The energy transition and the associated increase in performance require the smartification of the low voltage grids. Sufficient observability must be achieved in order to carry out the necessary grid expansion in a targeted manner and to enable operation with flexibilities in the future. The objective of the study is to evaluate and define the strategy for equipping low voltage grids with sensors (smart devices such as iONS, iKVS, iMsys), taking into account the measurement requirements in the key issues paper, against the background of the upcoming BNetzA determination on controllable consumption devices.

The necessary degree of observability (accuracy of the state estimation) was determined in the previous study. Against the background of the ongoing BNetzA consultation procedure on controllable consumption facilities (§ 14a EnWG), it must be examined for the equipment variants described by the BNetzA (contain requirements regarding the use of IMSys real-time data and transformer measurement) whether these guarantee the necessary degree of observability in different grid situations, or whether the requirements for observability can also be fulfilled by more cost-effective equipment variants.

The use cases defined in the previous study form the basis for the assessment and evaluation of the equipment strategy. On this basis, simulations were carried out to examine the degree of observability achieved (quantified via the estimation error).  Essential findings were presented to the BNetzA for consideration in the further definition.

In this study, E-Bridge investigated a practical equipment strategy for low voltage grids with sensor technology (smart devices such as iONS, digiONS, iKVS, iMsys), which takes into account internal and external framework conditions, such as the GNDEW amendment and the ongoing 14a determination procedure.

The simulation results show a network-specific dependency of the remaining estimation errors with different equipment variants. A generally specified equipment variant will lead to an overestimation of the need for measurement technology in a large number of grids and thus to avoidable costs. In addition to the specification of two fixed equipment variants, the additional specification of an estimation error to be complied with would enable a demand-oriented equipment of networks and a reduction of the demand for measurement technology.

You can find the study results here (only German language): Veröffentlichung_Studienergebnisse

The flyer (only German language) on the control of the low-voltage grid according to § 14a EnWG is available here.

E-Bridge Consulting Berater - David Echternacht
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Prof. David Echternacht
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