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John Salmon - One of the best experts on this subject based on the ideXlab platform.

  • Guidelines for Selecting Minimum Capacitance for a Floating Bridge Dual Inverter Drive
    2019 IEEE Energy Conversion Congress and Exposition (ECCE), 2019
    Co-Authors: Chatumal Perera, Gregory J. Kish, John Salmon
    Abstract:

    A method for selecting the Floating Bridge capacitance of a dual inverter drive with an open ended winding induction machine is presented. It is shown that the Floating Bridge capacitor voltage can be kept constant even during large step transients in motor speed reference and load torque. Hence, the capacitor can be made very small and can be chosen based on the steady state voltage ripple, which is a result of the inverter switching action. The ripple voltage is a function of the motor speed, torque and inverter switching frequency. Equations are provided that can predict the ripple voltage over the whole operating range of the motor. A guideline equation for selecting the capacitor based on the predicted worst case ripple and drive parameters is also presented.

  • wide speed range operation of pmsm using an open winding and a dual inverter drive with a Floating Bridge
    Energy Conversion Congress and Exposition, 2013
    Co-Authors: Reaz Ul Haque, A. M. Knight, Mohammad Sedigh Toulabi, John Salmon
    Abstract:

    A controller is described for a 3-phase PMSM that uses an open winding and a dual inverter drive with a Floating Bridge. The drive has a voltage boosting function that: extends the high-speed range of the PMSM; operates the main inverter Bridge at unity power factor above the base speed; compensates for battery voltage fluctuations. The main features of the controller presented are: (a) coordinated control of the two inverters to supply the motor with the demand voltage and frequency; (b) the Floating Bridge dc capacitor voltage can be regulated and its output voltage used to boost the machine terminal voltage when required; (c) the motor speed is controlled via torque control is independent of the Floating Bridge dc voltage control. Simulation results are used to clarify the motor-drive characteristics in the speed range extension region. Experimental results show that a significant speed range extension is achievable even when using a PMSM with a very low inductance.

  • a method for supply voltage boosting in an open ended induction machine using a dual inverter system with a Floating capacitor Bridge
    IEEE Transactions on Power Electronics, 2013
    Co-Authors: Jeffrey Ewanchuk, John Salmon, C Chapelsky
    Abstract:

    An operational approach to an induction machine is presented that uses an open winding connected to a dual inverter system. A Floating capacitor inverter Bridge boosts the fundamental voltage available to the machine and arbitrarily sets the operating power factor of the main inverter Bridge connected to the dc battery power source. During operation, the motor current charges the Floating Bridge dc capacitor voltage to a naturally stable dc voltage level and the ac voltage delivered to the machine is the resultant sum of the two inverter Bridge voltages. Machine voltage boosting is then achieved by adjusting the fundamental phase angle difference between the two inverters to control the charge stored in the Floating Bridge capacitors. With the Floating Bridge providing reactive voltage support and therefore boosting the available supply voltage to the induction machine, there are two main outcomes: minimization of the supply current required for operation beyond the base speed of the electric machine, and supply voltage regulation of the drive system. Experimental results are used to verify the operation of the Floating Bridge arrangement by examining the load power factor angle and the phase difference between the two Bridges. Results are presented for a passive RL load to illustrate the supply current reduction at high fundamental frequency operation, and a modified 2-hp, 1800-r/min induction to illustrate the dc voltage supply droop compensation.

  • a square wave controller for a high speed induction motor drive using a three phase Floating Bridge inverter
    Energy Conversion Congress and Exposition, 2010
    Co-Authors: Jeffrey Ewanchuk, John Salmon
    Abstract:

    A square-wave voltage control scheme is presented for a high speed induction motor drive that uses a dual 3 phase inverter system and open ended motor windings. The drive main inverter Bridge is connected to the dc battery source and a second inverter Bridge is Floating with no dc power source. The Floating Bridge dc voltage is allowed to naturally fluctuate and used to provide voltage boosting at high speeds, well above the maximum possible when using just the main Bridge. This voltage boosting can also be used to compensate for fluctuations in the dc battery voltage. A second controller feature forces the main Bridge to operate at a unity displacement power factor, lowering the main inverter losses and the rms current drawn from the battery - while maximizing the reactive support available to the machine. Significantly, these features are obtained inherently without having to switch between different inverter switching patterns or monitor the load current magnitude or phase. Experimental results are used to illustrate the principal of the natural reactive compensation of the Floating Bridge and to verify drive operation on a 2HP, 1800 rpm induction machine.

Torgeir Moan - One of the best experts on this subject based on the ideXlab platform.

