LVTrans
LVTrans
Open source
transient simulations software
for hydraulic piping systems
Made in LabVIEW
Svingen Tech
Svingen Tech is the name of the company housing LVTrans (this web site essentially). dr.ing Bjørnar Svingen made the first version of LVTrans in LabVIEW in 2001 within a couple of hours as a "quick and dirty" MOC solver for one single pipe (MOC = the Method of Characteristics). It was used for acoustic calculations of gas risers in the North Sea*. From there it was used in several projects in the oil business for a few years, and was developed and extended all along.
In 2003 Statkraft and Sira-Kvina, both hydro power utility companies, got involved with several projects, and LVTrans gradually became tuned towards transient simulations of hydro power plants, incorperating all the necessary elements (turbines, tunnels, surge shafts, PIDs etc). The turbine element is rather special. It uses the physical model by Professor Nielsen, and does not need any tables that are impossible to get hold of in any case.
From 2005/2006 and after, LVTrans have been used almost exclusively on hydro power plants. It is the main simulation program used by Statkraft, and is the core of a predictive governor use to control Tonstad power plant (4x160 MW + 1x320 MW). The predictive governor has been in operation continuously since 2014, and is a key component for fast and accurate balancing power between hydropower in Norway and wind power in Denmark and Germany. LVTRans is also the main simulation software for Hymatek Controls, and has been used for several years by Rainpower. It is used by students at NTNU, and in lectures about transients in hydro power.
A key element of LVTrans is LabVIEW by National Instruments. LabVIEW enables an engineer or scientist to focus on the engineering problem - the science and equations, while all the graphical user interface quirks, as well as low level hardware IO, are already taken care of by LabVIEW. This is true for pure software development as well as complex predictive real-time systems controlling entire power plants.
A blog about hydraulic transients can be found here.
One can say that the "wire programming" of LabVIEW is not the most intuitive way of doing core numerical computations, and few will disagree. One can also say that a proprietary programming language with binary source files, as is the case for LabVIEW, is not the most practical solution for open source software. From the beginning of LVTrans, and for several years after, ANSI C was used for the core waterhammer solution. Later C++ was used. C++ offered a substantially improved overall solution compared with ANSI C due to object oriented approach. A core numerical C++ library has long been considered the optimal solution. This C++ library is "plugged" straight into existing LVTrans source files, enabled by the special object oriented MOC (Method Of Characteristic) procedure used in LVTrans. This opens up a range of other possibilities, with and without LabVIEW as HMI or IO for embedded systems. Time and other practicalities (compiler, IDE**) has never allowed this to fully happen. It is however, difficult to see very far into the future without a transition to C++. This "project" already has a name; CMOCE, C++ Method of Characteristics Engine.
Another possibility is Python. Python has in many ways become de facto standard as a light-weight programming language in many sciences and engineering fields. Limited support for Python has been natively included in LabVIEW for several years already. Both LabVIEW and C/C++ are compiled languages, Python is not. For pure numerical calculations, LabVIEW executes about 1.5-3 times slower than C++, while Python executes 10-1000 times slower than C/C++. Such a low executing speed is problematic for larger and complicated calculations that have to be done continuously. As a future HMI and other things not dependent on raw numerical computational speed, Python could certainly be a good solution.
The license of LVTrans is owned by dr.ing Bjørnar Svingen and by SINTEF Energy. The license is a BSD license.
* Acoustics in gas pipelines is mathematically equivalent to general transients in liquid-filled pipelines.
** As of October 2023, the light-weight and open source IDE previously used for the C++ code is no longer maintained.
dr.ing Bjørnar Lona Svingen
also works at Aker Solutions, after the Aker take over of Rainpower in 2022.
Svingen got his PhD at the Water Power Laboratory at NTNU in 1996. Since then he has been working both in the industry and in research and academia. In the industry he has been working at Kværner, and later under several company names resulting from different merges and take overs when the Kværner industry giant stumbled and fell in the late 1990s. He is a co founder of FDB, which is where LVTrans first started. He has worked at SINTEF Energy for several years, and has been assiciated with NTNU since the student days. He held an Associate Professor II appoitnment there (20%) from 2015 to 2022.
Svingen has been working with transient simuations all this time, as well as field and laboratory work, both in hydropower and in the oil and gas sector.
Svingen is a member of:
The international scientific commitee at Pressure Surges Conference by bHr Group in the UK
IEC TC-4 WG36. Standardization of transient calculations of hydro power plants.
When he is not fiddling with LVTrans, some transient simulation or a predictive controller, he can be found building and/or flying airplanes. Svingen has both a PPL and a microlight license. He flyes at Værnes Flyklubb where he also is a microlight instructor, and at NTNU Flyklubb where he tows gliders. He is a long time member of the EAA (Experimental Aircraft Association), and is currently building two airplanes.
