Self-coupling phase-shifting transformer with safe switching function

Abstract

The invention 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 an iron 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 iron core comprises three central columns, and the three central columns are respectively provided with a phase modulation winding, a voltage regulation winding, a common winding and a high-voltage winding from inside to outside in sequence. When the potential of the tail end of the common winding is zero and the phase modulation on-load tap-changer is located at the rated tap-changer position, the second electric mechanism of the no-load reversing tap-changer can be operated, at the moment, it is indicated that the self-coupling phase-shifting transformer is located at the zero phase angle position, it is ensured that the no-load reversing tap-changer can conduct polarity conversion under the specific condition of the zero phase angle, and the polarity conversion efficiency is improved. And safe operation of the no-load reversing tap-changer can be protected, and safe switching is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of auto-coupling phase-shifting transformers, and more specifically, to an auto-coupling phase-shifting transformer with a safety switching function. Background Art

[0002] The single-core auto-phase-shifting transformer with no-load reversing switch mainly consists of a three-column core, a high-voltage winding, a voltage-regulating winding, a common winding, a phase-adjusting winding, a voltage-regulating on-load tap-changer, a phase-adjusting on-load tap-changer and an no-load reversing 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 tapchanger according to the tapping sequence. The outgoing line of the voltage regulating on-load tapchanger is led out as the low-voltage outgoing line. The end of the common winding is connected in series with the no-load reversing tapchanger. After the no-load reversing tapchanger, the out-of-phase phase-adjusting windings are respectively connected in series according to a certain rule. After the phase-adjusting winding, the outgoing lines of the phase-adjusting on-load tapchanger are connected together to form a star connection and lead out the neutral point.

[0004] Based on this, the above-mentioned auto-phase-shifting transformer changes the voltage amplitude of the low-voltage outgoing line and the phase angle (the phase angle is the angle value that describes the relative position or phase difference of the signal, through which the relative offset of the signal waveform and the relationship between them) compared to the high voltage by adjusting the number of turns of the voltage-regulating and phase-modulating windings connected to the circuit; and at zero phase-shifting angle, the maximum variation range of the phase angle of the low-voltage outgoing line compared to the high voltage is adjusted by the polarity conversion of the no-load reversing tap changer;

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

[0006] The present invention provides an auto-phase-shifting transformer with a safety switching function, and aims to solve the problem that the existing no-load reversing tap changer has no protection measures during polarity conversion, which may cause misoperation and affect safety switching.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an auto-coupling phase-shifting transformer with a safe switching function, the auto-coupling phase-shifting transformer comprising an iron 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 iron core comprising three central columns, the three central columns being respectively provided with a phase-regulating winding, a voltage-regulating winding, a common winding and a high-voltage winding from the inside to the outside; a potential monitoring structure is provided on the auto-coupling phase-shifting transformer, the potential monitoring structure being used to monitor the terminal potential of the common winding; an interlocking structure is provided between an electric mechanism 1 for driving the phase-regulating on-load tap changer and an electric mechanism 2 for driving the no-load reversing tap changer; when the potential monitoring structure detects that the terminal potential of the common winding is zero and the phase-regulating on-load tap changer is in the rated tapping position, the interlocking structure unlocks the electric mechanism 2 so that the electric mechanism 2 can drive the no-load reversing tap changer to perform switching operation.

[0008] In a preferred embodiment, the potential monitoring structure includes an external PT, the common winding includes an end y monitoring terminal, and a potential monitoring y bushing is provided on the y monitoring terminal, the external PT is provided on the potential monitoring y bushing, and the external PT is used to monitor the end potential of the common winding.

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

[0010] In a preferred embodiment, the end of the common winding is connected in series to the common terminal 2 of the no-load reversing tap changer, and the common terminal 1 of the no-load reversing tap changer and the common terminal 4 of the no-load reversing tap changer are both connected in series to the phase-adjusting winding.

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

[0012] In a preferred embodiment, the tapping wires of the voltage regulating winding are provided with several groups, and the tapping wires of the several groups are numbered in sequence. The tapping wires of the several groups of the voltage regulating winding are connected to the voltage regulating on-load tap changer according to the tapping numbers. By adjusting the tapping position of the voltage regulating on-load tap changer and the voltage regulating winding, the number of turns of the voltage regulating winding 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 and the phase angle compared to the high voltage are changed.

