Improving the Accuracy of an Absolute Magnetic Encoder by Using Harmonic Rejection and a Dual-Phase-Locked Loop

Tran, Thuong Ngoc-Cong; Nguyen, Hau Van; Park, Jae Wan; Jeon, Jae Wook

doi:10.1109/tie.2018.2869366

Cited by 34 publications

(8 citation statements)

References 19 publications

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“…When an excitation signal is applied to the resolver, amplitude-modulated sine and cosine signals are output. The phase-locked loop (PLL) [6]- [8] is used to obtain angle information via demodulation. The whole process of obtaining angle information from resolver signals is called resolver-todigital conversion (RDC).…”

Section: Introductionmentioning

confidence: 99%

Quadrature Demodulation Method for Resolver Signal Processing Under Different Sampling Rate

et al. 2022

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Resolvers are widely used as position sensors to obtain angle information. The resolver requires the excitation signal and its amplitude is modulated by the rotor position. The envelope of the modulated signal can be detected precisely only when the samplings are synchronized with the excitation signal. A large error can occur if the synchronization fails. In this paper, the resolver signals are sampled in synchronization with the pulsewidth modulation (PWM) carrier, not the excitation signal. When the resolver excitation signal frequency and the PWM carrier frequency are different, the envelope cannot be detected, so additional signal processing is required to obtain the angle information. For signal processing, multiple auxiliary signals are synthesized based on the sampled signals and quadrature demodulation is performed. A detailed error analysis according to the PWM frequency and motor speed is also performed. The effectiveness is demonstrated through simulation and experimental evidence.INDEX TERMS Phase-locked loop (PLL), resolver-to-digital conversion (RDC), demodulation, resolver, envelope detection.

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Section: Introductionmentioning

confidence: 99%

Quadrature Demodulation Method for Resolver Signal Processing Under Different Sampling Rate

et al. 2022

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“…The resolution is * Chuo university 1-13-27, Kasuga, Bunkyo-ku, Tokyo, Japan, 112-8551 maximized by adjusting the eccentricity of the magnet via fitting. In reference (9,10) , the resolution is improved by increasing the number of magnet poles. However, it is impossible to estimate the absolute angle owing to the multi-polarization of the magnet, and an additional mechanism is required to estimate the absolute angle, which leads to an increase in size.…”

Section: Introductionmentioning

confidence: 99%

Verification of the Usefulness of Eccentric Structure in the Magnetic Encoders Using a Multipole Magnet

et al. 2021

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It is more difficult for magnetic encoders to achieve a higher resolution than optical encoders. The resolution can be improved by multipolarizing the magnet, however the absolute angle cannot be calculated. Using the eccentric rotation of a 4-pole magnet, the authors simultaneously achieved high resolution and absolute angle calculation for a magnetic encoder. In this paper, we propose a high-resolution magnetic absolute encoder using an 8-pole magnet. The higher the eccentricity of the magnet, the easier it is to calculate the offset required to calculate the absolute angle. However, as the eccentricity increases, the angle error increases. The relationship between eccentricity and angle error is clarified, and an appropriate eccentricity is examined.

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“…the power grid under the unbalanced and distorted conditions. So the higher requirements are required for the acquisition of grid voltage synchronization signals [7]- [9]. Therefore, it has theoretical and practical significance to study the phaselocked loop technology under unbalanced and distorted grid conditions [10], [11].…”

Section: Introductionmentioning

confidence: 99%

Design of a High Performance Phase-Locked Loop With DC Offset Rejection Capability Under Adverse Grid Condition

2020

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In the new energy grid-connected power generation system, accurately extracting the grid synchronization signals such as the frequency, phase and amplitude of the grid voltage is the basis for effective control. Aiming at the requirements for detecting grid synchronization signals under unbalanced, harmonics and DC offset voltage mixed conditions, a dual second-order complex coefficient filter with DC offset rejection capability (DSOCCF dc) is proposed, combining the approach of moving average filter (MAF), a novel hybrid filter in dq-frame is designed and on the basis of this design a new synchronous reference frame phase locked loop (SRF-PLL) design approach based on the hybrid filter is proposed. The proposed approach employs moving average filter (MAF) to block the high-frequency harmonics in the grid voltage, and uses DSOCCF dc to separate the fundamental frequency positive and negative sequence and reject DC offset. It can accurately extract the synchronization information of the grid fundamental frequency positive sequence. After simulation and experiment verification, it can be confirmed that the proposed PLL can quickly and accurately lock the properties of the grid voltage under adverse grid condition, and also have high detection accuracy and strong robustness to frequency fluctuations. INDEX TERMS Dual second-order complex coefficient filter (DSOCCF), harmonic, phase-locked loop (PLL), dc offset, moving average filter (MAF).

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Improving the Accuracy of an Absolute Magnetic Encoder by Using Harmonic Rejection and a Dual-Phase-Locked Loop

Cited by 34 publications

References 19 publications

Quadrature Demodulation Method for Resolver Signal Processing Under Different Sampling Rate

Quadrature Demodulation Method for Resolver Signal Processing Under Different Sampling Rate

Verification of the Usefulness of Eccentric Structure in the Magnetic Encoders Using a Multipole Magnet

Design of a High Performance Phase-Locked Loop With DC Offset Rejection Capability Under Adverse Grid Condition

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