Frequency-domain Analysis of A Modified Active Disturbance Rejection Control With Application to Superheated Steam Temperature Control

Zhenlong Wu,Fan Zhang,Gengjin Shi,Ting He,Donghai Li,YangQuan Chen 제어로봇시스템학회 2019 제어로봇시스템학회 국제학술대회 논문집 Vol.2019 No.10

Superheated steam temperature (SST) systems face many control difficulties caused by unknown disturbances and high order dynamics. This is becoming more and more severe due to the rapid growing of intermittent renewable generation. To improve the tracking and disturbance rejection performance of SST systems, a modified active disturbance rejection control (ADRC) is proposed. Based on its equivalent structure, this paper develops the frequency-domain analysis of the modified ADRC to present the influence of parameters on the control performance. Then the modified ADRC based on the frequency-domain analysis is applied to the SST control to verify the superiority of the modified ADRC. Based on the results of the simulation and the field application on a power plant simulator, the modified ADRC can obtain the best tracking performance with a small overshoot and short settling time compared with other comparative controllers. Besides, the modified ADRC has the smallest fluctuation range of SST under the input disturbance and load varying conditions. The superiority of the modified ADRC ensures the satisfactory control performance and shows a great potential in industrial applications.

Active Disturbance Rejection Control for Fluidized Bed Combustor

Zhenlong Wu,Donghai Li,Yali Xue,Lingmei Wang,Jing Wang 제어로봇시스템학회 2016 제어로봇시스템학회 국제학술대회 논문집 Vol.2016 No.10

Active disturbance rejection control (ADRC) is applied in fluidized bed combustor (FBC) facing some control difficulty. By analyzing the difficulties, ADRC controllers are designed for the power loop and the bed temperature loop of FBC system. The simulation demonstrates both loops with ADRC have a better tracking speed and a stronger robustness, the power loop can inhibit the input and output disturbance quickly and the temperature loop has a slight advantage in disturbance rejection. Besides, manipulated variables is analyzed by the phase diagrams.

The Disturbance Rejection Design Based on Physical Feedforward for Solid Oxide Fuel Cell

Zhenlong Wu,Wangying Shi,Donghai Li,Ting He,Yali Xue,Minfang Han,Song Zheng 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10

The output voltage control of the Solid Oxide Fuel Cell (SOFC) is challenging due to the strong nonlinearity, modelling uncertainty, the dramatic change of the external current load and constraints on the amplitudes and change rates of the actuator. Besides, the desired range of the fuel utilization is another difficult for the control strategy. In this paper, Active disturbance rejection control (ADRC) is proposed to handle the nonlinearity, uncertainty and the external disturbance, and physical feedforward is designed to speed up the response of the whole system and keep the fuel utilization in the desired range. Instead of the SOFC model, the design of physical feedforward is based on the definition of fuel utilization which is featured by simplicity, generality and effectiveness. Simulation results show that the proposed control strategy has smaller variation range of the fuel utilization, shorter time of the changing process of the output voltage and better robustness than others control strategies.

Dynamic characteristics of the cavitation clouds of submerged Helmholtz self-sustained oscillation jets from high-speed photography

Qiang Wu,Wei Wei,Bo Deng,Pan Jiang,Deng Li,Mengda Zhang,Zhenlong Fang 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.2

