Improvement of Power Quality in Power Transformers Using the Enhanced DQ Method

Power transformers are critical components of power system, adversely affected by harmonic distortions. This effect leads to increased heat losses, insulation stress, diminished insulation lifespan, and a reduction in both efficiency and power factor. The durability of distribution transformers significantly depends on the quality of power within the networks. There is a persistent need for harmonic reducing filters equipped with robust control techniques to diminish the adverse effects of harmonics on transformers. Traditional approaches utilize the dynamic reference frame (DQ) method to manage the shunt active power filter (SAPF) for harmonic mitigation. However, this conventional DQ control exhibits limitations, including slow response times and delayed operation in abnormal grid conditions. To address these issues, this research proposes an enhanced DQ method that focuses on the accurate detection of positive and negative sequence components, thereby enabling precise control of the SAPF for the transformer's dependable functionality. This novel detection technique significantly quickens response times, mitigates the impact of harmonics on transformer operations, and enhances the overall power factor. Through rigorous evaluation under various abnormal operating conditions and comparison with the conventional DQ control method, our analysis highlights the superior performance of the enhanced DQ control method in improving power transformer efficiency.