Incoming end impedance calculation method of saturable reactor broadband equivalent circuit model

Abstract

The invention discloses an incoming end impedance calculation method of a saturable reactor broadband equivalent circuit model, and relates to the technical field of impedance analysis of a power system. In the method, a broadband equivalent circuit model of a saturable reactor in the converter valve is equivalent to a passive two-port network connected with a load; carrying out decoupling equivalent operation on inductors containing mutual inductance in the passive two-port network; taking each element except a load in the decoupled saturable reactor broadband equivalent circuit model as a two-port, and determining a transmission parameter matrix of each two-port; obtaining a transmission parameter matrix of the passive two-port network according to a two-port cascade principle and the transmission parameter matrix of each two-port; and determining the input end impedance of the saturable reactor broadband equivalent circuit model according to the relationship between the transmission parameter matrix of the passive two-port network and the input end voltage, the input end current, the output end voltage and the output end current. According to the method, the calculation efficiency of the input end impedance of the saturable reactor broadband equivalent circuit model can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of power system impedance analysis, and in particular to a method for calculating input impedance of a broadband equivalent circuit model of a saturated reactor. Background Art

[0002] As one of the most critical devices in the HVDC transmission system, the converter valve is mainly responsible for the functions of rectification and inversion. The converter valve is usually composed of saturated reactors, thyristors, damping capacitors and other components. In the converter valve, the saturated reactor is connected in series with the thyristor. Its function is to limit the misconduction or damage of the thyristor caused by drastic changes in current and voltage through its damping effect. Since the thyristor of the converter valve generates electromagnetic interference when it is turned on and off, the electromagnetic interference will be transmitted to each component.

[0003] Therefore, in order to predict the conducted electromagnetic interference and understand the loss of the saturated reactor, it is often necessary to establish a broadband equivalent circuit model of each component in the converter valve and analyze its impedance change through the equivalent circuit model. The input impedance of the equivalent circuit model is often calculated by connecting the components of the equivalent circuit model in series and parallel to obtain the relationship between the input voltage and the input current to calculate the input impedance of the broadband equivalent circuit model of the saturated reactor.

[0004] However, for different converter valves, the measured scattering parameters will vary greatly, which will cause the self-inductance in the wide-band equivalent circuit model of the saturated reactor to change. Therefore, when calculating the input impedance of the wide-band equivalent circuit model of the saturated reactor with different self-inductances, it is necessary to repeatedly simplify the series and parallel connection of the model elements, which leads to the problem of low calculation efficiency in the method of calculating the input impedance of the wide-band equivalent circuit model of the saturated reactor. Summary of the invention

[0005] Based on this, it is necessary to provide a method for calculating the input impedance of a wide-band equivalent circuit model of a saturated reactor in response to the above technical problems. This method can improve the calculation efficiency of the input impedance of the wide-band equivalent circuit model of a saturated reactor.

[0006] The present invention adopts the following technical solutions:

[0007] The present invention provides a method for calculating the input impedance of a wide-band equivalent circuit model of a saturated reactor, comprising:

[0008] The broadband equivalent circuit model of the saturable reactor in the converter valve is equivalent to a passive two-port network connected to a load;

[0009] Perform decoupling equivalent operation on the inductor containing mutual inductance in the passive two-port network to obtain a broadband equivalent circuit model of the decoupled saturated reactor;

[0010] Each element except the load in the broadband equivalent circuit model of the decoupled saturated reactor is regarded as a two-port, and the transmission parameter matrix of each two-port is determined;

[0011] According to the two-port cascade principle and the transmission parameter matrix of each two-port, the transmission parameter matrix of the passive two-port network is obtained;

[0012] According to the relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current, the input impedance of the broadband equivalent circuit model of the saturated reactor is determined.

[0013] Optionally, the decoupling equivalent operation is a process of converting a circuit containing mutual inductance into an equivalent circuit without mutual inductance; for a T-connected circuit containing mutual inductance, the equivalent circuit after decoupling is a circuit composed of three inductors without mutual inductance.

