A method for calculating the effective value of inductance current of a four-port active bridge converter

Abstract

The application discloses a kind of four-port active bridge converter QAB (quad active bridge) inductance current effective value calculation method. In view of four-port active full-bridge converter model complexity, there is no general expression of inductance current effective value derived in time domain state at present, and the inductance current effective value of four-port active bridge converter is very important for evaluating the loss of four-port active bridge converter. The method combines the Y-type equivalent circuit of four-port active bridge converter, uses square wave function to replace the port voltage of conversion, and obtains the general expression of four-port active bridge converter four-port inductance current effective value after calculation and arrangement. The general expression of four-port active bridge converter inductance current disclosed in the method has high accuracy, and can also be extended to more-port multi-active bridge converter MAB. It provides data support for loss evaluation of four-port active bridge converter and multi-active bridge converter.

Description

Technical Field

[0001] This invention belongs to the field of active bridge converter technology, specifically relating to a method for calculating the effective value of inductor current in a four-port active bridge converter. Background Technology

[0002] Four-port active bridge converters (QABs) offer advantages such as full isolation, bidirectional power flow, high efficiency, and low weight, making them widely used in electric vehicles, aerospace, marine, and power systems. However, because the current flowing through the inductors at the four ports of a QAB is an irregular alternating current, and there is cross-coupling at the four ports, calculating the effective value of the inductor current becomes extremely complex. Since the effective value of the inductor current is directly related to the power loss of a QAB, determining a general expression for the effective value of the inductor current is of significant practical importance for evaluating the power loss of a QAB.

[0003] Previously, the general expression for the inductor current of a four-port active bridge converter was obtained approximately in the frequency domain. Since only the fundamental frequency or low-order harmonics are considered in the frequency domain, the accuracy of the general expression for the inductor current of the four-port active bridge converter is not high. This makes it an urgent problem to solve how to obtain a general expression for the effective value of the inductor current of a four-port active bridge converter in the time domain. Summary of the Invention

[0004] In view of this, the present invention provides a method for calculating the effective value of the inductor current of a four-port active bridge converter, which solves the problem of the lack of a general expression for the effective value of the inductor current of a four-port active bridge converter in the time domain, and improves the accuracy of the general expression for the effective value of the inductor current of a four-port active bridge converter.

[0005] To achieve the above-mentioned technical effects, the technical solution provided by the present invention is as follows:

[0006] In a first aspect, the present invention provides a method for calculating the effective value of the inductor current of a four-port active bridge converter, comprising the following steps:

[0007] Based on the Y-type equivalent circuit of the four-port active bridge converter, the calculation models of voltage, current and equivalent series inductance of the four ports of the transformer when referred to the same port are obtained.

[0008] Based on the calculation model of voltage, current and equivalent series inductance, the calculation model of the midpoint voltage of the Y-type equivalent circuit is obtained according to the superposition theorem.

[0009] Based on the midpoint voltage calculation model, the inductance current calculation model of the transformer four-port is obtained by calculus when the four-port is reduced to the same port;

[0010] The port voltage calculation model is obtained by using square wave function to replace the port voltage of the four-port active bridge converter;

[0011] Based on the inductance current calculation model and the port voltage calculation model, the inductance current instantaneous value calculation model of the four-port active bridge converter is obtained by calculus;

[0012] The inductance current effective value general calculation model of the four-port active bridge converter is obtained by integrating the square of the inductance current instantaneous value calculation model in a switching cycle, and the inductance current effective value calculation is realized based on the general calculation model.

[0013] Further, when reduced to the port 1 side, the expressions of the voltage, current and equivalent series inductance calculation models are as follows:

[0014] Voltage calculation model:

[0015]

[0016] In the formula, , , is the voltage of the transformer port 2, port 3 and port 4 before reduction, , , is the voltage of the transformer port 2, port 3 and port 4 reduced to the port 1 side, is the turns ratio of the transformer port 1 winding and the port 2 winding, is the turns ratio of the transformer port 1 winding and the port 3 winding, is the turns ratio of the transformer port 1 winding and the port 4 winding

[0017] Current calculation model:

[0018]

[0019] In the formula, , , is the current of the transformer port 2, port 3 and port 4 before reduction, , , is the current of the transformer port 2, port 3 and port 4 reduced to the port 1 side;

[0020] Equivalent series inductance calculation model:

[0021]

[0022] wherein, , , Ls2, Ls3, Ls4are the equivalent series inductances of transformer ports 2, 3, 4, respectively, referred to port 1 side, , , Ls2, Ls3, Ls4are the equivalent series inductances of transformer ports 2, 3, 4, respectively, referred to port 1 side.

