According to the load graph of motor under variable load, this paper introduces some ways to select motor power through calculating the equivalent electric current when the calorific capacities of motor at each short-term interval are equal.

On the basis of equivalent current method, this paper deduces the fomulas for calculating starting torque and quality factor of capacitor start single phase motors in which the main winding and the auxiliary winding are displaced by any space angle.

According to a special cross-country fault occurs on certain 220 kV transmission lines,this paper calculates the fault components of current and voltage and analyzes the performance of line protection based on the method of equivalent current and sequence component.

Based on the equivalent current method,the operation performance of the motor is studied and the symmetrical operation condition is set up.

Analytical expression of equivalent currents on stratified anisotropic material backed by metal surface;

A rapid evaluation formula for the PO method on electromagnetic scattering by arbitrary shaped conducting targets with partial coating is obtained by approximating electrically large scale objects with polygons, based on the theory of equivalent currents on the arbitrary RAM surface with the infinite metal substrate.

In this paper, high frequency scattering theories, including physical optics (PO), geometrical optics (GO) and equivalent currents (MEC), were used to calculate the radar cross section of winged missiles with three typical warheads (ellipsoidal, olivary and hemispherical warheads) considering the phase contributions of scattering centers.

Based on introducing the mathematical principles, time spectrum characteristics and equivalent electric current ring properties of several typical models, the author has put forward a technique for rapid interpretation of data obtained by the transient electromagnetic method.