Self-coupled phase-shifting transformer with safe switching function

Abstract

The application discloses a self-coupling phase-shifting transformer with a safe switching function, and particularly relates to the field of self-coupling phase-shifting transformers. The self-coupling phase-shifting transformer comprises a core, a high-voltage winding, a voltage-regulating winding, a common winding, a phase-modulating winding, a voltage-regulating load-connected tap changer, a phase-modulating load-connected tap changer and a no-load commutating tap changer. The core comprises three center columns, which are sequentially provided with the phase-modulating winding, the voltage-regulating winding, the common winding and the high-voltage winding from inside to outside. The application can only operate the electric mechanism two of the no-load commutating tap changer when the end potential of the common winding is zero and the phase-modulating load-connected tap changer is in a rated tap position, which indicates that the self-coupling phase-shifting transformer is in a zero phase angle position, ensures that the no-load commutating tap changer can perform polarity conversion under the specific condition of the zero phase angle, protects safe operation of the no-load commutating tap changer and realizes safe switching.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of self-coupling phase-shifting transformer, more particularly, the present application relates to a self-coupling phase-shifting transformer with safe switching function. BACKGROUND

[0002] The single-core self-coupling phase-shifting transformer with no-load commutation switch mainly comprises a three-column core, a high-voltage winding, a voltage-regulating winding, a common winding, a phase-regulating winding, a voltage-regulating on-load tap changer, a phase-regulating on-load tap changer and a no-load commutation tap changer.

[0003] The high-voltage winding and the voltage-regulating winding are respectively connected in series before the common winding, the voltage-regulating winding is connected to the voltage-regulating on-load tap changer according to the tap sequence number, the voltage-regulating on-load tap changer is connected to the low-voltage outlet, the common winding is connected in series with the no-load commutation tap changer at the end, the no-load commutation tap changer is connected in series with the out-of-phase phase-regulating winding according to a certain rule, the phase-regulating winding is connected together through the phase-regulating on-load tap changer outlet end, and the star connection is connected to the neutral point.

[0004] Based on this, the self-coupling phase-shifting transformer adjusts the number of turns of the voltage-regulating winding and the phase-regulating winding in the circuit to change the voltage amplitude of the low-voltage outlet and the phase angle of the high-voltage (the phase angle is an angle value describing the relative position or phase difference of the signal, through which the relative shift of the signal waveform and the relationship between them can be understood); and the polarity conversion of the no-load commutation tap changer is used to adjust the maximum change range of the phase angle of the low-voltage outlet relative to the high-voltage at zero phase angle.

[0005] Since the polarity conversion of the no-load commutation tap changer can only be operated under the specific condition of zero phase angle (zero phase angle refers to the case where the phase difference of the voltage and current waveforms is zero, that is, they pass through the zero point at the same time. In this case, polarity conversion can minimize the impact on the power system and avoid excessive current and voltage fluctuations), in order to prevent misoperation and realize safe switching of the polarity conversion of the no-load commutation tap changer, protective measures need to be taken. SUMMARY

[0006] The self-coupling phase-shifting transformer with safe switching function provided by the present application solves the problem that the existing no-load commutation tap changer has no protective measures during polarity conversion and may misoperate, affecting safe switching.

[0007] To achieve the above object, the application provides the following technical scheme: a self-coupling phase-shifting transformer with a safe switching function, which comprises a core, a high-voltage winding, a voltage-regulating winding, a common winding, a phase-regulating winding, a voltage-regulating on-load tap changer, a phase-regulating on-load tap changer and a no-load reversing tap changer, the core comprises three center columns, and the three center columns are sequentially provided from inside to outside with the phase-regulating winding, the voltage-regulating winding, the common winding and the high-voltage winding; a potential monitoring structure is arranged on the self-coupling phase-shifting transformer, and the potential monitoring structure is used for monitoring the terminal potential of the common winding; an interlocking structure is arranged between an electric mechanism one for driving the phase-regulating on-load tap changer and an electric mechanism two for driving the no-load reversing tap changer; when the terminal potential of the common winding detected by the potential monitoring structure is zero and the phase-regulating on-load tap changer is in a rated tap position, the interlocking structure unlocks the electric mechanism two, so that the electric mechanism two can drive the no-load reversing tap changer to work.