[0023] Further, the expression of the midpoint voltage calculation model is as follows:

[0024]

[0025] wherein, Vmidis the midpoint voltage of the Y-type equivalent circuit of the four-port active bridge converter, Ls1is the equivalent inductance of port 1, Ls2is the equivalent inductance of port 2, Ls3is the equivalent inductance of port 3, Ls4is the equivalent inductance of port 4, Vt1is the voltage of transformer port 1.

[0026] Further, the equivalent inductances of the midpoint voltage calculation model are calculated according to the following formula:

[0027]

[0028] wherein, Ls1is the equivalent series inductance of port 1.

[0029] Further, the expression of the inductance current calculation model of the transformer four-port is as follows:

[0030]

[0031]

[0032]

[0033]

[0034] wherein, It is the current of transformer port 1.

[0035] Further, the replacement of the port voltage of the four-port active bridge converter with the square wave function includes replacing the voltage of the transformer port with the product of the square wave with an amplitude of 0.5 and a period of 2T and the port voltage of the four-port active bridge converter, and the expression of the obtained port voltage calculation model is as follows:

[0036]

[0037]

[0038]

[0039]

[0040] wherein, is the port 1 voltage of the four-port active bridge converter, is the square wave function, is the port 2 voltage of the four-port active bridge converter, is the phase shift angle between port 2 and port 1 of the four-port active bridge converter, whose value is greater than -1 and less than 1, is half of the switching period of the four-port active bridge converter, is the port 3 voltage of the four-port active bridge converter, is the phase shift angle between port 3 and port 1 of the four-port active bridge converter, whose value is greater than -1 and less than 1, is the port 4 voltage of the four-port active bridge converter, is the phase shift angle between port 4 and port 1 of the four-port active bridge converter, whose value is greater than -1 and less than 1.

[0041] Further, the expression of the inductance current instantaneous value calculation model of the four-port active bridge converter is as follows:

[0042]

[0043]

[0044]

[0045]

[0046] wherein, is the triangular wave with the amplitude of and the period of .

[0047] Further, the expression of the inductance current effective value general calculation model of the four-port active bridge converter is as follows:

[0048]

[0049] wherein, is the inductance current effective value, and the subscript is the port number, is the inherent current, is the transfer current, is the frequency.

[0050] Further, the calculation expressions of the inherent current and the transfer current are as follows:

[0051]

[0052] wherein, is the port of the four-port active bridge converter is the voltage of the port 1, , is the phase shift angle of the port and the port , , is the equivalent inductance of the port , and the calculation expression is as follows:

[0053]

[0054] wherein, is the equivalent series inductance of the port reduced to the port 1, wherein is the port number.

[0055] Further, the general calculation model of the effective value of the inductance current of the four-port active bridge converter is used to obtain the general calculation expression of the effective value of the inductance current of the multi-active bridge converter, as follows:

[0056]

[0057] wherein, is the port number of the multi-active bridge converter.

[0058] In a second aspect, the present application further provides an inductance current effective value calculation device of a four-port active bridge converter, comprising:

[0059] a first calculation module, configured to obtain a calculation model of the voltage, the current and the equivalent series inductance of the transformer four-port reduced to the same port according to a Y-type equivalent circuit of the four-port active bridge converter;

[0060] a second calculation module, configured to obtain a calculation model of the midpoint voltage of the Y-type equivalent circuit according to the superposition theorem based on the calculation model of the voltage, the current and the equivalent series inductance;

[0061] a third calculation module, configured to obtain a calculation model of the inductance current of the transformer four-port reduced to the same port by means of calculus based on the calculation model of the midpoint voltage;

[0062] a fourth calculation module, configured to obtain a calculation model of the port voltage by replacing the port voltage of the four-port active bridge converter with a square wave function;

[0063] The fifth calculation module is configured to obtain an inductor current instantaneous value calculation model of the four-port active bridge converter through differential calculation based on the inductor current calculation model and the port voltage calculation model;

[0064] The sixth calculation module is configured to obtain a general calculation model of the effective value of the inductor current of the four-port active bridge converter by integrating the square of the inductor current instantaneous value calculation model in one switching cycle, and to calculate the effective value of the inductor current based on the general calculation model.

