Wound Rotor Synchronous Motor Research Articles

Influence of D-Q Current on No-Insulated High-Temperature Superconducting Magnets for Wound-Rotor Synchronous Motors

Influence of D-Q Current on No-Insulated High-Temperature Superconducting Magnets for Wound-Rotor Synchronous Motors

Performance Analysis of Permanent Magnet Synchronous Motor for Mining Applications – A Review

The features of Permanent Magnet Synchronous Motor (PMSM) makes it suitable for mining applications such as copper mining, mining floating machine, mining scraper conveyor, mine integrated machine, mining vacuum circuit breaker, mineral extraction in mines, coal mine belt conveyor system, mining truck and many more. This study focuses on performance analysis of permanent magnet synchronous motor for mining applications and performance analysis is the confirmation and analysis of parameters, various losses and efficiency at various loads. A comparative analysis of wound rotor synchronous motor, induction motor and permanent magnet synchronous motor confirmed the suitability of PMSM for various mining applications. Advanced technology of artificial intelligence integrated with permanent magnet synchronous motor also enhances the effectiveness and precision of the system.

Thermal analysis methods for wound rotor synchronous motors with water-cooling jackets

A thermal equivalent circuit (TEC) was presented as an effective thermal analysis method for a wound rotor synchronous motor (WRSM) with a water-cooling jacket. The effectiveness of the TEC analysis was verified by comparison with the results of the experiments and numerical analysis. The steady-state temperature obtained from the TEC matched well with those obtained from the experiments and numerical analysis. The transient temperature variation in each part of the WRSM estimated by the TEC was in good agreement with the experimental results. Therefore, TEC can easily estimate the temperature information of the WRSM.

Comparative Study of Induction and Wound Rotor Synchronous Motors for the Traction Drive of a Mining Dump Truck Operating in Wide Constant Power Speed Range

Comparative Study of Induction and Wound Rotor Synchronous Motors for the Traction Drive of a Mining Dump Truck Operating in Wide Constant Power Speed Range

Wound Rotor Synchronous Motor as Promising Solution for Traction Applications

Traction applications, such as electric and hybrid vehicles, require the electrical motor to be operated at low load conditions during most of their driving cycle. Permanent magnet (PM) motors in this case may not be an optimal choice due to their poor efficiency under low load conditions despite the fact that they exhibit the best output characteristics at the rated load. However, the wound rotor synchronous motor (WRSM) demonstrates the best efficiency at low load conditions due to their controllable excitation. This paper presents an interesting comparison of WRSM and the PM motor in terms of their efficiency over the entire drive cycle of traction applications, which demonstrates that WRSMs are more suitable compared to the apparently best performance PM motor. A WRSM with similar dimensions to the 2010 Toyota Prius interior permanent synchronous motor (IPMSM) was designed and optimized in this regard. The performance comparison of the PM motor and the WRSM was presented using 2-D finite element analysis (FEA) for the WRSM and the performance analysis report of the Toyota Prius IPMSM published by the US department of energies. The FEA analysis shows that the WRSM can achieve wide torque speed characteristics. Moreover, the WRSM exhibits better efficiency under low load conditions at the higher speed or field weakening region.

A novel two-layer winding topology for sub-harmonic synchronous machines

With optimized design and modern brushless operation, wound rotor synchronous machines are resurrecting as a strong contender in many applications presently dominated by permanent magnet machines. Considering the notion, this paper introduces a novel brushless synchronous machine topology that utilizes sub-harmonic magnetomotive force (MMF) of its stator winding for desirable brushless operation. It is significant to state that the sub-harmonic MMF component that is used in this novel topology is one-fourth of the fundamental MMF component, whereas, in previous practices, it was half. Moreover, the stator of the machine uses a new winding arrangement of two sets of balanced three-phase windings wound in two layers to produce the fundamental and the sub-harmonic MMF. To achieve the brushless excitation, the rotor utilizes an additional winding that is used to induce the electromotive force (EMF) by the sub-harmonic MMF component of the stator. This novel two-layer stator winding topology permits the utilization of maximum allowable space in the stator to house conductors in all of its 48 slots, which was not the case in previous papers. To validate the performance, and feasibility, an 8-pole 48-slot brushless wound rotor synchronous motor is designed, and a 2-D finite element analysis simulation is conducted, where the topology shows immense potential in terms of better torque performance.

