Phase compensation method and system of transformer
By obtaining the phase errors of the power grid and distribution network, determining the connection group of the phase compensation device, and adjusting the phase at 30° intervals, the problem of slow adjustment speed and low accuracy in phase lock loop technology is solved, and fast response is achieved and high-precision phase compensation.
Patent Information
- Application Number
- CN202411568072.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-05
- Publication Date
- 2025-02-14
AI Technical Summary
The existing phase-locked loop technology has problems of slow adjustment speed and low accuracy during the pressure regulation process, especially when large-angle phase adjustment is required.
By obtaining the phase errors of the power grid bus voltage and the distribution network bus voltage, the connection group of the phase compensation device is determined, and the phase is adjusted at one interval of 30° through different connection groups to achieve phase compensation.
It achieves the effect of fast frequency tracking speed, short response time and high phase adjustment accuracy, and provides a signal source for the same frequency and phase withstand voltage test.
Smart Images
Figure CN119438696A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of voltage phase compensation, and in particular to a transformer phase compensation method and system. Background Art
[0002] With the acceleration of infrastructure construction in my country, the capacity of the power system has grown rapidly. Before the equipment is put into operation, an AC withstand voltage test is required, otherwise the insulation of the equipment cannot be guaranteed, which will affect the stable operation of the power system. However, breakdown accidents may occur during the AC withstand voltage test, and the resulting VFTO will seriously threaten the safety of the tested equipment and the operating equipment. In order to ensure the safety and reliability of the withstand voltage test, the test voltage needs to reach the "same frequency and same phase", but the voltage used for the test will be affected by the connection groups of the power transformer and the distribution transformer in the power system, resulting in a phase difference of N×30°.
[0003] The current voltage regulation technology mainly uses the same frequency and same phase control box to compare the bus voltage signal with the test voltage signal, and uses the phase-locked loop technology to achieve real-time dynamic tracking of frequency and phase. Since the whole set of technology uses a large number of power electronic devices, there are problems such as high cost. The existing phase-locked loop technology is based on the principle of negative feedback regulation, which controls the power supply to output different voltage phases to achieve the purpose of phase regulation. However, the phase adjustment and frequency tracking speed of the phase-locked loop will be affected by system interference, resulting in slow adjustment speed. When large-angle phase adjustment is required, there is a problem of low accuracy. Summary of the invention
[0004] In order to at least to some extent overcome the problems of slow adjustment speed and low precision in the voltage regulation method in the related art, the present application provides a phase compensation method and system for a transformer.
[0005] The scheme of this application is as follows:
[0006] According to a first aspect of an embodiment of the present application, a phase compensation method for a transformer is provided, comprising:
[0007] Obtaining the power grid bus voltage and the distribution network bus voltage, and calculating the phase error between the power grid bus voltage and the distribution network bus voltage;
[0008] Determine the connection group of the phase compensation device according to the phase error between the power grid bus voltage and the distribution network bus voltage;
[0009] Performing phase compensation through a phase compensation device according to the determined connection group, and recalculating the phase error between the power grid bus voltage and the distribution network bus voltage;
[0010] Determine whether the phase error between the power grid bus voltage and the distribution network bus voltage is less than a preset threshold;
[0011] If the phase error between the power grid bus voltage and the distribution network bus voltage is less than a preset threshold, the adjustment is terminated;
[0012] The phase compensation device adjusts the phase at intervals of 30° through different connection groups.
[0013] Preferably, the method further comprises:
[0014] If the phase error between the grid bus voltage and the distribution network bus voltage is not less than the preset threshold, the connection group of the phase compensation device is re-determined and adjusted again until the phase error between the grid bus voltage and the distribution network bus voltage is less than the preset threshold.
[0015] Preferably, the phase compensation device includes 12 ports, and N×30° voltage regulators of different connection models are formed by connecting different ports;
[0016] Wherein, N is an integer.
[0017] Preferably, when the primary and secondary connections of the three-phase winding of the phase compensation device are both star-connected, the primary and secondary phases are adjusted at intervals of 60°.
