scholarly journals Research on Control Method of Wet Desulfurization System for Coal-fired Boiler

2021 ◽  
Vol 2076 (1) ◽  
pp. 012063
Author(s):  
Xingchao Zhang ◽  
Jianhong Liu ◽  
Peng Hu
Keyword(s):  
Flue Gas ◽  
Control Method ◽  
Ph Value ◽  
Dynamic Performance ◽  
Control Process ◽  
Internal Model Control ◽  
Flue Gas Desulfurization ◽  
System Control ◽  
Model Control ◽  
Key Factor

Abstract In wet flue gas desulfurization technology, the key factor affecting flue gas SO2 absorption is the control of slurry pH value in the absorption tower. However, most of the commonly used pH value control methods have some defects and cannot fully meet the system control requirements. On the basis of the analysis for the problems in the control process, this paper discussed a control strategy based on internal model control algorithm. The system simulation test showed that this control method had good dynamic performance, robustness and anti-interference, which could realize the relatively accurate control of pH value for wet flue gas desulfurization system, and achieve the control goal.

scholarly journals Internal Model Control for Rank-Deficient System with Time Delays Based on Damped Pseudo-Inverse

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 264
Author(s):  
Meiying Jiang ◽  
Beiyan Jiang ◽  
Qi Wang
Keyword(s):  
Time Delay ◽  
Internal Model ◽  
Control Method ◽  
Dynamic Performance ◽  
Delay System ◽  
Internal Model Control ◽  
Damping Factor ◽  
Model Control ◽  
Value Decomposition ◽  
Pseudo Inverse

It is a challenge to design a satisfactory controller for a complex multivariable industrial system with minimal offsetting and a slow response. An internal model control method is proposed for rank-deficient systems with a time delay based on a damped pseudo-inverse. An internal model control was designed to obtain the desired dynamic characteristics of the system by transforming the time-delay system into a system without a time delay, following the Pade approximation approach. By introducing a damping factor, the internal model controller was designed based on a damped pseudo-inverse, since the inverse matrix of the rank-deficient system does not exist. Furthermore, a singular value decomposition was used to analyze the steady-state performance of the system. The selection of the damping factor was also presented, and a μ analysis was made to evaluate the stability of the system. To demonstrate the effectiveness of the proposed method, a crude distillation process with five inputs and four outputs was considered as an example. The simulation results illustrate that not only can the proposed strategy guarantee the system’s stability, but it also has a relatively good dynamic performance.

Research on the Internal Model Decoupling Control of High Speed Spindle

2012 ◽  
Vol 605-607 ◽  
pp. 1496-1501
Author(s):  
Yun Song Li ◽  
Jie Meng ◽  
Ye He
Keyword(s):  
Internal Model ◽  
High Speed ◽  
Control Method ◽  
Dynamic Performance ◽  
Internal Model Control ◽  
Decoupling Control ◽  
Control Effect ◽  
Model Control ◽  
Set Up ◽  
Vector Control System

Due to the structural characteristic, the dynamic performance of the high speed spindle is influenced by multi-coupled parameters. Conventional control method can’t attain the satisfied control result. So the view of internal model decoupling control of high speed motorized spindle is put forward, which can improve the performance of vector control system. In this paper, mathematical model based on internal model control of high speed spindle is set up. And voltage and current of stator are decoupled. At last, through simulation, it is proved that the method can improve the control effect and has better robustness, dynamic characteristic. Therefore, internal model decoupling control of high speed spindle is feasible and effective.

Stable control of the high-speeding magnetically suspended rotor based on extended state observer and two-degree freedom internal model control for control moment gyros with serious moving-gimbal effects

2020 ◽  
Vol 42 (14) ◽  
pp. 2733-2743
Author(s):  
Jiqiang Tang ◽  
Tongkun Wei ◽  
Qichao Lv ◽  
Xu Cui
Keyword(s):  
Internal Model ◽  
Feedback Linearization ◽  
Control Method ◽  
Fast Response ◽  
State Observer ◽  
Internal Model Control ◽  
Extended State Observer ◽  
Extended State ◽  
Control Moment ◽  
Model Control

For a magnetically suspended control moment gyro (MSCMG), which is an ideal attitude actuator for its large outputting control moment and fast response, the moving-gimbal effects due to the coupling between the moving gimbal and high-speeding rotor will make the magnetically suspended rotor (MSR) unstable. To improve control precision, both the dynamic model of MSR and the feedback linearization control are done to decouple tilting motion, and poles of the system are reconfigured to reduce control error. To suppress the varying disturbance moments caused by moving-gimbal effects, an extended state observer (ESO) is originally designed to estimate and compensate them timely and accurately. To improve system robustness, a two-degree freedom internal model control (2-DOF IMC) is researched to suppress model error. Compared with existing proportional integral derivative (PID) control method, simulations done on a single gimbal MSCMG with 200 N.m.s angular momentum indicated that this presented control method with ESO and 2-DOF IMC can suppress the moving-gimbal effects more effectively and make the rotor suspension more stable.

