scholarly journals Comparative Analysis of the Steady-State Model Including Non-Linear Flux Linkage Surfaces and the Simplified Linearized Model when Applied to a Highly-Saturated Permanent Magnet Synchronous Machine—Evaluation Based on the Example of the BMW i3 Traction Motor

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2343
Author(s):  
Michal Gierczynski ◽  
Lech M. Grzesiak
Keyword(s):  
Steady State ◽  
Magnetic Circuit ◽  
Numerical Data ◽  
Vector Model ◽  
Flux Linkage ◽  
Machine Model ◽  
Partial Load ◽  
Torque Curve ◽  
Reference Design ◽  
Linearized Model

This paper presents a finite element method (FEM)-based model, which describes the magnetic circuit of the BMW i3 traction machine. The model has been reconstructed based on data available in the public domain. The reader is provided with numerical data regarding flux linkage surfaces in d- and q-axes, as well as with all the information needed to develop a space-vector model of the machine in steady-state, taking into consideration the non-linearity of the magnetic circuit. Hence, the data of a highly-saturated machine from a renowned product are provided, which can serve as a reference design for research. After that, torque curve and partial load operation points are calculated. Finally, the machine model is linearized and the calculations are repeated with the simplified linearized model. The results from both models are then compared with each other. This comparison is intended to assess the magnitude of the expected inaccuracies, when simplified analytical tools are applied to highly-saturated machines (which are the backbone of automotive electrical drivetrains). It is especially important with regard to preliminary design of electrical drivetrains, as at this stage detailed machine geometry and materials are not known.

Steady-State Unbalance Response of Continuous Rotors on Anisotropic Supports

1993 ◽  
Author(s):  
Graziano Curti ◽  
Francesco A. Raffa ◽  
Furio Vatta
Keyword(s):  
Steady State ◽  
Stiffness Matrix ◽  
Dynamic Stiffness ◽  
Analytical Investigation ◽  
Dynamic Stiffness Matrix ◽  
Rotor Systems ◽  
Beam Elements ◽  
Unbalance Response ◽  
Constant Coefficients ◽  
Linearized Model

Abstract An analytical investigation of the steady-state unbalance response of axisymmetric rotor systems with anisotropic, flexible and damped bearings is presented. According to the exact approach of the dynamic stiffness method, the rotor is modelled by means of continuous beam elements. In this work, the expression of the 8 × 8 dynamic stiffness matrix of a rotating Timoshenko beam is derived and it is shown that it is related, by means of a simple law, to the previously published 4 × 4 dynamic stiffness matrix, which holds for the isotropic bearings case. The effects of concentrated disks and bearings are included into the formulation; in particular, each bearing is described by eight constant coefficients, according to the well-known linearized model of the bearing forces. The unbalance response of a typical rotor system taken from the literature is analyzed. A comparison is presented with the finite element results reported by other authors.

Study on Off-Design Steady State Performances of Helium Gas Turbocompressor for HTGR-GT

2006 ◽  
Author(s):  
Qisen Ren ◽  
Xiaoyong Yang ◽  
Zhiyong Huang ◽  
Jie Wang
Keyword(s):  
Steady State ◽  
High Temperature ◽  
Electric Power ◽  
Gas Turbine ◽  
Thermal Power ◽  
Power Adjustment ◽  
Partial Load ◽  
Helium Gas ◽  
Gas Turbine Cycle ◽  
High Temperature Gas

The high temperature gas-cooled reactor (HTGR) coupled with direct gas turbine cycle is a promising concept in the future of nuclear power development. Both helium gas turbine and compressor are key components in the cycle. Under normal conditions, the mode of power adjustment is to control total helium mass in the primary loop using gas storage vessels. Meanwhile, thermal power of reactor core is regulated. This article analyzes off-design performances of helium gas turbine and compressors for high temperature gas-cooled reactor with gas turbine cycle (HTGR-GT) at steady state level of electric power adjustment. Moreover, performances of the cycle were simply discussed. Results show that the expansion ratio of turbine decreases as electric power reduces but the compression ratios of compressors increase, efficiencies of both turbine and compressors decrease to some extent. Thermal power does not vary consistently with electric power, the difference between these two powers increases as electric power reduces. As a result of much thermal energy dissipated in the temperature modulator set at core inlet, thermal efficiency of the cycle has a widely reduction under partial load conditions.

scholarly journals Partial Inductance Model of Induction Machines for Fault Diagnosis

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2340 ◽  
Author(s):  
Manuel Pineda-Sanchez ◽  
Ruben Puche-Panadero ◽  
Javier Martinez-Roman ◽  
Angel Sapena-Bano ◽  
Martin Riera-Guasp ◽  
...  
Keyword(s):  
Magnetic Circuit ◽  
Induction Machines ◽  
The Self ◽  
Magnetic Vector Potential ◽  
Diagnostic Systems ◽  
Magnetic Vector ◽  
Machine Model ◽  
Stator Current ◽  
Novel Approach ◽  
Short Circuits

The development of advanced fault diagnostic systems for induction machines through the stator current requires accurate and fast models that can simulate the machine under faulty conditions, both in steady-state and in transient regime. These models are far more complex than the models used for healthy machines, because one of the effect of the faults is to change the winding configurations (broken bar faults, rotor asymmetries, and inter-turn short circuits) or the magnetic circuit (eccentricity and bearing faults). This produces a change of the self and mutual phase inductances, which induces in the stator currents the characteristic fault harmonics used to detect and to quantify the fault. The development of a machine model that can reflect these changes is a challenging task, which is addressed in this work with a novel approach, based on the concept of partial inductances. Instead of developing the machine model based on the phases’ coils, it is developed using the partial inductance of a single conductor, obtained through the magnetic vector potential, and combining the partial inductances of all the conductors with a fast Fourier transform for obtaining the phases’ inductances. The proposed method is validated using a commercial induction motor with forced broken bars.

