Page 82 - E24 Electrical Notebook

78 - UPS Application Design Guidance

Introducing the Piller IP-System™ Coupled with energy storage and the ability to configure a massive UPS
system of up to 20 MW in low voltage, the IP-System is particularly suited
The Piller Isolated Parallel System (IP-System) reflects a new design to applications where minimising space and maximising return on
concept in the area of UPS topologies, which overcomes certain investment are high priorities. Reducing the number of redundant units
disadvantages of the conventional UPS configurations (i.e. N+x & N+N), to the minimum and avoiding units running in standby makes the
yet which merges their advantages into a highly reliable system topology. IP-System a green solution and a good choice, if an environmental
This topology is available at both LV and MV and allows repeated friendly and ecological power supply is desired.
paralleling of UPS modules with the benefit of automatic load sharing
and high operating efficiency, while ensuring sufficient fault isolation Mains
between the individual units.
UPS 1 UPS 2 UPS N
In such an IP-System, each UPS is connected to a common bus (IP-Bus)
by a 3-phase choke (IP-Choke), designed to limit fault currents to an IP- Bus
acceptable level but provide sufficient load sharing at the same time. IP- Choke
Each load is related to an individual UPS and is directly connected to the
UPS’s output. IP- Return Bus

Due to its load sharing capability, an IP-System is typically designed in Load 1 Load 2 Load N
an N+x redundant configuration, reducing the number of redundant units Piller IP-System Schematic
to a minimum while keeping the operating point of the UPS at a high level UPS Load
on the efficiency curve. The Isolated Parallel System provides an Mains Bypass (Critical)
exceptional method of combining the features found in Isolated- Typical S.B.
Redundant and Parallel-Redundant UPS configurations: shared MV / LV Connection
redundancy among UPS modules and output bus fault isolation in a large, Coupling Choke
multiple output, paralleled UPS System. What also distinguishes the
IP-System is the excellent maintainability and the outstanding fault MV Tx
tolerance, ensuring a highly reliable and robust power distribution for
various power critical applications. UNIBLOCK™
Machine
UNIBLOCK™ UBTD+ Diesel UPS – Operation
Isolated S.B.
In normal operation the load is fed via the coupling choke. The special Connection
design of the coupling choke allows a high level of decoupling between
the input and output and blocks all harmonics and transient events Mains Essential
between the input and output. Load

The coupling choke is tapped with the UNIBLOCK™ machine. The Alternative Connection
generator winding of this synchronous machine ensures the output Arrangements
voltage is kept constant irrespective of the mains voltage. The generator
winding feeds the loads with dynamic response similar to an ideal AC Piller UNIBLOCK™ DRUPS Configurations
supply. Peak currents and high short circuit current (up to 18 times
nominal current) can be supplied by the UNIBLOCK™ machine even in UNIBLOCK™ UBTD+ Module Ratings (Largest Available)
the event of a mains failure. In the event of a mains failure power flows
from the POWERBRIDGE™ (rotating kinetic energy store) or battery to Maximum Output Critical Bus Emergency Bus Combined Load
the load via the UNIBLOCK™ machine.
UNIBLOCK™ 50 Hz 60 Hz 50 Hz 60 Hz 50 Hz 60 Hz
If the mains does not return then the diesel starts and comes up to speed. UBTD+
The overrunning clutch then closes and the load is ramped on to the
diesel from the POWERBRIDGE™ / battery providing a soft load transfer. Single Output Diesel UPS (LV or MV) 2500 3000 N/A N/A N/A N/A
The POWERBRIDGE™ is then fully recharged and thus enables the full kVA kVA
stabilisation function (i.e. the POWERBRIDGE™ will stabilise the output
frequency during load steps on and off the diesel by providing power or Dual Output Diesel UPS (LV or MV) 2500 3000 2500 3000 2500 3000
absorbing power as required). On restoration of the mains, the output kVA kVA kVA kVA kVA kVA
voltage is synchronised to the mains and the input breaker closes and
the diesel is shut down. Dual Output Diesel UPS (LV or MV) 1670 2000 1100 1300 2770 3300
(Isolated Bus) kVA kVA kVA kVA kVA kVA
UNIBLOCK™ UBTD+ Diesel UPS - Dual Output Operation
Smaller ratings available.
In the basic form, the Piller UNIBLOCK UBTD+ provides 100% of its Combined power, lower UPS and higher Emergency possible.
available output as continuous Uninterruptible Power. However, it is All units available in low voltage to 600 Volts or for any medium voltage level.
available in alternative forms whereby the power can be split between
UPS (Critical Bus) power and Essential Bus like a standby generator –
this form is known as Dual Output Bus.

Depending upon the particular design requirements, it is sometimes
necessary or desirable to electrically isolate the short break loads from
the Critical Bus – this is known as Dual Output isolated bus. In this
configuration, the generator winding provides the Critical Bus source and
the motor winding of the UNIBLOCK™ machine becomes a generator
for the Essential Bus.

The two circuits are isolated by virtue of the transformer action between
the windings and so the two outputs are electrically isolated. In other
circumstances, it can be preferential to use the same alternator for both
supplies particularly in MV solutions. This flexibility is uniquely available
with the UNIBLOCK™ UBTD+ system.

Piller UK Ltd Tel : 01285 657721
Westgate Fax : 01285 654823
Phoenix Way
Cirencester Email : uk@piller.com
Glos GL7 1RY Website : www.piller.com