Rotor Synchronous Machine Research Articles

Multimaterial filtering applied to the topology optimization of a permanent magnet synchronous machine

PurposeThis study aims to propose a general methodology to handle multimaterial filtering for density-based topology optimization containing periodic or antiperiodic boundary conditions, which are expected to reduce the simulation time of electrical machines. The optimization of the material distribution in a permanent magnet synchronous machine rotor illustrates the relevance of this approach.Design/methodology/approachThe optimization algorithm relies on an augmented Lagrangian with a projected gradient descent. The 2D finite element method computes the physical and adjoint states to evaluate the objective function and its sensitivities. Concerning regularization, a mathematical development leads to a multimaterial convolution filtering methodology that is consistent with the boundary conditions and helps eliminate artifacts.FindingsThe method behaves as expected and shows the superiority of multimaterial topology optimization over bimaterial topology optimization for the chosen test case. Unlike the standard approach that uses a cropped convolution kernel, the proposed methodology does not artificially reflect the limits of the simulation domain in the optimized material distribution.Originality/valueAlthough filtering is a standard tool in topology optimization, no attention has previously been paid to the influence of periodic or antiperiodic boundary conditions when dealing with different natures of materials. The comparison between the bimaterial and multimaterial topology optimization of a permanent magnet machine rotor without symmetry constraints constitutes another originality of this work.

Fast and accurate methodologies for the eddy current losses analysis in axially laminated rotor of synchronous reluctance machines under different loads

AbstractThe authors present two fast and accurate methodologies for the computation of eddy current losses in the axially laminated rotor of a synchronous reluctance machine. The methodologies are based on different combinations of the finite element method in time and frequency domains with 2D and 3D formulations. First, a comparative study of the 2D and 3D formulations for loss calculation is presented, considering various load angles of the machine to illustrate the problem of eddy‐current losses in this type of machines and its dependence on the load angle. The influence of the iron saturation on the loss calculation is also evaluated in these computations. A novel correction factor based on the computations at two load angles is proposed to convert the losses computed from a 2D model to match those computed from a 3D model. For the sake of generality, investigations are also conducted for various thicknesses of the lamination layers and different machine lengths, and an analytical method to describe the dependency of eddy‐current losses on the load angle of the machine is introduced. Moreover, a simplified method is proposed for modelling eddy currents in the frequency domain and calculating losses in an axially laminated structure based solely on the results of a magnetostatic solution. The results obtained by the simplified model demonstrate excellent agreement with the full 3D magneto‐dynamic simulation. Overall, the findings contribute to understanding and accurately characterising the eddy current losses in axially laminated rotors, offering potential insights for designing and optimising axially laminated synchronous reluctance electric machines.

Analysis and investigation of synchronous machine rotor winding short-circuit fault in a distribution system

Analysis and investigation of synchronous machine rotor winding short-circuit fault in a distribution system

High-Speed Synchronous Reluctance Machine Rotor Using Multi-Material Additive Manufacturing

High-Speed Synchronous Reluctance Machine Rotor Using Multi-Material Additive Manufacturing

Design and Verification of an Electrically Excited Synchronous Machine Rotor with Direct Oil Cooling for Truck Applications

Design and Verification of an Electrically Excited Synchronous Machine Rotor with Direct Oil Cooling for Truck Applications

Combined Dimensional and Topology Optimization of Synchronous Machine Rotors Using a Material Density Interpolation Method

Combined Dimensional and Topology Optimization of Synchronous Machine Rotors Using a Material Density Interpolation Method

Optimization of material distribution applied to magnet-free rotors of synchronous motors

In a relentless desire to continuously improve the performance of electric actuators, topological optimal design methods present interesting possibilities. In particular, this work applies an optimization approach of material distribution in order to define new configurations of material arrangements (air, steel, copper) for internal parts of machines, that potentially provide better performance. This methodology is applied to different design configurations of magnet-free synchronous machine rotors.

