RU2573604C2 - Connection module - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: connection module comprises an isolating transformer of coaxial type with an open magnetic conductor, onto the primary winding (1) of which outside and at the side of its fixation to the CM (3) body there are copper magnetic screens (10) installed, the secondary winding (2), fixed to a high-voltage connector (4), which in its turn is installed on the rear wall of the CM body, a current transformer (5), a high voltage bleeder (7), the upper arm of which is made in the form of a structural reservoir, a water cooling system (6), arranged in the expansion volume of the CM body, a unit of control sensors (8) and a unit of oil filling and drainage (9).

EFFECT: improved operating characteristics and simplified design of a connection module.

3 cl, 2 dwg, 11 dwg

Description

 The present invention relates to the field of electrical engineering, and in particular to a power supply device for horizontal multipath klystrons, for example: Toshiba Electron Devices (E3736H), Thales Electron Devices (TH 1802), Communications and Power Industries (VKL 8301B).

It is worth noting that these klystrons are specially designed for the European XFEL project and have a flange connection of the KF type (Kwik-Flange) on the cathode side. However, connecting them to a pulse transformer turned out to be extremely difficult in a tunnel due to reasons:

- The large weight of the klystron with a transport platform (about 3.5 tons) makes it practically inactive. Which greatly complicates the connection of klystrons with pulse transformers.

- In the XFEL tunnel, restrictions on working with mineral oils have been introduced and the use of synthetic liquid dielectrics is prohibited. According to the specification, the cathode volumes of klystrons must be filled with a liquid dielectric based on mineral oil.

Based on these reasons, it was proposed to connect klystrons to pulse transformers through a special unit - the Connecting module (hereinafter SM) and high-voltage cable connection. The connection module consists of a housing, on one side of which a flange connection of the KF type (Kwik-Flange) is made, and on the other side a high-voltage connector of the Pfisterer 3 / S type is installed. Inside the housing, the Connection module contains a coaxial type isolation transformer with an open magnetic circuit, a current transformer, a high voltage voltage divider, a water cooling system, a control sensor unit, an oil filling and draining unit.

The technical result consists in improving the operational characteristics and simplifying the design of the Connection module.

The prior art device is known consisting of a separation transformer of a coaxial type with an open magnetic circuit. / V.E. Balakin, V.F. Kasitsky, V.V. Kobets et al. High-voltage power supply system project for the VLEPP complex. Proceedings of the 12th All-Union Conference on Charged Particle Accelerators. Dubna. 1992, October 3-5, pp. 260-263 /. The housing of this device on both sides is made under the flange connection. The known device is unable to provide flexibility in connecting the klystron to a high-voltage power source, it does not have sensors for measuring the current and voltage of the klystron, it provides a cooling system due to heat transfer to the environment, which is extremely undesirable in operating conditions of the XFEL tunnel.

Closest to the claimed technical solution (prototype) is a device including a coaxial type isolation transformer with an open magnetic circuit, a current transformer, a capacitive voltage divider, a water cooling system, oil level and temperature sensors, a high-voltage insulator / V.Vogel, A. Cherepenko , S. Choroba, J. Hartung, P. Bak, A. Korepanov, N. Evmenova. Connection module for the European X-ray FEL 10 MW horizontal multibeam klystron. Proc. IP AC 10, Kyoto, Japan, THPEB043, 2010 /. The case of this device has a flange connection of the KF type on one side, and a high-voltage connector of the ESSEX R28 type on the other. The disadvantages of this technical solution are: insufficient electromagnetic shielding of a coaxial type isolation transformer with an open magnetic circuit, inefficient design of a water cooling system, the device is excessively complicated by the use of a high voltage insulator, low reliability of the cable connection based on a high voltage connector of the ESSEX R28 type.

The objective of the invention is to remedy the above disadvantages by changing the design of the Connection module.