[0018] Preferably, when the primary connection and the secondary connection of the three-phase winding of the phase compensation device are both star-connected, three positive connection modes and three reverse connection modes are included;
[0019] The connection groups of the three positive connection methods are Yy0, Yy4 and Yy8;
[0020] The connection groups of the three reverse connection methods are Yy10, Yy6 and Yy2.
[0021] Preferably, when the primary connection of the three-phase winding of the phase compensation device is a star connection and the secondary connection is a triangle connection, the primary and secondary phases are adjusted at intervals of 60°.
[0022] Preferably, when the primary connection of the three-phase winding of the phase compensation device is a star connection and the secondary connection is a triangle connection, three positive connection modes and three reverse connection modes are included;
[0023] The connection groups of the three orthogonal connection methods are Yd11, Yd3, and Yd7;
[0024] The connection groups of the three reverse connection methods are Yd1, Yd5 and Yd9.
[0025] Preferably, the power grid bus voltage is a reference signal for phase regulation, and the distribution network bus voltage reflects the voltage phase of the actual power system.
[0026] Preferably, the grid bus voltage is an integer multiple of 30.
[0027] According to a second aspect of an embodiment of the present application, a phase compensation system for a transformer is provided, comprising:
[0028] A processor, a memory and a phase compensation device;
[0029] The processor is connected to the memory and the phase compensation device via a communication bus:
[0030] Wherein, the processor is used to call and execute the program stored in the memory;
[0031] The memory is used to store a program, wherein the program is at least used to execute a transformer phase compensation method as described in any one of the above items;
[0032] The phase compensation device is used to perform phase compensation by adjusting the connection groups.
[0033] The technical solution provided by the present application may include the following beneficial effects: The phase compensation method of the transformer in the present application includes: obtaining the grid bus voltage and the distribution network bus voltage, and calculating the phase error between the grid bus voltage and the distribution network bus voltage; determining the connection group of the phase compensation device according to the phase error between the grid bus voltage and the distribution network bus voltage; performing phase compensation through the phase compensation device according to the determined connection group, and recalculating the phase error between the grid bus voltage and the distribution network bus voltage; determining whether the phase error between the grid bus voltage and the distribution network bus voltage is less than a preset threshold; if the phase error between the grid bus voltage and the distribution network bus voltage is less than the preset threshold, ending the adjustment; wherein the phase compensation device adjusts the phase at intervals of 30° through different connection groups.
[0034] In this technical solution, voltage signals are extracted from the power grid and distribution network. Different phase compensation devices are connected to different groups for different phase errors, and different phase adjustment schemes are selected to achieve the advantages of fast frequency tracking speed, short response time, and high phase adjustment accuracy, and also provide a signal source for the same frequency and same phase withstand voltage test.
[0035] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.
[0037] Figure 1 It is a flowchart of a phase compensation method of a transformer provided by an embodiment of the present application;
[0038] Figure 2is a schematic diagram of a circuit architecture of a transformer phase compensation method provided by another embodiment of the present application when being implemented;
[0039] Figure 3 This is a schematic diagram of an interface of a phase compensation device provided by an embodiment of the present application;
[0040] Figure 4 is an interface schematic diagram of another phase compensation device provided by an embodiment of the present application;
[0041] Figure 5 This is a schematic diagram of a wiring method of a phase compensation device provided by an embodiment of the present application;
[0042] Figure 6 This is a schematic diagram of another wiring method of a phase compensation device provided by an embodiment of the present application;
[0043] Figure 7 This is a schematic diagram of a wiring method of another phase compensation device provided by an embodiment of the present application;
[0044] Figure 8 This is a schematic diagram of a wiring method of another phase compensation device provided by an embodiment of the present application;
[0045] Fig. 9 It is a structural schematic diagram of a phase compensation system of a transformer provided in an embodiment of the present application.
[0046] Reference numerals: processor-21; memory-22; phase compensation device-23. DETAILED DESCRIPTION
[0047] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.
[0048] Embodiment 1
[0049] Figure 1 is a flow chart of a transformer phase compensation method provided by an embodiment of the present application, referring to Figure 1 , a transformer phase compensation method, comprising:
[0050] S11: Obtain the power grid bus voltage and the distribution network bus voltage, and calculate the phase error between the power grid bus voltage and the distribution network bus voltage;
[0051] It should be noted that the grid bus voltage is a reference signal for phase regulation, and the distribution network bus voltage reflects the voltage phase of the actual power system.
