Electric meter comprising a power relay and method for monitoring the power relay of an electric meter
AssigneeSagemcom Energy & Telecom SAS
InventorsChristophe GRINCOURT, Marc JEANROT
Life of this patent
Estimating the term…
Abstract
In an electrical device connected between an electrical network and an electrical installation, for example an electricity meter, the monitoring method disclosed allows the value of the contact resistance of a power relay of the device to be estimated in real time. The method raises an alarm when resistance rises sharply. This allows real-time detection of abnormal heating of the power relay, which could, for example, lead to a fire. This also allows the electricity meter of an installation to be exonerated in the event of a fire.
Claims18
An electrical device configured to be mounted between an electrical network and an electrical installation, the electrical network delivering an electrical signal to one or more phases, the device comprising at least:
- for each phase, a current sensor mounted in series with a power relay and intended to measure a current flowing in the power relay when it is closed, the current sensor being intended to be connected to the electrical network at an upstream point and the power relay being intended to be connected to the installation at a downstream point,
- for each phase, a first voltage sensor mounted at the upstream point to measure an upstream voltage,
- for each phase, a second voltage sensor mounted at the downstream point to measure a downstream voltage,
- at least one analog-to-digital converter, configured to obtain, for each phase, at a plurality of measurement times over one or more measurement periods, samples of the upstream voltage, the downstream voltage and the current,
- a processor assembly configured to determine, for each phase, from the samples obtained, magnitudes the ratio of which is representative of a resistance value of the power relay, and to generate an alert based on the ratio obtained, and
- a modem to transmit the alert.
A method for monitoring an electrical device configured to be mounted between an electrical network and an installation, the electrical network delivering an electrical signal to one or more phases, the device comprising at least:
- for each phase, a current sensor mounted in series with a power relay and intended to measure a current flowing in the power relay when it is closed, the current sensor being intended to be connected to the electrical network at an upstream point and the power relay being intended to be connected to the installation at a downstream point,
- for each phase, a first voltage sensor mounted at the upstream point to measure an upstream voltage,
- for each phase, a second voltage sensor mounted at the downstream point to measure a downstream voltage,
- at least one analog-to-digital converter, configured to obtain, for each phase, at a plurality of measurement times over one or more measurement periods, samples of the upstream voltage, the downstream voltage and the current,
- a transmission modem,
- the monitoring method comprising:
- determining, for each phase, from the samples obtained, magnitudes the ratio of which is representative of a resistance value of the power relay for the measurement period,
- generating an alert based on the ratio obtained, and
- transmitting an alert via the transmission modem.
Dependencies are inferred from the claim text.