[0014] Optionally, the two ports in the broadband equivalent circuit model of the decoupled saturated reactor include a resistor R 1 The corresponding two-port NR 1 、Inductance L 1 -M, L 2 -M corresponding to the two-port NL 1 -M and NL 2 -M, capacitor C 1 A two-port NC is formed in series with the mutual inductance M. 1 _M, resistance R 2 , R 3 and R 4 The corresponding two-port NR 2 NR 3 and NR 4 , self-sensing L 3 , L 4 The corresponding two-port NL 3 and NL 4 , resistor R 5 With self-sensing 5 The corresponding two-port NR in parallel 5 ||L 5 , capacitor C 2 , C 3 Corresponding two-port NC 2 and NC 3 ;

[0015] The transmission parameter matrix of each two-port is:

[0016]

[0017]

[0018] in, Indicates two-port NR 1 The transmission parameter matrix of Indicates two-port NL 1 -M is the transmission parameter matrix, ω represents the frequency of the input voltage in the broadband equivalent circuit model of the decoupled saturated reactor; Indicates two-port NC 1 _M's transmission parameter matrix; Indicates two-port NL 2 -M transmission parameter matrix; Indicates two-port NR 2 ; Indicates two-port NL 3 The transmission parameter matrix of Indicates two-port NR 3 The transmission parameter matrix of Indicates two-port NL 4 The transmission parameter matrix of Indicates two-port NR 4 The transmission parameter matrix of Indicates two-port NC 2 The transmission parameter matrix of Indicates two-port NR 5 ||L 5 The transmission parameter matrix of Indicates two-port NC 3 The transmission parameter matrix.

[0019] Optionally, according to the two-port cascade principle and the transmission parameter matrix of each two-port, a transmission parameter matrix of the passive two-port network is obtained, including:

[0020] According to the two-port cascade principle, the transmission parameter matrices of the two ports are multiplied according to the cascade order of the two ports in the broadband equivalent circuit model of the decoupled saturated reactor to obtain the transmission parameter matrix of the passive two-port network.

[0021] Optionally, according to the relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current, the input impedance of the broadband equivalent circuit model of the saturated reactor is determined, including:

[0022] According to the relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current, and the relationship between the output voltage, input voltage and load resistance, the calculation formula of the input impedance of the broadband equivalent circuit model of the saturated reactor is determined;

[0023] Substituting each element of the transmission parameter matrix of the passive two-port network into the calculation formula, the input impedance of the broadband equivalent circuit model of the saturated reactor is obtained.

[0024] Optionally, the transmission parameter matrix A of the passive two-port network is:

[0025]

[0026] Among them, A 11 , A 12 , A 21 , A 22 is the element of the transmission parameter matrix A of the passive two-port network, that is, the transmission parameter of the passive two-port network;

[0027] The relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current is:

[0028] U 1 =A 11 U 2 +A 12 (-I 2 );

[0029] I 1 =A 12 U 2 +A 22 (-I 2 );

[0030] Among them, U 1 Indicates the input voltage, I 1 Indicates the input current, I 2 Indicates the output current, U 2 Indicates the output voltage, U 2 =-R 6 I 2 , R 6 is the load resistance;

[0031] The calculation formula of the input impedance of the broadband equivalent circuit model of the saturated reactor is:

[0032]

[0033] Optionally, the method further comprises:

[0034] When self-inductance is added to the broadband equivalent circuit model of the saturated reactor, a transmission parameter matrix of two ports corresponding to the self-inductance is obtained;

[0035] According to the position of the added self-inductance in the broadband equivalent circuit model of the saturated reactor, according to the cascade position of the two ports corresponding to the self-inductance;

[0036] Determine the transmission parameter matrix of the passive two-port network according to the cascade position of the two ports corresponding to the self-inductance;

[0037] Substitute each element of the transmission parameter matrix of the passive two-port network into the calculation formula of the input impedance of the broadband equivalent circuit model of the saturated reactor to determine the input impedance of the broadband equivalent circuit model of the saturated reactor.

