Power distribution system, hybrid power distribution transformer and integration method and related devices

Abstract

This invention relates to the field of distribution transformer technology, and more particularly to a distribution system, a hybrid distribution transformer, an integration method, and related devices. In the hybrid distribution transformer, an intermediate yoke exists between the main transformer and the auxiliary transformer; a first three-phase secondary winding is wound on the side of the main transformer closest to the intermediate yoke; a three-phase primary winding is wound on the side of the main transformer furthest from the intermediate yoke; a second three-phase secondary winding is wound on the side of the auxiliary transformer closest to the intermediate yoke; a three-phase auxiliary winding is wound on the side of the auxiliary transformer furthest from the intermediate yoke; the windings of the same phase in the three-phase auxiliary winding and the three-phase primary winding are not axially symmetrically distributed; one end of the windings of the same phase in the first three-phase secondary winding and the second three-phase secondary winding are interconnected, thus solving the technical problems of high cost and large size of existing hybrid distribution transformers.

Description

Technical Field

[0001] This invention relates to the field of power distribution transformer technology, and in particular to a power distribution system, a hybrid power distribution transformer and its integration method and related devices. Background Technology

[0002] With the construction of new power systems, the large-scale grid connection of renewable energy, and increasingly refined power quality control requirements, coupled with the continuous introduction of various sensitive loads, the operating environment of distribution substations is becoming increasingly complex, posing new and higher challenges to their safe and stable operation. Traditional power frequency transformers, as the core equipment of distribution substations, can only achieve basic voltage level transformation and power transmission. They lack the ability to actively suppress grid disturbances and improve power quality, and also lack communication interaction modules, making them unable to participate in the communication and coordinated operation of other equipment in the grid. Therefore, they are no longer suitable for the current operational needs of distribution substations. To meet the new operational requirements of distribution substations, existing technologies have proposed hybrid distribution transformers (HDTs) that integrate traditional power frequency transformers with small-capacity power electronic converters. Based on the hybrid architecture of main power transmission from power frequency transformers and fine-tuning from power electronic converters, the HDT can provide stable and powerful support for the node voltage of distribution substations, while effectively achieving comprehensive power quality management such as harmonic mitigation, reactive power compensation, and three-phase imbalance suppression, effectively overcoming the functional limitations of traditional transformers. However, in the actual engineering application of hybrid distribution transformers, the limited installation space in existing distribution substations becomes a prominent issue. Conventional hybrid distribution transformers, due to their dispersed components and insufficient integration, face problems such as large size, high deployment difficulty, and high overall cost. Therefore, integrating and optimizing hybrid distribution transformers to reduce equipment size and lower construction and maintenance costs has become a necessary prerequisite for their engineering promotion and large-scale application.

[0003] To achieve integrated design of hybrid distribution transformers to fit the limited installation space in distribution substations, existing technologies first add a magnetic core to a traditional transformer. Series and parallel converters are then connected to the improved magnetic core structure via windings, initially completing the integration of the hybrid distribution transformer. However, this approach still retains four windings, and the additional magnetic core results in a relatively large size after integration. To address this, existing technologies have also proposed directly connecting the parallel converter to the low-voltage distribution network. By simplifying the winding and magnetic core configuration, the size of the integrated hybrid distribution transformer is effectively reduced, while simultaneously lowering equipment costs. This achieves an optimization of the single-phase AC / DC scheme for integrated hybrid distribution transformers. At that time, three-phase scenarios were the mainstream application in actual power distribution systems. Existing single-phase integrated solutions could not directly adapt to the operational needs of three-phase distribution substations. Therefore, existing technology further proposed a split secondary winding hybrid distribution transformer (SSW-HDT) solution, specifically completing the integrated design of three-phase hybrid distribution transformers, making the integrated solution more suitable for actual engineering applications. However, the intermediate yoke of this split secondary winding hybrid distribution transformer is prone to magnetic flux saturation. To avoid this risk, the cross-sectional area of ​​the intermediate yoke of the split secondary winding hybrid distribution transformer had to be increased during actual production. However, the increased cross-sectional area of ​​the intermediate yoke of the split secondary winding hybrid distribution transformer led to a corresponding increase in the size of the transformer, and also added additional manufacturing costs, making it difficult to achieve the goals of HDT integration, miniaturization, and low cost.

[0004] As can be seen from the above, under the premise of ensuring that the original core functions of the hybrid distribution transformer, such as voltage support and power quality management, are not affected, how to reduce the maximum magnetic flux that may occur in the intermediate yoke without increasing the cross-sectional area of ​​the intermediate yoke, and thus reduce the cost and size of the HDT equipment, has become an urgent technical problem to be solved. Summary of the Invention

[0005] This invention provides a power distribution system, a hybrid power distribution transformer, an integration method, and related devices to solve the technical problems of high cost and large size of existing hybrid power distribution transformers.

[0006] The present invention provides a hybrid distribution transformer, comprising: a main transformer, an auxiliary transformer, a three-phase primary winding, a first three-phase secondary winding, a second three-phase secondary winding, and a three-phase auxiliary winding;

[0007] The yoke of the main transformer near the auxiliary transformer, or the yoke of the auxiliary transformer near the main transformer, forms the intermediate yoke of the hybrid distribution transformer;

[0008] The first three-phase secondary winding is wound on the side of the main transformer near the intermediate yoke;

[0009] The three-phase primary winding is wound on the side of the main transformer away from the intermediate yoke;

[0010] The second and third phase secondary windings are wound on the side of the auxiliary transformer closest to the intermediate yoke;

[0011] The three-phase auxiliary winding is wound on the side of the auxiliary transformer away from the intermediate yoke;

[0012] In the three-phase auxiliary winding and the three-phase primary winding, the windings of the same phase are not axially symmetrically distributed.

[0013] In the first three-phase secondary winding and the second three-phase secondary winding, one end of the windings of the same phase is connected to each other.

[0014] Optionally, the first three-phase secondary winding includes a first A-phase secondary winding, a first B-phase secondary winding, and a first C-phase secondary winding; the second three-phase secondary winding includes a second A-phase secondary winding, a second B-phase secondary winding, and a second C-phase secondary winding.

[0015] The same-name terminal of the first phase A secondary winding is connected to the opposite-name terminal of the second phase A secondary winding;

[0016] The same-name terminal of the first phase B secondary winding is connected to the opposite-name terminal of the second phase B secondary winding;

[0017] The same-name terminal of the first C-phase secondary winding is connected to the opposite-name terminal of the second C-phase secondary winding.

[0018] Optionally, the core column of the main transformer is made of the same material as the core column of the auxiliary transformer;

[0019] The cross-sectional area of ​​the magnetic core column of the main transformer is the same as that of the magnetic core column of the auxiliary transformer.

[0020] Optionally, the turns ratio of the three-phase primary winding, the first three-phase secondary winding, the three-phase auxiliary winding, and the second three-phase secondary winding satisfies 250:10:10:1.

[0021] Optionally, the main transformer and the auxiliary transformer are core-type transformers.

[0022] Optionally, it also includes: a first converter and a second converter;

[0023] The first converter is connected to the three-phase auxiliary winding;

[0024] The second converter is connected to the first three-phase secondary winding and the second three-phase secondary winding;

[0025] The first converter and the second converter are connected by a capacitor assembly.

[0026] Another aspect of the present invention provides a power distribution system, comprising: a first AC power grid, a second AC power grid, and a hybrid power distribution transformer as described above;

[0027] The three-phase lines of the first AC power grid are connected to the three-phase primary windings of the hybrid distribution transformer;

[0028] The three-phase lines of the second AC power grid are connected to the first three-phase secondary winding and the second three-phase secondary winding of the hybrid distribution transformer;

[0029] The voltage level of the second AC power grid is lower than that of the first AC power grid.