[0013] In a preferred embodiment, the phase-modulating winding has a plurality of tapping wires, and the plurality of tapping wires are numbered in sequence. The plurality of tapping wires of the phase-modulating winding are connected to the phase-modulating on-load tap changer according to the tapping numbers. By adjusting the tapping position of the phase-modulating on-load tap changer and the phase-modulating winding, the number of turns of the phase-modulating winding in the access circuit is changed, so that the voltage amplitude of the low-voltage lead-out line of the phase-modulating on-load tap changer and the phase angle relative to the high voltage are changed.

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

[0015] The beneficial effects of the present invention are:

[0016] According to the present invention, the electric mechanism 2 of the no-load reversing tap changer can be operated only when the potential at the end of the common winding is zero and the phase-adjusting on-load tap changer is in the rated tap position. At this time, it indicates that the autotransformer is in the zero phase angle position, ensuring that the no-load reversing tap changer can perform polarity conversion under the specific condition of zero phase angle, thereby protecting the safe operation of the no-load reversing tap changer and realizing safe switching. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a wiring schematic diagram of an auto-phase-shifting transformer with a safety switching function.

[0018] Figure 2 The present invention discloses a phase diagram (advanced phase angle) of an auto-phase-shifting transformer with a safe switching function.

[0019] Figure 3 The present invention discloses a phase diagram of an auto-phase-shifting transformer with a safe switching function (0 phase-shift angle).

[0020] Figure 4 The present invention discloses a phase diagram (lagging phase shift angle) of an auto-coupling phase-shifting transformer with a safe switching function.

[0021] Figure 5 This is a top view of the connection layout of an auto-phase-shifting transformer with a safe switching function according to the present invention.

[0022] Figure 6 This is a main view of the high-voltage side of an auto-phase-shifting transformer with a safe switching function according to the present invention.

[0023] Figure 7 This is a front view of the low-voltage side of an auto-phase-shifting transformer with a safety switching function according to the present invention.

[0024] The accompanying drawings are marked as follows: 1. high-voltage winding; 2. voltage-regulating winding; 3. common winding; 4. phase-adjusting winding; 5. voltage-regulating on-load tap changer; 6. phase-adjusting on-load tap changer; 7. off-load reversing 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. iron core. DETAILED DESCRIPTION

[0025] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0026] Refer to the instruction manual Figures 1 to 7 A self-coupling phase-shifting transformer with a safe switching function, the self-coupling phase-shifting transformer comprises an iron 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 reversing tap changer 7, the iron core 13 comprises three central columns, and the three central columns are respectively provided with the phase-regulating winding 4, the voltage-regulating winding 2, the common winding 3 and the high-voltage winding 1 in sequence from the inside to the outside; a potential monitoring structure is provided on the self-coupling phase-shifting transformer, and the potential monitoring structure is used to monitor the terminal potential of the common winding 3; an interlocking structure is provided between an electric mechanism 1 for driving the phase-regulating on-load tap changer 6 and an electric mechanism 2 for driving the no-load reversing 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 tapping position, the interlocking structure unlocks the electric mechanism 2, so that the electric mechanism 2 can drive the no-load reversing tap changer 7 to perform switching operation.

[0027] It should be noted that the electric mechanism 2 mainly includes an electric motor, a drive device and a mechanical device. The electric motor is used to provide power and driving force. The drive device is used to transmit the movement of the electric motor to the no-load reversing tap changer 7. The drive device is composed of a transmission shaft, a transmission gear, a chain or a belt, etc., and is used to convert the rotational motion of the electric motor into a linear or rotational mechanical motion. The mechanical device is the part connecting the electric motor and the switch, and is used to realize the switching operation of the tap. The mechanical device includes gears, connecting rods, a transmission mechanism and a tap connection mechanism. Driven by the electric motor, the mechanical device can connect the tap to different positions to increase or decrease the voltage of the transformer. Through the tap switching operation of the no-load reversing tap changer 7, the voltage regulation and power distribution of the power system are realized. The combination of the electric motor and the drive device enables the switching of the tap to be realized through remote or automatic control, thereby improving the convenience of operation and the degree of automation of the system.

[0028] Furthermore, the potential monitoring structure includes an external PT, the common winding 3 includes an end y monitoring terminal 11, and a potential monitoring y bushing is provided on the y monitoring terminal 11, the external PT is provided on the potential monitoring y bushing, and the external PT is used to monitor the end potential of the common winding 3.