Comparative Performance Evaluation of Wound Rotor Synchronous Motor and Interior Permanent Magnet Synchronous Motor with Experimental Verification

Comparative Performance Evaluation of Wound Rotor Synchronous Motor and Interior Permanent Magnet Synchronous Motor with Experimental Verification

Sensorless Control of Wound Rotor Synchronous Motors Based on Rotor High-Frequency Signal Injection

High-frequency (HF) signal injection-based has been widely investigated for sensorless position/speed control of permanent magnet synchronous machines (PMSMs). In PMSMs, the HF signal must be injected in the stator windings and an asymmetric (salient) rotor is required. The extension of HF injection-based sensorless methods with wound-rotor synchronous motors is studied in this article. The fact that rotor terminals are accessible opens interesting possibilities, as avoids the dependency on rotor asymmetries.

Comparison of Electrified Aircraft Propulsion Drive Systems with Different Electric Motor Topologies

Electric aircraft propulsion is a growing research area that looks into achieving propulsion through fully electric or hybrid electric systems while achieving low emissions. The system-level benefit gained by different electric and hybrid-electric propulsion schemes depends heavily on the performance of system-level components in the electric drive-train, including the electric motor, gear box, motor drive, protection systems, as well as the thermal management system. When comparing motor topologies, it is important to understand performance measures such as efficiency and specific power on a drive system level. Many different motor types have been qualitatively compared and can be found in the literature. To guide appropriate component selection, this paper presents details of a quantitative study for a given electric propulsion drive system. A Pareto optimal front for a notional drive system of a 1.5 MW electrical propulsor with different motor types is generated and compared. An optimization algorithm coupled with an electromagnetic finite element analysis software tool was used to optimize the induction motor, switched reluctance motor, wound rotor synchronous motor, permanent magnet synchronous motor (PMSM), slotless PMSM, permanent-magnet-assisted synchronous reluctance motor, brushless DC motor, and brushless doubly fed reluctance motor types for efficiency and specific power. Overall advantages considering system-level efficiency, specific power, and a few other key metrics such as origin of losses, cooling complexity, manufacturing tolerance, and fault tolerance are discussed. This gives an indication of the relative performance of different motor types and confirms the overall advantage of PM motor topologies in aircraft propulsion.

A New Small-Scale Self-Excited Wound Rotor Synchronous Motor Topology

In this article, a new low-cost small-scale three-phase brushless motor topology is proposed. This is a new topology for self-excitation of brushless wound rotor synchronous motor investigated initially for rated speed. For brushless excitation, the stator is designed to contain two windings, namely, three-phase armature winding and exciter winding. The rotor consists of two windings, that is, harmonic winding and field winding, and a diode rectifier. An inverter feeds the three-phase armature winding which is connected in series through an uncontrolled three-phase rectifier to a single exciter winding. When the current is supplied from the inverter, both the armature and exciter windings are energized eventually producing a flux in the air gap. Since the flux produced by the exciter winding is not synchronized with the field winding, it produces a harmonic to be intercepted by the harmonic winding on the rotor. Eventually, the voltage produced in the harmonic winding is used to feed dc current to the field winding for brushless operation. The results obtained by 2-D finite-element analysis (FEA) validate the brushless operation of the motor. The proposed motor is analyzed basically for topology verification with the FEA results. Since the topology can be verified, further effort can be put to investigate such low-cost topologies for brushless wound rotor synchronous motor. It can be an alternative to a costly permanent magnet synchronous motor for specific applications.

