Low Cost High Precision Accuracy Energy Meter

Abstract

Today to be able to be competent in the market, the control over each and every minimal cost is required. In the industries, the electricity consumption charges is one of the huge expense and it takes away a high percentage of revenues. Most of the machines nowadays run on electricity and their life span is very much dependent on the quality of power fed to it. So it is an immediate requirement of todays era to measure the power quantitatively as well as qualitatively. The system proposed here consists of an micro controller, a display and serial communication protocol (RS - 485) for the data to be viewed on laptop. The micro controller takes the line current and line voltage as an input in order to measure the power and energy and other parameters related to quality of power. First of all the intensity of current and voltage are converted in the range of the ADCs input by using voltage divider circuitry and Current Transformer. The energy is calculated by digitally integrating the instantaneous power with a delta time of about 1us. The on chip ADC is capable of simultaneously dual sampling, allowing current and voltage to be sampled together in each phase. We have tried to use the mechanical and electrical components that are available in our inventory to make it a low cost system. Intensive research was carried out while choosing components related to display, RS 485 section and micro controller section to make it available at lowest possible cost. The precision of the system plays role when the parameters are measured several times under robust conditions and it shows the same value. The system proposed here is in compliance with IEC standard IEC62052-11 and applicable for class 1S and class 0.5S.