Coil-Processing of CFRP Bandages for Rotors of High-Speed Synchronous Electric Machines with Permanent Magnets

Coil-Processing of CFRP Bandages for Rotors of High-Speed Synchronous Electric Machines with Permanent Magnets

Novel Double Mode Dual-Stator Wound Rotor Synchronous Machine for Variable Speed Applications

This paper offers a novel dual-mode double stator wound rotor synchronous machine for variable speed applications. The proposed motor integrates the benefits of both the traditional wound rotor synchronous machine (WRSM) and brushless wound rotor synchronous machine (BL-WRSM). A constant torque can be attained in the maximum torque per ampere region by operating the proposed machine as a traditional WRSM in Mode I, and a constant power can be attained in the field-weakening region by operating it as a BL-WRSM in Mode II. Moreover, due to the dual-stator structure, the proposed machine exhibits improved performance in terms of high torque density as compared to the existing single stator BL-WRSM. By using a special stator winding arrangement to achieve the sub-harmonic component of the stator magnetomotive force, the brushless operation of the proposed machine is achieved. The additional sub-harmonic component induces a voltage in the harmonic winding placed on the rotor, which is then rectified and provided a DC current to field winding for brushless excitation. In order to validate the effectiveness of the proposed machine, a two-dimensional finite element analysis (FEA) is carried out.

Evaluation of the Rotor Mechanical Stresses and Electromagnetic Parameters of a Permanent Magnet Electric Machine

Electric machines with permanent magnets incorporated into the rotor have broad prospects for use in applications characterized by an increased rotational speed of the electromechanical converter. The method of placing permanent magnets on the electromechanical converter’s rotating part has an essential influence on the rotor mechanical strength and the machine’s electromagnetic performance. The article discusses ways to reduce mechanical stresses in the synchronous machine rotor with V-shaped permanent magnets. Preliminary assessment of stresses was made using a simplified analytical model. Based on the obtained results, configuration options for permanent magnets and rotor pole pieces were selected. A distribution pattern of mechanical loads on the external and internal saturation bridges was obtained using a finite element analysis, which refines and confirms the approximate analytical results. The rotor design has been optimized with respect to the criterion of achieving the minimum of maximal stresses in the saturation bridges. The angle between permanent magnets on the pole and the fillet radius at the permanent magnet to pole piece junction locations are chosen as independent parameters. The proposed solutions have been verified from the viewpoint of ensuring the required magnetic induction value in the gap, and the angular characteristics have been calculated. Based on the obtained theoretical study results, a prototype synchronous motor with a rotor containing V-shaped permanent magnets has been designed and manufactured, and its tests have been carried out.

On-Line Rotor Ground Fault Location Method for Brushless Synchronous Machines

The detection of ground faults in the rotor of brushless synchronous machines is usually a difficult task due to the absence of available measurements. This paper presents a new on-line rotor ground fault location method for brushless synchronous machines. The proposed method is able to detect and locate a ground fault in the excitation system without removing the rotor for testing. The method is based on the measurement of the exciter field current and on the analysis of a voltage. This voltage is measured at a high ohmic grounding resistor installed between the neutral of the exciter armature and ground through a slip ring. The method has been validated by computer simulations and by experimental tests using a special laboratory setup, obtaining excellent results.

A fast data-driven topology identification method for dynamic state estimation applications

This paper proposes a fast topology identification method to avoid estimation errors caused by network topology changes. The algorithm applies a deep neural network to determine the switching state of the branches that are relevant for the execution of a dynamic state estimator. The proposed technique only requires data from the phasor measurement units (PMUs) that are used by the dynamic state estimator. The proposed methodology is demonstrated working in conjunction with a frequency divider-based synchronous machine rotor speed estimator. A centralized and a decentralized approach are proposed using a modified version of the New England test system and the Institute of Electrical and Electronics Engineers (IEEE) 118-bus test system, respectively. The numerical results in both test systems show that the method demonstrate the reliability and the low computational burden of the proposed algorithm. The method achieves a satisfactory speed, the decentralized approach simplifies the training process and the algorithm proves to be robust in the face of wrong input data.

