Because the mutual inductance of Rogowski coil is very small, the induced voltage is so feeble that it is very difficult to measure the small current accurately. So this paper adopted the new materials to make the high precise and mutual inductance Rogowski coil with new method.
The motor s physics process in the changing of magnetic store energy and mechanism and parameter calculation in the self inductance, mutual inductance, magnetic flux linkage and electromagnetism torque is discussed in such respect of multi return and electromagnetism torque theory.
Electromagnetics course mainly including basic phenomena and laws of electro- magnetics, electrostatic field in vacuum, in conductor and in electric medium, electric energy, stabilized current, stabilized magnetic field and its basic laws, electric and magnetic fields caused by a moving chager in lower speed, the transform of electric and magnetic fields between different systems of coordinates, inductive laws, eddy field, self inductance, mutual inductance and transient, molecule current and magnetic substance, ferromagnet, boundary conditions, magnetic circuit theorem, energy of magnetic field and density of magnetic energy, displacement current, Maxwell's equation, electromagnetic wave, Poynting vector.
