Short-term Power Load Forecasting Based on Phase Space Reconstruction and EMD-ELM

Zou Hongbo,Yang Qinhe,Chen Junting,Chai Yanhui 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.5

With the increasing complexity of the world energy structure, the uncertainty of the power system increases significantly, and the accuracy of the short-term power load forecasting is of great significance to the safe, economical and reliable operation of the power system. In order to further improve the accuracy of short-term power load forecasting, this paper innovatively combines the theories such as phase space reconstruction, empirical mode decomposition, and extreme learning machine to establish a new short-term power load forecasting model based on phase space reconstruction and EMD-ELM. The prediction results show that the root means square error, average relative error and global maximum relative error of the short-term power load forecasting model based on phase space reconstruction and EMD-ELM are much smaller than other forecasting models, which verifies the correctness and effectiveness of the short-term load forecasting method.

Effect of Sodium Tripolyphosphate on Clay Tolerance of Polycarboxylate Superplasticizer

Hongbo Tan,Yulin Guo,Baoguo Ma,Jian Huang,Benqing Gu,Fubing Zou 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.8

High fluidity concrete has been widely used in modern civil engineering project to ensure that the highly efficient construction process canbe achieved. Generally, the fluidity can be obtained with the incorporation of superplasticizer system composed of polymers and retarders. Sodium tripolyphosphate (STPP), a commonly used retarder in cement-based material, can obviously increase the dispersion ofpolycarboxylate superplasticizer (PCE), and this has been widely employed in real concrete. However, the effect of STPP on clay toleranceof PCE has not been confirmed until now, and it is still uncertain whether STPP in PCE system has positive or negative effect on workabilityof fresh concrete with poor-quality aggregates containing montmorillonite (Mt) which is one of the most harmful clay minerals. In this study,the effect of STPP on fluidity of cement-Mt paste with PCE has been investigated. The fluidity was tested with mini slump to assess the claytolerance of PCE. The adsorption amount of PCE and STPP in Mt suspension was tested with total organic carbon analyzer and inductivecoupled plasma emission spectrometer to characterize the adsorption behavior. The interlayer spacing was evaluated with X-rayDiffractometer and the structure of intercalated Mt by PCE was characterized with Fourier-transform infrared spectrometer and thermogravimetric analyzer, and these results were used to illustrate the effect of STPP on intercalation of PCE. Finally, the dispersion model wasproposed to reveal the mechanism behind. The results show that STPP can disperse the Mt particles and increase adsorption amount of PCEin Mt suspension, thereby accelerating rather than hindering the intercalation of PCE into Mt. The fluidity of cement-Mt paste with PCESTPPsystem is depended on the added dosage of STPP: with the dosage less than 0.20%, the contribution of STPP to dispersing the cementparticles predominates, hence increasing the fluidity of the paste and improving the clay tolerance; while with the dosage more than 0.20%,the acceleration of the intercalation of PCE resulting from STPP becomes predominant, thereby reducing the fluidity of the paste. This resultcan provide useful experience for the improvement in clay tolerance of PCE in real concrete with poor aggregate containing Mt.

INTEGRATED STEADY-STATE AND DYNAMIC SIMULATION OF MULTI-UNIT AIR CONDITIONERS BASED ON TWO-PHASE FLUID NETWORK MODEL

HONGBO XU,SHUANGQUAN SHAO,Huiming Zou,Changqing Tian 대한설비공학회 2012 International Journal Of Air-Conditioning and Refr Vol.20 No.4

An integrated simulation model is developed to investigate the steady-state and dynamic performance of multi-unit air conditioners (MUACs). It is built as two-phase fluid network which is able to describe different systems by incidence matrixes. And the submodels are embedded in the system framework, where the submodels can be either steady-state or dynamic model, distributed parameter or lumped parameter model. For this case, the numerical submodels are employed with moving-boundary models of condenser and evaporator, steady-state models of compressor and electronic expansion valve. The comparison with experimental data shows that it cannot only predict the steady-state performance, but also catch dynamic trends with high accuracy, for example, the differences of evaporating pressure < ${\pm}4%$, condensing pressure < ${\pm}3%$, compressor discharge temperature < ${\pm}4^{\circ}C$, superheating degree < ${\pm}2^{\circ}C$ and subcooling degree < ${\pm}1^{\circ}C$. Therefore, the simulation model is confirmed as an effective tool to analyze the steady and transient characteristics and optimize the design and control algorithm of MUACs.

Outd7b facilitates T cell activation and inflammatory responses by regulating Zap70 ubiquitination

( Hongbo Hu ),( Hui Wang ),( Yichuan Xiao ),( Jin Jin ),( Jae Hoon Chang ),( Qiang Zou ),( Xiaopin Xie ),( Xuhong Cheng ),( Shao Cong Sun ) 영남대학교 약품개발연구소 2016 영남대학교 약품개발연구소 연구업적집 Vol.26 No.-

Signal transduction from the T ceII receptor (TCR) is crucial for T cell-mediated immune responses and, when deregulated, also contributes to the development of autoimmunity. How TCR signaling is regulated is incompletely understood. In this study, we demonstrate a ubiquitin-dependent mechanism in which the deubiquitinase Otud7b has a crucial role in facilitatinq TCR sig­naling. Upon TCR ligation, Olud7b is rapidly recruited to the tyrosine kinase Zap70, a central mediator of TCR-proximal sig­naling. Otud7b deficiency attenuates the activation of Zap70 and its downstream pathways and impairs T cell activation and differentiation, rendering mice refractory to T cell-mediated autoimmune and inflammatory responses. Olud7b facilitated Zap70 activation by deubiquitinating Zap70, thus preventing the association of Zap70 with the negative-regulatory phospha­tases SIs1 and Sts2. These findings establish Otud7b as a positive requlator of TCR-proximal signaling and T cell activation. highlighting the importance of deubiquitination in regulaling Zap70 function.

