A Hybrid CBPWM Scheme for Single-Phase Three-Level Converters

Wang, Shunliang,Song, Wensheng,Feng, Xiaoyun,Ding, Rongjun The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

A novel hybrid carrier-based pulse width modulation (CBPWM) scheme that combines unipolar and dipolar modulations is proposed for single-phase three-level rectifiers, which are widely applied in railway traction drive systems. The proposed CBPWM method can satisfy the volt-second balancing principle in the complete modulation index region through overmodulation compensation. The modulation scheme features two modulation modes: unipolar and dipolar. The operation range limits of these modulation modes can be modified by changing the separation coefficient. In comparison with the traditional unipolar CBPWM, the proposed hybrid CBPWM scheme can provide advantageous features, such as lower high-order harmonic distortion of the line current and better utilization of switching frequency. The separation coefficient value is optimized to achieve the maximum utilization of these advantages. The experimental results verify the feasibility and effectiveness of the proposed hybrid CBPWM scheme.

Homogeneous preparation of polyamidoamine grafted silica gels and their adsorption properties as Au3+ adsorbents

Rongjun Qu,Xilu Ma,Minghua Wang,Changmei Sun,Xiaomei Sun,Shaoying Sun,Ying Zhang,Ping Yin 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.6

A series of low generation dendrimer polyamidoamine grafted silica gels (named SiO2-G1.0, SiO2-G2.0,SiO2-G3.0) were synthesized via the homogeneous route. The new materials were characterized byscanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermal analysis,pore and surface area analysis, X-ray diffraction analysis (XRD) and elemental analysis. The adsorptionproperties of the three products for Au3+ were studied by batch methods. The adsorbents prepared viathe homogeneous route showed higher adsorption capacities than those via the heterogeneous route. The maximum adsorption capacities for the three could reach up to 1.48, 2.45, and 2.21 mmol g-1,respectively.

Sampled-data Fuzzy Control of Two-wheel Inverted Pendulums Based on Passivity Theory

Rongjun Liu,Junfeng Wu,Dan Wang 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.5

In this paper, an aperiodically sampled-data control scheme is detailed for the two-wheel inverted pendulum using Takagi-Sugeno (T-S) fuzzy models. The passivity theory is applied in the presence of the disturbances in the actuator channel. A two-rule fuzzy model is utilized to represent the two-wheel inverted pendulum. By using the pendulum angle as the antecedent variable of the fuzzy rule, a passive sampled-data controller is established using the pendulum inclination angle and the mean value of the rim motors’ rotary angles. A Lyapunov-like function based on the two fuzzy rules is constructed to develop criteria of passivity, by the utilization of very-strict passivity in terms of the pendulum angle. Then a solution to the gains of sampled-data controller is synthesized to ensure the very-strict passivity of the pendulum system. By the illustrative examples, the effectiveness of the variable-sampling control scheme is validated for the two-wheel inverted pendulum.

A Hybrid CBPWM Scheme for Single-Phase Three-Level Converters

Shunliang Wang,Wensheng Song,Xiaoyun Feng,Rongjun Ding 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

A novel hybrid carrier-based pulse width modulation (CBPWM) scheme that combines unipolar and dipolar modulations is proposed for single-phase three-level rectifiers, which are widely applied in railway traction drive systems. The proposed CBPWM method can satisfy the volt-second balancing principle in the complete modulation index region through overmodulation compensation. The modulation scheme features two modulation modes: unipolar and dipolar. The operation range limits of these modulation modes can be modified by changing the separation coefficient. In comparison with the traditional unipolar CBPWM, the proposed hybrid CBPWM scheme can provide advantageous features, such as lower high-order harmonic distortion of the line current and better utilization of switching frequency. The separation coefficient value is optimized to achieve the maximum utilization of these advantages. The experimental results verify the feasibility and effectiveness of the proposed hybrid CBPWM scheme.

High Precision and Low Force Resonant Probe Based on Quartz Tuning Fork

Qiangxian Huang,Wenqian Wang,Guangpu Wang,Rongjun Cheng,Liansheng Zhang,Hongli Li,Ruijun Li 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.11

To realize the high-precision three-dimensional (3D) measurement of micro-precision devices, a 3D resonant trigger probe based on quartz tuning fork for micro/nano coordinate measuring machine (CMM) is proposed. The probe is composed of a quartz tuning fork, a tapered optical fiber stylus and a microsphere. It vibrates in resonance state and makes contact with the measured surface in the Z direction in tapping mode, while in the X and Y directions, it operates in friction mode. The 3D nano-positioning of the probe is achieved by the changes in resonance parameter caused by the interatomic force between the microsphere and the surface of the measured sample. In this study, the diameter of the probe microsphere can be as low as 80 μm, and the length of the probe stylus is approximately 5 mm. The trigger resolution of the probe in the X, Y and Z directions are 0.44, 0.41 and 0.34 nm, respectively. The probing forces in the X, Y and Z directions are 2.25, 1.81 and 4.24 μN, respectively. Experimental results verify that the proposed probe has the advantages of small size, sub-nano resolution and very low probing force. This probe can be used as the trigger probe of micro/nano CMM, which can be triggered by interatomic force.

