The errors in formulas for calculating the capacitance and the capacitive current by the “three non-power frequency current with equal amplitude impedance method” in the power industry standard are introduced and verified

the correct calculation formulas are derived. In addition

the shortcomings of low efficiency

insufficient security and accuracy in measuring capacitive current by injecting non-power frequency current from the potential transformer(PT)open delta side are studied. Then a new capacitive current measuring method of injecting non-power frequency current from the neutral point of a capacitor bank is proposed. With the help of mathematical theory-based derivation and experimental results and field tests

the accuracy of this method is verified while the influence of various factors on the test error with the new method is analyzed by the simulation test results.