[0030] Another aspect of the present invention provides an integration method for a hybrid distribution transformer, applied to the hybrid distribution transformer described above, the integration method comprising:

[0031] Obtain a location setup plan, which includes the structure of the main transformer, the structure of the auxiliary transformer, the relative positions of the main transformer and the auxiliary transformer, the winding positions of the three-phase primary windings, the winding positions of the first three-phase secondary windings, the winding positions of the second three-phase secondary windings, and the winding positions of the three-phase auxiliary windings.

[0032] According to the aforementioned location construction plan, the main transformer and the auxiliary transformer are constructed, and the three-phase primary winding and the first three-phase secondary winding are wound on the main transformer, while the second three-phase secondary winding and the three-phase auxiliary winding are wound on the auxiliary transformer.

[0033] Another aspect of the present invention provides an integrated device for a hybrid distribution transformer, comprising:

[0034] The acquisition module is used to acquire the location construction plan, which includes the structure of the main transformer, the structure of the auxiliary transformer, the relative positions of the main transformer and the auxiliary transformer, the winding positions of the three-phase primary windings, the winding positions of the first three-phase secondary windings, the winding positions of the second three-phase secondary windings, and the winding positions of the three-phase auxiliary windings.

[0035] The module is used to construct the main transformer and the auxiliary transformer according to the location construction plan, and to wind the three-phase primary winding and the first three-phase secondary winding onto the main transformer, and to wind the second three-phase secondary winding and the three-phase auxiliary winding onto the auxiliary transformer.

[0036] Another aspect of the present invention provides an electronic device, the device including a processor and a memory;

[0037] The memory is used to store program code and transmit the program code to the processor;

[0038] The processor is used to execute the method described above according to the instructions in the program code.

[0039] As can be seen from the above technical solutions, the present invention has the following advantages:

[0040] This invention provides a hybrid distribution transformer, comprising: a main transformer, an auxiliary transformer, three-phase primary windings, a first three-phase secondary winding, a second three-phase secondary winding, and a three-phase auxiliary winding; the yoke of the main transformer near the auxiliary transformer, or the yoke of the auxiliary transformer near the main transformer, forms the intermediate yoke of the hybrid distribution transformer; the first three-phase secondary winding is wound on the side of the main transformer near the intermediate yoke; the three-phase primary winding is wound on the side of the main transformer away from the intermediate yoke; the second three-phase secondary winding is wound on the side of the auxiliary transformer near the intermediate yoke; the three-phase auxiliary winding is wound on the side of the auxiliary transformer away from the intermediate yoke; the windings of the same phase in the three-phase auxiliary winding and the three-phase primary winding are not axially symmetrically distributed; one end of the windings of the same phase in the first three-phase secondary winding and the second three-phase secondary winding are interconnected.

[0041] In this invention, the yoke of the main transformer near the auxiliary transformer, or the yoke of the auxiliary transformer near the main transformer, forms the intermediate yoke of the hybrid distribution transformer. The three-phase primary windings are wound on the side of the main transformer away from the intermediate yoke; the second and third-phase secondary windings are wound on the side of the auxiliary transformer near the intermediate yoke; and the three-phase auxiliary windings are wound on the side of the auxiliary transformer away from the intermediate yoke. This allows the upper yoke of the primary excitation branch of the hybrid distribution transformer and the lower yoke of the auxiliary excitation branch to share a single yoke, thereby achieving the integration of the magnetic core of the three-phase hybrid distribution transformer, and thus reducing the cost of the hybrid distribution transformer core. In terms of volume, in the first and second phase secondary windings, the ends of the windings of the same phase are connected to each other. In the three-phase auxiliary winding and the three-phase primary winding, the positions of the windings of the same phase do not form an axisymmetric distribution. As a result, the phase voltages of the windings wound on the same column of magnetic cores of the main transformer and the auxiliary transformer are not the same phase. Based on this, the maximum magnetic flux of the intermediate yoke of the hybrid distribution transformer is reduced. Therefore, the hybrid distribution transformer provided by this invention does not need to increase the cross-sectional area of ​​the intermediate yoke. Compared with the prior art, it reduces the cost and volume of the hybrid distribution transformer. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the structure of a hybrid power distribution transformer provided in an embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram of the structure of a core-type transformer provided in an embodiment of the present invention;

[0045] Figure 3 A schematic diagram showing that the phase voltages of the windings wound on the same column of magnetic core columns of the main transformer and the auxiliary transformer are all in phase, provided for an embodiment of the present invention.

[0046] Figure 4 This is a schematic diagram of a power distribution system provided in an embodiment of the present invention;

[0047] Figure 5 The simulation application example provided by this invention is in three-phase v ix When the overvoltage is 10%, refer to the waveform diagram of the magnetic flux corresponding to the primary winding, auxiliary winding and intermediate yoke of the hybrid distribution transformer, as well as the output voltage of the a-phase winding.

[0048] Figure 6 The simulation application example provided by this invention is in three-phase v ix A schematic diagram of the magnetic flux corresponding to the primary winding, auxiliary winding, and intermediate yoke of a hybrid distribution transformer, as well as the output voltage of phase a winding, when the overvoltage is 10%.

[0049] Figure 7 The three-phase v provided by the embodiments of the present invention ix When the voltage drops by 10%, refer to the waveform diagram of the magnetic flux corresponding to the primary winding, auxiliary winding, and intermediate yoke of the hybrid distribution transformer, as well as the output voltage of the a-phase winding.

[0050] Figure 8 The three-phase v provided by the embodiments of the present invention ix A schematic diagram of the magnetic flux corresponding to the primary winding, auxiliary winding, and intermediate yoke of the hybrid distribution transformer, as well as the output voltage of the a-phase winding, when the voltage drops by 10%.

[0051] Figure 9 A flowchart illustrating an integration method for a hybrid distribution transformer provided in an embodiment of the present invention;

[0052] Figure 10 A structural block diagram of an integrated device for a hybrid distribution transformer provided in an embodiment of the present invention;

[0053] Figure 11 This is a structural block diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0054] This invention provides a power distribution system, a hybrid power distribution transformer, an integration method, and related devices to solve the technical problems of high cost and large size of existing hybrid power distribution transformers.

[0055] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0056] Please see Figure 1 , Figure 1 This is a schematic diagram of a hybrid power distribution transformer provided in an embodiment of the present invention.

[0057] The present invention provides a hybrid distribution transformer, comprising: a main transformer, an auxiliary transformer, a three-phase primary winding, a first three-phase secondary winding, a second three-phase secondary winding, and a three-phase auxiliary winding;

[0058] The yoke of the main transformer near the auxiliary transformer, or the yoke of the auxiliary transformer near the main transformer, forms the intermediate yoke of the hybrid distribution transformer.

[0059] The first and third phase secondary windings are wound on the side of the main transformer near the middle yoke;

[0060] The three-phase primary winding is wound on the side of the main transformer away from the intermediate yoke;

[0061] The second and third phase secondary windings are wound on the side of the auxiliary transformer near the middle yoke;

[0062] The three-phase auxiliary winding is wound on the side of the auxiliary transformer away from the intermediate yoke;

[0063] In the three-phase auxiliary winding and the three-phase primary winding, the positions of the windings of the same phase do not form an axisymmetric distribution;

[0064] In the first and third phase secondary windings and the second and third phase secondary windings, one end of the windings of the same phase is connected to each other.

[0065] It should be noted that the main transformer and auxiliary transformer have the same structure, consisting of two parts: the magnetic core columns and the magnetic yoke. The magnetic core columns are the vertically distributed magnetic core sections, serving as the winding carrier for the windings. The magnetic yoke is the magnetic core section vertically connected to both ends of the magnetic core columns, and its material is the same as that of the magnetic core columns. The magnetic yoke is the yoke in this embodiment. In this embodiment, both the main transformer and the auxiliary transformer are three-phase transformers, and the three-phase transformer has three sets of magnetic core columns.

[0066] In one embodiment, the core column of the main transformer is made of the same material as the core column of the auxiliary transformer;

[0067] The cross-sectional area of ​​the magnetic core column of the main transformer is the same as that of the magnetic core column of the auxiliary transformer.

