Method and device for determining short-circuit current of phase-shifting transformer

Abstract

The present application discloses a method and device for determining the short-circuit current of a phase-shifting transformer. By acquiring the electromagnetic constraint parameters and fault node information of the phase-shifting transformer and determining the fixed admittance matrix of the phase-shifting transformer based on the electromagnetic constraint parameters, the accuracy of determining the short-circuit current can be improved by using the equivalent circuit principle. Then, according to the fault node information, the fixed admittance matrix is ​​corrected to obtain a target admittance matrix to locate the fault node and obtain the admittance matrix after the fault. Finally, based on the target admittance matrix, the node voltage is calculated and the short-circuit current of the phase-shifting transformer is determined, so as to determine the short-circuit current of the phase-shifting transformer. At the same time, the method can be applied to the determination of the short-circuit current of a conventional transformer and has strong versatility.

Description

Technical Field

[0001] The present application relates to the field of circuit safety technology, and in particular to a method and device for determining a short-circuit current of a phase-shifting transformer. Background Art

[0002] As the power grid line current problem becomes increasingly prominent, the phase-shifting transformer is used more and more widely. The phase-shifting transformer body is connected by a series transformer (ST) and a parallel transformer (ET). The primary side connection of the series transformer is Ш-type connection, the secondary side connection of the series transformer is △-type connection, the primary and secondary sides of the parallel transformer are both Yn-type connection, and the secondary side of the parallel transformer and the secondary side of the series transformer are connected in three phases. Its complex connection structure is quite different from that of conventional transformers.

[0003] Since the phase-shifting transformer has a gear adjustment function, the relay protection configuration of the phase-shifting transformer is further different from that of the conventional power transformer, resulting in that the short-circuit current determination method of the conventional transformer cannot be applied to the phase-shifting transformer, especially the fault detection of asymmetric short circuit. Summary of the invention

[0004] The present application provides a method and device for determining the short-circuit current of a phase-shifting transformer, so as to solve the technical problem that the current short-circuit current determination method is not applicable to the phase-shifting transformer.

[0005] In order to solve the above technical problems, in a first aspect, an embodiment of the present application provides a method for determining a short-circuit current of a phase-shifting transformer, comprising:

[0006] Obtaining electromagnetic constraint parameters and fault node information of the phase-shifting transformer, where the electromagnetic constraint parameters are constraint parameters between equivalent impedance, node voltage, and node current of the phase-shifting transformer;

[0007] Based on the electromagnetic constraint parameters, a fixed admittance matrix of the phase-shifting transformer is determined, the fixed admittance matrix includes node admittances of multiple nodes of the phase-shifting transformer, and the fixed admittance matrix is ​​a parameter matrix that uses node voltages to represent node injection currents;

[0008] According to the fault node information, the fixed admittance matrix is ​​modified to obtain the target admittance matrix;

[0009] Based on the target admittance matrix, the short-circuit current of the phase-shifting transformer is determined.

[0010] This embodiment obtains the electromagnetic constraint parameters and fault node information of the phase-shifting transformer, and determines the fixed admittance matrix of the phase-shifting transformer based on the electromagnetic constraint parameters, so that the accuracy of determining the short-circuit current can be improved by using the equivalent circuit principle; then, according to the fault node information, the fixed admittance matrix is ​​corrected to obtain the target admittance matrix to locate the fault node and obtain the admittance matrix after the fault; finally, based on the target admittance matrix, the short-circuit current of the phase-shifting transformer is determined to achieve the determination of the short-circuit current of the phase-shifting transformer. At the same time, this method can be applied to the determination of the short-circuit current of a conventional transformer and has strong versatility.

[0011] In one embodiment, determining a fixed admittance matrix of a phase-shifting transformer based on electromagnetic constraint parameters includes:

[0012] Determining a first admittance matrix of a three-phase parallel transformer in a phase-shifting transformer according to electromagnetic constraint parameters;

[0013] Determining a second admittance matrix of a three-phase series transformer in a phase-shifting transformer according to electromagnetic constraint parameters;

[0014] The first admittance matrix and the second admittance matrix are combined and grounded to obtain a fixed admittance matrix.

