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Supplying water to Jakarta –
using the latest inverter technology
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SUPPLY
Greater efficiency and lower costs
in supplying water to Indonesian metropolis
The Indonesian city of Jakarta is experiencing rapid and continuous growth – an enormous
challenge for PT Thames PAM Jaya (TPJ): This joint venture between Thames Water Utilities
Ltd., U.K., and the Indonesian state water utility PAM Jaya has supplied the daily water needs
of millions of people throughout the eastern half of Jakarta for 25 years. In order to be able
to control the pumping processes with greater precision, to reduce the load on the mechanical
systems and at the same time harness considerable potential for energy savings, several
pump systems have been operating since last September, using variable speeds for the first
time. These are controlled by the SIMOVERT MV drive converter which is particularly reliable
and easy to service, thereby ensuring high availability of the overall system.
The latest HV-IGBT technology with a host of benefits
SIMOVERT MV is the first drive converter of its performance
class with HV-IGBT (High-Voltage Insulated Gate Bipolar
Transistor) power semiconductors. These simplify the
construction of the medium-voltage drive converter to a
dramatic extent. The result: SIMOVERT MV is particularly
reliable, compact and easy to service.
Compact and flexible
As in many retrofit projects, the compact design of
SIMOVERT MV was a crucial factor. Thanks to the compact
design and the small footprint, the converter could be
installed in the existing control room without any difficulty.
The space situation was made even easier by the flexible
construction of drive systems using SIMOVERT MV. For
example, the input transformer could be positioned outside
the control room.
High availability and easy to service
The reliability of the IGBT technology guarantees a high
availability of the entire pumping system. The servicefriendly design, together with preventive monitoring
functions, ensure minimum downtimes: for example, the
HV-IGBT Powercards can be replaced within a matter of
minutes without any special tools, while other components
such as the control modules or starting unit are easy to
handle and simply need to be plugged in.
Low-wear and reliable operation for pumps and
motors
Soft-start and stop functions with programmable acceleration and deceleration time reduce the mechanical loads
and the pressure waves in the pipes when starting up and
shutting down. The cost of wear and tear and maintenance
is reduced to the absolute minimum. Extensive protection
functions integrated into the converters prevent overloading
and increase the reliability of the drive system. Any blocking
of the motor, for example, is detected and results in a safe
shutdown instead of overheating. Critical speeds, which
could excite resonances in mechanical systems, can be
avoided by the programming of skip frequencies.
Compatibility
As the withstand voltage of the insulation on the existing
motors was not known, SIMOVERT MV was equipped with
an output filter. This guarantees a sinusoidal output voltage
and thus permits the operation of motors at the rated
output, no matter which manufacturer they originate from.
Motors that run with square-law torque characteristics do
not overheat even at low speeds.
High performance without harmonics
The constantly high output factor – regardless of the motor
load and speed – limits the reactive power to a minimum,
and meets the output factor cos γ of 0.96 required by the
operators as well as the harmonics requirement. In order
to limit these, SIMOVERT MV is equipped as standard with
a 12-pulse input rectifier. The measurement of the harmonics before and after integration of the SIMOVERT MV drive
converter was part of the turnkey solution.
In addition to the supply and delivery of the converter
system, this also includes the appropriate transformers, the
installation, integration, cabling and integration of the drive
systems, training of the future operating personnel and a
maintenance contract for the drive system.
SIMOVERT MV is the first medium-voltage drive converter to operate with HV-IGBT power semiconductors.
This ensures simple construction and reliable
operation.
Retrofitting at pumping stations
TPJ has built up a water supply concept based on three separate
locations: A total of 25 pumps, driven by medium-voltage motors
(3300 V/3000 V), operate in the water treatment plants at Buaran
and Pulo Gadung, as well as the water distribution center in the
Clinincing suburb. Previously, all 25 pumps operated at a constant
speed. In order to gain greater control over the flow rate and
pressure in the distribution system, TPJ decided to upgrade four
of the 25 constant-speed motors to variable-speed drive systems.
To do this, the company opted for a drive converter. This now
enables the drive systems to react swiftly to changing operating
conditions, which is necessary for optimum process control.
Greater precision and economy
More precise process control is not the only advantage of automatic
speed control. It also harnesses considerable potential for energy
saving, especially where pumps are concerned. In comparison with
the previous mechanical volumetric flow control with throttle
valves, in which the constant-speed motors are always on full
power, the converted variable-speed systems now adapt themselves
precisely to the operating requirement at all times. This means
that the motor only consumes as much power as is actually necessary. The result: energy requirements are significantly lower than
for constant-speed motors of similar output in throttled operation.
The upgraded TPJ pump systems require at least 20 to 25 percent
less energy.
Perfectly integrated
The four motors that TPJ had converted were about 20 years old
and were not designed for variable-speed operation with regard
to their winding insulation. In addition, it was necessary to ensure
that the existing cooling was also sufficient at lower operating
speeds. A reduced shaft output after the upgrade was likewise
unacceptable, as the pumps had to supply the full rated output
when needed. The inverters were to be integrated into the existing
control, instrumentation and power cabling and accommodated
with minimum space requirements up to 200 m away from the
motors.
During the planning and consultation phase of the project, Siemens
undertook a very close investigation of the existing controlgear,
instrumentation and motors. The result of the analysis: Under the
given conditions, the SIMOVERT MV drive converter was the
optimum solution.
© Siemens AG 2003
PUBLICIS
The information provided in this brochure contains
merely general descriptions or characteristics of performance which in case of actual use do not always
apply as described or which may change as a result
of further development of the products. An obligation
to provide the respective characteristics shall only exist if expressly agreed in the terms of contract.
Siemens AG
Automation and Drives
Large Drives
Vogelweiherstrasse 1–15
D-90441 Nuremberg, Germany
www.siemens.com/simovert-mv
Subject to change without prior notice 07/03
|
Order No. E20001-A100-P500-X-7600
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DISPO 21503
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21D6577 MK.LD.XX.LDAL.52.3.03 WS 09032.
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Printed in Germany
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Further information can be found at
www.siemens.com/simovert-mv