  • Effect of wave inhomogeneity on fatigue damage of mooring lines of a side-anchored Floating Bridge
    Ocean Engineering, 2021
    Co-Authors: Jian Dai, Torgeir Moan, Bernt J. Leira, Hagbart Skage Alsos
    Abstract:

    Abstract Mooring systems are important structural components of very long Floating Bridges. They effectively limit the transverse motions of the Bridge under environmental loads. They also add viscous hydrodynamic damping to the entire system. The safe and economical design of mooring systems is thus important but also challenging especially when the wave conditions are inhomogeneous. In this paper, a computational study is carried out to investigate the responses of the mooring lines for a 4.6 km long fjord crossing Floating Bridge accounting for inhomogeneous wave conditions. Based on the structural responses, this study also attempts to evaluate the fatigue damage in the mooring lines by using different fatigue analysis methods. The accuracy of the spectral methods is examined by comparison with the conventional rainflow cycle counting algorithm. Numerical studies are conducted to obtain an indication of the effect of various wave inhomogeneities on the fatigue damage in the mooring lines.

  • inhomogeneous wave load effects on a long straight and side anchored Floating pontoon Bridge
    Marine Structures, 2020
    Co-Authors: Jian Dai, Torgeir Moan, Bernt J. Leira, Marit Irene Kvittem
    Abstract:

    Abstract In this paper, we present a numerical study on the hydroelastic response of a 4.6 km long fjord crossing Floating Bridge subjected to wave loads. The Bridge is straight in design and supported by 35 pontoons along its full length. To limit the response to horizontal loads, four clusters of deep water mooring lines are engaged to increase the transverse stiffness of the Bridge. Owing to the very large span across the fjord, inhomogeneity in the wave field exists. This study examines the various effects of inhomogeneous wave loads on the dynamic responses of the Floating Bridge. These include the spatial variations of the wave direction, significant wave height and peak period as well as the coherence and correlation of waves along the entire length of the Floating Bridge. For the purpose of comparison, the dynamic Bridge responses under homogeneous wave load cases are also studied. In addition, the effects of wave load components and short-crestedness are presented and discussed.

  • Extreme responses and associated uncertainties for a long end-anchored Floating Bridge
    Engineering Structures, 2020
    Co-Authors: Zhengshun Cheng, Zhen Gao, Torgeir Moan
    Abstract:

    Abstract Very-long Floating Bridges represent an innovative marine structure for crossing wide and deep fjords. During the design of a Floating Bridge, extreme structural responses at a specified probability of exceedance are required to be properly evaluated for ultimate limit state (ULS) design check. This study addresses the estimation of extreme structural responses due to wind and wave loads and associated uncertainties. An end-anchored Floating Bridge, about 4600 m, is considered in a case study. The long-term extreme responses are estimated by using a simplified engineering approach, in which the long-term extreme response is approximated by the one-hour short-term extreme responses at a high fractile (90% in this study) for selected short-term sea states. The extreme responses are expressed as μ + κ · σ , where μ and σ are the ensemble mean and standard deviation, and κ is a multiplying factor. Statistical analyses indicate that the structural responses, including axial force, strong and weak axis bending moments of the Bridge girder, are close to follow a Gaussian distribution. A simplified analytical method, the Gumbel method and the mean upcrossing rate (MUR) method are employed to estimate the multiplying factor κ and extremes. The κ estimated by these three methods are generally close, varying in the vicinity of 4. The κ and extremes estimated by the simplified method have a much smaller variation than the Gumbel and MUR methods. Statistical uncertainties and model uncertainties in the extreme value prediction are also addressed. Based on the results of 10 sets of 10 1-h ensembles, the mean and coefficient of variation (CoV) of μ , κ , σ and extremes of structural responses of 10 1-h simulations under two selected sea states are evaluated. The CoV of σ is less than 0.045, but the CoV of κ is relatively large, mainly between 3.5 × 10 - 2 and 6.5 × 10 - 2 . The CoV of extremes estimated by the simplified analytical method is fairly small, less than 0.035. While the CoV of extremes estimated by the Gumbel and MUR methods are much larger and can reach 0.137 and 0.158, respectively. In practical design of Floating Bridge, only a limited number of simulations (e.g. 10 1-h) are conducted to predict the extreme structural responses. This will introduce statistical uncertainties and should be corrected by a factor for a conservative estimate. A simplified procedure to derive the correction factor is presented in this study. For the Floating Bridge considered with 10 1-h simulations, the correction factor is recommended to be 1.1 when the absolute value of mean μ is smaller than σ , and be 1.2 when the absolute value of mean μ is larger than σ , in order to achieve a 90% conservative estimation of extreme.

