NI CompactRIO and PXI for Turbine Speed Controller Simulation and Testing in Power Plants

Author(s):
Wouter Termote - Laborelec

Industry:
Industrial Controls/ Devices/ Systems, Energy/Power

Products:
Compact FieldPoint, CompactRIO, PXI/CompactPCI, LabVIEW FPGA Module, LabVIEW

The Challenge:
Upgrading the existing turbine speed controller test equipment and software to a user-friendly, automated, and transportable test and simulation environment.

The Solution:
Improving the software by using the National Instruments LabVIEW graphical interface and upgrading the hardware to an easy-to-transport single device, which enabled instant visualization, greatly reduced development and installation time, and maintained full use of the existing system’s highly sophisticated features.

©At Laborelec, we conceived the first version of the Advanced Real-Time Interactive Simulation of Turbines (ARTIST) net simulator in 1985. Over the next 20 years, we added a considerable number of sophisticated features to the software.

With this system, we tested the steam turbine speed controllers in power plants. During planned maintenance, we connected the speed controllers to the ARTIST system, which simulated the external components, the state of the turbines, the state of the power grid, and the power demand. Depending on these states, the turbine speed controllers needed to properly synchronize the turbo-alternators, regulate the valves, and so on. It was very important to test these features as unplanned downtime because an error in the speed controller of a classical, gas, or nuclear power plant can result in high costs and even damage the turbines.

For instance, we used ARTIST to verify that controllers could immediately take control of the velocity of a steam turbine when we disconnected it from the power grid. We also used it to test turbine controller behavior during frequency fluctuations on the power grid. The limitation of the existing system was its portability. The system was housed in a large container with several strip chart recorders and analog stand-alone devices. We could not place the control cabin next to the turbine speed controllers. We integrated the system with an extensive program written in C++ – the listing of code was equal to five thick books. Combined together, this resulted in time-consuming maintenance as well as upgrade limitations.

Implementation of the New ARTIST System

We updated both the hardware and software in 2005. First, our experts upgraded the ARTIST software to a graphical environment. They replaced more than 50,000 lines of C++ programming code with NI LabVIEW code and reused hard-to-reprogram core C Code in LabVIEW. By doing this, our experts gave users a more realistic view of the industrial process. For instance, users could immediately monitor speed controller behavior under varying power grid conditions. Moreover, we replaced the former, somewhat unwieldy homemade ARTIST hardware with an easy-to-transport system consisting of National Instruments CompactRIO and PXI. This greatly increased mobility and reduced the installation time of the ARTIST simulator near the turbine speed controller.

Hardware Implementation

With this modular software approach, we could make quick hardware changes. We could tie each external signal to any input on the system. The ARTIST program has a configuration module that defines each input. We could tie the input to a real-world I/O signal or to an internal software simulation. In the latter case, we could use the system as a training simulator for operators and maintenance technicians, or we could use it to test new process control structures. OPC connectivity to other processes or to an external DCS was also possible. We could plug in models developed using the The MathWorks, Inc. MATLAB^® and Simulink^® software.

For real-world I/O, we could use this system to incorporate National Instruments Compact FieldPoint, with control-loop rates up to 100 Hz, and/or NI CompactRIO, to integrate the simulation of a high-speed turbine tachometer signal and its degrading signal quality over time.

The entire system consists of a PXI chassis and PXI controller with the Microsoft Windows XP operating system. The PXI chassis also contains an NI PXI-5404 frequency generator to generate a 50 Hz net signal.

Valuable Tool for Different Users

ARTIST is not just a validation tool for plant operators. Maintenance personnel, for instance, use ARTIST to test speed controllers after repairs or replacements, or to examine new process control structures and their parameters. Also, Electrabel, a leading European energy company and No. 1 on the Benelux market, uses ARTIST in its training center to instruct new employees.

With the ARTIST program, engineers can conduct the on-site testing of most of the governors for the thermal power generation units in Belgiumas well as the commissioning after modifications. The new ARTIST will be used for the first time during the revision of the turbines at the nuclear power plant in Doel No. 4 in 2006. Based on user feedback, Laborelec will continue upgrading the net simulator for maximum performance.

MATLAB^® and Simulink^® are registered trademarks of The MathWorks, Inc.

For more information, contact:
Wouter Termote
Laborelec SV
Dept. AISY
Rodestraat 125
B-1630 Linkebeek
Belgium
Tel: +32 (0)2 382 03 22
Fax: +32 (0)2 382 02 41
E-mail: wouter.termote@laborelec.com
Web: www.laborelec.com

 

 

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