| 摘要 |
Method of determining the presence of an electrical supply network of IT type for supplying an automobile battery charger and corresponding charger. Method of determining the presence of an electrical supply network (4) comprising a permanent isolation controller and an isolation transformer connected upstream of an automobile battery charger (5), said charger being furnished with a device for estimating the quality of the earth by measuring the frequency of the network and the neutral-earth voltage, the battery charger (5) furthermore comprising safety mechanisms preventing the charging of the battery as a function of the comparison of the measurement of the neutral-earth voltage with a threshold value. The method comprises the following steps: there is carried out a comb filtering of the neutral-earth voltage measured by the battery charger (5) as a function of a measurement of the frequency of the network, then there is carried out a high-pass filtering, then there is determined the absolute value of the filtered signal, then there is applied a filter with variable dynamic range to the absolute value of the filtered signal, and thereafter it is determined whether the signal obtained on completion of the variable-dynamic range filtering is greater than a threshold value. |
