Measurement of electricity consumption with compensation for nominal supply voltage variation

• Main Authors: RAY-I CHANG, CHING CHUANG, JI-TSONG SHIEH
• Format: Patent
• Language: English
• Published: 01.05.2013
• Subjects: MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

An electricity consumption measurement apparatus comprises a detector for measuring voltage and a processor to correct the calculated power consumption for variation of the voltage away from the nominal supply voltage. A voltage variation ratio, called the variation rate, is calculated by dividing the measured voltage value by a base voltage value, where the base voltage value is the rated supply voltage e.g. 110V. The processor adjusts the calculated electricity or power consumption value by multiplying it by the variation rate to compensate for deviation of the supply voltage away from its rated voltage value. This allows accurate power data to be obtained even if the voltage varies. The base voltage may also be an average voltage calculated over time rather than the nominal rated voltage. The method may be useful in identifying appliances drawing power from an electrical system, because supply voltage changes are compensated and do not affect the identification.