A power conversion apparatus , comprising a power conversion circuit , an impedance adjustable circuit , and a control circuit , wherein the control circuit is connected to both the power conversion circuit and the impedance adjustable circuit , an input end of the power conversion circuit is configured to connect to a power source, and an output end of the power conversion circuit is connected to the impedance adjustable circuit ; the power conversion circuit is configured to adjust output power of the power conversion circuit under the control of the control circuit ; the impedance adjustable circuit is configured to adjust an output impedance of the impedance adjustable circuit under the control of the control circuit ; and the control circuit is configured to: when a working status of the power conversion apparatus is faulty, control the impedance adjustable circuit to adjust the output impedance of the power conversion apparatus to a first impedance, or when the working status of the power conversion apparatus is normal, control the impedance adjustable circuit to adjust the output impedance of the power conversion apparatus to a second impedance, wherein the first impedance is not equal to the second impedance; and wherein the working status of the power conversion apparatus is represented by the output impedance, and the output impedance of the power conversion apparatus when the power conversion apparatus normally works and the working status is normal is different from the output impedance of the power conversion apparatus when the power conversion apparatus is faulty and the working status is faulty; the impedance adjustable circuit comprises a first switch (K1) and a first load circuit , the first load circuit being serially connected to the output of the power conversion circuit , the first switch (K1) being connected in parallel to the first load circuit , and the first switch (K1) being further connected to the control circuit . the power conversion circuit is configured to adjust output power of the power conversion circuit under the control of the control circuit ; the impedance adjustable circuit is configured to adjust an output impedance of the impedance adjustable circuit under the control of the control circuit ; and the control circuit is configured to: when a working status of the power conversion apparatus is faulty, control the impedance adjustable circuit to adjust the output impedance of the power conversion apparatus to a first impedance, or when the working status of the power conversion apparatus is normal, control the impedance adjustable circuit to adjust the output impedance of the power conversion apparatus to a second impedance, wherein the first impedance is not equal to the second impedance; and wherein the working status of the power conversion apparatus is represented by the output impedance, and the output impedance of the power conversion apparatus when the power conversion apparatus normally works and the working status is normal is different from the output impedance of the power conversion apparatus when the power conversion apparatus is faulty and the working status is faulty; the impedance adjustable circuit comprises a first switch (K1) and a first load circuit , the first load circuit being serially connected to the output of the power conversion circuit , the first switch (K1) being connected in parallel to the first load circuit , and the first switch (K1) being further connected to the control circuit . <EOS>