Influence of Frequency on Electromagnetic Field of Super High-Speed Permanent Magnet Generator

Qiu, Hongbo,Wei, Yanqi,Wang, Wei,Tang, Bingxia,Zhao, Xifang,Yang, Cunxiang The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.4

When compared with traditional power frequency generators, the frequency of a super high-speed permanent magnet generator (SHSPMG) is a lot higher. In order to study the influence of frequency on the electromagnetic field of SHSPMGs, a 60000rpm, 117kW SHSPMG was taken as a research object. The two-dimensional finite element model of the generator was established, and the two-dimensional transient field of the generator was simulated. In addition, a test platform of the generator was set up and tested. The reliability of the simulation was verified by comparing the experiment data with that of the simulation. Then the generator electromagnetic field under different frequencies was studied, and the influence mechanism of frequency on the generator electromagnetic field was revealed. The generator loss, voltage regulation rate, torque and torque ripple were analyzed under the rated active power load and different frequencies. The influences of frequency on the eddy current density, loss, voltage regulation rate and torque ripple of the generator were obtained. These conclusions can provide some reference for the design and optimization of SHSPMGs.

Influence of Inter-turn Short-Circuit Fault Considering Loop Current on Electromagnetic Field of High-Speed Permanent Magnet Generator with Gramme Ring Windings

Hongbo Qiu,Xifang Zhao,Cunxiang Yang,Yi Ran,Yanqi Wei 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.2

As a kind of emergency power supply in military fi eld, the high-speed permanent magnet generator (HSPMG) has attracted wide attention to its healthy condition. The loop current (LC) of the inter-turn short-circuit (ITSC) fault seriously endangers the generator unit operation stability and power supply reliability. In order to study the infl uence of pulsating magnetic fi eld produced by LC on the electromagnetic fi eld, the two-dimensional fi nite element model (FEM) of the 117 kW, 60000 rpm HSPMG is established. By comparing calculation result and test data, the accuracy of the model is verifi ed. The fi eld-circuit coupling method is used to reveal the change mechanism of magnetic fi eld symmetry when ITSC fault occurs. By comparing the spatial distribution of the air-gap fl ux density, the relationship among the spatial distribution of the air-gap fl ux density, the elliptical rotating magneto-motive force (MMF) and the current phase angle is determined. The variation of the amplitude of the air-gap fl ux density space harmonic under diff erent fault degree is studied, and the fault characteristics of ITSC fault are obtained, which provides a reference for ITSC fault diagnosis and fault degree identifi cation. In addition, the research also laid a theoretical foundation for the next analysis of the loss and temperature fi eld.

Correction to: Research on the Infl uences of Time Harmonics on Permanent Magnet Synchronous Motors with Hybrid Magnet Poles

Hongbo Qiu,Yuedong Guo,Wenfei Yu,Bingxia Tang,Cunxiang Yang 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.4

Research on the Influences of Time Harmonics on Permanent Magnet Synchronous Motors with Hybrid Magnet Poles

Hongbo Qiu,Yuedong Guo,Wenfei Yu,Bingxia Tang,Cunxiang Yang 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.3

With the development of electric electron technology and controlling technology, controller for driving permanent magnet synchronous motors is used widely. The using of a controller can expand the motor speed range and improve motor runtime performances. However, the output current of a controller contains lots of time harmonics that will have bad infl uences on motor torque and losses. In order to analyze the infl uences of the time harmonics on the motor performances, diff erent time harmonic currents were injected into the motor armature. Taking a 750 W, 250 r/min permanent magnet synchronous motor with hybrid magnet poles (HPPMSM) as an example, the 2-D fi nite model was established. On this basis, the torque ripple and eddy current losses of permanent magnets with diff erent time harmonics were obtained. The infl uences of time harmonics on motor torque ripple and eddy current losses were determined, and the impacting mechanism was revealed. The analyses may be helpful for the optimal design of HPPMSM.

