What are the methods in measuring three phasa power in one wattmeter method?

In the one wattmeter method for measuring three-phase power, a single wattmeter is used alongside a phase shift technique, typically in a balanced load scenario. The power is measured in one phase, and the total three-phase power is calculated by multiplying the wattmeter reading by a factor that accounts for the phase voltage and current relationships. For a balanced load, this factor is often 3, as the total power is the sum of the power in all three phases. Additionally, the method can be adapted for unbalanced loads by using appropriate phase angle adjustments.