Influence of Driving Voltage on Starting Performance of High-Speed Permanent Magnet Synchronous Starter–Generator for Micro-gas Turbine

Qiu Hongbo,Wang Kun,Zou Xutian,Xiong Bin,Wu Xuanzong 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.6

The high-speed electrical machine as a critical power conversion unit in the micro gas turbine generation system needs to integrate the functions of starter and generator, which makes the control system of the machine more complex. In order to simplify the control system and improve the starting speed of the generation system with the help of the intrinsic starting ability of the machine, a high-speed starter–generator with multilayer composite solid rotor is proposed. The machine with the proposed solid rotor can realize self-start when it works in starting mode. Taking a 40 kW 20,000r/min high-speed permanent magnet machine as an example, the fi nite element model of the machine is established. The infl uence of driving voltage on the machine starting performance is analyzed and the start-up time, locked rotor parameters of the machine under diff erent driving voltages are further studied. Furthermore, in order to reveal the infl uence mechanism of driving voltage on the machine starting performance, the starting torque is decoupled and the infl uence of driving voltage on the decoupled torques is studied. Finally, the machine prototype is tested, and the correctness of the fi nite element model is verifi ed by comparing the experimental data with the fi nite element calculation data.

Effect of sodium gluconate on dispersion of polycarboxylate superplasticizer with different grafting density in side chain

Fubing Zou,Hongbo Tan,Yulin Guo,Baoguo Ma,Xingyang He,Yang Zhou 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.55 No.-

Sodium gluconate is a commonly used retarder, and the incorporation of SG has been accepted as the most efficient way to improve the basic performance of polycarboxylate superplasticizer (PCE) system in real concrete. However, this improvement cannot be always achieved, and the main reason for this uncertainty is because the interaction between PCE and SG has not completely understood. In order to gain deeper insight into this interaction, adsorption behavior and dispersion mechanism of PCE-SG system involved in two kinds of PCE with different grafting density of carboxyl groups in side chain have been investigated. Specifically, the dispersion was assessed with the fluidity of the cement paste, and adsorption behavior was estimated with total organic carbon and zeta potential. The combination between PCE and SG was characterized with conductivity, dynamic light scattering, and X-ray photoelectron spectroscopy. Finally, several models were proposed to illustrate the mechanism behind. The results show that gluconate grafted as side chain of PCE and the increase in length of PEO chain caused by addition of SG can provide contribution to dispersion. Competitive adsorption between SG and PCE would take place to reduce the dispersion, and the declining degree depends on the relative adsorption between PCE and SG. Dispersion of PCE-SG is not only dependent on added dosage of SG, but also decided by molecular structure of PCE. This result provides guidance on how to promote the basic performance of the PCE-retarder system in real engineering practice.

Performance characteristics around the TDC of linear compressor based on whole-process simulation

Huiming Zou,Mingsheng Tang,HONGBO XU,SHUANGQUAN SHAO,Changqing Tian 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.10

A whole-process simulation platform is established for linear compressor to analyze the performance characteristics on different pistondisplacement conditions from small oscillation without pumping till to rushing out of the top dead center (TDC). The measuring methodsof the related parameters in the model are presented and the values of these parameters are obtained from an actual test. The simulatedresults agreed well with the experimental results under the same working conditions. The errors of the effective voltage, the effectivecurrent, the compression efficiency and the phase angle between the current and the displacement were within ±6.9%,±8.5%,±6.2%and±13.4%, respectively. Based on this simulation platform, the performance characteristic around the TDC of the linear compressor ondifferent working conditions is analyzed. The performance comparison on 60 Hz shows that the compression efficiency near to the TDCon 0.7 MPa is higher than that on 0.5 MPa because the phase angle α under that condition is around 90°, but the operation reliability on0.7 MPa is worse than that on 0.5 MPa because the jump phenomenon happens when the piston displacement goes near to the TDC. Thejump phenomenon results in unstable operation as the piston displacement jumps from the position before the TDC to the position afterthe TDC. According to the simulation on different power frequency, two important performance characteristics are inferred. One is thatthere is an inflection point in the curve of the phase angle α versus the displacement at the TDC. This characteristic is a good choice forthe TDC detection. The other is that the jump phenomenon is prone to happening when there exist different displacement responses onthe same voltage value, becoming inconspicuous when the power frequency is decreased and disappearing when the power frequency isincreased. Based on this characteristic, the jump phenomenon can be avoided through suitable system configuration and frequency adjustment.

Design of the Linear Quadratic Structure Based Predictive Functional Control for Industrial Processes Against Partial Actuator Failures Using GA Optimization

Xiaomin Hu,Hongbo Zou,Limin Wang 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.3

This paper addresses the genetic algorithm (GA) optimization and the linear quadratic (LQ) structurebased predictive functional control (PFC) for batch processes under non-repetitive unknown disturbances and partialactuator faults. First, by adopting the extended non-minimal state space (ENMSS) model in which the state variablesand the tracking error are united, the new state vector with more degrees is provided for the controller design. Inorder to enhance the ensemble control performance under the PFC structure, GA is adopted for the optimizationof the weighting matrix in the controller. The case study on the injection velocity control in an injection moldingmachine demonstrates the effectiveness of the proposed PFC scheme against various disadvantages.