[0052] In this embodiment, the grid bus voltage is an integer multiple of 30.
[0053] The power grid refers to the whole of the power system consisting of substations and transmission and distribution lines of various voltages, which are responsible for transmitting and distributing electric energy and changing voltage. It includes three units: substation, transmission and distribution, and the voltage levels range from ultra-high voltage to low voltage.
[0054] The distribution network refers to the power grid that receives electric energy from the transmission network or regional power plants and distributes it locally or step by step according to voltage to various users through distribution facilities. It consists of overhead lines, cables, poles, distribution transformers, etc., and is responsible for distributing the electric energy transmitted in the transmission network to the user's electrical equipment.
[0055] S12: determining a connection group of the phase compensation device according to a phase error between the power grid bus voltage and the distribution network bus voltage;
[0056] S13: performing phase compensation through a phase compensation device according to the determined connection group, and recalculating the phase error between the power grid bus voltage and the distribution network bus voltage;
[0057] S14: Determine whether the phase error between the power grid bus voltage and the distribution network bus voltage is less than a preset threshold;
[0058] In specific practice, the preset threshold is set to 15°.
[0059] S15: If the phase error between the power grid bus voltage and the distribution network bus voltage is less than a preset threshold, the adjustment is terminated;
[0060] The phase compensation device adjusts the phase at intervals of 30° through different connection groups.
[0061] It should be noted that the method also includes:
[0062] If the phase error between the grid bus voltage and the distribution network bus voltage is not less than the preset threshold, the connection group of the phase compensation device is re-determined and adjusted again until the phase error between the grid bus voltage and the distribution network bus voltage is less than the preset threshold.
[0063] It should be noted that, refer to Figure 2The AC withstand voltage test extracts the voltage signal from the distribution network bus, and after the voltage is boosted by the test transformer and the series resonant device, the withstand voltage test is carried out on the GIS maintenance interval. However, under actual application conditions on site, the standard connection groups of three-phase three-winding transformers are generally YNyn0d11 and YNyn0y0 (high voltage / medium voltage / low voltage). The standard connection groups of double-winding transformers are Yyn0, Yd11, YNd11, YNy0, Yy0 (high voltage / low voltage). Table 1 below shows the phase relationship between the reference potential Um∠Φm and the adjustment potential U1∠Φ1. (The data in the table are the angles of Φ1 leading Φm under different three-phase three-winding and double winding conditions)
[0064] Table 1:
[0065] Yyn0 Yd11 YNhd Yj Y Yj YNyn0y0 0 60 60 0 0 YNyn0d11 30 60 60 30 30
[0066] When both the three-winding transformer and the two-winding step-down distribution transformer adopt standard connection groups, there are only three situations for the relationship between Φ1 and Φm: Φ1 leads Φm (30°); Φ1 and Φm maintain the same phase; Φ1 leads Φm by 60°.
[0067] Under special circumstances, the phase difference between the reference potential Um∠Φm and the adjustment potential U1∠Φ1 may be N×30° (N is a positive integer).
[0068] It should be noted that the connection group of the transformer generally uses capital letters to represent the wiring method of the primary side (or primary side), and uses lowercase letters to represent the wiring method of the secondary side (or secondary side). Among them, Y (or y) represents star connection, N represents neutral line, and D (or d) represents delta connection. The numbers are represented by clock method to represent the phase relationship between the primary and secondary line voltages. In this representation method, the primary line voltage phasor serves as the minute hand, pointing to the 12 o'clock position of the clock; the secondary line voltage phasor serves as the hour hand, pointing to the corresponding number. For example, in "YNyn0", "YN" indicates that the primary side is a star connection with a neutral line, where Y represents star and N represents neutral line; "yn0" indicates that the secondary side winding is a star connection with a neutral line, where Y represents star, n represents neutral line, and 0 represents that the neutral line is grounded. There is another secondary winding connection method called "d11", where "d" means the secondary side is a delta connection; and "11" means the line voltage Uab on the secondary side of the transformer lags the primary side line voltage UAB by 330°.