[0038] The present invention provides an input impedance calculation device for a wide-band equivalent circuit model of a saturated reactor, comprising:

[0039] An equivalent module is used to convert a broadband equivalent circuit model of a saturated reactor in a converter valve into a passive two-port network connected to a load;

[0040] A decoupling module is used to perform a decoupling equivalent operation on the inductor containing mutual inductance in the passive two-port network to obtain a broadband equivalent circuit model of the saturated reactor after decoupling;

[0041] A first determination module is used to treat each element except the load in the broadband equivalent circuit model of the decoupled saturated reactor as a two-port, and determine the transmission parameter matrix of each two-port;

[0042] A second determination module is used to obtain a transmission parameter matrix of a passive two-port network according to a two-port cascade principle and a transmission parameter matrix of each two-port;

[0043] The third determination module is used to determine the input impedance of the broadband equivalent circuit model of the saturated reactor according to the relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current.

[0044] The present invention provides a computer-readable storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the input impedance calculation method of the above-mentioned saturated reactor wide-band equivalent circuit model is implemented.

[0045] The present invention provides a computer device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the input impedance calculation method of the above-mentioned saturated reactor wide-band equivalent circuit model when executing the program.

[0046] At least one of the above technical solutions adopted by the present invention can achieve the following beneficial effects:

[0047] In the present invention, the broadband equivalent circuit model of the saturated reactor in the converter valve is equivalent to a passive two-port network including a load, and each component except the load is regarded as a two-port, and the transmission parameter matrix of the two-port corresponding to each component is calculated respectively. Then, according to the principle of two-port cascade, the transmission parameter matrix of the passive two-port network corresponding to the broadband equivalent circuit model of the saturated reactor is obtained. Then, according to the relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current, the input impedance of the broadband equivalent circuit model of the saturated reactor in the converter valve is directly calculated. In this way, the conventional method of gradually deriving the relationship between the input voltage and input current of the model by using the series and parallel connection of components in the equivalent circuit model and then calculating the input impedance is avoided, thereby improving the efficiency of calculating the input impedance of the broadband equivalent circuit model of the saturated reactor in the converter valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0049] Figure 1 A schematic diagram of a broadband equivalent circuit model of a saturated reactor in a converter valve provided by the present invention;

[0050] Figure 2 A schematic flow chart of a method for calculating input impedance of a wide-band equivalent circuit model of a saturated reactor provided by the present invention;

[0051] Figure 3 A schematic diagram of a passive two-port network corresponding to a broadband equivalent circuit model of a saturated reactor in a converter valve provided by the present invention;

[0052] Figure 4 A schematic diagram of a broadband equivalent circuit model of a saturated reactor in a decoupled converter valve provided by the present invention;

[0053] Figure 5 A schematic diagram of a two-port network of cascaded components in a broadband equivalent circuit model of a saturated reactor in a decoupled converter valve provided by the present invention;

[0054] Figure 6 A schematic diagram of a two-port network of cascaded components in a broadband equivalent circuit model of a saturated reactor in a decoupled converter valve provided by the present invention;

[0055] Figure 7 A schematic diagram of an input impedance calculation device for a wide-band equivalent circuit model of a saturated reactor provided by the present invention;

[0056] Figure 8A schematic diagram of a computer device for realizing a method for calculating input impedance of a wide-band equivalent circuit model of a saturated reactor provided by the present invention. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0058] At present, the broadband equivalent circuit model of the saturated reactor in the converter valve can be measured by network analyzers and other equipment to measure the scattering parameters of the saturated reactor, and then the broadband impedance characteristics of the driving point of the saturated reactor are calculated by the scattering parameters. Then, the impedance characteristics are converted and approximated using rational expressions to obtain their rational approximation expressions. Then, according to the rational expressions, network synthesis is performed on them to establish the broadband equivalent circuit model of the saturated reactor. Typical equivalent circuit models are as follows: Figure 1 As shown, the model includes the resistor R 1 ~R 6 , inductor L with coupled mutual inductance M 1 and L 2 , self-sensing L 3 , L 4 , L 5 , capacitor C 1 , C 2 , C 3 After obtaining the broadband equivalent circuit model of the saturated reactor, the input impedance of the model is currently calculated by connecting the model components obtained by network synthesis in series and in parallel to simplify them, and obtaining the relationship between the input voltage and the input current to calculate the input impedance of the broadband equivalent circuit model of the saturated reactor.

