Monitoring an electric power grid

Abstract

A method of estimating short-circuit current at a given bus of an electric power grid comprising at least one transmission system and at least one active distribution grid which includes power generators and power consuming loads. The method comprises: estimating (400) initial values and proportion for currents due to demand and production based on available, statistical information; refining estimates for the proportion of current due to demand and production using real-time measurement (404) of voltage and current of the given bus; and upon detection (406) of a voltage change event, estimating the short circuit current, short circuit capacity or short circuit ratio of the given bus and / or the local network based on the measured change in voltage and current. The statistical information may be historical data, weather data and type or capacity of generation in the active distribution grid. The method may also estimate the share of motor-based, inverter-connected and static loads before and after the voltage change.

Images