SINGLE PHASE VOLTAGE DIGITAL PHASE LOCKING METHOD

摘要

The present invention relates to a single phase voltage digital phase locking method, and a preset level signal similar to a voltage signal to be measured is constructed. In the control process, according to an angular frequency obtained by the accumulation of an incremental angular frequency outputted by a PI controller and a reference angular frequency, a preset frequency is adjusted; the phase difference component of level vectors corresponding to two voltage signals is controlled to approach 0; and when the control is stable, the phase of the signal to be measured is tracked by an outputted phase angle, and a phase locking function is completed. According to the present invention, the current sampling point of the voltage signal to be measured and a previous (k-n)th sampling point are used to form level vectors. In the control process, only n sampling points are needed to be kept; when n is equal to 1, only the sampling values of one sampling period are needed to be kept. The storage space occupied is very small, the calculation is convenient and practical, and the method can be applied to product development.