Measurement of active power, electrical energy, and TRMS voltage and current using the dual slope conversion technique

We have exploited the dual slope (DS) conversion technique to realize an intelligent system with high resolution that ensures active power measurement and electrical energy consumption. The load power is suited by two Hall effect current and voltage transducers, which are associated upstream with a precision analogue multiplier. A DS analogue-to-digital converter (DS-ADC) performs the conversion by rejecting noise with a conversion time that is multiple frequencies of the ADC's first slope. The digital acquisition is made by a PIC 16F877 using a management algorithm ensuring the control, acquisition, and treatment of information. Results are displayed on a 2-line and 16-column LCD. The developed instrument is programmable, which gives it many advantages, such as speed of execution, measurement reliability, and error correction.