[0068] It should be noted that, in order to further reduce manufacturing costs, the cross-sectional area and material of the magnetic core column of the main transformer are the same as those of the magnetic core column of the auxiliary transformer. Therefore, the maximum magnetic flux allowed to flow through the main transformer is the same as that allowed to flow through the auxiliary transformer.

[0069] In one embodiment, the main transformer and the auxiliary transformer are core-type transformers.

[0070] The core-type transformer is made entirely of silicon steel sheets, such as Figure 2 As shown, in the vertical direction, three sets of magnetic cores are formed by three stacked silicon steel sheets at a predetermined distance, and the horizontally stacked silicon steel sheets that vertically connect the upper and lower ends of the three sets of magnetic cores form the upper and lower yokes of the heart-shaped transformer.

[0071] In this embodiment, taking the main transformer and auxiliary transformer as core-type transformers as an example, such as... Figure 1 As shown, the auxiliary transformer and the main transformer are installed sequentially from top to bottom. Figure 1 In the diagram, the transformer located at the top is the auxiliary transformer, and the transformer located at the bottom is the main transformer. According to... Figure 2 As can be seen from the structure of the heart-shaped transformer shown, there are yokes at both the upper and lower ends of the heart-shaped transformer. Figure 1 In this configuration, the main transformer is positioned below the auxiliary transformer, allowing them to share a yoke. This means that adjacent yokes of the main and auxiliary transformers are integrated into a single yoke. Therefore, the yoke closest to the auxiliary transformer from the main transformer can be selected as the shared yoke for both transformers; in other words, the yoke of the auxiliary transformer closest to the main transformer uses the yoke of the main transformer as its own yoke. Similarly, the yoke closest to the main transformer from the auxiliary transformer can also be selected as the shared yoke for both transformers. In this case, the yoke of the main transformer closest to the auxiliary transformer uses the yoke of the auxiliary transformer as its own yoke.

[0072] Therefore, by setting the main transformer and auxiliary transformer to share the same yoke, the magnetic core of the hybrid distribution transformer is integrated, reducing the amount of silicon steel sheets used, thereby reducing the material cost of the magnetic core, and reducing the physical size of the magnetic core, thereby reducing the volume and weight of the entire hybrid distribution transformer, making the hybrid distribution transformer more convenient to install in distribution substations in practical engineering applications.

[0073] It is understandable that the position of the auxiliary transformer's yoke closest to the main transformer can be determined based on the actual location of the main and auxiliary transformers in the application. Similarly, the position of the auxiliary transformer's yoke closest to the main transformer can be determined based on the actual location of the main and auxiliary transformers in the application.

[0074] In this embodiment, the main transformer and the auxiliary transformer constitute the main structure of the hybrid distribution transformer. Since the common yoke of the main transformer and the auxiliary transformer is distributed in the middle of the main structure in actual applications, this embodiment uses the common yoke as the middle yoke of the hybrid distribution transformer.

[0075] In this embodiment, the three-phase primary winding includes an A-phase primary winding, a B-phase primary winding, and a C-phase primary winding. The A-phase primary winding is used to connect to the A-phase transmission line on the primary side, and its voltage is the A-phase voltage. The B-phase primary winding is used to connect to the B-phase transmission line on the primary side, and its voltage is the B-phase voltage. The C-phase primary winding is used to connect to the C-phase transmission line on the primary side, and its voltage is the C-phase voltage.

[0076] In this embodiment, the first three-phase secondary winding and the second three-phase secondary winding can be classified as secondary windings, the difference being that the first three-phase secondary winding and the second three-phase secondary winding have different numbers of turns. Specifically, the first three-phase secondary winding includes a first A-phase secondary winding, a first B-phase secondary winding, and a first C-phase secondary winding; the second three-phase secondary winding includes a second A-phase secondary winding, a second B-phase secondary winding, and a second C-phase secondary winding.

[0077] In the first and third phase secondary windings and the second and third phase secondary windings, the ends of the windings of the same phase are connected to each other. Specifically:

[0078] One end of the secondary winding of the first phase A is connected to one end of the secondary winding of the second phase A, while the other end of the secondary winding of the first phase A and the other end of the secondary winding of the second phase A are respectively used to connect to the secondary phase A transmission line.

[0079] One end of the first phase B secondary winding is connected to one end of the second phase B secondary winding, while the other end of the first phase B secondary winding and the other end of the second phase B secondary winding are respectively used to connect to the secondary phase B transmission line.

[0080] One end of the first C-phase secondary winding is connected to one end of the second C-phase secondary winding, while the other end of the first C-phase secondary winding and the other end of the second C-phase secondary winding are respectively used to connect to the secondary C-phase transmission line.

[0081] In this embodiment, the three-phase auxiliary winding includes: an A-phase auxiliary winding, a B-phase auxiliary winding, and a C-phase auxiliary winding. The A-phase auxiliary winding, B-phase auxiliary winding, and C-phase auxiliary winding are respectively used to connect to the first converter.

[0082] In this embodiment, the first three-phase secondary winding and the second three-phase secondary winding are wound on the main transformer and the auxiliary transformer on both sides of the intermediate yoke, respectively. The three-phase primary winding is wound below the first three-phase secondary winding, and the three-phase auxiliary winding is wound above the second three-phase secondary winding.

[0083] Specifically, such as Figure 1As shown, the A-phase primary winding, B-phase primary winding, and C-phase primary winding of the three-phase primary winding are wound on the three magnetic core columns below the main transformer. Above the A-phase primary winding, B-phase primary winding, and C-phase primary winding, the first A-phase secondary winding, the first B-phase secondary winding, and the first C-phase secondary winding are wound. Above the intermediate yoke, on the three magnetic core columns of the auxiliary transformer, the second A-phase secondary winding, the second B-phase secondary winding, and the second C-phase secondary winding are wound. Above the second A-phase secondary winding, the second B-phase secondary winding, and the second C-phase secondary winding, the A-phase auxiliary winding, the B-phase auxiliary winding, and the C-phase auxiliary winding are wound.

[0084] In this embodiment, both the three-phase primary winding and the three-phase auxiliary winding are excitation windings. When an excitation current is applied to the three-phase primary winding and the three-phase auxiliary winding, both windings generate corresponding excitation flux. Based on the winding positions of the three-phase primary winding, the first three-phase secondary winding, the second three-phase secondary winding, and the three-phase auxiliary winding, it can be seen that the excitation flux generated by the three-phase primary winding acts on the first three-phase secondary winding, causing it to generate a first secondary three-phase voltage; the excitation flux generated by the three-phase auxiliary winding acts on the second three-phase secondary winding, causing it to generate a second secondary three-phase voltage. The first and second secondary three-phase voltages together constitute the three-phase output voltage of the secondary side of the hybrid distribution transformer. As mentioned above, the main transformer and the auxiliary transformer share the same intermediate yoke. Therefore, the upper yoke of the primary excitation branch (the excitation branch composed of the three-phase primary winding and the first three-phase secondary winding) of the main transformer and the lower yoke of the auxiliary excitation branch (the excitation branch composed of the three-phase auxiliary winding and the second three-phase secondary winding) share the same yoke.

[0085] In this embodiment, the fact that the windings of the same phase in the three-phase auxiliary windings and the three-phase primary windings do not form an axisymmetric distribution means that, with the intermediate yoke as the axis of symmetry, the winding positions of the windings used to connect the transmission lines of the same phase in the three-phase auxiliary windings and the three-phase primary windings do not form an axisymmetric distribution. Here, "windings of the same phase" refers to windings used to connect transmission lines representing the same phase. For example, auxiliary windings and primary windings used to connect the A-phase transmission line are considered windings of the same phase.

[0086] by Figure 1 Taking the structure shown as an example, such as Figure 1 As shown, the primary winding of phase A, used to connect the phase A transmission line, is wound on the leftmost magnetic core column of the main transformer, while the auxiliary winding used to connect the phase A transmission line is wound on the rightmost magnetic core column of the auxiliary transformer. The leftmost magnetic core column of the main transformer and the rightmost magnetic core column of the auxiliary transformer do not form an axisymmetric distribution.

