Patent ID: 8005637
Filing Date: 2011-08-23
Classification: G01R

Abstract:
1. An arrangement to determine at least one electrical feature of at least one electrical device, the arrangement comprising: a signal injection unit configured to inject a first test signal at a first main frequency into a first electric circuit, and to inject a second test signal at a second main frequency into the first electric circuit or into a second electric circuit, a signal conversion unit configured to measure a first and a second electrical quantity in the first electrical circuit resulting from the first test signal, and to measure the first and second electrical quantity in the first or second electric circuit resulting from the second test signal, a processing device including at least two analogue input channels configured to receive said measured electrical quantities and to determine said at least one electrical feature based on the measured electrical quantities, and a mixing unit, the mixing unit being configured to add the measurements of the first electrical quantity resulting from the first and second test signals and based thereon generate a first mixed signal, the mixing unit being configured to add the measurements of the second electrical quantity resulting from the first and second test signals and based thereon generate a second mixed signal, and the mixing unit being configured to supply the first mixed signal to a first analogue input channel of the processing device and to supply the second mixed signal to a second analogue input channel of the processing device, and wherein the processing device is configured to decompose the mixed signals to obtain the measurements of the first and second electrical quantities.