Analysis of Harmonic Characteristics and Filter Application for Harmonic Mitigation in Detached Houses

Recently, electrical equipment in detached houses include various power conversion devices such as LED lighting, HVAC systems, electric vehicle chargers, and photovoltaic (PV) systems. This study systematically analyzed the harmonic characteristics of major electrical appliances used in detached houses and verified the effectiveness of filter application for harmonic mitigation based on measurement data at the main circuit breaker. The results of individual measurements of major appliances showed that the voltage total harmonic distortion (V_THD) satisfied the IEEE 519 standard (≤8%). However, the current total harmonic distortion (I_THD ) and current total demand distortion (I_TDD) exhibited relatively high values in appliances such as refrigerators and HVAC systems, and the I_TDD measured at the main circuit breaker ranged from 23% to 29%, exceeding the IEEE standard limit of 15%. To resolve this issue, the passive low-pass Bessel filters were designed and fabricated. Measurement results indicated that V_THD was reduced by approximately 12% 16%, and I_TDD was reduced by up to 47%. In particular, during periods without PV generation, the I_TDD decreased to below 15%, satisfying the standard, and power factor improvement was also confirmed. This study empirically identified harmonic problems occurring in detached houses and demonstrated that cost-effective passive filters can serve as an effective solution.