  • Floating Bridges and Submerged Tunnels in Norway—The History and Future Outlook
    WCFS2019, 2020
    Co-Authors: Torgeir Moan, Mathias Egeland Eidem
    Abstract:

    To improve the efficiency of land transport, Bridges, submerged tunnels and subsea tunnels are introduced to replace ferries to cross straits. For wide and especially straits with a large depth or very soft bottom, Floating Bridges or submerged tunnels are attractive. Modern Floating Bridges can be traced back to the pontoon Bridge design implemented in the 1940s, and the notable Hood Canal Bridge in 1961. More recent Floating Bridges include the two Norwegian Floating Bridges: the 845-m long Bergsøysund and the 1246-m long Nordhordland Floating Bridges built in 1992 and 1994, respectively. Submerged Floating tunnels have been considered as an option for strait crossings, especially wide crossing such as the Gibraltar and Messina straits and the Høgsfjord in Norway. So far submerged Floating tunnels have not been built, while immersed tunnels have been used in many places, essentially in relatively shallow water. Currently, the Norwegian Public Road Administration (NPRA) is assessing replacing ferries across 8 fjords by providing Bridges or submerged tunnels on the Coastal Highway Route E39 Project. The width of the strait crossings is up to 5 km and the water depth is up to 1300 m. The NPRA is currently considering three alternative Floating Bridge concepts: curved, end anchored Floating Bridge or straight, side anchored Floating Bridge with mooring system and Floating suspension Bridge with pylons supported by TLP or spar Floating bodies; as well as submerged tunnel type concepts. This paper presents an overview of relevant concepts, their characteristic behaviour and design criteria for serviceability and safety, especially dynamic response due to environmental and accidental loads, with a highlight on development trends.

  • Extreme Response Analysis of an End-Anchored Floating Bridge
    Volume 7A: Ocean Engineering, 2019
    Co-Authors: Zhengshun Cheng, Zhen Gao, Torgeir Moan
    Abstract:

    Abstract During the design of a Floating Bridge, extreme structural responses are required to be properly evaluated for ultimate limit state (ULS) design check. This study addresses the estimation of extreme structural responses for an end-anchored curved Floating Bridge. The Floating Bridge, about 4600 m, consists of a cable-stayed high Bridge part and a pontoon-supported low Bridge part. The long-term extreme responses are approximated by using a engineering approach, i.e., the environmental contour method. The sea state with 100-year environmental conditions is considered, and a 90% fractile is used to calculate the short-term extreme responses by using the Gumbel method and the mean up-crossing rate (MUR) method based on 100 1-hour simulations with different seeds. The extreme responses are expressed as μ + κσ, where μ and σ are the ensemble mean and standard deviation, and κ is a multiplying factor. Numerical results show that structural responses are close to Gaussian distributed. κ of axial force and strong axis bending moment along the Bridge girder estimated by both the Gumbel and MUR methods vary in the vicinity of 4. κ estimated by the two method deviates, especially for axial force. Moreover, for both methods the estimated κ deviates more significantly if fewer ensembles are used.

Michele Mengoni - One of the best experts on this subject based on the ideXlab platform.

  • electric drive based on an open end winding surface pm synchronous machine with a Floating capacitor Bridge
    IEEE Transactions on Industry Applications, 2020
    Co-Authors: Albino Amerise, Michele Mengoni, Luca Zarri, Luca Rovere, Andrea Formentini, Pericle Zanchetta
    Abstract:

    A speed control scheme is presented for a three-phase surface permanent magnet synchronous machine with an open-end stator winding fed by a three-phase inverter and a Floating Bridge inverter. The latter is used to compensate for the reactive power of the main inverter and to maximize the active power received by the motor, without exceeding the available stator current and dc-link voltage. To reduce the switching losses, the dc-link voltage of the Floating inverter Bridge varies depending on the operating condition of the motor and the controllability requirements of the system. The experimental results show that a significant improvement in the speed range at constant power is achievable, proportionally to the dc-link voltage of the Floating Bridge inverter.

  • control system for open end winding surface pm synchronous machines with a Floating capacitor Bridge
    European Conference on Cognitive Ergonomics, 2018
    Co-Authors: Albino Amerise, Michele Mengoni, Luca Zarri, Luca Rovere, Andrea Formentini, Pericle Zanchetta
    Abstract:

    A speed control scheme is presented for a 3-phase permanent magnet synchronous machine with an open-end stator winding fed by a dual inverter system with a Floating Bridge. The Floating Bridge inverter is used to compensate the reactive power of the main inverter and, hence, to maximize the active power delivered to the motor in compliance with the constraints of a limited current and voltage. The DC-link voltage of the Floating Bridge varies depending on the operating condition of the motor in order to reduce the switching losses and ensure the controllability of the system. The experimental results show that a significant improvement in the width of the speed range at constant power is achievable in the flux weakening region.

