Test Management without a Database: Voith Hydro Tests Turbines with Technical Data Management, DIAdem, and NI DataFinder

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"By using powerful default components, TDM, NI DataFinder, and DIAdem, and without using a database, we considerably reduced our creation and maintenance costs."

- Dipl.-Inf. Karl Finkl, a-solution GmbH

The Challenge:
Meeting future renewable energy generation challenges and further expanding the leading position of Voith Hydro as a supplier of hydroelectric power plant turbines.

The Solution:
Developing software for all aspects of testing, from test commission to test management, using NI DIAdem software, NI DataFinder, and the NI Technical Data Management (TDM) solution instead of expensive, complicated database software.

Author(s):
Dipl.-Inf. Karl Finkl - a-solution GmbH

Data Organization – The Key to a Consistent Test Realization

When we develop turbines, we must execute many tests of varying complexity. Construction engineers define and commission these tests. A test commission contains information about the actual test, the unit under test, the test rig configuration, and the testing conditions. The software on the test rig uses the commissioned data to execute the test according to the specifications, and saves the measurement data and results. Construction engineers use the data generated on the test rig for evaluations and reports. Calculation results from the analyses complete the test file.

It is important to save the descriptive test information and the measurement and evaluation data in the same file. This ensures clear test documentation when reports are created and clear identification of test data, even after several years. A-solution GmbH  tailored the application software for the customer by customizing DIAdem, the software for technical data processing.

Initially, the TDM format only defines a hierarchical data structure and functions for accessing its elements. We created a TDM-based, application-oriented data model for Voith Hydro by specifying channels and channel groups and by defining metadata. In DIAdem, the user can use a simple browser to view, read, and write this information and the data structures.

The DIAdem default functionality in NI DataFinder constantly searches all test files for meta information and creates an index file from this data. The user can execute a query with this index to quickly and systematically find files. The query can be a full-text search or can be executed with logical operators. DIAdem offers easy-to-handle user functions for both query modes.

The Measurement File Is Created When the Test Is Commissioned

Voith Hydro carries out different tests on models of the power plant turbines, such as engine characteristic values tests, oscillation tests, or cavitation tests, where the calculation models are projected onto the real turbine and plant during the measurement.

The four main program parts are the test commission, the test sequence control, the measurement data acquisition, and the analysis and report generation. The information is transferred from one program to the next by the TDM test file. The respective program uses the information from the previous programs and adds its own data. Only one file per test is required. The file saves all relevant data in each test phase. Figure 1 shows the programs and the data streams in the turbine test.

Construction engineers develop tests with the help of a test commission. In this case, previous tests can function as templates either to add more measurement points to an existing test, or to change the specifications of a similar test and save it as a new test commission. NI DataFinder can search for appropriate templates.

The following information must be included in the test commission:

  • General information (test number, test type, test date, customer)
  • Model and prototype information (geometry, coefficients for calculations)
  • Test rig specifications (stationary test parameters)
  • Status information (target test rig, test status = “commissioned”)

The above information is saved as metadata (properties) in the test file. Variable test rig specifications such as set values (RPM, torque, and drop height) are used for measuring and determining the characteristic values. This information is saved as a table in the channel group set points. The table columns are the actuating variables of the test rig control and the table rows are the different states (measurement points) at which characteristic values are determined.

On the test rig, the user can use NI DataFinder to execute a query for test commission of a test rig and select a commission from the list received. The test sequence control reads the relevant test commission data from the TDM file and transfers the data to the test rig control. The test rig control adjusts the set point specification and reports the adjusted state to the measurement data acquisition.

The Test Management Is Free

The measurement data acquisition software measures and visualizes sensor data. The values of the prototype can be calculated and visualized during the measurement with the coefficients from the commission file and the calculation models. If the test rig control reports an adjusted state, the data is buffered. Characteristic values are calculated from the data in the buffer and saved in rows in the result table as the results channel group. The set point table records that the measurement point was measured. The measurement is complete when every measurement point from the set point table is measured. Because tests can contain several hundred measurement points and are time consuming, the test can be interrupted at any time and continued later.

The construction engineer can start initial evaluations with the evaluation and report function while the test is running because the test file is refreshed after every acquired measurement point. This can initiate a premature change to the test commission or terminate the test. If a test runs for several days, this saves a lot of time and money.

The results are evaluated and displayed in DIAdem where the measurement and metadata of the TDM test file is used to calculate and document the results in reports. The calculation results are also saved in the test file. NI DataFinder helps find relevant tests in the archive for comparative evaluations.

Summary

We used the TDM format to store descriptive test information and measurement and evaluation data consistently in one single file. All the processes involved in the test refer to this file. NI DataFinder is free of charge with DIAdem, eliminating the need for a database system. The NI DataFinder search function is used in all program sections for various tasks, which simplifies our job. The program sections created by customizing DIAdem automate sequences as much as possible and minimize entries. By using powerful default components; TDM, NI DataFinder, and DIAdem and no database, we considerably reduced creation and maintenance costs.

Author Information:
Dipl.-Inf. Karl Finkl
a-solution GmbH
Industriestrasse 39
Gröbenzell at Munich D-82194
Germany

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