A semantic model of events for integrating photovoltaic monitoring data

Solar plants typically consist of several thousands of passive photovoltaic modules that are connected via thousands of string boxes to hundreds of inverters. In addition, a solar plant has meteo-sensors, power meters and control switches. All these components continuously generate data that is collected by monitoring systems or SCADA systems on-site. From there onwards, this data is pushed to remote analysis servers. The optimal exploitation of this data is hampered by a lack of harmonisation and standardisation in the photovoltaic domain. The data-generating components originate from several different manufacturers, models and versions, and their output is thus not easily commensurable. Crucial for this paper is the fact that conceptually identical failure events are not logged with the same identifying labels. Therefore, every analysis of monitoring system data coming from photovoltaic plants needs an initial integration step to resolve this labeling issue. Our proposal is to facilitate the integration with semantic modelling by means of creating a photovoltaic event ontology with an SWRL reasoning layer.