[0065] Correspondingly, the present application further provides a computer device, characterized in that the device comprises a processor and a memory:

[0066] The memory is configured to store a computer program and send instructions of the computer program to the processor.

[0067] The processor is configured to execute the method for calculating the effective value of the inductor current of the four-port active bridge converter according to the instructions of the computer program.

[0068] Correspondingly, the present application further provides a computer readable storage medium, characterized in that the computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the method for calculating the effective value of the inductor current of the four-port active bridge converter according to any one of the first aspect.

[0069] In summary, the present application provides a method for calculating the effective value of the inductor current of the four-port active bridge converter, which comprises obtaining the calculation model of the voltage, current and equivalent series inductance of the transformer four-port reduced to the same port according to the Y-type equivalent circuit of the four-port active bridge converter, obtaining the calculation model of the midpoint voltage of the Y-type equivalent circuit according to the superposition theorem, obtaining the calculation model of the inductor current of the transformer four-port reduced to the same port through differential calculation, replacing the calculation model of the voltage of the transformer four-port with a square wave function, obtaining the calculation model of the inductor current instantaneous value of the four-port active bridge converter through differential calculation, integrating the square of the calculation model of the inductor current instantaneous value in one switching cycle to obtain the general calculation model of the effective value of the inductor current of the four-port active bridge converter, and calculating the effective value of the inductor current based on the general calculation model. The present application proposes a general expression of the effective value of the inductor current of the four-port active bridge converter in the time domain state, and the general expression of the effective value of the inductor current of the four-port active bridge converter proposed by the present application only ignores the equivalent series resistance, the excitation resistance and the excitation inductance, so the accuracy of the general expression of the effective value of the inductor current of the four-port active bridge converter proposed by the present application is higher than that of the expression obtained in the frequency domain state, and the general expression of the effective value of the inductor current of the four-port active bridge converter proposed by the present application can more accurately guide the power loss evaluation of the four-port active bridge converter. BRIEF DESCRIPTION OF DRAWINGS

[0070] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0071] Figure 1 A flow chart of a method for calculating the effective value of inductor current of a four-port active bridge converter provided by the embodiment of the present application;

[0072] Figure 2 A circuit model diagram of a method for calculating the effective value of inductor current of a four-port active bridge converter provided by the embodiment of the present application;

[0073] Figure 3 A Y-type equivalent circuit model diagram of a four-port active bridge converter of a method for calculating the effective value of inductor current of a four-port active bridge converter provided by the embodiment of the present application;

[0074] Figure 4 A square wave waveform diagram of a method for calculating the effective value of inductor current of a four-port active bridge converter provided by the embodiment of the present application;

[0075] Figure 5 A triangular wave waveform diagram of a method for calculating the effective value of inductor current of a four-port active bridge converter provided by the embodiment of the present application. DETAILED DESCRIPTION

[0076] In order to make the purpose, features and advantages of the present application more obvious and easy to understand, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the following described embodiments are only some of the embodiments of the present application, and all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0077] The purpose of the present application is to provide a method for calculating the effective value of inductor current of a four-port active bridge converter, which can accurately calculate the effective value of inductor current of a four-port active bridge converter, and can be extended to more-port multi-active bridge converters, providing data support for loss evaluation of four-port active bridge converters and multi-active bridge converters.

[0078] In order to make the above purpose, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0079] Figure 1is a flow chart of a four-port active bridge converter inductance current effective value calculation method of an embodiment of the application; Figure 2 is a circuit model diagram of a four-port active bridge converter inductance current effective value calculation method of an embodiment of the application; Figure 3 is a four-port active bridge converter Y-type equivalent circuit model diagram of a four-port active bridge converter inductance current effective value calculation method of an embodiment of the application; Figure 4 is a square wave waveform diagram of a four-port active bridge converter inductance current effective value calculation method of an embodiment of the application; Figure 5 is a triangular wave waveform diagram of a four-port active bridge converter inductance current effective value calculation method of an embodiment of the application; in combination Figures 1-5 , the application comprises the following steps:

[0080] S1: According to the Y-type equivalent circuit of the four-port active bridge converter, obtain the voltage, current and equivalent series inductance calculation model of the transformer four-port when reduced to the same port;

[0081] S2: Based on the voltage, current and equivalent series inductance calculation model, obtain the midpoint voltage calculation model of the Y-type equivalent circuit according to the superposition theorem;