This problem is solved by the fact that in the Connection module containing the housing, on one side of which there is a flange connection of type KF, and on the other hand, a high-voltage connector, including a coaxial type isolation transformer with an open magnetic circuit, a high-voltage voltage divider, current transformer, water the cooling system according to the invention, screens from a non-magnetic electrically conductive material are installed outside and from the end of the primary winding of the coaxial type isolation transformer, second The coils of the coaxial type isolation transformer are mounted on the end of the high voltage connector, and additional plates are added to the tubes of the water cooling system.

Distinctive features of the invention are:

- from the end and the outer side of the primary winding of the coaxial type isolation transformer, screens of non-magnetic electrically conductive material are installed (which reduced the level of electromagnetic radiation of the isolation transformer);

- the secondary winding of the isolation transformer is fixed to the end of the Pfisterer 3 / S connector (which made it possible to simplify the design of the Connection module by eliminating the high-voltage insulator);

- additional U-shaped plates were added to the water pipes of the cooling system (which expanded the permissible operating temperature range of the SM);

- instead of the high-voltage connector ESSEX R28, the high-voltage connector Pfisterer 3 / S was used (which completely eliminated damage to the cable connection due to insufficient electrical strength of the connector ESSEX R28 with a pulsed nature of operation.

 This increased the reliability of the connection module.

The invention is illustrated by drawings, which depict:

In FIG. 1 - general view of the SM;

In FIG. 2 - a method for connecting klystrons of horizontal execution TH 1802 to a pulse transformer through SM;

In FIG. 3 - equivalent circuit isolation transformer;

In FIG. 4 - execution of VDN;

In FIG. 5 - location of the control sensors block;

In FIG. 6 - temperature measurement zones in the SM during thermal tests;

In FIG. 7 is an isometric view of a radiator of a water cooling system.

The design of the proposed CM shown in FIG. 1, contains a coaxial type isolation transformer with an open magnetic circuit, on the primary winding (1) of which outside and from the side of its fastening to the SM case (3) copper magnetic shields (10) are installed, the secondary winding (2) fixed to the Pfisterer 3 high-voltage connector / S (4), which in turn is mounted on the back wall of the SM case, a current transformer (5), a high voltage voltage divider (7), the upper arm of which is made in the form of a structural tank, a water cooling system (6) located in the expansion volume to SM case, control sensors block (8) and oil filling and draining unit (9).

A connection module, the construction and method of application of which is shown in FIG. 1, 2, works as follows.

Before transportation to the tunnel, the SM is connected to the horizontal klystron using a flange connection of the KF type. The first operation at the connection stage is the wire connection of the cathode and klystron heater to the corresponding SM electrodes (11). After joining, the SM volume and the cathode volume of the klystron are filled with mineral oil through the oil filling and draining unit (9) to the calculated level based on the oil temperature and type of klystron. Then, the volume of the SM is hermetically sealed with a cover with a block of control sensors (8). The air dryer oil (12) is filled with silica gel.

In the tunnel, the klystron-SM assembly and the pulse transformer in the free position are connected by a high-voltage cable connection through the Pfisterer 3 / S connectors for powering the klystron cathode (Fig. 2).

Power transfer to the klystron cathode heater in the SM was performed through a coaxial type isolation transformer with an open magnetic circuit. This transformer design optimally provides a high-voltage isolation between the primary and secondary windings, but has a magnetic coupling coefficient between the windings k substantially less than unity.

where: L1 is the inductance of the primary winding, L2 is the inductance of the secondary winding, M is the mutual inductance.

Efficient power transfer in such a transformer is possible using two oscillatory circuits tuned to resonance (Fig. 3).

The conditions for obtaining the maximum efficiency of this circuit are as follows:

1. Natural frequencies of circuits

must be equal to each other and to the frequency of the generator ƒ.

2. The loaded quality factor of the secondary circuit should be equal

where: Q _2H is the loaded Q factor of the secondary circuit. / U.D Valyaev, I.V. Kazarezov, V.I. Kuznetsov, V.P. Ostanin. Small-sized high-frequency isolation transformer for powering devices located at high potential. Preprint INP SB RAS USSR, 89-160. Novosibirsk, 1989.

