Distorted wave alternating current characteristic measurement equipment

摘要

PURPOSE:To easily measure the characteristic value of a distorted wave alternating current with high accuracy by generating a synchronizing signal synchronized with cycles of the basic wave component of the distorted wave alternating current and setting a sampling time corresponding to an integral multiple of cycles of the synchronizing signal. CONSTITUTION:A synchronizing signal generating circuit 10 generates the synchronizing signal 11 synchronized with the basic wave component of the distorted wave alternating current containing the basic wave component and higher harmonic components. This synchronizing signal is supplied to a cycle setting circuit 12 to set the sampling time corresponding to the integral multiple of cycles of the synchronizing signal. Sample holding circuits 18a and 18b samples plural instantaneous values of the distorted wave alternating current within the sampling period at cycle intervals shorter than the cycles of basic wave. Those sampling data are A/D converted by 12-bit ADCs 15a and 15b from analog to digital and a microprocessor 8 computes the characteristic value of the distorted wave alternating current from those data.