Microcontroller-based phase-angle measurement and correction technique

An intelligent system is presented, which monitors the phase angle continuously and in the event of the phase angle deviating beyond the allowable limits, a correction action is initialized to compensate for this difference by continuously changing a variable capacitor. Adjustment of the capacitance value is done automatically and the major advantage of the proposed system is its ability to continuously change the capacitance in a linear manner. Thus achieving high degree of accuracy in phase angle correction is feasible. The system has been implemented on an 8-bit microcontroller. Experimental results obtained show that the phase angle can be linearly varied over a wide range at different frequencies of the input signal.