Effectiveness of Local Voltage Management Services in Unbalanced LV Networks: A Techno-Economic Study

The voltage rise often associated with the proliferation of distributed energy resources (DER) compromises the integrity of low-voltage (LV) distribution networks. This paper develops state-of-the art modelling and optimisation techniques for unbalanced LV distribution to investigate the provision of different voltage management services (VMS) from these DER and their effectiveness in alleviating these issues. It is of particular interest to assess how such services align with the prevailing wholesale energy market conditions and different DER penetration levels. To that end, two different types of VMS are considered. The first consists of providing reactive power support by aggressive Volt-VAr control (VVC), whereas the second consists of a pricing mechanism for reactive power based on distribution locational marginal prices (DLMP). Assessment is performed considering different DER penetration levels and wholesale energy market conditions. The results illustrate that a base-case of PV and battery inverters providing VMS in the form of mandatory VVC, as defined by Australian Standard AS4777.2, is already beneficial in improving over-voltages. The paper then proceeds to show that (i) more aggressive VVC may further reduce voltage rise, and (ii) deploying the economic principles of wholesale markets to send price signals for active and reactive power provision unlocks additional revenue to customers and effectively addresses voltage issues.