[0015] Optionally, determining a first admittance matrix of a three-phase parallel transformer in a phase-shifting transformer according to electromagnetic constraint parameters includes:

[0016] Performing data replacement on electromagnetic constraint parameters to generate three first indefinite admittance matrices of the three-phase parallel transformer;

[0017] The three first indefinite admittance matrices are added to obtain a first admittance matrix.

[0018] Optionally, determining a second admittance matrix of a three-phase series transformer in a phase-shifting transformer according to electromagnetic constraint parameters includes:

[0019] Determine the voltage-current relationship of the three-phase series transformer based on the electromagnetic constraint parameters and the circuit connection mode of the phase-shifting transformer;

[0020] Performing data transformation on the voltage-current relationship, three second indefinite admittance matrices of the three-phase series transformer are obtained;

[0021] The three second indefinite admittance matrices are added to obtain a second admittance matrix.

[0022] Optionally, the first admittance matrix and the second admittance matrix are combined and grounded to obtain a fixed admittance matrix, including:

[0023] According to the connected nodes of the phase-shifting transformer, the first admittance matrix and the second admittance matrix are combined to obtain a third admittance matrix;

[0024] According to the circuit connection mode of the phase-shifting transformer, the grounding nodes in the third admittance matrix are grounded to obtain a fixed admittance matrix.

[0025] In one embodiment, the fault node information includes the fault node number and the short-circuit impedance value. According to the fault node information, the fixed admittance matrix is ​​corrected to obtain the target admittance matrix, including:

[0026] According to the short-circuit impedance value, the node admittance corresponding to the node number in the fixed admittance matrix is ​​corrected to obtain the target admittance matrix.

[0027] In one embodiment, determining the short-circuit current of the phase-shifting transformer based on the target admittance matrix includes:

[0028] Determine the target node voltage of the phase-shifting transformer based on the target admittance matrix and the node injection current;

[0029] The short-circuit current of the phase-shifting transformer is determined according to the target node voltage and electromagnetic constraint parameters.

[0030] In one embodiment, before obtaining the electromagnetic constraint parameters and fault node information of the phase-shifting transformer, the method further includes:

[0031] An equivalent circuit model of the phase-shifting transformer is established according to the first equivalent impedance of the three-phase parallel transformer and the second equivalent impedance of the three-phase series transformer of the phase-shifting transformer;

[0032] Based on the equivalent circuit model, the electromagnetic constraint parameters are determined.

[0033] In a second aspect, an embodiment of the present application provides a short-circuit current determination device for a phase-shifting transformer, comprising:

[0034] An acquisition module is used to acquire electromagnetic constraint parameters and fault node information of the phase-shifting transformer, where the electromagnetic constraint parameters are constraint parameters between the equivalent impedance, node voltage and node current of the phase-shifting transformer;

[0035] A first determination module is used to determine a fixed admittance matrix of a phase-shifting transformer based on electromagnetic constraint parameters, wherein the fixed admittance matrix includes node admittances of multiple nodes of the phase-shifting transformer, and the fixed admittance matrix is ​​a parameter matrix that uses node voltages to represent node injection currents;

[0036] A correction module is used to correct the fixed admittance matrix according to the fault node information to obtain the target admittance matrix;

[0037] The second determination module is used to determine the short-circuit current of the phase-shifting transformer based on the target admittance matrix.

[0038] In a second aspect, an embodiment of the present application provides a computer device, including a processor and a memory, the memory being used to store a computer program, and when the computer program is executed by the processor, the steps of the method for determining the short-circuit current of a phase-shifting transformer as in the first aspect are implemented.

[0039] It should be noted that for the beneficial effects of the second and third aspects, please refer to the relevant description of the first aspect, which will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 A schematic flow chart of a method for determining the short-circuit current of a phase-shifting transformer provided in an embodiment of the present application;

[0041] Figure 2 A schematic diagram of an equivalent circuit model and node numbering of a phase-shifting transformer provided in an embodiment of the present application;

[0042] Figure 3 A schematic diagram of an equivalent circuit of a three-phase parallel transformer provided in an embodiment of the present application;

[0043] Figure 4 Schematic diagram of the equivalent circuit of the three-phase series transformer provided in the embodiment of the present application

[0044] Figure 5 A schematic diagram of node merging of a series transformer and a parallel transformer provided in an embodiment of the present application;

[0045] Figure 6 A schematic diagram of a flow chart of a short-circuit current determination device for a phase-shifting transformer provided in an embodiment of the present application;

[0046] Figure 7 A schematic diagram of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] As recorded in relevant technologies, the complex connection structure of the phase-shifting transformer is quite different from that of the conventional transformer, and because the phase-shifting transformer has a gear adjustment function, the relay protection configuration of the phase-shifting transformer is further quite different from that of the conventional power transformer, resulting in that the short-circuit current determination method of the conventional transformer cannot be applied to the phase-shifting transformer, especially the fault detection of asymmetric short circuit.

