The impact of harmonic distortions on power grids is a major issue in contemporary power networks as a result of the extensive application of non-linear loads. The purpose of this article is to explore the problem of harmonic distortion in power grids and its impact on the elements of the power grid, such as cable lines and transformers. The Schaffner PQS software product was used in this study to model power grids. New techniques for modeling power grids and finding technical solutions that meet the IEEE 519-2014 standard were introduced. The study finds that harmonic distortion can lead to an additional heat load being placed on cable lines and reduces the power available to transformers, which can decrease their rated power. The application of modern software reduces the time and complexity of calculations, and the availability of software solutions for limiting harmonic distortion simplifies the creation of solutions that meet this standard. Using the methods presented in the study, engineering solutions can be improved, the reliability of electrical systems can be increased, and the loss of electrical energy can be reduced. This can enhance efficiency for design engineers and technical specialists involved in the operation of power grids.