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I used a current sensor to measure the current of one of the motor phase lines (Iphase or Iline?), and used a voltage sensor to measure the voltage between two motor phase lines (Vline-line).

With these two values, how do I calculate the electrical power of the BLDC motor? They all are AC, but I don't know if I should use the formula of power calculation for WYE connection or DELTA connection.

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I don't know if I should use the formula of power calculation for WYE connection or DELTA connection

If your motor is 3-phase then the load type (wye or delta) makes no difference if you use the "two wattmeter" method: -

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In other words W1 + W2 = power for both configurations.

I used a current sensor to measure the current of one of the motor phase line (Iphase or Iline?), and use a voltage sensor to measure the voltage between two motor phase lines (Vline-line). With these two values, how do I calculate the electrical power of the BLDC motor?

I think you will have difficulty using your method because it cannot account for the full device power. You can't even reliably scale-up the reading because, on many types of load at low power factors (less than 0.5), using the 2 wattmeter method can produce a negative power reading on one meter with the other power being positive. At exactly 0.5 power factor, one meter will read zero.

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