Pre-Insertion Resistors – Product Summary
Pre-Insertion Resistors (PIRs) are designed to control transformer magnetising inrush current during energisation, helping to minimise voltage dips in power systems. By limiting transient current at the moment of switching, PIRs reduce network disturbances and improve overall system stability, particularly in distribution and power generation applications.
They provide a simple, robust, and reliable alternative to complex point-on-wave (PoW) switching systems, requiring less precise control while delivering consistent long-term performance across various operating environments.
Key Benefits
Reduces transformer inrush current during energisation
Minimises voltage dips and network disturbances
Supports compliance with grid requirements for voltage stability
Simpler and more reliable than waveform-synchronised switching methods
Suitable for medium and high-voltage power systems
Typical Applications
Power generation and distribution networks
Renewable energy installations (onshore and offshore)
HVDC and grid-connected converter systems
Industrial power plants and substations
Pre-Insertion Resistors offer an effective and dependable solution for managing switching transients and maintaining voltage quality in modern power networks.
