In this research work, a new approach to compensate for both the response In this paper, we highlight the crucial role of substation digitalization in identifying the origins of harmonic disturbances within iron and steel plants connected to the point of common coupling (PCC). Our method capitalizes on the benefits of a digital substation infrastructure by utilizing merging units that operate at a 28.8 kHz sampling rate, in line with the IEC 61850-9-2 standard. This setup allows for the real-time measurement of voltage and current from all feeders, streaming these high-resolution data directly to substation servers. This digital approach not only facilitates precise and timely data acquisition but also enhances the overall reliability and efficiency of the monitoring process. By digitalizing the substation, we enable a more dynamic response to power quality issues and improve the capacity for preventive maintenance. Integrating our method into existing digital substations supports a robust framework for managing and mitigating the effects of current harmonics and interharmonics, showcasing the practical benefits of advanced digital infrastructure in critical utility operations. We propose attention based long short-term memory as a novel method for determining the harmonic responsibility of each plant without the need for instantaneous impedance measurements. This method relies on the correlation of time-synchronized voltage and current measurements taken from all feeders at the PCC. The approach is first validated using synthetic data generated in a PSCAD/EMTDC simulation environment, as well as real-world field data. Further verification is conducted through measurements of voltage and current waveforms using mobile Power Quality (PQ) measurement systems at one of the PCCs in the electricity transmission system. Our results demonstrate that the harmonic responsibility of each IS plant can be accurately determined for each harmonic order. Unlike existing methods, our proposed approach eliminates the need for online system impedance measurements or in-plant measurements.