RU128000U1 - TRANSFORMER - Google Patents

Abstract

A w-shaped transformer containing one winding of low voltage, two windings of higher voltage, characterized in that the winding of the lower voltage is located on the central terminal of the transformer, and each of the windings of the higher voltage is located on the corresponding extreme terminal of the transformer, and the higher voltage windings are made in the opposite direction winding.

Description

The utility model relates to the field of electrical engineering and can be used in the most precise experiments in physics, where an adjustable high voltage is needed.

In experiments with neutron beams, the reliable uninterrupted operation of the equipment, which includes a transformer, is of particular importance. Therefore, when solving the task, the task of minimizing all factors that affect the smooth operation of the equipment and interfere with the measuring equipment comes to the fore when developing the elements of the experimental setup.

To create a high voltage, various types of voltage converters are used, which include a transformer. The input of the transformer receives a low alternating or pulsed voltage. An increased alternating or impulse voltage is removed from the windings of the higher voltage of the transformer. For a larger increase in high voltage, the voltage increased on the transformer is supplied to cascade generators of various types. For precision experiments, a Halpern symmetric cascade generator with a low level of pickups is used.

Such a generator requires a certain type of transformer with two windings of the same higher voltage: A. A. Bramyan, B. A. Alterkop, G. D. Kuleshov, Intense electron beams, M., Energoatomizdat, 1984, 232 pp. [1].

It is known that to create the same voltage on the transformer windings, the same magnetic flux and the same number of turns are needed: A.M. Dymkov, V.M. Kibel, Yu.V. Tishenin. Voltage transformers. Moscow. "Energy" [2].

Known U-shaped transformer: S. S. Vdovin, Design of pulse transformers. L., Energoatomizdat, 1991, 208 p., [3].

A lower winding is concentrically located on each rod of this transformer, and a higher voltage winding is wound on it. Such a transformer provides the same magnitude magnetic flux.

But in this U-shaped transformer, the close arrangement of the windings leads to a large amount of stray capacitance of the transformer. This is especially important for high voltage transformers with a large number of turns in high voltage windings. In key voltage converters, the form of voltage on the transistors that are part of the converters is close to rectangular. This leads to large inrush currents of the parasitic capacitance overload (pulsed current through transistors up to 10A) (Questions of radio electronics. Series of general engineering. 1970, N18. L.K.Buevich, VBGaase. Some issues of constructing circuits of high-voltage electron-beam power sources tubes) [4]. This reduces the reliability of operation, increases the level of interference of the voltage converter, the circuit of which (as an external device) includes a transformer.

Known single-phase isolation transformer described in patent RF2199786 [5], containing a three-core magnetic circuit. A secondary winding is mounted on the central shaft. The primary winding is made of two sections mounted on peripheral rods and interconnected with the possibility of the formation in the central rod of magnetic flux in one direction. This transformer stabilizes voltage and is not suitable for high voltage.

Closest to the claimed technical solution for structural features is a W-shaped transformer: Patent WO 2004/040600 [6]. This transformer contains one low voltage winding, which is located on the extreme terminal, two higher voltage windings (secondary windings), which are located: one on the central terminal and the other on the second extreme terminal.

Due to this design, the transformer does not provide the same high voltage on the higher voltage windings due to the fact that the magnetic fluxes in the secondary windings are not the same in magnitude.

Therefore, it cannot be used in installations using symmetrical voltage multipliers (for solving physical problems with increased accuracy).

In addition, there is an air gap in the transformer, which reduces the magnetic flux, and therefore limits the output voltage.

The objective of this technical solution is to ensure the same high voltage on both windings of the higher voltage of the transformer, to reduce the stray capacitance of the transformer and to reduce the level of interference in the equipment, the circuit of which includes a transformer, for example, in voltage converters.

The problem is achieved in that in the well-known W-shaped transformer containing one winding (coil) of low voltage (primary coil), two windings (coils) of high voltage, new is that the low voltage winding is located on the central core of the transformer, and each of the high voltage windings is located on the corresponding extreme terminal of the transformer, and the high voltage windings (coils) are made with the opposite direction of the winding.

The claimed combination of features is not found in open publications.

One of the most rational options for the converter is a resonant converter with switching current or voltage at zero: Power Electronics, N2, 2007. V. Lantsov, S. Eranosyan. Electromagnetic compatibility of switching power supplies, [7]. Such a converter has a high efficiency and low interference level. In such a converter, an oscillatory LC circuit is formed from the leakage inductance and the stray capacitance of the transformer.

