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Title:
ON LOAD SECTIONING ASSEMBLY FOR EXTERNAL USE 3KV 3KA
Document Type and Number:
WIPO Patent Application WO/2019/073499
Kind Code:
A1
Abstract:
On load Sectioning Assembly, comprising a Contact Group (100) comprising an electric contact blade (117) connected to a drive shaft (119); a support pole (309) resting on a ground base (350); and a Maneuvering Group (200) for operating a kinematic drive for opening and closing the Contact Group (100). The kinematic drive comprises a first rod (301) connected to said electric contact blade (117) through said drive shaft (119), and a second rod (302), substantially parallel with respect to and at a distance not equal to zero from said first rod (301), connected to said Maneuvering Group (200) so as to be moved by said Maneuvering Group (200), wherein the first rod (301) and the second rod (302) are connected to respective ends (304,305) of a rigid rocker (306) pivoted to a central pivot (307) connected to said support pole (309).

Inventors:
TINTI, Gianfranco (Via Traspontina 40, Pavona di Ariccia, 00040, IT)
Application Number:
IT2018/050186
Publication Date:
April 18, 2019
Filing Date:
October 09, 2018
Export Citation:
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Assignee:
TECNOLOGIE MECCANICHE S.R.L. (Via Traspontina 40, Pavona di Ariccia, 00040, IT)
International Classes:
H01H31/28; B60M3/00; H01H3/24; H01H3/46; H01H31/30; H01H1/42
Foreign References:
EP1536444A12005-06-01
US3349207A1967-10-24
DE2351492A11975-04-24
US20160055997A12016-02-25
Attorney, Agent or Firm:
SANTI, Filippo et al. (Via Piemonte 26, Rome, 00187, IT)
Download PDF:
Claims:
CLAIMS

1 ) On load Sectioning Assembly, comprising:

- a Contact Group (100) comprising an electric contact blade (1 17) connected to a drive shaft (1 19);

- a support pole (310) resting on a ground base (350); and

- a Maneuvering Group (200) for operating a kinematic drive for opening and closing the Contact Group (100) connected to said drive shaft (1 19), the Maneuvering Group being fixed to said support pole (310); the Sectioning Assembly being characterised in that the kinematic drive comprises a first rod (301 ) connected to said electric contact blade (1 17) through said drive shaft (1 19), and a second rod (302), substantially parallel with respect to and at a distance not equal to zero from said first rod (301 ), connected to said Maneuvering Group (200) so as to be moved by said Maneuvering Group (200), wherein the first rod (301 ) and the second rod (302) are connected to respective ends (304,305) of a rigid rocker (306) pivoted to a central pivot (307) connected to said support pole (309).

2) Sectioning Assembly according to claim 1 , wherein the Maneuvering Group (200) is an oleodynamic group.

3) Sectioning Assembly according to claim 1 or 2, wherein the Contact Group (100) a base frame (1 12) to which a plurality of insulators (102, 1 10) are fixed, one (1 10) of the plurality of the four insulators being tilted with respect to the base (1 12) to actuate by its tilting two microswitches (1 14) comprised in said base (1 12).

4) Sectioning Assembly according to any one of claims 1 to 3, wherein a wall in contact with the electric contact blade (1 17) is painted with a dielectric.

Description:
ON LOAD SECTIONING ASSEMBLY FOR EXTERNAL

USE 3KV 3KA

The present invention concerns an On load Sectioning Assembly. More in detail, the present invention concerns a sectioning assembly to be used in the railway field, that is an electromechanical organ inserted in an electric circuit in order to cut, that is to open a circuit or a line, as a prescribed choice of insulation, in a physical and visibly evident way.

Prior art

Sectioning assemblies already exist for use in railway installations.

The document "Specifica di Fornitura - Complesso di Sezionamento Sotto Carico per Esterno 3kVcc - 3kA" [document: RFI DMA IM TE SP IFS 005 0] and subsequent derogations sets out the specifications for the Italian rail network.

Already existing sectioning assemblies present the following problems and drawbacks:

• contact resistors; this constitutes, in the input-output chain, the main cause of loss, even if limited to a few μΩ. A choice of the double contact sectioning, even if it has theoretical advantages for the reduction of the contact resistance, results to have some intrinsic problems due to the difference of resistance of the two contacts. With a high current pulse, a sufficient electromagnetic field may be generated to open the contacts (see Figure 1 );

· Not very good weight distribution and insufficient controllability of system targets;

• Hand operation and remote control are separate, making both routine and extraordinary maintenance difficult;

• The transmission of motion from the Maneuvering Group to the Contact Group is traditionally made with two parallel steel cables, and suffers the thermal expansion due to temperature changes. This may lead to loss of remote control, as the slightest contact movement in the Contact Group may not close the limit switches. The purpose of the present invention is to provide an On Load Sectioning Assembly that solves the problems and overcomes the drawbacks of the prior art.

