Prospects for the development of an automated electric drive

The specifics of the development of modern civilization, especially in the last ten years, cardinally changes our lives. Two trends deserve the most attention.

The first is the rapid development of everything related to computer technology. This is not only a computer in every home and workplace, not only the Internet and “toys”. If you look more closely, then we have all been hostages of computer technology for a long time. Almost any device now has a control chip in its composition, which, in principle, is the same small computer. This is a TV, and a washing machine, and a mobile phone, and a camera, and a keychain to the car, and the car itself ...

Now in my office at work about 60! CPU control ... This is already very serious! If the microprocessor used to cost tens and hundreds of dollars, now you can buy a control chip for less than a dollar!

The second trend is an increase in the cost of energy, and everything related to the mining industry. All resources have risen in price over ten years. So in 1998 we bought 1 liter of 95th gasoline for 2 rubles 15 kopecks, and now we pay almost 22 rubles (the article was written at the beginning of 2008), and now nobody counts a penny again ... As before the denomination ...

This is all of direct relevance to an automated electric drive, which is integrated into our lives and is the basis of production. Now it is simply economically feasible to make any electric drive automated, that is, computerized. This is not a tribute to time, with an irresistible desire to shove into all microprocessor. The most important thing is to make it able to significantly save energy. Automation, with this approach, pays off in a year, and sometimes faster.

In addition to this, an automated electric drive has a number of significant advantages:

- improved consumer qualities (compare at least a modern washing machine with the one that you had twenty years ago);

- regulation of speed, acceleration and braking intensities, allows you to simplify, that is, reduce the cost of the mechanical part, set sparing modes for all mechanics, reduce starting and operating currents, extend the life of the mechanical and electrical parts;

- the possibility and feasibility of making a distributed drive control system; - integration of electric drives into the network with a data collection and analysis server with the possibility of remote access.

Now let's analyze the current situation with the electric drive. It is largely determined by historical conditions. Currently, the electric drive is being built with the separation of the electric power converter and the control system into high-current and low-current parts. Currently, the control system most often refers to a digital controller. The first in this bunch appeared electric cars. The preparation for their creation was the whole history of electricity. It turned out that the controlling industrial controller was “attached” to the converter-motor (P-D) system (see Fig. 1).

If the mechanism has several drives, then another industrial controller appears ... This approach has several disadvantages:

- high cost of the system;

- feedbacks “passed” through the industrial controller give significant time delays;

- an attempt to reduce the price of the product leads to "motley" automation, with a difference in interfaces and an increase in time delay; It often happens like this: a mechanism that had an unregulated drive is complemented by an adjustable one, it's easier ...

For example, the coordination of the mechanisms of a line is done the old fashioned way, through mechanics. It turns out a very expensive and very "tricky" unit with an abundance of interfaces, which leads to additional costs for commissioning. And if a failure (breakdown) occurs in such a system, then there will be even more problems. The integration of such systems for general monitoring is a very difficult task. All this can be compared with the combination of computers from different manufacturers in a working group, with different speeds, with various network interfaces and various network standards.

Now back to the prospects of an automated electric drive. The main thesis is the creation of a distributed control system, with minimizing prices and a simple and understandable way to integrate these drives into a common network.

Everything resembles the development of personal computers. Any modern frequency converter has a processor. Why do I need an additional industrial controller? These are costs, an increase in the response time of the system, and a deterioration in reliability. And just the inverters of modern manufacturers are made as a "black box", and they perform the only task - to convert the input signal to the appropriate frequency and voltage. Convir offers alternatives. We do not set the industrial controller. The necessary feedbacks are made in the inverter. The inverter also has a control program for solving all technological problems. The inverter has a built-in CAN-open interface for integrating such a node into the network (see. Fig. 2).

In principle, such a node can work independently, the network serves to enter the settings and collect information about the work. Thus we get a single-processor control system with maximum speed, reliability and minimum price! To combine the drives and coordinate their work, it remains only to connect them via CAN - bus "twisted pair". If you need remote monitoring and logging of the mechanism, then we put an additional industrial server with SQL database and ethernet interface. Combining the nodes of distributed electric drives in a network is free!

Now we will consider in detail the advantages of such a system. We have a number of automated electric drives with a distributed control system, which are networked. Each individual drive is virtually independent and can work even if the network is disconnected. Since the number of connections at the drive is minimal and the processor has instant access to all parameters of the node, we have maximum speed, flexibility and reliability! The network is coordinating the operation of electric drives. If we are dealing with an automated line or simply a multi-drive mechanism, then the mechanical part can be greatly simplified and cheapened by automating the operation of coordinated drives.

Any CAN panel or computer can be used to control the system. These devices do not perform control tasks, but serve solely for input-output. If we put a computer, we also get the opportunity to log work. The system is built as friendly as possible for communication with any program controlling the work of production, for example, 1C. Since the electric drive in such a system is, indeed, automated, due to this, energy saving algorithms are used to the maximum extent possible. In addition, shock mechanical and electrical loads are limited!

Life does not stand still. Manufacturing technology is developing rapidly. And we must clearly recognize that the cornerstone in these processes is an automated electric drive.