  • control scheme for open ended induction motor drives with a Floating capacitor Bridge over a wide speed range
    IEEE Transactions on Industry Applications, 2017
    Co-Authors: Michele Mengoni, Angelo Tani, Giovanni Serra, Luca Zarri, Albino Amerise, Domenico Casadei
    Abstract:

    An electric drive for high-speed applications is analyzed in this paper. The drive consists of a dual two-level inverter with a Floating Bridge, fed by a single voltage source, and a three-phase induction motor with open-ended stator windings. The Floating Bridge compensates the reactive power of the motor, so that the main inverter operates at unity power factor and fully exploits its current capability. The constant power speed range of the motor can be significantly extended depending on the dc-link voltage of the Floating inverter. The details of the control system are examined and the feasibility of an electric drive is experimentally assessed.

  • robust control of an open ended induction motor drive with a Floating capacitor Bridge over a wide speed range
    European Conference on Cognitive Ergonomics, 2016
    Co-Authors: Michele Mengoni, Angelo Tani, Giovanni Serra, Luca Zarri, Albino Amerise, Domenico Casadei
    Abstract:

    An electric drive for high-speed applications is analyzed in this paper. The drive consists of a dual two-level inverter with a Floating Bridge, fed by a single voltage source, and a 3-phase induction motor with open-ended stator windings. The Floating Bridge compensates the reactive power of the motor, so that the main inverter operates at unity power factor and fully exploits its current capability. The constant power speed range of the motor can be significantly extended depending on the DC-link voltage of the Floating inverter. The details of the control system are examined and the feasibility of an electric drive is experimentally assessed.

  • Control of an open-ended induction machine using a dual inverter system with a Floating capacitor Bridge
    2015 IEEE Energy Conversion Congress and Exposition (ECCE), 2015
    Co-Authors: Michele Mengoni, Angelo Tani, Gabriele Rizzoli, Giovanni Serra, Luca Zarri, Domenico Casadei
    Abstract:

    A speed control scheme is proposed for a 3-phase induction motor that uses an open-ended stator winding fed by a dual inverter system with a Floating Bridge. The Floating Bridge has a voltage boosting function that extends the constant power high-speed range of the induction machine and operates the main inverter Bridge at unity power factor. The proposed control scheme coordinates the two inverters that supply the motor, regulates the dc-link voltage of the Floating Bridge and boosts the machine terminal voltage at high speed. Simulation results are used to clarify the motor-drive torque capability in the high speed region. Experimental results show that a significant power improvement is achievable in the field weakening region.

Luca Zarri - One of the best experts on this subject based on the ideXlab platform.

  • electric drive based on an open end winding surface pm synchronous machine with a Floating capacitor Bridge
    IEEE Transactions on Industry Applications, 2020
    Co-Authors: Albino Amerise, Michele Mengoni, Luca Zarri, Luca Rovere, Andrea Formentini, Pericle Zanchetta
    Abstract:

    A speed control scheme is presented for a three-phase surface permanent magnet synchronous machine with an open-end stator winding fed by a three-phase inverter and a Floating Bridge inverter. The latter is used to compensate for the reactive power of the main inverter and to maximize the active power received by the motor, without exceeding the available stator current and dc-link voltage. To reduce the switching losses, the dc-link voltage of the Floating inverter Bridge varies depending on the operating condition of the motor and the controllability requirements of the system. The experimental results show that a significant improvement in the speed range at constant power is achievable, proportionally to the dc-link voltage of the Floating Bridge inverter.

  • control system for open end winding surface pm synchronous machines with a Floating capacitor Bridge
    European Conference on Cognitive Ergonomics, 2018
    Co-Authors: Albino Amerise, Michele Mengoni, Luca Zarri, Luca Rovere, Andrea Formentini, Pericle Zanchetta
    Abstract:

    A speed control scheme is presented for a 3-phase permanent magnet synchronous machine with an open-end stator winding fed by a dual inverter system with a Floating Bridge. The Floating Bridge inverter is used to compensate the reactive power of the main inverter and, hence, to maximize the active power delivered to the motor in compliance with the constraints of a limited current and voltage. The DC-link voltage of the Floating Bridge varies depending on the operating condition of the motor in order to reduce the switching losses and ensure the controllability of the system. The experimental results show that a significant improvement in the width of the speed range at constant power is achievable in the flux weakening region.

