Winding wiring structure of step-down phase-shifting distribution transformer

Abstract

The utility model discloses a winding wiring structure of a step-down phase-shifting distribution transformer, and particularly relates to the field of transformers, the winding wiring structure of the step-down phase-shifting distribution transformer comprises a transformer and a transformer winding wiring structure, the transformer is of a three-phase structure, an iron core column is arranged in the transformer, and two phase modulation windings, an excitation winding, a voltage regulation winding and a low-voltage winding are sleeved on the iron core column; one excitation winding and one voltage regulating winding are connected in series to form a high-voltage voltage regulating unit, the three-phase high-voltage voltage regulating units are connected end to end to form triangular connection, and the triangular connection comprises three vertexes. The phase-shifting transformer is of a single-transformer-body structure, the number of windings is small, wiring is simple, compared with a multi-transformer combined structure achieving the same function, cost is low, occupied space is small, additional devices such as newly-added lines and switches are not needed, compared with a phase-shifting step-down transformer of a double-transformer-body structure, the structure is greatly simplified, design and manufacturing difficulty is lowered, and the cost is reduced. And the operation reliability of the system is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to transformer technical field more specifically, the utility model relates to a kind of winding connection structure of step-down phase-shift distribution transformer. BACKGROUND

[0002] The existing step-down transformer in distribution network only has the function of adjusting voltage, and cannot control the power flow distribution of specific line in complex distribution network. Based on this, a combination of conventional step-down transformer and phase-shifting transformer is currently adopted, so that the step-down transformer changes the phase of voltage on both sides of transmission line, thereby being able to control the power flow distribution of specific line in complex distribution network, and also having the functions of step-down of original distribution transformer and providing new function of high-voltage side loop.

[0003] However, the combination of conventional step-down transformer and phase-shifting transformer in the above prior art increases the number of transformers, resulting in more complex connection of entire power system, increased land occupation, and high cost due to increased investment in related lines and switches, as well as poor operation reliability and maintainability due to complexity of system. SUMMARY

[0004] The winding connection structure of step-down phase-shift distribution transformer provided by the utility model solves the problem that the existing combination of conventional step-down transformer and phase-shifting transformer increases the number of transformers, resulting in more complex connection of entire power system and increased land occupation.

[0005] To achieve the above object, the utility model provides the following technical scheme: a winding connection structure of step-down phase-shift distribution transformer, comprising a transformer and a transformer winding connection structure, the transformer is a three-phase structure, a core column is arranged in the transformer, two phase-modulating windings, one excitation winding, one voltage-regulating winding and one low-voltage winding are sleeved on the core column;

[0006] The excitation winding and the voltage-regulating winding are connected in series to form a high-voltage voltage-regulating unit, the three-phase high-voltage voltage-regulating unit is connected at the beginning and the end to form a triangle connection, and the triangle connection comprises three vertices.

[0007] The phase-modulating windings comprise a high-voltage side and a low-voltage side, the high-voltage side and the low-voltage side are both provided with voltage-regulating switches, and the three vertices are connected with the three-phase phase-modulating windings, respectively.

[0008] The low-voltage winding comprises phase a, phase b, phase c and zero phase, and the low-voltage side of the three-phase phase-modulating windings is connected with the connection terminals of the three-phase low-voltage windings, respectively.

[0009] In a preferred embodiment, the low-voltage windings of the three-phase are connected in star.

[0010] In a preferred embodiment, the transformer is supplied with high voltage on both sides, and the connection between the high and low voltage is Dy connection, Dy representing Delta-Y connection.

[0011] In a preferred embodiment, the clock sequence number between the high voltage side and the low voltage side of the transformer is consistent with the commonly used number of ordinary distribution transformer.

[0012] In a preferred embodiment, the connection between the two sides of the transformer is an angularly connected symmetrical phase shifting structure.

[0013] In a preferred embodiment, a phase modulation switch is installed on the high voltage side of the phase modulation winding, and the phase modulation switch is used to change the phase difference between the two sides.

[0014] The beneficial effects of the present application are as follows:

[0015] 1. The winding connection structure of the step-down phase-shifting distribution transformer provided by the present application has a single body structure, a small number of windings, and simple connection, and has lower cost, smaller footprint, no additional lines and switches, and other additional devices compared to a multi-transformer combined structure with the same function, and the phase-shifting step-down transformer structure is greatly simplified compared to a double-body structure, thereby reducing design and manufacturing difficulty and improving system operation reliability.

[0016] 2. The winding connection structure of the step-down phase-shifting distribution transformer provided by the present application realizes the phase-shifting function between the two sides of the power supply and the step-down function between the power supply side and the load side by adding a phase modulation winding and a switch to the step-down distribution transformer connection structure with Dy connection between the high and low voltage connection groups and adopting a special connection method. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 The present application is a winding connection schematic diagram.

[0018] Fig. 2 The present application is a voltage vector schematic diagram of each line end.

[0019] Fig. 3 The present application is a current vector schematic diagram of each line end.

