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Peng Wang - One of the best experts on this subject based on the ideXlab platform.
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Design of Archimedes Spiral Antenna to Optimize for Partial Discharge Detection of Inverter Fed Motor Insulation
IEEE Access, 2020Co-Authors: Peng Wang, Kai Zhou, Shakeel Akram, Yidong Chen, Muhammad Tariq NazirAbstract:The partial discharge (PD) in inverter-Fed Motors generated from high frequency and short rise time impulsive voltage are more complex than traditional sinusoidal voltage operated Motors due to the noise initiated from fast switching power electronics devices. Available PD sensors and related technology for DC and sinusoidal voltage cannot be used at repetitive impulsive voltage conditions. This work aims to report the design of antenna with optimized geometry and satisfied parameters to detect PD for impulsive voltage. The antenna is verified and the influence of both impulse voltage parameters and test configuration on PD features are discussed. The envelope detection technique after the filter in the frequency domain was proposed to reduce the complexity and cost of PD test hardware under impulsive voltages with fast rise times. The frequency domain energy of PD from Motor insulation is mainly distributed in the range of 0.6-1.8 GHz. By increasing the amplitude and frequency of input impulsive voltage, the range of PD energy spectrum is enlarged to (1.5-1.8 GHz) and by decreasing input amplitude the PD signal strength decays abruptly. Moreover, the high-frequency distribution of PD energy attenuates more severely with the distance and the electromagnetic energy of PD decays nonlinearly with the increase of propagation distance. Therefore, under the premise of satisfying the safety test, selecting the test distance below 15 cm can ensure that the test results have a high signal-to-noise ratio and signal integrity. The experience reported in this study could provide suggestions for off-line PD measurements for inverter-Fed Motor insulation evaluations for manufacturers.
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Influence of Ambient Humidity on PDIV and Endurance of Inverter-Fed Motor Insulation
2019 IEEE Electrical Insulation Conference (EIC), 2019Co-Authors: Peng Wang, Andrea Cavallini, Yanghao Gu, Qi Wu, Qin Zhang, Jiawei Zhang, Peiyi Li, Ying LiAbstract:This work aims to report the influence of ambient humidity on partial discharge inception voltage (PDIV) and lifetime (endurance) of the insulation for inverter-Fed Motors. The PDIV on polyimide film and rotor bar insulated by NOMEX at sinusoidal voltages with 50 Hz frequency and the endurance tests of inverter-Fed Motor turn insulation under repetitive unipolar impulsive voltages with 10 ns rise time and 200 ns voltage on-time were performed at four relative humidity (RH), i.e. 40%, 60%, 80%, 95%, controlling the ambient temperature at 50 °C. Experimental results show that both the PDIV and endurance decrease significantly with increasing RH. Accordingly, the influence of ambient humidity on the test results should be carefully considered when performing PDIV and endurance tests on the insulation of low-voltage and high-voltage inverter-Fed Motors according to IEC standards.
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Temperature effects on PD statistics and endurance of inverter-Fed Motor insulation under repetitive square wave voltages
2016 IEEE Electrical Insulation Conference (EIC), 2016Co-Authors: Peng Wang, Hongying Xu, Andrea Cavallini, Gian Carlo MontanariAbstract:To study the influence of temperature on partial discharge (PD) statistics and endurance of inverter-Fed Motor insulation, experiments were carried out focusing on enameled wires tested under bipolar repetitive square wave voltages at different temperatures. The PD pattern, delay time, amplitude and life were obtaiaed according to a large amount of test results. Experimental results show that the influence of temperature on PD features depends significantly on the voltage frequency. At low frequency, higher temperature will give rise to more PD events with longer delay time and higher magnitude. At higher frequencies the behavior is significantly different, and the influence of temperature on PD features can be neglected. The endurance test results performed at 10 kHz indicate that, at ambient temperature, PD would be the dominant factor causing insulation breakdown, while at high temperature, the thermal aging plays an important role on the breakdown process and time.
