I am a fresh graduate, and now I am practicing. I am a property electrician. I want an internship report. Good people help me.

(1) Integrate theory with practice to lay a good foundation for our graduation project.

⑵ Accumulate practical experience, initially master the ability to solve practical problems, and lay a solid foundation for the society.

2. Internship time

March 5, 2007 to March 23, 2007 (* * * three weeks).

3, internship content and requirements

1) internship mobilization. Practice mobilization education and related preparations are mainly to let students know the process arrangement of graduation practice, arrange students to access information online, and prepare for the completion of graduation practice tasks in the later period.

2) Organize lectures. Please ask the engineer of Wuhan Ruipu Power Electronic Equipment Company to introduce the production process of this enterprise. Mainly combine the product development, research and production of the enterprise, so that students can understand the main production process of the enterprise.

3) Arrange students to practice in Rip Power Electronic Equipment Company. Arrange relevant technical engineers to guide students to make power electronic equipment and complete sets of electrical cabinets, so that students can learn and improve in practice.

4) According to the internship experience, consult relevant technical data, make a summary and submit the internship report at the same time.

4. Personal feelings and experiences

In order to enable our graduates to better complete the graduation project, better combine the theory with practice, and provide a certain theme for our upcoming graduation thesis, the School of Information organized our graduates to carry out graduation practice. According to the plan of the college, two groups of graduates from our automation class 036 will conduct a 1 month visit to Rip Company in Qingshan District under the leadership of their tutor Liu Huikang.

On the morning of March 5, 2007, we met at the school gate as scheduled, and then drove to Ripple Company. On the way to Ripple company for half an hour, Mr. Liu arranged our internship requirements and precautions, asking us to take this internship seriously and carefully record the contents explained by the staff, especially the equipment related to our major. We should listen carefully to the staff, study hard after returning to school, and go to the library to find relevant information. And the Rip company is introduced in detail, which makes us have a general understanding of the main products and production capacity of Rip company. After arriving at the company, the master who received us warmly entertained us, but before entering the workshop, he once again explained to us the matters needing attention in the internship, with special emphasis on safety. Under the leadership of teachers and employees, we have a preliminary understanding of the company and equipment.

First of all, we visited the large-scale film-making machine developed by the company under the leadership of Mr. Liu and the staff. The unit is arranged in a horizontal straight line, including an extruder, a 300-screw die, a traction and stretching auxiliary machine, two blowers, two cooling air rings, an air compressor, three winding machines and an electrical control cabinet. The staff introduced us to the parts of the machine and their uses. The unit is equipped with corresponding extruder and auxiliary equipment, which is used to process stretch tapes of blown films of thermoplastics, high pressure polyethylene and polypropylene. Its products can be used in industry and agriculture, as packaging, weaving, ropes and daily civil weaving supplies. , with strong tensile, wear and corrosion resistance. This film-making machine can effectively use the remaining rubber particles in the production process. This kind of equipment is a machine with high output efficiency. According to the staff, in places where there are many electronic enterprises in the south, those by-products can be used in this way. Through the detailed explanation of the film-making machine, we have a preliminary understanding of how electrical control is applied in machinery, and machinery and control are closely related in actual production.

With the practice a few days ago, everyone has some experience in actual electrical production. On the day of 13, Mr. Liu explained the relevant equipment of this major in detail. Roller drilling rig is the main drilling equipment in open pit mine. In order to keep the best speed and strength when drilling ore, it is necessary to adjust with the PLC cabinet of the roller cone drilling rig, so that the roller cone drilling rig can basically keep stepless speed regulation when drilling in different strata, and the PLC cabinet is among them. The machine adopts a unique control model, which makes the rotation speed of drilling tools related to the properties of surrounding rock strata, rotating torque and overshoot of drilling rig vibration. In the workshop of assembling PLC cabinets, it is worth learning that workers are installing lines, dense lines and electrical components for PLC cabinets. The circuit diagram in actual production is more complicated than I expected. For example, this electrical cabinet has three drawings of A 1, and it will take a lot of time to look at the drawings. If installed, it will take more than 1 month. If such complicated work can be completed by automatic production line, it will save a lot of labor time and human resources. This shows that our country still has great potential in industrial automation, and our automation students also have great room for development.