In the inventive transformer, the primary winding and the secondary winding are removed from each other by placement on different terminals of the transformer. The symmetrical arrangement of the high voltage windings relative to the low voltage winding provides the same magnetic flux, which is necessary to create the same voltage on both high voltage windings. The same high voltage on both transformer windings is necessary for the Halpern symmetric cascade generator to operate. With such a remote location of the windings of the higher and lower voltage, the stray capacitance of the transformer is significantly reduced. This significantly reduces the inrush current when switching transistors in key circuits. In turn, this leads to a decrease in interference and an increase in the reliability of the converter.

With a remote location of the windings of higher and lower voltage, the transformer inductance increases, which leads to a decrease in the efficiency of the voltage converter. But an increase in the scattering inductance does not have a decisive influence on the efficiency in resonant circuits: V. Lantsov, S. Eranosyan. Quasi-resonant power sources: problems, a new look. Power Electronics, N3, 2007 [8]. The main quantity characterizing the power loss in the resonant circuits is the quality factor of the oscillatory circuit formed by the scattering inductance and stray capacitance of the transformer. In a sequential oscillatory circuit, an increase in inductance leads to an increase in the quality factor of the circuit,

In the proposed transformer, the increase in leakage inductance was compensated for by the small losses of the oscillatory circuit. Using the inventive transformer, an output high voltage was obtained, the same on both high voltage windings (coils) and equal to 10 kV on each winding.

In addition, an increase in the leakage inductance leads to a decrease in the resonance frequency. Decreasing the resonant frequency reduces the magnetization reversal losses of the core material of the transformer and reduces the overvoltage on the transistors. This reduces the likelihood of transistor breakdowns and increases the reliability of the voltage converter,

Known U-shaped transformer [3] makes it possible to obtain the same magnetic flux and the same voltage on both secondary windings. But a converter with such a transformer is less reliable, more energy consuming and has a higher level of interference compared to the proposed transformer.

Figure 1 presents the inventive device in the context, where: 1 - coil (winding) of low voltage; 2, 3 - coils (windings) of higher voltage are made with the opposite direction of winding (left and right winding); 4- the central core of the transformer on which the low voltage coil (winding) is located (1); 5, 6 - lateral rods of the transformer, on which coils (2, 3) of higher voltage are located; 7, 8 - high-voltage conclusions.

Figure 2 (a) shows the waveforms of the current (upper curve) and voltage (lower curve) on a transistor with a P-transformer. Frequency 15.75 kHz.

Figure 2 (b) shows the waveforms of the current (upper curve) and voltage (lower curve) on the transistor with the inventive transformer. Frequency 6.25 kHz.

The operation of the claimed device and the possibility of achieving the effect is as follows.

To the winding of the lowest voltage 1, located on the Central rod - 4 transformers, connect the source of alternating (pulsed) current. Higher voltage windings -2 and 3, located on the side rods -5 and 6, are connected to the load (for example, Halpern symmetric cascade generator). The location of the windings of the higher and lower voltage on different rods of the transformer leads to a decrease in stray capacitance, and accordingly to a decrease in the pulse current overcharging this capacitance, which reduces the likelihood of failure of semiconductor priors and increases the efficiency pre-translator. the location of the lower voltage windings on the central rod, and both higher voltage windings on the extreme ones, creates a symmetric magnetic flux and the same voltage on the higher windings (with equal number of turns).

To reduce the level of interference, it is necessary that the voltage to the Halpern cascade generator is supplied alternately, twice a period. In addition, the high voltage terminal must be on the outside of the winding to ensure electrical safety. In the inventive transformer, in order to comply with these conditions, the higher voltage windings have the opposite winding.

In other words, when the low-voltage leads of the high-voltage coils with the opposite winding are connected, then the voltage at the high-voltage leads (7, 8) of these coils (windings) is equal to the sum of the voltages on each coil.

On the windings of higher voltage 2, 3 receive equal high voltage.

Due to the fact that the high voltage windings are located symmetrically with respect to the low voltage windings, the transformer provides a divided magnetic flux, and the same magnetic fluxes in the coils (windings) of the higher voltage will be symmetrical and the same in magnitude, because the length of the power line connecting the low voltage coil with each higher voltage coil is the same.