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Comparative study of PD characteristics for inverter-Fed Motor insulation under sinusoidal and repetitive square wave voltage conditions
2016 IEEE International Conference on High Voltage Engineering and Application (ICHVE), 2016Co-Authors: Peng Wang, Hongying Xu, Kai Zhou, Qun ZhouAbstract:The partial discharge (PD) test system is setup based on ultra-high frequency technologies in order to study PD characteristics for inverter-Fed Motor insulation under both sinusoidal and repetitive square wave voltage conditions. Resorting to the system, PD tests are performed on single discharge models made out of enameled wires used in low-voltage inverter-Fed Motor insulation under sinusoidal and repetitive square wave voltages with 200 ns rise times. Experimental results show that repetitive square wave and sinusoidal voltages having same peak-to-peak voltage and frequency can produce PD with significantly different magnitude, phase, and energy distribution as well as endurance lifetime. The PD magnitude and insulation endurance under repetitive square wave voltages show seven times higher and three times shorter than those obtained at sinusoidal voltages. Accordingly, when performing insulation evaluation on inverter-Fed Motors according to standards released by International Electrotechnical Commission, it is recommended to use repetitive square wave voltages and the influence of square wave voltage parameters on PD and endurance test results should be considered carefully.
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The effect of impulsive voltage rise time on insulation endurance of inverter-Fed Motors
2015 IEEE 11th International Conference on the Properties and Applications of Dielectric Materials (ICPADM), 2015Co-Authors: Peng Wang, Andrea Cavallini, Gian Carlo MontanariAbstract:Endurance tests under repetitive impulse voltages should be performed on inverter-Fed Motor insulation to evaluate its insulation performance according to the technical specification (TS) released by the International Electrical Commission (IEC), i.e. IEC TS 60034-18-42. To simplify testing procedures in the application, the TS allows life tests to be performed under sinusoidal waveform, as it assumes that sinusoidal and impulsive voltages will provide comparable results if they have same peak-to-peak voltage and frequency. However, we have found that voltage rise time can have significant effect on PD features in both time and frequency domains, so that if PD are deemed the cause of accelerated aging, rise time must be taken into account and sinusoidal waveform may be not the best choice for accelerated aging procedures which resemble the real stress experienced in service by insulation systems of rotating machines controlled by Pulse Width Modulation (PWM). This study aims at summarize the effect of impulsive voltage rise time on insulation life based on endurance tests on crossed enameled wires used for type I Motors and turn/turn insulation for Type II Motors. Repetitive voltages of 6 rise times (i.e. 50 ns, 200 ns, 1 μs, 16 μs, 200 μs and 500 μs, sinusoidal voltage with same peak-to-peak voltage and frequency) and 3 rise times (i.e. 150 ns, 2 μs and sinusoidal voltage with same peak-to-peak voltage and frequency) are used in the endurance tests on Type I and Type II Motor insulation, respectively. Statistical analysis indicate that, due to the different PD features caused by the impulsive voltage rise time, impulsive voltage rise time can have significant effect on insulation lifetime. Accordingly, when performing endurance tests on high-voltage inverter-Fed Motor insulation, the rise time influence on final life of inverter-Fed Motor insulation should be carefully considered.
Chaohao Kan - One of the best experts on this subject based on the ideXlab platform.
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Improvements of the Starting Performance of A Novel Brushless Doubly-Fed Motor Based on the Composite Coils
Energies, 2019Co-Authors: Zhiwei Ruan, Chaohao Kan, Chenglong Chu, Taian Ren, Qiuming ChenAbstract:Brushless doubly-Fed Motor (BDFM) has well applicable potentials in the speed control driving field due to its excellent speed regulation performance. However, the poor starting performance becomes a shortage that still limits the development and application of wound BDFM. To solve the problem, this paper presents a novel BDFM adopted rotor winding based on the principle of the composite coil. Both the principle of the composite coil and the designed example of the rotor winding are analyzed in detail in this content, and the stator winding designed by the change-pole method is described. The performance of the prototype was tested by simulation and experiments, both results reveal that this method can effectively improve the starting performance of BDFM, the system is simplified, and the stability of it is prompted.