[0059] However, for different converter valves, the measured scattering parameters will vary greatly, which will cause the self-inductance in the broadband equivalent circuit model of the saturated reactor obtained by network synthesis to change. In order to avoid the repeated use of the series-parallel relationship of component parameters for simplification due to the change in the self-inductance in the equivalent circuit, the present application proposes a new input impedance calculation method for the broadband equivalent circuit model of the saturated reactor. By using this method, for equivalent circuit models with different numbers of self-inductances, the complicated series-parallel simplification process of component parameters can be avoided, the input impedance calculation of the broadband equivalent circuit model of the saturated reactor is simplified, and the input impedance of the broadband equivalent circuit model of the saturated reactor with different numbers of self-inductances can be quickly calculated.

[0060] The technical solutions provided by various embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0061] Figure 2 The present invention is a flow chart of a method for calculating the input impedance of a wide-band equivalent circuit model of a saturated reactor, which specifically includes the following steps:

[0062] S201, equating a broadband equivalent circuit model of a saturable reactor in a converter valve to a passive two-port network connected to a load.

[0063] Typically, see Figure 1 The broadband equivalent circuit model of the saturated reactor in the converter valve is a one-port network, and the one-port network is regarded as a two-port network connected to the load; specifically, the broadband equivalent circuit model of the saturated reactor in the converter valve is equivalent to a passive two-port network connected to the load, including: Figure 1 The resistance R 6 As the load of the saturated reactor, a passive two-port network connected to the load is obtained, such as Figure 3 shown.

[0064] Input voltage U of saturated reactor 1 and input current I 1 Defined as a variable of one port (port 1), the output voltage U 2 and output current I 2 A variable defined as another port (port 2).

[0065] S202, performing a decoupling equivalent operation on the inductor containing mutual inductance in the passive two-port network to obtain a broadband equivalent circuit model of a decoupled saturated reactor.

[0066] Optionally, the decoupling equivalent operation is a process of converting a circuit containing mutual inductance into an equivalent circuit without mutual inductance; for a T-connected circuit containing mutual inductance, the equivalent circuit after decoupling is a circuit composed of three inductors without mutual inductance.

[0067] Will Figure 3 The inductor L contains the mutual inductance 1 and L 2 Decoupling, we get Figure 4 The broadband equivalent circuit model of the saturated reactor in the decoupled converter valve is shown in FIG. 1 and L 2 Decoupling, we get three inductors without mutual inductance. The three inductors obtained by decoupling are L 1 -M, L 2 -M, and M.

[0068] S203, each element except the load in the broadband equivalent circuit model of the decoupled saturated reactor is regarded as a two-port, and a transmission parameter matrix of each two-port is determined.

[0069] Each element except the load in the broadband equivalent circuit model of the decoupled saturated reactor is regarded as a two-port, such as Figure 5 As shown in the figure, the two ports in the broadband equivalent circuit model of the decoupled saturated reactor include a resistor R 1 The corresponding two-port NR 1 、Inductance L 1 -M, L 2 -M corresponding to the two-port NL 1 -M and NL 2 -M, capacitor C 1 A two-port NC is formed in series with the mutual inductance M. 1 _M, resistance R 2 , R 3 and R 4 The corresponding two-port NR 2 NR 3 and NR 4 , self-sensing L 3 , L 4 The corresponding two-port NL 3 and NL 4 , resistor R 5 With self-sensing 5 The corresponding two-port NR in parallel 5 ||L 5 , capacitor C 2 , C 3 Corresponding two-port NC 2 and NC 3 .

