Modularization Research And Application Of Digital Logic Control System Of Heat Exchanger Unit

With the high-speed and high-quality development of economy,green development concepts such as clean,low-carbon,resource conservation and sustainable development have gradually penetrated into every corner of industrial development.Heat exchange,as a characteristic industry in the north cold areas of our country,has a great significance in energy production and utilization and improvement of residents’ quality of life.After decades of development of the heat exchanger industry in our country,there are still a series of bottleneck problems,such as heat exchange engine control system relying on foreign imported components,slow supply,difficulties in maintenance,high cost and other factors restrict the development of industrial technology.In this paper,for the building panel heat exchange unit of urban central heating system,Field Programmable Gate Array(FPGA)is adopted as the main control chip of the system,and the optimal parameter third harmonic injection SPWM algorithm is selected as the system frequency conversion control scheme.Research and design efficient modular equipment.This paper mainly carries out the following research work:First of all,the mathematical model of the frequency conversion device of the heat exchange unit is established,the generation mechanism of harmonics is analyzed,and the control principle of SPWM is studied.The simulation model is built in the MATLAB/Simulink environment for simulation analysis.The simulation results show that the output waveform of conventional SPWM is still fluctuating and burring due to the interference of harmonics in the system.In view of the low voltage utilization rate in the system,based on the conventional SPWM control,the optimal parameters of three-harmonic injection SPWM control are proposed,and its basic principle is introduced.The optimal conditions of harmonic injection are deduced.A simulation model is built in MATLAB/Simulink environment,and the simulation results are compared and analyzed with the conventional SPWM control.The results show that after injecting third harmonic,the voltage utilization rate is obviously improved,and the harmonic content is obviously reduced in the spectrum diagram,which verifies the feasibility of SPWM control with optimal parameters.Secondly,the logic control experiment platform of heat exchanger unit is built.In the circuit part,the main control board module,frequency conversion control module,input and output module,signal output module,communication module and power module are designed by Altium Designer.In the part of control strategy,the traditional SPWM control and the optimal parameter three harmonic injection SPWM control are designed by Vivado platform,the comparison output module and the dead zone control module are written,the modulated wave generation module is designed by invoking IP core,and the key module,led control and frequency control module are defined.After the design of each module is completed,two kinds of simulation verification are realized under Vivado platform to ensure the feasibility of the program.The debugging and simulation analysis of the completed modules are carried out under Vivado platform,and the data files are generated and written into Artix-7 series development board.After connecting 180 W three-phase asynchronous motor and observing under oscilloscope,it is found that compared with the conventional SPWM control,the output waveform fluctuation,burr and other problems are effectively improved by introducing the optimal parameter third harmonic injection SPWM control.Finally,the corresponding man-machine interface is configured for the control system of the heat exchange unit to achieve efficient management of users,operation mode,data maintenance,drive control and so on.A remote monitoring platform based on Microsoft visual studio is developed and various measuring devices are configured for the digital and analog quantities that need to be monitored during operation.The experimental prototype carried out a series of frequency conversion control experiments with resistive load and motor load as control objects.On the premise of successful resistive frequency conversion experiment,normal operation could be ensured after the motor frequency conversion experiment.Meanwhile,the comparison of output line voltage of the motor controlled by traditional SPWM control and optimal parameter three harmonic injection SPWM was further made,and the results showed that the output waveform was smooth and stable.It has better control effect and achieves the expected goal.The modularization control strategy of Verilog HDL language is studied in this paper.Miniaturized control equipment under FPGA technology;After comprehensive analysis of the control system and performance indicators of heat exchangers currently on the market,based on FPGA technology,Verilog HDL language is used to achieve the optimal parameter third-harmonic injection SPWM control,Altium Designer is used to design the hardware circuit,and the corresponding peripherals are configured for the system.The control system integrates the advantages of miniaturization and modularization,and has good engineering application value in practical application.