Hybrid Excited Synchronous Machine Research Articles

Research on Innovative Hybrid Excited Synchronous Machine

This paper presents research on an unconventional electric machine. It is a hybrid excited machine which includes the features of three types of machines: the Permanent Magnet Synchronous Machine, the Synchronous Machine, and the Synchronous Reluctance Machine. Therefore, a broad literature review related to the above-mentioned types of machines was constructed. The well-known Permanent Magnet assisted Synchronous Reluctance Machine joins features of Permanent Magnet Synchronous Machine and Synchronous Reluctance Machine topologies. This paper shows the results of the innovative design of the Hybrid Excited Permanent Magnet assisted Synchronous Reluctance Machine, which additionally has advantages of the Synchronous Machine. In the article the basic methods of electromagnetic flux control and the designs using them are also presented. Finally, the results of simulation studies of the effect of the stator skew on the machine performance are described.

Design and analysis of a hybrid-excited wound field synchronous machine with high reluctance torque utilization

The paper proposes a hybrid-excited wound field synchronous machine (HE-WFSM), which can achieve high reluctance torque utilization. The key of the proposed HE-WFSM is that two permanent magnets (PMs) assist each rotor pole in forming an additional magnetic flux circle. It is opposite to the magnetic flux circle along the q-axis in the WFSM. The reduction of the q-axis flux can help to improve the saliency ratio and reluctance torque. Additionally, the asymmetrical flux linkage achieves a closest current phase angle between the maximum field torque and the maximum reluctance torque. To highlight the advantages of the proposed HE-WRSM, a general WFSM was adopted as the basic machine and analyzed under the same operating conditions. All performances of the basic machine and proposed HE-WFSM were predicted using finite element analysis (FEA) in Jmag-Designer. Finally, it was confirmed that the proposed HE-WRSM can achieve high reluctance torque utilization.

Hybrid Excited Synchronous Machine with Wireless Supply Control System

The paper presents an unconventional approach to control the hybrid excited synchronous machine (HESM), which can be used for drives of pure electric vehicles. The hybrid excitation of the additional control coil placed on the rotor of the machine has been realized by the wireless energy transfer system connected with the rotor shaft. Experimental results of back-EMF characteristics obtained on a prototype of HESM were compared with 3-dimentional finite elements analysis (3D-FEA) predictions. This design, despite some additional complications in the power supply system of the machine, simplifies the mechanical construction and reduces the control coil’s losses compared to the construction with the coil placed on the stator.

A Novel Modular Stator Hybrid-Excited Doubly Salient Synchronous Machine With Stator Slot Permanent Magnets

This paper presents a novel modular stator hybrid-excited synchronous machine with stator slot permanent magnets (PMs). By regulating the field current, the magnetic field, and consequently the back electromotive force, as well as the average torque can be controlled. The existence of stator slot PMs alleviates the magnetic saturation and improves the flux regulation ratio. The frozen permeability method is employed to investigate the torque contributions by different magnetic sources. Possible stator and rotor pole combinations are illustrated, and the corresponding electromagnetic performances are evaluated with the finite-element method. It is revealed that 12-stator pole machines with 11- and 13-rotor poles exhibit superior average torque and lower torque ripple due to even-order harmonics elimination. Finally, a prototype with modular stator segments is manufactured to validate the analyses and simulations.

A Hybrid Excited Machine with Flux Barriers and Magnetic Bridges

In this paper, an U-shape flux barrier rotor concept for a hybrid excited synchronous machine with flux magnetic bridges fixed on the rotor is presented. Using 3D finite element analysis, the influence of axial flux bridges on the field-weakening and -strengthening characteristics, electromagnetic torque, no-load magnetic flux linkage, rotor iron losses and back electromotive force is shown. Three different rotor designs are analyzed. Furthermore, the field control characteristics depending on additional DC control coil currents are shown.

A novel rotor design for a hybrid excited synchronous machine

Abstract The paper presents three novel rotor design concepts for a three-phase electric controlled permanent magnet synchronous machine (ECPMS-machine) with hybrid excitation. The influence of magnets and flux-barriers arrangement on the magnetic field distribution and field-weakening characteristics of the machine is examined, based on a three-dimensional finite element analysis (3D-FEA). Moreover, a prototype rotor design based on a new rotor concept with a good field-weakening capability is presented in detail. Finally, the experimental results of no-load back electromotive force (back-EMF) waveforms and field-weakening characteristics versus a control coil current of the machine are reported.