Model Parameter and Performance Calculation of Cylindrical Wound-Rotor Synchronous Motors

The paper details modern saturation modeling and performance calculation to the analysis of grid-connected cylindrical wound-rotor synchronous motors. The developed models give reliable results with limited computation effort. The finite element based method uses iterative procedures to calculate the motor performance during which the motor parameters are evaluated in detail. Experimental results prove that the method has a high degree of accuracy and is computationally efficient.

Field Current Control Strategy for Wound-Rotor Synchronous Motors Considering Coupled Stator Flux Linkage

The direct axis (d-axis) stator winding and field winding of a wound-rotor synchronous motor (WRSM) are mutually coupled much like the primary and secondary windings in a transformer are. As the field winding has a large number of turns, small variations of the stator d-axis current can induce a great electromotive force (EMF) in the field windings. This induced EMF voltage disturbs field current regulation, invokes an unwanted field current response, and distorts the stator d-axis flux. In this work, a novel field current control strategy for the WRSM is proposed for compensating the disturbance by d-axis current in field winding. The coupling effect between the stator d-axis winding and field winding is analyzed by using a polynomial regression of the stator d-axis flux linkage. Based on an analysis of the coupling effect, the proposed strategy combines two control methods. First, feedforward control is applied to decouple the field current response from the coupled change in the stator d-axis current flux. Second, a method is used to adjust the d-axis current to ensure that the field inverter voltage is not saturated. Simulations and experiments are presented to verify the proposed control method, proving that the proposed field current control strategy successfully compensates for the field current ripples caused by variations in the coupled stator d-axis current flux.

Self-Sensing Control of Wound Rotor Synchronous Motor Drive for Mine Hoist

Control of a wound rotor synchronous motor (WRSM) drive for a mine hoist has to address specific properties. One of them is reliable and safe operation without sensor of the rotor position. To fulfill this requirement, we propose a sensorless vector control allowing drive operation with maximum available torque. The proposed sensorless rotor position estimation utilizes natural ac components of the rotor field excitation current. This component acts as a modulation signal, which has measurable effect on the stator currents and can be used to estimate the actual position of the rotor. We investigate two techniques for identification of the rotor position: The phase-lock loop and the extended Kalman filter. Both techniques are able to estimate the rotor position and magnetic polarity. However, the Kalman filter offers faster convergence and higher accuracy. It is able to provide reliable rotor position estimation in the whole speed range of the drive. Proper function of the introduced control algorithm is verified by simulations and experiments made on a developed small-scale prototype of a mine hoist drive of rated power of 10 kW.

Current Control of WRSM Considering Magnetic Saturation Phenomenon

This paper introduces the characteristics of a 120 kW class wound rotor synchronous motor (WRSM) considering the effects of magnetic saturation in electrical steel. The flux linkage due to the rotor windings and the $d$ -axis inductance of WRSM vary non-linearly because of the magnetic saturation. This affects the selection of a current combination for maximum torque per ampere (MTPA) control. The relation between the current combination for MTPA control and magnetic saturation is analyzed in this paper. Finding a current combination that satisfies the requirements is very difficult, because WRSM has complicated current combinations ( $i_{f}$ , $i_{d}$ , and $i_{q})$ . Therefore, an algorithm for the calculation of the optimal current is proposed using the Lagrange function, and the current map is presented. Finally, the validation of the selected current combination is performed through the comparison of the results of an experiment and the finite-element analysis.

An Off-line Maximum Torque Control Strategy of Wound Rotor Synchronous Machine with Nonlinear Parameters

Belt-driven Starter Generator (BSG) differs from other mild hybrid systems as the crankshaft of vehicle are not run off. Motor permits a low-cost method of adding mild hybrid capabilities such as start-stop, power assist, and mild levels of regenerative braking. Wound rotor synchronous motor (WRSM) could be adopted in BSG system for HEV e-Assisted application instead of the interior permanent magnet synchronous motor (IPMSM). In practice, adequate torque is indispensable for starter assist system, and energy conversion should be taken into account for the HEV or EV as well. Particularly, flux weakening control is possible to realize by adjusting both direct axis components of current and field current in WRSM. Accordingly, this paper present an off-line current acquisition algorithm that can reasonably combine the stator and field current to acquire the maximum torque, meanwhile the energy conversion is taken into consideration by losses. Besides, on account of inductance influence by non-uniform air gap around rotor, nonlinear inductances and armature flux linkage against current variation are proposed to guarantee the results closer to reality. A computer-aided method for proposed algorithm are present and results are given in form of the Lookup table (LUT). The experiment shows the validity of algorithm.