[0087] The following will combine the above examples and Figure 1 This explains the principle behind how the hybrid distribution transformer provided by this invention can reduce the maximum magnetic flux of the intermediate yoke.

[0088] As can be seen from the foregoing description, the secondary winding group in this embodiment is divided into a first three-phase secondary winding group and a second three-phase secondary winding group. Figure 1 In, N i and N s These represent the number of turns in the three-phase primary winding and the number of turns in the three-phase auxiliary winding, respectively; the number of turns N in the secondary winding. o The number of turns N of the first and third phase secondary windings o1 Number of turns N of the second and third phase secondary windings o2 It consists of two parts; v ix and v sx Let x = (a, b, c) represent the excitation voltage of the three-phase primary winding and the excitation voltage of the three-phase auxiliary winding, respectively; and let v represent the three-phase secondary output voltage. ox The voltage v of the first and third phase secondary windings ox1 Voltage v of the second and third phase secondary windings ox2 It consists of two parts; φ ix and φ sx These represent the magnetic flux flowing through the three-phase primary winding and the three-phase auxiliary winding, respectively; φ flowing through the three-phase secondary winding... ox The magnetic flux φ of the first and third phase secondary windings ox1 The magnetic flux φ of the second and third phase secondary windings ox2 It consists of two parts; φ M1 and φ M2 This represents the magnetic flux flowing through the intermediate yoke of the transformer, such as Figure 1 As shown, φ M1 and φ M2 The directions are opposite.

[0089] As explained above, the magnetic flux generated by the three-phase primary winding produces a voltage v on the three-phase secondary winding. ox1 The magnetic flux generated by the three-phase auxiliary winding produces a voltage v on the secondary winding of the second and third phases. ox2 Together, they constitute the three-phase secondary side output voltage V. ox .

[0090] Assuming the core of the hybrid distribution transformer is in the linear operating region, and ignoring nonlinear factors such as leakage reactance, based on Figure 1 Given the magnetic core structure shown, the three-phase secondary side output voltage expression is as shown in formula (1).

[0091] (1)

[0092] Considering that the power of the first and second converters generally accounts for 10% of that of a traditional transformer, and that for HDTs, considering manufacturing processes, the core materials and cross-sectional areas of the upper and lower windings are the same, the maximum allowable magnetic flux is also the same. Based on this, the turns ratio of each winding must satisfy formula (2).

[0093] (2)

[0094] Based on the above, it can be seen that the magnetic flux φ flowing through the intermediate yoke M1 and φ M2 The expression is shown in formula (3).

[0095] (3)

[0096] Based on this, if the winding positions of the three-phase primary winding, the first three-phase secondary winding, the second three-phase secondary winding, and the three-phase auxiliary winding in a hybrid distribution transformer are symmetrically distributed around the central yoke, then the phase voltages of the windings wound on the same column of the magnetic core in both the main transformer and the auxiliary transformer will be the same phase. Specifically, as... Figure 3 As shown, the phase voltages of the windings wound on the same column of magnetic cores in both the main transformer and the auxiliary transformer are in phase. That is, the upper and lower magnetic core windings correspond to the same phase voltage. Taking the leftmost magnetic core column as an example, in order from top to bottom, they are: A-phase auxiliary winding, second A-phase secondary winding, first A-phase secondary winding, and A-phase primary winding. The voltages corresponding to these four windings are: v sa v oa2 v oa1 and v ia Based on this, according to formula (3), when the primary voltage rises, the first converter will output a negative voltage to ensure the stability of the secondary voltage. At this time, the magnetic flux of the transformer intermediate yoke may reach twice the single-phase excitation flux, which is not conducive to the stable and reliable operation of the system.

[0097] In the hybrid distribution transformer provided in this embodiment, the phase voltages corresponding to the upper and lower magnetic core windings are no longer the same phase. Figure 1 Taking the structure shown as an example, Figure 1 The windings wound on the leftmost magnetic core post, from top to bottom, are: phase B auxiliary winding, second phase B secondary winding, first phase A secondary winding, and phase A primary winding. The phase voltage between the phase B auxiliary winding and the second phase B secondary winding is v. sb v ob2 (That is, the corresponding phase B voltage), the phase voltages corresponding to the first phase A secondary winding and the phase A primary winding are v. oa1 and v ia(i.e., the voltage corresponding to phase A). Based on formula (3), it can be seen that when the three-phase power grid voltage experiences overvoltage or undervoltage, the maximum magnetic flux of the intermediate yoke of the hybrid distribution transformer in this application is less than Figure 3 The magnetic flux of the intermediate yoke of the transformer. For example: taking the maximum compensation voltage of the converter as 10% of the low-voltage bus voltage (400V) as the benchmark, when the three-phase grid voltage has a 10% overvoltage, a compensation voltage of -40V needs to be output. According to formula (3), the magnetic flux of the intermediate yoke of the transformer at this time is only 1 times that of the single-phase excitation magnetic flux; while when the three-phase grid voltage has a 10% undervoltage, a compensation voltage of 40V needs to be output. According to formula (3), the magnetic flux of the intermediate yoke of the transformer at this time is 1.732 times that of the single-phase excitation magnetic flux. In summary, the structure of the hybrid distribution transformer provided by this invention can reduce the maximum magnetic flux of the intermediate yoke to 1.732 times that of the single-phase excitation magnetic flux. Based on this, the structure of the hybrid distribution transformer provided in this embodiment can reduce the maximum magnetic flux of the intermediate yoke. Therefore, when the hybrid distribution transformer provided in this embodiment is applied to actual engineering applications, it is not necessary to increase the cross-sectional area of ​​the intermediate yoke to reduce the maximum magnetic flux. Thus, compared with existing hybrid distribution transformers, the hybrid distribution transformer provided in this embodiment is smaller in size and lower in cost, achieving both cost reduction and size reduction of the hybrid distribution transformer.

[0098] In this embodiment, the yoke of the main transformer near the auxiliary transformer, or the yoke of the auxiliary transformer near the main transformer, forms the intermediate yoke of the hybrid distribution transformer. The three-phase primary winding is wound on the side of the main transformer away from the intermediate yoke; the second and third-phase secondary windings are wound on the side of the auxiliary transformer near the intermediate yoke; and the three-phase auxiliary winding is wound on the side of the auxiliary transformer away from the intermediate yoke. This allows the upper yoke of the primary excitation branch of the hybrid distribution transformer and the lower yoke of the auxiliary excitation branch to share a single yoke, thereby achieving the integration of the core of the three-phase hybrid distribution transformer. This reduces the cost and volume of the hybrid distribution transformer core. Simultaneously, the first and third-phase secondary windings... In the secondary windings of the second and third phases, the ends of the windings of the same phase are connected to each other. In the three-phase auxiliary windings and the three-phase primary windings, the positions of the windings of the same phase do not form an axisymmetric distribution. As a result, the phase voltages of the windings wound on the same column of magnetic cores of the main transformer and the auxiliary transformer are not the same phase. Based on this, the maximum magnetic flux of the intermediate yoke of the hybrid distribution transformer is reduced. Therefore, the hybrid distribution transformer provided in this embodiment does not need to increase the cross-sectional area of ​​the intermediate yoke. Compared with the prior art, the cost of the hybrid distribution transformer is reduced, the volume of the hybrid distribution transformer is reduced, and the technical problems of high cost and large volume of the existing hybrid distribution transformer are solved.

[0099] In one embodiment, the first three-phase secondary winding includes a first A-phase secondary winding, a first B-phase secondary winding, and a first C-phase secondary winding; the second three-phase secondary winding includes a second A-phase secondary winding, a second B-phase secondary winding, and a second C-phase secondary winding; the same-named terminals of the first A-phase secondary winding are connected to the opposite-named terminals of the second A-phase secondary winding; the same-named terminals of the first B-phase secondary winding are connected to the opposite-named terminals of the second B-phase secondary winding; and the same-named terminals of the first C-phase secondary winding are connected to the opposite-named terminals of the second C-phase secondary winding.