[0020] The reference signs are: 1, phase modulation winding; 2, excitation winding; 3, voltage regulation winding; 4, low voltage winding. DETAILED DESCRIPTION

[0021] The present application will be further described in detail below with reference to the accompanying drawings, and it is necessary to point out here that the following specific embodiments are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application, and those skilled in the art can make some non-essential improvements and adjustments to the present application according to the above application content.

[0022] With reference to the drawings accompanying the specification Figs. 1-3 A winding connection structure of a step-down phase-shifting distribution transformer, comprising a transformer and a transformer winding connection structure, the transformer being of a three-phase structure, a core column being arranged in the transformer, and two phase-shifting windings 1, an excitation winding 2, a voltage-regulating winding 3, and a low-voltage winding 4 being sleeved on the core column; the excitation winding 2 and the voltage-regulating winding 3 are connected in series to form a high-voltage voltage-regulating unit, the three-phase high-voltage voltage-regulating units are connected in series to form a triangle connection, and the triangle connection comprises three vertices; the phase-shifting windings 1 comprise a high-voltage side and a low-voltage side, the high-voltage side and the low-voltage side are both provided with voltage-regulating switches, and the three vertices are connected with the three-phase phase-shifting windings 1, respectively; the low-voltage winding 4 comprises a-phase, b-phase, c-phase, and zero-phase, and the low-voltage sides of the three-phase phase-shifting windings 1 are connected with the connection terminals of the three-phase low-voltage winding 4, respectively.

[0023] The implementation scenario is specifically as follows: the transformer is of a three-phase structure, and each phase has five windings, namely two phase-shifting windings 1, an excitation winding 2, a voltage-regulating winding 3, and a low-voltage winding 4, and the three phases have fifteen windings in total, the excitation winding 2 of each phase and the voltage-regulating winding 3 of the phase are connected in series to form a high-voltage voltage-regulating unit of the phase, and this connection mode can realize the regulation and stability of the high-voltage side voltage. The excitation winding 2 provides excitation current, and the voltage-regulating winding 3 controls the voltage of the high-voltage side by adjusting the turn ratio of the winding, and the three-phase three-group high-voltage voltage-regulating units are connected in series to form a triangle, and the triangle connection forms a triangle loop, and this connection mode can realize the balance and stability of the high-voltage side voltage. The connection of the triangle loop forms a low-impedance power path, so that the high-voltage side voltage is evenly distributed among the phases, the vertices of the triangle connection of each phase are connected with two out-of-phase phase-shifting windings 1, respectively, and the two out-of-phase phase-shifting windings 1 are connected at the vertices of the triangle loop. This connection mode can realize the phase regulation of the high-voltage side voltage. The phase-shifting windings 1 change the phase difference of the high-voltage side voltage by adjusting the turn ratio and relative position of the windings to realize phase regulation and control, and the two phase-shifting windings 1 of each phase are respectively provided with two phase-shifting switches, and the phase-shifting switches are used to change the phase difference between the two sides. By adjusting the state of the phase-shifting switch, the phase difference of the high-voltage side voltage can be adjusted and controlled, and three line terminals are led out to connect with two high-voltage sides of the three-phase S1, S2, S3, and another high-voltage side of the three-phase L1, L2, L3. The low-voltage winding 4 of the three-phase is of a conventional star connection, and three line terminals are led out to connect with a, b, c three-phase, respectively, and a neutral point line terminal is led out to connect with 0 phase, and by connecting the neutral point line terminal to 0 phase, the grounding point can be provided, the three-phase load can be balanced, and the zero-sequence current path can be provided, so as to improve the safety, stability, and reliability of the power system.

[0024] With reference to the drawings accompanying the specification Figs. 1-3 The low-voltage winding 4 of the three-phase is of a star connection.

[0025] It should be noted that in the star connection, the end points of the three low-voltage windings 4 are connected together through the neutral point, which can provide a shared neutral point that can be used to connect the ground or guide the zero-sequence current, thereby achieving current balance and symmetry. The neutral point can be connected to the ground, and the voltage to the ground can be reduced through grounding, which is very important for reducing the voltage amplitude to the ground and reducing the impact of ground faults.

[0026] Referring to the drawings accompanying the specification Figs. 1-3 , the transformer is powered by two sides of high voltage, and the connection mode between high voltage and low voltage is Dy connection, Dy represents Delta-Y connection.

[0027] It should be noted that Dy connection can reduce harmonic voltage, reduce the flow of zero-sequence current and improve the reliability of the system in three-phase transformers.

[0028] Referring to the drawings accompanying the specification Figs. 1-3 , the clock sequence number between the high voltage side and the low voltage side of the transformer is consistent with the commonly used label of ordinary distribution transformers.

[0029] It should be noted that when the clock sequence number between high voltage and low voltage is consistent with that of ordinary distribution transformers, it can be convenient for design, installation and operation and maintenance, and it can directly select a transformer with the same label for replacement, or add a new transformer compatible with the existing system without additional adjustment or re-labeling.

