Capacity increasing device for power distribution area

Abstract

The utility model relates to the technical field of power distribution transformer areas, in particular to a power distribution transformer area capacity increasing device, which comprises a capacity increasing transformer, a power distribution transformer area capacity increasing transformer, a power distribution transformer area capacity increasing transformer and a power distribution transformer area capacity increasing transformer, the first capacity-increasing switch and the second capacity-increasing switch are both connected with the capacity-increasing transformer in series, the first capacity-increasing switch and the second capacity-increasing switch are turned on or turned off at the same time, the first capacity-increasing switch is arranged between the high-voltage side of the capacity-increasing transformer and the power taking device, and the second capacity-increasing switch is arranged between the high-voltage side of the capacity-increasing transformer and the power taking device. The second capacity-increasing switch is arranged on the low-voltage side of the capacity-increasing transformer. According to the utility model, the distribution transformer and the capacity-increasing transformer are respectively controlled to be connected into or connected out of the circuit through the switch, the two transformers work simultaneously when the output of the power grid is relatively large, and one transformer works when the output of the power grid is relatively small, so that the service life of the transformers is prolonged, and the load upper limit of a power distribution area is increased.

Description

Technical Field

[0001] The utility model relates to the technical field of distribution substations. Specifically, the utility model relates to a capacity increasing device for a distribution substation. Background Art

[0002] With the continuous maturity of photovoltaic power generation technology and cost reduction, as well as the increasing demand for renewable energy, photovoltaic power generation equipment has been gradually popularized in distributed places such as buildings, industrial plants, and residential areas. At the same time, as more and more photovoltaic power generation equipment converts solar energy into electrical energy and injects it into the power grid, the photovoltaic power in some areas exceeds the bearing capacity of the power grid. When the power transmission volume of the photovoltaic power generation equipment to the power grid is large (for example, on sunny days), it may cause a large load on the transformer, thus affecting the safety and use of the transformer and the power grid. According to statistics, at present, there are tens of thousands of distribution transformers in Henan Province alone that have reverse heavy overloads, seriously affecting the healthy operation of the power grid.

[0003] The existing methods for increasing the capacity of a distribution substation usually involve adding a new distribution substation or replacing the transformer with a larger capacity to adapt to the load growth. However, if the power transmission volume of the photovoltaic power generation equipment to the power grid is small (for example, on cloudy and rainy days), resulting in a small load on the distribution substation, the operating efficiency of the transformer in the larger capacity transformer is low, which will cause waste of resources and affect the service life of the transformer. And adding a distribution substation requires sufficient space to accommodate the equipment, and the transformer needs to be installed on the electric pole through a bracket, with a relatively high economic cost. Summary of the Utility Model

[0004] To solve the above technical problem that when increasing the capacity of a transformer in the prior art, it may lead to a low operating efficiency of a larger capacity transformer, resulting in waste of resources and affecting the service life of the transformer, the utility model proposes a capacity increasing device for a distribution substation.

[0005] A capacity-increasing device for a distribution substation area, comprising: a capacity-increasing transformer A2, whose high-voltage side is connected to the power grid, the capacity-increasing transformer A2 converts the received high-voltage electricity into low-voltage electricity, and the low-voltage side of the capacity-increasing transformer A2 outputs electric energy to at least one electrical branch; a power-taking device, connected in series with the capacity-increasing transformer A2, the power-taking device is arranged on the high-voltage side of the capacity-increasing transformer A2; the power-taking device comprises a series-connected power-taking coil and a capacitor, one end of the primary-side coil of the power-taking coil is connected to the line of the high-voltage side of the capacity-increasing transformer A2 through the capacitor, and the other end of the primary-side coil is grounded; a first capacity-increasing switch K21 and a second capacity-increasing switch K22, the first capacity-increasing switch K21 and the second capacity-increasing switch K22 are both connected in series with the capacity-increasing transformer A2, and the first capacity-increasing switch K21 and the second capacity-increasing switch K22 are opened or closed simultaneously, the first capacity-increasing switch K21 is arranged between the high-voltage side of the capacity-increasing transformer A2 and the power-taking device, and the second capacity-increasing switch K22 is arranged on the low-voltage side of the capacity-increasing transformer A2.

