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This study describes the research to improve the performance of motor generator for integrated starter generator (ISG) mounted on ecofriendly vehicles. The ISG must be able to start the engine by high torque at the starting mode and generate electric power at the generating mode. In particular, the existing automotive generator is a field winding alternator of CLAW POLE structure, so wound field synchronous machine (WFSM) was used in early ISG. However, it is difficult to control the starting of WFSM with instantaneous high starting torque required at the start and high field current is applied to field windings to generate the magnetic flux. But high field current generates high heat shortening the life of the device. Therefore, consequent pole wound field synchronous machine (CPWFSM) as a novel structure is proposed in this article. It is possible to generate instantaneous high torque easily at starting because of permanent magnet (PM). In the generating mode, CPWFSM can generate power in a wide operation speed that is proposed by taking advantage of WFSM. CPWFSM consists of consequent pole and field winding in the rotor. So it generates high torque with high responsiveness at starting compared with WFSM and it has the advantage of generating output power using low field current at various speed areas because of PM. Simulation of CPWFSM and WFSM is performed by finite-element method (FEM) of ANSYS Electromagnetic Suite (EM 19.0) software, and the experimental results are compared by the dynamo experiment. [ABSTRACT FROM AUTHOR]

This paper studies the output performance improvement of the spherical multi-degree-of-freedom (multi-DOF) motor. The multi-DOF motor is a motor that is designed to drive in multiple axes. Therefore, it is important that the shape of the motor should be fabricated to enable multi-axis driving when designing the multi-DOF motor. In addition, it is essential to consider the output density characteristics and stability characteristic analysis to reduce the volume of the multi-DOF motor and to operate of the motor in the stable range, respectively. In this paper, the structure and operating characteristics of the spherical multi-DOF motor with dual air gaps are described. In order to improve the output characteristics of the multi-DOF motor, characteristics analysis was performed according to the change of the number of the phases and pole pitch angles, and stability characteristic analysis for stable operation of the multi-DOF motor was performed. [ABSTRACT FROM AUTHOR]

This study proposes an interior permanent magnet (IPM) brushless dc (BLDC) motor design strategy that utilizes BLDC control based on Hall sensor signals. The magnetic flux of IPM motors varies according to the rotor position and abnormal Hall sensor problems are related to magnetic flux. To find the cause of the abnormality in the Hall sensors, an analysis of the magnetic flux density at the Hall sensor position by finite element analysis is conducted. In addition, an IPM model with a notch structure is proposed to solve abnormal Hall sensor problems and its magnetic equivalent circuit (MEC) model is derived. Based on the MEC model, an optimal rotor design method is proposed and the final model is derived. However, the Hall sensor signal achieved from the optimal rotor is not perfect. To improve the accuracy of the BLDC motor control, a rotor position estimation method is proposed. Finally, experiments are performed to evaluate the performance of the proposed IPM-type BLDC motor and the Hall sensor compensation method. [ABSTRACT FROM AUTHOR]

This paper discusses a motor that was designed to satisfy the size constraints of system by using ferrite magnet and has the same performance as rare-earth magnet motor. In general, the size of the motor is increased in order to meet the same performance of motor using a ferrite magnet, because of its very low energy density compared to the rare-earth magnet. In order to compensate for these drawbacks, spoke structures capable of generating maximum magnetic flux at the same rotor size have been frequently studied. However, the spoke type motor structure has a drawback that demagnetization occurs in a magnet-specific portion. However, because it affects harmonics of the airgap flux density by demagnetization, it affects mechanical torque ripple and vibration. Therefore, in this paper, the changed air-gap flux density due to the demagnetization phenomenon and the changed mechanical vibration are analyzed by the finite-element method. In addition, we proposed an optimal rotor structure that can reduce the demagnetization phenomenon of magnets in spoke interior permanent magnet synchronous motor. Experiments were performed to evaluate the reliability of the optimized design. [ABSTRACT FROM AUTHOR]

A method is presented to determine the detailed design of a 150 kW-class interior permanent-magnet synchronous motor. The basic designs of stator and rotor were determined, after dividing the designed models into the best and worst cases on the basis of the rotor-shaped parameters. First, the three-bridge basic model satisfying the structural (mechanical) safety factor of the rotor is proposed. The three-bridge basic model does not meet the required torque at rated and maximum speed compared to the no-bridge model. Therefore, it is necessary to perform the design analysis through the selection of various design parameters. However, it is hard and takes alot of time to perform an analysis with numerous shape parameters. Therefore, design parameters with the greatest effect on torque and induced voltage are found using the sensitivity analysis. And the 3-D voltage–inductance map parameters were analyzed. Then, the design of the final model was predicted. On the basis of this prediction, the final model was extracted with a trend analysis. Finally, the final model was validated with experiments. [ABSTRACT FROM AUTHOR]

In this paper, a changeable winding brushless DC (BLDC) motor for the expansion of the speed region is described. The changeable winding BLDC motor is driven by a large number of phase turns at low speeds and by a reduced number of turns at high speeds. For this reason, the section where the winding changes is very important. Ideally, the time at which the windings are to be converted should be same as the time at which the voltage changes. However, if this timing is not exactly synchronized, a large current is generated in the motor, and the demagnetization of the permanent magnet occurs. In addition, a large torque ripple is produced. In this paper, we describe the demagnetization of the permanent magnet in a fault situation when the windings change, and we suggest a design process to solve this problem. [ABSTRACT FROM AUTHOR]

