**Abstract**

The paper is concerned with the mathematical model developed in MATLAB SIMULINK, which is used to calculate electric power losses. . The developed model allows the calculation of load losses in the overhead and cable lines, transformers, standby losses, it also makes it possible to study the impact of various modes and network parameters on the loss amount. The model was used to calculate load losses, standby losses of transformers and lines of different voltage classes in different departments of the OJSC "MMK".

**Keywords**

Load power loss, standby losses, methods for determination of losses, mathematical model for calculating electric power losses.

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