Division of Energy Systems and Energy Management (ESEM)


The rising, decentralized supply of electricity in the low-voltage distribution networks through photovoltaic systems, small wind power plants, cogeneration plants, etc. requires changes in the operation management of this network level. Due to the increase of renewable electricity producers, especially in rural areas, the low-voltage systems reach their limits. Without any measures, this results in violations of the permissible voltage limits and/or exceedances of the thermal load capability of the low-voltage lines. This results in shutdowns of PV systems or in the worst case triggering the NH-fuses.

With the help of smart distribution grids, by the integration of information and communication technologies, the costly expansion of these networks is either preventable, can be stretched or at least limited in time. Therefor new concepts for components and equipment with new technologies and procedures must be developed so that sustainable infrastructure solutions can be provided.

So far, a typical local area network was fed by a central transformer of the medium voltage level. The local network supplied exclusively consumers, whereby the direction and the height of the energy flow was easy to predict. Depending on the supply of PV systems, the transferred capacity is highly variable, the energy flow can return and even be greater than the flow to supply the loads.


As part of this project, a "Flexible Voltage and Active Power Controller for Low -Voltage Distribution Grids" (FLOW-R), has to be developed. It allows a locally selective voltage regulation and an operation in meshed low-voltage grids. Furthermore, it shall be possible to control the power distribution on every phase. The controllers have to be arranged reasonable in the network and connected through cross-linked control algorithms. This is addressed to the typical problems especially in rural area networks. It is essential that the solution is scalable and expandable to allow an economically transition from actual to target networks economically. The FLOW-Rs offer the opportunity through their mobility and ease of reuse elsewhere to perform a change of location, when the network requirements have changed.


The proposed project includes the scientific development of the new concept, the industrial implementation and testing of prototypical developed FLOW-Rs, as well as the business and economic cost-benefit analysis.

Therefor mathematical models for different network topologies are created and algorithms for network control are designed. In addition, the development of a communication concept for a local-autonomous network of FLOW-Rs occurs. For this purpose, a concept and building a security architecture to protect against unauthorized access are necessary. After the construction of the utilities and implementing the control algorithms, a laboratory and field testing is performed to verify the simulation and ensuring the function.

Publicly founded joint venture

”Flexible Voltage and Active Power Controller for Low -Voltage Distribution Grids” is a joint venture. It is funded as part of the 6th Energy Research program of the German Federal Ministry for Economic Affairs and Energy (BMWi). This program focuses on an environmental friendly, reliably and economic power supply. Next to the Chair for Energy Systems and Energy Management of the University of Kaiserslautern, the following partners are involved:

Pfalzwerke Netz AG
Walcher GmbH & Co. kg
Power Plus Communications AG
Pfalzwerke A

Person in charge

Dipl.-Ing. Stefan Lang

M. Sc. Haiyan Ma

Photo of project partners


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