[0006] In one embodiment, a capacity-increasing device for a distribution substation area further comprises: a distribution transformer A1 and a distribution switch K1, the distribution transformer A1 is connected in parallel with the capacity-increasing transformer A2, wherein, the high-voltage sides of the distribution transformer A1 and the capacity-increasing transformer A2 are both connected to the power grid, and the low-voltage side of the distribution transformer A1 outputs electric energy to a plurality of electrical branches; the distribution switch K1 is connected in series with the distribution transformer A1, the distribution switch K1 is arranged on the high-voltage side of the capacity-increasing transformer A2, wherein, the distribution transformer A1 and the capacity-increasing transformer A2 are installed in the same distribution area.

[0007] In one embodiment, a first current transformer L1 is further configured on the high-voltage side of the capacity-increasing transformer A2.

[0008] In one embodiment, the high-voltage side of the capacity-increasing transformer A2 is connected to the upstream power grid line through a first fuse FU1; the first fuse FU1 is a drop-out fuse.

[0009] In one embodiment, the downstream of the first fuse FU1 is grounded through the first lightning arrester FB1.

[0010] In one embodiment, a capacity-increasing device for a distribution substation area further comprises: a compensation branch, connected in series with the distribution transformer A1, arranged on the low-voltage side of the distribution transformer A1, and the compensation branch comprises a star compensation branch and / or a delta compensation branch.

[0011] In one embodiment, a second lightning arrester FB2 is further arranged in the compensation branch, and the second lightning arrester FB2 is arranged upstream of the compensation branch.

[0012] In one embodiment, the power consumption branch is connected in parallel with the compensation branch, and the power consumption branch includes a load and a detection switch connected in series.

[0013] In one embodiment, the low-voltage side of the capacity-increasing transformer A2 is connected downstream of at least one of the detection switches through the second capacity-increasing switch K22.

[0014] In one embodiment, a distribution substation capacity-increasing device further includes: second current transformers L2, L3 and a second fuse, and the second current transformers L2, L3 and the second fuse are arranged on the low-voltage side of the distribution transformer A1.

[0015] The beneficial effects of the present utility model are as follows:

[0016] The present utility model connects a transformer (capacity-increasing transformer) in parallel with the original transformer in the distribution substation, and controls the on-off of the original transformer (distribution transformer) and the added transformer through a distribution switch and a second capacity-increasing switch. When the load of the original transformer is large, the original transformer and the added transformer work simultaneously; when the load of the original transformer is small, only the original transformer works or the added transformer works.

[0017] Furthermore, the two transformers of the present invention are installed in the same distribution substation, and there is no need to set up new utility poles, effectively saving space costs and economic costs. Description of the Drawings

[0018] By reading the following detailed description with reference to the drawings, the above and other objects, features and advantages of the exemplary embodiments of the present utility model will become readily understood. In the drawings, several embodiments of the present utility model are shown in an exemplary rather than restrictive manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0019] Figure 1 is a circuit schematic diagram for implementing a distribution substation capacity-increasing device according to an embodiment of the present utility model. Detailed Embodiments

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0021] The following will describe in detail the specific embodiments of the present utility model with reference to the drawings.

[0022] Figure 1It is the circuit schematic diagram of a power distribution substation capacity increase device according to an embodiment of the present utility model.

[0023] As shown in the figure, a power distribution substation capacity increase device includes: a power distribution switch K1, a second capacity increase switch K22, and a power taking device.

[0024] Among them, there is a capacity increase transformer A2, whose high-voltage side is connected to the power grid. The capacity increase transformer A2 converts the received high-voltage electricity into low-voltage electricity and outputs electric energy to at least one electrical branch through the low-voltage side; a power taking device, which is connected in series with the capacity increase transformer A2 and is arranged on the high-voltage side of the capacity increase transformer A2; the power taking device includes a power taking coil and a capacitor connected in series. One end of the primary side coil of the power taking coil is connected to the line of the high-voltage side of the capacity increase transformer A2 through the capacitor, and the other end of the primary side coil is grounded; a first capacity increase switch K21 and a second capacity increase switch K22, the first capacity increase switch K21 and the second capacity increase switch K22 are connected in series with the capacity increase transformer A2, and the first capacity increase switch K21 and the second capacity increase switch K22 are opened or closed simultaneously. The first capacity increase switch K21 is arranged between the high-voltage side of the capacity increase transformer A2 and the power taking device, and the second capacity increase switch K22 is arranged on the low-voltage side of the capacity increase transformer A2.

