Solutions & expertise in hydropower transients and operation through softwares and engineering services since 2007.

Hydropower Dynamics Engineering SA (HDE) is a company based in Switzerland, focusing on modelling, simulation and analysis of hydroelectric power plants dynamic behavior. Our company has expertise in the fields of Hydraulic, Mechanical and Electrical engineering and promotes multiphysics approaches which includes the dynamics of each part of the installation with rational methodology.

• Hydroelectric Transient Analysis
• Water Hammer Calculation
• System Stability Analysis
• Control System Optimisation
• Ancillary Services and Grid Code Compliance
• CFD and Complex Flow Simulations

Simulation Software for Hydraulic & Electric Systems. Adjustable Speed Drives

Physically based Digital Twin for Hydro Power Plant Transient Monitoring

Simulator for Hydro Power Plant Operator Training

Dr Sébastien ALLIGNÉ
Project engineer Hydro Mechanical Expert
Mechanical Eng. Dipl. ENSHMG-INPG
sebastien.alligne@hdynamics.ch
Phone : +41 21 691 01 22

Competences

• Hydroacoustic modelling
• Transient phenomena in hydroelectric power plants
• 3D unsteady CFD simulation
• Hydraulic machines
• Mechanical and hydraulic engineering
• System stability analysis

Dr Christian LANDRY
Project engineer Hydro Mechanical Expert
Mechanical Eng. Dipl. EPFL
christian.landry@hdynamics.ch
Phone : +41 21 691 01 22

Competences

• Hydroacoustic modelling
• Transient phenomena in hydroelectric power plants
• Power plant energetic optimisation
• Hydraulic machines
• Mechanical and hydraulic engineering
• System stability analysis

Jérémy SCHMID
Project engineer
Master of Science in Energy and Environment Eng. (MSE), HES-SO
jeremy.schmid@hdynamics.ch
Phone : +41 21 691 01 23

Competences

• Numerical optimization methods and regression models
• Hydroacoustic modelling
• Transient phenomena in hydroelectric power plants
• Hydraulic machines
• Mechanical and hydraulic engineering

Dr Daniel BINER
Project engineer Hydro Mechanical Expert
Master of Science in Engineering (MSE),
Industrial Technologies, HES-SO
daniel.biner@hdynamics.ch
Phone : +41 21 691 01 23

Competences

• Mechanical design
• Hydroacoustic modelling
• Computational Fluid Dynamics
• Structural Finite Element Analyses
• Prototype field tests
• Strain measurements
• Fatigue calculations

Laetitia KURSNER
Administrative Manager
laetitia.kursner@hdynamics.ch
Phone : +41 21 691 01 21

Competences

• Administrative management and commercial strategy implementation
• Software contract and billing management
• Coordination with external partners
• Bookkeeping with month-end reconciliation and financial statements
• Website, Social media and content management

Hydropower Dynamics Engineering SA (HDE) is founded in 2007, in Ecublens (VD), Switzerland, by Dr. Christophe Nicolet after completion of his doctoral thesis at the École Polytechnique Fédérale de Lausanne (EPFL). His research develops the hydraulic components of the SIMSEN software. This doctoral work is supervised by Prof. François Avellan and Prof. Jean-Jacques Simond, directors of the EPFL Laboratory for Hydraulic Machines (LMH) and Laboratory for Electrical Machines (LME), respectively.

SIMSEN development starts in 1992 at EPFL under the initiative of Prof. Jean-Jacques Simond. It begins with the EPFL master’s thesis in electrical engineering of Dr. Alain Sapin, who completes the first version of SIMSEN in 1996 as part of his doctoral work on electrical power system applications. With the software support of Mr. Philippe Allenbach, the first commercial version is released in 1998.

After this initial electrical engineering foundation, the extension of SIMSEN to hydraulic applications starts in 2001 with the master’s thesis in mechanical engineering of Dr. Christophe Nicolet, carried out at the EPFL Laboratory for Hydraulic Machines (LMH) under the supervision of Prof. François Avellan. This work initiates the hydraulic modeling developments that subsequently lead to major expansions of SIMSEN in hydraulic, electrical, and control-system applications. Further developments benefit from substantial financial support from Innosuisse, the Swiss Innovation Agency, formerly CTI.