WDRP, a DWD protein component of CUL4-based E3 ligases, acts as a receptor of CDPK-related protein kinase 5 to mediate kinase degradation in Arabidopsis

Hui-Juan Teng,Yue Guo,Jian-Qi Wang,Rongjun Li,Ying-Tang Lu,Lei Zhang 한국식물학회 2016 Journal of Plant Biology Vol.59 No.6

CRK5 is a member of the Arabidopsis thaliana Ca2+-dependent protein kinase-related kinase family. Here, a yeast two-hybrid screen was performed with a truncated form of AtCRK5 as bait to identify interacting proteins and determine its physiological roles. One gene encoding the DWD protein WDRP was isolated. Furthermore, in vitro and in vivo co-immunoprecipitation results strongly supported that these two proteins interact with each other. Using a cell-free degradation assay, we also established that CRK5 was an unstable protein that was degraded through the proteasome pathway. The rate of CRK5 degradation was delayed in a WDRP knockout line. On the other hand, the degradation of CRK5 mediated by WDRP might not affect the phosphorylation of PIN2 by CRK5. Overall, we demonstrated that AtCRK5 interacted with a DWD protein, AtWDRP; the protein AtWDRP targets the kinase for ubiquitin-dependent degradation. Therefore, this report describes a new kinase regulation pathway for CRK family proteins in Arabidopsis.

Molecular and phylogenetic analysis of Anaplasma spp. in sheep and goats from six provinces of China

Yan Zhang,Yali Lv,Feifei Zhang,Wenjing Zhang,Jinhong Wang,Yanyan Cui,Rongjun Wang,Fuchun Jian,Longxian Zhang,Changshen Ning 대한수의학회 2016 Journal of Veterinary Science Vol.17 No.4

Members of the genus Anaplasma are important emerging tick-borne pathogens in both humans and animals in tropical and subtropical areas. Here, we investigated the presence of Anaplasma spp. in 621 sheep and 710 goats from six provinces of China. Polymerase chain reaction(PCR) and DNA sequencing were conducted to determine the prevalence of Anaplasma (A.) phagocytophilum, A. ovis and A. bovis targetingthe 16S ribosomal RNA or the major surface protein 4 gene. PCR revealed Anaplasma in 39.0% (240/621) of sheep and 45.5% (323/710)of goats. The most frequently detected species was A. ovis (88/621, 14.2% for sheep; 129/710, 18.2% for goats), followed by A. bovis (60/621,9.7% for sheep; 74/710, 10.4% for goats) and A. phagocytophilum (33/621, 5.3% for sheep; 15/710, 2.1% for goats). Additionally, eight sheepand 20 goats were found to be infected with three pathogens simultaneously. DNA sequencing confirmed the presence of these three Anaplasmaspecies in the investigated areas, and phylogenetic analysis indicated that there was geographic segregation to a certain extent, as well as arelationship between the host and cluster of A. ovis. The results of the present study provide valuable data that helps understand theepidemiology of anaplasmosis in ruminants from China.

Dual-Amplifier Driving in Sequence Method with Switches for Piezoelectric Stack Actuators to Reduce Hysteresis

Liansheng Zhang,Shuang Hao,Pengcheng Zhang,Qiangxian Huang,Rongjun Cheng,Ruijun Li,Ping Wang 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.24 No.12

Piezoelectric actuators have been widely applied to precision positioning platforms. However, the positioning accuracy of piezoelectric ceramic has been significantly affected by its characteristics of hysteresis. Owing to the voltage-keeping feature of capacitive load for piezoelectric ceramic, this paper has proposed a switch-based driving in sequence method, which alternately drives each layer of PZT by using switches. Based on the driving in sequence method, the proposed method is capable of reducing the hysteresis to 1/N of the hysteresis under traditional voltage driving method, while significantly lowering the scale and cost of hardware, compared with the previous driving in sequence method. Thus, it allows for application to hundreds of layers of piezoelectric ceramic. According to experiment results, the hysteresis under different frequencies from 0.1 to 500 Hz for homemade seven-layer piezoelectric ceramic can be reduced from 12.5 to 2.1%. Furtherly, the residual hysteresis can be corrected by applying a simple quadratic-polynomial feedforward control, and the hysteresis is constrained within 0.8%, even with feedforward parameters that are not strictly calibrated. The dual-amplifier driving in sequence method proposed in this paper can significantly reduce the hysteresis in open-loop control of piezoelectric stack actuators, effectively improving the positioning and driving performance and saving cost.