  • control scheme for open ended induction motor drives with a Floating capacitor Bridge over a wide speed range
    IEEE Transactions on Industry Applications, 2017
    Co-Authors: Michele Mengoni, Angelo Tani, Giovanni Serra, Luca Zarri, Albino Amerise, Domenico Casadei
    Abstract:

    An electric drive for high-speed applications is analyzed in this paper. The drive consists of a dual two-level inverter with a Floating Bridge, fed by a single voltage source, and a three-phase induction motor with open-ended stator windings. The Floating Bridge compensates the reactive power of the motor, so that the main inverter operates at unity power factor and fully exploits its current capability. The constant power speed range of the motor can be significantly extended depending on the dc-link voltage of the Floating inverter. The details of the control system are examined and the feasibility of an electric drive is experimentally assessed.

  • robust control of an open ended induction motor drive with a Floating capacitor Bridge over a wide speed range
    European Conference on Cognitive Ergonomics, 2016
    Co-Authors: Michele Mengoni, Angelo Tani, Giovanni Serra, Luca Zarri, Albino Amerise, Domenico Casadei
    Abstract:

    An electric drive for high-speed applications is analyzed in this paper. The drive consists of a dual two-level inverter with a Floating Bridge, fed by a single voltage source, and a 3-phase induction motor with open-ended stator windings. The Floating Bridge compensates the reactive power of the motor, so that the main inverter operates at unity power factor and fully exploits its current capability. The constant power speed range of the motor can be significantly extended depending on the DC-link voltage of the Floating inverter. The details of the control system are examined and the feasibility of an electric drive is experimentally assessed.

  • Control of an open-ended induction machine using a dual inverter system with a Floating capacitor Bridge
    2015 IEEE Energy Conversion Congress and Exposition (ECCE), 2015
    Co-Authors: Michele Mengoni, Angelo Tani, Gabriele Rizzoli, Giovanni Serra, Luca Zarri, Domenico Casadei
    Abstract:

    A speed control scheme is proposed for a 3-phase induction motor that uses an open-ended stator winding fed by a dual inverter system with a Floating Bridge. The Floating Bridge has a voltage boosting function that extends the constant power high-speed range of the induction machine and operates the main inverter Bridge at unity power factor. The proposed control scheme coordinates the two inverters that supply the motor, regulates the dc-link voltage of the Floating Bridge and boosts the machine terminal voltage at high speed. Simulation results are used to clarify the motor-drive torque capability in the high speed region. Experimental results show that a significant power improvement is achievable in the field weakening region.

Halvor Lie - One of the best experts on this subject based on the ideXlab platform.

  • A Time-Domain Method for Hydroelasticity of a Curved Floating Bridge in Inhomogeneous Waves
    Journal of Offshore Mechanics and Arctic Engineering, 2018
    Co-Authors: Wei Wei, Torgeir Moan, Chunhui Song, Shi Deng, Halvor Lie
    Abstract:

    This paper presents a time-domain hydroelastic analysis method for Bridges supported by Floating pontoons in inhomogeneous wave conditions. The inhomogeneous wave effect is accounted for by adopting different wave spectra over different regions along the structure, then the time history of inhomogeneous first-order wave excitation forces on the Floating pontoons can be obtained. The frequency-domain hydrodynamic coefficients are transformed into the time-domain hydroelastic model using Cummins' equations. The linear hydroelastic responses of a curved Floating Bridge with end supports, subjected to irregular waves with spatially varying significant wave heights and peak periods, are investigated. Moreover, sensitive analyses are performed to study the effects of the inhomogeneity on the hydroelastic responses. The primary results indicate that the inhomogeneity of the waves has a significant effect on the dynamic responses of the Floating Bridge.

  • A Time-Domain Method for Hydroelastic Analysis of Floating Bridges in Inhomogeneous Waves
    Volume 9: Offshore Geotechnics; Torgeir Moan Honoring Symposium, 2017
    Co-Authors: Wei Wei, Torgeir Moan, Shi Deng, Halvor Lie
    Abstract:

    Based on the three dimensional potential theory and finite element method (FEM), this paper presented a method for time-domain hydroelastic analysis of a Floating Bridge in inhomogeneous waves. A Floating Bridge in both regular and irregular waves, is taken as a numerical example. This method is firstly validated by the comparisons of the results between frequency domain method and presented time domain method under regular wave condition. Then the hydroeleastic responses of the Floating Bridge in waves with spatially varying significant wave height/peak period are presented, with the purpose to illustrate the feasibility of the proposed method. The primary results at this stage indicate that the inhomogeneity of the waves might affect the structure dynamic responses of the Floating Bridge in waves.