Measurement of Reactive Volt- AMPERES
For the measurement of reactive power in a single-phase circuit we used compensated wattmeter. In compensated wattmeter the voltage applied to the pressure coil is 90° out of phase with the actual voltage and the wattmeter will read the reactive power VI cos(90° – Φ) i.e VI sinΦ.In single-phase measurement the filed of pressure coil lag behind by 90° when it measures actual power.
Single wattmeter method is used for power measurement in balanced three-phase circuit. The current coil of the wattmeter is inserted in one line and the pressure coil of it is connected across the other two lines.
The current flowing through the current coil of wattmeter is
The potential difference(pd) across the potential coil of wattmeter
Reactive power can also be determined from two wattmeter readings connected for measurement of power
Reactive power of load circuit, Q
- Measurement of Three Phase power:Three wattmeter method
- Two Wattmeter Method of Power Measurement
- Power factor
- Star and Delta connection
For more related terms in Electrical Engineering