[0100] It should be noted that in this embodiment, the ends of the windings connected to each other in the first three-phase secondary winding and the second three-phase secondary winding are the same-name end and the opposite-name end, respectively. Based on this connection, the first three-phase secondary winding and the second three-phase secondary winding form a secondary output circuit.

[0101] Specifically, the same-name terminal of the secondary winding of the first phase A is connected to the opposite-name terminal of the secondary winding of the second phase A. The same-name terminal of the secondary winding of the second phase A and the opposite-name terminal of the first phase A can be used to connect to the A-phase transmission line of the AC power grid. Similarly, the same-name terminal of the secondary winding of the first phase B is connected to the opposite-name terminal of the second phase B. The same-name terminal of the secondary winding of the second phase B and the opposite-name terminal of the first phase B can be used to connect to the B-phase transmission line of the AC power grid. Likewise, the same-name terminal of the secondary winding of the first phase C is connected to the opposite-name terminal of the second phase C. The same-name terminal of the secondary winding of the second phase C and the opposite-name terminal of the first phase C can be used to connect to the C-phase transmission line of the AC power grid.

[0102] Since the magnetic flux generated by the three-phase primary windings acts on the first three-phase secondary windings, and the magnetic flux generated by the three-phase auxiliary windings acts on the second three-phase secondary windings, in practical applications, the phase represented by each winding of the first three-phase secondary windings can be determined based on the three-phase primary windings, and the phase represented by each winding of the second three-phase secondary windings can be determined based on the three-phase auxiliary windings. Based on this, the positions and port types of the first A-phase, first B-phase, and first C-phase secondary windings of the first three-phase secondary windings can be determined, as can the positions and port types of the second A-phase, second B-phase, and second C-phase secondary windings. And the connections can be established according to the above connection relationships.

[0103] by Figure 1 Taking the winding positions of each winding shown in the figure as an example, such as Figure 1As shown, the primary winding of phase A is located on the leftmost core column of the main transformer, the primary winding of phase B is located on the middle core column of the main transformer, and the primary winding of phase C is located on the rightmost core column of the main transformer. Based on this, it can be known that the first three-phase secondary winding on the leftmost core column of the main transformer is the first phase A secondary winding, the first three-phase secondary winding on the middle core column of the main transformer is the first phase B secondary winding, and the first three-phase secondary winding on the rightmost core column of the main transformer is the first phase C secondary winding.

[0104] like Figure 1 As shown, the A-phase auxiliary winding is located on the rightmost magnetic core column of the auxiliary transformer, the B-phase auxiliary winding is located on the leftmost magnetic core column of the auxiliary transformer, and the C-phase auxiliary winding is located on the middle magnetic core column of the auxiliary transformer. Based on this, it can be known that the second and third phase secondary windings on the rightmost magnetic core column of the auxiliary transformer are the second A-phase secondary windings, the second and third phase secondary windings on the leftmost magnetic core column of the auxiliary transformer are the second B-phase secondary windings, and the second and third phase secondary windings on the middle magnetic core column of the auxiliary transformer are the second C-phase secondary windings.

[0105] Based on the same-name and different-name terminals of the primary windings of phase A, phase B, and phase C, and based on the same-name and different-name terminals of the auxiliary windings of phase A, phase B, and phase C, the same-name and different-name terminals of the secondary windings of the first phase A, the first phase B, the first phase C, the second phase A, the second phase B, and the second phase C can be correspondingly determined, such as... Figure 1 As shown, the same-name terminals of the second phase A secondary winding, the second phase B secondary winding, and the second phase C secondary winding are located above the opposite-name terminals, indicated by *.

[0106] therefore, Figure 1 In the main transformer, the same-name terminal of the first phase A secondary winding of the leftmost magnetic core column is connected to the opposite-name terminal of the second phase A secondary winding of the rightmost magnetic core column of the auxiliary transformer. Similarly, the same-name terminal of the first phase B secondary winding of the middle magnetic core column of the main transformer is connected to the opposite-name terminal of the second phase B secondary winding of the leftmost magnetic core column of the auxiliary transformer, and the same-name terminal of the first phase C secondary winding of the rightmost magnetic core column of the main transformer is connected to the opposite-name terminal of the second phase C secondary winding of the middle magnetic core column of the auxiliary transformer.

[0107] Understandable Figure 1 The winding positions of the three-phase primary winding and the three-phase auxiliary winding shown are only one example of winding. Their positions can be adjusted provided that they are not axially symmetrical.

[0108] For example:

[0109] In one alternative implementation, the primary winding of phase A can be wound at the leftmost core post of the main transformer, the primary winding of phase B can be wound at the middle core post of the main transformer, the primary winding of phase C can be wound at the rightmost core post of the main transformer, the auxiliary winding of phase A can be wound at the middle core post of the auxiliary transformer, the auxiliary winding of phase B can be wound at the rightmost core post of the auxiliary transformer, and the auxiliary winding of phase C can be wound at the leftmost core post of the auxiliary transformer.

[0110] In one optional implementation, the primary winding of phase A can be wound at the leftmost core post of the main transformer, the primary winding of phase B can be wound at the rightmost core post of the main transformer, and the primary winding of phase C can be wound at the middle core post of the main transformer. In this case, the auxiliary windings of phase A, phase B, and phase C can have two winding methods:

[0111] Firstly, the A-phase auxiliary winding can be wound at the position of the middle magnetic core column of the auxiliary transformer, the B-phase auxiliary winding can be wound at the position of the leftmost magnetic core column of the auxiliary transformer, and the C-phase auxiliary winding can be wound at the position of the rightmost magnetic core column of the auxiliary transformer.

[0112] Secondly, the A-phase auxiliary winding can be wound at the rightmost core post of the auxiliary transformer, the B-phase auxiliary winding can be wound at the middle core post of the auxiliary transformer, and the C-phase auxiliary winding can be wound at the leftmost core post of the auxiliary transformer.

[0113] In one optional implementation, the primary winding of phase A can be wound at the rightmost core post of the main transformer, the primary winding of phase B can be wound at the leftmost core post of the main transformer, and the primary winding of phase C can be wound at the middle core post of the main transformer. In this case, the auxiliary windings of phase A, phase B, and phase C can have two winding methods:

[0114] Firstly, the A-phase auxiliary winding can be wound at the position of the middle core column of the auxiliary transformer, the B-phase auxiliary winding can be wound at the position of the rightmost core column of the auxiliary transformer, and the C-phase auxiliary winding can be wound at the position of the leftmost core column of the auxiliary transformer.

[0115] Secondly, the A-phase auxiliary winding can be wound at the leftmost core column of the auxiliary transformer, the B-phase auxiliary winding can be wound at the middle core column of the auxiliary transformer, and the C-phase auxiliary winding can be wound at the rightmost core column of the auxiliary transformer.

[0116] In one optional implementation, the primary winding of phase A can be wound at the rightmost core post of the main transformer, the primary winding of phase B can be wound at the middle core post of the main transformer, and the primary winding of phase C can be wound at the leftmost core post of the main transformer. In this case, the auxiliary windings of phase A, phase B, and phase C can have two winding methods:

[0117] Firstly, the A-phase auxiliary winding can be wound at the position of the middle magnetic core column of the auxiliary transformer, the B-phase auxiliary winding can be wound at the position of the leftmost magnetic core column of the auxiliary transformer, and the C-phase auxiliary winding can be wound at the position of the rightmost magnetic core column of the auxiliary transformer.

[0118] Secondly, the A-phase auxiliary winding can be wound at the leftmost core column of the auxiliary transformer, the B-phase auxiliary winding can be wound at the rightmost core column of the auxiliary transformer, and the C-phase auxiliary winding can be wound at the middle core column of the auxiliary transformer.

