Digital measurement of phase angles for fault tolerant systems

A practical method for measuring phase angles digitally is presented. The appropriate software methodology for extending the concept to similar applications is shown. It is shown that approximating Y = sin(X) near the zero-crossing as a straight line introduces little error, which will not significantly affect any further calculations. If there is a large number of samples per period of the sinusoidal, there will be even less error introduced by this approximation, since the samples around the zero-crossing will be even closer together. The phase angle measurement can be carried out in the field and the information can be used for system control and fault tolerance