[0049] To this end, an embodiment of the present application provides a method and device for determining the short-circuit current of a phase-shifting transformer, by obtaining the electromagnetic constraint parameters and fault node information of the phase-shifting transformer, and determining the fixed admittance matrix of the phase-shifting transformer based on the electromagnetic constraint parameters, so that the accuracy of determining the short-circuit current can be improved by using the equivalent circuit principle; then, according to the fault node information, the fixed admittance matrix is ​​corrected to obtain a target admittance matrix to locate the fault node and obtain the admittance matrix after the fault; finally, based on the target admittance matrix, the short-circuit current of the phase-shifting transformer is determined to achieve the determination of the short-circuit current of the phase-shifting transformer. At the same time, this method can be applied to the determination of the short-circuit current of conventional transformers and has strong versatility.

[0050] Please refer to Figure 1 , Figure 1 The flowchart of a method for determining the short-circuit current of a phase-shifting transformer provided in an embodiment of the present application is shown in FIG. The method for determining the short-circuit current of an embodiment of the present application can be applied to computer devices, including but not limited to smart phones, tablet computers, laptop computers, desktop computers, physical servers, and independent servers. Figure 1 As shown, the short-circuit current determination method includes steps S101 to S104, which are described in detail as follows:

[0051] Step S101, obtaining electromagnetic constraint parameters and fault node information of a phase-shifting transformer, wherein the electromagnetic constraint parameters are constraint parameters between equivalent impedance, node voltage and node current of the phase-shifting transformer;

[0052] In this step, the phase-shifting transformer includes three-phase circuits A, B and C, and each phase circuit includes a parallel transformer (or parallel transformer) and a series transformer (or parallel transformer). The fault node information includes the fault node number and the short-circuit impedance value. The equivalent impedance circuit of the phase-shifting transformer is determined by the circuit structure and node number of the phase-shifting transformer, and the constraint relationship between the equivalent impedance, node voltage and node current is determined to obtain the electromagnetic constraint parameters.

[0053] Optionally, before obtaining the electromagnetic constraint parameters and fault node information of the phase-shifting transformer, it also includes: establishing an equivalent circuit model of the phase-shifting transformer based on the first equivalent impedance of the three-phase parallel transformer and the second equivalent impedance of the three-phase series transformer of the phase-shifting transformer; and determining the electromagnetic constraint parameters based on the equivalent circuit model.

[0054] In this optional embodiment, if Figure 2 The equivalent circuit model and node number diagram shown, U SA , U SB , U SC is the input voltage of the three phases A, B and C of the phase-shifting transformer; U LA , U LB , ULC is the output voltage of the three phases A, B and C of the phase-shifting transformer; I SA ,I SB ,I SC is the input current of the three phases A, B and C of the phase-shifting transformer; I LA ,I LB ,I LC is the output current of the three phases A, B and C of the phase-shifting transformer; U S1A , U S1B , U S1C is the midpoint voltage of the primary winding of the three-phase series transformer A, B and C; U A1 , U A2 , U B1 , U B2 , U C1 , U C2 is the voltage of the primary winding of the three-phase series transformer A, B and C; U SA2 , U SB2 , U SC2 is the voltage of the secondary winding of the three-phase series transformer A, B and C; I SA2 ,I SB2 ,I SC2 is the current of the secondary winding of the three-phase series transformer A, B and C; U E1A , U E1B , U E1C is the voltage of the primary winding of the three-phase parallel transformer A, B and C; U E2A , U E2B , U E2C is the voltage of the secondary winding of the three-phase parallel transformer A, B and C; U E2L(A) , U E2L(B) , U E2L(C) is the output voltage of the secondary side of the three-phase parallel transformer A, B and C; I E1A ,I E1B ,I E1C is the current of the primary winding of the three-phase parallel transformer A, B and C; I E2A ,I E2B ,I E2C is the current of the secondary winding of the three-phase parallel transformer A, B and C; Z S1A , Z S3A is the leakage impedance of the primary winding of the A-phase series transformer; Z S2A is the leakage impedance of the secondary winding of the A-phase series transformer; Z E1A is the leakage reactance of the primary winding of the A-phase parallel transformer; Z E2A N is the leakage reactance of the secondary winding of the A-phase parallel transformer; S1A 、N S2A N is the ratio of the total number of turns of the primary winding of the A-phase series transformer to the number of turns of the secondary winding;EA is the ratio of the number of turns of the primary winding of the A-phase parallel transformer to the total number of turns of the secondary winding; D A It is the ratio of the number of turns connected to the secondary winding of the A-phase parallel transformer to the total number of turns. It should be understood that it is similar to phase A, and phases B and C will not be repeated.