[0119] In one optional implementation, the primary winding of phase A can be wound at the position of the middle core column of the main transformer, the primary winding of phase B can be wound at the position of the leftmost core column of the main transformer, and the primary winding of phase C can be wound at the position of the rightmost core column of the main transformer. In this case, the auxiliary windings of phase A, phase B, and phase C can have two winding methods:

[0120] Firstly, the A-phase auxiliary winding can be wound at the leftmost core column of the auxiliary transformer, the B-phase auxiliary winding can be wound at the rightmost core column of the auxiliary transformer, and the C-phase auxiliary winding can be wound at the middle core column of the auxiliary transformer.

[0121] Secondly, the A-phase auxiliary winding can be wound at the rightmost core post of the auxiliary transformer, the B-phase auxiliary winding can be wound at the middle core post of the auxiliary transformer, and the C-phase auxiliary winding can be wound at the leftmost core post of the auxiliary transformer.

[0122] In one optional implementation, the primary winding of phase A can be wound at the position of the middle core column of the main transformer, the primary winding of phase B can be wound at the position of the rightmost core column of the main transformer, and the primary winding of phase C can be wound at the position of the leftmost core column of the main transformer. In this case, the auxiliary windings of phase A, phase B, and phase C can have two winding methods:

[0123] Firstly, the A-phase auxiliary winding can be wound at the leftmost core column of the auxiliary transformer, the B-phase auxiliary winding can be wound at the middle core column of the auxiliary transformer, and the C-phase auxiliary winding can be wound at the rightmost core column of the auxiliary transformer.

[0124] Secondly, the A-phase auxiliary winding can be wound at the position of the rightmost magnetic core column of the auxiliary transformer, the B-phase auxiliary winding can be wound at the position of the leftmost magnetic core column of the auxiliary transformer, and the C-phase auxiliary winding can be wound at the position of the middle magnetic core column of the auxiliary transformer.

[0125] In one embodiment, the turns ratio of the three-phase primary winding, the first three-phase secondary winding, the three-phase auxiliary winding, and the second three-phase secondary winding satisfies 250:10:10:1.

[0126] It should be noted that in this embodiment, the turns ratio of the three-phase primary winding, the first three-phase secondary winding, the three-phase auxiliary winding, and the second three-phase secondary winding is 250:10:10:1. That is, the turns ratio of each phase winding in the three-phase primary winding, the first three-phase secondary winding, the three-phase auxiliary winding, and the second three-phase secondary winding also satisfies 250:10:10:1.

[0127] Specifically, the turns ratio of the primary winding of phase A, the first secondary winding of phase A, the auxiliary winding of phase A, and the second secondary winding of phase A is 250:10:10:1.

[0128] The turns ratio of the primary winding of phase B, the first secondary winding of phase B, the auxiliary winding of phase B, and the second secondary winding of phase B is 250:10:10:1.

[0129] The turns ratio of the primary winding of phase C, the first secondary winding of phase C, the auxiliary winding of phase C, and the second secondary winding of phase C is 250:10:10:1.

[0130] In one embodiment, it further includes: a first converter and a second converter;

[0131] The first converter is connected to the three-phase auxiliary winding;

[0132] The second converter is connected to the first three-phase secondary winding and the second three-phase secondary winding;

[0133] The first converter and the second converter are connected by a capacitor assembly.

[0134] It should be noted that the first converter is an AC-to-DC converter, used to convert AC power into DC power.

[0135] The second converter is a DC-to-AC converter, used to convert DC power into AC power.

[0136] In one example, the first converter is a series converter.

[0137] It should be noted that a series converter is a voltage-type AC-to-DC converter connected in series in the power distribution line. It is connected in series with a hybrid distribution transformer and outputs a compensation voltage to offset voltage disturbances in the distribution network, stabilizing the supply voltage of sensitive AC loads on the low-voltage side. For example, when the medium-voltage grid experiences a 10% overvoltage, the series converter can output a reverse negative voltage to offset the voltage rise; when the grid experiences a 10% undervoltage, it outputs a positive positive voltage to compensate for the voltage drop. It can also be used to suppress harmonic voltages in the distribution network and reduce voltage distortion.

[0138] In this embodiment, by setting the positions of the windings of the same phase in the three-phase auxiliary winding and the three-phase primary winding to not form an axisymmetric distribution, the maximum magnetic flux of the intermediate yoke is reduced to 1.732 times that of the single-phase excitation magnetic flux, which is adapted to the working characteristics of the series converter and structurally reduces the risk of magnetic flux saturation of the hybrid distribution transformer.

[0139] In one example, the second converter is a parallel converter.

[0140] It should be noted that the parallel converter is a current-type DC-to-AC converter connected in parallel to the low-voltage distribution network side. It is the core component of the hybrid distribution transformer for current-type power quality management. It can adopt a hybrid topology of passive compensation and active compensation, and work synergistically with the series converter. For example, the series converter can be used to regulate voltage, and the parallel converter can be used to regulate current.

[0141] In one example, the parallel converter can adopt a modular design, support multi-unit parallel expansion, and have overload, overcurrent, and overtemperature protection functions.

[0142] In a simulation application example, the effects of a hybrid distribution transformer provided by an embodiment of the present invention will be explained.

[0143] In this application example, according to Figure 1 The provided structure of the hybrid distribution transformer was used to build a simulation platform for the hybrid distribution transformer using electronic circuit simulation software. The simulation platform was then used to perform simulations based on the operating conditions and relevant parameters in Table 1. Furthermore, according to... Figure 3 A corresponding simulation model of the structure of the hybrid distribution transformer shown (hereinafter referred to as the reference hybrid distribution transformer) was built for comparative experiments.

[0144] Table 1 is shown below:

[0145] Table 1. Given operating conditions and related parameters

[0146]

[0147] The simulation results obtained are as follows: Figures 5 to 8 As shown.

[0148] Figure 5 and Figure 6 The three phases v are shown respectively. ix When the overvoltage is 10%, the magnetic flux corresponding to the primary winding, auxiliary winding, and intermediate yoke of the reference hybrid distribution transformer and the hybrid distribution transformer provided by this invention, as well as the output voltage of the a-phase winding, are shown in these two figures. It can be seen that the structures of both hybrid distribution transformers can ensure the stability of the secondary output voltage. However, at this time, the magnetic flux of the intermediate yoke of the reference hybrid distribution transformer is twice that generated by single-phase excitation, while the magnetic flux of the intermediate yoke of the hybrid distribution transformer provided by this invention is only one time that generated by single-phase excitation.

[0149] Figure 7 and Figure 8 These respectively demonstrate the three-phase v ix When the voltage drops by 10%, the magnetic flux corresponding to the primary winding, auxiliary winding, and intermediate yoke of the reference hybrid distribution transformer and the hybrid distribution transformer provided by this invention, as well as the output voltage of the a-phase winding, are compared. Based on these two figures, it can be seen that both types of hybrid distribution transformers can ensure the stability of the secondary output voltage. Although the magnetic flux of the intermediate yoke of the reference hybrid distribution transformer is almost zero at this time, the maximum magnetic flux of the intermediate yoke of the hybrid distribution transformer provided by this invention is 1.732 times that of the magnetic flux generated by single-phase excitation, which is less than... Figure 5 Twice the working condition shown.

[0150] As can be seen from the above, the hybrid distribution transformer provided by the present invention is based on the core transformer basic architecture. By integrating the upper yoke of the primary excitation branch and the lower yoke of the auxiliary excitation branch, the deep integration of the magnetic circuit and the winding is achieved, which reduces the maximum magnetic flux density of the intermediate yoke of the hybrid distribution transformer to 86.6% of the original design, thereby significantly reducing the amount of core material used and the overall loss. While improving the magnetic circuit efficiency, it further reduces the equipment size and manufacturing cost, and has high engineering application value.