Modelling Flue Gas Desulfurization Using Pyrolusite Pulp in a Jet Bubbling Reactor

2009 ◽  
Vol 610-613 ◽  
pp. 85-96 ◽  
Author(s):  
Jing Dong Zhao ◽  
Shi Jun Su ◽  
Nan Shan Ai ◽  
Xiao Fan Zhu
Keyword(s):  
Flue Gas ◽  
Ph Value ◽  
Scale Up ◽  
Absorption Efficiency ◽  
Flue Gas Desulfurization ◽  
Process Conditions ◽  
Gas Temperature ◽  
Transfer Coefficients ◽  
Set Up ◽  
So2 Absorption

A mathematical model for flue gas desulfurization using pyrolusite pulp in jet bubbling reactor (JBR) was described. Firstly, based on the concept of two stages mass balance with chemical reaction, two models were set up, for jet bubbling zone and rising bubble zone, respectively, according to the construction of JBR. The models consist of two coupling differential equations and were solved simultaneously by integral and separation of the variables. Then the SO2 absorption efficiency expression was developed, considering the great discrepancy existing between the gas-side mass transfer coefficients of the jet bubbling zone and gas bubble rising zone. The final expression associates SO2 absorption efficiency with process conditions and JBR structure parameters, which can give some instruction and guidance for the study of reactor operation process. Predicted results from the theoretical model, including effect of pH value of the pulp, flue gas temperature and inlet SO2 concentration of flue gas on SO2 absorption efficiency, were found to be in good agreement with experimental data obtained in a jet bubbling reactor. The model provides a basis for the process scale up and operating guide.

scholarly journals Research on Anti-saturation Feedback Control Method for UAV Avionics System

2018 ◽  
Vol 232 ◽  
pp. 04008
Author(s):  
Xiao-Jun Zhang
Keyword(s):  
Steady State ◽  
Control Method ◽  
Control Process ◽  
System Control ◽  
State Control ◽  
Saturation Control ◽  
Disturbance Rejection Control ◽  
Feedback Control Method ◽  
Equivalent Control ◽  
Steady State Control

UAV avionics system is prone to saturation distortion under unsteady conditions, so anti-saturation control is needed. A control method of UAV avionics system based on anti-saturation feedback compensation is proposed. The anti-saturation control process of UAV avionics system is a multi-objective optimization process with multi-variables. The constrained parameter model of UAV avionics system control is constructed. Electromagnetic loss, torque, output power and other parameters are taken as constraint indexes, the original control information of UAV avionics system is treated with self-stabilization, the equivalent control circuit is designed, and the magnetic resonance transmission mode of avionics system is analyzed. An anti-saturation feedback tracking control method is used for steady-state control of the output voltage of the avionics system. The error compensation function is constructed to adjust the output adaptive parameters of the avionics system and the static anti-saturation compensator is constructed to compensate the power gain. The yaw error and the output steady-state error of the avionics system are reduced. The simulation results show that the proposed method has better output stability, lower output error, better real-time performance and better linear auto-disturbance rejection control performance.

scholarly journals Research and Application of Rubber Tree Quantitative Fertilization System Control Based on PLC

2018 ◽  
Vol 176 ◽  
pp. 01013
Author(s):  
Yeqin Wang ◽  
Yuan Zhang ◽  
Yiguo Deng ◽  
Lijiao Wei ◽  
Shengli Liu
Keyword(s):  
Natural Rubber ◽  
Control Method ◽  
Frequency Converter ◽  
Rubber Tree ◽  
Control Process ◽  
System Control ◽  
Application Process ◽  
Type Selection ◽  
Fertilization System ◽  
Selection Of

In this paper, the quantitative control method and system control process of the natural rubber forest quantitative fertilization system are introduced on the basis of the demand for the quantitative fertilization of natural rubber forest and the application process of the rubber forest fertilizing machine. The selection of PLC, frequency converter type selection and software design process are described in detail.