Experiments were conducted to investigate the cavitation behavior of Helmholtz self-sustained oscillation jets. In this paper, highspeed photographic technology was used to capture the flow details of cavitation with various nozzle structures and operating pressures from 1.0 MPa to 3.0 MPa. Furthermore, an in-house code based on a matrix approach that processes gray values with various statistical methods was used to quantitatively evaluate the cavitation jet of waters generated by Helmholtz nozzles. The mean values of the normalized gray levels of the images were used as a metric to measure the lengths of the cavitation clouds. When the original data were smoothed by a 15th lowess filter to exclude the noise of the images, the periods of cavitation cloud shedding were obtained accordingly, and the average period had a magnitude of 10 -4 . All of the smoothed results of the original data captured a two-peak shape that comprises a large peak and a mild hump. Image processing results showed that the Helmholtz nozzle produced greater cavitation intensity than a traditional conical nozzle. The shear-layer instability waves disappeared within 10d 1 downstream from the injector exit. The cavitation clouds propagated a distance of approximately 1–10d 1 at various pressure ratios, and the clouds were continuous within this distance. The geometry of the nozzle strongly affected the length and shedding period of the cavitation cloud. As described in the discussion section of this paper, when the cavity length was doubled, the length of the cavitation cloud decreased approximately 26.5 %; however, the period of the cavitation cloud shedding increased approximately 10 %. The longest cavitation cloud appeared when the ratio of the cavity diameter and the upper nozzle diameter was eight. Excessively small or large diameters were not conducive to the development of cavitation, whereas the effect of the pressure ratio on the cavitation cloud length was positive. When other conditions remained unchanged, the lump shedding period decreased as the pressure ratio was increased to 25. When the pressure ratio exceeded 25, the cavitation cloud shedding period remained constant.

Research on the Cascade Active Disturbance Rejection Control of Superheated Steam Temperature Based on Gain Scheduling

Gengjin Shi,Ting He,Zhenlong Wu,Donghai Li 제어로봇시스템학회 2019 제어로봇시스템학회 국제학술대회 논문집 Vol.2019 No.10

The boiler superheated steam temperature (SST) is a typical thermal process with great inertia and large delay. Its dynamic characteristics tend to change significantly with the variation of the operating point so that constant-parameter control system are not able to provide satisfactory dynamic control performance. Cascade active disturbance rejection control systems are commonly used in the control of the process with high order, especially in the control of superheated steam temperature. However, with the variations of loads, the tuning of linear ADRC (LADRC) becomes more complex. In order to simplify the tuning of bandwidth-parameters of LADRC in different loads, this paper studies control effects of cascade ADRC system of SST applied gain scheduling. Simulation results demonstrate that scheduling the bandwidth of feedback control system best improves dynamic characteristics of SST control system. Compared with the optimization of bandwidth-parameters using fruit fly algorithm, gain scheduling has better control performance in the control of SST.

A Quinoline-thiooxorhodamine Conjugate for Fluorescent Hg²⁺ Recognition in Aqueous Media and Living Cells

Tang, Lijun,Wen, Xin,Dai, Xin,Wu, Di,Huang, Zhenlong Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.11

A quinoline-thiooxorhodamine conjugate fluorescent sensor (1) has been synthesized. Sensor 1 exhibits high selectivity and sensitivity to $Hg^{2+}$ in $H_2O$/DMSO (95/5, v/v, HEPES 20 mM, pH = 7.4) solution with fluorescence detection. Other tested metal ions do not induce any significant fluorescence intensity changes. Sensor 1 interacts with $Hg^{2+}$ through a 1:1 binding stoichiometry with a good anti-inference ability. In addition, fluorescent imaging of $Hg^{2+}$ in Hela cells is also successfully demonstrated.

Active Disturbance Rejection Control for Boiler Superheated Steam Temperature

Makeximu,Min Zhu,Yong Sun,Zhenlong Wu,Donghai Li,Yali Xue 제어로봇시스템학회 2016 제어로봇시스템학회 국제학술대회 논문집 Vol.2016 No.10

In this paper, an active disturbance rejection control (ADRC) with tracking differentiator (TD) solution is proposed and tested on a certain four operating condition model. The proposed system with a cascaded control scheme is constructed based on a linear Active disturbance rejection controller (LADRC) with parameters optimized under a modified fruit fly algorithm. The tracking performance could be improved by the tracking differentiator with flexible damping. The simulation results indicate that the proposed strategy could effectively balance rapid and stable responses.

