Medium voltage digitalisation makes distribution grids more transparent, efficient and future-proof.
The future of the medium voltage grid is digital. That’s why many network operators are due to modernise their substations. Speed and scope both depend on the technical requirements, the network operators’ strategy and manufacturer solutions. As a medium voltage technology specialist, Horstmann GmbH offers a great deal of experience, custom-fit products and individual solutions for substation digitalisation.
The grid is changing
For some years now, technology in the medium voltage grid has been increasingly going in the direction of digitalisation. The reason for this being the increasing demands and the new possibilities. In the past, electricity grids were usually planned centrally and operated with a constant load flow direction from high to medium to low voltage. Today, increasingly complex distribution grids with decentralised feed-in points and changing load flow directions prevail. Among other things, wind and solar farms and the charging infrastructure for e-mobility as well as heat pumps, battery storage and electric vehicles in private households have to be integrated.
Can smart grids replace experience?
For many years, it was relatively easy for experienced control centre teams to keep track of the grid. With today’s complex grids, this is much more difficult. In this context, the fluctuating feed-in of sustainably generated energy contrasts with increasing requirements for an uninterruptible power supply for end customers. This is a dilemma that requires more grid transparency and can only be solved in the long term by more and better sensor technology in the depth of the grid. In addition, innovative algorithms and artificial intelligence (AI) increasingly have to be integrated at the control centre.
Flexible solutions from the inventor of the short-circuit indicator
Horstmann is an experienced specialist in the field of medium voltage. Its range of services spans from retrofittable measurement sensors to solutions for the evaluation and processing of measurement data if a fault occurs and during normal grid operation. Our own telecommunication solutions allow substation information to be transmitted to the control room. The data concentrator and the iHost visualisation interface give distribution grid operators a mini-SCADA system as an alternative to the traditional control room system.
Digitalisation needs data
To digitalise grids, it is first necessary to have sufficiently high-precision measured values for the condition of the grid and the electrical equipment installed in it. The respective ‘network health’ status can be reliably ascertained with a precise measurement. In addition, the reciprocal influences of feed-in and reference can be determined in order to subsequently develop solutions that prevent any potential problems from arising. Increased transparency can increase grid stability, reduce downtime and improve overall grid efficiency.
Does digitalisation in medium voltage systems pay off?
Digitalisation requires investment. Depending on the condition of the grid and the digitalisation goals, retrofit measures, i.e. overhauling a system by replacing individual components, can make sense. Intelligent systems allow network operators to significantly reduce service and repair costs. Thus, the use of a fault direction indicator shortens the often time-consuming search and SAIDI values. This helps to prevent the threat of penalties and justifies grid fees. In addition, measured values provide the data basis for predictive maintenance measures. This allows failures to be prevented or controlled in such a way that facilitates the optimised deployment of the service team. Depending on the performance of control room software, smart grids also offer almost unlimited possibilities for optimising grid use, increasing grid efficiency and covering spontaneous and regular power peaks. This sustainably improves economic efficiency and contributes to the achievement of climate targets set by companies, but also those that fall within the framework of the European Green Deal.
How grids become digital
In European medium voltage grids, two functional features are currently crystallising in digitalisation: on the cable network side, mainly traditional short-circuit and earth-fault direction indicators, including those with Modbus communication, are used for simple load flow monitoring. Depending on the requirements, these can be additionally supplemented with functions such as switching, temperature measurement and high-precision network monitoring as well as with modern communication protocols. In the overhead line network, in addition to the Navigator LM, Horstmann offers the Smart Navigator 2.0 short-circuit and earth fault indicator for overhead lines, which measures current and voltage, load flow direction and conductor cable temperature and transmits network faults or measured values to the control centre via the integrated modem.
High-precision sensors make networks intelligent
Only high-precision measuring sensors provide sufficiently precise measured values for current, voltage, phase angle, power and power factor, energy, load flow direction and frequency directly from the switchgear field and makes them available for transmission to the control room. It is possible to define certain limit values for all measurement data in order to provide alarms for the control room. In addition, the transformer or station temperature can also be monitored using a PT-100 sensor.
Digitalisation level in new and existing buildings
In new buildings, state-of-the-art measuring technology and short-circuit and earth fault indicators are being installed in medium voltage systems, but also increasingly in low voltage systems. In most cases, digitalisation steps take place as modernisation measures in existing networks. Because of their different equipment with gas, solid and air-insulated switchgears, it is important to develop a suitable concept in advance and define medium-term and long-term digitalisation goals. As Horstmann has been using high-precision measuring sensor technology in simple short-circuit indicators for years, it is easy to migrate to the most modern fault direction indicators with the existing sensor technology, which is a unique selling point.
What role does AI play?
If network digitalisation is to succeed, it is not enough to simply collect data. After transmission, it is stored and used for further analyses in the control centre. However, powerful software is needed to evaluate the information collected. Artificial intelligence is already being used today in normal operation and if faults arise. It helps to make the distribution grid transparent, reduce downtime in the event of a fault and offers automatic decision-making aids. Self-repairing networks go one step further. Here, trained algorithms make independent decisions on the measures to be taken.
Thoughtful UX design facilitates digitalisation
The success of digitalisation measures in medium voltage systems depends on many factors. Simple integration, clear parameterisation, intuitive control and supported commissioning determine whether the measures are accepted by operating staff. That’s why Horstmann has developed simple user support for its units, which differs significantly from the complex parameterisation of days gone by. The entire commissioning process is designed to be quick and easy. The user interface is always oriented towards users’ situational requirements and current information needs.
Critical infrastructure and data security
Changes in the medium voltage grid mean that requirements for data security are also changing. Cyber attacks, data loss or manipulation are serious threats that can cause great damage to network operators and end customers. That’s why data security is a high priority for distribution grid operators as part of a critical infrastructure. Horstmann also always has this in mind, especially when it comes to the transmission, processing and use of data. Horstmann helps to securely master the challenges of digitalisation by developing project-specific solutions that meet customers’ data protection requirements.
Every journey begins with the first step
As described, there is no way around the digitalisation of substations worldwide and there is no way back. Horstmann also develops custom-fit solutions for new and retrofit projects so that all network operators can take the path to digitalisation at their own pace, within budget and in a way that is aligned with their goals. The aim is to bring each and every station and network to the best possible level of digitalisation so that they generate sustainable added value for the network operator.