RU2210149C2 - Metalclad switchgear - Google Patents

Abstract

FIELD: electrical engineering. SUBSTANCE: metal-clad switchgear designed for three-phase power distribution at frequency of 50 and 60 Hz and at voltage of 6-10 kV has draw-out component provided with mechanism for setting it in working and check-up positions and vice versa with doors held closed. Metal strip mounted bushing is provided in partition inserted between collecting-bus compartment and drawout component compartment. Bottom current-conducting contact is fixed to current transformer. Insulating partition fitted between compartments of current transformer and draw-out component has air clearance ensuring air insulation for bottom fixed conducting contact of cubicle and movable contact of draw-out component. Doors provided with lifting and locking device are tightly fitted over perimeter of opening in draw-out component compartment. EFFECT: enhanced safety in servicing. 1 cl, 5 dwg

Description

 The invention relates to the field of high-voltage apparatus engineering, including the design of enclosures of complete switchgears (hereinafter referred to as switchgear) of an indoor installation in a metal shell [1].

 The well-known switchgears, commercially available, are standardized by withdrawable elements with vacuum, low-oil and gas-insulated circuit breakers and are designed to receive and distribute electric energy of three-phase alternating current with a frequency of 50 and 60 Hz, voltage of 6-10 kV [2].

 The well-known switchgear, commercially available in Ukraine and abroad, should include those that have the same weight and technical and economic indicators and parameters, as well as the ability to be equipped with withdrawable elements with new generation vacuum circuit breakers (for example, VD4, VM1S, BBKE-10, BB / TEL).

 Such switchgears should include foreign analogues: ZS8 firms CALOR-EMAG (Germany), K-104M MEShch (Russia), K-IN96 NVF "Inosat" (Belarus) and KU-10 manufactured by SP RZVA (Ukraine).

 To obtain the expected result and for the largest number of similar significant features of the proposed invention, the switchgear KU-10 manufactured by the joint venture RZVA (Ukraine) was adopted as a prototype [3].

 The present invention, like the prototype, consists of the following components: a frame, a compartment of current transformers, a compartment of busbars, a relay compartment, a compartment of a withdrawable element, an earthing switch, as well as fixed contacts for the upper and lower conductive switch connectors.

 Significant disadvantages of the prototype include the fact that the withdrawable element with a switch, after moving it from the working position to the control, goes beyond the dimensions of the switchgear cabinet. In this case, the opening of the main conductive contacts under rated voltage is dangerous for the operating personnel of the substation, because the degree of protection of the prototype during this movement is IP00 (for the control position of the withdrawable element) [4]. The aforementioned drawback significantly narrows the scope of such switchgear, and especially in operating conditions in the presence of conductive oxide salts (for example, in potash mines, in salt mines and other adverse facilities of this nature).

 In the prototype, the door function is performed by the front sheet of the withdrawable element, which is less reliable than the doors that tightly cover the facade area of the withdrawable element compartment, which is quite significant for the localization mode.

 The disadvantages of the prototype should also include the fact that the withdrawable element, being in the control position, significantly narrows the service corridor. In the present invention, the withdrawable element with the switch is in the control position within the switchgear cabinet.

 Significant disadvantages also include the fact that the insulating bushings and textolite plates are made of organic material, which over time loses its electrical strength, which decreases the electrical strength of the insulation of the switchgear as a whole, which in due time can cause emergency situations during operation.

 The proposed switchgear was developed using new design solutions that completely eliminated the aforementioned disadvantages of the prototype, while not only the technical and economic parameters were saved, but the overall dimensions were saved and the highest degree of protection of the switchgear was achieved at the control position of the withdrawable element. The possibility of using a withdrawable element with a mechanism for moving from the worker to the control position and vice versa, a number of design innovations, as a result of achieving the goal, are, according to the authors, an advantage over similar types of switchgear and a prototype and are used in the proposed invention of a complete switchgear.

 The basis of the invention is the task of creating a new type of switchgear cabinet with increased service safety. In the proposed complete switchgear, the goal is achieved by using a special withdrawable element with a switch with the ability to move it from the working position to the control and vice versa, fixing it in these positions while maintaining the locking, control and alarm systems, air insulation between the lower conductive fixed contacts of the transformer compartment current, and front doors that fit tightly around the perimeter of the opening of the drawout element compartment.

 The said withdrawable element is a collapsible metal structure consisting of a lower frame base and an upper movable base with a switch located in only one fixed position relative to the switchgear cabinet. Fixing of the base is carried out by a rod, which enters the groove of the retainer at the bottom of the cabinet and stops the spontaneous movement of the base. Moving the movable part of the withdrawable element relatively motionless (from the working position to the control and vice versa) is carried out by a movement mechanism forming a screw pair: nuts on the movable base and a screw mounted on the conditionally stationary base of the frame. When the screw rotates, the movable part moves along the guide grooves of the base on the rollers mounted on the brackets.

