Application of decentralized control in electrical control
the relay in PLC equivalent circuit is not the actual physical relay, it is essentially the state of memory unit. The unit status is "1", which means that the relay is on; If the status of the unit is "0", it is equivalent to the disconnection of the relay. Therefore, we call these relays "soft relays". Therefore, the number of contacts of "soft relay" is unlimited, which can be understood as programmable controller
such as Mitsubishi! M is the auxiliary relay! S state device! X signal input! Y signal output! C counter! T timer! There are some special m8000 other than this, you need to check its related instructions! And function
such as Siemens! M is the auxiliary relay! S state device! I is the signal input! Q is the signal output! AIW is analog signal input ~ aqw analog signal output! C counter! T timer! SM outside are special, but also to see the relevant instructions! To understand the purpose< The common relays can be divided into four categories:
the first category is classified according to its principle of action or structural characteristics
1. Electromagnetic relay is an electrical appliance which can realize the function of opening, closing or switching contacts by driving the movable part of the magnetic circuit by the electromagnetic attraction generated by the control current passing through the coil. Electromagnetic relay can be divided into DC electromagnetic relay, AC electromagnetic relay and magnetic holding relay< Solid state relay (SSR): SSR is a kind of all solid state device which can perform the function of opening and closing circuit like electromagnetic relay, and its input and output insulation is equivalent to that of electromagnetic relay< Hybrid relay: a relay composed of electronic components and electromagnetic relay. Generally, the input part is composed of electronic circuit, which plays the role of amplification and rectification, while the output part uses electromagnetic relay
4. High frequency relay: it is used to switch AC lines with frequency higher than 10kHz
5. Coaxial relay: it is equipped with coaxial cable, which is used to switch high-frequency and RF lines with minimum loss
6. The contact part of vacuum relay is sealed in a high vacuum container, which is used to quickly open, close or convert relays for high voltage, high frequency and radio frequency lines
7. Thermal relay: it is a relay operated by thermal effect. It can also be divided into temperature relay and electrothermal relay
8. Photoelectric relay: a relay operated by photoelectric effect
9. Polarized relay: a relay operated by the combined action of polarized magnetic field and control current through the control coil. The action direction of the relay depends on the current direction in the control coil
10. Time relay: when the input signal is added or removed, the output part needs to delay or limit the specified time to close or disconnect the relay of the controlled line
11. Reed relay: it is a kind of relay which can open, close or change the circuit by using the action of the reed which is sealed in the tube and has the al function of contact reed and armature magnetic circuit< Micro power relay: when the contact open circuit voltage is 27 V DC, the contact rated load current (resistance) is 0.1 A and 0.2 a
2. Low power relay: when the contact open circuit voltage is 27 V DC, the contact rated load current (resistance) is 0.5 A and 1 A
3. Medium power relay: when the contact open circuit voltage is 27 V DC, the contact rated load current (resistance) is 2 A and 5 a
4. High power relay: when the contact open circuit voltage is 27 V DC, the contact rated load current (resistance) is 10 A, 15 A, 20 A, 25 A, 40 a<
the third category: according to the overall dimension of the relay
1. Micro relay: the relay with the longest side dimension not more than 10 mm
2. Subminiature relay: the longest side size is larger than 10 mm, but not larger than 25 mm
3. The longest side size of small relay is greater than 25 mm, but not greater than 50 mm< The fourth type is classified according to the protection characteristics of relays.
