| 摘要 |
<p>Electronic electricity meter, comprising means (8) for evaluating the electrical energy consumed by a load, the evaluating means being adapted to evaluate the energy consumption from a signal indicative of voltage supplied to the load and a signal indicative of load current, said load current signal being produced by a current transformer (4). The meter further comprises storing means (9) storing one or more parameters indicative of the variation with primary current of the phase error or ratio error arising in the secondary current of a current transformer of a predetermined configuration, and the evaluating means is further adapted to process the load current signal so as to produce an adjusted value for the load current signal, said processing making use of said stored parameters. The parameters stored by the storing means (9) preferably comprise a plurality of values of phase error and/or ratio error for a respective plurality of primary current values of the current transformer of predetermined configuration, and the evaluating means is adapted to process the load current signal so as to produce an estimate of primary current in the current transformer, to select from the storing means (9) a value of phase error and/or ratio error for one of said plurality of primary current values corresponding to the estimated value of primary current and to adjust the load current signal using the selected value of phase and/or ratio error. <IMAGE></p> |
