Frequency converters from Delta Electronics
The mechanisms used to control various types of equipment cover only a certain limited scale in the work process, and their operating scheme is quite complex. However, a frequency converter can help eliminate these unpleasant aspects.
Today, some of the best are Delta Electronics frequency converters, which are easy to use, relatively inexpensive, and find application in many fields. They not only save electricity but also ensure safe operation of electromechanical devices – for example, the operation of elevator motors, pumps, compressors, machine tools, and much more.
The operating principle of frequency converters is as follows: using an electric current generated in the stator winding, a moving magnetic field arises, which attracts the rotor cylinder. The rotation frequency of the field is determined as follows: the current frequency (equal to 50 hertz) is multiplied by 60 and divided by the number of pole pairs of the stator winding. Since an asynchronous motor can regulate the frequency of the incoming current, it allows for smooth and steady rotor rotation.
Induction frequency converters have not become particularly popular because they do not have sufficiently high performance indicators. Electronic converters surpass them in all respects, so they are more popular. Their mechanism consists of a rectifier operating from special diode devices, a large filter, an inverter functioning via special power switches and a bridge circuit, and a control system driven by microprocessors. From the converter, an electric current of the optimal frequency for operation is transmitted to the motor winding.
To regulate the rotation speed of mechanisms that do not significantly change load during operation – such as pumps – a scalar control method is used, which allows regulating the operation of several devices connected to one conveyor line.
The amplitude-phase control method is much more widespread, as it provides the necessary rotation speed during sharp changes in the existing load. In addition, such control is less costly due to a significant reduction in energy consumption. The used motor shaft speed sensor, otherwise known as an encoder, greatly simplifies the usage process.
It should be borne in mind that when using a frequency converter, it is necessary to take into account the ratio of the power of the system operating in different modes to the device's ability to withstand certain loads.