Improved Model of an Intermediate Point Enthalpy Control System for Enhancing Boiler Efficiency

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Zihao Yang ◽  
Yanping Zhang ◽  
Wei Gao
Keyword(s):  
Control System ◽  
Control Method ◽  
Control Object ◽  
Stable Operation ◽  
Feed Water ◽  
Intermediate Point ◽  
Control Quality ◽  
Boiler Efficiency ◽  
Improved Model

Control quality of an once-through boiler’s water-fuel ratio (WFR) and main-steam temperature are heavily influenced by the control quality of the once-through boiler’s intermediate point enthalpy (IPE), and it is also related to the economic and stable operation of the a once-through boiler. In order to control the IPE in a better way and to increase boiler efficiency, an improved model of IPE control system was built in this paper, matlab/simulink is used to build the IPE control system model based on a 600 MW supercritical unit, and the mechanism model of the control object is built in the same time. The feedforward of the feed-water temperature is brought to this model to increase the control rate. The control method of amendments to the amount of coal and the control method of amendments to the amount of feed-water are combined by the means of fuzzy control to solve the problem of the contradiction of the responding speed of the IPE and the separation interface’s stability of the steam-water separator. The simulation results show that the improved control method has better control effect and higher boiler efficiency was obtained as well.

Application of Single Neuron Adaptive PID Controller in Flow Control System

2014 ◽  
Vol 602-605 ◽  
pp. 1052-1055 ◽  
Author(s):  
Ze Kang ◽  
Cheng Qiang Yin ◽  
Shao Min Teng
Keyword(s):  
Control System ◽  
Flow Control ◽  
Pid Controller ◽  
Single Neuron ◽  
Control Method ◽  
Dynamic Performance ◽  
Oxide Concentration ◽  
Flow Control System ◽  
Self Learning

Oxide concentration at reactor inlet is one of the most important factor effecting the quality of ethylene oxide concentration. A control method with adaptive PID of single neuron is propose using the parameter self-learning with adaptive PID controller of single neuron for the oxide flow control system. The simulation results show that this design scheme has a better dynamic performance than traditional PID scheme to verify the feasibility of this method.

scholarly journals DEVELOPMENT OF STRUCTURAL SCHEMES AND OPERATION ALGORITHMS FOR THE AUTOMATIC CONTROL SYSTEM OF A MULTIFUNCTIONAL ENERGY COMPLEX

2021 ◽  
Vol 445 (1) ◽  
pp. 82-90
Author(s):  
G. Kalimbetov ◽  
A. Toigozhinovа ◽  
W. Wojcik
Keyword(s):  
Control System ◽  
Automatic Control ◽  
Control Systems ◽  
Dynamic Control ◽  
Control Object ◽  
Control Device ◽  
Automatic Control Systems ◽  
Operating Modes ◽  
Quality Of Control

Among the promising automatic control systems, logical-dynamic control systems that change both the structure and parameters of the control device using switches formed on the basis of a certain logical algorithm have proven themselves well. The use of logical algorithms as part of MACS subsystems for complex technical objects makes it possible to increase the static and dynamic accuracy of control due to purposeful qualitative and quantitative changes in the control signal. This approach will give the control system fundamentally new properties that allow to fully take into account the nature and dynamics of the movement of the control object. When developing existing logical control algorithms, the issues of their application for multi-connected and multifunctional objects control were not considered. Common to existing logical algorithms is that when switching the structure and/or changing parameters, only the dynamics of its own subsystem is taken into account, which is unacceptable in the case of multi-connected dynamic object control, since cross-links have a significant impact on the quality of control. Thus, the problem of synthesis of logical algorithms for multi-connected objects control is an actual theoretical and applied problem. Despite the considerable amount of research conducted in this area, the application of logical algorithms for complex multidimensional objects control is not sufficiently considered, and there is no unified design concept for this type of MACS, taking into account the required quality of functioning in various operating modes. In this regard, there is a need to synthesize algorithms for logical multi-connected control that form control signals in order to coordinate the actions of all separate MACS subsystems in accordance with new external conditions and operating modes. The problem under consideration determined the purpose of this work and the research objectives.

