Essay on Physics

Physics is the study of the most general laws of the motion of matter and the basic structure of matter, and is one of the most sophisticated natural science disciplines today. The following is a sample of my essay on Essays in Physics , welcome to read it!

Essay on Physics 1

Try to talk about the teaching of electrodynamics course in physics

Dynamics of electromagnetic phenomena of the classical theory of dynamics. Often also referred to as classical electrodynamics, electrodynamics is its short form. It studies the basic properties of electromagnetic fields, the laws of motion and the interaction of electromagnetic fields and charged matter.

First, the fundamental concept of course teaching

First, in teaching to respect the subjectivity of Mr. Learning, instructor teaching dominance, one-sided development of Mr. Blindness, automaticity, inventiveness. Secondly, ? Electrodynamics? Course belongs to the professional foundation courses, teaching content arrangement in addition to let Mr. learn the fundamental knowledge of the course, the fundamental practice, the fundamental thinking, and other branches of physics also has the relationship between personality and characteristics. For this characteristic, teachers should pay attention to guide Mr. similarity abstract thought in teaching. Third, teaching should highlight the exploratory teaching methods, change the traditional teaching form, the maximum integration of information technology and electrodynamics courses, the use of a variety of ancient educational wrist optimization of the teaching process, the implementation of revelation, exploratory, discussion, small manufacturing and other teaching methods, to cultivate Mr. innovative thinking and innovative ideas.

Second, in the teaching of this course should do the following

1. teaching content should be practical contact practice

? Electrodynamics? As a professional subject course, is a teacher training colleges and universities, physics majors in the basic practical courses. Teaching requires Mr. master the fundamental knowledge of the course, the basic facts and fundamental principles, so that Mr. deepen the understanding of the knowledge taught, more in-depth view of the practical use of electrodynamics value, to achieve the purpose of learning to use, and at the same time to enhance Mr. analysis of the results of the results, the ability to deal with the results.

2. Pay attention to the subjectivity of Mr. learning and collective cultivation

From the design of the course to the evaluation of the various links, pay attention to carry forward the leading role of teachers in the teaching of the same 134 Reform of the curriculum March 2016, should pay special attention to the performance of Mr. learning the main position, in order to fully develop Mr. enthusiasm and explore the learning potential. Requirements Mr. can initially analyze the consumption, life in the electrodynamic achievements, in order to enhance Mr. analysis of achievements and the ability to deal with achievements. In the study of electrodynamics using mathematical tools to deal with the results, so that Mr. view of the intimate relationship between mathematics and physics, and to cultivate Mr. use of mathematical tools to deal with the physical results of the ability. Cultivate Mr. self-learning ability, the important thing is not to teach the content, but to teach Mr. learning methods. To pay full attention to the collective differences in the interests, expertise and fundamentals of Mr., tailored to the needs of the students, based on this differentiation to determine the learning objectives and evaluation methods, and put forward the corresponding teaching recommendations. Course specifications in the course design, teaching programs, program development, content selection and teaching evaluation, etc., for teaching, learning to provide a choice and development of space.

3. The use of a variety of ancient educational wrists to optimize the teaching link

Fully apply the ancient teaching wrists, carry forward the disadvantages of information technology teaching, to strengthen Mr. Learning interest, to further strengthen the need to master the knowledge points, broaden the knowledge base, to strengthen Mr. Theoretical operation skills, to cultivate the way of thinking of the superstitions so that Mr. Can better master the ? Electrodynamics? Course knowledge touched by the relevant superstition approach, and effectively enhance their ability to find results, analyze the results, deal with the results.

4. Have good experimental conditions, and fully guarantee the quality of experimental and theoretical training

Encourage Mr. scientific research and theoretical training, and participate in various types of scientific and technological competitions. Experimental classes and theoretical training should pay attention to cultivate Mr. logical thinking, inventive thinking, full application of physics, electronic competitions and other innovative platforms to promote the teaching of electrodynamics courses.