[0025] Furthermore, a power distribution substation capacity increase device further includes: a power distribution transformer A1 and a power distribution switch K1. The power distribution transformer A1 is connected in parallel with the capacity increase transformer A2. Among them, the high-voltage side of the power distribution transformer A1 and the high-voltage side of the capacity increase transformer A2 are both connected to the power grid, and the low-voltage side of the power distribution transformer A1 outputs electric energy to multiple electrical branches; the power distribution switch K1 is connected in series with the power distribution transformer A1, and the power distribution switch K1 is arranged on the high-voltage side of the capacity increase transformer A2. Among them, the power distribution transformer A1 and the capacity increase transformer A2 are installed in the same power distribution area.

[0026] It should be noted that both the low-voltage sides of the power distribution transformer A1 and the capacity increase transformer A2 can receive low-voltage electricity and convert the low-voltage electricity into high-voltage electricity and then input it into the power grid. In one embodiment, the low-voltage side of the power distribution transformer A1 or / and the capacity increase transformer A2 receives the electric energy generated by distributed photovoltaic power generation devices, converts the electric energy output by the photovoltaic power generation devices into high-voltage electricity and then inputs it into the power grid to achieve photovoltaic grid connection.

[0027] Among them, the distribution switch K1 is used to protect and control electrical equipment. For example, when the current in the line where the distribution switch K1 is located exceeds the predetermined maximum allowable value, the distribution switch K1 will automatically disconnect the circuit, thereby preventing the equipment from being damaged due to excessive current; or when the current in the line where the distribution switch K1 is located is higher than the rated current value for a long time but does not reach the short - circuit level, K1 will automatically disconnect the circuit to prevent the components in the line from being damaged due to long - term over - load operation. Based on this, the distribution switch K1 can effectively protect the electrical system from faults and unexpected situations.

[0028] In one embodiment, the distribution transformer A1 is in the working state, and the capacity - increasing transformer A2 is not working. At this time, the distribution switch K1 is in the on state, and the first capacity - increasing switch K21 and the second capacity - increasing switch K22 are in the off state. At this time, the distribution transformer A1 outputs electrical energy to all the power - consuming branches in a region. In other embodiments, the capacity - increasing transformer A2 is in the working state, and the distribution transformer A1 is not working. At this time, the first capacity - increasing switch K21 and the second capacity - increasing switch K22 are in the on state, and the distribution switch K1 is in the off state. At this time, the capacity - increasing transformer A2 outputs electrical energy to all the power - consuming branches in a region. It should be noted that in the above two embodiments, the load of the transformer is within the safe range. By alternately operating the distribution transformer A1 and the capacity - increasing transformer A2, on the one hand, when one transformer fails, the other transformer can immediately take over the load, thereby reducing the power - off time and ensuring continuous power supply. On the other hand, the alternate operation can avoid a single transformer being in a full - load or over - load state for a long time, reducing the operating pressure of the equipment and extending the service life of the transformer.

[0029] In another embodiment, the distribution transformer A1 and the capacity - increasing transformer A2 work simultaneously. At this time, the distribution switch K1, the first capacity - increasing switch K21 and the second capacity - increasing switch K22 are in the on state. At this time, the capacity - increasing transformer A2 outputs electrical energy to at least one power - consuming branch in a region, and the distribution transformer A1 outputs electrical energy to the remaining power - consuming branches in this region. Thus, a reasonable distribution of the electrical load in this region is achieved, thereby avoiding the problem of insufficient transformer capacity.

[0030] It should be noted that there is one or more capacity - increasing transformers A1 to achieve a single - fold or multi - fold capacity increase for the distribution sub - station area. Among them, when there are multiple capacity - increasing transformers A1, the capacity - increasing transformers A1 are connected in parallel to evenly distribute the load current.

[0031] Among them, the power-taking device detects the secondary-side voltage value of the power-taking coil, and obtains the voltage value of the primary side of the power-taking transformer according to the turns ratio relationship between the primary side and the secondary side of the power-taking coil. This voltage value of the primary side is the voltage value of the high-voltage side of the step-up transformer A2 (the input end of the second step-up switch K22), thereby realizing the monitoring of the voltage of the high-voltage side of the step-up transformer A2 that is about to work or has already worked. The voltage value of the high-voltage side of the step-up transformer A2 is also the voltage value of the distribution transformer A1.