[0055] For example, taking phase A as an example, the calculation process of phases B and C is the same as that of phase A, which will not be repeated here. The first equivalent impedance is calculated according to the parameters of the parallel transformer of phase A in the phase-shifting transformer:

[0056]

[0057] Where Z E1A , Z E2A is the equivalent impedance of the primary and secondary sides of the A-phase parallel transformer, U N1E , U N2E is the rated voltage of the primary and secondary sides of the A-phase parallel transformer, S NE is the capacity of the parallel transformer, V SE % is the per unit value of short-circuit impedance.

[0058] The second equivalent impedance is calculated based on the A-phase series transformer parameters in the phase-shifting transformer:

[0059]

[0060] Where Z S1A , Z S1A , Z S2A is the equivalent impedance of the three windings of the A-phase series transformer, U N1S , U N2S is the rated voltage of the three windings of the A-phase series transformer, S NE is the capacity of the series transformer, V SS % is the per unit short-circuit impedance. Since the parameters of the second and third windings are the same, their equivalent reactances are equal.

[0061] Furthermore, based on the equivalent circuit model, the electromagnetic constraint parameters are determined: Taking the A-phase parallel transformer as an example, the calculation process of the B-phase and C-phase parallel transformers and the three-phase series transformer is similar to that of the A-phase, which will not be repeated here. According to the circuit structure and node numbering of the equivalent circuit model, the electromagnetic constraint parameters of the parallel transformer can be obtained:

[0062]

[0063]

[0064] Where Z E1A , Z E2A is the equivalent impedance of the primary and secondary sides of the A-phase parallel transformer; NEA is the transformation ratio of the parallel transformer; U 22 ′、U 33 ' is the primary side voltage and the secondary side voltage; I2 and I3 are the inflow currents of the primary side and the secondary side.

[0065] Step S102, determining a fixed admittance matrix of the phase-shifting transformer based on the electromagnetic constraint parameters, wherein the fixed admittance matrix includes node admittances of multiple nodes of the phase-shifting transformer, and the fixed admittance matrix is ​​a parameter matrix that uses node voltages to represent node injection currents;

[0066] In this step, the fixed admittance matrix is ​​the admittance matrix of the entire phase-shifting transformer, which can be obtained by merging the first admittance matrix of the three-phase parallel transformer and the second admittance matrix of the three-phase series transformer. Optionally, in one embodiment, the fixed admittance matrix of the phase-shifting transformer is determined based on the electromagnetic constraint parameters, including: determining the first admittance matrix of the three-phase parallel transformer in the phase-shifting transformer according to the electromagnetic constraint parameters; determining the second admittance matrix of the three-phase series transformer in the phase-shifting transformer according to the electromagnetic constraint parameters; merging and grounding the first admittance matrix and the second admittance matrix to obtain the fixed admittance matrix.

[0067] In this optional embodiment, the first admittance matrix of the three-phase parallel transformer and the second admittance matrix of the three-phase series transformer are obtained respectively through electromagnetic constraint parameters, and the first admittance matrix and the second admittance matrix are merged and grounded to obtain a fixed admittance matrix, so as to utilize the equivalent circuit principle corresponding to the electromagnetic constraint parameters to represent the relationship between the circuit impedance, voltage and current as a whole, and provide a theoretical basis for the subsequent determination of the short-circuit current.