Inductance Measurement for PMSM Using Instantaneous Flux Linkage Method

2014 ◽  
Vol 685 ◽  
pp. 393-396
Author(s):  
Yan Ling Cao ◽  
Ping Cao ◽  
Yan Dong Wen
Keyword(s):  
Steady State ◽  
Performance Analysis ◽  
Measurement Method ◽  
Decoupling Control ◽  
Flux Linkage ◽  
Control Torque ◽  
Torque Estimation ◽  
Linkage Method ◽  
Ac Current ◽  
Steady State Performance

The dq-axis inductances are important for the voltage decoupling control, torque estimation and steady-state performance analysis of a PMSM machine. In this paper, a measurement method is proposed based on the dq-axis instantaneous flux linkages calculation. The rotor is locked by a positive d-axis current, and then a proper AC current is assigned respectively to the d and q-axis reference current in order to cover the various current ranges. The instantaneous flux linkages are calculated by the integration of dq-axis current and voltage offline. Finally, dq-axis inductances are computed by the integrated flux linkages divided by the dq-axis current.

Heat Transfer Normal to Paired Arterioles and Venules Embedded in Perfused Tissue During Hyperthermia

1988 ◽  
Vol 110 (4) ◽  
pp. 277-282 ◽  
Author(s):  
C. K. Charny ◽  
R. L. Levin
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Three Dimensional ◽  
Numerical Data ◽  
Tissue Temperature ◽  
Three Dimensional Model ◽  
Sources And Sinks ◽  
The Mean ◽  
Krogh Cylinder ◽  
Subsequent Incorporation

A numerical model of the heat transer normal to an arteriole-venule pair embedded in muscle tissue has been constructed. Anatomical data describing the blood vessel size, spacing, and density have been incorporated into the model. This model computes temperatures along the vessel walls as well as the temperature throughout the tissue which comprises an infinitely long Krogh cylinder around the vessel pair. Tissue temperatures were computed in the steady-state under resting conditions, while transient calculations were made under hyperthermic conditions. Results show that for both large- (1st generation) and medium-sized (5th generation) vessel pairs, the mean tissue temperature within the tissue cylinder is not equal to the mean of the arteriole and venule blood temperatures under both steady-state and transient conditions. The numerical data were reduced so that a comparison could be made with the predictions of a simple two-dimensional superposition of line sources and sinks presented by Baish et al. [1]. This comparison reveals that the superposition model accurately describes the heat transfer effects during hyperthermia, permitting subsequent incorporation of this theory into a realistic three-dimensional model of heat transfer in a whole limb during hyperthermia.

scholarly journals Core Flow Distribution from Coupled Supercritical Water Reactor Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Po Hu ◽  
Paul P. H. Wilson
Keyword(s):  
Steady State ◽  
Supercritical Water ◽  
Power Distribution ◽  
Reactor Core ◽  
Flow Distribution ◽  
Core Model ◽  
Core Flow ◽  
The Core ◽  
Extended Code ◽  
Reference Design

This paper introduces an extended code package PARCS/RELAP5 to analyze steady state of SCWR US reference design. An 8 × 8 quarter core model in PARCS and a reactor core model in RELAP5 are used to study the core flow distribution under various steady state conditions. The possibility of moderator flow reversal is found in some hot moderator channels. Different moderator flow orifice strategies, both uniform across the core and nonuniform based on the power distribution, are explored with the goal of preventing the reversal.

Control Performance Analysis of SR S/G System Based on FEM

2012 ◽  
Vol 246-247 ◽  
pp. 801-805
Author(s):  
Shou Jun Song ◽  
Man Zhang ◽  
Wen Jie Liu ◽  
Ze Xiu Han
Keyword(s):  
Steady State ◽  
Dynamic Simulation ◽  
Performance Optimization ◽  
Parametric Method ◽  
Strong Nonlinearity ◽  
Control Performance ◽  
Switched Reluctance ◽  
Reluctance Machine ◽  
Torque Curve ◽  
Steady State Simulation

Switched reluctance machine (SRM) has many outstanding advantages, and can be widely used in many electromechanical applications. However, it’s relatively difficult to analyze the control performance of SRM due to strong nonlinearity of the electromagnetic field. In this paper, the performance of SRM is analyzed by finite element method (FEM). Firstly, the simulation model of a 4-phase 8/6 pole SRM is built, and then the steady-state and dynamic simulation are carried out. In steady-state simulation, the magnetization and torque characteristics are obtained by parametric method. In dynamic simulation, the performance, include current and torque curve, under both motoring and generating mode are given. The simulation and analysis results are useful for performance optimization of SRM.

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