Hybrid excited synchronous machine with flux control possibility

Hybrid excited synchronous machine with flux control possibility

A General Voltage-Behind-Reactance Formulation of a Multivoltage n × 3-Phase Hybrid-Excited Synchronous Machine

The paper describes a general model of a hybrid-excited synchronous machine with multiple voltage levels each generated by a 3 -phase stator system in a voltage-behind-reactance formulation. The different voltage level of each 3 -phase stator system is realized in the same machine design. The rotor is excited through an excitation winding and a permanent magnet. The model incorporates magnetic saturation of the main inductance, magnetic and electric coupling between all phases, and the field winding and a mechanical displacement angle. The cross coupling between q and d axes of the main inductances is included as a constant saliency factor $\alpha$ for all saturation levels. The turn ratio of each 3 -phase stator winding system to another 3 -phase system is also modeled as a constant value. Each 3 -phase system saturates the iron core with a different weighting represented by the number of turns relative to the reference stator system. The proposed model is included in a field-oriented control scheme. Simulations are carried out with requested $\boldsymbol{I_{q,d}}$ and field winding currents to demonstrate model's dynamics, and the results are verified with measurements on a test bench.

Minimum‐copper‐loss control of hybrid excited axial field flux‐switching machine

Hybrid excited axial field flux-switching machine (HEAFFSM) with permanent magnets (PMs) and excitation windings in its stator is a novel hybrid excited flux-switching PM machine. The HEAFFSM combines the advantages of the hybrid excited synchronous machine and flux-switching PM machine. In this study, the topology and operating principles of the HEAFFSM are analysed, and the electromagnetic characteristics (including the winding inductances, flux, and cogging torque) are obtained by the three-dimensional finite-element method. On the basis of the vector control method, the mathematical model of the HEAFFSM is deduced, and the operating performance of the HEAFFSM across its entire operating range is investigated. A new minimum-copper-loss (MCL) control strategy for the HEAFFSM drive system, which can operate in both flux-enhancing and flux-weakening conditions, is proposed and compared with the traditional control. The experimental results demonstrate that the MCL strategy maximises the range of speed regulation while minimises the copper loss of the HEAFFSM drive system. Moreover, the flux-regulation capability and high power/torque density of the HEAFFSM are validated.

Vector Control of a Hybrid Axial Field Flux-Switching Permanent Magnet Machine Based on Particle Swarm Optimization

A hybrid axial-field flux-switching permanent magnet machine (HAFFSPMM) is a novel hybrid excited flux-switching permanent magnet motor, which combines the advantages of the axial-field flux-switching permanent magnet machine and hybrid excited synchronous machine. In this paper, based on the vector control method, the mathematical model of the HAFFSPMM is deduced and the operating performance of the HAFFSPMM in the entire operating region is investigated. A novel control scheme for the HAFFSPMM drive system, including the $i_{d }=0$ and flux-weakening strategy, is proposed. To improve the robustness of the control system, the parameters of the proportional-integral (PI) controller are optimized using the particle swarm optimization (PSO) algorithm. The experimental results demonstrate that the proposed control strategy can maximize the output torque and speed range of the drive system, and the PSO-PI controller can reduce the torque ripple and improve the stability of the control system. Moreover, the strong flux-weakening ability, large load capacity, high power, and torque density of the HAFFSPMM are validated.

Active-Flux-Based Motion-Sensorless Vector Control of Biaxial Excitation Generator/Motor for Automobiles

This paper proposes an active-flux-based motion-sensorless vector-control structure for biaxial excitation generator for automobiles (BEGA) for wide speed-range operation. BEGA is a hybrid-excited synchronous machine having permanent magnets on <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$q$</tex></formula> -axis and a dc excitation on <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$d$</tex></formula> -axis. Using the active-flux concept, the estimated rotor position is given by the sum of the active-flux position and torque angle. The active flux is calculated by subtracting the term <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$L_{q}\overline{i}_{s}$</tex></formula> from the estimated stator-flux vector. The experimental results validate the active-flux principle and show good performance for a speed range of 50–2000 r/min. A method for initial rotor position of BEGA is proposed based on injection of a very short voltage pulse in the machine dc excitation, the method being independent of machine parameters. Experimental results for initial rotor-position estimation proved an accuracy below ten electrical degrees in less than 2-ms test time.