[0029] It should be noted that the external PT is a device used to measure the voltage in the power system. It is usually installed on power equipment or power lines to reduce high voltage signals to a lower measurable range. The main function of the external PT is to convert high voltage signals into low voltage signals proportional to it for monitoring, measurement and protection operations. The external PT is usually used in conjunction with measuring instruments, protection devices or monitoring systems. The potential monitoring bushing is a device used to monitor the potential of the winding. It is usually installed at the end of the winding. It 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 changes of the winding can be monitored in real time, so as to detect abnormal conditions or faults in time and take corresponding measures. The external PT is used to measure voltage signals, while the potential monitoring bushing is used to provide space for installing potential monitoring equipment to monitor the potential changes of the winding. Their application in the power system is to achieve voltage measurement and potential monitoring to ensure the safe operation of the system and the protection of equipment.

[0030] Furthermore, 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] Furthermore, the end of the common winding 3 is connected in series to the common terminal 2 of the no-load reversing tap changer 7 , and the common terminal 1 of the no-load reversing tap changer 7 and the common terminal 4 of the no-load reversing tap changer 7 are both connected in series to the phase-adjusting winding 4 .

[0032] Furthermore, both the moving contact outlet terminal of the voltage-regulating on-load tap changer 5 and the moving contact outlet terminal of the phase-regulating on-load tap changer 6 are provided with low-voltage lead-out wires, and a plurality of phase-regulating on-load tap changers 6 are provided, and the low-voltage lead-out wires of the plurality of phase-regulating on-load tap changers 6 are star-connected to form a neutral point, and a bushing N is provided on the neutral point.

[0033] Furthermore, the tapping wires of the voltage regulating winding 2 are provided with several groups, and the tapping wires of the several groups are numbered in sequence. The tapping wires of the several groups of the voltage regulating winding 2 are connected to the voltage regulating on-load tap changer 5 according to the tapping numbers. By adjusting the tapping 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-out line of the voltage regulating on-load tap changer 5 and the phase angle compared with the high voltage are changed.

[0034] Furthermore, the phase-modulating winding 4 has a plurality of tapping wires, and the plurality of tapping wires are numbered in sequence. The plurality of tapping wires of the phase-modulating winding 4 are connected to the phase-modulating on-load tap changer 6 according to the tapping numbers. By adjusting the tapping positions of the phase-modulating on-load tap changer 6 and the phase-modulating winding 4, the number of turns of the phase-modulating winding 4 connected to the circuit is changed, so that the voltage amplitude of the low-voltage lead-out line of the phase-modulating on-load tap changer 6 and the phase angle relative to the high voltage are changed.

[0035] It should be noted that the plurality of connected groups of the voltage regulating winding 2 and the plurality of connected groups of the phase regulating winding 4 are tapped and numbered in the order of continuous digital numbering, percentage or voltage level.

[0036] Furthermore, a terminal K is provided on the voltage regulating winding 2 , and the end of the high voltage winding 1 , the terminal K of the voltage regulating winding 2 and the head end of the common winding 3 are connected together.

[0037] In this embodiment, the implementation scenario is specifically as follows: before the high-voltage winding 1 and the voltage regulating winding 2 are respectively connected in series to the common winding 3, the voltage regulating winding 2 is connected to the voltage regulating on-load tap changer 5 according to the tapping sequence number, and the outgoing line of the voltage regulating on-load tap changer 5 is led out as the low-voltage outgoing line, and the end of the common winding 3 is connected in series with the no-load reversing tap changer 7. After the no-load reversing tap changer 7, the phase-adjusting winding 4 with different phases is connected in series according to the design rule. After the phase-adjusting winding 4, the outgoing lines of the outgoing line end of the phase-adjusting on-load tap changer 6 are connected together to form a star connection and lead out the neutral point. By adjusting the number of turns of the voltage regulating winding 2 and the phase-adjusting winding 4 connected to the circuit, 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 set. During operation, the potential at the end of the common winding 3 is monitored in real time through an external PT. When the potential at the end of the common winding 3 is zero, the electric mechanism 2 of the no-load reversing tap changer 7 can be operated, and the neutral point is led out. Through the polarity conversion of the no-load reversing tap changer 7, the maximum variation range of the phase angle of the low-voltage outlet line compared to the high voltage is adjusted. When the motor mechanism 1 of the phase-adjusting on-load tap changer 6 is interlocked with the motor mechanism 2 of the no-load reversing tap changer 7, the motor mechanism 2 of the no-load reversing tap changer 7 can be operated only when the phase-adjusting on-load tap changer 6 is in the rated tap position at zero phase angle and the phase-adjusting winding 4 is withdrawn from the circuit. When the phase-adjusting on-load tap changer 6 is in the remaining tap positions, the motor mechanism 2 of the no-load reversing tap changer 7 cannot be operated. When the potential at the end of the common winding 3 is zero and the phase-adjusting on-load tap changer 6 is in the rated tap position, the motor mechanism 2 of the no-load reversing tap changer 7 can be operated. At this time, it indicates that the autotransformer is in the zero phase angle position, ensuring that the no-load reversing tap changer 7 can perform polarity conversion under the specific condition of zero phase angle, which can protect the safe operation of the no-load reversing tap changer 7 and achieve safe switching.