In this paper, we analyze the vibration and noise characteristics of the basic and skewed models of permanent brushless direct current (BLDC) motor. The electromagnetic characteristics of the basic model are analyzed by the finite-element method. We analyzed the electromagnetic characteristics for skew angles from 15° to 25°. The skew angle was selected based on the analytical results of the electromagnetic characteristics. We analyzed the characteristics of radial force density for the basic model and the skewed model. The vibration and noise characteristics were analyzed through the mechanical harmonic analysis of the radial force and tangential force generated in the motor. We developed the basic and skewed models, and performed vibration and noise tests. The validity of this analysis is verified by comparing the simulation results with the actual test results of the model. Finally, for the optimal design of the BLDC motor considering vibration, the design variables such as teeth shoe length, yoke thickness, and teeth thickness were used. Based on the results of vibration analysis, the final model is derived and its performance is described. [ABSTRACT FROM AUTHOR]

Unlike the existing bar-type permanent magnets, it is difficult to magnetize the ferrite spoke-type permanent magnet synchronous motor (PMSM), because the permanent magnet is placed deep inside the shaft. In order to magnetize permanent magnet, a high magnetic field intensity is required. However, the high magnetic field intensity may cause demagnetization of surrounding permanent magnets. It has a bad effect on the magnetization of the permanent magnet and the performance of the spoke-type PMSM. In this paper, we proposed magnetizer models for magnetization of spoke-type 10 pole rotor and the inter-pole winding to reduce the demagnetization of surrounding permanent magnets. Finally, the optimally designed model was manufactured and the performance of the magnetizer was verified. [ABSTRACT FROM AUTHOR]

This paper presents a four-element X-band phased-array transmitter in \0.13-\mu\ m CMOS. The design is based on the all-RF architecture and contains a 5-bit phase shifter (lowest bit is used as a trim bit), 4-bit gain control (to reduce the rms gain error), and power amplifiers capable of delivering a PSAT of \13.5 dBm per channel at 8.5–10.5 GHz. The chip can be used in the linear mode for communication systems and in the saturated mode for frequency-modulated continuous-wave radar systems, and therefore, extensive analysis is done on the phase shifter distortion versus input power. Spectral regrowth and error vector magnitude measurements indicate that the chip can support at least 20-MSym/s quadrature phase-shift keying and binary phase-shift keying modulation at an output power of +\5 dBm per channel. Packaging techniques based on chip-on-board and quad flat no-lead (QFN) modules have been implemented with the four-channel chip, and both show a nearest neighbor coupling of -\ 30 dB at 8–10 GHz, limited by bond-wire coupling. The chip dimensions are \2.9\times \3.0 mm^2 and it consumes 870 mW from 2- and 3-V power supplies. [ABSTRACT FROM PUBLISHER]

This paper presents the design and analysis of an improved wideband in-phase/quadrature (I/Q) network and its implementation in a wideband phased-array front-end. It is found that the addition of two resistors (Rs) in the all-pass I/Q network results in improved amplitude and phase performance versus capacitance loading and frequency, which is essential for wideband millimeter-wave applications. A prototype 60–80-GHz phased-array front-end based on 0.13-\mu\ m SiGe BiCMOS is demonstrated using the improved quadrature all-pass filter and with 4-bit phase-shifting performance at 55–80 GHz. Application areas are in wideband millimeter-wave systems. [ABSTRACT FROM PUBLISHER]

This paper presents a 16-element Q-band transmit/receive phased array with high receive linearity and low power consumption. The design is based on the all-RF architecture with passive phase shifters and a 1:16 Wilkinson network. An input P1{dB} from -\9 to -\10 dBm and a noise figure of 10–11.5 dB at 44–46 GHz is achieved in the receive mode with a power consumption of 0.95 W. In the transmit mode, each channel has an output P1{dB} of 3–2 dBm and Psat of 6–4 dBm at 44–46 GHz with a power consumption of 1.16 W. The design results in a low root mean square (rms) gain error due to a high-resolution variable gain amplifier in each channel. Measurements on multiple channels show near-identical gain and phase response in both the transmit and receive mode due to the use of a symmetrical passive combiner. The measured on-chip coupling is <-\ 40 dB and results in insignificant additional rms and phase error. [ABSTRACT FROM AUTHOR]

This paper presents a 0.01–8-GHz 4\,\times\,4 switch matrix in 0.13-\mu\ m CMOS technology. A deep n-well series–shunt–series switch is chosen as the switching core, and the transistor sizes are optimized for low insertion loss and high isolation up to 8 GHz. Full electromagnetic analysis is also performed on the switching core to result in a compact design. The 4\,\times\,4 switch matrix shows a measured insertion loss of 2.0–3.3 dB and an isolation of 50–44 dB at 2–8 GHz with near-zero power consumption. The measured input P1~{dB} and IP3 are 8–10 and 26–30 dBm at 0.5–8 GHz. The switch matrix has very low dispersion with < \ 6-ps group-delay variation and can switch a 12.5-Gb/s signal with a bit error rate of < \10^-12. The design can be used in reconfigurable 0.01–8 GHz communication systems or as a crossbar switch matrix for data routing. [ABSTRACT FROM PUBLISHER]