Direct Slip Linear Control of Bearingless Induction Motor Based on Space Vector Modulation

2011 ◽  
Vol 317-319 ◽  
pp. 590-594
Author(s):  
Xian Xing Liu ◽  
Xiao Yan Shao ◽  
Ming Yi Chen
Keyword(s):  
Control System ◽  
Induction Motor ◽  
Control Method ◽  
Radial Force ◽  
Linear Control ◽  
Stable Operation ◽  
Space Vector Modulation ◽  
Space Vector ◽  
Vector Modulation ◽  
The Impact

Due to the complex nonlinear coupling characteristics of non-bearing induction motor control system, the basic requirements to maintain the stable operation of the bearingless induction motor is to achieve the decoupling control between electromagnetic torque and radial force, and it is also difficult to design efficient and reliable control system in this field. In this paper, the entire control system is divided into the rotating control system and suspension control system, a control method direct slip linear control based on space vector modulation (DSLC-SVM) is put forward. As to rotating part, because of the direct control of the slip, the flux magnitude deviation and the current total harmonic distortion (THD) can be reduced. As to suspension part, the voltage PWM controlled inverter is adopted to improve the utilization of DC bus voltage and reduce the impact of high harmonics. At last, by comparing the simulation results with traditional control methods, the feasibility and correctness of this method are demonstrated.

The Automatic Control System Applied to Food Packing Production Line Based on STEP7-MICRO/WIN

2011 ◽  
Vol 63-64 ◽  
pp. 273-276
Author(s):  
Wei Wang ◽  
Jian Hua Ren
Keyword(s):  
Control System ◽  
Food Production ◽  
Control Object ◽  
Centralized Control ◽  
Packaging System ◽  
Practical Applications ◽  
Plc Control ◽  
Multiple Devices ◽  
Programming Software

In this paper， we introduce a food production and packaging system. This system includes many processes, namely, mixing, blending, molding, drying, packaging, and relates to multiple devices. To ensure the quality of food production and packaging, it needs coordination of all procedures and controls based on process requirements to achieve different objectives, so we use PLC centralized control in the food production and packaging system. According to the control object, we allocated the PLC address and choose the PLC of Siemens S7-200. On the basis of control tasks, we designed a control flowchart and programmed for PLC control system of Siemens S7-200 using STEP7-MICRO/WIN programming software .The practical applications have proved the good results.

scholarly journals THE INFLUENCE OF THE INPUT INDUCTANCE ON THE QUALITATIVE INDICATORS OF ACTIVE CONTROLLED RECTIFIER

2021 ◽  
pp. 18-23
Author(s):  
Denis Krylov ◽  
Olga Kholod
Keyword(s):  
Control System ◽  
Electromagnetic Compatibility ◽  
Modulation Frequency ◽  
Frequency Converter ◽  
Voltage Source ◽  
Stable Operation ◽  
Active Rectifier ◽  
Semiconductor Converters ◽  
Three Phase

The main part of electricity is used by industrial plants in a converted form and the use of semiconductor converters is growing rapidly. The requirements for the quality of semiconductor converters are increased. And their impact on the power supply, load and related consumers is increased too. One of the most popular converters in the segment of low and medium power drives is a frequency converter made on the basis of a three-phase stand-alone voltage inverter. A significant disadvantage of such converters is the use of a diode rectifier at the input of the circuit, which has disadvantages as the inability to recover electricity to the mains in the mode of dynamic braking of an induction motor and significant distortions of the mains current. These disadvantages can be eliminated by using an active rectifier instead of a diode rectifier, which provides a sinusoidal shape of the mains current in phase with the mains voltage and the possibility of bidirectional energy exchange with the load. The efficiency of the active rectifier-voltage source is determined by the selected control algorithm of the circuit switches and the correct task of the inductance of the input choke. A mathematical model of a three-phase active rectifier-voltage source, working with a fixed modulation frequency with a vector algorithm for building a control system and analysis of the influence of the input inductance on the quality of its work was created. From the simulation results it became obvious that the proposed structure of the control system provides stable operation of the converter and acceptable standards for electromagnetic compatibility with the mains at a fixed modulation frequency; the proposed algorithm for calculating the value of the input inductances allows you to correctly select their allowable value, and obtained in the simulation of the dependence allows you to most accurately determine the value of the input inductances on the allowable level of distortion of mains current and supply voltage.

scholarly journals Automatic Temperature Control System on Smart Poultry Farm Using PID Method

