Voith (Germany)

Manufacturing companies are increasingly challenged by the frequency and diversity of required changes to their production systems. To address this, a change-specific and company-individual methodology for Manufacturing Change Management (MCM) was developed. This paper presents a multi-perspective evaluation of the methodology through an industrial case study, a simulation game, and expert interviews. The results indicate that the methodology enhances process efficiency, streamlines documentation and method selection, and improves transparency in change handling. The cost-benefit analysis demonstrates a rapid amortization. The broad fulfilment of key requirements confirms the practical value of the approach, while also revealing opportunities for further improvement.

Abstract Hydraulic systems can be subjected to excitations induced by complex flow structure developed in any system’s component. The interaction between the hydraulic system and the excitation source can be predicted by performing a co-simulation between two independent simulation codes. One is resolving the fluid pipe system with a one-dimensional compressible code whereas the other one computes the three-dimensional flow in a given hydraulic system’s component which is the source of excitation. In the field of hydroelectric power plants, the one-dimensional SIMSEN software is widely used to compute transient dynamic response of the hydraulic system. The need to couple this tool with a 3D finite volume method of computational fluid dynamics is growing. The aim is to predict resonance or instability phenomena between hydraulic machines and piping systems. To reach this purpose, the FMI co-simulation feature has been implemented in SIMSEN as a part of the FMI library which is considered as a standard communication protocol between two simulation codes solving a set of ordinary differential equations. This protocol has been used to couple SIMSEN software with the Ansys CFX solution. The implementation has been validated with simulations of two test cases involving different physics of interest occurring in hydroelectric power plants: the pressure wave propagation in the piping system and the mass oscillation phenomenon in a surge tank.

The indirect pole-to-pole connection is a common damper winding design in salient pole synchronous hydro generators. The inter-pole damper current passes radially through the pole end and tangentially through the rotor rim to reach the neighbouring pole. There are two types of indirect pole-to-pole connections investigated in this paper where the damper bars are connected to A) the steel pole end plate or B) an extra copper plate between the pole end plate and the pole lamination. The aim of this paper is to provide an analytical prediction method of the indirect pole-to-pole impedance. Therefore, the methodological assumptions are compared with 3D FE simulations and the analytical calculation results are compared with measurements. The findings of this investigation are important parameters required for analytical and 2D FE calculations to predict the currents in the damper winding, which compensate unbalanced loads, torque oscillations and unbalanced magnetic pull.

Structural vibrations caused by magnetic forces in synchronous machines constitute a multi-domain problem involving both electromagnetic and mechanical phenomena. Recent years have seen an increasing effort in the scientific community to improve the capabilities of the calculation models used to assess this problem. On the one hand, this trend contributes to increasing the accuracy of the calculated results obtained. But on the other hand, the increased complexity of the models tends to make the identification of cause-effect relationships more difficult. In this context, this work proposes a new graphical tool for the comprehensive analysis of stator core vibrations in synchronous machines. The development of a holistic diagram for the root cause analysis of the electromagnetic and mechanical phenomena, called the vibration cause diagram (VCD), is presented and applied to two example machines of different sizes. The analysis method obtained is particularly useful during the design phase of a new machine or for the troubleshooting evaluation of existing machines.

The presence of mineral sediments in water led to significant erosion damage to a power plant in the Chilean Andes. The plant is operated by Enel and is equipped with three vertical Francis power units, with approximately 25 MW each operating under a net head of around 120 m. The overall machine condition with reported significant damage on the turbine caused by erosion led to a modernization project with runner replacement and output and efficiency increase. In order to ensure a proper sediment measurement and quantification during the turbine operation, Voith developed, supplied and installed a sediment monitoring system in power unit #01. The monitoring system, developed using the OnCare.Health Hydro platform, applies optical sensors installed directly in the spiral case inlet section to measure the water turbidity. Other operational parameters are recorded, processed and stored together in the same database. Two optical sensors were installed in the spiral case inlet section and provide turbidity readings. The first one is positioned directly flush to the flow. The second one is located in a sampling pipe that collects water from four different points of the same cross section. An automatic water sampler installed in the sampling pipe collects water periodically, which is sent to a laboratory for particle analysis. The laboratory results allow an identification of important parameters such as sediments concentration, particle sizes and materials that are used for correlation with the indicated turbidities. The main data analysis shows that the power unit operated most of the time close to the rated condition. A comparison between turbidities indicated by both sensors shows an offset, probably associated to the particles distribution along the cross section. A system calibration process successfully correlated suspended sediment concentration and turbidity values to allow online indications of the sediment concentration. The system has been operating for almost two years in a close cooperation with the engineering teams of the plant owner and system provider. Main results and system findings for this application will be presented and discussed in this paper.

A new calculation approach for the contribution of the stator end winding field to the clamping plate field in large synchronous machines based on Biot–Savart (BS) law and Schwarz–Christoffel (SC) mappings is proposed in this article. The new field calculation appeals due to its low computational cost in the range of hundreds of milliseconds. The field normal to the clamping plate as well as the tangential clamping plate flux is compared to magnetostatic 3-D finite element analysis (FEA) simulations for multiple operating points of a test generator geometry, with both calculation approaches being in good agreement.

Safe Dynamic Positioning (DP) is crucial for the mission success of an offshore ship. The Voith Schneider Propeller (VSP) has proven itself as a reliable propulsion system for DP ships because it generates thrust forces in longitudinal and transverse direction very quickly and accurately. The fast thrust generation of the VSP makes it possible, in addition to the DP task, to significantly reduce the roll motion of the ship. Due to the high DP accuracy and the reduced roll motion, the VSP allows the vessel to increase significantly its working range with respect to the weather window.

The assessment of fish passage through turbines is important to develop cost-efficient environmental solutions and strategies that avoid individual fish injuries and, therefore, enhance the fish population development in a catchment. As part of the FIThydro project, fish passage analysis were performed for the bulb turbine in Bannwil, the S-turbine in Guma and the bulb unit at the test facility in Obernach.Numerical modelling in principle provides the most comprehensive information on hydrodynamic conditions in the turbine passage. Many details of the main relevant stressors on fishes can be derived. The information of different stressors like pressure, strike, shear and turbulence can be extracted with high accuracy assuming that a fish pathway follows a streamline through the turbine. The accurate prediction of the stressors and the validation with measurements enables the designer to develop a turbine that reduces the stress on the fish and, hence, increase the fish survival rate.The survival rate also strongly depends on biological aspects of a fish species. Besides the reaction of the fish on the different stressors, complex parameters like swim behavior or preferred swim elevations are of high importance on the survival rate. However, these parameters vary among different fish species.CFD simulations of different turbines are performed and simulation results were compared to measurements with the Barotrauma Detection System (BDS) sensors at the test cases in Guma and Bannwil, as well as live fish tests at the test facility in Obernach. The fish behavior was modeled in the CFD based evaluation method. Studies related to swimming speed, fish orientation and especially the actual passage location demonstrate the sensitivity of these parameters on the fish survival rate. Another aspect was the influence of operating conditions on fish passage. A wide spectrum of operating conditions was analyzed and fish passage hill-charts for different stressors were generated. This knowledge enables an adapted power plant operation related to migration movements of certain fish species. The CFD based analysis method shows to be a powerful tool to improve fish passage through a turbine by changing hydraulic design and by adapting operational modes. Relative improvements to conventional designs and operation can be quantified.