Dynamic Operating Envelopes in Distribution Networks: A Reliable Computation

The integration of energy-intensive resources at distribution level poses challenges on the operation of the distribution networks, which until recently were designed to be passive. This raises the need for new mechanisms, regulations and market designs that will ensure the safe operation of distribution networks under the integration of these new resources. Dynamic operating envelopes (DOEs) are explored as a solution to address this challenge. They ensure the distribution network operates within the limits of its physical capacity by setting a cap on the import/export power at every given time interval on the connection points. This paper proposes a method to compute DOEs in a multi-phase unbalanced distribution network accounting for transformer rating, voltage and thermal constraints with uncertain network inflexible loading. The problem is formulated as a chance-constrained model that is cast as a linear model after the relaxation of the uncertain parameters and the usage of an approximate linear model for multi-phase distribution networks. The method was tested on a the European low-voltage (EULV) network with 55 load nodes. The results demonstrate the promise of the method and the accuracy of the approximate linear model was verified by running a non-linear Zbus power flow.