2021 ◽  
Vol 1 (1) ◽  
pp. 37-43
Author(s):  
Agung Enriko ◽  
Ryan Anugrah Putra ◽  
Estananto
Keyword(s):  
Control System ◽  
Temperature Control ◽  
Pid Control ◽  
Control Method ◽  
Weather Conditions ◽  
Temperature Control System ◽  
Poultry Farm ◽  
Control Approach ◽  
Calibration Accuracy

Chicken farmers in Indonesia are facing a problem as a result of the country's harsh weather conditions. Poultry species are very susceptible to temperature and humidity fluctuations. As a result, an intelligent poultry farm is necessary to intelligently adjust the temperature in the chicken coop. A smart poultry farm is a concept in which farmers may automatically manage the temperature in the chicken coop, thereby improving the livestock's quality of life. The purpose of this research is to develop a chicken coop prototype that focuses on temperature control systems on smart poultry farms via the PID control approach. The PID control method is expected to allow the temperature control system to adapt to the temperature within the cage, thereby assisting chicken farmers in their tasks. The sensor utilized is a DHT22 sensor with a calibration accuracy of 96.88 percent. The PID response was found to be satisfactory for the system with Kp = 10, Ki = 0, and KD = 0.1, and the time necessary for the system to reach the specified temperature was 121 seconds with a 1.03 % inaccuracy.

The Controller of DFIG Power Fed into the Grid Basing on the Rotor Similar Signal Method

2013 ◽  
Vol 415 ◽  
pp. 245-249
Author(s):  
Thang Nguyen Trong ◽  
Ban Nguyen Tien ◽  
Hai Nguyen Thanh ◽  
Hai Nguyen Hoang
Keyword(s):  
Control System ◽  
Reactive Power ◽  
Control Object ◽  
Active Power ◽  
Time Response ◽  
Pid Controllers ◽  
Excitation Control ◽  
Signal Method

This paper presents and analyses characteristics of the excitation control of DFIG connected to the grid basing on the rotor similar signal method. It also identifies the control object and then proposes the controllers of the active power and the reactive power of DFIG fed into grid. There are two PID controllers used to independently control the active power and the reactive power. The parameters of the PID can be changed and adjusted by the fuzzy tuner to improve the quality of system. Basing on this control system, the quality of the system is good; such as time transition and time response of this system are very small in comparison with those of the system of previous researches.

The Use of Adaptive Inverse Control in Cascade STATCOM Modulated by PAM+PWM

2013 ◽  
Vol 448-453 ◽  
pp. 2175-2179
Author(s):  
Luan He ◽  
Xin Wang ◽  
Li Dan Zhou ◽  
Yi Hui Zheng ◽  
Li Xue Li ◽  
...  
Keyword(s):  
Control System ◽  
Control Method ◽  
Mathematic Model ◽  
Time Varying ◽  
Adaptive Inverse Control ◽  
Inverse Control ◽  
Switching Losses ◽  
Harmonic Elimination ◽  
Harmonic Ratio

In order to lower the switching losses and harmonic ratio, improve the precision of the STATCOM in the same time, the adaptive inverse control based on PAM+PWM method is proposed in this paper. The combination of PAM+PWM method is presented to enable the system to achieve the quality of low switching losses and good harmonic elimination effect. Furthermore, considering the nonlinear and time-varying characteristics which are caused by the introduction of the PAM and PWM method, an adaptive inverse control method is designed to adjust the parameters of the nonlinear mathematic model constantly to improve the precision of the control system. The results of simulation show the correctness of the proposed method.

Research on Fuzzy Control System of the Water Level for Steam Generator

2011 ◽  
Vol 383-390 ◽  
pp. 4184-4188
Author(s):  
Yong Sheng Zhang ◽  
Yun Yi Ma
Keyword(s):  
Fuzzy Logic ◽  
Control System ◽  
Fuzzy Control ◽  
Water Level ◽  
Steam Generator ◽  
Control Method ◽  
Effective Control ◽  
Level Control ◽  
Time Lagged

In order to improve the control quality of the water level for steam generator, a fuzzy level controller for steam generator is designed based on the fuzzy logic principle. The fuzzy logic toolbox and Simulink module of Matlab software are used for the modeling of the water level control system of steam generator. The operating condition of reducing load is calculated. Simulation result shows that the fuzzy control has such virtues as smaller overshoot, shorter regulating time and stronger robustness than the conventional three-element PID control. Fuzzy control is especially effective for nonlinear system like steam generator with multivariable, large time lagged and strong coupling. It is a very effective control method with widely application prospect.

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