[0082] S3: Based on the midpoint voltage calculation model, obtain the inductance current calculation model of the transformer four-port when reduced to the same port through calculus;

[0083] S4: Replace the port voltage of the four-port active bridge converter with a square wave function to obtain the port voltage calculation model;

[0084] S5: Based on the inductance current calculation model and the port voltage calculation model, obtain the inductance current instantaneous value calculation model of the four-port active bridge converter through calculus calculation;

[0085] S6: Integrate the square of the inductance current instantaneous value calculation model in a switching cycle to obtain the inductance current effective value general calculation model of the four-port active bridge converter, and realize inductance current effective value calculation based on the general calculation model.

[0086] The embodiment provides a four-port active bridge converter inductance current effective value calculation method, which proposes a four-port active bridge converter inductance current effective value general expression in a time domain state, and the four-port active bridge converter inductance current effective value general expression proposed in the application only ignores the equivalent series resistance, the excitation resistance and the excitation inductance, so that the accuracy of the four-port active bridge converter inductance current effective value general expression proposed in the application is higher than that of the expression obtained in a frequency domain state, and the four-port active bridge converter inductance current effective value general expression proposed in the application can more accurately guide the power loss evaluation of the four-port active bridge converter.

[0087] In a preferred embodiment of the present application, step S1 specifically comprises:

[0088] S10: Obtain the Y-type equivalent circuit of the four-port active bridge converter according to the Y-type equivalent circuit of the transformer, and the transformer port voltage is calculated to the side of port 1, and the specific formula is:

[0089]

[0090] In the formula, , , is the voltage of transformer port 2, port 3, and port 4 before calculation, , , is the voltage of transformer port 2, port 3, and port 4 calculated to the side of port 1, is the turns ratio of the port 1 winding of the transformer to the port 2 winding, is the turns ratio of the port 1 winding of the transformer to the port 3 winding, is the turns ratio of the port 1 winding of the transformer to the port 4 winding.

[0091] S11: The transformer port current is calculated to the side of port 1, and the specific formula is:

[0092]

[0093] , , is the current of transformer port 2, port 3, and port 4 before calculation, , , is the current of transformer port 2, port 3, and port 4 calculated to the side of port 1.

[0094] S12: The equivalent series inductance of the transformer port is calculated to the side of port 1, and the specific formula is:

[0095]

[0096] , , is the equivalent series inductance of transformer port 2, port 3, and port 4 before calculation, , , is the equivalent series inductance of transformer port 2, port 3, and port 4 calculated to the side of port 1. The Y-type equivalent circuit of the four-port active bridge converter ignores the excitation resistance and the excitation inductance, and ignores the equivalent series resistance of the wire and the switch tube.

[0097] In a preferred embodiment of the present application, step S2 specifically comprises:

[0098] S20: According to the superposition theorem, write the Kirchhoff voltage equation when port 1 acts alone, and the specific expression is:

[0099]

[0100] In the formula, Ls is the equivalent series inductance of port 1, V1 is the voltage of transformer port 1, I1 is the current of transformer port 1. Ls2, Ls3 and Ls4 are the parallel of the equivalent series inductance of transformer port 2, port 3 and port 4, which are reduced to port 1 side.

[0101] S21: According to the midpoint voltage when port 1 acts alone, the specific expression is:

[0102]

[0103] In the formula, Vmid1 is the midpoint voltage when port 1 acts alone.

[0104] S22: According to the superposition theorem, write the Kirchhoff voltage equation when port 2 acts alone, and the specific expression is:

[0105]

[0106] In the formula, Ls2, Ls3 and Ls4 are the parallel of the equivalent series inductance of transformer port 2, port 3 and port 1, which are reduced to port 1 side.

[0107] S23: According to the midpoint voltage when port 2 acts alone, the specific expression is:

[0108]

[0109] In the formula, Vmid2 is the midpoint voltage when port 2 acts alone.

[0110] S24: According to the superposition theorem, write the Kirchhoff voltage equation when port 3 acts alone, and the specific expression is:

[0111]

[0112] In the formula, Ls2, Ls3 and Ls4 are the parallel of the equivalent series inductance of transformer port 2, port 4 and port 1, which are reduced to port 1 side.

[0113] S25: According to the midpoint voltage when port 3 acts alone, the specific expression is:

[0114]

[0115] wherein, is the midpoint voltage when port 3 acts alone.

