Configuring the power supply
To determine the maximum possible cable length, the total maximum permissible resistance of the transformer and supply lines up to the input terminals of the line choke must be taken into account.
The resistance values of transformers with an apparent power of > 630 kVA can be disregarded for the calculation of the total resistance value.
For transformers ≤ 630 kVA, the following resistance values can be used across the board:
- 250 kVA: 8 mΩ
- 400 kVA: 5 mΩ
- 630 kVA: 3 mΩ
The maximum permissible total resistance values depend on the line voltage of the supply system and the maximum necessary overload in motoring operation.
By taking the maximum permissible total resistance and the associated voltage drop (± 10%) into account, a reliable operation of the regenerative power supplies and other electronic components in the control cabinet is guaranteed.
The maximum permissible total resistance values that are specified relate to a single regenerative power supply. If several regenerative power supplies are operated on one transformer, only the permissible total resistance value of a regenerative power supply needs to be considered.
The permissible total resistance values are listed in the following tables.