1. Sealed relay: it is a kind of relay that uses welding or other methods to seal the contacts and coils in the enclosure, which is isolated from the surrounding media and has low leakage rate
2. Enclosed relay: a relay that encloses (unsealed) the contacts and coils in the enclosure for protection
3. Open relay: a relay that does not use a protective cover to protect the contact and coil.
The courses of electrical engineering and its automation include:
1, power system automation: power system automation mainly includes three aspects: real-time monitoring of regional dispatching, substation automation and load control. The automation of management system is realized by computer. The main projects include power instry planning management, financial management, proction management, personnel and labor management, data retrieval, design and construction, etc
Power system relay protection: the development of power system relay protection has gone through the stages of electromechanical type, rectifier type, transistor type and integrated circuit type, and now it has developed to the stage of microcomputer protection. The development history of microcomputer relay protection microcomputer relay protection refers to the relay protection based on digital computer (including microcomputer). It originated in the middle and late 1960s in Britain, Australia and the United States3. Embedded system: it is a kind of special computer system which is completely embedded in the controlled devices and designed for specific applications. According to the definition of U.K. institution of electrical engineer, embedded system is the control, monitoring or auxiliary equipment, machine or equipment used for factory operation. Unlike general-purpose computer systems such as personal computers, embedded systems usually perform pre-defined tasks with specific requirements
4. Control theory: control theory is about the theoretical research results with new ideas and new ideas in system control science and its application research results in various fields, especially in the high-tech field, but there is a serious disconnection in the civil field, that is, in real life
Power electronic technology: power electronic technology is a new electronic technology applied in the field of power, which uses power electronic devices (such as thyristor, GTO, IGBT, etc.) to transform and control electric energy. The "power" power transformed by power electronic technology can be as large as hundreds of MW or even GW, or as small as several w or even less than 1W. Different from information electronic technology, which mainly focuses on information processing, power electronic technology is mainly used for power transformationGenerally speaking, students will have a misunderstanding: what we learn in university is out of date and can't be applied in practical work
when I first entered the University, what I learned was the most basic knowledge. Therefore, it's easy to think that these things may not be used in the future. However, the development of science and technology is based on the predecessors' foundation, and the high-rise buildings rely on the incomparably solid foundation. Without silicon accumulation, we can't walk thousands of miles, and we can't build rivers without small streams. Although learning things is very basic, but graally you will find that future learning is based on the basic knowledge of these basic subjects. Just like the students who have studied engineering for four years and liberal arts for four years, there is a big difference

this major cultivates senior engineering and technical personnel with basic knowledge of engineering technology and corresponding professional knowledge of electrical engineering, and basic ability to solve problems of analysis and control of electrical engineering technology. The major of electrical engineering and automation is to cultivate wide caliber and compound senior engineering and technical personnel who can be engaged in electrical engineering and automation, computer technology application, economic management and other fields for all walks of life< Major courses of electrical engineering and Automation Major:
circuit principle, power system automation, power system relay protection, analog electronic technology foundation, digital electronic technology foundation, electromotology, high voltage technology, power system analysis, electromagnetic field and electromagnetic wave, single chip microcomputer technology, power plant electrical part, factory power supply Electrical machinery and electric drive foundation, power electronic technology, automatic control principle, computer control system, introction to system engineering, microcomputer principle and interface technology, control theory, power engineering foundation, embedded system and single chip microcomputer, PLC principle and application, power transmission technology, power system protection and control. Main subjects: Electrical Engineering, control science and engineering Computer science and technology
1. Main courses
circuit principle, electronic technology foundation, engineering electromagnetic field, software technology foundation, microcomputer technology, computer network, electrical machinery, automatic control theory, signal analysis and processing, management, engineering economics, power system (transient and steady state) analysis, power system relay protection, power system fault diagnosis, fault diagnosis, fault diagnosis, fault diagnosis, fault diagnosis and fault diagnosis Power plant electrical main system, high voltage technology, etc. Each grade can set flexible professional direction mole courses and elective courses according to social needs<
2. Degree courses
Advanced Mathematics, circuit principle, Fundamentals of electronic technology, microcomputer technology, computer network, electromotology, automatic control theory, power system analysis, power system relay protection, C language, C + +.
