The present specification relates to a data collection apparatus of a power system, the data collection apparatus comprising: a communication unit that communicates with a plurality of sites using different communication protocols to receive, from the plurality of sites, data about energy use information; a storage unit that stores a plurality of data models respectively corresponding to the communication protocols to store the data in each of the plurality of data models; and a processing unit that generates a basic data model by performing data modeling according to any one of the communication protocols, generates one or more extended data models by performing data modeling according to the rest of the communication protocols, includes the extended data models in the basic data model, and stores the included extended data models in the storage unit.