It is an object of the present invention an On load Sectioning Assembly according to the enclosed claims, which form an integral part of the present description.

The invention will now be described for illustrative but not limiting purposes, with particular reference to the drawings of the attached figures, in which:

- figure 1 shows a Contact Group;

- figure 2 shows a Maneuvering Group;

- figura 3 shows un Sectioning Assembly secondo the invention; and

- figura 4 shows a functional block diagram of the Sectioning Assembly according to the invention.

It is here specified that elements of different embodiments may be combined together to provide further embodiments without limits within the technical concept ofthe invention.

The present description also refers to the prior art for its implementation, with regard to the characteristics of detail not described, such as elements of minor importance usually used in the prior art in solutions of the same type.

When an element is introduced, it always means that it can be "at least one" or "one or more".

When listing a list of features or elements in this description it is intended that the invention according to the invention "comprises" or alternatively "is composed of" such elements.

In the Sectioning Assembly according to the invention the following choices were made:

- Single sectioning to avoid the formation of a loop when the Sectioning Assembly is in the CLOSED position. The choice of double-contact sectioning, although presenting theoretical advantages for the reduction of contact resistance, results to have intrinsic problems due to the difference in resistance of the two contacts. With a high current pulse, a sufficient electromagnetic field may be generated to open the contacts (see Figure 1 );

- Maintenance of the device geometry, able to break the possible electric arc, closer to the current solution because it is strongly tested and consolidated. Alternative solutions do not guarantee the same performance due to the difficulty of modeling the electric arc (see Figure 1 );

- Division of the Complex in three groups: Contact Group , Maneuvering Group and Linking Cinematism. This allows to obtain, in addition to a better weight distribution, also a specialization of the tasks for groups with consequent greater controllability of the system targets (see Figure 3);

- Adoption of an oleodynamic movement in substitution of the previous mechanical system (with springs). Given the speeds and accelerations required for handling, this solution allows an easier accumulation of energy to be released in a short time at the time of the opening request (see Figure 2);

- Concentration of all active organs in the Maneuvering Group . In this way it is possible to integrate in the same system the manual manoeuver and the remote control. Maintenance, both ordinary and extraordinary, is also facilitated (see Figure 2);

- Transmission of the motion from the Maneuvering Group to the Contact Group through the purely mechanical Linking Cinematism (rigid rods), designed to compensate for thermal expansion to temperature variations (see Figure 3).

Referring to FIG. 1 , in an embodiment, the Contact Group 100 is composed of a base frame 1 12 to which four insulators 102 and 101 are fixed , which are designed to withstand 125 kV of insulation. The operation of the insulator 101 is different from the homologous one of the prior art. In the prior art, the counterpart of 101 moved vertically, while in the invention the insulator 101 tilts. Within 1 14 there are two microswitches (not shown) to check the position of the Main Contact (blade) 1 17. The two microswitches 1 15 work together with the microswitch 1 14 to verify this position of the blade 1 17. The fact that the insulator 101 tilts is to improve, according to the invention, the microswitch drive system. In fact the microswitches 1 14 are now parallel and can be contacted by tilting of the insulator 101 , whereas before they were in a row and were contacted for greater penetration of the insulator 101 which, however, sometimes blocked not allowing contact verification.

There blade 1 17 is according to the prior art.

Elements 104, 109 are only covers, possibly also made of plastic. Elements 106, 107 are called Spinterometric Horns and are the same as those of the prior art. However, in the prior art the material of the horns was iron, in the present invention steel is preferred.

The Sacrifice Contact 1 16, having the purpose of preventing the arc from engaging in the Primary Contact and accompanying it towards the Spinterometric Horns 106 and 107, is according to the prior art.

The elements 105 and 108 are sheet metal boxes for support of the horns. Element 108 also provides support for the movement mechanism of the insulator 101 .

The element 1 13 is the cover of the Female Main Contact 1 18. This element, and the outer walls of the covers 105 and 108, are treated with an insulating dielectric varnish in such a way as to create a mandatory arc path towards the Spinterometric Horns 106 and 107.

Elements 103 are terminals connected to the power line.

The elements 1 1 1 are the fixing nuts of the insulators 102.

Element 1 10 is a junction box which is connected up to the

Maneuvering Group 200 (see Fig. 2).

Referring to Figure 2, the element 201 is the envelope of the Maneuvering Group .

Element 203 is the oleodynamic unit that has the purpose of carrying out the movement. In the invention it replaces the traditional electromechanical handling with preloaded springs. This has a dimensional and weight advantage. Element 202 is the interface terminal block with the pre-existing railway system not included in the invention .

