| 主权项 |
1. An electric power metering device, operable in first and second operating stages for measuring a primary current, or power in a primary electric conductor, said device comprising:
at least one current sensor for supplying a secondary measurement current representative of a primary current flowing in a primary electric conductor, an electronic measurement circuit and rectifier bridge, connected to said at least one current sensor for providing said secondary measurement current to the rectifier bridge, said rectifier bridge for converting the secondary measurement current to a rectified current; a processing circuit connected to the electronic measurement circuit and rectifier bridge; a transmitter connected to the processing circuit for transmitting messages over a wireless communication network to an electric power measurement receiver; an electric current integration capacitor connected to said at least one current sensor via the rectifier bridge, said electric current integration capacitor for, during a first operating stage of the device, integrating and accumulating the rectified current applied to the electric current integration capacitor from the rectifier bridge, to produce an electric voltage representative of the integration of the rectified current or electric power accumulated in the electric current integration capacitor; voltage threshold detection means connected to said integration capacitor for detecting overshoot of a predefined voltage threshold of said integration capacitor, said predefined voltage threshold being an amount of electric voltage representative of the integration of the rectified current or the electric power accumulated in the electric current integration capacitor, as determined during the first operating stage; switch means commanded by said threshold detection means, and for, during a second operating stage when the electric voltage on said electric current integration capacitor exceeds the predefined voltage threshold, supplying electric power accumulated in the electric current integration capacitor to said processing circuit and said transmitter, said processing circuit and said transmitter for then transmitting a power message representative of an amount of electric power or of electric current that has flowed in said primary electric conductor; and discharging means for discharging the electric current integration capacitor when the power message has been transmitted by said processing circuit, said transmitter thereby ending the second operating stage. |