Magneto-Structural Combined Dimensional and Topology Optimization of Interior Permanent Magnet Synchronous Machine Rotors

A magneto-structural combined dimensional and topology optimization approach for interior permanent magnet synchronous machine (IPMSM) rotor design is proposed using the solid isotropic material with penalization (SIMP) density-based topology optimization method. This method optimizes the location and dimensions of the permanent magnets (PMs) embedded in the rotor, while simultaneously optimizing the lamination flux barriers using topology optimization. To allow for the location and dimensions of the PMs to change a Laplace smoothing mesh deformation technique is used. Three examples of IPMSM rotor optimizations are presented to demonstrate the proposed approach. In addition, a geometric template-based optimization is carried out for a comparison to one of the dimensional and topology optimized examples to better illustrate the difference.

USE OF T-SHAPED TOOTH IN A DIRECT CURRENT MACHINE WITH A WINDLESS ROTOR

The electric direct current machine with a windingless rotor (DCWR) is significantly different from the classic direct current machine; its magnetic system does not have a common yoke and consists of a number of magnetically loose teeth and grooves open on both sides. The presence of grooves in which there is no bottom creates a number of air gaps, which leads to a decrease in the magnetic conductivity of the magnetic conductor in the transverse direction, which, again, leads to a weakening of the reaction field of the Фa armature and the rejection of additional poles and compensation winding. Therefore, the size of the working air gap can be reduced to the minimum possible value from a technological point of view. According to the structural schemes, the DCWR belongs to the type of induction machines with two stationary windings on the stator and a toothed magnetic conductor of the rotor, in which the magnetic induction in the working air gap changes only in magnitude without changing the sign. Therefore, the rotor in the DCWR is not remagnetized and is made of ordinary structural steel. The inductor type of the magnetic system allows having only one, common for all poles, excitation winding in the DCWR, and the rotor is very similar to the rotor of multi-pole synchronous machines with permanent incorporated magnets. At the same time, DCWR does not have permanent magnets, which allows to significantly reduce the cost of an electric machine. Replacing straight teeth with T-shaped ones allows you to significantly increase the efficiency of the DCWR design by improving its heat dissipation. The results of calculations and modeling of the stationary thermal field presented in the article show that the use of T-shaped teeth allows you to significantly increase the overload capacity of the DCWR or increase its power.

Comparative study on torque characteristics of permanent magnet synchronous reluctance motors with different axial hybrid rotors

An axial hybrid permanent magnet synchronous reluctance machine (AHPM-SynRM) is proposed in this paper. The structure is a combination of synchronous reluctance rotor and two permanent magnet rotors. The proposed design includes three axially parallel rotors, the reluctance axis coincides in phase with the permanent magnet axis by rotating the synchronous reluctance machine (SynRM) rotor, which could increase the average torque. In the condition of the volume of permanent magnets stays unchanged, the relationship between the axial length ratio of different rotor parts and the maximum torque is also analyzed. Moreover, air gap magnetic isolation is designed between each rotor part, so there is no serious magnetic field coupling between different rotors and each rotor part could be separately designed. The analysis results prove the proposed machine has significantly higher torque performance than the permanent magnet assisted machine. (PM-SynRM).

Absolutely Feasible Synchronous Reluctance Machine Rotor Barrier Topologies with Minimal Parametric Complexity

The first step in the synchronous reluctance machine design is the selection of rotor flux barrier type. The literature provides various barrier construction methods with a common goal of reducing parametric complexity. However, too excessive simplification can lead to decreased performance, while overly complex geometries tend to increase optimization time. This paper presents a set of novel flux barrier construction methods with an increased degree of freedom and minimal geometrical complexity. The paper proposes four topologies based on circular, hyperbolic, and original Zhukovsky lines. When considering parametrization complexity, the original Zhukovsky type is the simplest, but it has barrier depth limitations. Other topologies have equal complexity. The paper proposes a novel Modified Zhukovsky variable depth type based on geometrical conformal mapping of the original Zhukovsky lines. The step-by-step construction of each topology is presented in a form of pseudo-code with detailed comments and illustrations. Overall, the presented research provides a valuable starting point for the designer who wants to investigate different smooth rotor barrier topologies.