[0068] Step S103, modifying the fixed admittance matrix according to the fault node information to obtain a target admittance matrix;

[0069] In this step, the fault position of the phase-shifting transformer is located according to the fault node number, and the admittance of the corresponding position in the fixed admittance matrix is ​​corrected to obtain the target admittance matrix with a short-circuit fault, so that the short-circuit current can be determined subsequently by combining the target admittance matrix with the equivalent circuit principle.

[0070] Step S104: determining the short-circuit current of the phase-shifting transformer based on the target admittance matrix.

[0071] In this embodiment, the node injection current of the phase-shifting transformer is obtained, and the node voltage can be obtained according to the electromagnetic constraint parameters. Then, the short-circuit current of the fault node can be obtained by using the node voltage and the target admittance matrix.

[0072] Optionally, in Figure 1On the basis of the shown embodiment, the first admittance matrix of the three-phase parallel transformer in the phase-shifting transformer is determined according to the electromagnetic constraint parameters, including: performing data replacement on the electromagnetic constraint parameters to generate three first indefinite admittance matrices of the three-phase parallel transformer; adding the three first indefinite admittance matrices to obtain the first admittance matrix.

[0073] In this optional embodiment, according to the electromagnetic constraint parameters of the parallel transformer, let Get the indefinite admittance matrix Y of phase A of the parallel transformer E1 :

[0074]

[0075] In the same way as phase A, the indefinite admittance matrix of phase B and phase C is calculated to obtain the indefinite admittance matrix Y of phase B and phase C. E2 , Y E3 , and add the three-phase indefinite admittance matrices to obtain the first admittance matrix Y of the three-phase parallel transformer E .

[0076] Optionally, in Figure 1 On the basis of the shown embodiment, the second admittance matrix of the three-phase series transformer in the phase-shifting transformer is determined according to the electromagnetic constraint parameters, including: determining the voltage-current relationship of the three-phase series transformer according to the electromagnetic constraint parameters and the circuit connection method of the phase-shifting transformer; performing data transformation on the voltage-current relationship to obtain three second indefinite admittance matrices of the three-phase series transformer; and adding the three second indefinite admittance matrices to obtain the second admittance matrix.

[0077] In this optional embodiment, according to the electromagnetic constraint parameters and circuit connection mode of the series transformer, the voltage-current relationship can be obtained:

[0078] U 2′ =U1-(I1Z S1A +U A1 );

[0079] U4=U2-U A1 -I2Z S3A ;

[0080] U 11 -U7=U SA2 -I7Z S2A ;

[0081] U A1 =N S1A U SA2 ;

[0082] UA2 =N S2A U SA2 ;

[0083] I7=I1N S1A -I2N S2A ;

[0084] U 2′ =U2;

[0085] Where Z S1A , Z S2A , Z S3A are the equivalent impedances of the three windings of the series transformer; N S1A 、N S2A are the turns ratios of windings 1 and 3 and windings 2 and 3 respectively; U A1 , U A2 are the voltages of the three windings; U1, U 2′ 、U2、U4、U7、U 11 is the port voltage value; I1, I2, I7 are the currents flowing through the three windings respectively.

[0086] Then the indefinite admittance matrix Y of the A-phase series transformer is S1 :

[0087]

[0088] in:

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097] M A2 =N S1A N S2A Z S2A ;

[0098]

[0099] In the same way as phase A, phases B and C are processed to obtain the indefinite admittance matrix Y of phases B and C. S2 , Y S3 , and add the three-phase indefinite admittance matrices to obtain the second admittance matrix Y of the three-phase parallel transformer S .

[0100] Optionally, in Figure 1 On the basis of the illustrated embodiment, the first admittance matrix and the second admittance matrix are merged and grounded to obtain the fixed admittance matrix, including: according to the connected nodes of the phase-shifting transformer, the first admittance matrix and the second admittance matrix are merged to obtain a third admittance matrix; according to the circuit connection method of the phase-shifting transformer, the grounded nodes in the third admittance matrix are grounded to obtain the fixed admittance matrix.

