Højspændingsdistribution

Højspændingsdistribution refers to the system of delivering electrical power at high voltages, typically above 33 kV, from power plants to the distribution network that feeds households, businesses and industry. The primary purpose of using high voltage in transmission and substations is to reduce the current for a given power level, thereby lowering resistive losses and enabling efficient long‑distance transport.

In a typical grid, power generated at a plant is stepped up to 400 kV or higher in a transformer before it is sent along transmission lines. At regional substations the voltage is reduced to medium‑voltage levels such as 110 kV, 66 kV or 33 kV. From there, a second set of substations further steps the voltage down to low voltage levels – 10 kV or 20 kV – which are then distributed by feeder lines to finally drop the voltage to 230 V (or 400 V three‑phase) for end use.

Key components of a højspændingsdistribution system include high‑voltage transformers, circuit breakers, disconnect switches, branch circuit controllers and protective relays. Overhead lines are favoured for long spans due to lower cost, while underground cables offer protection against weather but are more expensive. The system is governed by national standards such as the Danish technical regulations for power distribution and international guidelines from organizations like IEC.

Safety is paramount; clearance distances between conductors and surroundings, protective earth schemes, and isolation procedures limit the risk of electrical shock. Regular maintenance, monitoring of insulation levels, and scheduled testing are required to ensure reliability and compliance with regulatory requirements.