Technology
The two main UPS technologies available on the market are:
• transformer-based, useful when primary and secondary sources come from different mains with different neutral systems,
• transformerless, which offers the advantages of high efficiencies combined with a low footprint.
Both of these technologies have their advantages and drawbacks. The challenge is to make the right compromise, taking into account
site conditions with design constraints such as the footprint, neutral system, efficiency, short-circuit currents and so on. SOCOMEC can
provide customers with either technology, depending on the requirement.
Transformer-based and transformerless technologies
H5 H7 H11 H13 H17 H19
Traditional three-phase rectifier with thyristor
12-pulse rectifier
Low distortion rectifier DELPHYS MX
HARMONICS
THDI %
28
%
1
%
8
%
7
%
9
%
5
%
6
%
3,2
%
2,5
%
4,7
%
2
%
ASI 008 A GB
A "clean" IGBT rectifier
This eliminates any disturbance on the
upstream network (power source and
distribution).
• This rectifier technology guarantees the
supply of current with an exceptionally low
rate of harmonic distortion: THDI < 2.5 %.
A consistent rectifier
• The performance of the IGBT rectifier is
independent of frequency variations that
could be produced by the generator set.
• The power factor and THDI at the rectifier
input are constant whatever the battery
charge status (continuous voltage level) and
the load rate of the UPS.
An economical IGBT rectifier
• The power factor upstream of the rectifier
is 0.99, reducing by 30% the used kVA
compared with conventional technology.
The reduction in input current results in
a saving in terms of the size of sources,
cables and protective devices.
• Rectifier capabilities:
- low upstream THDI,
- gradual, timed restarting,
- possibility of suspending battery recharge
when operating with a generator set.
• This allows the impact caused when the
generator set is engaged to be reduced, as
well as the energy used and the footprint.
DELPHYS MX guarantees optimal
compatibility with your low voltage electrical
power supply system and, in particular, with
your generator sets:
• sinusoidal current at rectifier THDI input:
<4.5 % without filter,
• increased power factor upstream of the
rectifier: 0.93 without filter, reducing the
current consumed, and therefore the size of
cables and protective devices,
• gradual, sequential start-up of the rectifiers
in parallel, facilitating take up by the
generating set,
• delayed battery recharge when running
on generating set to reduce power
consumption.
The SVM (digital Space Vector Modulation),
along with the isolation transformer installed
on the inverter output, provide:
• perfectly sinusoidal output voltage THDV
<2 % with linear loads and < 3 % with
non-linear loads,
• output voltage precision even when the load
is completely unbalanced between phases,
• an immediate response to major variations
in the load, without deviating the output
voltage (± 2% in less than 5 ms),
• a very high short-circuit capacity up to 4 In
(Ph / N) allows selectivity,
• a complete galvanic isolation between DC
circuit and load output.
SVM, the latest high performance
components and IGBT power bridges enable
the supply of:
• non-linear loads with high crest factor up
to 3,
• active power without derating, for loads
with a lagging power factor and up to 0.9
leading.
SVM, digital Space Vector Modulation
UPS technologies
Technology
Static Transfer Systems (STS)
Static Transfer Systems (STS) are intelligent
units that transfer the load to an alternative
source when the primary source is out of
tolerance. This ensures "high availability"
of the power supply for sensitive or critical
installations.
The purpose of STS devices is to:
• ensure the redundancy of the power
supply to critical installations by means of
two independent power sources,
• increase power supply reliability for
sensitive installations,
• facilitate the design and expansion
of installations that guarantee a high-
availability power supply,
• increase the overall site flexibility, allowing
easy and safe maintenance or source
replacement.
STS systems incorporate reliable and
proven solid-state switching technologies
(SCR), enabling them to perform fast, totally
safe automatic or manual switching without
interrupting power to the supplied systems.
The use of high-quality components,
fault-tolerant architecture, the ability
to determine the location of the fault,
management of faults and loads with high
inrush currents: these are just some of the
characteristics that make STS systems
the ideal solution for achieving maximum
power availability.
