Voltage-Led Load Management in Whole Distribution Networks

The ability to manage loads can play a significant role in the future operation and planning of electricity networks. One way of unlocking this source of flexibility without directly involving thousands or millions of customers is to exploit the positive correlation between supplied voltage and demand, i.e., voltage-led load management. Distribution network operators, in particular, could achieve this by adequately controlling voltage regulation devices. Nonetheless, to quantify this it is key to understand the extent to which voltages can be changed (reduced) while considering the dependencies across different voltage levels. A methodology is proposed here to quantify the aggregated demand reduction unlocked by controlling primary substations considering the voltage interactions and constraints throughout the whole distribution network. Given the complexity and dimensions, the influence of the upstream network on primary substations and the effects on low voltage customers are analyzed separately whilst maintaining their dependencies. The methodology, developed within the largest UK load management trial, is applied to real 132 to 0.4 kV distribution networks adopting realistic load models. Results demonstrate not only the significance of the scheme as a source of flexibility but, crucially, that the interactions and constraints across voltage levels are key in its adequate time-varying quantification.