[0101] In this optional embodiment, the first admittance matrix Y E and the second admittance matrix Y S The corresponding items are added, and the connected nodes are merged according to the node merging method to obtain the final admittance matrix Y PST0 Taking the merging of the two nodes corresponding to node number 1 and node number as an example, the third admittance matrix is:

[0102]

[0103] Further, the ground nodes in the third admittance matrix are processed according to the circuit connection mode. PST0 Delete the rows and columns of the grounding nodes in the phase-shifting transformer to obtain the fixed admittance matrix Y PST , taking node number 13 as the grounding node as an example, the admittance matrix is:

[0104]

[0105] In one embodiment, Figure 1 Based on the embodiment shown, the above step S103 includes:

[0106] According to the short-circuit impedance value, the node admittance corresponding to the node number in the fixed admittance matrix is ​​corrected to obtain the target admittance matrix.

[0107] In this optional embodiment, the admittance matrix is ​​corrected according to the fault location. Taking the two-phase grounding fault of node number 1 and node number 2 as an example, the corrected target admittance matrix is ​​as follows:

[0108]

[0109] Let the admittance matrix Y PSTElements in (node ​​admittance) Corrected to element Corrected to The other elements in the matrix remain unchanged, Z fault is the short-circuit impedance value, It represents the target admittance matrix, that is, the admittance matrix after the fault. The processing of other fault types is similar to the above process and will not be repeated here.

[0110] In one embodiment, Figure 1 Based on the embodiment shown, the above step S104 includes:

[0111] Determining a target node voltage of the phase-shifting transformer based on the target admittance matrix and the node injection current;

[0112] The short-circuit current of the phase-shifting transformer is determined according to the target node voltage and the electromagnetic constraint parameter.

[0113] In this optional embodiment, the node voltage is calculated based on the target admittance matrix, and then the current of each branch is calculated based on the electromagnetic constraint parameters. The process is as follows:

[0114]

[0115] Wherein U is the node voltage, I is the node injection current, and the injection current value is the excitation value of the current source connected to the node; after obtaining the node voltage, the electromagnetic constraint parameters of the above step S101 are used to obtain the branch currents I2 and I3, and the other branch currents are similar, and finally the short-circuit current is obtained.

[0116] In order to perform the short-circuit current determination method corresponding to the above method embodiment, the corresponding functions and technical effects are achieved. Figure 6 , Figure 6 The structure block diagram of a short-circuit current determination device provided by an embodiment of the present application is shown. For the convenience of explanation, only the parts related to the present embodiment are shown. The short-circuit current determination device provided by the embodiment of the present application includes:

[0117] An acquisition module 601 is used to acquire electromagnetic constraint parameters and fault node information of a phase-shifting transformer, wherein the electromagnetic constraint parameters are constraint parameters between equivalent impedance, node voltage and node current of the phase-shifting transformer;

[0118] A first determination module 602 is used to determine a fixed admittance matrix of the phase-shifting transformer based on the electromagnetic constraint parameters, wherein the fixed admittance matrix includes node admittances of multiple nodes of the phase-shifting transformer, and the fixed admittance matrix is ​​a parameter matrix that uses node voltages to represent node injection currents;

[0119] A correction module 603 is used to correct the fixed admittance matrix according to the fault node information to obtain a target admittance matrix;

[0120] The second determination module 604 is configured to determine the short-circuit current of the phase-shifting transformer based on the target admittance matrix.

[0121] In one embodiment, the first determining module 602 includes:

[0122] A first determining unit, configured to determine a first admittance matrix of a three-phase parallel transformer in the phase-shifting transformer according to the electromagnetic constraint parameter;

[0123] A second determination unit, configured to determine a second admittance matrix of a three-phase series transformer in the phase-shifting transformer according to the electromagnetic constraint parameter;

[0124] A processing unit is used to combine and ground the first admittance matrix and the second admittance matrix to obtain the fixed admittance matrix.

[0125] Optionally, the first determining unit includes:

[0126] A replacement subunit, used for performing data replacement on the electromagnetic constraint parameters to generate three first indefinite admittance matrices of the three-phase parallel transformer;

[0127] The first adding subunit is used to add the three first indefinite admittance matrices to obtain the first admittance matrix.

[0128] Optionally, the second determining unit includes:

[0129] A determination subunit, configured to determine a voltage-current relationship of the three-phase series transformer according to the electromagnetic constraint parameters and a circuit connection mode of the phase-shifting transformer;

[0130] A transformation subunit performs data transformation on the voltage-current relationship to obtain three second indefinite admittance matrices of the three-phase series transformer;

[0131] The second adding subunit is used to add the three second indefinite admittance matrices to obtain the second admittance matrix.