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Design and Research of A New Soft-Starting Brushless Doubly-Fed Motor
2019 22nd International Conference on Electrical Machines and Systems (ICEMS), 2019Co-Authors: Chaohao Kan, Ke Jin, Xichang Bao, Jie ZhengAbstract:The paper proposes a new brushless doubly-Fed Motor (BDFM) that can realize soft starting by only changing winding connection mode, because the soft starting of traditional BDFM, mostly realized by external equipment, require high comprehensive cost and low reliability. The slot combination and the connection mode of stator and rotor windings of the new brushless doubly-Fed Motor is introduced in this paper. The structure of the windings can reduce the starting current of the brushless doubly-Fed Motor, making the mechanical properties hard and realizing soft starting without external equipment. The correctness of the winding connection mode and the superiority of this starting mode is proved through simulation comparison with asynchronous starting.
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The Soft-Starting Method for Brushless Doubly-Fed Motor
2019 22nd International Conference on Electrical Machines and Systems (ICEMS), 2019Co-Authors: Chaohao Kan, Ke Jin, Xichang Bao, Jie ZhengAbstract:There are two sets of windings on the stator of brushless doubly-Fed Motor, which determines its various starting modes. The analysis of the starting performance of the Motor by equivalent circuit shows that the impulse current of asynchronous starting is similar to that of asynchronous Motor, which has large starting current and high synchronization speed. Compared with asynchronous starting, the doubly-Fed starting current is smaller and it’s speed can be stable at natural synchronous speed. In order to further reduce the starting current of the Motor, this paper proposes a soft starting method of brushless doubly-Fed Motor based on flexible wound rotor BDFM. A soft starting Motor is designed in this paper and its wiring mode and working principle are introduced in detail. The simulation results show that the soft-starting method not only reduces the starting current, but also has hard mechanical characteristics during the starting process.
Kai Zhou - One of the best experts on this subject based on the ideXlab platform.
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Design of Archimedes Spiral Antenna to Optimize for Partial Discharge Detection of Inverter Fed Motor Insulation
IEEE Access, 2020Co-Authors: Peng Wang, Kai Zhou, Shakeel Akram, Yidong Chen, Muhammad Tariq NazirAbstract:The partial discharge (PD) in inverter-Fed Motors generated from high frequency and short rise time impulsive voltage are more complex than traditional sinusoidal voltage operated Motors due to the noise initiated from fast switching power electronics devices. Available PD sensors and related technology for DC and sinusoidal voltage cannot be used at repetitive impulsive voltage conditions. This work aims to report the design of antenna with optimized geometry and satisfied parameters to detect PD for impulsive voltage. The antenna is verified and the influence of both impulse voltage parameters and test configuration on PD features are discussed. The envelope detection technique after the filter in the frequency domain was proposed to reduce the complexity and cost of PD test hardware under impulsive voltages with fast rise times. The frequency domain energy of PD from Motor insulation is mainly distributed in the range of 0.6-1.8 GHz. By increasing the amplitude and frequency of input impulsive voltage, the range of PD energy spectrum is enlarged to (1.5-1.8 GHz) and by decreasing input amplitude the PD signal strength decays abruptly. Moreover, the high-frequency distribution of PD energy attenuates more severely with the distance and the electromagnetic energy of PD decays nonlinearly with the increase of propagation distance. Therefore, under the premise of satisfying the safety test, selecting the test distance below 15 cm can ensure that the test results have a high signal-to-noise ratio and signal integrity. The experience reported in this study could provide suggestions for off-line PD measurements for inverter-Fed Motor insulation evaluations for manufacturers.
