An algorithm for instantaneous real power and reactive power as well as instantaneous apparent impedance at mechine terminals in a balanced three phase system has been obtained after the relationships between the instantaneous power, voltage and current in dqo system is converted into those in abc system by Park equations.

The concept of apparent impedance of controlled source and the apparent impedance method for electronic circuit analysis are introduced in this paper.

Measurement of apparent resistivity value for coal slices of different seam structures;

1-D Simulation on model apparent resistivity curve of CSAMT method in certain mine;

Definition of whole zone apparent resistivity for transient electromagnetic method of current dipole source;