[0069] It should be noted that the phase compensation device includes 12 ports, and N×30° voltage regulators of different connection models are formed by connecting different ports;
[0070] Wherein, N is an integer.
[0071] In this technical solution, the phase is adjusted at intervals of 30° by using different connection group numbers. The phase shifter has 12 interfaces, such as Figure 3 as well as Figure 4 shown.
[0072] It should be noted that when the primary and secondary connections of the three-phase winding of the phase compensation device are both star-connected, the primary and secondary phases are adjusted at intervals of 60°.
[0073] When the primary and secondary connections of the three-phase winding of the phase compensation device are both star-connected, there are three positive connection methods and three reverse connection methods;
[0074] The connection groups of the three positive connection methods are Yy0, Yy4 and Yy8;
[0075] The connection groups of the three reverse connection methods are Yy10, Yy6 and Yy2.
[0076] When the connections on both sides of the three-phase winding are star-connected, there are 6 connection methods, which can adjust the primary and secondary phases at intervals of 60°. The three connection methods of positive connection are as follows: Figure 5 shown.
[0077] Figure 5 In the equation, A, B, and C are primary sides, a, b, and c are secondary sides, and A→B→C→A is the positive direction. If the phase of phase A is 0°, then The phase voltage and line voltage differences of the three types of Yy formal connections are shown in Table 2:
[0078] Table 2Yy positive connection line, phase voltage difference
[0079]
[0080]
[0081] If the secondary sides of Yy0, Yy4, and Yy8 are connected in reverse, Yy6, Yy10, and Yy2 will be obtained. Figure 6 shown.
[0082] Figure 6 In the equation, A, B, and C are primary sides, a, b, and c are secondary sides, and A→B→C→A is the positive direction. If the phase of phase A is 0°, then The phase voltage and line voltage differences of three types of Yy reverse connection are shown in Table 3:
[0083] Table 3Yy reverse connection line, phase voltage difference
[0084]
[0085] It should be noted that when the primary connection of the three-phase winding of the phase compensation device is a star connection and the secondary connection is a triangle connection, the primary and secondary phases are adjusted at intervals of 60°.
[0086] When the primary connection of the three-phase winding of the phase compensation device is a star connection and the secondary connection is a triangle connection, there are 3 positive connection methods and 3 reverse connection methods;
[0087] The connection groups of the three orthogonal connection methods are Yd11, Yd3, and Yd7;
[0088] The connection groups of the three reverse connection methods are Yd1, Yd5 and Yd9.
[0089] It should be noted that if it is from Yd1 to Yd2, the adjustment interval is 30°, and if it is from Yd1 to Yd3, the adjustment interval is 60°.
[0090] In this technical solution, the primary and secondary connections are both star-connected, providing six connection groups, namely Yy0, Yy4, Yy8, Yy10, Yy6 and Yy2. Then, the primary connection is star-connected and the secondary connection is triangle-connected, providing six connection groups, namely Yd1, Yd5, Yd9, Yd11, Yd3 and Yd7, to compensate for the phase that cannot be adjusted by the Yy connection.
[0091] The secondary side can be connected in a certain order to obtain Yd11, Yd3 and Yd7 connections. The connection group method and phase vector diagram are shown in the figure. Figure 7 shown.
[0092] Figure 7 In the equation, A, B, and C are primary sides, a, b, and c are secondary sides, and A→B→C→A is the positive direction. If the phase of phase A is 0°, then The phase voltage and line voltage differences of three types of Yd forward connection are shown in Table 4:
[0093] Table 4Yd forward connection line, phase voltage difference
[0094]
[0095] If the triangle connection order of the secondary side is reversed, three connection modes, Yd1, Yd5 and Yd9, can be obtained. The connection group method and phase vector diagram are shown in the figure. Figure 8 shown.
[0096] Figure 8 In the equation, A, B, and C are primary sides, a, b, and c are secondary sides, and A→B→C→A is the positive direction. If the phase of phase A is 0°, then The phase voltage and line voltage differences of three types of Yd reverse connection are shown in Table 5:
[0097] Table 5Yd reverse connection line, phase voltage difference
[0098]
[0099] When implementing this technical solution, the connection group of the phase compensation device is determined based on the calculated phase errors of the grid bus voltage and the distribution network bus voltage, and the correspondence between the phases and the connection groups in Tables 2 to 5 is compared, so that the phase difference between the adjusted voltage phase and the grid bus voltage is less than 15°.