[0070] According to the definition of the two-port network transmission parameters and the relationship between the voltage and current of each two-port, the transmission parameter matrix of each two-port can be obtained; the transmission parameter matrix of each two-port is:

[0071]

[0072] in, Indicates two-port NR 1 The transmission parameter matrix of Indicates two-port NL 1 -M is the transmission parameter matrix, ω represents the frequency of the input voltage in the broadband equivalent circuit model of the decoupled saturated reactor; Indicates two-port NC 1 _M's transmission parameter matrix; Indicates two-port NL 2-M transmission parameter matrix; Indicates two-port NR 2 ; Indicates two-port NL 3 The transmission parameter matrix of Indicates two-port NR 3 The transmission parameter matrix of Indicates two-port NL 4 The transmission parameter matrix of Indicates two-port NR 4 The transmission parameter matrix of Indicates two-port NC 2 The transmission parameter matrix of Indicates two-port NR 5 ||L 5 The transmission parameter matrix of Indicates two-port NC 3 The transmission parameter matrix.

[0073] S204, obtaining a transmission parameter matrix of the passive two-port network according to the two-port cascade principle and the transmission parameter matrix of each two-port.

[0074] Specifically, according to the two-port cascade principle and the transmission parameter matrix of each two-port, the transmission parameter matrix of the passive two-port network is obtained, including: according to the two-port cascade principle, according to the cascade order of each two-port in the wide-band equivalent circuit model of the saturated inductor after decoupling, the transmission parameter matrix of each two-port is multiplied to obtain the transmission parameter matrix of the passive two-port network.

[0075] As shown in formula (1), formula (1) is the relationship between the transmission parameter matrix of each two-port and the transmission parameter matrix of the passive two-port network.

[0076]

[0077] Substitute the specific values ​​of the parameters of each component into formula (1), and calculate the value of the transmission parameter matrix A corresponding to the passive two-port network according to the multiplication of multiple second-order matrices in formula (1).

[0078] S205, determining the input impedance of the broadband equivalent circuit model of the saturated reactor according to the relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current.

[0079] Optionally, the input impedance of the broadband equivalent circuit model of the saturated reactor is determined according to the relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current, including: determining the calculation formula of the input impedance of the broadband equivalent circuit model of the saturated reactor according to the relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current, and the relationship between the output voltage, input voltage and load resistance; substituting each element of the transmission parameter matrix of the passive two-port network into the calculation formula to obtain the input impedance of the broadband equivalent circuit model of the saturated reactor.

[0080] Specifically, the transmission parameter matrix A of the passive two-port network is:

[0081]

[0082] Among them, A 11 , A 12 , A 21 , A 22 is the element of the transmission parameter matrix A of the passive two-port network, that is, the transmission parameter of the passive two-port network.

[0083] The relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current is:

[0084] U 1 =A 11 U 2 +A 12 (-I 2 ) (3)

[0085] I 1 =A 12 U 2 +A 22 (-I 2 ) (4)

[0086] Among them, U 1 Indicates the input voltage, I 1 Indicates the input current, I 2 Indicates the output current, U 2 Indicates the output voltage, U 2 =-R 6 I 2 , R 6 is the load resistance.

[0087] Formula (3) and formula (4) can be uniformly expressed in matrix form as follows:

[0088]

[0089] According to the calculation formula of the input impedance of the passive two-port network and combined with formulas (2)-(4), the calculation formula of the input impedance of the broadband equivalent circuit model of the saturated reactor is obtained. The calculation formula of the input impedance of the broadband equivalent circuit model of the saturated reactor is:

[0090]

[0091] The transmission parameter A calculated by formula (1) 11 , A 12 , A 21 , A 22 Substituting into formula (6) we can obtain the input impedance of the broadband equivalent circuit model of the saturated reactor.

[0092] The present invention regards the components in the model as mutually independent two-port networks, calculates the transmission parameter matrix of each two-port network, and then directly multiplies the transmission parameter matrices of all two-port networks through the cascade principle to calculate the transmission parameter matrix of the entire two-port network. Finally, only the load voltage, current and U at the end of this two-port network are used. 2 ,I 2 The input impedance of the entire model can be quickly calculated by the relationship between them.

[0093] In an exemplary embodiment, the embodiment includes: when self-inductance is added to the broadband equivalent circuit model of the saturated reactor, a transmission parameter matrix of the two ports corresponding to the self-inductance is obtained; according to the position of the added self-inductance in the broadband equivalent circuit model of the saturated reactor, according to the cascade position of the two ports corresponding to the self-inductance; according to the cascade position of the two ports corresponding to the self-inductance, a transmission parameter matrix of the passive two-port network is determined; and each element of the transmission parameter matrix of the passive two-port network is substituted into the calculation formula of the input impedance of the broadband equivalent circuit model of the saturated reactor to determine the input impedance of the broadband equivalent circuit model of the saturated reactor.