The scattering magnetic fields of a coaxial transformer with an open magnetic circuit are effectively shielded by installing copper screens (10). Considering the effect of the "skin effect" (in our case ~ 1.7 mm) when installing 2 mm thick copper shielding rings, we reduce the induction of the scattering magnetic field on the surface of the SM housing to 1 Gauss, and on the transformer axis (in the region of the cathode cathode flange) to 0.4 Gauss .

The current transformer (5) is designed as built-in, without its own primary winding. The primary winding is played by the potential electrode of the Pfisterer 3 / S high-voltage connector. The secondary winding is wound on a toroidal magnetic circuit.

The high voltage voltage divider (VDN) is designed according to the principle of a capacitive divider with a design capacitance on the high voltage side, formed by the gap (A) between the electrostatic screen mounted on the cathode of the klystron and a round plate fixed to the vertical wall of the flange connection (Fig. 4). The choice of this tank design on the high voltage side is justified, first of all:

- reliability. The gradient of the electric field in this region is <35 kV / cm;

- simplicity and manufacturability, which is very important in serial production.

The control sensors block is located on the upper removable cover SM (Fig. 5). This location allows you to diagnose and, if necessary, replace the sensors simply and affordable. There are three types of sensors in the SM that provide control of the maximum and minimum permissible oil levels; oil temperature and its humidity.

.The water cooling system SM is assembled on the basis of a seamless copper tube with an inner diameter of 12 mm and a total length of 3 m, twisted inside the expansion volume of the SM. To increase the heat removal area, horizontal sections of the tube are additionally soldered with U-shaped copper plates 1 mm thick. Thus, a total radiator area of 0.43 m ² with thermal resistance was achieved. $$0.05\frac{\mathrm{TO}}{\mathrm{AT}t}$$

.

The effectiveness of the water cooling system is experimentally confirmed by the uniformity of the temperature field picture inside the SM volume and the klystron.

The supply and discharge of water to the cooling system is done via quick disconnect connections type SP 3 manufactured by Nitto-Kohki.

The oil filling and draining unit is located at the lowest point of the SM, which minimizes the possibility of air sinuses when filling the volume with oil and achieves complete oil drainage during pumping. The oil filling and draining unit is made in the form of three main parts: fitting GF-143R (Schwer), angle crane ITO298 (Itap), quick-disconnect fitting type DDC-V 25-1 (Elaflex).

Testing of the first SM sample, conducted in DESY (Germany), and their subsequent series of 33 pieces for the XFEL project confirmed that the claimed design of the Connection module:

- provides reliable operation and convenient connection of horizontal klystrons of the Toshiba Electron Devices (Е3736Н) type, Thales Electron Devices (TH 1802), Communications and Power Industries (VKL 8301B) through a high-voltage cable version to a pulse transformer;

- due to magnetic screens installed on the outside and at the end of the primary winding of the isolation transformer, the induction of the transformer’s magnetic field on the surface of the SM housing is 3 times lower, on the transformer axis (in the region of the cathode flange of the klystron) 2.5 times lower than that of the prototype;

- due to the installation of additional U-shaped plates on the water cooling system, the heat resistance of the radiator is 4 times lower than that of the prototype;

- the exclusion of a technologically sophisticated product - a high-voltage insulator from the claimed construction of SM allowed to simplify the assembly and reduce the cost of manufacturing SM by 11%.

Claims (3)

1. A connecting module for power supply of horizontal klystrons, comprising a housing made of corrosion-resistant steel (alloy) with low magnetic permeability, on one side of which there is a flange connection, and on the other hand, a high-voltage connector, with a high-voltage voltage divider, current transformer located inside the housing, water cooling system, coaxial type isolation transformer with open magnetic circuit, characterized in that on the outside and from the end of the primary winding of the separator coaxial type transformer installed screens of non-magnetic electrically conductive material. 2. The connecting module according to claim 1, characterized in that the secondary winding of the separation coaxial transformer is mounted on a high-voltage connector. 3. The connecting module according to claim 1, characterized in that the radiator of the water cooling system located in the upper part of the housing has a thermal resistance of not more than $$0.05\frac{\mathrm{TO}}{\mathrm{AT}t}$$

.

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