A cikin karamin da ake da tsarin voltage da kuma current ba suka shafi duka, wannan irin karami ake kira reactive power. An fada formula yaɗuwa don yawan reactive power a cikin karamin
Yadda Ake Yadda Reactive Power & Varmeters
Yadda ake yadda reactive power ita ce muhimmanci saboda yana nuna yadda karamin take gane: reactive power mai yawa ta yi nasarar load power factor, zai iya sa lalacewar gwamnati. Varmeters (volt-ampere reactive meters) suna yadda reactive power kuma ana taimaka masu circuit phases:
Single Phase Varmeter: Wannan shi ne electrodynamometer wattmeter na farko da pressure coil (voltage lag current coil by 90°). Current coil ta da shiga load current, wanda yake da 90° phase difference from supply voltage.
Polyphase Varmeter: Don multi-phase circuits (babu bayanai a nan).
Rabobi na single phase varmeter an nuna a cikin rubutun.
Single Phase and Polyphase Varmeters
Single Phase Varmeter: Ana iya samu gabatarwa saboda harmonics ko frequency deviations from calibration conditions, zai iya haɗa aiki masu karfi.
Polyphase Varmeter: Ana yadda reactive power (da voltage-current phase displacement) ta haka ake amfani da phase-shifting transformer (two open-circuit transformers in open delta configuration). Current coils ta shiga series with the line; pressure coils ta link to the auto-transformers’ common terminals.
Varmeter Tappings and Three-Phase Reactive Power Measurement
Auto-Transformer Tappings in Varmeters: Auto-transformers suna da tappings at 57.7%, 100%, and 115.4% (maximum line voltage). Pressure coil of one wattmeter ta shiga 115.4% tapping, the other to 57.7%. Both coils produce voltages equal to line voltage but with a 90° phase shift; summing their readings gives total reactive power.
Balanced Three-Phase Circuits: Use the single wattmeter method: current coil in one phase, pressure coil across another phase to measure reactive power.
Bar da current through the current coil – I2 ，Voltage across the pressure coil – V13
Total reactive volt amperes of the circuit
The phase angle