[0008] In a preferred embodiment, the potential monitoring structure comprises an external PT, the common winding comprises a terminal y monitoring terminal, a potential monitoring y bushing is arranged on the y monitoring terminal, and the external PT is arranged on the potential monitoring y bushing, and the external PT is used for monitoring the terminal potential of the common winding.

[0009] In a preferred embodiment, when the phase-regulating on-load tap changer is in the rated tap position, the phase-regulating winding is withdrawn from the circuit.

[0010] In a preferred embodiment, the terminal of the common winding is connected in series with a common terminal two of the no-load reversing tap changer, and a common terminal one of the no-load reversing tap changer and a common terminal four of the no-load reversing tap changer are both connected in series with the phase-regulating winding.

[0011] In a preferred embodiment, the moving contact outlet end of the voltage-regulating on-load tap changer and the moving contact outlet end of the phase-regulating on-load tap changer are both provided with a low-voltage lead-out wire, the phase-regulating on-load tap changer is provided with a plurality of phase-regulating on-load tap changers, the low-voltage lead-out wires of the plurality of phase-regulating on-load tap changers are star-connected and form a neutral point, and a bushing N is arranged on the neutral point.

[0012] In a preferred embodiment, the tap lines of the voltage-regulating winding are provided with a plurality of groups, the plurality of groups of tap lines are sequentially numbered, the plurality of groups of tap lines of the voltage-regulating winding are connected to the voltage-regulating on-load tap changer according to the tap numbers, the number of turns of the voltage-regulating winding in the circuit is changed by adjusting the tap positions of the voltage-regulating on-load tap changer and the voltage-regulating winding, and the voltage amplitude of the low-voltage lead-out wire of the voltage-regulating on-load tap changer and the phase angle compared with the high voltage are changed.

[0013] In a preferred embodiment, the tap lines of the phase-modulating winding are provided with several groups, and the several groups of tap lines are sequentially numbered, and the several groups of tap lines of the phase-modulating winding are connected to the phase-modulating on-load tap changer according to the tap numbers, and by adjusting the tap positions of the phase-modulating on-load tap changer and the phase-modulating winding, the number of turns of the phase-modulating winding in the circuit is changed, so that the voltage amplitude of the low-voltage outgoing line of the phase-modulating on-load tap changer and the phase angle compared with the high voltage are changed.

[0014] In a preferred embodiment, a terminal K is arranged on the voltage-regulating winding, and the end of the high-voltage winding, the terminal K of the voltage-regulating winding and the start of the common winding are connected together.

[0015] The present application has the following beneficial effects:

[0016] The present application can ensure that the no-load commutating tap changer can perform polarity conversion under the specific condition of zero phase angle, protect the safe operation of the no-load commutating tap changer, and realize safe switching when the end potential of the common winding is zero and the phase-modulating on-load tap changer is at the rated tap position. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The present application is a wiring principle diagram of a self-coupled phase-shifting transformer with safe switching function.

[0018] Figure 2 The present application is a phasor diagram (leading phase-shifting angle) of a self-coupled phase-shifting transformer with safe switching function.

[0019] Figure 3 The present application is a phasor diagram (0 phase-shifting angle) of a self-coupled phase-shifting transformer with safe switching function.

[0020] Figure 4 The present application is a phasor diagram (lagging phase-shifting angle) of a self-coupled phase-shifting transformer with safe switching function.

[0021] Figure 5 The present application is a wiring layout diagram of a self-coupled phase-shifting transformer with safe switching function.

[0022] Figure 6 The present application is a high-voltage side layout diagram of a self-coupled phase-shifting transformer with safe switching function.

[0023] Figure 7 The present application is a low-voltage side layout diagram of a self-coupled phase-shifting transformer with safe switching function.

[0024] The reference signs are: 1, high-voltage winding; 2, voltage regulating winding; 3, common winding; 4, phase regulating winding; 5, voltage regulating on-load tap changer; 6, phase regulating on-load tap changer; 7, no-load switching tap changer; 8, high-voltage side terminal; 9, low-voltage side terminal; 10, neutral point terminal; 11, y monitoring terminal; 12, built-in zinc oxide arrester; 13, core. DETAILED DESCRIPTION

[0025] The following detailed description of the application is made with reference to the accompanying drawings, it is necessary to point out here that the following detailed description is only used to further illustrate the application, and cannot be understood as limiting the scope of protection of the application, and those skilled in the art can make some non-essential improvements and adjustments to the application according to the above application content.