Generic optimal control of synchronous motors

This paper presents one generic optimal current control that can be applied to all types of synchronous motors: interior permanent magnet synchronous motors, wound rotor synchronous motor and hybrid excitation synchronous motor. The control aims to meet the torque and speed requirements while insuring minimal losses. The main contribution of the work is that analytical expressions for the optimal reference currents are computed with respect to armature current limit in addition to armature voltage constraint. Another contribution is that the proposed optimisation algorithm is extended to include the iron losses, too, which cannot be done easily using the standard control method. Simulation proves that the presented control yields indeed to the solution with minimum losses.

48V 계자 권선형 동기전동기 고성능 자속기반 토크제어

In this paper, High performance torque control based on the flux mapping of 48V Wound Rotor Synchronous Motor has been studied to improve torque control. Flux map considering MTPA (Maximum Torque Per Ampere), MFPT (Minimum Flux Per Torque), Maximum efficiency point at the same torque command and flux command for each field current was produced. Current map using flux mapping of Each field current was applied to the MTPA, MFPT. Generating a current vector locus was to determine the characteristics of the operation region. Through the Matlab/Simulink simulation, difference between speed-torque map and flux map was represented. The suggested flux map was tested actual experiments on a dynamometer.

A ZCS buck excitation converter for electric vehicle with wound rotor synchronous motors

In this paper, a high power density zero-current switching (ZCS) Buck excitation converter for electric vehicle (EV) with wound rotor synchronous motors is proposed. To eliminate the pulse noises in excitation current when considering the parasitic parameters for the rotor coil, a small coupled inductor and a small resonant capacitor are combined with basic Buck circuit. Owing to the existence of resonance, zero-current soft-switching for both turn-on and turn-off transitions is achieved, and more importantly, a constant output current without any spikes is guaranteed, which contributes to efficiency promotion and electromagnetic interference (EMI) reduction. Since no large-sized output filters or resonant components are adopted, the volume of the converter is minimised. In the end, PSIM simulation results are presented to verify the feasibility of theoretical analysis.

Circuits of a pulse-vector controlling alternate current motor drive

A system of classification for methods for pulse-vector controlling ac drives is presented. The resource and energy efficiency are considered in electric drives using pulse-vector control systems with wound rotor induction and synchronous motors. Various examples of pulse-vector control circuits are discussed. The control principles for each circuit are worked out, and instances of their application are given. The choice of the element basis of these circuits is grounded, and the advantages and disadvantages of each circuit are considered. The basic pulse-vector control circuits are compared in terms of the following parameters: the values of the maximum electromagnetic torque for the nominal motor torque and the torque pulses for the nominal motor torque. It is shown that application of pulse-vector control improves the energy- and cost-effectiveness of the electric drive, while using different circuits allows one to eliminate some of its disadvantages.

계자전류 조합에 따른 ISG용 권선형 동기전동기의 설계 및 특성분석

In this paper, design of Wound Rotor Synchronous Motor(WRSM) for Integrated Starter and Generator(ISG) is performed based on Finite Element Analysis(FEA). WRSM can control not only magnitude and phase of armature current, but also field current. Thus, various control methods can be considered. Since driving characteristic of WRSM depends greatly on the control method, characteristic analysis accoding to possible driving current combination is reguired. Especially in high speed region, the control method that reduces unnecessary d-axis current by reducing field current is possible, which is similar to field weakening control. By the current combination reducing field and d-axis current, the design minimizing copper loss to increase efficiency on identical driving point is possible. In this paper, high efficient WRSM is designed applying the current combination which can minimize copper loss on each driving point.