Influence of Sleeve Material and Sleeve Composite Structure on Performance of High-Speed Permanent Magnet Starter-Generator for Micro-Gas Turbine

Qiu Hongbo,Liu Ziyang,Xiong Bin,Zhao Qiang,Dong Yu,Wu Xuandong 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.4

When the high-speed permanent magnet starter-generator (PMSG) is operating, the permanent magnets will be aff ected by high centrifugal forces. It is necessary to add a sleeve to protect the rotor and interference fi t with the permanent magnet. However, the performance of the high-speed PMSG will be signifi cantly infl uenced by the electromagnetic characteristics of the sleeve material. In this paper, a high-speed permanent magnet starter-generator for the micro-gas turbine is used as an example, and the two-dimensional fi nite element model is established. The correctness of the model is verifi ed by comparing the experimental data with the calculated data. Taking 10,000 r/min as the ignition speed, the diff erences of motor starting performances when using diff erent sleeve materials are compared. Secondly, decoupling the complex coupling torque in the starting process, the infl uence of material electromagnetic characteristics on the asynchronous torque and braking torque is determined, and the infl uence mechanism of material electromagnetic characteristics on the torque characteristics of highspeed PMSG is revealed. In addition, the eff ects of the sleeve materials on the output performance and loss of the high-speed PMSG are determined, and infl uence mechanism is revealed. On the basis, a sleeve multiplexing scheme is proposed to improve the starting performance while reducing the eddy current losses in the generating state. The results of the study provide reference and theoretical value for the optimization of high-speed permanent magnet starter-generator.

Influence of Magnetic Slot Wedge on Parameter and Loss Distribution of High Voltage Induction Motor

Qiu Hongbo,Wang Kun,Liu Ziyang,Xiong Bin,Wu Xuandong 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.6

Owing to the stator open slot structure of the high-voltage motor, the magnetic field distribution in the motor will be uneven, and the performance of the motor will deteriorate. When the slots are embedded with magnetic material slot wedges, the magnetic field of the motor will be changed. In this article, taking a 10 kV/1000 kW high-voltage induction motor (HVIM) as the prototype, the two-dimensional finite element models are established, the eff ect of magnetic slot wedge (MSW) on HVIM was analyzed. First, by establishing the air-gap permeance function, the infl uence of magnetic slot wedge on the air gap magnetic field is analyzed, the influence mechanism of magnetic slot wedge on tooth harmonic magnetic field is revealed. In addition, the effect of magnetic slot wedge on excitation inductance, slot leakage resistance, and winding inductance of HVIM is analyzed in detail, the variation of parameters with different relative permeability of slot wedge is summarized, the changes in the motor starting performance had further discussed. Finally, the influence of the slot wedge permeability on motor losses is studied, the distribution of core loss is obtained by establishing the motor segmenting model, and the various mechanisms of core losses in different regions are revealed. The findings provide the guidelines and theoretical basis for the rational selection of magnetic slot wedges.

Influence of Different Frequency Harmonic Generated by Rectifier on High-speed Permanent Magnet Generator

Qiu, Hongbo,Wei, Yanqi,Yang, Cunxiang,Fan, Xiaobin The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

Since the stator winding of High-Speed Permanent Magnet Generator (HSPMG) has few winding turns and low inductance value, it is more prone to be influenced by harmonic current. Moreover, the operation efficiency and the torque stability of HSPMG will be greatly influenced by harmonic current. Taking a 117 kW, 60 000 rpm HSPMG as an example, in order to analyze the effects of harmonic current on HSPMG in this paper, the 2-D finite element electromagnetic field model of the generator was established and the correctness of the model was verified by testing the generator prototype. Based on the model, the losses and torque of the generator under different frequency harmonic current were studied. The change rules of the losses and torque were found out. Based on the analysis of the influence of the harmonic phase angle on torque ripple, it is found that the torque ripple could be weakened through changing the harmonic phase angle. Through the analysis of eddy current density in rotor, the change mechanism of the rotor eddy current loss was revealed. These conclusions can contribute to reduce harmonic loss, prevent demagnetization fault and optimize torque ripple of HSPMG used in distributed power supply system.

