Abstract: Frequency-domain impedance or admittance model is widely used for the harmonic stability analysis of the power electronic converters. Some researchers have independently developed some impedance models of the voltage-source converter in different coordinate frames, without showing their explicit relations. Other researchers have revealed partially the equivalence of the impedance models in the dq, PN and αβ coordinate frames recently, but this conclusions cannot be directly applied to the general coordinates because the transformation matrixes adopted by these researchers are constant ones or some erroneous derivations are found in these works. This paper systematically derives the overall admittance matrix models in the dq and "12" space vector reference frames and quantitively reveals the mechanism of negative conductance in the low-frequency ranges due to the phase-locked loop. Further, the frequency-domain relations of the commonly-used time-domain transformations, including Park, Clark, Lyon and Gu's transformations, are developed, based upon which the equivalences of the impedance models in the dq, fb, "12" coordinate frames are revealed. An impedance model in general coordinate frames is established, significantly improving the existing theory of the impedance stability modeling for the power electronic converters. A mirror-frequency-coupled 4-dimension admittance matrix in the αβ real coordinate frame is thus built for the first time. The effectiveness of the general model is verified by comparing the admittance models obtained from the theoretical derivation and the frequency-scan measurement.