Electrical Engineer Competency Characteristics
1. Can use the computer for plc control programming and debugging.
2. Can use the computer to draw cad electrical principle drawings.
3. According to the requirements of the design of the drawings, the electrician tools can be skillfully used to wiring and installing the electrical circuits of the equipment.
4. According to the requirements of electromechanical system control, on-site programming and debugging can be carried out.
5. Can quickly design solutions according to customer requirements.
Progression Level 1: The Growth Phase
1. Programming software learning: master one or more kinds of plc programming software and products. For example: codesys, cpx-cec, cecx, cecc
2. Electrical CAD drawing software learning: According to the customer's requirements for mechanical and electrical system control, the system electrical schematic is designed according to industry standards. For example: eplan
3, touch screen software programming configuration: high-end human-machine interface to give customers a high-tech feeling. For example: cdpx, design studio
4, electrical control cabinet line installation: to the position of a real electrical engineer, you need to have the first three basic capabilities. When the newcomer first entered the factory, he did not know how to understand the principle of equipment control, plc programming was not skilled, the online check of a component model could not be found, the electrical drawings were also read for most of the month and could not understand, so that there would be a year, or even half a year to change the working environment. Therefore, to engage in the industrial control industry, we must be firm in our choice, "find the right way, give the right medicine", and take advantage of the youth to be cruel to yourself.
5. On-site debugging: analyze the cause of the system failure and troubleshoot the fault. It requires long-term practice accumulation, continuous diligence and love for the industrial control industry.
Advanced Level 2: Ability Breakthrough
1, if you are an electrical engineer in your own company, then as long as you are familiar with the equipment electrical of your own company.
2, if it is to do services to customers, then just familiar with a plc product is not enough. The more skills you master, the more experiences you have, the more experiences you have.
3. If you want to become a senior electrical engineer, you also need to learn hydraulic pneumatic transmission, inverter speed control, servo drive and so on. These can be slowly learned and accumulated in the actual project of work.
Advanced To Level 3: Excellence Stage
1. Proficient in the process
For example, in the boiler control system, the drum level is an important control parameter, which reflects the equilibrium relationship between the boiler load and the feed water. The high level of the steam drum will cause the steam belt water to be unfavorable to the operation of the superheater and affect the separation effect of soda and water; the liquid level is too low will cause the destruction of the boiler water cycle, affect the operation of the economizer, and easily make the water vaporize and burn the boiler or even explode. In addition to the normal factor of heating vaporization, there are also fluctuations in steam load and feedwater flow. When the load suddenly increases and the pressure of the steam drum suddenly decreases, the water will vaporize sharply, and a large number of bubbles will appear, forming a "false liquid level". To this end, in the design of the control scheme, the three-impulse control of liquid level, steam and feed water is often adopted. If you do not understand the process, using a simple level control system, once a "false level" occurs, it will affect production and even cause danger. Therefore, automation engineers must work the process and be proficient in the process.
2. Choose the right network
For an automation project (especially for medium and large-scale control systems), the choice of network is very important, and even some people have proposed the concept of "network is the controller", so it is necessary to be familiar with various industrial buses and Ethernet protocols. First of all, the network must be open to facilitate the integration of different devices and the expansion of future system scale; secondly, the form of the network is selected for the transmission performance requirements of different network levels, which must be carried out under the premise of a deeper understanding of the protocol and mechanism of the network standard; in addition, the specific issues such as system cost, equipment compatibility, and field environment applicability are comprehensively considered to determine the network standards used at different levels. The performance of a real-time system can be measured in terms of time, reliability, and application object.
3. Master the principle of plc scanning
Compared with other control devices, the most important feature of plc is "scanning". After the plc is powered on, the program scan and I/O scan are automatically repeated, that is, the input sampling, user program execution and output refresh are three stages. Completing the above three phases is called a scan cycle. In the input sampling stage, plc reads all the input states and data in turn in a scanning manner, and stores them in the corresponding units in the I/O image area, after the input sampling is completed, it is transferred to the user program execution and output refresh stage, even if the input state and data change, the state and data of the corresponding units in the I/O image area will not change. In the user program execution stage, plc scans the program (ladder diagram) sequentially in order from top to bottom, first left and then right, and refreshes the state of the corresponding unit of the ram storage area or I/O image area according to the results of the logical operation. In the output refresh stage, according to the corresponding state and data in the I/O image area, all the output latch circuits are refreshed, and then the corresponding peripherals are driven by the output circuit, at this time, the real output of the plc. It can be seen that the process and result of the plc program control are different from the relay logic loop, especially when it comes to the order of the steps, the capture of the pulse signal, etc., and the scanning principle of the plc is closely related. In practice, a large number of procedural problems stem from this, and often have incredible results. Therefore, to design a plc program, it is necessary to be proficient in the basic principles of plc.
4. Strive for structured programming
It is the goal of every programmer to comprehensively improve the quality of the program, improve the efficiency of programming, and make the program have good readability, reliability, maintainability and good structure. IEC61131-3 is a standardized programming language for industrial control introduced by the International Electrotechnical Commission (IEC) in 1999, with openness, portability, structured programming and structured data, error detection and error correction capabilities, etc., suitable for plc programming. Structured programming facilitates the construction of programs (especially complex programs), multi-person design, debugging, and software management. While the idea of software engineering has been embraced by the vast majority of programmers, it is not easy to translate this idea into conscious behavior in the software development process.
5. Pay attention to anti-interference measures
Automation systems are used in harsh industrial sites, and anti-interference measures are particularly important. In practice, there are often cases of debugging failures or even equipment damage due to interference. Interference from automation systems has the following 3 types of sources:
1) Space radiation interference;
2) External lines of the system, including interference introduced by power lines, signal lines, grounding systems, etc.;
3) Electromagnetic radiation and line interference inside the system.
In response to these disturbances, the following measures should be considered in the implementation of the project:
1) In the system structure design and equipment selection, fully consider the environmental adaptability and electromagnetic compatibility;
2) Adopt power supply with excellent performance to suppress the interference introduced by the power grid;
3) Reasonable selection and laying of cables and wires;
4) Adopt isolation device or filter device on the hardware;
5) Take measures to improve reliability on the software, such as digital filtering, timing correction of reference point potential, information redundancy, etc.;
6) Correctly select the grounding method, generally using one-point grounding and series one-point grounding.
The article is original for "eplanp8 network" and is transferred from http://www.eplanp8.com/4055.html
[Here David says electrical, David is me I am David, 2018.8.5]