Measurement Techniques for Distribution Feeder Impedance by High Frequency Injections

The line impedance could be measured by means of only passive elements such as inductors or resistors, that is presented at first. However, as the voltage and current used for the measurement are increased, the size of the inductor or resistor being used also needs to be increased, so in practice it would be virtually impossible to make an accurate measurement. Because of this, we have developed a novel measurement method for feeder impedance using an inverter circuit, which we describe secondly. In the third place, we propose another feeder impedance measurement method. The novel method is that the high frequency wave with minimum voltage is injected into the distribution feeder system. By means of this method, the feeder capacitance and the feeder inductance can be measured. These proposals are confirmed by the simulation or experiment