Influence of Different Frequency Harmonic Generated by Rectifier on High-speed Permanent Magnet Generator

Hongbo Qiu,Yanqi Wei,Cunxiang Yang,Xiaobin Fan 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.5

Since the stator winding of High-Speed Permanent Magnet Generator (HSPMG) has few winding turns and low inductance value, it is more prone to be influenced by harmonic current. Moreover, the operation efficiency and the torque stability of HSPMG will be greatly influenced by harmonic current. Taking a 117 ㎾, 60 000 rpm HSPMG as an example, in order to analyze the effects of harmonic current on HSPMG in this paper, the 2-D finite element electromagnetic field model of the generator was established and the correctness of the model was verified by testing the generator prototype. Based on the model, the losses and torque of the generator under different frequency harmonic current were studied. The change rules of the losses and torque were found out. Based on the analysis of the influence of the harmonic phase angle on torque ripple, it is found that the torque ripple could be weakened through changing the harmonic phase angle. Through the analysis of eddy current density in rotor, the change mechanism of the rotor eddy current loss was revealed. These conclusions can contribute to reduce harmonic loss, prevent demagnetization fault and optimize torque ripple of HSPMG used in distributed power supply system.

Research on the Influence of Inter-turn Short Circuit Fault on the Temperature Field of Permanent Magnet Synchronous Motor

Qiu, Hongbo,Yu, Wenfei,Tang, Bingxia,Yang, Cunxiang,Zhao, Haiyang The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.8 No.1

When the inter-turn short circuit (ITSC) fault occurs, the distortion of the magnetic field is serious. The motor loss variations of each part are obvious, and the motor temperature field is also affected. In order to obtain the influence of the ITSC fault on the motor temperature distribution, firstly, the normal and the fault finite element models of the permanent magnet synchronous motor (PMSM) were established. The magnetic density distribution and the eddy current density distribution were analyzed, and the mechanism of loss change was revealed. The effects of different forms and degrees of the fault on the loss were obtained. Based on the loss analysis, the motor temperature field calculation model was established, and the motor temperature change considering the loop current was analyzed. The influence of the fault on the motor temperature distribution was revealed. The sensitivity factors that limit the motor continuous operation were obtained. Finally, the correctness of the simulation was verified by experiments. The conclusions obtained are of great significance for the fault and high temperature demagnetization of the permanent magnet analysis.

Research on the Influence of Inter-turn Short Circuit Fault on the Temperature Field of Permanent Magnet Synchronous Motor

Hongbo Qiu,Wenfei Yu,Bingxia Tang,Cunxiang Yang,Haiyang Zhao 대한전기학회 2017 Journal of Electrical Engineering & Technology Vol.12 No.4

When the inter-turn short circuit (ITSC) fault occurs, the distortion of the magnetic field is serious. The motor loss variations of each part are obvious, and the motor temperature field is also affected. In order to obtain the influence of the ITSC fault on the motor temperature distribution, firstly, the normal and the fault finite element models of the permanent magnet synchronous motor (PMSM) were established. The magnetic density distribution and the eddy current density distribution were analyzed, and the mechanism of loss change was revealed. The effects of different forms and degrees of the fault on the loss were obtained. Based on the loss analysis, the motor temperature field calculation model was established, and the motor temperature change considering the loop current was analyzed. The influence of the fault on the motor temperature distribution was revealed. The sensitivity factors that limit the motor continuous operation were obtained. Finally, the correctness of the simulation was verified by experiments. The conclusions obtained are of great significance for the fault and high temperature demagnetization of the permanent magnet analysis.