Supplying water to Jakarta – using the latest inverter technology wat ater er 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 | DISPO 21503 | 21D6577 MK.LD.XX.LDAL.52.3.03 WS 09032. | Printed in Germany | Further information can be found at www.siemens.com/simovert-mv