Improving the Electric Load Calculation for Apartment Buildings Based on Their Specific Power Capacity

The revision of regulatory documents aimed at improving the design of urban power supply systems makes it relevant to scrutinize the currently used methods for calculating the electrical loads that determine the number and capacity of transformer substations, cross-sections of power supply cables, and the estimated capacity of the utility connection. The methodology used in designing a residential microdistrict power supply system is focused on how the total living space of apartment buildings is used. Its advantage lies in the simplicity of calculations, but the lack of adaptation to a decrease in the actual specific load per unit area with its growth plus an overestimated fixed standard value give an unreliable final result. To preserve the advantages of the method, it is proposed to adjust it toward bringing the results of calculating the total power consumed by apartment buildings from substation buses closer to the actual load values. The daily load schedules of apartment buildings of standard designs equipped with electric stoves in the range of 11–25 floors were monitored. Measurements were taken at input switchgears. The electricity consumption of apartments, electrical receivers of common house needs, and a relatively small commercial load of apartment buildings were recorded at half-hour intervals. Statistical processing of measurements has shown that apartment buildings of 11–18 floors and 19–25 floors can be united into a common cluster based on the maximum specific load. By combining the daily load schedules for different numbers of apartment buildings, the dependence of specific load values on the building total area has been constructed. It has been shown that the results of calculating the apartment building total load correspond to the results of its calculation based on the specific load (of apartments), taking into account the common house needs and commercial load.