[0026] Referring to the drawings accompanying the specification Figures 1 to 7 A self-coupling phase-shifting transformer with a safe switching function, the self-coupling phase-shifting transformer includes a core 13, a high-voltage winding 1, a voltage regulating winding 2, a common winding 3, a phase regulating winding 4, a voltage regulating on-load tap changer 5, a phase regulating on-load tap changer 6 and a no-load switching tap changer 7, the core 13 includes three center columns, the three center columns are sequentially provided from inside to outside with the phase regulating winding 4, the voltage regulating winding 2, the common winding 3, the high-voltage winding 1; The self-coupling phase-shifting transformer is provided with a potential monitoring structure, which is used for monitoring the terminal potential of the common winding 3; An interlocking structure is arranged between an electric mechanism one for driving the phase regulating on-load tap changer 6 and an electric mechanism two for driving the no-load switching tap changer 7; When the potential monitoring structure detects that the terminal potential of the common winding 3 is zero, and the phase regulating on-load tap changer 6 is in the rated tap position, the interlocking structure unlocks the electric mechanism two, so that the electric mechanism two can drive the no-load switching tap changer 7 to work.

[0027] It should be noted that the electric mechanism two mainly includes a motor, a driving device and a mechanical device, the motor is used for providing power and driving force, the driving device is used for transmitting the movement of the motor to the no-load switching tap changer 7, the driving device is composed of a transmission shaft, a transmission gear, a chain or a belt, etc., which is used for converting the rotary movement of the motor into linear or rotary mechanical movement, the mechanical device is the part connecting the motor and the switch, which is used to realize the switching operation of the tap, the mechanical device includes gears, connecting rods, transmission mechanisms and tap connecting mechanisms, under the driving of the motor, the mechanical device can connect the tap to different positions, so as to increase or decrease the voltage of the transformer, through the tap switching operation of the no-load switching tap changer 7, so as to realize the voltage regulation and power distribution of the power system, the combination of the motor and the driving device makes the switching of the tap can be realized by remote or automatic control, which improves the convenience of operation and the automation degree of the system.

[0028] Further, the potential monitoring structure comprises an external PT, the common winding 3 comprises a terminal y monitoring terminal 11, and a potential monitoring y bushing is arranged on the y monitoring terminal 11, and the external PT is arranged on the potential monitoring y bushing, and the external PT is used for monitoring the terminal potential of the common winding 3.

[0029] It should be noted that the external PT is a device used for measuring voltage in a power system, which is usually installed on a power device or a power line, and is used to reduce a high voltage signal to a lower measurable range, and the main function of the external PT is to convert a high voltage signal into a low voltage signal proportional to it, so as to perform monitoring, measurement and protection operations, and the external PT is usually used in cooperation with devices such as measuring instruments, protection devices or monitoring systems. The potential monitoring bushing is a device used for monitoring the potential of the winding, which is usually installed at the end of the winding, and provides a closed space for installing potential monitoring equipment to monitor the voltage or potential of the winding. Through the potential monitoring bushing, the potential change of the winding can be monitored in real time, so as to timely discover abnormal conditions or faults and take corresponding measures. The external PT is used for measuring the voltage signal, and the potential monitoring bushing is used to provide a space for installing the potential monitoring equipment to monitor the potential change of the winding. Their application in the power system aims to realize voltage measurement and potential monitoring to ensure the safe operation of the system and the protection of the equipment.

[0030] Further, when the phase-modulating on-load tap changer 6 is in the rated tap position, the phase-modulating winding 4 is withdrawn from the circuit.

[0031] Further, the terminal of the common winding 3 is connected in series with the common terminal two of the no-load tap changer 7, and the common terminal one of the no-load tap changer 7 and the common terminal four of the no-load tap changer 7 are both connected in series with the phase-modulating winding 4.

