Medium voltage encompasses voltages between 1 kV and 36 kV and represents the most important distribution level in the public power grid. It connects high-voltage substations with local distribution substations, which transform the electricity down to low voltage for end consumers. Medium-voltage grids form the actual distribution backbone, to which industrial sites, urban districts, and rural regions connect to the power supply.
Which voltage values belong to medium voltage?
Typical European medium-voltage values are 6 kV, 10 kV, 20 kV, and 30 kV. Internationally, 11 kV, 13.8 kV, and 35 kV are also used. The exact choice depends on grid topology, historical development, and transmission distance. In Germany, medium-voltage grids are often operated as ring or radial networks.
Key Characteristics at a Glance
- Voltage range from 1 kV to 36 kV
- Distribution transformers and cables specifically designed for this range
- Ring operation for higher security of supply
- Connection of industrial customers and decentralized generation plants
- Growing importance due to renewable energy
- Response times of modern medium-voltage protection technology under 100 ms
- Growing importance through the connection of renewable generators
Frequently Asked Questions
Why are there so many different medium-voltage values?
This diversity has grown historically: grids were built up in different eras by different utilities, each using the technically and economically optimal solutions of the time. Today, uniform standards are often pursued when networks are renewed.
What components are typical in a medium-voltage grid?
Distribution transformers, current and voltage transformers, protection relays, and cable terminations are important components. Also added are remote control technology for central monitoring and, increasingly, sensors for online monitoring and smart grid applications.
How is a new industrial customer connected to medium voltage?
Via a customer-side delivery substation with a distribution transformer, metering, and protection technology. The grid operator specifies the connection point and technical conditions. Commissioning, metering, and protection testing are carried out in coordination between the grid operator and the customer.
What developments are shaping modern medium-voltage technology?
Digitalization according to IEC 61850, intelligent distribution substations with sensor technology, automated grid control, and the use of alternative insulating gases are the key developments. The integration of BESS and fast-charging stations also requires adaptations to existing medium-voltage installations.
For your medium-voltage projects – whether new build, expansion, or modernization – we offer comprehensive solutions. Talk to our specialists.