Research on Reactor Loss Monitoring System Based on On-line Energy Harvesting

Reactor often causes electrical safety incidents due to insulation problems, which seriously affects the safe and stable operation of power grid. The common characteristics of the above problems are reflected in the significant change of active power loss. The conventional on-line monitoring method cannot achieve stable and large power output within a wide range variation of transmission line current, which could easily cause power supply interruption. Therefore, a current transformer with open air gap is designed to realize resonance between the excitation inductance and matching capacitor on the secondary side of the magnetic core, which greatly increases the line impedance and restrains the line current to realize the steady-state DC power supply. In addition, due to the influence of power grid fluctuation and current harmonic, the loss difference between the maximum and minimum can reach 15% in actual measurement. Therefore, this paper constructs the three-phase voltage and current model based on the instantaneous reactive power theory. And Chebyshev-I third-order filtering algorithm is proposed to separate the DC disturbance. The calculation accuracy of active power loss can be accurate to 0.5%. Finally, the system is successfully connected to the power grid for monitoring, which proved the stability of operation and the accuracy of monitoring.