main practical teaching links: metalworking practice, electronic engineering practice, electrical measurement and experimental technology, computer software and hardware practice Professional comprehensive experiment, professional curriculum design, graation practice, graation design, etc< Third, employment prospects of electrical engineering and Automation Major:
Electrical Engineering and automation major is a new discipline in the field of electrical information, with its tentacles extending to all walks of life, from the design of a switch to the research of aerospace aircraft. Because it is closely related to people's daily life and instrial proction, it develops very rapidly and is relatively mature now[ 3]
this major was born in the 1970s. It was first realized in Oxford University in the UK in the DC control mode. At that time, the driving voltage of the actuator was DC, and the control voltage was also DC. The working mode of the automation system was very simple, rough, and the precision was also very low. But the control mode of DC is well known because of its long history. Naturally, people think of using DC to control AC actuator. With the emergence and maturity of high-power electronic devices such as transistors, high-power transistors and field-effect transistors, as well as the establishment of weak current and strong current control system based on modern mathematics and matrix algebra, electronic technology and automation have reached a new historical high. Although China has not been at the forefront of the world in this aspect, with the improvement of China's comprehensive national strength and the increase of foreign exchanges, we have graally narrowed the gap with developed countries. The representative ones are: 300 billion computer development per second; Mastery of nanotechnology; The application of simulation technology
Development Prospect: "automation" belongs to information instry. Information instry is known as "sunrise instry". It is the trend of today's science and technology development, which is characterized by rapid development, large demand for talents and high treatment. Therefore, as an important member of the information instry, automation also has a bright future. Second, automation has a wide range of applications
with the continuous development of China's economy and modern instry, the talent market of electrical automation technology has considerable potential. Especially in Guangdong, the continuous improvement of automation proction technology, the continuous popularization of automation procts, the application of intelligent buildings and smart home, and the continuous development of intelligent transportation provide a broad development prospect for the major of electrical automation technology.
Objectively speaking, there is no question whether different majors are better or worse. The key lies in whether they are suitable for themselves. However, most people don't know what major they are suitable for or like. This is normal. After all, they haven't contacted many social instries since they were young. They don't understand them. I think it can be considered according to my current strength and the work I may be engaged in in in the future. Science and engineering majors, especially electrical automation majors, have high basic requirements for mathematics and physics, otherwise it is difficult to reach a certain level. If the foundation is general, mechatronics will be chosen. In this way, in the mechanical and electrical aspects have a certain theoretical basis, in the future, whether engaged in mechanical, electrical, automation are certain adaptability< br />
it covers a wide range and is necessary at all times.
with the emergence and maturity of high-power electronic devices such as transistors, high-power transistors and field-effect transistors, as well as the establishment of weak current and strong current control system based on modern mathematics and matrix algebra, the electronic technology and automation have reached a new historical height. Although China has not been at the forefront of the world in this aspect, with the improvement of China's comprehensive national strength and the increase of foreign exchanges, we have graally narrowed the gap with developed countries. The representative ones are: 300 billion computer development per second; Mastery of nanotechnology; The application of simulation technology
main courses of electrical automation: motor and drive, factory electrical control technology, power electronics technology, power electronics technology practice, single chip microcomputer technology, PLC technology, electronic engineering drawing, factory power supply and distribution technology, electronic technology comprehensive training, electrical equipment, English intensive reading, professional English
the employment development prospect of electrical automation: "automation" belongs to the information instry. Information instry is known as "sunrise instry". It is the trend of today's science and technology development, which is characterized by rapid development, large demand for talents and high treatment. Therefore, as an important member of the information instry, automation also has a bright future. Second, automation has a wide range of applications. At present, almost all instrial departments can be linked with automatic control. Modern agriculture and national defense are also closely related to automation. Third, this major is very beneficial to personal development. The curriculum of this major covers a wide range, and what we learn intersects with many other subjects. This is also related to the origin of this major. Most of the automation majors come from the automatic control major of the Department of computer or electronic engineering
with the continuous development of China's economy and modern instry, the talent market of electrical automation technology has considerable potential. Especially in Guangdong, the continuous improvement of automation proction technology, the continuous popularization of automation procts, the application of intelligent buildings and smart home, and the continuous development of intelligent transportation provide a broad development prospect for the major of electrical automation technology
power electronic technology and microcomputer control technology are important parts of high-tech instry. Intelligent control electrical appliances and electrical control equipment, automatic control system and proction line are widely used in instry, agriculture, national defense and other fields, and play an important role in the national economy. Generally, graates can choose state-owned quality and technical supervision departments, research institutes, instrial and mining enterprises, etc; It can also be some foreign-funded and private enterprises. Of course, the treatment is quite considerable. If the students are strong enough and have accumulated good research results ring their study, they can start their own business and break their own sky. It should be pointed out that, because foreign research in this field is prior to ours, it is a good choice to go abroad for further study if you want to have further development and establish your leading position in this field in China.
