scholarly journals Electronic Expansion Valve Experimental System Debugging Solution Based on PI Control Algorithm on Single-Tube Heat Exchange Experimental Platform

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 139
Author(s):  
Jinfeng Wang ◽  
Wanying Chang ◽  
Jing Xie
Keyword(s):  
Heat Exchange ◽  
Control Algorithm ◽  
Experimental System ◽  
System Stability ◽  
Process Time ◽  
Pi Control ◽  
Single Tube ◽  
Experimental Platform ◽  
Functional Parameters ◽  
Expansion Valve

In this paper, the electronic expansion valve (EXV) on the single-tube heat exchange experimental platform was used as a research object. Firstly, the EXVs were selected according to the experimental requirements, and the functional parameters were set. Subsequently, the effective opening ranges of the EXVs were determined by manual control, and the control effects of the EXVs installed at the front and back ends of the test section were compared. Finally, by self-tuning and optimizing the best response curves, the proportional and integral coefficients suitable for the experimental platform were obtained; thus, the automatic intelligent control of EXV based on the proportional integral (PI) control algorithm was realized. From setting EXV functional parameters to realizing PI control, an appropriate experimental system-debugging solution for the whole process could be obtained. Based on the solution, the system stability could be improved, and the transition process time could be shortened. Furthermore, the solution also provided a method to guarantee the accuracy of experimental data and could be applied to the debugging of similar experimental systems.

COMPUTER SIMULATION OF FLOW IN CORRUGATED CHANNEL OF PLATE HEAT EXCHANGER

2020 ◽  
pp. 51-58
Author(s):  
Л. А. Кущев ◽  
В. Н. Мелькумов ◽  
Н. Ю. Саввин
Keyword(s):  
Computer Simulation ◽  
Heat Exchanger ◽  
Heat Exchange ◽  
High Speed ◽  
Exchange Process ◽  
Plate Heat Exchanger ◽  
System Stability ◽  
Plate Heat ◽  
Corrugated Channel ◽  
Heat Exchange Process

Постановка задачи. Рассматривается теплообменный процесс, протекающий в модифицированном гофрированном межпластинном канале интенсифицированного пластинчатого теплообменного аппарата с повышенной турбулизацией теплоносителя. Необходимо разработать компьютерную модель движения теплоносителя в диапазоне скоростей 0,1-1,5 м/с и определить коэффициент турбулизации пластинчатого теплообменника. Результаты. Приведены результаты компьютерного моделирования движения теплоносителя в межпластинном гофрированном канале оригинального пластинчатого теплообменного аппарата с помощью программного комплекса Аnsys . Определены критерии устойчивости системы. Выполнено 3 D -моделирование канала, образуемого гофрированными пластинами. При исследовании процесса турбулизации были рассмотрены несколько скоростных режимов движения теплоносителя. Определен коэффициент турбулизации Tu, %. Выводы. В результате компьютерного моделирования установлено увеличение коэффициента теплопередачи К, Вт/(м ℃ ) за счет повышенной турбулизации потока, что приводит к снижению металлоемкости и уменьшению стоимости теплообменного оборудования. Statement of the problem. The heat exchange process occurring in a modified corrugated interplate channel of an intensified plate heat exchanger with an increased turbulence of the heat carrier is discussed. A computer model of the coolant movement in the speed range of 0.1-1.5 m/s is developed and the turbulence coefficient of the plate heat exchanger is determined. Results. The article presents the results of computer modeling of the coolant movement in the interplate corrugated channel of the original plate heat exchanger using the Ansys software package. The criteria of system stability are defined. 3D modeling of the channel formed by corrugated plates is performed. In the study of the process of turbulence several high-speed modes of movement of the coolant were considered. The turbulence coefficient Tu, % is determined. Conclusions. As a result of computer simulation, an increase in the heat transfer coefficient K, W/(m ℃) was found due to an increased turbulization of the flow, which leads to a decrease in metal consumption and a decrease in the cost of heat exchange equipment.

scholarly journals Research of Active Power Filter Modeling with Grid Impedance in Feedback Linearization and Quasi-Sliding Mode Control

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Zeyu Shi ◽  
Yingpin Wang ◽  
Yunxiang Xie ◽  
Lanfang Li ◽  
Xiaogang Xu
Keyword(s):  
Sliding Mode Control ◽  
Feedback Linearization ◽  
Control Algorithm ◽  
Sliding Mode ◽  
Active Power Filter ◽  
Active Power ◽  
Pi Control ◽  
Power Filter ◽  
Mode Control ◽  
Grid Impedance

