A Detection Method for Detuned Components of DC Filters in UHVDC System Based on Harmonic Current and Harmonic Impedance Information

Detuning of DC filters in Ultra High Voltage Direct Current (UHVDC) system will increase the harmonic level. The positioning of detuning elements has important application value for improving the operation reliability of DC filters. At present, the fault research of high voltage capacitors has been more perfect, but the detection scheme for low voltage components is less. This paper proposes a method to locate low-voltage components by using harmonic current and harmonic impedance information. The method can locate the detuning elements by calculating harmonic current and harmonic impedance, and further calculate the variation of detuning elements according to the existing recording points in UHVDC transmission system. Finally, the effectiveness of the scheme is verified by simulation model.