is the widest professional in the field of employment. Mechatronics technology is a comprehensive application technology established on the basis of the combination of mechanical, optical, electrical, automatic control and detection, computer application and other disciplines. This major mainly trains intermediate engineering and technical personnel who can carry out the application of mechatronics technology and have the ability of preliminary design and development. After three years of study, the students can master the basic knowledge and necessary skills of machine, electricity and computer
I. training objectives:
this major is mainly aimed at enterprises manufacturing Mechatronics mechanical equipment and mechanical parts. It aims to cultivate those who are morally, intellectually, physically and aesthetically well-developed, have entrepreneurship, innovation spirit and good professional ethics, have certain Mechatronics basic theoretical knowledge, intermediate professional skills and good professional ethics, and can be engaged in the installation and maintenance of mechatronics equipment Senior technical talents for debugging, operation, maintenance, management and technical transformation< Main courses:
mechanical drawing and CAD, mechanical design, mechanical manufacturing technology, electrical and electronic technology foundation, hydraulic and pneumatic, electrical control and PLC application, sensor and detection technology, mechatronics technology foundation, mechatronics technology application, microcomputer principle and interface technology, numerical control processing technology and programming, etc< Third, skill training:
fitter training, mapping, mechanical design foundation course design, mechanical and electrical control technology course design, PLC, SCM course design, proction practice and graation practice and design, etc
graates of this major should obtain the following certificates:
(1) first level certificate of national computer (or other certificates of the same level)
(2) first level certificate of foreign language proficiency test (or other certificates of the same level)
(3)
intermediate certificate of CAD vocational and technical training
(4) Intermediate Certificate of fitter or electrician (or other certificates of the same level)
(4) experiment Introction to training place:
the existing professional software laboratory of this major can carry out the teaching of numerical control machine tool operation and processing simulation,
Master
cam
and electrical CAD design. There are many training bases inside and outside the school, including: CNC machine tool operation and machining training base, lathe fitter training base, electric welding training base, mold processing training base, electronic circuit laboratory, electrician laboratory, etc< With the economic globalization, China's manufacturing instry has become the core of the national economy, and mechatronics has become the "engine" of the development of manufacturing instry, and the demand for Mechatronics technical personnel has increased significantly
mainly for enterprises and companies in the Pearl River Delta, engaged in processing and manufacturing instry, home appliance proction and after-sales service, CNC machine tool equipment use and maintenance, property automation management system, mechanical and electrical proct design, proction, transformation, technical support, as well as mechanical and electrical integration equipment installation, debugging, repair, sales and management; The common machine tool numerical control refits and so on. Yangjiang region is undertaking the instrial transfer of the Pearl River Delta while building an energy base in Guangdong. The large-scale energy projects such as Yangjiang Nuclear Power Plant and Yangjiang thermal power plant have been put into operation, and a large number of practical talents of Mechatronics are needed. The employment prospect of this major is good
the above is for reference only. I wish you success in your studies
a wide range of employment, mainly engaged in equipment installation, commissioning, maintenance, sales and management; The NC refitting of common machine tools is a kind of compound talents needed by the society.
