METHOD OF CORRECTING MEASUREMENT RESULTS OF ELECTRICAL POWER QUANTITIES Russian patent published in 2010 - IPC G01R21/133 

FIELD: physics.

SUBSTANCE: measurement errors are reduced by taking stray inductance of the current sensor in calculations during each measurement cycle using auxiliary second winding of the current sensor. The current sensor has two insulated secondary windings - main and auxiliary. The main winding is loaded with periodically varying load with known resistance values. The auxiliary winding is not loaded. The output signal of the current sensor is measured using an analogue-to-digital converter. Measurement results of the phase difference between the input voltage signal and the input current signal are calculated for each resistance value of the load of the main winding, as well as any of the following quantities: electrical power, energy, current. These results are recorded as preliminary results. Measurements are taken at the output of the auxiliary winding at the same time or successively with measurements on the load of the main winding and values of the same quantities reduced to the main winding are also calculated. These results are recorded as auxiliary results. Further, for each resistance value of the load of the current sensor based on measurement results of the phase difference and known parametres of circuit elements of a specific device, taking into account auxiliary results, pairs of correction coefficients are calculated: for the modulus of the input current signal and for the phase of the same signal. These correction coefficients are taken into account when determining final measurement results of electrical power quantities.

EFFECT: increased accuracy of measuring electrical power quantities, taking into account effect of stray inductance of the current sensor.

1 dwg