Active power filter (APF) is the most popular device in regulating power quality issues. Currently, most literatures ignored the impact of grid impedance and assumed the load voltage is ideal, which had not described the system accurately. In addition, the controllers applied PI control; thus it is hard to improve the compensation quality. This paper establishes a precise model which consists of APF, load, and grid impedance. The Bode diagram of traditional simplified model is obviously different with complete model, which means the descriptions of the system based on the traditional simplified model are inaccurate and incomplete. And then design exact feedback linearization and quasi-sliding mode control (FBL-QSMC) is based on precise model in inner current loop. The system performances in different parameters are analyzed and dynamic performance of proposed algorithm is compared with traditional PI control algorithm. At last, simulations are taken in three cases to verify the performance of proposed control algorithm. The results proved that the proposed feedback linearization and quasi-sliding mode control algorithm has fast response and robustness; the compensation performance is superior to PI control obviously, which also means the complete modeling and proposed control algorithm are correct.

The Research about the Wind Turbines Pitch Control

2013 ◽  
Vol 773 ◽  
pp. 87-90
Author(s):  
Chen Wang ◽  
De Zhou Meng ◽  
Xu Fang Bo
Keyword(s):  
Wind Power ◽  
Pid Control ◽  
Control Algorithm ◽  
Uneven Distribution ◽  
Pitch Control ◽  
Experimental Platform ◽  
Simulation Results ◽  
Pitch System ◽  
Fan Blade ◽  
Variable Pitch Control

Based on the background of wind power, considering the wind blade sweep area on the uneven distribution, this paper is using the PID control algorithm to control the pitch system. At the same time, this paper is using Siemens SCL to programming, simulating on the experimental platform. Simulation results show the validity of the theory and the feasibility of the system, realizing variable pitch control of fan blade.

scholarly journals PID Controller Implemented in Festo CDPX

2019 ◽  
Vol 260 ◽  
pp. 02008
Author(s):  
Primož Podržaj
Keyword(s):  
Control Systems ◽  
Pid Controller ◽  
Control Algorithm ◽  
Closed Loop ◽  
Pi Control ◽  
Programmable Logic ◽  
Educational Tool ◽  
Level Control ◽  
Loop Control ◽  
Machine Interface

In this paper, we describe the procedure for the implementation of the PID controller in the Festo CDPX operator unit. These units enable the execution of the control algorithm and human machine interface in a single unit. In our laboratory the unit is used to teach the students about the basics of control systems. For this purpose, one of the most common closed loop control systems for the education purposes was selected. It is a water level control system. In this paper the design of the whole system is presented. The need for a PI control algorithm is also explained. The programming of the operator unit CDPX, both in Festo CoDeSys and Designer Studio is explained. Such a simple system has turned out to be a great educational tool for Control Theory and Programmable Logic Controller related subjects.

Experimental Analysis on PV/T-SAHP Performance under the Influence of the Electronic Expansion Valve

2013 ◽  
Vol 641-642 ◽  
pp. 117-122
Author(s):  
Hai Tao Wang
Keyword(s):  
Solar Radiation ◽  
Experimental Analysis ◽  
System Performance ◽  
System Stability ◽  
Pv Module ◽  
Expansion Valve ◽  
Compressor Power ◽  
Maximum Opening

Under different Electronic Expansion Valve (EXV)opening degree at the fixing frequency of 50hz of the compressor，we had test the system performance. When the cooling refrigerant influence to the PV module and the heating air influence to the collector／evaporator reached the balance，the photoelectric efficiency achieved the maximum．When the EXV opening degree fixing, with the raising of the solar radiation, the compressor power values appeared oscillation，and the oscillation was especially evident when the EXV at the maximum opening degree． So we put forward the PV/T-SAHP system stability principle．At the same time，we found that the key of the PV／T-SAHP research is to discover the relation between the solar radiation and the superheat of collector／evaporator．

Rule-Based Alternator Control Using Predicted Velocity for Energy Management Strategy

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Jaewook Shin ◽  
Haksu Kim ◽  
Seungeon Baek ◽  
Myoungho Sunwoo ◽  
Manbae Han
Keyword(s):  
Fuel Consumption ◽  
Energy Management ◽  
Control Algorithm ◽  
Internal Combustion Engines ◽  
Electrical Energy ◽  
Control Mode ◽  
Pi Control ◽  
Electrical System ◽  
Energy Management Strategy ◽  
Rule Based