[0100] In this technical solution, voltage signals are extracted from the power grid and distribution network. Different phase compensation devices are connected to different groups for different phase errors, and different phase adjustment schemes are selected to achieve the advantages of fast frequency tracking speed, short response time, and high phase adjustment accuracy, and also provide a signal source for the same frequency and same phase withstand voltage test.
[0101] Embodiment 2
[0102] A transformer phase compensation system, referring to Fig. 9 ,include:
[0103] Processor 21, memory 22 and phase compensation device 23;
[0104] The processor 21 is connected to the memory 22 and the phase compensation device 23 via a communication bus:
[0105] The processor 21 is used to call and execute the program stored in the memory 22;
[0106] A memory 22, used for storing a program, wherein the program is used for executing at least one of the transformer phase compensation methods in the above embodiments;
[0107] The phase compensation device 23 is used for performing phase compensation by adjusting the connection groups.
[0108] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.
[0109] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" refers to at least two.
[0110] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.
[0111] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.
[0112] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.
[0113] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.
[0114] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.
[0115] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.
[0116] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.
Claims
1. A transformer phase compensation method, characterized in that: include: Obtaining the power grid bus voltage and the distribution network bus voltage, and calculating the phase error between the power grid bus voltage and the distribution network bus voltage; Determine the connection group of the phase compensation device according to the phase error between the power grid bus voltage and the distribution network bus voltage; Performing phase compensation through a phase compensation device according to the determined connection group, and recalculating the phase error between the power grid bus voltage and the distribution network bus voltage; Determine whether the phase error between the power grid bus voltage and the distribution network bus voltage is less than a preset threshold; If the phase error between the power grid bus voltage and the distribution network bus voltage is less than a preset threshold, the adjustment is terminated; The phase compensation device adjusts the phase at intervals of 30° through different connection groups.
2. The method according to claim 1, characterized in that The method further comprises: If the phase error between the grid bus voltage and the distribution network bus voltage is not less than the preset threshold, the connection group of the phase compensation device is re-determined and adjusted again until the phase error between the grid bus voltage and the distribution network bus voltage is less than the preset threshold.
3. The method according to claim 1, characterized in that The phase compensation device includes 12 ports, and N×30° voltage regulators of different connection models are formed by connecting different ports; Wherein, N is an integer.
4. The method according to claim 3, characterized in that When the primary and secondary connections of the three-phase winding of the phase compensation device are both star-connected, the primary and secondary phases are adjusted at intervals of 60°.
5. The method according to claim 4, characterized in that When the primary connection and the secondary connection of the three-phase winding of the phase compensation device are both star-connected, there are three positive connection methods and three reverse connection methods; The connection groups of the three positive connection methods are Yy0, Yy4 and Yy8; The connection groups of the three reverse connection methods are Yy10, Yy6 and Yy2.
6. The method according to claim 3, characterized in that When the primary connection of the three-phase winding of the phase compensation device is a star connection and the secondary connection is a triangle connection, the primary and secondary phases are adjusted at intervals of 60 degrees.
7. The method according to claim 6, characterized in that When the primary connection of the three-phase winding of the phase compensation device is a star connection and the secondary connection is a triangle connection, there are three positive connection modes and three reverse connection modes; The connection groups of the three orthogonal connection methods are Yd11, Yd3, and Yd7; The connection groups of the three reverse connection methods are Yd1, Yd5 and Yd9.
8. The method according to claim 1, characterized in that: The power grid bus voltage is a reference signal for phase adjustment, and the distribution network bus voltage reflects the voltage phase of the actual power system.
9. The method according to claim 8, characterized in that The grid bus voltage is an integer multiple of 30.
10. A transformer phase compensation system, characterized in that: include: A processor, a memory and a phase compensation device; The processor is connected to the memory and the phase compensation device via a communication bus: Wherein, the processor is used to call and execute the program stored in the memory; The memory is used to store a program, and the program is used to execute at least a transformer phase compensation method according to any one of claims 1 to 9; The phase compensation device is used to perform phase compensation by adjusting the connection groups.