The Signal Conditioning

      v0 and v1 fed into the Signal_Conditioning block to have normalized so that the maximum voltage is Vpp = 5V. In this block, we add 2.5 V DC offset voltage to both signal so they have a voltage range of 0 to 5 V according to the ADC limits.
      The phase shift will occur while converting grid voltage to low voltage and converting current to voltage. To compensate them, on the block Signal_Conditioning, there is the phase shifting circuit that will adjust the phase again. This circuit also functions as a first-orde high-pass-filter. These filters are used to reduce the amplitude values of harmonic components which might make the calculation value of the frequency and phase difference to be wrong.
     The output of this block is a voltage signal v0' that it’s shape like the grid voltage, and voltage signals v1' it’s shape like the current grid. Phase shift between v0' and v1' equal to the phase shift between voltage and current grid.

The Need for Phase Difference Measuring Instrument
Measure the Frequency of Grid Voltage rather than Measure the Frequency of Current
Voltage and Current Converter

The use of the microcontroller ADC
Frequency Measurement
Phase Difference Measurement
Output Display Format