Distribution feeders
Fault
Distribution
substation
Line voltage with sag Compensating voltage Restored voltage
+
Transformer
Dynamic voltage
Sensitive load
restorer (DVR)
Converter
DC storage
supercapacitor
325
Applications of Electrochemical Supercapacitors
FIGURE 8.5
Sketch of improved power quality on distribution side by DVR.
other electrical devices. Power fluctuation is a serious matter that can severely
affect sensitive devices. ESs can be used as energy storage devices for systems designed to improve the reliability and quality of power distribution.
For example, static condensers (statcons) and dynamic voltage restorers
(DVRs) are systems intended to inject or absorb power from a distribution
line to compensate for voltage fluctuations. They require DC energy storage devices that can store energy and allow it to be drawn. The length of
voltage perturbation that can be effectively compensated for depends on the
energy density of the DC storage device. Most voltage perturbations on a
distribution bus are short-lived, most not lasting more than ten cycles [10].
For this application, the limited storage capability of an ES is not a problem.
Furthermore, because an ES has the advantage of fast discharge time, it can
respond quickly to voltage disturbances.
In general, batteries are not generally suitable for short duration and fast
response applications such as statcons and DVRs because their lifetimes
are shortened considerably when their charge is drained. Figure 8.5 shows
improved power quality on the distribution side of a DVR.
It is worth noting that power quality applications require instantaneous
reliable ride-through power. Using traditional lead–acid batteries for such
rapid, deep-cycle electric power demands is harmful to batteries. Also due to
the higher ESRs of traditional batteries, their use in this kind of application
produces higher voltage drops on their terminal voltages and extra losses
due to the pulsating characteristic of the load current. To ensure constant
readiness when batteries are used, an application will require significant
Fault
Distribution
substation
Line voltage with sag Compensating voltage Restored voltage
+
Transformer
Dynamic voltage
Sensitive load
restorer (DVR)
Converter
DC storage
supercapacitor
325
Applications of Electrochemical Supercapacitors
FIGURE 8.5
Sketch of improved power quality on distribution side by DVR.
other electrical devices. Power fluctuation is a serious matter that can severely
affect sensitive devices. ESs can be used as energy storage devices for systems designed to improve the reliability and quality of power distribution.
For example, static condensers (statcons) and dynamic voltage restorers
(DVRs) are systems intended to inject or absorb power from a distribution
line to compensate for voltage fluctuations. They require DC energy storage devices that can store energy and allow it to be drawn. The length of
voltage perturbation that can be effectively compensated for depends on the
energy density of the DC storage device. Most voltage perturbations on a
distribution bus are short-lived, most not lasting more than ten cycles [10].
For this application, the limited storage capability of an ES is not a problem.
Furthermore, because an ES has the advantage of fast discharge time, it can
respond quickly to voltage disturbances.
In general, batteries are not generally suitable for short duration and fast
response applications such as statcons and DVRs because their lifetimes
are shortened considerably when their charge is drained. Figure 8.5 shows
improved power quality on the distribution side of a DVR.
It is worth noting that power quality applications require instantaneous
reliable ride-through power. Using traditional lead–acid batteries for such
rapid, deep-cycle electric power demands is harmful to batteries. Also due to
the higher ESRs of traditional batteries, their use in this kind of application
produces higher voltage drops on their terminal voltages and extra losses
due to the pulsating characteristic of the load current. To ensure constant
readiness when batteries are used, an application will require significant