4-kW 3-phase rectifier with high efficiency and wide operational range via 3-mode SVPWM

Lin, Jiaqing,Li, Zhizhong,Zhang, Bo,Zhang, Guidong,Qiu, Wei The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.6

There are 6 modes in the full working state of a traditional 3-phase rectifier, and each mode is necessary for power factor correcting and for realizing the corresponding DC-link voltage. It is obvious that too many modes in the full working state increase the switch stresses, which results in high switching loss and increased economic cost. Reducing the number of working modes is a feasible solution to solve this problem. By improving the m-mode controllability in inverters, a 3-mode control strategy is derived for the traditional 3-phase rectifier to enhance its operational features. Note that the proposed control strategy can maintain a high-power factor above 0.99 and have higher efficiency when compared with the traditional control strategy. Finally, a lab-prototype with a load varying from 800 W to 4 kW is conducted to validate the feasibility of the proposed control strategy. Experimental results show that all of the tested cases have a 0.99 power factor and that highest efficiency of 96.7%. The results also reveal that the proposed strategy is superior to the traditional one in laboratory conditions. In addition, the proposed method is generalized and can be extended to other rectifier topologies.

Research on “Wind‑Net‑Vehicle Load” Optimization Scheduling Considering Load Margin Domain

Jiaqing Zhong,Yiming Wang,Xiaohui Zhang 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.3

Under the current situation of widespread application of electric vehicles (EV), how to optimize the two uncertain loads of electric vehicle charging and battery charging in the Battery Charge-Swap Station (BCSS) has become an urgent problem. In view of the above problem, this paper defnes the load margin domain index, detects the daily load change, and performs peak shaving and valley flling on the load with large fuctuation range to make it smooth and stable. On this basis, with the obtained load margin domain as a constraint, combined with time-of-use electricity prices and considering wind farm gridconnected access, an “wind-net-vehicle load” optimized dispatching model was established to maximize system economic benefts, and at the same time play an important role in reducing the rate of wind abandonment. Finally, this paper studies the fusion of credibility theory and fuzzy chance constraints programming, introduces the credibility measure index, and makes the explicit equivalent treatment of the fuzzy chance constraint condition. The particle swarm optimization algorithm with a constriction factor is used to optimize the scheduling model. The rationality of the model and its strategy is verifed by examples.

A Multi-objective Planning of Transmission Line Balance Degree Based on Power Flow Entropy Theory

Jiaqing Zhong,Fanfan Gao,Xiaohui Zhang 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.5

The equilibrium degree of transmission lines in the multi-objective planning of power grid is studied in this paper. The main purpose of the study is to ensure the economy and improve the balanced distribution of active power fl ow of transmission lines, furthermore increase the adaptability of transmission lines in the future power grid. The problem is mainly focus on the single-level of line load rate, in researching on the distribution balance of active power fl ow in transmission lines. Three indexed, which are line load rate power fl ow entropy, active loss rate power fl ow entropy and transmission effi ciency power fl ow entropy, are defi ned in this paper. The weighted sum of the three indexes is defi ned as the balance factor of active power fl ow distribution in transmission lines. This factor is used in transmission network planning to improve the overall balance of active power fl ow distribution in transmission lines. On this basis, a multi-objective programming model with minimum economic cost and maximum equilibrium factor of transmission network is established. The model is solved by using multiobjective bacterial colony chemotactic algorithm (BCC) and optimal compromise solution method. The results verify the superiority and rationality of the proposed method and model.

Trust-based Access Control Model in Multi-domain Environment

Zhang Qikun,Wang Ruifang,Qu Jiaqing,Gan yong,Zheng Jun 보안공학연구지원센터 2014 International Journal of Security and Its Applicat Vol.8 No.5

Cuprum Metal-Organic-Framework and Polyacrylonitrile-Derived Cu-N-C Electrocatalyst for Application in Zinc-Air Batteries

Yajun Zhao,Jintao Chen,Xiaorui Li,Jiaqing Zhang,Yanan Li,Yajun Zhao,Liye Cao,Xiaoshi Jin 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2020 NANO Vol.15 No.02

Cu-N-C electrocatalyst was successfully prepared with Cu-BTC and polyacrylonitrile as templates by electrospinning and in-situ growth method. The effect of various N-doped content on the electrochemical performance of the catalyst were investigated and the Cu-N-C-0.25 exhibited the best OER/ORRcatalytic activities. When it was applied to the cathode of the zinc-air batteries, the power density of Cu-N-C-0.25 was 209.1 mW cm -2, which exceeded that of the commercial Pt/C + IrO2 hybrid catalyst (157 mW cm -2). The excellent electrochemical performance may be attributed to large number of active sites and high specific surface area on Cu-N-C electrocatalyst. It will be a promising alternative to precious metal catalysts containing Pt, Ir or Ru and their oxides.

