This paper analyses errors associated with the analogue-to-digital conversion process of a digital signal processing unit (DSP) within the operation of an Optical Current Transducer (OCT). Quantisation of the analogue current measurement signal leads to measurement errors which are a direct consequence of the uncertainty with which an N-bit resolution analogue-to-digital converter assigns a binary word for a given analogue 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 analogue-to-digital 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.
['P. Niewczas', 'A. Cruden', 'W.C. Michie', 'W.I. Madden', 'J.R. McDonald']
Error analysis of an optical current transducer operating with a digital signal processing system