Protection, control and automation proven concept

With all the new requirements and challenges that distribution networks must face, medium voltage switchgears are playing an increasingly important role in the the grid.

Evolving distribution networks require medium voltage switchgears that are more efficient, safe, smart, reliable and environmentally friendly, as well as being easy to engineer, install and operate.

Medium voltage switchgears used for the distribution of electrical energy are a very important part of an electrical network since their function is to ensure uninterrupted power supply to the whole network.

The ABB answer to the latest demanding requirements in distribution networks is the UniSec Digital: it is based on a well proven concept now available also for medium voltage secondary distribution switchgear, which offers significant improvements for customers.

The UniSec Digital solution applies to the safe and reliable ABB UniSec medium voltage switchgear family for secondary distribution.

UniSec switchgear is used to distribute electric power in a variety of demanding applications such as data centers, utility substations, buildings and infrastructure, industries, off-shore platforms, ships and mines.

Applications

For grids
Industries
Data centers
Buildings
Infrastructure

The digitalization of UniSec is based on five key strengths

Safety
• The low energy analog output of the sensors prevents the open current transformer secondary circuit hazards of traditional instrument transformers
• Communication with IEC 61850 protocol reduces the number of wires installed and makes switchgears easier to engineer, build and service
• GOOSE (Generic Object Oriented Substation Event) messaging via the IEC 61850 protocol ensures the switchgears are continuously self-supervised with enhanced error detection
• Safety of the measures
o The output signal from the current sensor is proportional to the derivative of the primary current and this ensures reliable measurements without the saturation effect. It conforms to IEC 61869-10
o The voltage sensor is a passive resistive voltage divider and provides dependable measurements without the ferro resonance effect, in accordance with IEC 61869-11

Savings
• Space saving thanks to limited sensor dimensions
• Less weight thanks to limited sensor size
• Fewer parts to keep in stock since the sensors cover a broad application range
• Significant energy saving during operation thanks to the negligible power consumption of the sensors. Potential savings of up to 250MWh over 30 years

Speed
Reduced lead times with UniSec Digital
• The secondary characteristics of the sensors need not be defined and this speeds up the engineering stage
• The sensors cover a broad range of primary loads, allowing stocks to be used and improving lead times
Last minute customization and changes with UniSec Digital
• Thanks to the technology used, loads can be set at the last minute by simply changing the software parameters of the Intelligent Electronic
Devices (IEDs)
• Thanks to the ABB Relion® relay platform, the switchgear wiring need not be modified. Just update the software within the IED logic

Sustainability
• Universal standard IEC 61850 communication protocol allows the system to be expanded in the future
• Thanks to sensors with broad range capability, future plant load changes can be handled without mechanical reconfigurations or having to replace components, since only a simple modification to the software settings is required, thereby reducing switchgear downtime to a significant extent
• Fewer live parts and materials and less chance of failure reduce aging stress, potential outages and troubleshooting costs
• UniSec Digital has a lower impact on the environment since it requires less material, thereby reducing the amount of waste produced and significantly reducing the CO2 levels by up to 150 tons.
• The system is ready for SCADA or Cloud integration

Simplicity
• Fewer wires to install, commission and maintain thanks to IEC 61850 communication protocol and GOOSE messaging
• The presence of fewer wires that could possibly fail and fewer live parts increases reliability
• Conventional approach
o Twinning the devices must be performed individually per signal
• Horizontal GOOSE communication
o Number of interconnections is equal to number of devices