Thus, the inventive transformer provides the same high output voltage on the coils of higher voltage, due to their symmetrical arrangement in contrast to the prototype.

The proposed technical solution has the following advantages over the prototype:

1. Provides a symmetrical magnetic connection between the low voltage coil and each high voltage coil, which allows it to be used for precision experiments, where special devices with a low level of pickups and high voltage, such as a Halpern symmetric cascade generator, are used.

2. Ensures the consonant inclusion of 2 higher voltage windings to reduce the amplitude of high voltage ripple and the absence of high voltage breakdowns, as The high voltage leads of the high voltage coils are located on the outside of the coils.

4. The shorter the magnetic field line in the circuit connecting the low voltage coil and each of the higher voltage coils, which reduces the magnetic resistance of the transformer core.

As mentioned above, a U-shaped transformer is known to provide the same high voltage.

When researching a U-shaped transformer, the advantages of the claimed transformer are revealed:

Significantly less parasitic capacitive coupling between the windings, which reduces losses and increases the output voltage. To recharge this capacity requires a large pulsed current. As can be seen from the waveforms of the current (Fig. 2) of the transistor in the lower voltage winding of the claimed transformer, the current has a sinusoidal shape, and in a U-shaped transformer it is strongly distorted (the first half-period has a shape close to rectangular), there is a current surge. When working with the inventive transformer on the current waveform there is no inrush current when the transistor is turned on, which reduces losses and increases the reliability of the converter.

When operating in a resonant power source, due to the increased transformer dissipation inductance (which together with the stray capacitance form an LC circuit), its resonant frequency is significantly reduced. Accordingly, the operating frequency of the resonant converter is significantly reduced, and at the time of closing the key element (transistor), the voltage on it is significantly reduced. This increases the reliability of the converter and reduces energy losses, as it becomes possible to use low voltage transistors with low channel resistance. (figure 2)

The length of the magnetic field line is shorter, which increases the magnetic flux. The diameter of the high voltage winding in the inventive transformer is smaller than in a U-shaped transformer, where it is located on top of the primary one. This greatly reduces the length and resistance of the wire and the scattering field. This leads to an increase in the quality factor of the circuit and an increase in the amplitude of the voltage across the winding of the higher voltage.

In the inventive transformer, the insulation problem of the high voltage winding is greatly facilitated.

The location of the high voltage winding on the outer rods facilitates the heat removal problem, which increases the reliability of the converter.

Such a transformer opens the possibility of reducing interference and increases the reliability of the converters, significantly increasing their efficiency.

Tests of the high-voltage source showed that the power supply used to create an output voltage of 200 kV is 40% less with the claimed transformer than with a U-shaped transformer. The voltage on the semiconductor element (field effect transistor) is half as much when the converter is operating with the inventive transformer than with a U-shaped one.

The inventive transformer is supposed to be used in a high voltage converter for conducting experiments on measuring the electric dipole moment of a neutron at the PNPI FSBI in the installation of an EDM spectrometer.

Literature

1. A. Abramyan, B. A. Alterkop, G. D. Kuleshov, Intense electron beams, M., Energoatomizdat, 1984.

2. A.M. Dymkov, V.M. Kibel, Yu.V. Tishenin. Voltage transformers. Moscow. "Energy".

3. S. S. Vdovin, Design of pulse transformers. L., Energoatomizdat, 1991, 208 p.

4. Questions of radio electronics. The series is general technical. 1970, N18. L.K. Buevich, V. B. Gaase. Some questions of constructing circuits of high-voltage power supplies of cathode ray tubes.

5. Patent RU No. 2199786. MPC ⁷ H01F 30/10.

6. Patent WO 2004/04060, IPC H01F 27/28; H01F 29/14 - prototype.

7. Power electronics. N2, 2007. V. Lantsov, S. Eranosyan. Electromagnetic compatibility of switching power supplies.

8. V. Lantsov, S. Eranosyan. Quasi-resonant power sources: problems, a new look. Power Electronics, N3, 2007.

Claims (1)

A w-shaped transformer containing one winding of low voltage, two windings of higher voltage, characterized in that the winding of the lower voltage is located on the central terminal of the transformer, and each of the windings of the higher voltage is located on the corresponding extreme terminal of the transformer, and the higher voltage windings are made in the opposite direction winding.

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