Digital power-factor measurement device and method thereof

The present invention is digital power factor measuring device and measuring method. The device includes voltage transformer for cut-in of voltage signal and current transformer for cut-in of current signal. The voltage signal via the voltage transformer is divided into two paths in the shaping circuit and fed to the digital amount input module for measuring the period and the rise edge of the voltage signal separately before being fed to the programmable computerized controller. The current signal via the current transformer and the shaping circuit is fed to the digital amount input module for measuring the rise edge of the current signal being fed to the programmable computerized controller. The programmable computerized controller is connected to the communication interface, has power factor measuring program stored in its memory unit, and completes sync signal period measurement, phase difference measurement and power factor calculation.