[0151] In one embodiment, the present invention also provides a power distribution system, including: a first AC power grid, a second AC power grid, and a hybrid power distribution transformer as described in any of the above embodiments;

[0152] The three-phase lines of the first AC power grid are connected to the three-phase primary windings of the hybrid distribution transformer;

[0153] The three-phase lines of the second AC power grid are connected to the first three-phase secondary windings and the second three-phase secondary windings of the hybrid distribution transformer.

[0154] The voltage level of the second AC power grid is lower than that of the first AC power grid.

[0155] It should be noted that the first AC power grid is the primary AC power grid, and the second AC power grid is the secondary AC power grid. The voltage level of the first AC power grid is higher than that of the second AC power grid.

[0156] In one embodiment, such as Figure 4 As shown, the first AC power grid can be a 10kV medium-voltage AC (MVAC) power grid. The second AC power grid can be a 400V low-voltage AC (LVAC) distribution network.

[0157] In one embodiment, the second AC power grid includes an AC microgrid, a PCS, and a sensitive AC load.

[0158] It should be noted that an AC microgrid is a small, modular AC power distribution system centered on distributed renewable energy sources (photovoltaics, wind power, etc.), combined with energy storage devices, AC loads, and power electronic conversion equipment. It serves as the core carrier for distribution substations to accept distributed power sources and is a crucial component in upgrading traditional distribution networks to smart distribution networks. It possesses dual operation modes: in grid-connected mode, it acts as a controlled unit within the distribution network, supplying power to the substation or absorbing power from the grid; in islanded mode, it can independently supply power to critical loads within the substation, improving power supply reliability. In practical applications of distribution substations, AC microgrids are deployed close to the load side.

[0159] A PCS (Power Conversion System) is the core power electronic interface device between an energy storage system and an AC microgrid / distribution network. It is also a key component for energy regulation and auxiliary power quality management in a distribution substation. It mainly consists of a DC / AC bidirectional converter, a core control unit, and protection modules. Its core function is to achieve bidirectional conversion of AC and DC energy and precisely control the charging and discharging process of the energy storage battery according to the operational needs of the distribution substation: during charging, it converts the AC power from the distribution network / AC microgrid into DC power for storage in the battery; during discharging, it converts the DC power from the battery into AC power conforming to grid standards, which is then transmitted to the distribution network or directly supplies power to the load. In this embodiment, the PCS functions in deep synergy with the hybrid distribution transformer provided by this invention. For example, it can be used to smooth power fluctuations, offset the randomness of renewable energy output in AC microgrids, stabilize the node power of the distribution transformer area, and reduce the voltage regulation pressure of the hybrid distribution transformer; it can be used for peak shaving and valley filling, i.e., discharging power during peak hours and charging energy storage during off-peak hours to optimize the load curve of the distribution transformer area; it can be used to assist in power quality management, i.e., to achieve reactive power compensation within the capacity range, and improve the power factor of the distribution transformer area in conjunction with the first and second converters of the hybrid distribution transformer; it can be used for islanded power supply support, i.e., when the distribution network fails, it can cooperate with the hybrid distribution transformer to achieve islanded mode switching and provide continuous power supply to sensitive AC loads. At the same time, the PCS can communicate with the battery management system (BMS) and the distribution network dispatching system through interfaces such as CAN and RS485 to achieve protective charging and discharging and intelligent control, ensuring the safe operation of the distribution transformer area.

[0160] Sensitive AC loads refer to AC electrical equipment / loads that have stringent requirements for power quality indicators. They are also the core service targets of the hybrid distribution transformer in this invention. Their normal operation is highly dependent on a stable and clean power supply. If the power quality indicators deviate from national standards, problems such as abnormal operation, data deviation, equipment damage, and even production interruption will occur. Typical sensitive AC loads in distribution transformer areas include: CNC machine tools and semiconductor production equipment in the precision manufacturing field; data center servers and communication base stations in the data communication field; MRI, CT and other imaging diagnostic equipment in the medical field; and electric vehicle charging piles and photovoltaic inverters in the new energy field.

[0161] Please see Figure 9 , Figure 9 A flowchart illustrating an integration method for a hybrid distribution transformer provided in an embodiment of the present invention.

[0162] This invention provides an integration method for a hybrid distribution transformer, applicable to any of the hybrid distribution transformers provided in the above embodiments. The integration method includes:

[0163] 101. Obtain the location setup plan, which includes the structure of the main transformer, the structure of the auxiliary transformer, the relative positions of the main transformer and the auxiliary transformer, the winding positions of the three-phase primary windings, the winding positions of the first and third-phase secondary windings, the winding positions of the second and third-phase secondary windings, and the winding positions of the three-phase auxiliary windings.

[0164] It should be noted that the location setup plan is pre-set according to the structure of the hybrid distribution transformer, which includes the structure of the main transformer, the structure of the auxiliary transformer, the relative positions of the main transformer and the auxiliary transformer, the winding positions of the three-phase primary windings, the winding positions of the first and third-phase secondary windings, the winding positions of the second and third-phase secondary windings, and the winding positions of the three-phase auxiliary windings.

[0165] Understandably, in the actual construction process, the location construction plan may also include the information required for construction, such as the specific number of turns and winding direction of the three-phase primary winding, the first three-phase secondary winding, the second three-phase secondary winding, and the three-phase auxiliary winding.

[0166] 102. Based on the location and construction plan, construct the main transformer and auxiliary transformer, and wind the three-phase primary winding and the first three-phase secondary winding onto the main transformer, and wind the second three-phase secondary winding and the three-phase auxiliary winding onto the auxiliary transformer.

[0167] It should be noted that since the preset location construction plan contains the information required for construction, the construction of the hybrid distribution transformer can be realized according to the location construction plan during the actual construction process.

[0168] Understandably, the order in which the main transformer and auxiliary transformer are installed—wound the three-phase primary winding and the first three-phase secondary winding onto the main transformer, and the second three-phase secondary winding and the three-phase auxiliary winding onto the auxiliary transformer—can be adjusted according to the actual situation.

[0169] For example:

[0170] In one alternative implementation, a main transformer and an auxiliary transformer can be constructed first, forming a shared intermediate yoke between them to create the main framework of the hybrid distribution transformer. Then, based on the winding position conditions that the magnetic core columns of the three-phase primary winding, the first three-phase secondary winding, the second three-phase secondary winding, and the three-phase auxiliary winding need to meet (i.e., the three-phase primary winding and the three-phase auxiliary winding do not form an axisymmetric distribution), the three-phase primary winding and the first three-phase secondary winding are wound on the magnetic core column of the main transformer, and the three-phase auxiliary winding and the second three-phase secondary winding are wound on the magnetic core column of the auxiliary transformer. Finally, one end of the windings of the same phase in the first three-phase secondary winding and the second three-phase secondary winding are connected to complete the construction of the hybrid distribution transformer.

[0171] See Figure 10 , Figure 10 This is a structural block diagram of an integrated device for a hybrid power distribution transformer provided in an embodiment of the present invention.

[0172] An integrated device for a hybrid distribution transformer provided in this embodiment of the invention includes:

[0173] The acquisition module 301 is used to acquire the location construction scheme, which includes the structure of the main transformer, the structure of the auxiliary transformer, the relative positions of the main transformer and the auxiliary transformer, the winding positions of the three-phase primary winding, the winding positions of the first three-phase secondary winding, the winding positions of the second three-phase secondary winding, and the winding positions of the three-phase auxiliary winding.

[0174] It should be noted that the location setup plan is pre-set according to the structure of the hybrid distribution transformer, which includes the structure of the main transformer, the structure of the auxiliary transformer, the relative positions of the main transformer and the auxiliary transformer, the winding positions of the three-phase primary windings, the winding positions of the first and third-phase secondary windings, the winding positions of the second and third-phase secondary windings, and the winding positions of the three-phase auxiliary windings.

[0175] Understandably, in the actual construction process, the location construction plan may also include the information required for construction, such as the specific number of turns and winding direction of the three-phase primary winding, the first three-phase secondary winding, the second three-phase secondary winding, and the three-phase auxiliary winding.