[0094] For example, when the number of self-inductors in the model changes, such as adding a self-inductor, Figure 6 As shown, Figure 5 Added L 5 , due to L 5 The structure is the same as other self-inductors, so directly according to the writing method of the two-port network transmission parameter matrix corresponding to the previous self-inductor, it is directly obtained as:

[0095]

[0096] At this time, there is no need to derive the formula again, just increase L 5 The corresponding two-port network transmission parameter matrix A NL5 , according to L 5At the location, simply add formula (7) to formula (1) to obtain the model to reduce L 4 After that, the transmission parameter matrix of the entire two-port network is:

[0097]

[0098] Substituting the elements of formula (8) into formula (6) can obtain the increased input impedance of the model.

[0099] Similarly, if the number of self-inductances in the broadband equivalent circuit model of the saturated reactor in the converter valve is reduced by one, such as reducing L 4 , at this time, we only need to replace A in formula (1) NL4 Just delete it and the remaining calculation steps remain unchanged.

[0100] It should be noted that the broadband equivalent circuit model of the saturated reactor in the present invention is a broadband equivalent circuit model of the saturated reactor in a converter valve in a ±500kV converter station, which is obtained after scattering parameter measurement, calculation of the broadband impedance characteristics of the driving point of the saturated reactor, rational approximation and network synthesis. The present invention only uses this model to illustrate the method provided by the present invention, that is, a broadband equivalent circuit model of a saturated reactor obtained by network synthesis is regarded as a passive two-port network connected to a load. Then, the inductor containing mutual inductance is subjected to a decoupling equivalent operation. Then, each element in the model is regarded as a two-port, and the transmission parameter matrix of each two-port containing only one element is calculated respectively. Then, using the two-port cascade principle, the two-port transmission parameter matrix of each element is multiplied to calculate the total transmission parameter matrix of the entire two-port network. Finally, by using the relationship between the input voltage, input current and transmission parameter matrix, and the relationship between the load terminal voltage and current, the input impedance of the broadband equivalent circuit model of the saturated reactor in the converter valve can be calculated. When the self-inductance element in the broadband equivalent circuit model of the saturated reactor in the converter valve increases or decreases, it is only necessary to multiply or delete the transmission parameter matrix of the two ports corresponding to the self-inductance element in the process of calculating the transmission parameter matrix of the two ports, and there is no need to use the series-parallel relationship of each element to simplify the relationship between the input voltage and the input current, so that when the broadband equivalent circuit model of the saturated reactor in the converter valve contains different numbers of self-inductance elements, the efficiency of calculating the input impedance of the model is higher. However, in practical applications, the structure of the broadband equivalent circuit model of the saturated reactor is not limited.

[0101] Furthermore, the input impedance at each frequency can be calculated by the calculation method of the present invention. Thus, the input impedance characteristics within the entire frequency range can be calculated, and a curve of the input impedance changing with frequency can be obtained.

[0102] The present invention proposes a method for calculating the input impedance of a broadband equivalent circuit model of a saturated reactor in a converter valve containing different numbers of self-inductance elements in a simple and efficient manner. When the parameters of the self-inductance elements in the model increase or decrease, it is only necessary to multiply or delete the two-port network transmission parameter matrix corresponding to the self-inductance element in the multiplied two-port transmission parameter matrix. The present invention avoids the need to reuse the series-parallel relationship of the elements for simplified derivation when the self-inductance elements in the model increase or decrease, and greatly improves the calculation efficiency of the input impedance of the broadband equivalent circuit model of the saturated reactor in the converter valve when the self-inductance elements in the model are different.

[0103] The method provided by the present invention can be executed by a server, which can be a server set up on a business platform, or a device such as a desktop computer, a notebook computer, etc. that can execute the solution of the present invention.

