During the line parameter measurement test, assuming the amplitude of the 50Hz power frequency current signal in the test loop is I_interference, and the amplitude of the frequency-shifted measurement current signal of the instrument is I_test, the instrument meets the measurement accuracy requirements within the measurement range under the condition that I_interference/I_test < 2.
In the power frequency parameter measurement test of high-voltage transmission lines, power frequency interference is a key factor affecting the parameter measurement test. In order to avoid the influence of power frequency interference on the measurement results, conventional measurement methods often require a test power supply with larger power to improve measurement accuracy. This instrument adopts frequency-shifting technology and uses a frequency-shifted power signal to measure the relevant parameters of the transmission line. Compared with conventional methods, the instrument has obvious advantages in size and weight, and has excellent anti-interference performance. When the interference current is twice the test current, it can still ensure measurement accuracy.
