SU593329A1 - High-voltage transformer-rectifier - Google Patents

Description

one

The invention relates to high voltage power sources and can be used in accelerator technology, as well as for laboratory and industrial purposes.

High voltage power sources for accelerators are known, made on the basis of transformers placed in a casing filled with an electrical insulating medium .1. The disadvantage of such devices is the weak protection of the high-voltage winding of the transformer against impulse voltages with a steep front (for example, during training or random nrobo x).

Also known is a high-voltage power supply with voltage rectification {2, containing a three-phase transformer, the high-voltage winding of which is made in the form of series-connected flat spirals, diode rectifying blocks connected to the linear winding pins using a single-bridge three-phase rectifier circuit, and high-voltage winding screens, located in a sealed enclosure filled with electrically insulating medium.

As is well known, during breakdowns, the rate of development of a discharge in alegas is approximately 10 s, and since. the geometric dimensions of the device are commensurate with the insulating gaps, the voltage cut-off time at the linear output of the high voltage winding of the transformer becomes commensurate with the discharge time, so the voltage at the secondary winding of the transformer is distributed according to the system's own capacitances. Moreover, the higher the longitudinal capacity of the secondary winding of the Transformer, the less sensitive it is to impulse voltages of high steepness. For this purpose, the high-voltage winding of the transformer is EXECUTED in the form of series-connected flat spirals. But this is not enough to protect the HIGH-VOLTAGE winding FROM high-slope pulsed voltages. The consequence of this is the insufficient reliability of the HIGH-VOLTAGE windings of known SOURCES of supply with respect to overvoltages arising during training and random breakdowns.

The aim of the invention is to increase the reliability of devices by protecting high-voltage windings against pulsed voltages with a steep front.

This goal is achieved by forming linin in the proposed HIGH-VOLTAGE transformer, each of which includes a conductive STEP, which is part of the linear output winding on which rings of ferromagnetic material are worn, the coil with rings located in the gap between the corresponding phase of the high-voltage winding and its screen.

FIG. 1 is a schematic diagram of a high-voltage power supply transformer; in fig. 2 is a cross-section of the forming line; in fig. 3 - sweep forming line.

A high voltage rectifier transformer contains a three-phase transformer consisting of a magnetic core 1, a primary winding 2 and a secondary winding 3, a diode rectifying unit 4 connected to the transformer by a single-bridge three-phase rectifier circuit, power supply 5 of the low voltage winding 2 and a high voltage A terminal 6 located in a sealed enclosure 7 filled with electrically insulating medium, for example sulfur hexafluoride SFe. The line leads of the high voltage winding 3 are connected to the diode rectifying units 4 through forming lines, each of which consists of a conducting coil 8, which is part of a corresponding linear output winding on which rings 9 of ferromagnetic material are worn. One end of the forming line is connected to the main output of the transformer winding, and the other end to the high-voltage screen 10. Conductive coil 8, with rings 9 mounted on it, is partially inside the high-voltage screen 10, and the middle part of coil 8 with rings 9 mounted on it maximum insulation 11 with respect to the shield 10 and the end of the line output of the winding 3. The space 12 between the shield 10 and the winding 3 can be filled with both an SF6 gas and a solid dielectric.

High-voltage transformer-rectifier works as follows.

Primary winding 2 is connected to AC power. The secondary winding 3 generates a high voltage (hundreds of kV), which is rectified in diode rectifying units 4 connected to the transformer circuit via a single-bridge, three-phase rectifying circuit and applied to the load through a high-voltage output 6 (for example, an accelerator tube). In the case of breakdown (training or random), the voltage on the secondary winding is distributed according to the system’s own capacitances (high voltage winding, transformer-rectifier structural elements), as a result of which the overvoltage winding on the high voltage winding leads wives The voltage gradient in the above described structures of a high voltage winding exceeds the normal (before the breakdown) by 15–20 times and more, e. In order to reduce the gradient of the voltage on the first coils in the high voltage winding, a forming line consisting of a conductive coil 8 on which rings 9 of ferromagnetic material are worn is inserted between the end of the linear output of the transformer winding 3 and the rectifying blocks 4 coil 8 and simultaneously contributing active losses to the circuit, as a result of which the front of the overvoltage wave is extended, and the voltage gradients are significantly reduced. Under the influence of a cut-off voltage pulse with an order front time, due to the action of the forming line, the cut-off time of the voltage on the Li-terminal of the winding increases to (0.5-1) 10-s.

Such an implementation of the linear output of the high voltage winding of a transformer allows one to significantly reduce dangerous voltage gradients in the winding under pulsed voltages with a steep front (close to rectangular) and to increase the reliability of the high voltage rectifier transformer. In addition, since the high voltage winding of such transformers is one of the most critical and expensive elements, the introduction of a forming line reduces the likelihood of a high voltage coil failing and, consequently, increases the reliability of the transformer-rectifier and reduces operating costs.

Claims (2)

1. Abram n. A. High Current Accelerator Transformer, Novosibirsk, 1970, p. 55. 2. USSR author's certificate number 500719, cl. H 05 H 5/00, 1975. 0 pzzzz;