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Comparative study of PD characteristics for inverter-Fed Motor insulation under sinusoidal and repetitive square wave voltage conditions
2016 IEEE International Conference on High Voltage Engineering and Application (ICHVE), 2016Co-Authors: Peng Wang, Hongying Xu, Kai Zhou, Qun ZhouAbstract:The partial discharge (PD) test system is setup based on ultra-high frequency technologies in order to study PD characteristics for inverter-Fed Motor insulation under both sinusoidal and repetitive square wave voltage conditions. Resorting to the system, PD tests are performed on single discharge models made out of enameled wires used in low-voltage inverter-Fed Motor insulation under sinusoidal and repetitive square wave voltages with 200 ns rise times. Experimental results show that repetitive square wave and sinusoidal voltages having same peak-to-peak voltage and frequency can produce PD with significantly different magnitude, phase, and energy distribution as well as endurance lifetime. The PD magnitude and insulation endurance under repetitive square wave voltages show seven times higher and three times shorter than those obtained at sinusoidal voltages. Accordingly, when performing insulation evaluation on inverter-Fed Motors according to standards released by International Electrotechnical Commission, it is recommended to use repetitive square wave voltages and the influence of square wave voltage parameters on PD and endurance test results should be considered carefully.
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The measurement of space charge in solid insulation of inverter-Fed Motor
2008 International Symposium on Electrical Insulating Materials (ISEIM 2008), 2008Co-Authors: Jun Liu, Guangning Wu, Kai Zhou, Lijun ZhouAbstract:In order to explain the phenomenon of the polymer aged even breakdown under electric stress, the relationship between the space charge and the polymer residual life is studied both in domestic and abroad laboratories. An apparatus that can directly measure the space charge distribution in the polymer insulation materials is developed. Then the space charge distribution in the polymer insulation used in PWM inverter Fed Motors is tested. Effects of different test condition including pole voltage and frequency are investigated in order to find the aging rule and microcosmic behave of the polymer insulation which worked under the PWM voltage.
Pengcheng Nie - One of the best experts on this subject based on the ideXlab platform.
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Research on Brushless Doubly-Fed Motor for Direct-drive Screw Pump
2019 22nd International Conference on Electrical Machines and Systems (ICEMS), 2019Co-Authors: Tantan Zhao, Xuefan Wang, Jinfei Yao, Zhenping Li, Ming Kong, Pengcheng NieAbstract:The Brushless Doubly-Fed Motor (BDFM) is a special machine having some typical characteristics similar to the synchronous machine. Due to absence of brush, commutator and permanent magnet, BDFM can avoid annular fire and permanent magnet demagnetization, which make it more suitable for direct-drive technology of screw pump. Nowadays, there are many control devices are recommended to meet the requirements on the screw pump performance and the reliability in the field of petroleum exploration. In this paper, vector scheme is implemented on running and braking condition of the BDFM for direct-drive screw pump. Simulation results verify the good performance of BDFM in this type of control strategy.
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Asynchronous Starting Characteristics and Soft Start Method of the Brushless Doubly-Fed Motor
2018 21st International Conference on Electrical Machines and Systems (ICEMS), 2018Co-Authors: Nian Liu, Xuefan Wang, Ming Kong, Chenglu Hang, Pengcheng NieAbstract:Based on the steady-state mathematical model of the brush-less double-Fed machine (BDFM), this paper analyzes the mechanical characteristics of the Motor in asynchronous operation mode. In this mode of operation, when the two sets of stator windings of the BDFM are respectively assigned as power winding, they both have characteristics similar to those of the conventional asynchronous Motors with the corresponding pole pairs. And then, a 30 kW BDFM is modeled and simulated by finite element analysis. Finally, based on the above conclusions, an asynchronous soft start method suitable for brushless double-Fed Motor is proposed.
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Asynchronous operation characteristics and soft-starting method for the brushless doubly-Fed Motor
IET Electric Power Applications, 2017Co-Authors: Ming Kong, Xuefan Wang, Pengcheng NieAbstract:The brushless doubly-Fed Motor (BDFM) is versatile and can perform under several modes of operation. Other than the commonly used doubly-Fed mode, BDFM can also operate in an asynchronous mode wherein the control winding of the Motor is short circuited. The proposed study first analysed the mechanical characteristics of BDFM operation under this mode, whereby it was noted that there exist two induction torque components corresponding to different pole pairs within the Motor. The Motor, therefore, behaved as a conventional induction machine. Based on the above analysis and by introducing the concept of equivalent resistance of the machine-side inverter, an asynchronous soft-starting method for BDFM is proposed herein. By switching one side of the inverter bridge arms to the off state and adjusting the duty cycle on the other side, a controllable equivalent resistance is obtained and inserted into the control winding of BDFM. Consequently, the starting characteristic of BDFM can be improved to achieve soft start-up of the Motor. Finally, experiments were conducted on a 30 kW BDFM prototype, of which, the results verify the accuracy of the torque analysis and improved performance of the proposed soft-starting method.
