• During EHV (Extra High Voltage) and UHV (Ultra High Voltage) stringing, multiple sub-conductors (e.g., 2, 4, or 6 bundles per phase) must be pulled simultaneously under identical tension. Unequal tension leads to sub-conductor twisting, strand deformation, uneven sag profiles, and structural imbalance on tower cross-arms.

Modern hydraulic stringing equipment achieves synchronization through integrated hydraulic power units with proportional flow-divider valves and electronic closed-loop monitoring:

• Independent Hydraulic Circuit Control: Each bullwheel set is driven or braked by independent hydraulic motors linked through a master manifold.

• Constant Tension Control Systems (CTCS): CTCS automatically senses speed and tension differentials between individual conductors. If one sub-conductor encounters higher friction or terrain resistance, the system dynamically adjusts hydraulic pressure to balance payout speed and maintain uniform tension within $\pm 1\%$ variance.

• Running Board Alignment: Multi-conductor running boards equipped with balance swivels ensure that all sub-conductors pass through stringing blocks without wrapping or flipping.

Ningbo Changshi’s multi-drum pullers and multi-bullwheel tensioners incorporate digital CTCS control panels, allowing operators to monitor and record real-time tension parameters for every sub-conductor simultaneously.