AbstractThe market concern of improvement of vehicle safety and its convenience to drive a vehicle has resulted in the growth of the demand for vehicular electronic equipment. This trend requires additional power in the vehicle and thus makes prone to the increase of fuel consumption for vehicles equipped with internal combustion engines. To minimize this fuel consumption, an efficient energy management (EM) strategy for the electrical system of alternator and battery is required. This paper proposes a successful EM strategy based on the rule-based alternator control using predictive information. The proposed strategy reduces fuel consumption by charging batteries using the residual kinetic energy during deceleration. In particular, we predict electrical energy that is recovered by the residual energy using a Markov chain-based velocity prediction algorithm. The accommodation of predicted electrical energy and current vehicle information determines one of the three predefined control modes, such as charge, hold, and discharge, depending on vehicle driving states. This control mode determines the power generation from the alternator and controls the amount of torque to the vehicle electrical system. The proposed strategy is verified through simulation and experiment. The simulation with the new EM strategy is validated as comparing the operation difference with a conventional proportional-integral (PI) control algorithm under the same driver behaviors. Further validation in real vehicle driving experiment shows that fuel consumption was reduced by 2.1% compared to the conventional PI control algorithm.

Nonlinear Force/Pressure Tracking of an Electro-Hydraulic Actuator1

1998 ◽  
Vol 122 (1) ◽  
pp. 232-236 ◽  
Author(s):  
Rui Liu ◽  
Andrew Alleyne
Keyword(s):  
Control Algorithm ◽  
Experimental System ◽  
Hydraulic Actuator ◽  
Parameter Uncertainties ◽  
Friction Modeling ◽  
Parameter Adaptation ◽  
Standard Parameter ◽  
Nonlinear Force ◽  
Adaptation Scheme ◽  
Force Pressure

In this paper, a Lyapunov-based control algorithm is developed for the force/pressure tracking control of an electro-hydraulic actuator. The controller relies on an accurate model of the system. To compensate for the parameter uncertainties, a standard parameter adaptation based on Lyapunov analysis is applied. The control law is coupled with the adaptation scheme and applied to an experimental system. Friction modeling and compensation for pressure tracking are discussed and experimental results shown. The results show that the nonlinear control algorithm together with the adaptation scheme gives a good performance for the specified task. [S0022-0434(00)00501-3]

scholarly journals Experimental Validation of a Sliding Mode Control for a Stewart Platform Used in Aerospace Inspection Applications

Mathematics ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 2051
Author(s):  
Javier Velasco ◽  
Isidro Calvo ◽  
Oscar Barambones ◽  
Pablo Venegas ◽  
Cristian Napole
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
A Priori ◽  
Absolute Error ◽  
Stewart Platform ◽  
System Stability ◽  
Pi Control ◽  
Positioning Systems ◽  
Control Approach ◽  
Mode Control

The authors introduce a new controller, aimed at industrial domains, that improves the performance and accuracy of positioning systems based on Stewart platforms. More specifically, this paper presents, and validates experimentally, a sliding mode control for precisely positioning a Stewart platform used as a mobile platform in non-destructive inspection (NDI) applications. The NDI application involves exploring the specimen surface of aeronautical coupons at different heights. In order to avoid defocusing and blurred images, the platform must be positioned accurately to keep a uniform distance between the camera and the surface of the specimen. This operation requires the coordinated control of the six electro mechanic actuators (EMAs). The platform trajectory and the EMA lengths can be calculated by means of the forward and inverse kinematics of the Stewart platform. Typically, a proportional integral (PI) control approach is used for this purpose but unfortunately this control scheme is unable to position the platform accurately enough. For this reason, a sliding mode control (SMC) strategy is proposed. The SMC requires: (1) a priori knowledge of the bounds on system uncertainties, and (2) the analysis of the system stability in order to ensure that the strategy executes adequately. The results of this work show a higher performance of the SMC when compared with the PI control strategy: the average absolute error is reduced from 3.45 mm in PI to 0.78 mm in the SMC. Additionally, the duty cycle analysis shows that although PI control demands a smoother actuator response, the power consumption is similar.

A Control Method for Active Power Filters with Three-Level NPC Inverter

2011 ◽  
Vol 268-270 ◽  
pp. 428-433
Author(s):  
Chen Guo ◽  
Cun Bing Gui ◽  
Zhong Ren Chen
Keyword(s):  
Control Algorithm ◽  
Control Method ◽  
Sampling Period ◽  
Active Power ◽  
Pi Control ◽  
State Variables ◽  
Active Power Filters ◽  
Power Filters ◽  
Repetitive Nature ◽  
Periodic Error

This paper researches control problem for active power filters with three-level NPC inverter and proposes a novel PI control algorithm for tracking harmonic command current. This novel PI control algorithm can suppress the periodic error in the whole system to achieve zero steady error tracking. In this scheme, the state variables are estimated with a state observer to cancel the delay of one sampling period in this digital control system. Harmonic current is predicted with a repetitive algorithm simultaneity, which makes use of the repetitive nature of load current. The controller is analyzed and designed in the paper, and the experiment results illustrate that this APF can be controlled in a satisfactory way.

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