[0116] S26: According to the superposition theorem, the column write Kirchhoff voltage equation is written when port 4 acts alone, and the specific expression is:

[0117]

[0118] wherein, is the parallel of the equivalent series inductance of transformer port 2, port 3 and port 1 reduced to port 1 side.

[0119] S27: According to the midpoint voltage when port 4 acts alone, the specific expression is:

[0120]

[0121] wherein, is the midpoint voltage when port 4 acts alone.

[0122] S28: The coefficient in front of the respective port voltage when each port acts alone is simplified to the equivalent inductance, and the specific expression is:

[0123]

[0124] wherein, is the equivalent inductance of port 1, is the equivalent inductance of port 2, is the equivalent inductance of port 3, is the equivalent inductance of port 4.

[0125] S29: The midpoint voltage of the Y-type equivalent circuit of the four-port active bridge converter is obtained by the superposition theorem, and the specific expression is:

[0126]

[0127] wherein, is the midpoint voltage of the Y-type equivalent circuit of the four-port active bridge converter.

[0128] In a preferred embodiment of the present application, step S3 specifically comprises:

[0129] S30: The differential expression of the inductance current of port 1 is obtained by calculus, and the specific expression is:

[0130]

[0131] S31: Obtain the differential expression of the inductive current of port 2 reduced to port 1 by calculus, and the specific expression is:

[0132]

[0133] S32: Obtain the differential expression of the inductive current of port 3 reduced to port 1 by calculus, and the specific expression is:

[0134]

[0135] S33: Obtain the differential expression of the inductive current of port 4 reduced to port 1 by calculus, and the specific expression is:

[0136]

[0137] In a preferred embodiment of the present application, step S4 specifically comprises:

[0138] S40: Replace the voltage on the side of port 1 of the transformer with the product of a square wave with an amplitude of 0.5 and a period of 2T and the voltage of port 1 of the four-port active bridge converter, and the specific expression is:

[0139]

[0140] In the formula, is the voltage of port 1 of the four-port active bridge converter, is a square wave function.

[0141] S41: Replace the voltage on the side of port 2 of the transformer reduced to port 1 with the product of a square wave with an amplitude of 0.5 and a period of 2T and the voltage of port 2 of the four-port active bridge converter, and the specific expression is:

[0142]

[0143] In the formula, is the voltage of port 2 of the four-port active bridge converter, is the phase shift angle of port 2 and port 1 of the four-port active bridge converter, and its value is greater than -1 and less than 1, is half of the switching period of the four-port active bridge converter.

[0144] S42: Replace the voltage on the side of port 3 of the transformer reduced to port 1 with the product of a square wave with an amplitude of 0.5 and a period of 2T and the voltage of port 3 of the four-port active bridge converter, and the specific expression is:

[0145]

[0146] In the formula, is the voltage of port 3 of the four-port active bridge converter, The phase shift angle of the port 3 of the four-port active bridge converter with respect to the port 1 is greater than -1 and less than 1.

[0147] S43: The voltage on the port 4 side of the transformer, which is reduced to the port 1, is replaced by the product of a square wave with an amplitude of 0.5 and a period of 2T and the voltage on the port 4 of the four-port active bridge converter, and the specific expression is:

[0148]

[0149] In the formula, is the voltage on the port 4 of the four-port active bridge converter, The phase shift angle of the port 4 of the four-port active bridge converter with respect to the port 1 is greater than -1 and less than 1.

[0150] In a preferred embodiment of the present application, step S5 specifically comprises:

[0151] S50: According to the volt-second balance theorem, the inductance current expression of the port 1 of the four-port active bridge converter is obtained by integrating the differential expression of the inductance current of the port 1 of the four-port active bridge converter, and the specific expression is:

[0152]

[0153] In the formula, is a triangular wave with an amplitude of and a period of .

