Method for determining compensation (Power Factor correction Guidelines)

The location of L.V capacitors banks in an installation constitutes the mode of reactive power compensation, which may be central (one location for the entire installation), by sector or group (section-by-section), at load level, or some combination of the latter two.

In principle, the ideal reactive power compensation is applied at a point of consumption and at the level required at any moment in time.

In practice, technical and economic factors govern the choice.

The location for connection of capacitor banks in the electrical network is determined by:

1. the overall objective (avoid penalties on reactive energy relieve transformer or cables, avoid voltage drops and sags)
2. the operating mode (stable or fluctuating loads)
3. the foreseeable influence of capacitors on the network characteristics
4. the installation cost.

Central compensation

The capacitor banks are connected at the head of the installation to be compensated in order to provide reactive energy for the whole installation.

This configuration is convenient for a stable and continuous load factor.

Group compensation (by sector)

The capacitor banks are connected at the head of the feeders supplying one particular sector to be compensated. This configuration is convenient for a large installation,with workshops having different load factors.

Compensation of individual loads

The capacitor banks are connected right at the inductive load terminals (especially large motors). This configuration is very appropriate when the load power is significant compared to the subscribed power.

This is the ideal technical configuration, as the reactive energy is produced exactly where it is needed, and adjusted to the demand.