenance . 5. Double Breaker/Double Bus: Each feeder is connected to two breakers and two buses, offering maximum reliability and operational flexibility, often used in high-criticality installations .

Busbar Materials

1. Copper Busbars: High conductivity, durable, and corrosion-resistant, ideal for high-current applications in switchgear, transformers, and industrial power distribution . 2. Aluminum Busbars: Lightweight and cost-effective, suitable for installations where weight and budget are concerns, though slightly lower in conductivity than copper .

Busbar Design Types

1. Flat Strip: Most common, provides good heat dissipation and easy connection points . 2. Tubular (Hollow): Reduces weight and improves cooling through airflow . 3. Round Rod: Simple applications or where bending is required . 4. Laminated or Flexible Busbars: Multiple thin layers or braided conductors, used in tight spaces or where vibration and thermal expansion must be accommodated . 5. Air-Insulated Busbars (AIS): Bare or plated conductors mounted on insulators with controlled air gaps, common in outdoor substations . 6. Sandwich-Type Busbars: Conductors packed together with insulating layers, often plated to reduce corrosion and improve conductivity .

Summary

The classification of 35kV main busbars depends on configuration (single, double, ring, sectionalized), material (copper, aluminum), and design (flat, tubular, laminated, flexible, air-insulated, sandwich-type). Selection is guided by factors such as reliability, fault tolerance, thermal performance, space constraints, and cost, ensuring safe and efficient power distribution in medium-voltage systems .