Third, the course learning strategy to explore

First, for ? Electrodynamics? is the characteristics of the actual basic course, Mr. must adhere to the pre-course pre-study, pre-study process unconsciously put forward the results. Classroom teaching is used to explore the classroom teaching method, that is, each class highlights a theme, speak clearly on the penetration of the relevant principles of knowledge, each theme through a variety of ways of teacher-student interactions, the instructor in a timely manner to understand, deal with Mr. Doubtful achievements, in order to strengthen Mr. Learning Interests. Second, the traditional board, electronic courseware, network and video combination of teaching wrists. Such as the combination of in-class lectures and extracurricular discussions and manufacturing, the combination of basic practical teaching and lectures on the frontiers of the discipline, and the combination of fundamental practical and scientific research theory training. Third, encourage Mr. to participate in scientific research theory training and all kinds of science and technology competitions. Cultivate diversified use-type talents, in order to cultivate use-type, complex, skill-oriented talents, strengthen the graduates' unemployment ability, and complete the expected purpose of this course. Fourth, electrodynamics is also a highly theoretical course, the object of its study is distinguished from the physical shape of matter, with generalized characteristics. In order to prevent the mathematization of the course teaching, we will make full use of the advantages of contemporary information technology, such as video teaching materials to strengthen Mr. rational view and the ability to start. Again, the experimental class and theoretical training should pay attention to cultivate Mr. logical thinking, inventive thinking ability and quality, and fully develop Mr. physical thinking and physical exploration ability.

Fourth, the course teaching methods to explore

The course teaching should pay attention to the combination of electrodynamics practice and theory, respect for the subjectivity of Mr. Learning, the appropriate arrangement of guided self-study, to cultivate Mr. Self-study skills. Enhance the Mr. before class, after class Q&A counseling, focusing on the cultivation of Mr. talent, so that Mr. electrodynamics through the understanding of the fundamental reality of electrodynamics, view and master the principle of electrodynamics seminar law, open up the mind, initially cultivate Mr. scientific research ideas.

1.? Bilateral reaction type? Teaching method

This teaching method consists of? Self-study? and? Reaction? Two parts of the composition, its focus is on Mr. in the instructor under the guidance of self-study and the instructor by the reaction to the information to stop the focus of the explanation, so that Mr. talent in the repetition of the training lost in the refining. Self-learning? and? reaction? Performance of Mr. and the instructor's mutual contact, mutual cooperation, mutual role in the training process.

2. Achievement-centered, classroom discussion

teaching methodology suggests that classroom teaching in accordance with the superstition, subjectivity, development of the quasi-criteria, the use of Mr. as the main body of the group discussion-based approach, from the results of the start, to stimulate Mr. Learning interest, so that Mr. Targeted to explore and use of actual knowledge of the practical achievements; can also be designed for the scientific research task of the department of science and research The results encountered in the design of the discussion or consideration of the problem, in order to inspire Mr. analysis, discussion of electrodynamics results, learning and solid electrodynamics knowledge, open up the mind, cultivate scientific research ideas.

3. Advocating the learning-guided teaching method

Under the guidance of the instructor, Mr. stop self-study, self-practice, the instructor of Mr. cognitive activity in the teaching process as the main teaching activities, so that Mr. automatically to obtain knowledge, the development of their respective capabilities, so as to achieve in the full development of Mr. automaticity on the basis of the infiltration of the correct guidance of the instructor, so that the teaching of the single-party to make the best use of their abilities, each of which has its own advantages and disadvantages. The first time I saw this, I was able to see it in the back of my head.

4. More extracurricular theoretical activities

Extracurricular theoretical training, pay attention to the cultivation of Mr. logical thinking, inventive thinking ability and quality. Encourage and instruct the talented Mr. into the scientific research theory training, participate in all kinds of science and technology competitions. Mr. written course essay into the teaching process, from which the quality of the project into the scientific research theory training. Fully apply the physics, electronic competitions and other innovative platforms to promote the teaching of electrodynamics courses, cultivate the use of type, complex, skilled personnel, and strengthen the graduates' ability to unemployment. Electrodynamics? As an exploratory course, in the classroom teaching, to highlight the participation of Mr., so that they automatically obtain rather than actively bear the conclusions of the superstition, interactive ideas so that Mr. feel electrodynamics contemplative, not difficult to get started. Electrodynamics? and other branches of physics have? individuality? and? Characteristics The relationship between the two. In order to stimulate the interest of Mr. learning, you can often use the classroom discussion method, by Mr. asked questions, under the guidance of the instructor to discuss, summarize the correct conclusions. Since the analysis of? Electrodynamics need to use general ideas, so the classroom teaching should make full use of multimedia, try to use images and color matching, so that the gentleman to establish the correct physical image. Pay attention to Information Technology and? Electrodynamics Effective integration of the course, which on the whole optimization of the teaching process, improve the professional knowledge of Mr. learning effect, improve Mr. information technology skills, cultivate Mr. collaborative understanding and innovation are of serious ideal significance. At the same time, the teaching practice can be used in the training of innovative theoretical ability, used in physics, electronics and other types of competition.

