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Abstract

Introduction

      Electricity in industrial production is used in the electric drive, a variety of electrical technology and lighting installations. Accordingly, the parameters of electricity required for its effective use in specific cases should be different. Often, the frequency of the alternating voltage, its value requires changes directly during the process. At the same time, electricity sources - power systems, transformer substations provide consumers with standard electricity in the form of three-phase alternating current with a frequency of 50 Hz and a number of standard voltages from 0.4 to 220 kV. To meet the needs of production in electricity of various types and parameters, as well as for the effective management of its distribution, various conversion devices are needed. Voltage-current converters (PNT) are also an important element in the circuitry of analog electronic devices. On their basis, various precision operational amplifiers can be performed in which PNT is used as an input differential stage; PNT organically included in the structure of the ALP and can be used in various measuring circuits.

1. Theme urgency

Direct current is used in transport, in electrochemistry, in electric drives, etc. This type of electrical energy consumption is 25% of the power consumed by alternating current.

In technology, there is always a need for smooth control of the speed of rotation of mechanical devices or changes in power consumption:

- regulation of lighting in rooms

- variation of the speed of rotation of sewing machines,

- software change the speed of rotation of metalworking centers, etc.

Rectifiers are designed to power electrical devices whose principle of operation is based on the use of direct current sources. Such devices include all radio communication devices for industrial and domestic purposes, power supply of autonomous mobile mechanisms, industrial electroplating plants, electroforming, electrolysis, and much more.

In addition to rectifiers, there is currently a large class of inverters that convert a current source into a variable frequency current. Although this problem was previously related to the accumulation of energy from the AC network to the DC energy storage source, and during peak hours, this energy is pumped to the AC network. Such devices are called the inverter slave network.

The use of semiconductor devices allowed:

- to reduce the weight of the transducers by 3..7 times (this made it possible to do without lifting devices for moving or installing transducers),

- increase the efficiency by an average of 10..40%;

- abandon complex water or oil cooling valves;

- get great energy savings.

Since the introduction of power semiconductors in the control system of pumps and compressors gave energy savings of 30%, in transport 20..30%, in drives of industries that produce paper, 14%, etc. Semiconductor power technology allowed:

- create inertia-free converters,

- increased the durability of devices several times,

- increased the reliability of installations,

- allowed to create converters for an unusually wide range of power converters. So in home appliances converters have a capacity of 100 watts, and in industry up to several megawatts.

Currently, semiconductor converters serve:

- household appliances,

- public service equipment,

- pump stations of water supply and power plants,

- grain processing mills,

- cement plants, electric transport,

- textile industry, metal rolling centers, where power is consumed from 20 to 40 MW (about 3000 electric motors),

- reduce the cost of the converter in comparison with converters on mercury valves.

This allows us to conclude that the semiconductor technology has a future.

2. Goal and tasks of the research

The purpose of the study is a comparative analysis of various types of direct frequency converters with a DC link.
- Consider various power circuits of the inverter with a DC link.
-To conduct a simulation of transients in blood pressure when powered by various inverters
-Carry out a comparative analysis of the results obtained when the blood pressure from the NFC and the inverter with a DC link
- Consider the theoretical issues of construction and range of use of the NFC.
-Develop a mathematical model of the power of blood pressure from NPC
-To consider the option of supplying blood pressure from a matrix frequency converter

3. Review of research and development

Practical studies have shown that the slightest power failure leads to the failure of sensitive equipment of the vessel traffic control system (VTS), shortens the service life of the equipment, can lead to loss of information, and lead to an emergency situation in the port water area. The power supply of the VTS Centers of the first and highest category is provided by a special group of the first category of reliability, which includes: two industrial power lines with automatic backup; backup diesel generator with automatic input reserve; autonomous uninterruptible power supply. Power supply of objects of VTS is carried out with the help of: industrial power supply line; backup diesel generator with automatic input reserve; autonomous uninterruptible power supply. Therefore, the problem of the quality of electrical energy is important and relevant not only in the field of energy, but also in systems of centralized and autonomous power supply of VTS.

Conclusion

- The developed mathematical models will be used in the laboratory workshop for the courses: "Electronics" and "Elements of an automated electric drive."
-The results of simulation of the inverter with a DC link, showed that when using an inverter with PWM on IGBT transistors in the form of current, a significant amplitude of the 3rd harmonic appears compared to a 2-level inverter with PWM.
-NPC studies have shown their capabilities as an energy source for an AC motor.
- Theoretically, the questions considered in the work will be used when reading the courses: "Electronics" and "Elements of an automated electric drive."

References

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