Reactive power measurement circuit

In a three-phase symmetrical system, the three-phase voltages are completely symmetrical and the load impedances of each phase are exactly the same, so the currents of each phase are also completely symmetrical. At this time, you only need
to use a power meter to measure the active power P of one-phase load and then multiply it by 3 times. , then the total power of the three phases is obtained. That is,
    P=3PA=3Ur Iweosje
    In order to measure the three-phase reactive power, you can connect the current
coil of the power meter to any one phase circuit according to Figure 6-4, and connect the voltage coil circuit to the other two phases. On the power supply end, since
the line voltage between any two phases in a three-phase circuit is always
904% phase different from the third phase voltage in star connection. Therefore, the reading of the power meter at this time is
    W=UilisinIP.
In the formula, P is the impedance angle of the load, then the reactive power of the three-phase load