[0032] Furthermore, a first current transformer L1 is also configured on the high-voltage side of the step-up transformer A2. The first current transformer L1 is used to detect the magnitude of the input current on the high-voltage side of the step-up transformer A2 when the step-up transformer A2 is in the working state. By obtaining

[0033] In one embodiment, when the distribution transformer A1 is in the working state and the step-up transformer A2 is not working, the voltage value of the distribution transformer A1 is obtained through the power-taking device, and it is judged whether this voltage value is too close to or exceeds the rated voltage value of the high-voltage side of the distribution transformer. When the voltage value obtained by the power-taking device is too close to or exceeds the rated voltage value of the high-voltage side of the distribution transformer, the first step-up switch K21 and the second step-up switch K22 are turned on, so that the distribution transformer A1 and the step-up transformer A2 work simultaneously.

[0034] In another embodiment, when any one of the distribution transformer A1 and the step-up transformer A2 is in the working state and the other transformer is not in the working state, if the working time of the transformer is too long or a fault occurs (the working time exceeds the threshold), then the other transformer (which is not in the working state) replaces the transformer (which is in the working state) to work.

[0035] In one embodiment, both the distribution transformer A1 and the step-up transformer A2 are static electrical devices used to change an alternating voltage (current) of a certain value into another or several different values of voltage (current) with the same frequency. Both are used for transmitting electric energy. The place where the distribution transformer A1 is installed is the distribution substation area. In this embodiment, the distribution transformer A1 and the step-up transformer A2 are installed in the same distribution substation area. For example, the distribution transformer A1 and the step-up transformer A2 are installed on a pole, and the distribution transformer A1 and the step-up transformer A2 are installed at different heights on the same pole, or at different positions at the same height on the pole.

[0036] In one embodiment, the high-voltage side of the step-up transformer A2 is connected to the upstream power grid line through a first fuse FU1; the first fuse FU1 is a drop-out fuse.

[0037] Among them, the drop-out fuse is a special type of fuse, usually used in high-voltage circuits or places prone to fire. The working principle of the drop-out fuse is based on the mechanical device inside the fuse. When the current is overloaded, it is affected by thermal expansion, causing the fuse to drop automatically, thus cutting off the circuit.

[0038] In one embodiment, the downstream of the first fuse FU1 is grounded through the first lightning arrester FB1. Among them, the lightning arrester for the substation is an electrical device used to protect the substation and its power distribution system from lightning strikes and overvoltage.

[0039] In one embodiment, a distribution transformer area capacity increase device further includes: a compensation branch, which is connected in series with the distribution transformer A1 and is arranged on the low-voltage side of the distribution transformer A1. The compensation branch includes a star compensation branch and / or a delta compensation branch. A second lightning arrester FB2 is also arranged in the compensation branch, and the second lightning arrester FB2 is arranged upstream of the compensation branch.

[0040] Among them, the delta compensation branch includes three capacitors, and the three capacitors are connected to form a delta topological structure. The delta compensation branch is used to protect the device from the influence of power grid harmonics. The star compensation branch includes three capacitors, and one end of the three capacitors is connected to a common neutral point, forming a star-like structure. The star compensation branch is also a device used to improve the power factor and reduce harmonics in a three-phase power system.

[0041] In one embodiment, the present utility model further includes: a plurality of power consumption branches, which are connected in parallel with the compensation branch. The power consumption branch includes a load and a detection switch connected in series. The power consumption branch receives the electric energy output from the low-voltage side of the distribution transformer or the capacity increase transformer.

[0042] In one embodiment, the low-voltage side of the capacity increase transformer A2 is connected downstream of at least one of the detection switches through the second capacity increase switch K22.

[0043] In one embodiment, the present utility model further includes: second current transformers L2, L3 and a second fuse, and the second current transformers L2, L3 and the second fuse are arranged on the low-voltage side of the distribution transformer A1.

[0044] Furthermore, the downstream of the second fuse FU2 is also grounded through a surge protector SPD. The surge protector is a device used to protect electrical equipment from overvoltage damage. In the power system, due to reasons such as lightning strikes, switch operations, and power grid faults, the voltage may rise instantaneously, and this phenomenon is called a surge. The role of the surge protector is to absorb, disperse or reflect these overvoltages to protect the electrical equipment from damage.

[0045] In the above description of this specification, unless otherwise clearly specified and defined, terms such as "fixed", "installed", "connected" or "coupled" should be understood in a broad sense. For example, with respect to the term "connected", it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, or it can be the communication inside two components or the interaction relationship between two components. Therefore, unless otherwise clearly defined in this specification, those skilled in the art can understand the specific meanings of the above terms in this utility model according to specific circumstances.

