RU2719549C1 - Two-phase-six-phase transformer with rotating magnetic field - Google Patents

Abstract

FIELD: electrical engineering.SUBSTANCE: invention relates to electrical engineering and can be used as a voltage converter for powering industrial plants, electrical devices and various processing systems. Two-phase-six-phase transformer with rotating magnetic field comprises six-phase secondary winding and two phase windings wound on toroidal core, shifted in space by 90°. At that, the first primary winding is connected to the output of the first bridge single-phase voltage inverter, the second primary winding is connected to the output of the second single-phase bridge voltage inverter. First and second voltage inverters are made with pulse-width modulation, their output voltages are shifted in phase relative to each other by 90°, and their inputs are combined and connected to a source of constant voltage.EFFECT: obtaining a multiphase voltage system from single-phase supply voltage with improved power indices and expanded functional capabilities.1 cl, 2 dwg

Description

The invention relates to the field of electrical engineering, in particular, converter technology and can be used in electric drive and power supply systems.

Known two-phase-six-phase transformer with a rotating magnetic field (patent RU 2333562, IPC H01F 30/14, published on 09/10/2008 in Bull. No. 25), which can be taken as a close analogue on the basis of the formation of a circular magnetic field using a two-phase voltage system. It contains four primary windings located on the toroidal core, a ballast resistor and inductance, and multiphase secondary windings. To obtain a rotating magnetic field, the first, second and third, fourth windings are located relative to each other on a toroidal magnetic core with a shift of 90 °. The number of turns of the first and fourth windings is twice more than the second and third.

The disadvantage of this transformer is its low energy performance, due to the asymmetrical design of the primary windings.

The prototype is a two-phase-six-phase transformer with a rotating magnetic field (patent RU 191500, IPC: H01F 38/18, H01F 30/14, publ. 08.08.2019 in Bull. No. 22). It contains a six-phase secondary winding and two phase primary windings wound on a toroidal core, shifted in space by 90 °. Moreover, each phase primary winding contains two semi-windings included in the opposite direction. The primary half-windings are connected to a constant voltage source by means of fully controllable switches, the switching of which between the two primary windings is carried out with a phase shift of 90 ° and through 180 ° between the half-windings of each primary winding.

The disadvantages of the prototype, first of all, include large distortion of the currents in the primary windings of the transformer and low energy indicators in this regard. In addition, the prototype device has limited functionality associated with the inability to regulate the voltage when it is connected to an unregulated power source.

The objective of the technical solution is to increase energy performance and expand functionality.

The technical result from the solution of the problem is to improve the shape of the currents in the primary windings of the transformer, thereby achieving a high quality circular rotating magnetic field and reducing the magnetic and electrical losses of the transformer. In addition, an expansion of functionality is achieved due to the possibility of simultaneously controlling the frequency and the effective voltage value during the conversion of a two-phase voltage system into a six-phase one.

The specified technical result is achieved by the fact that the first and second phase primary windings are connected respectively to the outputs of the first and second single-phase bridge voltage inverters, the inputs of which are combined and connected to a constant voltage source, while both single-phase bridge voltage inverters are made with a 180-degree control algorithm and pulse-width modulation, and their output voltages are phase-shifted relative to each other by 90 °.

The essence of the proposed technical solution is illustrated by the following description and the accompanying graphic material, where in FIG. 1 shows a diagram of a two-phase-six-phase transformer, and in FIG. 2 oscillograms of currents and voltages at the two-phase input of the transformer.

In FIG. 1, the following designations are introduced: 1, 2 - the first and second single-phase bridge voltage inverters, 3, 4 - clamps of a constant voltage source, 5, 6, 7, 8 - keys of the first inverter, 9, 10, 11, 12 - keys of the second inverter, 13, 14 - the first and second primary windings, 15 - the toroidal core of the magnetic circuit, 16 - 21 - phase secondary windings of the transformer. In FIG. 2 shows a timing diagram of the control pulses of IGBT modules (fully controllable transistor modules), where U _y1 , U _y2 are control signals supplied to the keys of the first and second inverters, respectively. In this case, the open state of the keys 5, 6 of the first inverter provides a positive voltage pulse in the winding 13, and the open state of the keys 5, 7 - the absence of voltage in this winding. The open state of the keys 7, 8 ensures the presence of a negative voltage pulse in the winding 13, the open state of the keys 8, 6 - the absence of voltage in the same winding. The keys 9, 10, 11, 12 work similarly to the keys of the second inverter 5, 6, 7, 8, respectively, but with a temporary phase shift of 90 °.

The elements of the device are connected as follows.

Clips 3 and 4 of the transformer are connected to a constant voltage source. Next, terminal 3 is connected to the left inputs of the first and second inverters, terminal 4 is connected to the right inputs of the first and second inverters. The coil of the first primary winding 13 is connected to the output of the first single-phase bridge voltage inverter, the coil of the second primary winding 14 is connected to the output of the second single-phase bridge voltage inverter.

Two-phase-six-phase transformer with a rotating magnetic field operates as follows. Through the control of the keys of the first inverter, direct current pulses are applied to the first primary winding, which form a current close to sinusoidal, shifted by a certain angle relative to the applied voltage. To the second primary winding with a shift of 90 °, relative to the moment of supplying pulses to the first primary winding, DC voltage pulses are applied, which form a current close to sinusoidal, shifted 90 ° relative to the current on the first primary winding. Thus, a rotating magnetic field is formed in the core of the magnetic circuit, which induces a multiphase current in the secondary winding system.

The novelty of the claimed technical solution lies in the fact that increased energy performance and expanded functionality.

The invention can be used as secondary power sources in power supply systems and electric drives.

Claims (1)

A two-phase six-phase transformer with a rotating magnetic field, containing a six-phase secondary winding and two phase primary windings that are wound on a toroidal core with a spatial shift of 90 °, characterized in that the first and second phase primary windings are connected respectively to the outputs of the first and second single-phase bridge inverters voltage, the inputs of which are combined and connected to a constant voltage source, while both single-phase bridge voltage inverters are made with a 180-degree algorithm ohm control and pulse width modulation, and their output voltages are phase shifted relative to each other by 90 °.

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