The strong collaboration among these contributors makes the creation of Power Vision Engineering Sàrl, the company’s original name, a natural next step in 2007. That same year, the company establishes an agreement with EPFL, the owner of SIMSEN, for software distribution, support services and training seminars. Since its inception, HDE delivers high-quality engineering services and innovative software solutions for the dynamic behavior of hydropower systems.

Shortly after its founding, Dr. Nicolet contributes to major hydraulic transient studies for key Swiss hydropower projects, including:

• The Hongrin-Léman pumped storage plant (FMHL) expansion from 240 MW to 420 MW (2007–2016),
• The recommissioning of the 1,200 MW Cleuson-Dixence power plant, completed in 2010, and
• The development of the 900 MW Nant de Drance pumped storage plant, equipped with variable-speed motor-generators (2012–2022).

In 2011, after Prof. Simond’s retirement, the EPFL agreement extends to software support and maintenance. The same year, HDE starts a six-year collaboration with EPFL, ALSTOM, ANDRITZ, and VOITH. The program enhances SIMSEN capabilities and develops a new graphical user interface.
In 2013, the company patents the Hydro-Clone® Digital Twin (EP 2 801 879 B1, EP 3 285 128 B1). The solution monitors hydraulic transient phenomena in hydropower plants through a real-time, physics-based approach built on the SIMSEN platform.
From 2013 to 2017, HDE participates in the HYPERBOLE European Project (No. 608532, FP7 ENERGY 2013), contributing to advanced hydraulic modeling and turbine innovation.
From 2019 to 2024, HDE is a member of the research consortium in the XFLEX HYDRO Project (No. 857832), under the Horizon 2020 Framework Programme, focusing on flexible hydropower technologies and enhanced operational strategies.
In 2020, the company moves to new offices in St-Sulpice (VD), Switzerland, to support its growth. In 2025, Power Vision Engineering Sàrl becomes a public limited company under the new name Hydropower Dynamics Engineering SA (HDE). This change marks a new phase of expansion in Switzerland and internationally and strengthens HDE’s position as a leading hydropower engineering firm.

Today, HDE employs ten professionals, seven of whom hold doctoral degrees. The company provides advanced R&D and engineering services to power utilities, electromechanical equipment manufacturers, and engineering firms worldwide. HDE brings more than 19 years of experience and has contributed to more than 30 pumped-storage projects, from feasibility studies and detailed design to commissioning and troubleshooting.

HDE’s expertise covers modeling, simulation, analysis, and optimization of hydropower plant operation and related electromechanical equipment. The company specializes in:

• Hydraulic and electrical transient analysis, including water hammer, mass oscillation, and machine transients in variable-speed systems;
• Power plant system stability;
• Variable speed pump-turbine unit simulation;
• CFD and FEM computation;
• Control system optimization;
• Safety and emergency sequence evaluation;
• Ancillary services capability assessment;
• Grid code compliance;
• Energy production optimization.

Today, HDE continues to develop, distribute, and maintain SIMSEN. It remains the exclusive provider of related support and training services.

1992: SIMSEN development starts at EPFL under the initiative of Prof. Jean-Jacques Simond.

1996: Dr. Alain Sapin completes the first version of SIMSEN as part of his doctoral work on electrical power system applications, following his EPFL master’s thesis in electrical engineering.

1998: The first commercial version of SIMSEN is released with the software support of Mr. Philippe Allenbach.

2001: The extension to hydraulic applications starts with the EPFL master’s thesis in mechanical engineering of Dr. Christophe Nicolet at LMH under the supervision of Prof. François Avellan.

2007: Dr. Christophe Nicolet completes his doctoral thesis at EPFL, further developing the hydraulic components of SIMSEN.

2007: Power Vision Engineering Sàrl is founded, and an agreement with EPFL establishes the framework for SIMSEN distribution, support services, and training seminars.

2011: The EPFL agreement extends to software support and maintenance, and a collaboration with EPFL, ALSTOM, ANDRITZ, and VOITH enhances SIMSEN capabilities and develops a new graphical user interface.

2013: The Hydro-Clone® Digital Twin is patented as a real-time, physics-based monitoring solution built on the SIMSEN platform.

2013–2017: HDE contributes to the HYPERBOLE European Project, supporting advanced hydraulic modeling and turbine innovation.

2019–2024: HDE contributes to the XFLEX HYDRO Project, focusing on flexible hydropower technologies and enhanced operational strategies.

2025: Power Vision Engineering Sàrl becomes Hydropower Dynamics Engineering SA (HDE), marking a new phase of development in Switzerland and internationally.