Operation Manual – AXA 2400 Compact Power– 30 - 90 kVA
General Description
Document no. 578.650BB
Page 9 of 91
Capacitor Board (A5):
This module includes the following functions:
•
Input and Output RFI filters to reduce the EMI/EMC emission into the mains and output
to such
a level that surrounding equipment is not disturbed. In addition, the two filters prevent voltage
transients from reaching vital parts in the ground power unit.
•
Resistors in combination with the soft start contactor (Q5).
•
Magnetic Wave shaping circuit.
•
Link from the main supply phases L1-L2-L3 to the Supply Module (G1) via the breaker (Q4).
•
Coil voltage for the output contactor(s), controlled via A2:Q1 on the Interface Board.
Input Choke & 12-pulse Transformer (L1 / T1):
The combination of the choke, the 12-pulse transformer, the magnetic wave shaping circuit and the
rectifier situated at the inverter module, ensures an almost sinusoidal line current with a Total Current
Harmonic Distortion of 5% (ITHD) at 90 kVA/kW and a unity power factor. This means less stress on
the main supply network and the distribution transformers.
Inverter Module:
Beside the rectifier (V1-V6), the DC-filtering capacitors (C1-C6) and the soft start circuit (Q5)
controlled via X12, the module consists of a 3-phase inverter which generates a 400 Hz voltage system
with a very low harmonic content and individual phase control. Two PCBs (gate drive top & gate drive
bottom) are used to interface between the control unit and the IGBTs. Voltage supervision of the DC-
filtering capacitors is likewise performed at the gate drives via X19.
