In this paper

the reactive power compensation capacitor bank

which is commonly used and has different primary connection

is described

the applicability of capacitance measurement of two kinds of primary connection without disconnection is discussed.It is shown through theoretical analysis and simulation discussion on the working principle of the testing device of capacitance without disconnection that correct test data can be obtained by the use of capacitance testing device without disconnection in accordance with different wiring connection and corresponding measures.Finally

it is proved by the actual test that for the wiring connection where series capacitor is connected to the side of neutral point

if primary connection mode remains unchanged

correct capacitance measurement of each phase cannot be made until the earthing switch opens.