[0030] Referring to the drawings accompanying the specification Figs. 1-3 , the two phase modulation windings 1 are connected to two phase modulation switches respectively.

[0031] It should be noted that by connecting the two phase modulation windings 1 to the two phase modulation switches, the phase difference of each phase can be independently adjusted. This makes it possible to more flexibly control the voltage waveform and phase angle of each phase in a three-phase system. Independent phase adjustment is very useful for achieving accurate power factor correction, power quality improvement and power system stability. Connecting the phase modulation windings 1 to the phase modulation switches respectively can achieve phase adjustment isolation. In this way, when the phase difference of a certain phase needs to be adjusted, it will not interfere with other phases. This interference isolation design can effectively ensure the stability and reliability of the system.

[0032] Referring to the drawings accompanying the specification Figs. 1-3 , the phase modulation winding 1 is connected to the voltage regulation switch, which is used to change the voltage transformation ratio and adjust the amplitude of the voltage without changing the phase angle difference between high voltage and low voltage.

[0033] It should be noted that by adjusting the voltage regulating switch, the voltage ratio and amplitude can be accurately controlled. This is very useful for meeting different load requirements, power grid regulation and power system stability, etc. By adjusting the voltage amplitude, the load change can be adapted and the normal operation of the equipment can be ensured. Since the voltage regulating switch only changes the amplitude of the voltage without changing the phase angle difference, this connection can keep the phase angle difference between high and low voltage unchanged. In the power system, the phase angle difference is very important for maintaining the stability and correct operation of the power grid. By keeping the phase angle difference unchanged, it can avoid causing the power grid to be unstable or other problems. In the power system, when changing the voltage ratio and regulating the voltage, if the phase angle difference is also changed, it may have adverse effects on other equipment and systems. By connecting the phase regulating winding 1 to the voltage regulating switch, the voltage amplitude can be independently controlled without affecting the phase angle difference, thereby reducing unnecessary interference to other equipment and systems.

[0034] Referring to the drawings accompanying the specification Figs. 1-3 The connection between the two sides of the transformer is an angularly connected symmetrical phase-shifting structure.

[0035] It should be noted that the transformer connection mode of the angularly connected symmetrical phase-shifting structure can realize the advantages of wide phase adjustment range, uniform current distribution, and power control and regulation, providing greater flexibility and stability for the operation and management of the power system.

[0036] Referring to the drawings accompanying the specification Figs. 1-3 The high-voltage side of the phase regulating winding 1 is provided with a phase regulating switch, the connection between the two sides of the high-voltage is an angularly connected symmetrical phase-shifting structure, and the phase regulating switch is used to change the phase difference between the two sides of the voltage.

[0037] It should be noted that by adjusting the phase regulating switch, the phase difference between the two sides of the high-voltage can be changed, i.e. the phase angle of the voltage waveform is adjusted. This is very important for the operation and control of the power system. The adjustment of the phase difference can realize power factor correction, power quality improvement and power grid stability improvement in the power system; by adjusting the phase difference, the direction and size of the power flow in the power system can be controlled. In a complex power system, the power flow needs to be adjusted according to the load demand and system operation state to maintain the balance and stability of the system. The application of the phase regulating switch can realize flexible power flow control and adjust the relative power flow direction between each node in the power system.

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

Claims

1. A winding connection structure of a step-down phase-shifting distribution transformer, characterized by, It includes: The transformer and the transformer winding structure, the transformer is three-phase structure, the transformer is provided with core column, the core column is provided with two phase modulation winding (1), one excitation winding (2), one voltage regulation winding (3) and one low voltage winding (4); One excitation winding (2) and one voltage regulation winding (3) are connected in series to form a high-voltage voltage regulation unit, and three-phase high-voltage voltage regulation units are connected in series to form a triangle connection, which includes three vertices; The phase modulation winding (1) includes high-voltage side and low-voltage side, and the high-voltage side and the low-voltage side are provided with voltage regulation switch, and the three vertices are connected with three-phase phase modulation winding (1) respectively; The low voltage winding (4) includes a phase, b phase, c phase and zero phase, and the low voltage side of the three-phase phase modulation winding (1) is connected with the connection end of the three-phase low voltage winding (4) respectively.

2. A winding connection structure of a step-down phase-shifting distribution transformer according to claim 1, characterized in that: The transformer is powered by two sides of high voltage, and the connection mode between high voltage and low voltage is Dy connection, Dy represents Delta-Y connection.

3. A winding connection structure of a step-down phase-shifting distribution transformer according to claim 2, characterized in that: The clock sequence number between the high voltage side and the low voltage side of the transformer is consistent with the label of the distribution transformer.

4. A winding connection structure of a step-down phase-shifting distribution transformer according to claim 3, characterized in that: The connection between the two sides of the transformer is an angularly connected symmetrical phase shift structure.

5. A winding connection structure of a step-down phase-shifting distribution transformer according to claim 4, characterized in that: The high voltage side of the phase modulation winding (1) is provided with a phase modulation switch, and the phase modulation switch is used to change the phase difference between the two sides of the voltage.

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