| 摘要 |
The invention relates to a secure system (1) for charging the battery (3) of a motor vehicle from a power supply network (2), which system is placed on board a vehicle and comprises means (4) for measuring the frequency of the network (2), injection means (5) for injecting current pulses into the network (2), means (6) for measuring the voltage between the earth and the neutral of the network (2), an analog filter (7) for filtering the measured voltages at high frequencies, a digital filter (8) for filtering the analog-filtered voltages at low frequencies, and means (9) for determining the resistance between the earth and the neutral of the network (2) on the basis of the digitally filtered voltages and the amplitude of the current pulses. The digital filter (8) comprises a mean value filter which determines a mean value on the basis of N voltage measurements spaced apart by a time interval T +T/N, where T is the period of the network (2) determined by the means (4) for measuring the frequency of the network (2). |