STS can also protect against:
• main power source failure,
• spurious tripping of upstream
protective devices,
• mutual disturbances caused by faulty
equipment (short-circuit) supplied by the
same power source,
• operating errors (circuit opening)
occurring in the supply chain.
Static Transfer Systems: some examples of usage
Normally, STS provide redundancy between
2independent UPS systems.
Each STS is sized according to the load
(or set of loads) it protects.
It is advisable to install the STS device as
close as possible to the load, so as to ensure
redundancy of the upstream distribution and
to keep the single fault point (the conductor
between STS and load) as short as possible.
The use of several STS also provide electrical
load segregation.
STS
S
TA
T
YS
STATYS
Power distribution A
Load 1
UPS A
STS
UPS B
DELPHYS
DELPHYS
DELPHYS
DELPHYS
S
TS
S
T
A
TYS
STATYS
Load 2
STS
S
TS
S
T
A
T
YS
STATYS
Load 3
STS
Power distribution B
ASI 049 A GB
Static Transfer Systems (STS) for
high availability architecture
125Catalogue 2015
Static Transfer Systems (STS)
Static Transfer Systems ensure high business
availability and provides site maintenance
agility.
The ‘2N + STS’ architecture ensures the load
is always supplied by high power quality on
each input, even if one power distribution
is down due to critical fault or for long term
maintenance (e.g. source replacement or
failure of the electrical infrastructure).
The combination of a multi-source
architecture and STS connecting the load to
two independent sources ensures they are
always supplied even if one of them is down.
The critical facility therefore benefits from very
high fault tolerance.
In both example, the STS can be centralised
(one high STS rating for each power
distribution switchboard) or distributed
(close to each server room, row, rack, etc.).
The choice of either solution depends on
the installation to be protected and on the
expected availability or the requested level of
maintainability.
B
B
DELPHYS
DELPHYS
UPS A
DELPHYS
DELPHYS
UPS B
SERVERS
STS
STATYS
STATYS
STS
STATYS
STATYS
SERVERS
STS
STAT
YS
STATYS
STS
STAT
YS
STATYS
A
A
STS
STS
PDU
PDU
STS STS
PDUPDU
STS
STS
PDU
PDU
Power distribution A
Power distribution B
SERVERS
STS
STATY
S
STATY
S
STATY
STATYS
STS
STAT
YS
STATYS
BA BACA CACB CB
DELPHYS
DELPHYS
UPS A
DELPHYS
DELPHYS
UPS B
SERVERS
STS
STATYS
STATYS
STS
STATYS
STATYS
SERVERS
STS
STATYS
STATYS
STS
STATYS
STATYS
SERVERS
STS
STATYS
STATYS
STS
STATYS
STATYS
DELPHYS
DELPHYS
UPS C
Power distribution A Power distribution B Power distribution C
STS STS
PDUPDU
STS STS
PDUPDU
STS STS
PDUPDU
Static Transfer Systems: some examples of usage
STS in a 2N architecture
STS in a multi-source architecture
Technology
Expert Battery System (EBS) technology
is a system which manages the battery
charger.
It responds to the working temperature to
preserve battery life and reduce operating
costs by:
• charging according to an algorithm
which adapts to the environment and the
condition of the battery,
• eliminating overloading effects due
to permanent floating voltage, which
accelerates the corrosion of the positive
plates and causes the separators to dry
out,
• isolating the DC battery bus,
(independent charger function).
Premature ageing, caused by residual
ripple from the inverter bridge is
eliminated.
Tests carried out by SOCOMEC on several
brands of batteries, together with years
of experience, show that battery life can
be enhanced by up to 30% with the use
of EBS compared to a traditional battery
management system.
Expert Battery System: protecting your battery investment
Available with distributed batteries,
DELPHYSGP allows you to optimise battery
size thanks to shared battery operation. This
reduces the overall system footprint, the
weight of the required batteries, the battery
monitoring system, the amount of wiring
needed and amount of lead.
Associated with an appropriate connection
design (fuses and coupling switches), this
solution also allows you to increase the
availability of the battery set and UPS units in
case of internal fault.
Shared battery: optimisation of battery size for parallel systems
Back-up storage
Distributed battery Shared battery
126 Catalogue 2015