Arteche has presented the paper ‘Understanding the contribution of the noise to the error in LPIT (Low Power Instrument Transformer)’, during the High Voltage Equipment Session of the 2021 Cigre Canada Conference & Expo.
CIGRE Canada is the Canadian National Committee of the International Council on Large Electric Systems, the leading international organization on high-voltage electricity generation and transmission. This year’s conference is titled “Decentralization, Decarbonization & Climate Change Adaptation”.
The paper analyses the differences between the error behavior in electronic LPITs (more concretely in Optical Current Transformers) compared with the conventional instrument transformers.
A conventional current instrument transformer’s accuracy is mainly affected by core material, the current level (percentage of the nominal current) and the burden connected in the secondary. On the other hand the error in NCIT (non-conventional instrument transformers) such as the Optical Current Transformers (and in most of the electronic LPITs) is caused by the electronic noise added in the current calcullation process (from light to the digital values).
The aim is to provide a general view of the capabilities of the LPITs and introduce new factors when evaluating their accuracy depending on the application.