[0132] Optionally, the processing unit includes:

[0133] a merging subunit, configured to merge the first admittance matrix and the second admittance matrix according to the connected nodes of the phase-shifting transformer to obtain a third admittance matrix;

[0134] The processing subunit is used to perform grounding processing on the grounding nodes in the third admittance matrix according to the circuit connection mode of the phase-shifting transformer to obtain the fixed admittance matrix.

[0135] In one embodiment, the fault node information includes a fault node number and a short-circuit impedance value, and the correction module 603 includes:

[0136] A correction unit is used to correct the node admittance corresponding to the node number in the fixed admittance matrix according to the short-circuit impedance value to obtain the target admittance matrix.

[0137] In one embodiment, the second determining module 604 includes:

[0138] A third determining unit, configured to determine a target node voltage of the phase-shifting transformer based on the target admittance matrix and the node injection current;

[0139] The fourth determining unit is used to determine the short-circuit current of the phase-shifting transformer according to the target node voltage and the electromagnetic constraint parameter.

[0140] In one embodiment, the determining device further includes:

[0141] An establishing module, used to establish an equivalent circuit model of the phase-shifting transformer according to a first equivalent impedance of a three-phase parallel transformer and a second equivalent impedance of a three-phase series transformer of the phase-shifting transformer;

[0142] The third determination module is used to determine the electromagnetic constraint parameters based on the equivalent circuit model.

[0143] The above-mentioned short-circuit current determination device can implement the short-circuit current determination method of the above-mentioned method embodiment. The options in the above-mentioned method embodiment are also applicable to this embodiment and will not be described in detail here. The rest of the contents of the embodiment of this application can refer to the contents of the above-mentioned method embodiment, and will not be repeated in this embodiment.

[0144] Figure 7 This is a schematic diagram of the structure of a computer device provided in one embodiment of the present application. Figure 7 As shown, the computer device 7 of this embodiment includes: at least one processor 70 ( Figure 7 Only one is shown in the figure) a processor, a memory 71, and a computer program 72 stored in the memory 71 and executable on the at least one processor 70, and when the processor 70 executes the computer program 72, the steps in any of the above method embodiments are implemented.

[0145] The computer device 7 may be a computing device such as a smart phone, a tablet computer, a desktop computer, a cloud server, etc. The computer device may include but is not limited to a processor 70 and a memory 71. Those skilled in the art will appreciate that Figure 7 It is only an example of the computer device 7 and does not constitute a limitation on the computer device 7. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, it may also include input and output devices, network access devices, etc.

[0146] The processor 70 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0147] In some embodiments, the memory 71 may be an internal storage unit of the computer device 7, such as a hard disk or memory of the computer device 7. In other embodiments, the memory 71 may also be an external storage device of the computer device 7, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the computer device 7. Further, the memory 71 may also include both an internal storage unit and an external storage device of the computer device 7. The memory 71 is used to store an operating system, an application program, a boot loader (BootLoader), data, and other programs, such as the program code of the computer program. The memory 71 may also be used to temporarily store data that has been output or is to be output.

[0148] In addition, an embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps in any of the above method embodiments are implemented.

[0149] An embodiment of the present application provides a computer program product. When the computer program product is run on a terminal device, the terminal device implements the steps in the above-mentioned method embodiments when executing the computer program product.

[0150] In several embodiments provided in the present application, it is understood that each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved.

[0151] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can essentially be embodied in the form of a software product, or in other words, the part that contributes to the prior art or the part of the technical solution. The computer software product is stored in a storage medium, including several instructions for enabling a terminal device to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0152] The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present application in detail. It should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the scope of protection of the present application. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for determining the short-circuit current of a phase-shifting transformer, characterized in that: include: Acquire electromagnetic constraint parameters and fault node information of the phase-shifting transformer, wherein the electromagnetic constraint parameters are constraint parameters between equivalent impedance, node voltage and node current of the phase-shifting transformer; Based on the electromagnetic constraint parameters, determining a fixed admittance matrix of the phase-shifting transformer, wherein the fixed admittance matrix includes node admittances of multiple nodes of the phase-shifting transformer, and the fixed admittance matrix is ​​a parameter matrix that uses node voltages to represent node injection currents; According to the fault node information, the fixed admittance matrix is ​​corrected to obtain a target admittance matrix; Based on the target admittance matrix, a short-circuit current of the phase-shifting transformer is determined.