Moreover, it is said by the staff that this machine also adopts double PWM control (pulse width modulation). PWM control is a pulse width modulation technology. By modulating the width of a series of pulses, the required waveform, including shape and amplitude, can be obtained equivalently. The main purpose of PWM control is to achieve good control effect and reduce energy consumption. When the motor runs at a reduced speed, the motor itself will generate a lot of energy. In the past, the equipment was connected in series with a large resistor to consume the energy, but now it can be fed back to the power grid after rectification. Through the introduction of the staff, we know that there is an important conclusion in the sampling control force: when narrow pulses with the same impulse but different shapes are added to the inertia link, the effect is basically the same, and the impulse is the area of the narrow pulse. Basically the same effect means that the output response waveforms of each link are basically the same. This is the principle of reciprocity. Using trapezoidal wave control mode, that is, using trapezoidal wave as modulation signal, can effectively improve the utilization rate of DC voltage.

Double PWM control technology breaks the unified format of the previous frequency converter, and adopts PWM rectifier closed-loop control to eliminate harmonic pollution on the grid side, keep the grid current and voltage basically synchronized, improve the power factor of the whole system, realize the four-quadrant operation of the controlled motor, and make the energy feedback technology have a new development direction.

Today is the last internship. Teacher Liu explained to us a more detailed and professional soft start cabinet. Soft start cabinet is designed and produced by using power electronics technology, microprocessor technology and modern control theory. New starting equipment with international advanced level. This product can effectively limit the starting current of asynchronous motor when starting.

1. Soft start cabinet has the following characteristics:

(1) Reduce the starting current of the motor, reduce the distribution capacity and avoid the investment in capacity increase.

② Reduce the start-up profit and prolong the service life of motors and related equipment.

③ The starting parameters can be adjusted according to the load requirements to achieve the best starting effect.

(4) A variety of start-up modes and protection functions, which are convenient for perfecting the process and protecting equipment.

⑤ Keyboard operation or external control terminal operation can be selected for remote control or automatic control.

⑥ All-digital open keyboard is operated by users, and the operation setting is flexible and convenient.

⑦ Highly integrated INTEL microprocessor control system with reliable performance.

⑧ High-current contactless AC voltage regulating switch with wide voltage regulating range and strong overload capacity. Can be used for frequent start-stop occasions.

2. Technical performance

(1) Soft starting provides stable and stepless electric acceleration, and at the same time reduces the damage to chisel wheel, coupling and belt by reducing torque fluctuation.

② Current limiting starting: By limiting the line impact caused by high impulse current, the efficiency is improved and the starting torque is reduced.

③ Full-voltage start-up: This method will cause current shock, and the slope should be less than 0.1s..

④ Soft shutdown: Its function is to prolong the shutdown time, so as to reduce the load displacement or liquid level overflow during shutdown.

⑤ Pump control: Water hammer caused by uncontrolled acceleration and deceleration of centrifugal pump can be reduced.

⑥ Pulse conflict jump: used for load starting with large starting torque.

3. Protection performance: phase-missing, phase-broken, overload and underload protection.

Due to the above advantages, the soft start cabinet can provide smooth and stepless motor speed regulation, and reduce torque fluctuation, thus reducing the damage to gears, bearings and belts. This type of equipment has been widely used in medicine, South China University of Technology, building materials and industrial and mining fields. It seems that as the saying goes, automation major is a panacea, which is really good. Through several internships, I found that the automation major is intersected by many majors. With the application of many specialties in actual production, automatic control is the only way for industrial development.

Half a month passed quickly. Although the internship was over, we were deeply impressed by what we learned. Although I felt very tired when I went to practice, because I spent most of my time visiting and we didn't know a lot of things, I had to take notes and ask the workers' master, because what we learned at school might have nothing to do with what we actually did. Maybe the school taught a lot of methods to deal with problems or how to analyze them, but when we go outside, it's good not to use them directly, because there are too many majors that we don't know, and then we gradually get familiar with them.

Through this internship, I got to know some new instruments, which are invisible in the school laboratory. Through our careful study and teacher Liu's explanation, we can apply our theoretical knowledge to practice and connect with the instruments in reality, enriching our actual production experience, laying a solid foundation for our graduation design and preparing sufficient materials. Through our internship, we should learn more actively and make up our own shortcomings, because every internship feels that our theoretical knowledge is so limited. In the future, we should use the internet to find some materials, go to the library to find some books, combine what the teacher said with theory, consolidate ourselves, enrich ourselves in the internship, and truly become a qualified college student. This is the ultimate place for our internship.

Moreover, this internship made me understand a truth: "I have a shallow understanding of what I have learned from books, and I have to practice after I know it."

I hope it works for you.