Study on Power Control Methodology of the Accelerator Driven Sub-critical Reactor System

YuXin Yang,Zhiwei Zhou,Ting He,Zhenlong Wu,Donghai Li 제어로봇시스템학회 2017 제어로봇시스템학회 국제학술대회 논문집 Vol.2017 No.10

The Accelerator Driven sub-critical reactor System (ADS) is an innovative system for the utilization of nuclear energy, for which the strategy of power control is different from the current critical reactor. In this paper, the physical model of the sub-critical reactor core of ADS was built according to the point space-time neutron kinetics equations with delayed neutrons produced by precursor nuclides of one equivalent group. The linear approximation of equations was done near the steady working point, based on which, the kinetic neutronics and thermal characteristics of ADS were analyzed, and the strategy of power control system of the sub-critical reactor core of ADS was studied. A constant power control system was designed by means of the Proportion-Integral Derivative (PID) controller and the Linear Active Disturbance Rejection Controller (LADRC). The controllers were tuned in the linearized model and then tested in the actual nonlinear model by means of Matlab/Simulink. The results show, that for both methods, the control system can avoid the disturbances induced by the external neutron source intensity or the reactivity, and make the power constant with little over shoot and short settling time, and the control effect of LADRC is better than PID.

Genistein activates endothelial nitric oxide synthase in broiler pulmonary arterial endothelial cells by an Akt-dependent mechanism

Ying Yang,Wei Nie,Jianmin Yuan,Bingkun Zhang,Zhong Wang,Zhenlong Wu,Yuming Guo 생화학분자생물학회 2010 Experimental and molecular medicine Vol.42 No.11

Deregulation of endothelial nitric oxide synthase (eNOS)plays an important role in the development of multiple cardiovascular diseases. Our recent study demonstrated that genistein supplementation attenuates pulmonary arterial hypertension in broilers by restoration of endothelial function. In this study, we investigated the molecular mechanism by using broiler pulmonary arterial endothelial cells (PAECs). Our results showed that genistein stimulated a rapid phosphorylation of eNOS at Ser1179 which was associated with activation of eNOS/NO axis. Further study indicated that the activation of eNOS was not mediated through estrogen receptors or tyrosine kinase inhibition, but via a phosphatidylinositol 3-kinase (PI3K)/Akt-dependent signaling pathway, as the eNOS activity and related NO release were largely abolished by pharmacological inhibitors of PI3K or Akt. Thus, our findings revealed a critical function of Akt in mediating genistein-stimulated eNOS activity in PAECs, partially accounting for the beneficial effects of genistein on the development of cardiovascular diseases observed in animal models.

Genistein activates endothelial nitric oxide synthase in broiler pulmonary arterial endothelial cells by an Akt-dependent mechanism

Yang, Ying,Nie, Wei,Yuan, Jianmin,Zhang, Bingkun,Wang, Zhong,Wu, Zhenlong,Guo, Yuming Korean Society for Biochemistry and Molecular Bion 2010 Experimental and molecular medicine Vol.42 No.11

Deregulation of endothelial nitric oxide synthase (eNOS) plays an important role in the development of multiple cardiovascular diseases. Our recent study demonstrated that genistein supplementation attenuates pulmonary arterial hypertension in broilers by restoration of endothelial function. In this study, we investigated the molecular mechanism by using broiler pulmonary arterial endothelial cells (PAECs). Our results showed that genistein stimulated a rapid phosphorylation of eNOS at $Ser^{1179}$ which was associated with activation of eNOS/NO axis. Further study indicated that the activation of eNOS was not mediated through estrogen receptors or tyrosine kinase inhibition, but via a phosphatidylinositol 3-kinase (PI3K)/Akt-dependent signaling pathway, as the eNOS activity and related NO release were largely abolished by pharmacological inhibitors of PI3K or Akt. Thus, our findings revealed a critical function of Akt in mediating genistein-stimulated eNOS activity in PAECs, partially accounting for the beneficial effects of genistein on the development of cardiovascular diseases observed in animal models.