http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Dongxing Zhang (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
Active noise cancellation frequency‑locked loop with a notch filter
Lei Pan,Dongxing Xu,Jingmei Zhang,Chang Yin,Zifeng Wu,Yingjun Guo 전력전자학회 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.12
To improve the performance of frequency-locked loops (FLLs) under distorted grid conditions, a series of pre-filtering techniques have been added to remove harmonics. One of them is the FLL-based comb filter (COMB-FLL), which offers a high disturbance rejection capability. However, it has some disadvantages, such as approximating a fractional delay and compensating an accumulated round-off error in the digital implementation of COMB-FLL. To alleviate these problems, this study proposes an active noise cancellation (ANC) FLL with a notch filter (NF), which incorporates an NF and an ANC to improve the frequency-locking ability. In this research, the structure of a comb filter is simplified into an NF, and an ANC is creatively introduced to eliminate harmonics from the frequency signal obtained by FLL. Furthermore, ANC has been improved to make it suitable for electricity-related applications. The proposed FLL features a unique cascade structure, which has excellent frequency-locking ability and dynamic characteristics under normal, abnormal, and harmonically distorted grid conditions. The simulations and experimental results verify the validity and reliability of the proposed FLL.
-
Pang, Yi,Zhang, Jingmei,Xu, Dongxing,Yin, Chang,Wu, Zifeng,Sun, Hexu,Pan, Lei The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.1
This paper proposes a model predictive control (MPC) algorithm designed for nine-switch converter with output filter (NSCOF) to control two three-phase AC loads independently. A state function of each leg of nine-switch converter (NSC) is established to characterize the internal conditions of the NSC because the traditional model of the NSCOF does not involve the interior model of the NSC. Based on the NSCOF model with the state function of each leg, a prediction model of NSCOF is constructed. The two AC terminals of NSCOF are treated as one module when the MPC is designed. The proposed MPC achieves controlling two three-phase AC loads working under different frequency modes. Furthermore, this algorithm is independent of the modulation method for reducing the difficulty of the controller design and its limits. The simulation and experimental results reveal that the steady-state and dynamic response performance of NSCOF are substantially improved using MPC.
-
Xiangxu Qu,Dongxing Cao,Mengying Song,Yuting Zhang 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.10
This paper proposed a cable-driven robot for performing lower limb rehabilitation therapies. Based on important requirements intended to confirm positive tensions within a redundant number of cables, a simple way of examining the operational area for cable-driven structures is discussed and implemented for a rehabilitation device. In contrast, a more suitable scheme is to add torsion springs at the robot joints. These springs can create resistance torque, potentially reducing the number of cables and solving issues of interference. An examination approach using the virtual joint method is suggested to describe the stiffness of the robot amidst rehabilitation development when considering mass, external force, and compliant impacts of the structural joints. Simulated and experimental results demonstrated that the proposed method was effective and the designed robot can fulfil lower limb rehabilitation with advantages such as being lightweight, low-cost, and having simple transmission.
-
Gaoshen Cai,Lihui Lang,Kangning Liu,Sergei Alexandrov,Dongxing Zhang,Xiying Yang,Chan Guo 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.2
Confirmation of material properties is an important research area for determining metals deformation behavior. In order to research the effect of flow stress calculation on aluminum alloy sheet deformation behavior,warm sheet bulging test was carried out to obtain bulging height - pressure curves with different bulging heightsand diameters in this study. Based on the bulging parts profile data measured by three coordinate measuringmachine, the least square circle fitting radius were fitted. Existing theoretical models for radius of curvatureand thickness were compared and best models were selected to obtain more accurate stress - strain curves bycalculating the bulging flow stress. Combination model was used to calculate the bulging height - pressurecurves obtained by bulging test and the stress-strain curves with different temperatures and pressure rates wereobtained. A monotonous increasing function was resulted which is of great significance in the area of formabilityand deformation behavior of warm sheet hydroforming.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