Experimental Study on Desulfurization Enhanced by Additive in Limestone-Gypsum FGD Process

2014 ◽  
Vol 675-677 ◽  
pp. 422-425
Author(s):  
Jun Xia Liu
Keyword(s):  
Flue Gas ◽  
Gas Flow ◽  
High Efficiency ◽  
Ph Value ◽  
Flue Gas Desulfurization ◽  
Gas Flow Rate ◽  
Lime Solution ◽  
Desulfurization Efficiency ◽  
Technical Features ◽  
Hexanedioic Acid

This Paper introduced the research background and technical features of the simulative experiments in the laboratory with the sorbent of lime solution without lime particles. By means of the effects of various influencing factors on SO2 removal efficiency were studied carefully. These parameters include gas flow rate (G), inlet SO2 concentration, liquid-to-gas ratios, the height of the packing and the additive, at the same time menstruating the pH value of the liquid flowing from the tower. To improve desulfurization efficiency of limestone in the wet flue gas desulfurization (WFGD), effect of the hexanedioic acid additive on limestone desulfurization agent were studied. The result shows that this system has advantages of high efficiency, stable, low investment and low circulating cost. The result could give a reference to optimization and will be helpful in selecting desulfurization techniques.

scholarly journals Model-Free Adaptive Control of pH Value of Wet Desulfurization Slurry under Switching of Multiple Working Conditions

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jian Liu ◽  
Xiaoli Li ◽  
Jihan Li ◽  
Kang Wang ◽  
Fuqiang Wang ◽  
...  
Keyword(s):  
Adaptive Control ◽  
Working Conditions ◽  
Ph Value ◽  
Control Process ◽  
Ph Control ◽  
Flue Gas Desulfurization ◽  
System Parameters ◽  
Model Free ◽  
Desulfurization Process ◽  
Adaptive Control Algorithm

In limestone-gypsum wet flue gas desulfurization process, the change process of pH value of slurry in absorption tower is a typical nonlinear system with time delay and various uncertainties, so it is difficult to establish an accurate mathematical model of slurry pH control process. According to the pH control process of the slurry of wet flue gas desulfurization process, a model-free adaptive control algorithm based on compact form dynamic linearization (CFDL-MFAC) is designed to realize the tracking control of the pH value of the slurry. Due to various interference factors in the pH control process of slurry in absorption tower, it is easy to cause jump change of control system parameters and even structure. Therefore, a model-free adaptive control algorithm based on switching strategy is proposed in this paper. According to different working conditions, several model-free adaptive controllers are established. The stability of the algorithm is analyzed for the two cases of fixed system parameters and jumping system parameters. It was found that the model-free adaptive controller based on the switching strategy can switch multiple controllers under the condition of system parameter jump, so as to realize the fast tracking control of the slurry pH value of the system absorption tower under different working conditions. Through this method, the overshoot can be reduced and the control quality can be improved.

scholarly journals Current Control Methods for an Asymmetric Six-Phase Permanent Magnet Synchronous Motor

Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 172 ◽  
Author(s):  
Zhihong Wu ◽  
Weisong Gu ◽  
Yuan Zhu ◽  
Ke Lu
Keyword(s):  
Permanent Magnet ◽  
Internal Model ◽  
Control Method ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Current Control ◽  
Internal Model Control ◽  
Lms Algorithm ◽  
Least Mean Square ◽  
Model Control

Via the vector space decomposition (VSD) transformation, the currents in an asymmetric six-phase permanent magnet synchronous motor (ASP_PMSM) can be decoupled into three orthogonal subspaces. Control of α–β currents in α–β subspace is important for torque regulation, while control of x-y currents in x-y subspace can suppress the harmonics due to the dead time of converters and other nonlinear factors. The zero-sequence components in O1-O2 subspace are 0 due to isolated neutral points. In α–β subspace, a state observer is constructed by introducing the error variable between the real current and the internal model current based on the internal model control method, which can improve the current control performance compared to the traditional internal model control method. In x–y subspace, in order to suppress the current harmonics, an adaptive-linear-neuron (ADALINE)-based control algorithm is employed to generate the compensation voltage, which is self-tuned by minimizing the estimated current distortion through the least mean square (LMS) algorithm. The modulation technique to implement the four-dimensional current control based on the three-phase SVPWM is given. The experimental results validate the robustness and effectiveness of the proposed control method.

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