[0032] Further, the movable contact outlet of the voltage-regulating on-load tap changer 5 and the movable contact outlet of the phase-modulating on-load tap changer 6 are both provided with low-voltage lead-out lines, and the phase-modulating on-load tap changer 6 is provided with a plurality of phase-modulating on-load tap changers 6, the low-voltage lead-out lines of the plurality of phase-modulating on-load tap changers 6 are connected in star connection, and a neutral point is formed, and a bushing N is arranged on the neutral point.

[0033] Further, the tap lines of the voltage-regulating winding 2 are provided with a plurality of groups, and the plurality of groups of tap lines are sequentially numbered, and the plurality of groups of tap lines of the voltage-regulating winding 2 are connected to the voltage-regulating on-load tap changer 5 according to the tap numbers, and by adjusting the tap positions of the voltage-regulating on-load tap changer 5 and the voltage-regulating winding 2, the number of turns of the voltage-regulating winding 2 connected to the circuit is changed, so that the voltage amplitude of the low-voltage lead-out line of the voltage-regulating on-load tap changer 5 and the phase angle compared with the high voltage are changed.

[0034] Further, the tap lines of the phase-modulation winding 4 are provided with several groups, and the several groups of tap lines are numbered in sequence. The several groups of tap lines of the phase-modulation winding 4 are connected to the phase-modulation on-load tap changer 6 according to the tap numbers. By adjusting the tap positions of the phase-modulation on-load tap changer 6 and the phase-modulation winding 4, the number of turns of the phase-modulation winding 4 in the circuit is changed, so that the voltage amplitude of the low-voltage outgoing line of the phase-modulation on-load tap changer 6 and the phase angle compared with the high voltage are changed.

[0035] It should be noted that the several groups of tap lines of the voltage-regulation winding 2 and the several groups of tap lines of the phase-modulation winding 4 are numbered in sequence according to one of the following: continuous numbers, percentages, or voltage levels.

[0036] Further, the voltage-regulation winding 2 is provided with a terminal K, and the end of the high-voltage winding 1, the terminal K of the voltage-regulation winding 2, and the start of the common winding 3 are connected together.

[0037] In the embodiment, the implementation scenario is as follows: Before the high-voltage winding 1 and the voltage-regulation winding 2 are respectively connected in series on the common winding 3, the voltage-regulation winding 2 is connected to the voltage-regulation on-load tap changer 5 according to the tap sequence number, the outgoing line of the voltage-regulation on-load tap changer 5 is taken as the low-voltage outgoing line, the end of the common winding 3 is connected in series with the no-load commutation tap changer 7, the phase-modulation winding 4 is connected in series according to the design rule after the no-load commutation tap changer 7, the outgoing lines of the phase-modulation winding 4 are connected together through the outgoing line end of the phase-modulation on-load tap changer 6, a star connection is formed and a neutral point is led out, the number of turns of the voltage-regulation winding 2 and the phase-modulation winding 4 in the circuit is adjusted, so that the voltage amplitude of the low-voltage outgoing line and the phase angle compared with the high voltage are changed, a terminal y is led out at the end of the common winding 3, and a potential monitoring bushing is arranged, the potential at the end of the common winding 3 is monitored in real time by an external PT during operation, when the potential at the end of the common winding 3 is zero, the electric mechanism two of the no-load commutation tap changer 7 can be operated, the maximum change range of the phase angle of the low-voltage outgoing line compared with the high voltage is adjusted through the polarity conversion of the no-load commutation tap changer 7, when the electric mechanism one of the phase-modulation on-load tap changer 6 and the electric mechanism two of the no-load commutation tap changer 7 are interlocked and linked, only when the phase angle is zero, that is, the phase-modulation on-load tap changer 6 is in the rated tap position, the phase-modulation winding 4 is removed from the circuit at this time, the electric mechanism two of the no-load commutation tap changer 7 can be operated, when the phase-modulation on-load tap changer 6 is in the remaining tap positions, the electric mechanism two of the no-load commutation tap changer 7 cannot be operated, when the potential at the end of the common winding 3 is zero and the phase-modulation on-load tap changer 6 is in the rated tap position, the electric mechanism two of the no-load commutation tap changer 7 can be operated, at this time, it is indicated that the autotransformer phase-modulation transformer is in the zero phase angle position, it is ensured that the no-load commutation tap changer 7 can perform polarity conversion under the specific condition of the zero phase angle, the safe operation of the no-load commutation tap changer 7 is protected, and safe switching is realized.