Simulation based of DC-DC Converter for AVR System and PID Controller with Tree Seed Algorithm based AVR System for Synchronous Generator

The voltage is supervised by AVR an automatic voltage regulator. It transforms the varying voltage into a constant voltage. The most prevalent cause of voltage fluctuation is changes in load on the supply system. An excitation system is a system that provides the necessary field current to the synchronous machine's rotor winding. The most important characteristics of an excitation system are dependability under all operating circumstances, ease of control, and ease of maintenance, stability, and quick transient response. In the literature, several control systems, such as in the literature, PID controllers, adaptive control methods, and intelligent control methods have all been suggested. On the one hand to get an accurate and quick generator terminal voltage control, the usage of a step down chopper in the exciter circuit is suggested in this study. DC-DC converters are also called as Choppers. The Step down chopper, It changes a given DC input voltage into a determined DC output voltage The input voltage source is tie up with governable solid state device that acts as a switch. Switches can be made using metal oxide semiconductor field effect transistors (MOSFETs) or insulated gate bipolar transistors (IGBT). The field circuit of the generator is associated to the chopper and a Praportional-Intigral controller deviates the converter duty cycle to vary the generator's terminal voltage. to regulate the generator field voltage. On the other hand, Tree-Seed Algorithm (TSA) algorithm based PID controller is put forward for automatic voltage regulator system. The suggested approach calculates PID coefficients to the best of its ability. The execution of this TSA-based optimum PID controller is compared to that of various PID controllers produced in the literature utilizing different meta-hermetic optimization techniques. Comparative research in for the suggested schemes has a superior transient response and is more resistant to fluctuations in Generator load and DC input voltage.

ВПЛИВ РЕЖИМНИХ І ЕКСПЛУАТАЦІЙНИХ ФАКТОРІВ НА ДЕМПФЕРНУ СИСТЕМУ РОТОРА ЯВНОПОЛЮСНОЇ СИНХРОННОЇ МАШИНИ

The physical processes in the damping system of the salient-pole synchronous machine rotor, which cause the gradual destruction of its structure, have been studied. In particular, the distributions of currents, temperatures and thermomechanical stresses in the damping system rods during its operation in asynchronous and asymmetric modes of operation, as well as in case of rotor eccentricity. A field mathematical model has been developed that takes into account the combined action of three physical fields of different nature: electromagnetic, temperaturic, and thermomechanical stress fields, and allows estimating heating and thermomechanical loads in the damping system of the rotor of the salient-pole synchronous machine. According to the results of the analysis, the heating and thermomechanical loads of the structural elements were determined and recommendations for its structural improvement were given. References 9, figures 9, tables 1.

About the kinetic energy of mutual motion of synchronous machine rotors under disturbance in a large power system

The article shows the analysis of the components of the mutual motion of the synchronous machines rotors in the transient process under disturbance conditions. It is shown that the representation of the original EPS can be represented by a two-machine equivalent, relative to the section in which stability is violated.

A Hybrid-Learning Algorithm for Online Dynamic State Estimation in Multimachine Power Systems.

With the increasing penetration of distributed generators in the smart grids, having knowledge of rapid real-time electromechanical dynamic states has become crucial to system stability control. Conventional Supervisory Control and Data Acquisition (SCADA)-based dynamic state estimation (DSE) techniques are limited by the slow sampling rates, while the emerging phasor measurement units (PMUs) technology enables rapid real-time measurements at network nodes. Using generator bus terminal voltages, we propose a hybrid-learning DSE (HL-DSE) algorithm to estimate the synchronous machine rotor angle and speed in real time. The HL-DSE takes the power system model into account and trains neuroestimators with real-time data in an online manner. Compared with traditional DSE methods, the HL-DSE overcomes limitations by using a data-driven approach in conjunction with the physical power system model. The time efficiency, accuracy, convergence, and robustness of the proposed algorithm are tested under noises and fault conditions in both small- and large-scale test systems. Simulation results show that the proposed HL-DSE is much more computationally efficient than widely used Kalman filter (KF)-based methods while maintaining comparable accuracy and robustness. In particular, HL-DSE is over 100 times faster than square-root unscented KF (SR-UKF) and 80 times faster than extended KF (EKF). The advantages and challenges of the HL-DSE are also discussed.