Circutor SVGm-3WF-100C-480, Инструкция по эксплуатации

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38
SVGm
Instruction Manual
4.- OPERATION
4�1�- OPERATING PRINCIPLE
The currents consumed by the loads present in any installation have two components: an
active
com-
ponent, which generates an effort, and a
reactive
component, generated by the inductive or capacitive
nature of the load.
Φ
Active
Reactive
Curr
ent
Figure 32: Current Components�
Both components are added when current flows through electrical conductors, which must be sized ac-
cordingly to transmit the resulting current. However, only part of these conductors are used to transmit
current, so the capacity of the power distribution lines is underused.
Therefore, distribution companies usually impose penalties on consumers with a low
active
to
reactive
current ratio. This current ratio is known as the power factor , or cos
Φ
, according to whether it takes
into account the content of harmonics or only the fundamental frequency component.
The effects of
reactive
currents in the conductors of distribution lines can be minimised with two
methods:

Passively
, by adding reactive loads with the opposite sign to that of the loads of the instal-
lation. For example, adding capacitors to handle inductive loads.

Actively
, by generating a current with the same magnitude as the active current to compen-
sate, in the opposite phase.
The SVGm is a device included in the second group. It uses the current measured with external current
transformers to generate a counter-phase current, with the magnitude required to obtain the
cos Φ
programmed for the installation.
SVG
Resulting
Installa
tion
Figure 33: Operation of the SVGm�
The
SVGm
operates as a current generation source, so it can compensate capacitive and inductive cur-
rents. In addition, its operation does not depend on the content of harmonics in the network, so it can