A test system and test method for static watthour meters for immunity to HF electromagnetic fields

In Japan, testing of the immunity of static watthour meters to HF electromagnetic fields as part of the type approval test is conducted in accordance with IEC Publication 801-3. The authors have constructed a test system to check such immunity. This system uses a log periodic antenna and biconical antenna and checks the said immunity to electromagnetic field strength of upto 10 V/m with a HF range between 80 MHz and 1 GHz in an anechoic chamber. In addition, the use of a TEM cell enables a similar test for the range between 1.5 MHz and 240 MHz with a field strength of upto 80 V/m. The immunity test consists of the following two components. (1) Observation of any change in the display on the static watthour meter subject to electromagnetic radiation when only rated voltage is supplied to the voltage circuit of the said meter. (2) Observation of any change in error of the static watthour meter subject to electromagnetic radiation when rated voltage and current are supplied to the voltage circuit and current circuit respectively of the said meter. The present report describes the evaluation method for the field uniformity inside the anechoic chamber, the immunity test system and the test method developed by the authors