 Figure 1 shows the switchgear of the KU-10Ts series with a withdrawable element with a switch in the working position; figure 2 - element (callout A) with the placement of the fixed upper and lower conductive contacts of the switchgear and the movable upper and lower conductive plug connectors of the switch; figure 3 - the front door of the compartment withdrawable element from the middle of the switchgear (type B); figure 4 is a view of B and figure 5 is a view of G is a lifting-rotary locking device.

 The switchgear of the KU-10Ts series (Fig. 1) consists of the following main parts: frame 1, compartment of current transformers 2, compartment of busbars 3, relay compartment 4, compartment of withdrawable element 5, current transformers 6, ground electrode 7.

 The upper fixed conductive contact 8 (figure 2) is fixed by fastening 9 to the inner part of the bushing 10, which is fixedly mounted on the metal plate 11, instead of the bushing with a wood-laminated fiber (DSB) on the textolite plate as in the prototype. The upper movable conductive contact switch of the withdrawable element switch 12 through the receptacle is reliably connected to the stationary conductive contact 8 in the middle of the bushing.

 The use of insulating partitions 13, forming an air gap (see Fig. 2), provided air insulation for the lower fixed conductive plug connectors of the circuit breaker and conductive contacts 14, reliably fastened to current transformers by bolts 15. This made it possible to refuse bushings made of wood-fiber plastic (fiberboard) on a textolite plate, since the said insulating partitions 13 (Fig. 2) fully provide for the partitioning of the current transformer compartment and the drawout element compartment redlozhennogo KRU [5].

 The shutter mechanism of the cabinet automatically when moving the withdrawable element to the repair position blocks access to the conductive parts of the upper and lower contacts of the KU-10TS cabinet.

 The use of the above-mentioned new design solutions in combination with a new type of roll-out element made it possible to introduce doors 16 into the design of the KU-10TS cabinet (Fig. 3). Doors with a lifting-and-turning locking device (Fig. 4; Fig. 5) tightly close the front slot of the draw-out element compartment around the entire perimeter, increase the localization resistance of the draw-out element compartment, which provides reliable protection for maintenance personnel. The window 17 of transparent material allows you to monitor the position of the mechanical pointers of the switch and withdrawable element. The plate 18 closes the holes for the levers of operational manipulation of the switch and the withdrawable element with the doors closed. The door lifting and rotating locking device consists of a lever 19 (FIG. 4, view B), a rod 20, an arm 21 connected to the above lever and a link by two rods 22 (FIG. 5, view D).

 Axis 23 (Fig. 3) connects the system of levers with the rotary axis 24 of the door opening handle, and the latter with a lock nut 25 connects this axis to the sleeve 26 of the lift-and-lock door lock device.

 The general principle of functioning of switchgear is based on the distribution of electricity to the consumer from a common power source. In the switchgear cabinet of the KU-10TS series, the supply current from the busbars is supplied to the upper fixed conductive contacts, then passes through the on switch installed on the withdrawable element located in the working position in the cabinet, through the lower fixed conductive contacts and the current transformer, and the power cable enters to the consumer.

 The proposed technical solutions make it possible to improve the technical, economic and overall dimensions, make it possible to expand the range of application of the proposed switchgear of the KU-10Ts series and classify it as a switchgear with increased service safety.

 The prototype switchgear of the KU-10TS series manufactured at the Rivne High-Voltage Equipment Plant fully confirmed its compliance with the standards for switchgear, as shown by the tests for switching, localization, thermal and dynamic resistance, conducted at the SRC VVA in Moscow (Russia), and readiness for operation national economy.

Sources of information
1. GOST 14693-90 "Complete distribution devices not sealed in a metal sheath for voltages up to 10 kV." Standards Publishing House, 1990

 2. Complete switchgear KU-10. Avenue. , JSC "Rivnenska drukarnya", 1995, 31 p.

 3. Doroshev K. I. Operation of complete switchgear 6-220 kV. M .: Energoatomizdat, 1997, 835 s.

 4. GOST14252-80 "Electrotechnical products. Shells. Degrees of protection". Standards Publishing House, 1980

 5. IEC 298. "Complete AC switchgears in a metal sheath for voltages from 1 to 72.5 kV." M., 1981

Claims (1)

 Complete switchgear comprising a frame, a compartment of current transformers, a compartment of busbars, a relay compartment, a compartment of a withdrawable element with movable contacts, an earthing switch, fixed upper and lower conductive contacts, characterized in that the withdrawable element has a mechanism for moving from the worker to the control position and vice versa with closed doors, and in the partition between the busbar compartment and the drawout element compartment, a bushing is installed on a metal plate, to the inside of which it is fixed the upper fixed conductive contact is connected, which in the middle of the bushing through the plug socket is connected to the upper movable plug conductive contact of the withdrawable element in the working position, the lower conductive contact is fixed to the current transformers, allowing current to pass through them and the current transformer in the working position of the withdrawable element, wherein the partition of insulating material between the current transformer compartment and the withdrawable element compartment has an opening, and the doors lifting-rotational locking device fit snugly around the perimeter of slit withdrawable unit compartment.

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