Referring to Figure 3, in its complete configuration, the Sectioning Assembly of the invention comprises the Contact Group 100, the Maneuvering Group 200 and the Linking Cinematism 300. The post 309, the Shelf 310 and the base 31 1 , to which the post 309 is fixed, are part of the existing railway system and are not comprised in the invention .

The Linking Cinematism 300 consists of the Return Group 303 and two adjustable rods 301 and 302.

The invention uses a first rod 301 connected to the main contact

(blade) 1 17 through the drive shaft 1 19 (known, figure 1 ). The rod 301 is moved by the oleodynamic system 203, being part of the Maneuvering Group 200 (Figure 2), through the referral group 303 and a parallel shaft 302.

The first rod 301 and the second rod 302 are connected to

Respective ends 304, 305 of a rigid rocker 306 pivoted to a central pivot 307 connected in 308 to support pole 309.

This arrangement, according to the invention, replaces the double driving rope of the prior art which, with the variation of the temperature, lost control due to the variation of the length of the cords, with the risk of not being able to operate the contact.

In contrast, in the present invention the return system compensates for the loosening and the tension due to temperature variations. In fact, thanks to the return system only the inclination of the rocker changes, and this does not affect the transmission ratio between the maneuvering group and the head of the sectioning assembly at the top. In fact, the Linking Cinematism 300 is designed to compensate for the expansion and contraction of the material due to temperature variation.

Making reference to Figure 4, the Functional Scheme of the Sectioning Assembly according to the invention is shown. In reading the diagram in Figure 4:

- The two HW adaptation blocks 402, 403 make the interface to the existing RFI 401 system in such a way as to allow interchangeability without making any changes to the system itself.

- The Sectioning Assembly state reading 404, which provides position control, does not have direct interactions with the handling section, being intended solely for certification of the successful opening or closing.

- The OPENING block 406, activated by the opening command 405, encloses the sections involved in the Sectioning Assembly opening action according to the invention, triggered by the receipt of the opening command; and

- The CLOSING 408 block, activated by the closing command 407, contains the sections involved in the closing action of the Sectioning Assembly according to the invention, triggered by the receipt of the closing command.

More in detail, the opening block 406 comprises an energy-storage oleodynamic drive section 409, a section of the Minimum Pressure Switch 410, a Drive/Discharge Solenoid Valve section 41 1 , a section of the Safety Valve 412.

In detail, the Closing block 408 comprises a section of Maximum Pressure and Maintenance Pressure Switch 413, a section of Checking Oil Level in Tank 414, a section of Accumulation/Action Pilot Electrovalve 415, a section Pump Motor group 416.

Depending on the application context, the group according to the invention is distinguished in two versions, with Excitation and De-excitation . It is noted, however, that at a high level the two versions are equivalent, specializing only in the implementation detail which provides:

- The same mechanical solution

- The same type of interface

- The same oleodynamic architecture

- The same Sectioning assembly status reading block with the same HW adaptation

- The specialization of HW Adaptation dedicated to oleodynamics

- The specialization of the Solenoid valves EXCITATION sectioning Assembly DETERMINATION

sectioning Assembly

With the manual Maneuver it is With the manual Maneuver only the possible to perform both the Opening opening action can be performed.

and closing action.

In the absence of power supply to the In the absence of power supply to the Maneuvering Group , the main Maneuvering Group , the main contact remains in the state it was at contact opens.

the moment before the interruption.

When the door is opened, the system Opening the door does not cause the remains in the state it was at the main contact to open.

previous instant.

For both solutions compliance is guaranteed with the most stringent requirements, and in particular:

1 . Overall resistance of the circuit: <50

2. Holding voltage at 50Hz between fixed and mobile contacts and ground > 50kV

3. Holding voltage at 50Hz on the sectioning distance: > 60kV

4. Maximum time of mechanical opening: <100ms

5. Maximum closing time: <2s (One of the objectives of the solution is to make closing time comparable with the opening time)

. Mechanical life: > 5000 A / C cycles

By means of the solution according to the invention, the following advantages are obtained, among others:

1 ) The transmission of the motion between the Maneuvering Group and the Contact Group takes place through a Linking Cinematism, designed to compensate for variations in materials due to thermal excursion.

This solution solves the problem of constant calibration and maintenance required on today's systems, which adopt a transmission system consisting of steel cables. Due to the thermal expansion of the material, the cables tend to become loose causing a loss of control.

2) Adoption of an oleodynamic movement in substitution of the previous mechanical system (with springs). This solution allows to have high performances, in terms of forces and speed, maintaining reduced dimensions.

3) Concentration of all active organs in the Maneuvering Group . In this way it is possible to integrate in the same system the manual Maneuver and the remote control, making the installation and the maintenance (ordinary and extraordinary) easier.

In the foregoing the preferred embodiments have been described and variants of the present invention have been suggested, but it is to be understood that those skilled in the art may make changes and modifications without thereby abandoning the relevant scope of protection, as defined by the appended claims.