Naoki Hayakawa - One of the best experts on this subject based on the ideXlab platform.
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partial discharge propagation and degradation characteristics of magnet wire for inverter Fed Motor under surge voltage application
Conference on Electrical Insulation and Dielectric Phenomena, 2006Co-Authors: Naoki Hayakawa, Masato Morikawa, H Inano, K Inuzuka, Hitoshi OkuboAbstract:In this paper, we investigated the PD generation, propagation, degradation and breakdown (BD) characteristics of magnet wire for inverter-Fed Motor under surge voltage application. Experimental results revealed the transition of PD activity, i.e. intermittent PD, successive PD, critical PD and BD, under repetitive surge voltage application with a fixed peak value. The transition from intermittent PD to successive PD was associated with the PD propagation along the enamel surface into the lower electric field region. Critical PD was a drastic change of PD activity and identified as the local BD of magnet wire. Since the final BD was confirmed to be always induced at the critical PD location, critical PD was regarded as an important indicator to determine the life of magnet wire for inverter-Fed Motor.
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Partial discharge inception and degradation characteristics of inverter-Fed Motor sample under surge voltage condition
Annual Report - Conference on Electrical Insulation and Dielectric Phenomena CEIDP, 2005Co-Authors: Masato Morikawa, Naoki Hayakawa, Hitoshi OkuboAbstract:Surge voltages with the rise time of the order of nano-seconds may cause partial discharge (PD) and result in the degradation of electrical insulation performance of the inverter-Fed Motor coils. We investigated the PD inception and degradation characteristics of twisted pair samples under surge voltage condition. Experimental results firstly revealed that there existed no obvious correlation between PD inception voltage (PDIV) and the rise time of surge voltage. Secondly, PD propagation and degradation characteristics were also investigated under the higher voltage application, and discussed in terms of charge behavior in air gap and on enamel surface. Finally, we obtained the dependence of time leading to BD on enamel coating thickness of the wire.
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partial discharge characteristics of inverter Fed Motor coil samples under ac and surge voltage conditions
Conference on Electrical Insulation and Dielectric Phenomena, 2003Co-Authors: Hitoshi Okubol, Naoki HayakawaAbstract:This work investigates the partial discharge (PD) characteristics of twisted pair samples for inverter-Fed Motor coil under ac and surge voltage conditions. It also discusses the difference in the PD inception characteristics of a twisted pair under 60-Hz voltage and surge voltages with a steep wave front. The PDIV under ac voltage was measured and was found to agree well with the theoretical value using electric field analysis and Paschen's law. The PDIV under surge voltage was measured for different repetition rates and the PDIV for 60-pps repetition was found to be lower than those for 6 pps and for the single shot, which suggested that the electrical insulation performance would be influenced by the repetition rate. The PDIV under surge voltages was 1.5 to 1.8 and 2.3 to 2.7 times higher than those under AC voltage application for the used and virgin samples, respectively.
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Partial discharge inception characteristics influenced by stressed wire length of inverter-Fed Motor
The 17th Annual Meeting of the IEEE Lasers and Electro-Optics Society 2004. LEOS 2004., 1Co-Authors: Hitoshi Okubo, Masato Morikawa, Naoki HayakawaAbstract:Surge voltages with a rise time of several tens or hundreds of ns in inverter-Fed Motor coils may cause partial discharge (PD) and degradation of electrical insulation performance. We investigated the PD characteristics of inverter-Fed Motor coil samples with different lengths of enamel-coated wire under surge and ac voltage conditions. Experimental results revealed that PD inception voltage (PDIV) decreased with the increase in the wire length, which was evaluated in terms of the stressed wire contact length, i.e. size effect. We proposed a regression line for the size effect on PDIV for the electrical insulation design of inverter-Fed Motor coils.