Nowadays, the topic of harmonics is one of the crucial subjects in assessing the power quality of electrical networks. Harmonics are recognized as the most significant power quality disturbance in the network. Non-linear loads and distributed generation sources, such as inverter-based solar cells, which play an undeniable role in distribution networks with the advancement of renewable energies, cause the expansion of network harmonics. Identifying voltage and current harmonic distortions and determining the sources of voltage imbalance are among the most critical challenges in power systems. Today, the evaluation of power quality has gained increasing importance mainly due to the widespread use of non-linear electronic devices and variable non-linear loads in network equipment and on the consumer side. Therefore, determining the factor causing harmonic disturbance and its contribution to this disturbance is necessary. In this paper, firstly, the harmonic model of specified loads is developed, and subsequently, the harmonic contribution of the load and the network at the common coupling point is determined through the measurement of current and voltage at the load-network connection point.