[0176] Module 302 is used to build the main transformer and auxiliary transformer according to the location construction plan, and to wind the three-phase primary winding and the first three-phase secondary winding onto the main transformer, and wind the second three-phase secondary winding and the three-phase auxiliary winding onto the auxiliary transformer.

[0177] It should be noted that since the preset location construction plan contains the information required for construction, the hybrid distribution transformer can be constructed according to the location construction plan during the actual construction process.

[0178] Understandably, the order in which the main transformer and auxiliary transformer are installed—wound the three-phase primary winding and the first three-phase secondary winding onto the main transformer, and the second three-phase secondary winding and the three-phase auxiliary winding onto the auxiliary transformer—can be adjusted according to the actual situation.

[0179] For example:

[0180] In one alternative implementation, a main transformer and an auxiliary transformer can be constructed first, forming a shared intermediate yoke between them to create the main framework of the hybrid distribution transformer. Then, based on the winding position conditions that the magnetic core columns of the three-phase primary winding, the first three-phase secondary winding, the second three-phase secondary winding, and the three-phase auxiliary winding need to meet (i.e., the three-phase primary winding and the three-phase auxiliary winding do not form an axisymmetric distribution), the three-phase primary winding and the first three-phase secondary winding are wound on the magnetic core column of the main transformer, and the three-phase auxiliary winding and the second three-phase secondary winding are wound on the magnetic core column of the auxiliary transformer. Finally, one end of the windings of the same phase in the first three-phase secondary winding and the second three-phase secondary winding are connected to complete the construction of the hybrid distribution transformer.

[0181] Please see Figure 11 , Figure 11 This is a structural block diagram of an electronic device provided in an embodiment of the present invention.

[0182] This invention provides an electronic device 40, which includes a processor 42 and a memory 44;

[0183] Memory 44 is used to store program code and transfer program code to processor 42;

[0184] The processor 42 is used to execute the method of the above embodiment according to the instructions in the program code.

[0185] It should be noted that the electronic device 40 in this embodiment may include one or more of the following components: processor 42, memory 44, and one or more application programs, wherein the one or more application programs may be stored in memory 44 and configured to be executed by one or more processors 42, and the one or more application programs are configured to perform the methods described in the above embodiment of the integrated method for hybrid distribution transformers.

[0186] Processor 42 may include one or more processing cores. Processor 42 connects to various parts within the electronic device 40 using various interfaces and lines, and performs various functions and processes data of the electronic device 40 by running or executing instructions, programs, code sets, or instruction sets stored in memory 44, and by calling data stored in memory 44. Optionally, processor 42 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). Processor 42 may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the displayed content; and the modem handles wireless communication. It is understood that the modem may also not be integrated into processor 42 and may be implemented separately using a communication chip.

[0187] The memory 44 may include random access memory (RAM) or read-only memory (ROM). The memory 44 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 44 may include a program storage area and a data storage area. The program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (such as touch functionality, sound playback functionality, image playback functionality, etc.), and instructions for implementing the various method embodiments described below. The data storage area may also store data created by the electronic device 40 during use.

[0188] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0189] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0190] Furthermore, in the various embodiments of the present invention, the functional units can be integrated into one processing unit, or each functional unit can be a separate physical entity, or two or more functional units can be integrated into one processing unit. The integrated unit described above can be implemented in hardware or as a software functional unit.

[0191] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0192] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0193] It should also be noted that in the description of this invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0194] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hybrid distribution transformer, characterized in that, include: Main transformer, auxiliary transformer, three-phase primary winding, first three-phase secondary winding, second three-phase secondary winding and three-phase auxiliary winding; The yoke of the main transformer near the auxiliary transformer, or the yoke of the auxiliary transformer near the main transformer, forms the intermediate yoke of the hybrid distribution transformer; The first three-phase secondary winding is wound on the side of the main transformer near the intermediate yoke; The three-phase primary winding is wound on the side of the main transformer away from the intermediate yoke; The second and third phase secondary windings are wound on the side of the auxiliary transformer closest to the intermediate yoke; The three-phase auxiliary winding is wound on the side of the auxiliary transformer away from the intermediate yoke; In the three-phase auxiliary winding and the three-phase primary winding, the windings of the same phase are not axially symmetrically distributed. In the first three-phase secondary winding and the second three-phase secondary winding, one end of the windings of the same phase is connected to each other.

2. The hybrid distribution transformer according to claim 1, characterized in that, The first three-phase secondary winding includes a first A-phase secondary winding, a first B-phase secondary winding, and a first C-phase secondary winding; the second three-phase secondary winding includes a second A-phase secondary winding, a second B-phase secondary winding, and a second C-phase secondary winding. The same-name terminal of the first phase A secondary winding is connected to the opposite-name terminal of the second phase A secondary winding; The same-name terminal of the first phase B secondary winding is connected to the opposite-name terminal of the second phase B secondary winding; The same-name terminal of the first C-phase secondary winding is connected to the opposite-name terminal of the second C-phase secondary winding.

3. The hybrid distribution transformer according to claim 2, characterized in that, The core column of the main transformer is made of the same material as the core column of the auxiliary transformer. The cross-sectional area of ​​the magnetic core column of the main transformer is the same as that of the magnetic core column of the auxiliary transformer.

4. The hybrid distribution transformer according to claim 3, characterized in that, The turns ratio of the three-phase primary winding, the first three-phase secondary winding, the three-phase auxiliary winding, and the second three-phase secondary winding satisfies 250:10:10:

1.

5. The hybrid distribution transformer according to claim 4, characterized in that, The main transformer and the auxiliary transformer are core-type transformers.

6. The hybrid distribution transformer according to claim 5, characterized in that, Also includes: First converter and second converter; The first converter is connected to the three-phase auxiliary winding; The second converter is connected to the first three-phase secondary winding and the second three-phase secondary winding; The first converter and the second converter are connected by a capacitor assembly.

7. A power distribution system, characterized in that, include: The first AC power grid, the second AC power grid, and the hybrid distribution transformer as described in any one of claims 1-6; The three-phase lines of the first AC power grid are connected to the three-phase primary windings of the hybrid distribution transformer; The three-phase lines of the second AC power grid are connected to the first three-phase secondary winding and the second three-phase secondary winding of the hybrid distribution transformer; The voltage level of the second AC power grid is lower than that of the first AC power grid.

8. An integration method for a hybrid distribution transformer, characterized in that, The integration method, applied to the hybrid distribution transformer as described in any one of claims 1-6, comprises: Obtain a location setup plan, which includes the structure of the main transformer, the structure of the auxiliary transformer, the relative positions of the main transformer and the auxiliary transformer, the winding positions of the three-phase primary windings, the winding positions of the first three-phase secondary windings, the winding positions of the second three-phase secondary windings, and the winding positions of the three-phase auxiliary windings. According to the aforementioned location construction plan, the main transformer and the auxiliary transformer are constructed, and the three-phase primary winding and the first three-phase secondary winding are wound on the main transformer, while the second three-phase secondary winding and the three-phase auxiliary winding are wound on the auxiliary transformer.

9. An integrated device for a hybrid distribution transformer, characterized in that, include: The acquisition module is used to acquire the location construction plan, which includes the structure of the main transformer, the structure of the auxiliary transformer, the relative positions of the main transformer and the auxiliary transformer, the winding positions of the three-phase primary windings, the winding positions of the first three-phase secondary windings, the winding positions of the second three-phase secondary windings, and the winding positions of the three-phase auxiliary windings. The module is used to construct the main transformer and the auxiliary transformer according to the location construction plan, and to wind the three-phase primary winding and the first three-phase secondary winding onto the main transformer, and to wind the second three-phase secondary winding and the three-phase auxiliary winding onto the auxiliary transformer.

10. An electronic device, characterized in that, The device includes a processor and a memory; The memory is used to store program code and transmit the program code to the processor; The processor is configured to execute the method as described in claim 8 according to instructions in the program code.

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