POWER AND IMPEDANCE MEASUREMENT ON LINES
Forward and backward travelling wave.
The wave equations are partial differential equations (PDEs) of two variables t an d x and can b e solved by Laplace transform method. By taking Laplace transform of
and assuming zero initial condition s, the two PDEs become ordinary differential equations (O DEs) with respect to variable 
(with 
treated as a parameter):
Combining t hese two firs t order OD Es, we get t he voltage w ave equation as a second order ODE:
