Zero Frequency

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform

G Poddar - One of the best experts on this subject based on the ideXlab platform.

  • medium voltage vector control induction motor drive at Zero Frequency using modular multilevel converter
    IEEE Transactions on Industrial Electronics, 2018
    Co-Authors: Yerraguntla Shasi Kumar, G Poddar
    Abstract:

    Conventional modular multilevel converter (MMC) has severe limitation to operate at low Frequency for the application of variable-speed induction motor drive. Fluctuation of submodule (SM) capacitor voltage increases rapidly as the motor speed decreases with rated torque. Finally, it becomes impractical to operate the motor at Zero Frequency. Recently, MMC-based medium voltage induction motor drive has been proposed to tackle this problem without additional circulating current. However, it does not solve the problem near Zero Frequency with nonZero motor torque. This paper proposes new method to solve this problem of high peak-to-peak voltage ripple of SM capacitor at all frequencies including Zero Frequency. Vector control strategy for induction motor is adopted here to have accurate control of torque near Zero Frequency. First, the problem of low-Frequency operation is analyzed. Then, the solution is proposed analytically. The proposed control technique and overall performance of the drive have been verified through experimental results.

S. Okuma - One of the best experts on this subject based on the ideXlab platform.

  • New approach for stability improvement of speed- sensorless induction-motor controls at Zero Frequency using multirate adaptive observer
    IEE Proceedings - Electric Power Applications, 2006
    Co-Authors: N. Yamaguchi, Masaru Hasegawa, S. Doki, S. Okuma
    Abstract:

    The paper describes a new approach to improve the stability of speed-sensorless vector-controlled induction motors at Zero-Frequency operation. In the speed-sensorless vector control of induction motors, speed identification based on a fundamental-component model becomes unstable at Zero-Frequency operation. At Zero Frequency, the stator voltage and the stator current of induction motors are both direct current, and speed information cannot be obtained from them. The speed identification thus becomes unstable at Zero Frequency if disturbances such as parameter mismatches, noises and measurement errors affect the speed identification system. The paper proposes a method of improving the stability in the speed identification of speed-sensorless vector-controlled induction motors at Zero Frequency by means of a new configuration of the adaptive flux observer. A review of this problem is carried out, namely that speed identification becomes unstable at Zero Frequency, and it is shown that this problem originates in an unstable pole-Zero cancellation in the speed-identification system. A new observer configuration with a multirate input control is proposed and the results of experiments carried out to confirm the effectiveness of the proposed method are given.

  • A stabilization method for speed sensorless vector controlled induction motors at Zero Frequency operating condition with multirate adaptive observer
    30th Annual Conference of IEEE Industrial Electronics Society 2004. IECON 2004, 2004
    Co-Authors: N. Yamaguchi, Masaru Hasegawa, S. Doki, S. Okuma
    Abstract:

    This paper proposes a stabilization method for speed sensorless vector controlled induction motors at Zero Frequency operating condition using a new configuration of the adaptive observer. In speed sensorless vector controlled induction motors, it has been pointed out that the speed identification system becomes unstable at Zero Frequency operating condition. This problem is caused by lack of the knowledge of the rotor side of induction motors, and the disturbance such as a parameter mismatch of the stator quantities at Zero Frequency operating condition. In this paper, a new configuration of the adaptive observer, which stabilizes speed sensorless vector control of induction motors without injecting a high Frequency or an excitation signal, is proposed. Firstly, causes of unstable speed identification in the conventional speed sensorless vector control system are considered. Next, a configuration of the adaptive observer based on multirate control in order to stabilize the speed sensorless system at Zero Frequency operating condition is proposed. Finally, validity of the proposed method is shown by experimental results.

Yerraguntla Shasi Kumar - One of the best experts on this subject based on the ideXlab platform.

  • medium voltage vector control induction motor drive at Zero Frequency using modular multilevel converter
    IEEE Transactions on Industrial Electronics, 2018
    Co-Authors: Yerraguntla Shasi Kumar, G Poddar
    Abstract:

    Conventional modular multilevel converter (MMC) has severe limitation to operate at low Frequency for the application of variable-speed induction motor drive. Fluctuation of submodule (SM) capacitor voltage increases rapidly as the motor speed decreases with rated torque. Finally, it becomes impractical to operate the motor at Zero Frequency. Recently, MMC-based medium voltage induction motor drive has been proposed to tackle this problem without additional circulating current. However, it does not solve the problem near Zero Frequency with nonZero motor torque. This paper proposes new method to solve this problem of high peak-to-peak voltage ripple of SM capacitor at all frequencies including Zero Frequency. Vector control strategy for induction motor is adopted here to have accurate control of torque near Zero Frequency. First, the problem of low-Frequency operation is analyzed. Then, the solution is proposed analytically. The proposed control technique and overall performance of the drive have been verified through experimental results.

N. Yamaguchi - One of the best experts on this subject based on the ideXlab platform.

  • New approach for stability improvement of speed- sensorless induction-motor controls at Zero Frequency using multirate adaptive observer
    IEE Proceedings - Electric Power Applications, 2006
    Co-Authors: N. Yamaguchi, Masaru Hasegawa, S. Doki, S. Okuma
    Abstract:

    The paper describes a new approach to improve the stability of speed-sensorless vector-controlled induction motors at Zero-Frequency operation. In the speed-sensorless vector control of induction motors, speed identification based on a fundamental-component model becomes unstable at Zero-Frequency operation. At Zero Frequency, the stator voltage and the stator current of induction motors are both direct current, and speed information cannot be obtained from them. The speed identification thus becomes unstable at Zero Frequency if disturbances such as parameter mismatches, noises and measurement errors affect the speed identification system. The paper proposes a method of improving the stability in the speed identification of speed-sensorless vector-controlled induction motors at Zero Frequency by means of a new configuration of the adaptive flux observer. A review of this problem is carried out, namely that speed identification becomes unstable at Zero Frequency, and it is shown that this problem originates in an unstable pole-Zero cancellation in the speed-identification system. A new observer configuration with a multirate input control is proposed and the results of experiments carried out to confirm the effectiveness of the proposed method are given.

  • A stabilization method for speed sensorless vector controlled induction motors at Zero Frequency operating condition with multirate adaptive observer
    30th Annual Conference of IEEE Industrial Electronics Society 2004. IECON 2004, 2004
    Co-Authors: N. Yamaguchi, Masaru Hasegawa, S. Doki, S. Okuma
    Abstract:

    This paper proposes a stabilization method for speed sensorless vector controlled induction motors at Zero Frequency operating condition using a new configuration of the adaptive observer. In speed sensorless vector controlled induction motors, it has been pointed out that the speed identification system becomes unstable at Zero Frequency operating condition. This problem is caused by lack of the knowledge of the rotor side of induction motors, and the disturbance such as a parameter mismatch of the stator quantities at Zero Frequency operating condition. In this paper, a new configuration of the adaptive observer, which stabilizes speed sensorless vector control of induction motors without injecting a high Frequency or an excitation signal, is proposed. Firstly, causes of unstable speed identification in the conventional speed sensorless vector control system are considered. Next, a configuration of the adaptive observer based on multirate control in order to stabilize the speed sensorless system at Zero Frequency operating condition is proposed. Finally, validity of the proposed method is shown by experimental results.

Hidehiko Sugimoto - One of the best experts on this subject based on the ideXlab platform.

  • A Speed Sensorless Induction Motor Control Method using Adaptive Flux Observer Improving Stability Around Zero Frequency
    2007 Power Conversion Conference - Nagoya, 2007
    Co-Authors: Toshie Kikuchi, Yasushi Matsumoto, Hidehiko Sugimoto
    Abstract:

    Authors have proposed the speed sensorless vector control method that can stabilize the speed estimator in regeneration region as well as in powering operation. However, actual experimental results showed there were problems when it is driven at unloaded or around Zero Frequency with heavy load. In this paper observer gains are reviewed and modified with considering the phase condition which they must satisfy. Finally, the proposed observer gain scheduling method is confirmed its effectiveness and performance with experiments.

  • Im provingStability Around Zero Frequency
    2007
    Co-Authors: Toshie Kikuchi, Yasushi Matsumoto, Hidehiko Sugimoto
    Abstract:

    Fukui-city, Fukui910-8507, Japan Abstract- Authors haveproposed thespeed sensorless vector control methodthatcanstabilize thespeed estima- torinregeneration region aswellasinpowering opera- tion.However, actual experimental results showedthere wereproblems whenitisdriven atunloaded oraround Zero Frequency withheavyload.Inthis paperobserver gains arereviewed andmodified withconsidering thephase con- dition whichtheymustsatisfy. Finally, theproposed ob- server gain scheduling methodisconfirmed itseffectivenss andperformance withexperiments.