[0038] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are within the protection scope of the present application.

Claims

1. An autotransformer with a safe switching function, characterized in that, The autotransformer includes a core (13), a high-voltage winding (1), a voltage regulating winding (2), a common winding (3), a phase-shifting winding (4), a voltage regulating on-load tap changer (5), a phase-shifting on-load tap changer (6), and an off-load commutation tap changer (7). The core (13) includes three central columns, and the three central columns are respectively provided with a phase-shifting winding (4), a voltage regulating winding (2), a common winding (3), and a high-voltage winding (1) from the inside to the outside. The autotransformer is equipped with a potential monitoring structure, which is used to monitor the end potential of the common winding (3). The on-load tap changer (6) is equipped with an electric mechanism one, and the off-load reversing tap changer (7) is equipped with an electric mechanism two. An interlocking structure is provided between the electric mechanism one and the electric mechanism two. When the potential monitoring structure detects that the end potential of the common winding (3) is zero, and the phase-adjusting on-load tap changer (6) is in the rated tap position, the interlocking structure unlocks the electric mechanism two, so that the electric mechanism two can drive the no-load reversing tap changer (7) to perform switching operation; the voltage regulating winding (2) is provided with terminal K, and the end of the high voltage winding (1), the terminal K of the voltage regulating winding (2) and the beginning of the common winding (3) are connected together.

2. The autotransformer with safe switching function according to claim 1, characterized in that: The potential monitoring structure includes an external PT, the common winding (3) includes an end y monitoring terminal (11), and a potential monitoring y sleeve is provided on the y monitoring terminal (11). The external PT is provided on the potential monitoring y sleeve, and the external PT is used to monitor the end potential of the common winding (3).

3. An autotransformer with a safe switching function according to claim 2, characterized in that: When the phase-adjusting on-load tap changer (6) is in the rated tap position, the phase-adjusting winding (4) is disconnected from the circuit.

4. An autotransformer with a safe switching function according to claim 3, characterized in that: The end of the common winding (3) is connected in series with the common terminal of the no-load reversing tap changer (7), and the common terminal of the no-load reversing tap changer (7) and the common terminal of the no-load reversing tap changer (7) are both connected in series with the phase-adjusting winding (4).

5. An autotransformer with a safe switching function according to claim 4, characterized in that: Both the moving contact output terminal of the voltage regulating on-load tap changer (5) and the moving contact output terminal of the phase regulating on-load tap changer (6) are provided with low-voltage leads. There are several phase regulating on-load tap changers (6). The low-voltage leads of the several phase regulating on-load tap changers (6) are connected in a star configuration to form a neutral point, and a bushing N is provided on the neutral point.

6. An autotransformer with a safe switching function according to claim 5, characterized in that: The taps of the voltage regulating winding (2) are provided in several groups, and the taps of the several groups are numbered in sequence. The taps of the several groups of the voltage regulating winding (2) are connected to the voltage regulating on-load tap changer (5) according to the tap numbers. By adjusting the tap position of the voltage regulating on-load tap changer (5) and the voltage regulating winding (2), the number of turns of the voltage regulating winding (2) connected to the circuit is changed, so that the voltage amplitude of the low voltage lead of the voltage regulating on-load tap changer (5) changes with the phase angle compared with the high voltage.

7. An autotransformer with a safe switching function according to claim 6, characterized in that: The phase-adjusting winding (4) has several sets of taps, and the taps of the several sets of taps are numbered in sequence. The several sets of taps of the phase-adjusting winding (4) are connected to the phase-adjusting on-load tap changer (6) according to the tap numbers. By adjusting the tap position of the phase-adjusting on-load tap changer (6) and the phase-adjusting winding (4), the number of turns of the phase-adjusting winding (4) connected to the circuit is changed, so that the voltage amplitude of the low-voltage lead of the phase-adjusting on-load tap changer (6) and the phase angle compared with the high voltage are changed.

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