Transducer Based on Current Transfer Ratio of Optocouplers to Smart Electricity Meters

Voltage and current sensors are the first keys in smart electricity meter design. They must meet accuracy, security, and reliability. Hence, these sensors become sophisticated and expensive. This paper proposes a transducer not only to meet charge electricity billing, but also to acquire waveforms to evaluate adverse power quality phenomena. The proposed transducer is based on an optocoupler to isolate the electrical network from the meter. The transducer design uses a suggested method to exploit properly the current transfer ratio to meet the accuracy and linearity needed in the power quality context. In addition, a method to estimate a correction factor to compensate for the tolerance in the component values of the transducer is given. The proposed transducer has been validated using Oread Lite® software to simulate different case studies related to power quality phenomena. Results show that the proposed transducer has an adequate performance for smart electricity meters that can be extended to evaluate adverse power quality phenomena.