[0154] S51: According to the volt-second balance theorem, the inductance current expression of the port 2 of the four-port active bridge converter is obtained by integrating the differential expression of the inductance current of the port 2 of the four-port active bridge converter, and the specific expression is:

[0155]

[0156] S52: According to the volt-second balance theorem, the inductance current expression of the port 3 of the four-port active bridge converter is obtained by integrating the differential expression of the inductance current of the port 3 of the four-port active bridge converter, and the specific expression is:

[0157]

[0158] S53: According to the volt-second balance theorem, the inductance current expression of the port 4 of the four-port active bridge converter is obtained by integrating the differential expression of the inductance current of the port 4 of the four-port active bridge converter, and the specific expression is:

[0159]

[0160] In a preferred embodiment of the present application, step S6 specifically comprises:

[0161] S60: Simplify the integral by using the integral formula of the triangle wave, and the specific formula is:

[0162]

[0163] S61: According to the half-cycle symmetry of the inductor current of the four-port active bridge converter, the square of the inductor current expression of port 1 of the four-port active bridge converter is integrated in half a cycle to obtain the effective value expression of the inductor current of port 1 of the four-port active bridge converter, and the specific expression is:

[0164]

[0165] S62: According to the half-cycle symmetry of the inductor current of the four-port active bridge converter, the square of the inductor current expression of port 2 of the four-port active bridge converter is integrated in half a cycle to obtain the effective value expression of the inductor current of port 2 of the four-port active bridge converter, and the specific expression is:

[0166]

[0167] S63: According to the half-cycle symmetry of the inductor current of the four-port active bridge converter, the square of the inductor current expression of port 3 of the four-port active bridge converter is integrated in half a cycle to obtain the effective value expression of the inductor current of port 3 of the four-port active bridge converter, and the specific expression is:

[0168]

[0169] S64: According to the half-cycle symmetry of the inductor current of the four-port active bridge converter, the square of the inductor current expression of port 4 of the four-port active bridge converter is integrated in half a cycle to obtain the effective value expression of the inductor current of port 4 of the four-port active bridge converter, and the specific expression is:

[0170]

[0171] S65: The general expression of the effective value of the inductor current of the four-port active bridge converter is obtained by summarizing the rules, and the specific expression is:

[0172]

[0173] In the formula, is the port number, is the inherent current, which is irrelevant to the phase shift angle, is the transfer current, which is relevant to the phase shift angle.

[0174] In further embodiments of the present application, the specific expression of the inherent current and the transferred current is:

[0175]

[0176] wherein is the port of the four-port active bridge converter is the voltage of the port 1, , is the port and the port is the phase shift angle of the port , is the equivalent inductance of the port , and the specific expression is:

[0177]

[0178] wherein is the port is the equivalent series inductance of the port 1, , wherein is the number of ports.

[0179] In further embodiments of the present application, the general expression of the effective value of the inductance current of the multi-active bridge converter can be obtained by generalization, and the specific expression is:

[0180]

[0181] wherein is the number of ports of the multi-active bridge converter.

[0182] Based on the above embodiments, the general expression of the effective value of the inductance current of the four-port active bridge converter proposed by the present application in the time domain state can be directly generalized to the general expression of the effective value of the inductance current of the multi-active bridge converter, and the basic forms are the same, except that the number of terms of the expression will increase with the increase of the number of ports of the multi-active bridge converter. Therefore, the general expression of the effective value of the inductance current proposed by the present application provides data support for the power loss evaluation of the multi-active bridge converter.

[0183] Based on the same inventive concept, the embodiments of the present application also provide an inductance current effective value calculation device of a four-port active bridge converter for implementing the inductance current effective value calculation method of the four-port active bridge converter. The implementation scheme for solving the problem provided by the system is similar to the implementation scheme described in the above method, and therefore the specific limitations in the following embodiments of the inductance current effective value calculation device of the four-port active bridge converter can be referred to the limitations of the inductance current effective value calculation method of the four-port active bridge converter in the above text, which will not be repeated here.

[0184] The embodiment provides a kind of four-port active bridge converter inductance current effective value computing device, comprising:

[0185] First computing module, for obtaining the voltage, current and equivalent series inductance calculation model of transformer four-port when being reduced to the same port according to the Y-type equivalent circuit of four-port active bridge converter;

[0186] Second computing module, for obtaining the midpoint voltage calculation model of Y-type equivalent circuit according to superposition theorem based on voltage, current and equivalent series inductance calculation model;

[0187] Third computing module, for obtaining the inductance current calculation model of transformer four-port when being reduced to the same port based on midpoint voltage calculation model by calculus;

[0188] Fourth computing module, for obtaining port voltage calculation model by using square wave function to replace the port voltage of four-port active bridge converter;

[0189] Fifth computing module, for obtaining the inductance current instantaneous value calculation model of four-port active bridge converter by calculus calculation based on inductance current calculation model and port voltage calculation model;

[0190] Sixth computing module, for obtaining the inductance current effective value general calculation model of four-port active bridge converter by integrating the square of inductance current instantaneous value calculation model in a switching cycle, and inductance current effective value calculation is realized based on general calculation model.