Pituitary P62 deficiency leads to female infertility by impairing luteinizing hormone production

Li Xing,Zhou Ling,Peng Guiliang,Liao Mingyu,Zhang Linlin,Hu Hua,Long Ling,Tang Xuefeng,Qu Hua,Shao Jiaqing,Zheng Hongting,Long Min 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

P62 is a protein adaptor for various metabolic processes. Mice that lack p62 develop adult-onset obesity. However, investigations on p62 in reproductive dysfunction are rare. In the present study, we explored the effect of p62 on the reproductive system. P62 deficiency-induced reproductive dysfunction occurred at a young age (8 week old). Young systemic p62 knockout (p62 -/- ) and pituitary-specific p62 knockout (p62 flox/flox αGSU cre ) mice both presented a normal metabolic state, whereas they displayed infertility phenotypes (attenuated breeding success rates, impaired folliculogenesis and ovulation, etc.) with decreased luteinizing hormone (LH) expression and production. Consistently, in an infertility model of polycystic ovary syndrome (PCOS), pituitary p62 mRNA was positively correlated with LH levels. Mechanistically, p62 -/- pituitary RNA sequencing showed a significant downregulation of the mitochondrial oxidative phosphorylation (OXPHOS) pathway. In vitro experiments using the pituitary gonadotroph cell line LβT2 and siRNA/shRNA/plasmid confirmed that p62 modulated LH synthesis and secretion via mitochondrial OXPHOS function, especially Ndufa2, a component molecule of mitochondrial complex I, as verified by Seahorse and rescue tests. After screening OXPHOS markers, Ndufa2 was found to positively regulate LH production in LβT2 cells. Furthermore, the gonadotropin-releasing hormone (GnRH)-stimulating test in p62 flox/flox αGSU cre mice and LβT2 cells illustrated that p62 is a modulator of the GnRH-LH axis, which is dependent on intracellular calcium and ATP. These findings demonstrated that p62 deficiency in the pituitary impaired LH production via mitochondrial OXPHOS signaling and led to female infertility, thus providing the GnRH-p62-OXPHOS(Ndufa2)-Ca 2+ /ATP-LH pathway in gonadotropic cells as a new theoretical basis for investigating female reproductive dysfunction.

Protein profiling predicts the response to anthracycline and taxanes based neo-adjuvant chemotherapy in breast cancer

Shu Wang,Houpu Yang,Jiajia Guo,Miao Liu,Fuzhong Tong,Yingming Cao,Bo Zhou,Peng Liu,Lin Cheng,Fei Xie,Deqi Yang,Jiaqing Zhang 한국바이오칩학회 2011 BioChip Journal Vol.5 No.1

Neo-adjuvant chemotherapy for breast cancer substantially benefits patients who achieve pathological response. However, clinical or pathological response information can only be obtained a period of time after chemotherapy. The identification of novel bio-markers or the application of new technique that can be used to predict treatment response before che-motherapy would allow therapy to be tailored on an individual patient basis. The purpose of this study is to identify the chemo-sensitivity and chemo-resistance related proteins using antibody microarray profiling, and to develop a multi-protein predictive model for breast cancer. Total protein was extracted from core needle biopsy samples obtained from 15 patients before treatment with neo-adjuvant TA(combination of taxanes and anthracycline) chemotherapy. Protein profiling was analyzed by antibody microarray. 10 pati-ents were used as training set to develop the predictive model using the software PAM(prediction analysis of microarray). Another 5 patients were used as a validation set to test the model. In cross-validation, the mole-cular predictive model showed an accuracy of 90%, in independent validation, the model classified the cases with an accuracy of 80%. In conclusion, the proteomic predictive model has the potential to predict pathological response to neo-adjuvant TA chemotherapy.