References:

[1]Feng Yunguang. Exploration of the change of electrodynamics teaching in physics majors [J]. Talent, 2014,(19).

[2]Zheng Wei, Lv Yan. Discussion on the establishment of network teaching platform of electrodynamics[J]. Journal of Shenyang Normal University (Natural Superstition Edition), 2013, 31(4): 531-534.

[3]Liu Jia. Discussion on the innovation of course system of Electromagnetics and Electrodynamics [J]. Science and Technology Information, 2013,(11):44.

[4]Xiong Wanjie, Lu Jianlong. A study of ? Electrodynamics? An investigation of curriculum change [J]. Elementary Liberal Arts Education, 2003,(6):72-75.

[5]Fu Changbao, Xu Guohui, Wang Xiying. Discussion on learning approach based on electrodynamics teaching change [J]. Journal of Tonghua Teachers College, 2009, 30

Physics thesis article 2

Try to talk about the power information physics fusion system

Abstract The rapid development of embedded systems, computer technology, network communication technology makes it possible to build the future smart grid, based on the information physics system (CPS) technology to build the power information physics fusion system (CPPS) for the realization of future The construction of power information-physical fusion system (CPPS) based on information-physical system (CPS) technology provides new ideas for realizing future smart grid. In this paper, a preliminary study and analysis of the CPPS platform is carried out, and the synchronous PMU technology, open communication network, and distributed control applied in CPPS are introduced.

Keywords CPPS; synchronous PMU; open communication; distributed control

Introduction

Driven by the energy crisis, environmental protection pressures, as well as the continuous improvement of the user's requirements on the quality of power (QoS), the contemporary power system no longer meets the needs of the development of the society, the smart grid has become the direction of the development of the future power system. Smart Grid has become the future direction of power system development. The main reasons for the development of Smart Grid are as follows:

1) Distributed Generation (DG) access to a large number of power grids lead to system stability problems. Due to the large number of DG access to the grid into a fault current and operating power flow in both directions of the active network, increasing the complexity and vulnerability of the system, so there is an urgent need to develop a smart grid to solve the DG large number of access to the grid caused by the system stability problems.

2) The increasing power quality (QoS) requirements of power users. Modern society a short period of power outages can also bring huge economic losses to high-tech industries, in recent years, the occurrence of major power outages is the society has brought incalculable economic losses. Therefore, there is an urgent need to establish a strong and self-healing smart grid to provide high-quality power services.

The main structure of the paper is as follows: Part 1 introduces the development of Cyber Physical System (CPS) technology in recent years, and the interrelationship between CPS and Smart Grid; Part 2 introduces the hardware platform model of Cyber-Physical Power System (CPPS); Part 3 introduces the hardware platform model of CPPS; Part 4 introduces the hardware platform model of Cyber-Physical System (CPPS); Part 5 introduces the hardware platform model of CPPS; and Part 6 introduces the hardware platform model of CPPS. hardware platform model; Part 3 introduces the synchronous Phasor Measurement Units (PMU) technology; Part 4 provides a preliminary analysis of the open communication network in the CPPS; Part 5 provides a brief introduction to the distributed control technology of the CPPS; and finally Part 6 summarizes the full text.

1 Interrelationship between CPS and Smart Grid

The development of CPS technology has benefited from the rapid development of embedded system technology, computer technology and network communication technology in recent years, and its ultimate goal is to realize the control of the physical world at any time and any place.

CPS realizes the environmental perception of the physical world by embedding a huge number of wireless sensors with a wide range, and realizes the control of the physical world through a high-performance, open communication network. CPS realizes the environment perception of the physical world by embedding a huge number and variety of wireless sensors, realizes the safe, timely and reliable communication within the system by means of a high-performance and open communication network, and realizes the goal of autonomous coordination and remote precise control by means of a high-precision and reliable data processing system [1].

CPS technology has been initially studied and applied in the fields of warehousing and logistics, autonomous navigation vehicles, unmanned aircraft, intelligent transportation management, intelligent buildings, and smart grids [2].