[0191] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the above-mentioned division of each functional unit and module is exemplified, and in actual application, the above-mentioned functions can be completed by different functional units and modules according to needs, that is, the internal structure of the system is divided into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment can be integrated in one processing unit, or each unit can exist physically, or two or more units can be integrated in one unit, and the integrated unit can be realized in the form of hardware or software. In addition, the specific name of each functional unit and module is only for easy distinction, and does not limit the protection scope of the application. The specific working process of the unit and module in the system can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

[0192] The embodiment of the present application further provides a computer device, comprising a memory and a processor and a computer program stored in the memory, and when the computer program is executed on the processor, a four-port active bridge converter inductance current effective value calculation method in any of the above methods is realized.

[0193] The computer device can be a desktop computer, a notebook computer, a palm computer, a cloud server and the like. The computer device can comprise, but is not limited to, a processor and a memory.

[0194] The processor can be a central processing unit (CPU), and can also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor.

[0195] The memory can be an internal storage unit of the computer device in some embodiments, for example, a hard disk or a memory of the computer device. The memory can also be an external storage device of the computer device in other embodiments, for example, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card and the like. Further, the memory can comprise both the internal storage unit and the external storage device of the computer device. The memory is used to store an operating system, application programs, a boot loader, data and other programs, for example, program codes of the computer program, etc. The memory can also be used to temporarily store data that has been output or will be output.

[0196] The embodiment of the present application further provides a computer readable storage medium, which stores a computer program, and when the computer program is executed by a processor, a four-port active bridge converter inductance current effective value calculation method in any of the above methods is realized.

[0197] In this embodiment, the integrated unit, if implemented in the form of a software functional unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the computer program for instructing the related hardware to complete all or part of the processes in the above-described embodiment methods can be stored in a computer readable storage medium. The computer program can be executed by a processor to implement the steps of the above-described various method embodiments. The computer program includes computer program code, which can be in the form of source code, object code, executable file or some intermediate form. The computer readable medium at least includes any entity or device capable of carrying the computer program code to the photographing device / terminal equipment, recording medium, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium. For example, U disk, mobile hard disk, magnetic disk or optical disk, etc. In some jurisdictions, according to legislation and patent practice, the computer readable medium can not be an electrical carrier signal and a telecommunication signal.

[0198] In the above-described embodiments, the description of each embodiment has its own focus, and the parts not described or recorded in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0199] Those skilled in the art can appreciate that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether the functions are implemented in hardware or software depends on the specific application and design constraints of the technical solutions. The skilled person can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0200] In the embodiments disclosed in the present application, it should be understood that the disclosed apparatus / terminal equipment and methods can be implemented in other ways. For example, the apparatus / terminal equipment embodiments described above are only schematic, for example, the division of the modules or units is only a logical function division, and actual implementation can have another division manner, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed each other can be indirect coupling or communication connection through some interfaces, devices or units, and can be electrical, mechanical or other forms.

[0201] The above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced by equivalent features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method of calculating the effective value of inductance current of a four-port active bridge converter, characterized by, The method comprises the following steps: According to the Y-type equivalent circuit of the four-port active bridge converter, a voltage, current and equivalent series inductance calculation model of the transformer four-port when reduced to the same port is obtained; Based on the voltage, current and equivalent series inductance calculation model, a midpoint voltage calculation model of the Y-type equivalent circuit is obtained according to the superposition theorem; Based on the midpoint voltage calculation model, an inductance current calculation model of the transformer four-port when reduced to the same port is obtained through calculus; The port voltage of the four-port active bridge converter is replaced by a square wave function to obtain a port voltage calculation model; Based on the inductance current calculation model and the port voltage calculation model, an inductance current instantaneous value calculation model of the four-port active bridge converter is obtained through calculus calculation; The square of the inductance current instantaneous value calculation model is integrated in a switching cycle to obtain a general calculation model of the inductance current effective value of the four-port active bridge converter, and the inductance current effective value calculation is realized based on the general calculation model.

