ALECTRICAL ENERGY METERING DEVICE AND METHOD BY USING SAMPLING RESISTORS IN THE WHOLE CURRENT LOOP

摘要

The present invention relates to an electrical energy metering device and its method for measuring electrical energy. The device and the measuring method characterised in that every phase lines and zero line of the electrical energy metering device are connected in series with metallic sampling resistors, and the voltage varying signals from various metallic sampling resistors are supplied to the sampling signal processing units which separated from each other in order to make pretreatment. Every separated sampling signal processing units are supplied with their respective power sources that are independent of each other. Then, every signals pretreated by their corresponding signal processing units are supplied to the same measuring signal processing unit in order to do compare and judgement. In the end, the measured value which approaches to the actual energy consumption can be obtained. The present invention can realize the complete measurement of actual electrical energy consumption indeed. Moreover, the metering device's ability to avoid the alternating magnetic field interference is improved markedly.