[0046] The terms "first", "second", etc. used in this specification to refer to numbered or ordinal terms are for descriptive purposes only and should not be construed as explicitly or implicitly indicating relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" or "second" may explicitly or implicitly include at least one such feature. In the description of this specification, "a plurality of" means at least two, such as two, three or more, etc., unless otherwise specifically and clearly defined.

[0047] Although this specification has shown and described multiple embodiments of the present utility model, it is obvious to those skilled in the art that such embodiments are provided by way of example only. Those skilled in the art will think of many changes, alterations and alternative ways without departing from the spirit and idea of the present utility model. It should be understood that various alternative solutions to the embodiments of the present utility model described herein can be adopted in the process of practicing the present utility model. The appended claims are intended to define the protection scope of the present utility model and thus cover the module compositions, equivalents or alternative solutions within the scope of these claims.

Claims

1. A distribution transformer substation capacity increasing device, characterized in that, Including: A capacity-increasing transformer (A2), whose high-voltage side is connected to the power grid. The capacity-increasing transformer (A2) converts the received high-voltage electricity into low-voltage electricity, and the low-voltage side of the capacity-increasing transformer (A2) outputs electric energy to at least one power-consuming branch. A power-taking device, which is connected in series with the capacity-increasing transformer (A2) and is arranged on the high-voltage side of the capacity-increasing transformer (A2). The power-taking device includes a power-taking coil and a capacitor connected in series. One end of the primary side coil of the power-taking coil is connected to the line of the high-voltage side of the capacity-increasing transformer (A2) through the capacitor, and the other end of the primary side coil is grounded. A first capacity-increasing switch (K21) and a second capacity-increasing switch (K22). The first capacity-increasing switch (K21) and the second capacity-increasing switch (K22) are both connected in series with the capacity-increasing transformer (A2), and the first capacity-increasing switch (K21) and the second capacity-increasing switch (K22) are opened or closed simultaneously. The first capacity-increasing switch (K21) is arranged between the high-voltage side of the capacity-increasing transformer (A2) and the power-taking device, and the second capacity-increasing switch (K22) is arranged on the low-voltage side of the capacity-increasing transformer (A2).

2. The capacity increasing device for a distribution substation area according to claim 1, wherein Also including: A distribution transformer (A1) and a distribution switch (K1). The distribution transformer (A1) is connected in parallel with the capacity-increasing transformer (A2). Among them, the high-voltage sides of the distribution transformer (A1) and the capacity-increasing transformer (A2) are both connected to the power grid, and the low-voltage side of the distribution transformer (A1) outputs electric energy to multiple power-consuming branches. The distribution switch (K1) is connected in series with the distribution transformer (A1), and the distribution switch (K1) is arranged on the high-voltage side of the capacity-increasing transformer (A2). Among them, the distribution transformer (A1) and the capacity-increasing transformer (A2) are installed in the same distribution area.

3. The capacity increasing device for a distribution substation area according to claim 1, wherein The high-voltage side of the capacity-increasing transformer (A2) is also configured with a first current transformer (L1).

4. The capacity increasing device for a distribution substation area according to claim 1, wherein The high-voltage side of the capacity-increasing transformer (A2) is connected to the upstream power grid line through a first fuse (FU1). The first fuse (FU1) is a drop-out fuse.

5. The capacity increasing device for a distribution transformer area according to claim 4, wherein, The downstream of the first fuse (FU1) is grounded through a first lightning arrester (FB1).

6. The capacity increasing device for a distribution transformer substation according to claim 2, wherein Also including: A compensation branch, which is connected in series with the distribution transformer (A1) and is arranged on the low-voltage side of the distribution transformer (A1). The compensation branch includes a star compensation branch and / or a delta compensation branch.

7. The capacity increasing device for a distribution substation area according to claim 6, characterized in that, A second lightning arrester (FB2) is also arranged in the compensation branch, and the second lightning arrester (FB2) is arranged upstream of the compensation branch.

8. The capacity increasing device for a distribution substation area according to claim 6, characterized in that, The power-consuming branch is connected in parallel with the compensation branch, and the power-consuming branch includes a load and a detection switch connected in series.

9. The capacity increasing device for a distribution substation area according to claim 8, wherein, The low-voltage side of the capacity-increasing transformer (A2) is connected downstream of at least one of the detection switches through the second capacity-increasing switch (K22).

10. The capacity-increasing device for a distribution transformer substation according to claim 2, characterized in that, Also including: Second current transformers (L2, L3) and a second fuse, and the second current transformers (L2, L3) and the second fuse are arranged on the low-voltage side of the distribution transformer (A1).

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