2. The method of claim 1, wherein, When reduced to the port 1 side, the expression of the voltage, current and equivalent series inductance calculation model is as follows: The voltage calculation model is as follows: ； wherein , , V2, V3, V4 are voltages of the transformer ports 2, 3, 4 referred to port 1, , , V2, V3, V4 are voltages of the transformer ports 2, 3, 4 referred to port 1, is the turns ratio of the transformer port 1 winding to the port 2 winding, is the turns ratio of the transformer port 1 winding to the port 3 winding, is the turns ratio of the transformer port 1 winding to the port 4 winding The current calculation model is as follows: ； wherein , , is the current of the transformer port 2, 3, 4, which is referred to port 1, , , is the current of the transformer port 2, 3, 4, which is referred to port 1. The equivalent series inductance calculation model is as follows: ； wherein , , Ls2, Ls3, Ls4 are the equivalent series inductances of the transformer ports 2, 3, 4 referred to port 1, , , Ls2, Ls3, Ls4 are the equivalent series inductances of the transformer ports 2, 3, 4 referred to port 1.

3. The method of claim 2, wherein, The expression of the midpoint voltage calculation model is as follows: ； wherein is the midpoint voltage of the four-port active bridge converter Y-equivalent circuit, is the equivalent inductance of port 1, is the equivalent inductance of port 2, is the equivalent inductance of port 3, is the equivalent inductance of port 4, is the voltage of transformer port 1.

4. The method of claim 3, wherein, The equivalent inductance of the midpoint voltage calculation model is calculated according to the following formula: ； In the formula, Ls is the equivalent series inductance of port 1.

5. The method of claim 4, wherein, The expression of the inductance current calculation model of the transformer four-port is as follows: ； ； ； ； In the formula, is the current at the transformer port 1.

6. The method of claim 5, wherein, Replacing the port voltage of the four-port active bridge converter with a square wave function comprises replacing the voltage of the transformer port with the product of a square wave with an amplitude of 0.5 and a period of 2T and the port voltage of the four-port active bridge converter, and the expression of the obtained port voltage calculation model is as follows: ； ； ； ； wherein Vp1 is the port 1 voltage of the four-port active bridge converter, is a square wave function, Vp2 is the port 2 voltage of the four-port active bridge converter, is the phase shift angle of the port 2 and port 1 of the four-port active bridge converter, which has a value greater than -1 and less than 1, is half of the switching period of the four-port active bridge converter, Vp3 is the port 3 voltage of the four-port active bridge converter, is the phase shift angle of the port 3 and port 1 of the four-port active bridge converter, which has a value greater than -1 and less than 1, Vp4 is the port 4 voltage of the four-port active bridge converter, is the phase shift angle of the port 4 and port 1 of the four-port active bridge converter, which has a value greater than -1 and less than 1.

7. The method of claim 6, wherein, The expression of the inductance current instantaneous value calculation model of the four-port active bridge converter is as follows: ； ； ； ； In the formula, is a triangular wave having an amplitude of and a period of .

8. The method of claim 7, wherein, The expression of the inductance current effective value general calculation model of the four-port active bridge converter is as follows: ； In the formula, is the effective value of the inductive current, the subscript is the port number, is the intrinsic current, is the transfer current, is the frequency.

9. The method of claim 8, wherein, The calculation expressions of the intrinsic current and the transfer current are as follows: ； wherein is the port of the four-port active bridge converter is the voltage of port 1, , is the port and port is the phase shift angle of port , is the equivalent inductance of port is calculated as follows: ； where Ls,1 is the equivalent series inductance of port 1, Ls,1 is the equivalent series inductance of port 1, Ls,1 is the equivalent series inductance of port 1, Np is the number of ports; Vj is the voltage at port j of a four-port active bridge converter normalized to port 1; φ is the phase shift angle between port 1 and port φ is the phase shift angle between port 1 and port φ is the phase shift angle between port 1 and port φ is the phase shift angle between port 1 and port Ls,1 is the equivalent series inductance of port 1, Ls,1 is the equivalent series inductance of port 1, Ls,1 is the equivalent series inductance of port 1, Nt is the turns ratio of the transformer port 1 winding to port Nt is the turns ratio of the transformer port 1 winding to port Ls,1 is the equivalent series inductance of port 1, Ls,1 is the equivalent series inductance of port 1, 10. The method of claim 8, wherein, Based on the inductance current effective value general calculation model of the four-port active bridge converter, a general expression of the inductance current effective value of the multi-active bridge converter is obtained, as follows: ； In the formula, is the number of ports of the multi-active bridge converter.

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