IMPEDANCE DETECTION METHOD AND PHOTOVOLTAIC SYSTEM

An impedance detection method and a photovoltaic system are provided to help reduce complexity and costs of impedance detection. The method includes: sampling a voltage between a direct current bus and a protective earthing at each of a first time point and a second time point, to obtain a first voltage value and a second voltage value; sampling a leakage current on the direct current bus at each of the first time point and the second time point, to obtain a first current value and a second current value; and calculating an insulation impedance value of a combiner box based on a difference between the first voltage value and the second voltage value and a difference between the first current value and the second current value, to determine whether impedance of the combiner box is abnormal.