State Estimation in Low Voltage Grids Based on Smart Meter Data and Photovoltaic-feed-in-forecast

The integration of distributed generation causes an increase of the voltage magnitude in low voltage grids. In addition to classical grid expansion distribution system operators have various options at their hands to reduce the voltage rise, e.g. by installing distribution transformers with on-load tap changers or voltage regulators. But for efficient control the network operators need information on relevant operational system parameters. The classical approach of using measurement and monitoring devices from SCADA systems is comparatively too expensive and complicated. In future, smart meters can provide information about relevant operational data, which enables the identification of the system state in meshed low voltage grids. This paper proposes an algorithm for linear LV state estimation based on smart meter data and photovoltaic feed-in predictions. The results gathered from simulations and a field test are promising, especially due to a special approach resulting in a relatively high measurement redundancy which is not common for state estimation in LV grids.