[0104] When the input impedance calculation method of the broadband equivalent circuit model of the saturated reactor provided by the present invention is applied, it is not necessary to calculate the input impedance of the saturated reactor according to Figure 2 The steps are executed in the order shown. The specific execution order of the steps can be determined according to needs, and the present invention does not limit this.

[0105] The above is a method for calculating the input impedance of a saturated reactor broadband equivalent circuit model provided by one or more embodiments of the present invention. Based on the same idea, the present invention also provides a corresponding device for calculating the input impedance of a saturated reactor broadband equivalent circuit model, such as Figure 7 shown.

[0106] Figure 7 A schematic diagram of an input impedance calculation device for a wide-band equivalent circuit model of a saturated reactor provided by the present invention, the device 700 comprises:

[0107] The equivalent module 701 is used to convert the broadband equivalent circuit model of the saturated reactor in the converter valve into a passive two-port network connected to a load.

[0108] The decoupling module 702 is used to perform a decoupling equivalent operation on the inductance containing mutual inductance in the passive two-port network to obtain a broadband equivalent circuit model of the saturated reactor after decoupling.

[0109] The first determination module 703 is used to treat each element except the load in the broadband equivalent circuit model of the decoupled saturated reactor as a two-port, and determine the transmission parameter matrix of each two-port.

[0110] The second determining module 704 is used to obtain a transmission parameter matrix of the passive two-port network according to the two-port cascade principle and the transmission parameter matrix of each two-port.

[0111] The third determination module 705 is used to determine the input impedance of the broadband equivalent circuit model of the saturated reactor according to the relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current.

[0112] Regarding the specific limitations of the input impedance calculation device of the wide-band equivalent circuit model of a saturated reactor, please refer to the limitations of the input impedance calculation method of the wide-band equivalent circuit model of a saturated reactor mentioned above, which will not be repeated here. Each module in the above-mentioned input impedance calculation device of the wide-band equivalent circuit model of a saturated reactor can be fully or partially implemented by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above-mentioned modules.

[0113] The present invention also provides a computer-readable storage medium, which stores a computer program, which can be used to execute the above Figure 2 A method for calculating the input impedance of a wide-band equivalent circuit model of a saturated reactor is provided.

[0114] The present invention also provides Figure 8 The structural diagram of the computer device shown in FIG. Figure 8 As shown in the figure, at the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory, and may also include other hardware required for the business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 2 A method for calculating the input impedance of a wide-band equivalent circuit model of a saturated reactor is provided.

[0115] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided by the present invention can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0116] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the present invention.

Claims

1. A method for calculating the input impedance of a broadband equivalent circuit model of a saturated reactor, characterized in that: include: The broadband equivalent circuit model of the saturable reactor in the converter valve is equivalent to a passive two-port network connected to a load; Perform decoupling equivalent operation on the inductor containing mutual inductance in the passive two-port network to obtain a broadband equivalent circuit model of the decoupled saturated reactor; Each element except the load in the broadband equivalent circuit model of the decoupled saturated reactor is regarded as a two-port, and the transmission parameter matrix of each two-port is determined; According to the two-port cascade principle and the transmission parameter matrix of each two-port, the transmission parameter matrix of the passive two-port network is obtained; According to the relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current, the input impedance of the broadband equivalent circuit model of the saturated reactor is determined.

2. The method according to claim 1, characterized in that The decoupling equivalent operation is the process of converting a circuit containing mutual inductance into an equivalent circuit without mutual inductance. For a T-connected circuit containing mutual inductance, the equivalent circuit after decoupling is a circuit composed of three inductors without mutual inductance.