Introducing CPS technology into smart grid, the concept of Cyber-Physical Power System (CPPS) can be obtained. In order to analyze the interrelationship between CPPS and smart grid, the concept of smart grid is first briefly reviewed. At present, there are many concepts about smart grid, and no unanimous conclusion has been reached. Martin Hauske, a senior power expert of IBM China, believes that smart grid has three levels of meaning: firstly, it utilizes sensors to monitor in real time the operating conditions of key equipment in power generation, transmission, distribution, and power supply; then, it transmits, collects, and integrates the acquired data through network systems; finally, it analyzes and mines the real-time data to make sure that the data is not lost in the process of power generation. Through the analysis of real-time data, mining, to achieve the purpose of optimizing the management of the entire power system operation [3-4].

From the introduction of CPS and smart grid above, it can be seen that CPS and smart grid are conceptually similar, and they both emphasize the use of cutting-edge communication technology and high-end control technology to enhance the ability to perceive and control the environment of the system. Therefore, the CPPS established on the basis of CPS provides a new way of thinking and realization for promoting the deep integration of the primary system of electric power and electric power information system, and ultimately realizing the construction of a complete smart grid.

2 Hardware platform architecture of CPPS

Based on the system stability problem caused by the extensive access of distributed energy to the power grid and the overall goal of establishing a strong and self-healing smart grid, the establishment of a safe, stable, and reliable smart grid has become an important direction for the future study of power systems, and is also the main content of CPPS research.

Traditional power system monitoring methods mainly include SCADA/EMS system based on power system steady state monitoring and various fault recorders focusing on electromagnetic transient process monitoring, and protection control methods mainly include centralized control methods based on SCADA master station and local control methods based on the installation of protection control devices [5]. The local control method is easy to realize and has a fast response speed, but due to the limited use of information, the control performance is not perfect enough to predict and solve the unknown faults of the system, and it is not able to act accurately for the multiple response faults of the power system. Centralized control mode using the system global information, can optimize the system control performance, but the calculation of data is huge, communication links, the system response speed is slow, and the existing SCADA system is mainly on the power system for the steady-state analysis, can not be effective control of the dynamic operation of the power system.

For the current power system monitoring, control means of the inadequacy of the future smart grid to establish a strong self-healing, must establish the corresponding wide-area protection of real-time dynamic monitoring system, CPPS hardware platform is based on the establishment of up.

CPPS hardware platform 6-layer architecture shown in Figure 1, including: physical layer (power primary equipment), sensing drive layer (synchronous PMU), distributed control layer (intelligent terminal unit STU, intelligent electronic device IEDs, etc.), process control layer (control sub-station PLC), advanced optimization and control layer (SCADA master control center) and the information layer (open). Communication network).

Among them, the underlying physical layer refers to the primary equipment of the power system, such as power plants, transmission and distribution networks. The process control layer mainly refers to the control sub-stations of the hub power plants and substations, which is an important part of the CPPS, and establishes the control loop at the system level by collecting the data information from multiple measurement nodes and makes the corresponding control decisions. The advanced optimization and control layer is the dispatch center control master station, which mainly provides manually assisted optimization and control for the dynamic operation of the power system. The top information layer is the open communication network of the smart grid, note that the information layer is not a separate layer, but overlaps the various sub-layers of the CPPS, providing secure, timely and reliable communication for the components within the CPPS.

The hardware platform model of CPPS is given above, but to specifically implement CPPS in the power system involves many aspects of the technical difficulties, the following synchronous PMU, open communication network, and distributed control in CPPS are briefly introduced.

3 Synchronous PMU measurement technology

Synchronous PMU is the basis for building CPPS, which provides rich measurement data for dynamic monitoring of wide-area protection in CPPS. The synchronous PMU device mainly measures and outputs synchronous phase quantities within the power system, and the installation points include large power plants, contact line drop points, important load connection points, and control systems such as HVDC, SVC, etc. The measured data include three-phase voltage, three-phase current, switching quantity of the line, and three-phase voltage, three-phase current, switching quantity, excitation current, excitation voltage, excitation signal, valve opening signal, AGC, AGC, and SVC of generator. opening signal, AGC, AVC, PSS and other control signals [6]. The measured data can be used to analyze the stability margin of the system and provide a basis for dynamic control of the power system.

The block diagram of the hardware structure of the synchronous PMU is shown in Figure 2.

