PF3000 Power Filter Characteristic Tester User Manual
Figure A-2 typical wiring connections about "H" bridge capacitor group
In Figure A-2, "H" bridge consists of four bridge arms and the neutral lines connecting with four
arms which there are 144 capacitors in series or parallel to form "H" bridge. The total current
vector which flows through the capacitor denoted Ic. The current flowing through the neutral line of
"H" bridge is called the "imbalance current vector," recorded as Ibph, and the positive direction of
the two current vectors is shown in the figure A-2.
By the capacitor manufacturing process and assembly technology constraints, the capacitor
groups installed in the 500kV converter station will be a situation that the capacitor inherent
imbalance current exceeds the permissible range. To prevent the partial capacitor in the capacitor
group failure resulting the other capacitors’ damage, it needs to set the value of imbalance current
alarm Ibj according to the capacitor internal components’ over-voltage permissible value. For
imbalance current exceeds the standards capacitor group, need to adjust the location of electrical
connections of the part of the capacitor unit, so that the imbalance current Ibph of capacitor is less
than half of the imbalance current alarm value Ibj.
Showing in figure A-2 "H" bridge connection capacitor groups, set C1, C2, C3, C4, respectively,
"H" bridge four arm capacitance. Have the following relationship:
C1 is equal to C1_1, C1_2, ..., C1_35, C1_36 series capacitance
C2 is equal to C2_1, C2_2, ..., C2_35, C2_36 series capacitance
25