3. The method according to claim 1, characterized in that The two ports in the broadband equivalent circuit model of the decoupled saturated reactor include the two-port NR1 corresponding to the resistor R1, the two-ports NL1-M and NL2-M corresponding to the inductors L1-M and L2-M, the two-port NC1_M composed of the capacitor C1 and the mutual inductance M in series, the two-ports NR2, NR3 and NR4 corresponding to the resistors R2, R3 and R4, the two-ports NL3 and NL4 corresponding to the self-inductances L3 and L4, the two-port NR5||L5 corresponding to the resistor R5 and the self-inductance L5 in parallel, and the two-ports NC2 and NC3 corresponding to the capacitors C2 and C3; The transmission parameter matrix of each two-port is: in, represents the transmission parameter matrix of two-port NR1; represents the transmission parameter matrix of the two-port NL1-M, ω represents the frequency of the input voltage in the broadband equivalent circuit model of the decoupled saturated reactor; represents the transmission parameter matrix of the two-port NC1_M; represents the transmission parameter matrix of the two-port NL2-M; It represents the two-port NR2; represents the transmission parameter matrix of the two-port NL3; represents the transmission parameter matrix of two-port NR3; represents the transmission parameter matrix of the two-port NL4; represents the transmission parameter matrix of two-port NR4; represents the transmission parameter matrix of the two-port NC2; represents the transmission parameter matrix of two-port NR5||L5; represents the transmission parameter matrix of the two-port NC3.

4. The method according to claim 1, characterized in that: According to the two-port cascade principle and the transmission parameter matrix of each two-port, the transmission parameter matrix of the passive two-port network is obtained, including: According to the two-port cascade principle, the transmission parameter matrices of the two ports are multiplied according to the cascade order of the two ports in the broadband equivalent circuit model of the decoupled saturated reactor to obtain the transmission parameter matrix of the passive two-port network.

5. The method according to claim 1, characterized in that According to the relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current, the input impedance of the broadband equivalent circuit model of the saturated reactor is determined, including: According to the relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current, and the relationship between the output voltage, input voltage and load resistance, the calculation formula of the input impedance of the broadband equivalent circuit model of the saturated reactor is determined; Substituting each element of the transmission parameter matrix of the passive two-port network into the calculation formula, the input impedance of the broadband equivalent circuit model of the saturated reactor is obtained.

6. The method according to claim 5, characterized in that The transmission parameter matrix A of the passive two-port network is: Among them, A 11 , A 12 , A 21 , A 22 is the element of the transmission parameter matrix A of the passive two-port network, that is, the transmission parameter of the passive two-port network; The relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current is: U1=A 11 U2+A 12 (-I2); I1=A 12 U2+A 22 (-I2); Among them, U1 represents the input voltage, I1 represents the input current, I2 represents the output current, U2 represents the output voltage, U2=-R6I2, R6 is the load resistance; The calculation formula of the input impedance of the broadband equivalent circuit model of the saturated reactor is:

7. The method according to claim 5, characterized in that The method further comprises: When self-inductance is added to the broadband equivalent circuit model of the saturated reactor, a transmission parameter matrix of two ports corresponding to the self-inductance is obtained; According to the position of the added self-inductance in the broadband equivalent circuit model of the saturated reactor, according to the cascade position of the two ports corresponding to the self-inductance; Determine the transmission parameter matrix of the passive two-port network according to the cascade position of the two ports corresponding to the self-inductance; Substitute each element of the transmission parameter matrix of the passive two-port network into the calculation formula of the input impedance of the broadband equivalent circuit model of the saturated reactor to determine the input impedance of the broadband equivalent circuit model of the saturated reactor.

8. A device for calculating input impedance of a broadband equivalent circuit model of a saturated reactor, characterized in that: include: An equivalent module is used to convert a broadband equivalent circuit model of a saturated reactor in a converter valve into a passive two-port network connected to a load; A decoupling module is used to perform a decoupling equivalent operation on the inductor containing mutual inductance in the passive two-port network to obtain a broadband equivalent circuit model of the saturated reactor after decoupling; A first determination module is used to treat each element except the load in the broadband equivalent circuit model of the decoupled saturated reactor as a two-port, and determine the transmission parameter matrix of each two-port; A second determination module is used to obtain a transmission parameter matrix of a passive two-port network according to a two-port cascade principle and a transmission parameter matrix of each two-port; The third determination module is used to determine the input impedance of the broadband equivalent circuit model of the saturated reactor according to the relationship between the transmission parameter matrix of the passive two-port network and the input voltage, input current, output voltage and output current.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

10. A computer device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method according to any one of claims 1 to 7 is implemented.

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