PCIM: LEM current transducer steps up in accuracy
- Author:Ella Cai
- Release on:2017-05-17
LEM has unveiled at PCIM in Nuremberg a new design of current transducer which is notable for its high accuracy and low noise for non-intrusive and isolated measurement of DC, AC and pulsed nominal current of 2000A.
The 2000-S model transducer also has an extended operating temperature range of -40 to +85°C.
Specified accuracy with linearity and low offset over temperature range is better than 3 ppm and 10 ppm respectively.
The firm has incorporated digital signal processing and come up with a new design of its fluxgate architecture for the ripple cancellation of the fluxgate drive frequency.
As a result the transducer maintains its accuracy over a wider temperature range, with reduced noise level compared with the previous generation.
After calibration, the remaining peak-to-peak ripple is less than 50 ppm, relative to the full scale transducer output, over the full operating temperature range.
Allowing signal processing to be done in the digital domain means a complete immunity to temperature effects, interference and supply voltage variation after the ADC. In particular, offset and offset drift have been improved.
The DSP has also been used to reduce the interference or ripple from the fluxgate driving signal at a fixed frequency. According to LEM, this results in higher frequency harmonics reduction.
The remaining interference has been eliminated by driving a ‘ripple compensation coil’ whose amplitude and phase are adjusted during the calibration of each transducer.
The 2000-S model transducer also has an extended operating temperature range of -40 to +85°C.
Specified accuracy with linearity and low offset over temperature range is better than 3 ppm and 10 ppm respectively.
The firm has incorporated digital signal processing and come up with a new design of its fluxgate architecture for the ripple cancellation of the fluxgate drive frequency.
As a result the transducer maintains its accuracy over a wider temperature range, with reduced noise level compared with the previous generation.
After calibration, the remaining peak-to-peak ripple is less than 50 ppm, relative to the full scale transducer output, over the full operating temperature range.
Allowing signal processing to be done in the digital domain means a complete immunity to temperature effects, interference and supply voltage variation after the ADC. In particular, offset and offset drift have been improved.
The DSP has also been used to reduce the interference or ripple from the fluxgate driving signal at a fixed frequency. According to LEM, this results in higher frequency harmonics reduction.
The remaining interference has been eliminated by driving a ‘ripple compensation coil’ whose amplitude and phase are adjusted during the calibration of each transducer.
