Maintenance and renewal planning of equipment in power grids is mostly based on empirical values, expert knowledge or statistics. The data basis required for this is acquired in regular (e.g. every 4 years) on-site inspections of the equipment by the network operators' maintenance personnel. These approaches are already reaching their limits today due to a mostly insufficient database.
Measurement and diagnostic systems for monitoring the condition of equipment could close this gap. Embedded in existing asset management strategies, data analysis of online and permanently recorded condition data of the entire equipment fleet would open up completely new business processes, methods and strategies for network operators. A prerequisite for the implementation of such approaches, however, are low-cost technological solutions tailored to the application of the distribution network level. These include many sub disciplines, such as measurement and diagnostic technology, sensors and data processing, ICT, data storage or algorithms and condition assessment.
This is precisely where the MAKSIM project comes in. Based on MEMS technologies, the project partners Fraunhofer FIT, Maschinenfabrik Reinhausen GmbH, Robert Bosch GmbH and RWTH Aachen University are developing, applying and verifying low-cost sensor, measurement, information and communication technologies.
Measurement and diagnostic procedures that enable permanent online monitoring of central equipment in an electricity network are currently only used for equipment at the high voltage level (>= 110 kV). The much more compact and cost-effective equipment of the medium and low voltage level (< 30 kV) used in the distribution network is usually not monitored at all or only in a rudimentary way. A simple adaptation of standard measuring methods is not possible in view of the financial expenses for the measuring systems. Standard measurement systems from the high voltage level often cost as much as the operating equipment in the medium and low voltage level itself. However, sensor systems are known from other industrial sectors that show promising economies of scale due to very high quantities. For example, low-cost micro-electromechanical systems (MEMS) are used in the automotive, consumer or process industries, which contain integrated signal processing and communication interfaces in addition to sensors.
In cooperation with manufacturers (Fritz Driescher KG) and three distribution network operators from the regions of Aachen (RegioNetz), Cologne (Rheinische NETZGesellschaft) and Nuremberg (Main-Donau Netzgesellschaft), the first step is to define basic requirements for the necessary measurement and communication technology with regard to maintenance and renewal in the distribution network. Factors such as key parameters, sensors, measurement accuracy, reproducibility, availability, security, installation effort and marginal costs will be considered.
Based on this, bottom-up measurement procedures will be redeveloped within the framework of laboratory tests. In particular, it will be investigated how and whether low-cost sensors from other industrial sectors can be used. Another focus is on the implementation of a low-cost ICT infrastructure and the development of data processing and analysis procedures. Algorithms evaluate the condition of equipment or the plant fleet and transfer the result of the condition assessment to an asset management system of the end user. Different data analysis methods, correlation-based but also self-learning methods, are to be realized and analyzed with respect to their applicability on data collected by means of the tested low-cost technology. In order to integrate the results of the data analysis methods into the asset management of the end user, interfaces and visualization solutions will be developed.
Funding: Bundesministerium für Wirtschaft und Klimaschutz