RU150256U1 - UNIVERSAL TRANSFORMER - Google Patents

Abstract

A universal transformer, including a primary winding, a switch of the connection circuit, including two rails with fixed contacts interconnected with the winding and two rails with movable contacts interacting with them, the first of which contains a star connection circuit providing an input voltage of 10 kV, the second - connection diagram a "triangle", providing an input voltage of 6 kV, characterized in that the switch is additionally equipped with a locking device configured to provide blocking the first rail with a movable contact in the absence of voltage when selecting the operating mode of the transformer "6kV" and blocking the second rail with movable contacts in the absence of voltage when selecting the operating mode of "10kV".

Description

The utility model relates to electrical engineering, namely to transformers with switching the input voltage from 10 kV to 6 kV and vice versa.

A well-known universal transformer, selected as a prototype (patent CN 201413760, c. 11.06.2009, op. 24.02.2010), including a primary winding, an input voltage switch, including two rails with fixed contacts interconnected with the winding and two rails interacting with them movable contacts, the first of which contains a star connection diagram providing an input voltage of 10 kV, and the second contains a triangle connection diagram providing an input voltage of 6 kV.

The disadvantage is the insufficient safety level of the transformer.

The problem to which the claimed utility model is directed is to increase the safety level of the transformer.

The technical result is to ensure complete blocking of the operation of the connection circuit of the windings of the "star" during the operation of the connection circuit of the windings "triangle" and vice versa, the exclusion of a short circuit.

To solve the problem, a universal transformer, including a primary winding, a circuit diagram switch, including two rails with fixed contacts interconnected with the winding and two rails with moving contacts interacting with them, the first of which contains a star connection circuit providing an input voltage of 10 kV, the second is a “triangle” connection diagram providing an input voltage of 6 kV; according to a utility model, the switch is additionally equipped with a locking device made with POSSIBILITY ensure blocking of the first rail with the movable contact at the position of zero voltage in the selection mode transformer "6 KV 'and the second blocking slats with moving contacts in the position of zero voltage in the selection mode" 10 kV ".

The utility model is illustrated by drawings.

In FIG. 1 shows a connection diagram of branches of VN windings (high voltage) to a switch with a control range from -5% to + 2 × 2.5%

In FIG. 2 shows a circuit diagram switch.

In FIG. 3 is the same, view A in FIG. 2.

In an example of a specific embodiment, a universal transformer is presented, voltage class up to 10 kV, three-phase power, step-down with natural oil cooling, with switching of the input voltage and branches of the windings without excitation, in a sealed version, included in an AC network with a frequency of 50 Hz, designed to convert electricity in networks of power systems and consumers of electricity.

The transformer includes an active part, a tank, a cover with the HV (high voltage) and LV (low voltage) inputs and the drive of the switch 2 of the connection circuit, which is also connected to the branches of the HV windings for voltage regulation, displayed on the cover 1. The active part is rigidly connected to the cover 1 and consists of a magnetic circuit with windings, including the primary winding, lower and upper yoke beams, high voltage and low voltage taps, switch 2 of the connection circuit. The core type transformer magnetic core is assembled from cold rolled transformer steel. Windings - multilayer cylindrical made: LV and VN from aluminum (copper foil) wire. At the top of the active part there is a switch 2 of the connection circuit and branches of the HV windings. Switch 2 is rigidly fixed to the upper yoke beams. Switch 2 of the connection circuit is designed to change the input voltage from 10 kV to 6 kV and vice versa. It is also used to control voltage without excitation (PBB) by connecting the corresponding branches of the HV windings. Switch 2 is two pairs of rails 3, 4 and 5, 6, mechanically interconnected, on two of which 3, 5 fixed contacts are fixed, and on the other two 4, 6 are movable contacts. To the fixed contacts are connected the adjusting bends of the VN windings in accordance with Fig. 1. On the first rail 4 with moving contacts, a star connection circuit of the windings, providing an input voltage of 10 kV, is assembled; on the second rail 6 with moving contacts, a triangle connection circuit is provided, providing an input voltage of 6 kV. The switch 2 is interconnected with the drive, which contains two handles 7, 8. When one of the handles 7 or 8 of the switch 2 is rotated, the corresponding rail 4 or 6 moves with movable contacts that close the fixed contacts on the rails 3 or 5 with the adjustment taps connected to them transformer windings. The positions of switch 2 are fixed by a special locking device located in the drive inside the transformer tank, as well as by additional latches 9 in the handles 7 and 8 of the drive. Between the handles 7 and 8 is a locking device 10, configured to block the first rail 4 with a movable contact in the low voltage position (hereinafter - 0) when selecting the operating mode of the transformer "6 kV" and block the second rail 6 with movable contacts in position 0 when choosing the operating mode "10 kV". The locking device 10 consists of locking plates 11 and a handle 12 with a latch 13 and eliminates the possibility of rotation of two handles 7 or 8 at the same time.

The device operates as follows.

To switch voltage from 10 kV to 6 kV and vice versa, it is necessary to bring both handles 7 and 8 of switch 2 to the initial position corresponding to 0. To switch voltage from 10 kV to 6 kV, the handle 7 of switch 2 is set to the initial position 0. Knob 12 of the locking device 10 is rotated from a position corresponding to a 10 kV mode to a position corresponding to a 6 kV mode. In this case, the blocking plate 11 closes the handle 7 of the "10 kV" mode, making it stationary, thereby blocking the first rack 4 with movable contacts in position 0. Then, the handle 8 of the "6 kV" mode switches to the position corresponding to the rated voltage VN = 6 kV.

If it is necessary to regulate the voltage, the switch 2 is switched sequentially in the direction of increasing or decreasing in steps of 2.5% with a range from -5% to + 2 × 2.5%.

Switching the voltage from 6 kV to 10 kV is carried out in a similar way in the reverse order.

Thus, the claimed utility model allows to increase the safety level of the transformer, to exclude the possibility of a short circuit due to the complete blocking of the operation of the star winding connection circuit during operation of the “triangle” winding connection circuit and vice versa.

Claims (1)

A universal transformer, including a primary winding, a switch of the connection circuit, including two rails with fixed contacts interconnected with the winding and two rails with movable contacts interacting with them, the first of which contains a star connection circuit providing an input voltage of 10 kV, the second - connection diagram a "triangle", providing an input voltage of 6 kV, characterized in that the switch is additionally equipped with a locking device configured to provide blocking the first rail with a movable contact in the absence of voltage when selecting the operating mode of the transformer "6kV" and blocking the second rail with movable contacts in the absence of voltage when selecting the operating mode of "10kV".

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