Among them, the GPS receiver module will be within the accuracy of ?1 microseconds of the second pulse to the time pulse and the standard time signal into the A/D converter and the CPU unit, as the standard time source for data acquisition and vector calculation. The three-phase currents and voltages measured by the voltage and current transformers are filtered and shaped and A/D converted, and then sent to the CPU unit for discrete Fourier calculation to find out the synchronized phase quantities before output. Note that the generator PMU in addition to the measurement of terminal voltage, current and excitation voltage, current, but also need to access the key-phase pulse signal to measure the generator power angle [7].

4 CPPS open communication network

The establishment of CPPS open communication network, should be based on ensuring safe, timely and reliable communication, so that the system has a high degree of openness, to support the automation equipment and application software plug and play, to support the combination of distributed control and centralized control. For the establishment of an open communication network, communication real-time analysis, network security and reliability analysis is required.

4.1 Application of IEC 61850 standard

IEC 61850 standard as a new generation of network communication standards used in intelligent substations, support for plug-and-play and interoperability of equipment, so that the intelligent substation has a high degree of openness. power grid communication standard [8], therefore, using IEC 61850 as the communication standard for CPPS communication network is the best choice.

The core technologies of IEC 61850 [9] include object-oriented modeling technology, XML (Extensible Markup Language) technology, software reuse technology, embedded operating system technology, and high-speed Ethernet technology.

4.2 Communication Network Configuration and Analysis

For the network configuration of the CPPS open communication network, reference can be made to the three-layer, two-network network structure configuration of the intelligent substation, and the 3-layer communication network of CPPS can be constructed, as shown in Figure 3.

Among them, the bottom layer is a large number of PMUs, STUs/IEDs located at power plants, substations and important loads, which are responsible for collecting real-time information and executing protection and control functions, respectively. The middle layer is the control sub-station (process control unit PLC), and each control sub-station is connected with multiple PMUs, STUs/IEDs to complete the protection control at the system level of the partition and upload the data to the SCADA master control center as needed.The SCADA master control center receives the uploaded data from each control sub-station and sends the control information to each control sub-station after processing to realize the wide-area protection control function of CPPS. Wide-area protection control function of CPPS. Note that each layer of equipment is embedded with GPS to achieve accurate timing and ensure system-wide synchronized data sampling.

5 Distributed control mechanism of CPPS

To establish a strong and self-healing smart grid, it is necessary to utilize a new type of control mechanism to establish a reliable power control system. According to the path and scope of power fault expansion and the time evolution process of faults, the establishment of a spatio-temporal coordinated defense framework for major power outages is proposed in the literature [10-11], which establishes the 3 lines of defense of the power system, and lays a good foundation for the realization of the wide-area dynamic protection and control of the smart grid.

Distributed Control (DC) of the power system is relative to the traditional SCADA master centralized control method, referring to the multi-computer system, i.e., with multiple computers (refers to the embedded system, including PLC control sub-station and STU/IED, etc.), respectively, to control different devices and objects (e.g., generators, load, protection devices, etc.), each constituting an independent subsystem, and the subsystems are interconnected through a communication network to accomplish the overall control objectives of the system through mutual coordination and assignment of tasks [12]. The core feature of distributed control is ? Decentralized control, centralized management? On the basis of the 3 lines of defense of the power system, combined with distributed control technology, the 3-layer control architecture of CPPS is established, as shown in Figure 4.

Among them, the distributed control layer is mainly the control measures taken at the beginning of the fault (slow on-off stage), and its control goal should be to ensure the stability of the system under less serious faults and prevent the spread of faults. The process control layer is a wide-area emergency control measure taken when a serious failure has already occurred in the system (cascading collapse start phase), which requires a larger cost. Typically for specific faults that may destabilize the system, it is often necessary to cast off non-faulty equipment to ensure system stability. Wide-area emergency control measures should be implemented as soon as the fault is recognized; the later the control measures are implemented, the less effective the control will be. The optimization control layer is the control measure taken after the first two control layers have all refused or under-control without achieving the control effect, and at the same time, after various instabilities have been detected, which usually requires multiple rounds of load-shedding and oscillatory de-listing. In the power restoration phase, there should be adaptive black start and self-healing control scheme.

6 Conclusion

Introducing the CPS method into the power system and establishing the modeling platform of CPPS provide new ideas for establishing a strong and self-healing smart grid. The synchronized PMU measurement technology, open communication network technology, and distributed control technology in CPPS are briefly introduced in the paper.

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