2. The short-circuit current determination method according to claim 1, characterized in that: The step of determining the fixed admittance matrix of the phase-shifting transformer based on the electromagnetic constraint parameters comprises: Determining a first admittance matrix of a three-phase parallel transformer in the phase-shifting transformer according to the electromagnetic constraint parameters; Determining a second admittance matrix of a three-phase series transformer in the phase-shifting transformer according to the electromagnetic constraint parameters; The first admittance matrix and the second admittance matrix are combined and grounded to obtain the fixed admittance matrix.

3. The short-circuit current determination method according to claim 2, characterized in that: The step of determining a first admittance matrix of a three-phase parallel transformer in the phase-shifting transformer according to the electromagnetic constraint parameters comprises: Performing data replacement on the electromagnetic constraint parameters to generate three first indefinite admittance matrices of the three-phase parallel transformer; The three first indefinite admittance matrices are added to obtain the first admittance matrix.

4. The short-circuit current determination method according to claim 2, characterized in that: The step of determining a second admittance matrix of a three-phase series transformer in the phase-shifting transformer according to the electromagnetic constraint parameters comprises: Determining the voltage-current relationship of the three-phase series transformer according to the electromagnetic constraint parameters and the circuit connection mode of the phase-shifting transformer; Performing data transformation on the voltage-current relationship to obtain three second indefinite admittance matrices of the three-phase series transformer; The three second indefinite admittance matrices are added to obtain the second admittance matrix.

5. The short-circuit current determination method according to claim 2, characterized in that: The step of combining and grounding the first admittance matrix and the second admittance matrix to obtain the fixed admittance matrix includes: According to the connected nodes of the phase-shifting transformer, the first admittance matrix and the second admittance matrix are combined to obtain a third admittance matrix; According to the circuit connection mode of the phase-shifting transformer, the grounding nodes in the third admittance matrix are grounded to obtain the fixed admittance matrix.

6. The short-circuit current determination method according to any one of claims 1 to 5, characterized in that: The fault node information includes a fault node number and a short-circuit impedance value. The fixed admittance matrix is ​​corrected according to the fault node information to obtain a target admittance matrix, including: According to the short-circuit impedance value, the node admittance corresponding to the node number in the fixed admittance matrix is ​​corrected to obtain the target admittance matrix.

7. The short-circuit current determination method according to any one of claims 1 to 5, characterized in that: The determining the short-circuit current of the phase-shifting transformer based on the target admittance matrix includes: Determining a target node voltage of the phase-shifting transformer based on the target admittance matrix and the node injection current; The short-circuit current of the phase-shifting transformer is determined according to the target node voltage and the electromagnetic constraint parameter.

8. The short-circuit current determination method according to any one of claims 1 to 5, characterized in that: Before obtaining the electromagnetic constraint parameters and fault node information of the phase-shifting transformer, the method further includes: Establishing an equivalent circuit model of the phase-shifting transformer according to a first equivalent impedance of a three-phase parallel transformer and a second equivalent impedance of a three-phase series transformer of the phase-shifting transformer; Based on the equivalent circuit model, the electromagnetic constraint parameters are determined.

9. A short-circuit current determination device for a phase-shifting transformer, characterized in that: include: An acquisition module, used to acquire electromagnetic constraint parameters and fault node information of a phase-shifting transformer, wherein the electromagnetic constraint parameters are constraint parameters between equivalent impedance, node voltage and node current of the phase-shifting transformer; A first determination module is used to determine a fixed admittance matrix of the phase-shifting transformer based on the electromagnetic constraint parameters, wherein the fixed admittance matrix includes node admittances of multiple nodes of the phase-shifting transformer, and the fixed admittance matrix is ​​a parameter matrix that uses node voltages to represent node injection currents; A correction module, used for correcting the fixed admittance matrix according to the fault node information to obtain a target admittance matrix; The second determination module is used to determine the short-circuit current of the phase-shifting transformer based on the target admittance matrix.

10. A computer device, characterized in that: The method comprises a processor and a memory, wherein the memory is used to store a computer program, and when the computer program is executed by the processor, the steps of the method for determining the short-circuit current of the phase-shifting transformer as claimed in any one of claims 1 to 8 are implemented.

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