SOLAR - More than a Scale
29 August 2003 12:06
Future-oriented technology for today’s energy generation. Vattenfall Europe Generation AG & Co. KG as a leading European energy company banks on high tech and automation for their operational facilities. In the Jänschwalde brown coal power station over one hundred trains and thousands of metres of piping systems as well as conveyors assure the raw material transport for production whereby every day up to 82000 tons of brown coal are mined in the nearby Jänschwalde and Cottbus North open cast pits and transported to the power station where it is converted into electricity or used for the generation of long-distance heating. The incoming volumes of brown coal and additionally delivered limestone for the desulphurisation of waste gas as well as outgoing volumes of filter ash / dust and plaster (totalling approx. 14200 tons per day) for the construction material industry must be recorded and incorporated – fully automatically – in the logistic sequence.
The solution for fully automated weighing is supplied by the weighing specialist from Augsburg, Pfister Waagen Bilanciai GmbH: SOLAR – the dynamic in-motion scale. Prerequisite to the selection of the right railway scale system is of course the technical expertise and know how of the manufacturer. According to Hans-Ulrich Hauk, the technician responsible for superstructure and track construction at the Jänschwalde power station and head of the railway scale project, price was also in the end a prime factor in decision-making.
Pfister Waagen Bilanciai GmbH also managed to keep within the tight deadlines set for the completion of the complex task: following the order award in July 2002 installation work and the extensive software link-up began in October. In the space of only one month the entire system, adjusted and calibrated, could be commissioned. The brief mounting time of just one week for the SOLAR weighing system is largely due to the foundation-free embedding of the measuring sleepers (sheet steel structure with the dimensions of a conventional concrete sleeper) in the existing ballast. Repacking of the ballast following installation by a tamping machine is all that is required. Neither ballast bonding nor complex foundation work is required for the perfect function of the system, which is also an advantage should the measuring sleeper be moved or repacking be performed at a later date. Shear sensors record and analyse any settling of the measuring sleepers in order to eliminate the influence of ballast movements on the measuring operation.
The SOLAR measuring principle: the measuring sleepers are linked to high-precision measuring amplifiers in the track close to the weighing section. From there, data is transferred via an interference-proof optical fibre cable to a weighing PC containing the measuring processing software, MVO Plus. The verifiable part of MVO Plus is SSWSOFT which performs verifiable recording and storage of weighing data such as wheel, axle and wagon weights as well as calculating axle geometries. A further highly demanding task is the software linkage to the higher-level system used by the VEAG. As the VEAG handles supplying, disposal and service on the track systems via the operations control system of the LAUBAG (formerly Lausitzer Braunkohle AG) central railway operation (BLS-ZEB) a fully automated data exchange must take place between the two companies. All data is gathered at the BLS-ZEB database server (Oracle database) and is stored and saved there centrally. Due to this sophisticated software linkage and database communication the following test operation period from January 2003 onwards was specified in the contract and represented the most difficult part of the project. However, even this hurdle was overcome as early as February 2003 and the entire system was handed over.
Two basic types of material flow on rails takes place at the Jänschwalde power station:
1) Delivery of brown coal and limestone, i.e. weight recording of the train with filled wagons as first-time weighing and the train with empty wagons as second weighing on leaving the factory premises. After eliminating the engine weight and taking into account the tare weight of the wagons the delivered net material weight is established.
2) Supplying of filter ash, dust and plaster to external companies, i.e. first-time weighing of the empty train and wagons and second weighing of the loaded train with filled wagons. On eliminating the engine weight and taking into account the tare weight of the wagons the net weight of the departing material is, in turn, established.
In both cases the goods must be recorded and incorporated – fully automatically – in the logistic sequence. The data is stored, administered and used for further processing centrally on the external BLS-ZEB database server. Approx. 25 incoming and outgoing weighing jobs are performed daily, i.e. 50 verifiable in-motion weighing operations per day at precision class 0.5 (to OIML R 106) as prescribed for goods under public law. 2 and 4-axle wagons with public transport goods are weighed with no restriction on wagon type.
In the meantime two in-motion weighing systems (both from Pfister Waagen Bilanciai GmbH) are in operation at the Jänschwalde power station:
- the previously installed SIRIUS weigh rail (track 69) with weighing electronics and software for partially automatic weighing operation and
- the new SOLAR in-motion weighing system with measuring sleepers (track 68) and fully automated weighing operation.
The SIRIUS weigh rail is linked via the SOLAR railway scale computer to the BLS-ZEB system Oracle database. All data are transferred to the central database for automatic processing. The selection or combination of weighing systems is operations-dependent.
Summarised version of the SOLAR fully automated weighing sequence:
- arrival of the loaded train at the factory premises
- the signal box assigns the appropriate free track for train entry
- the track is “enabled” via the train notification system and thus the weighing job for SOLAR is issued. A data record is supplied by the BLS-ZEB database server to the MVO weighing software and the scale is activated
- in-motion weighing with SOLAR (optimum traversing speed for weighing 5-15 km/h)
- whereby the following functions are performed automatically via the MVO weighing software:
wagon type detection and verifiable weighing recording
subtraction of the traction vehicle weights within the wagon group, regardless of their position
assignment of the wagon weights to the weighed wagons independently of the direction of travel as the wagon groups may be pushed or pulled across the railway scale
- the data record with all first-time weighing information (train number, arrangement, weights etc.) is transferred to the BLS-ZEB database server, saved and stored there intermediately
- the train enters the power station, is unloaded and proceeds to the exit track
- the signal box assigns the appropriate free track for departure
- the track is „enabled“ via the train notification system and thus the weighing job issued to SOLAR. The first-time weighing data record is supplied in the MVO Plus weighing software and the scale is activated
- second in-motion weighing with Solar with the same automatic functions. The train compositions are not changed between the first and second weighings but they may be „turned around“ (pulled or pushed). Should however the number of wagons change this will be signalled as an error to the BLS-ZEB.
- the data record is transferred with all information on the first and second weighing (train number, train type, arrangement, weights etc.) to the BLS-ZEB database server and stored there. It is here that the accounting files are prepared following the second weighings.
The weighing sequence for the SIRIUS weigh rail differs in only one aspect: weighing is triggered manually.
- the train is assigned. The number and arrangement of the wagons, loaded material and direction of travel (pulled or pushed) are entered on the PC.
- the weighing job is issued either by the signal box operator or allocating clerk. A second workplace is therefore featured for the allocating clerk.
- the data flow between SIRIUS and the database server takes place automatically via the SOLAR railway scale computer in the usual manner.
A bi-directional data exchange therefore takes place for both weighing systems between the MVO Plus Solar software and BLS-ZEB system: the receiving and acknowledging of weighing jobs.
Further special features - weighing data management upgrades with the MVO Plus Solar software package:
- recording of error messages as well as „manual / automatic“ mode change
- optional manual or automatic mode
- setting the standard „Automatic“ operating mode at the program start
- MVO automatic interface (controlling the MVO software via UDP interface)
Remote maintenance of the weighing PCs is performed via pcAnywhere. This software is operated in host mode and is incorporated in the operating system auto start. As such, swifter support is achieved and it is assured that during operation the program is not terminated by an operator.
The bottom line: Solar unites the benefits of maintenance-free proven long-term operation and high verifiable precision.
For more information on this company:
Pfister Waagen Bilanciai - Static and Dynamic Railway Scales and Test Systems
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