[0038] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. An auto-phase-shifting transformer with a safe switching function, characterized in that: The auto-phase-shifting transformer comprises an iron core (13), a high-voltage winding (1), a voltage-regulating winding (2), a common winding (3), a phase-modulating winding (4), a voltage-regulating on-load tap changer (5), a phase-modulating on-load tap changer (6) and an off-load reversing tap changer (7); the iron core (13) comprises three central columns, and the three central columns are respectively provided with the phase-modulating winding (4), the voltage-regulating winding (2), the common winding (3) and the high-voltage winding (1) in sequence from the inside to the outside; The auto-phase-shifting transformer is provided with a potential monitoring structure, which is used to monitor the terminal potential of the common winding (3); The phase-adjusting on-load tap changer (6) is provided with a first electric mechanism, and the off-load reversing tap changer (7) is provided with a second electric mechanism, and an interlocking structure is provided between the first electric mechanism and the second electric mechanism; When the potential monitoring structure detects that the terminal potential of the common winding (3) is zero, and the phase-modulating on-load tap changer (6) is in the rated tap position, the interlocking structure unlocks the second electric mechanism, so that the second electric mechanism can drive the off-load reversing tap changer (7) to perform switching operation; a terminal K is provided on the voltage regulating winding (2), and the end of the high-voltage winding (1), the terminal K of the voltage regulating winding (2) and the head end of the common winding (3) are connected together.

2. The auto-phase-shifting transformer with a safe switching function according to claim 1, characterized in that: The potential monitoring structure comprises an external PT, the common winding (3) comprises an end y monitoring terminal (11), and a potential monitoring y bushing is arranged on the y monitoring terminal (11), the external PT is arranged on the potential monitoring y bushing, and the external PT is used to monitor the end potential of the common winding (3).

3. The auto-phase-shifting transformer with a safe switching function according to claim 2, characterized in that: When the phase-adjusting on-load tapping switch (6) is in a rated tapping position, the phase-adjusting winding (4) is withdrawn from the circuit.

4. The auto-phase-shifting transformer with a safe switching function according to claim 3, characterized in that: The end of the common winding (3) is connected in series to the common terminal 2 of the no-load reversing tap changer (7), and the common terminal 1 of the no-load reversing tap changer (7) and the common terminal 4 of the no-load reversing tap changer (7) are both connected in series to the phase-adjusting winding (4).

5. The auto-phase-shifting transformer with a safe switching function according to claim 4, characterized in that: The moving contact outlet end of the voltage-adjusting on-load tap changer (5) and the moving contact outlet end of the phase-adjusting on-load tap changer (6) are both provided with low-voltage lead-out lines, and the phase-adjusting on-load tap changer (6) is provided with a plurality of low-voltage lead-out lines, and the plurality of low-voltage lead-out lines of the phase-adjusting on-load tap changers (6) are star-connected to form a neutral point, and a bushing N is provided on the neutral point.

6. The auto-phase-shifting transformer with a safety switching function according to claim 5, characterized in that: The tapping wires of the voltage regulating winding (2) are provided with a plurality of groups, and the plurality of groups of tapping wires are tapped and numbered in sequence. The plurality of groups of tapping wires of the voltage regulating winding (2) are connected to the voltage regulating on-load tap changer (5) according to the tapping numbers. By adjusting the tapping 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-out wire of the voltage regulating on-load tap changer (5) and the phase angle relative to the high voltage are changed.

7. The auto-phase-shifting transformer with a safety switching function according to claim 6, characterized in that: The phase-modulating winding (4) has a plurality of tapping wires, and the plurality of tapping wires are numbered in sequence. The plurality of tapping wires of the phase-modulating winding (4) are connected to the phase-modulating on-load tap changer (6) according to the tapping numbers. By adjusting the tapping positions of the phase-modulating on-load tap changer (6) and the phase-modulating winding (4), the number of turns of the phase-modulating winding (4) connected to the circuit is changed, so that the voltage amplitude of the low-voltage lead-out line of the phase-modulating on-load tap changer (6) and the phase angle relative to the high voltage are changed.

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