Error analysis of an optical current transducer operating with a digital signal processing system

This paper analyzes errors associated with the analog-to-digital (A/D) conversion process of a digital signal processing unit (DSP) within the operation of an optical current transducer (OCT). Quantization of the analog current measurement signal leads to measurement errors which are a direct consequence of the uncertainty with which an N-bit resolution A/D assigns a binary word for a given analog input value. This paper presents comprehensive simulations of the performance of different current sensors monitored by the DSP unit and discusses aspects of compatibility between the sensor dynamic range and the resolution of an A/D conversion process. Recommendations are given on how to match the OCT to the given A/D parameters, and vice versa, in order to meet specified accuracy requirements.