DC-side impedance measurement method of voltage source converter based on secondary-side disturbance

The method of adding a disturbance power supply to the primary side has a relatively high cost of the disturbance power supply equipment, and the operation of adding a disturbance power supply to the primary side is more complicated. At the same time, due to the existence of the internal resistance of the power supply, the steady-state operating point of the original system will also be changed, which is not conducive to large-scale promotion in practical engineering. In this paper, a VSC DC-side impedance measurement method based on sampling point injection secondary-side disturbance is proposed, and PLECS simulation verification is carried out. In practical engineering measurement, the proposed impedance measurement method requires only a small capacitor in the main circuit, which can greatly reduce the cost of engineering measurement.