Modulation method and device of multi-active bridge converter and electronic equipment

Abstract

The invention provides a modulation method and device for a multi-active bridge converter and electronic equipment, and the method comprises the steps: obtaining a target modulation parameter according to an obtained initial parameter; wherein the parameter updating period corresponding to the target modulation parameter comprises 2n + 3 pulse signals, the pulse signals appear in a positive and negative alternating mode, and n is an integer larger than or equal to 0; the duty ratio of the first pulse signal to the last pulse signal in the 2n + 3 pulse signals is half of the duty ratio in the initial parameters, and the duty ratios of the other pulse signals are equal to the duty ratio in the initial parameters; the external shift ratio of any one of the 2n + 3 pulse signals is equal to the external shift ratio in the initial parameters. And modulating the converter by using a preset modulation strategy according to the target modulation parameter. Therefore, in a single parameter updating period, the winding current and the excitation current of the multi-active bridge transformer do not have any transient steady state direct current bias.

Description

Technical Field

[0001] The present application relates to the technical field of converter modulation, and particularly relates to a modulation method, device, and electronic device for a multi-active bridge converter. Background Art

[0002] The multi-active bridge (MAB) converter has the characteristics of multi-DC port interconnection, flexible and controllable power flow, and high dynamic response. During the operation of the MAB converter, it is necessary to modulate the MAB converter so that the MAB converter operates according to specific parameters.

[0003] Currently, the general generic phase shift (GPS) modulation method is usually used to modulate the MAB converter. Among them, GPS modulation includes single phase shift (SPS) modulation or extended soft switching phase shift (ESSPS) modulation.

[0004] However, both of the above two modulation methods have the situation of transient-state DC bias, resulting in low transient performance of the MAB converter. Summary of the Invention

[0005] The present application provides a modulation method, device, and electronic device for a multi-active bridge converter to solve the problem of low transient performance of the MAB converter.

[0006] In a first aspect, the present application provides a modulation method for a multi-active bridge converter, and the method includes:

[0007] Obtain target modulation parameters according to the acquired initial parameters;

[0008] Wherein, the parameter update period corresponding to the target modulation parameters includes 2n + 3 pulse signals, the pulse signals appear alternately positive and negative, and n is an integer greater than or equal to 0; the duty cycles of the first pulse signal and the last pulse signal among the 2n + 3 pulse signals are both half of the duty cycle in the initial parameters, and the duty cycles of other pulse signals are all equal to the duty cycle in the initial parameters; the external phase shift ratio of any one of the 2n + 3 pulse signals is equal to the external phase shift ratio in the initial parameters;

[0009] Modulate the multi-active bridge converter using a pre-set modulation strategy according to the target modulation parameters.

[0010] In a possible implementation manner, the duration of the parameter update period is 2m + 3 times the half-switching period when modulating the multi-active-bridge converter, where m is an integer greater than or equal to n.

[0011] In a possible implementation manner, the duration of the parameter update period is 2s + 3 times the half-switching period when modulating the multi-active-bridge converter, where s is a non-integer greater than or equal to n.

[0012] In a possible implementation manner, the end moment of the non-zero voltage and current in the k-th parameter update period is earlier than or equal to the start moment of the non-zero voltage and current in the (k + 1)-th parameter update period.

[0013] In a possible implementation manner, the last pulse signal in the k-th parameter update period and the first pulse signal in the (k + 1)-th parameter update period have opposite polarities, so that the magnetic flux density when modulating the multi-active-bridge converter is opposite in the k-th parameter update period and the (k + 1)-th parameter update period.

[0014] In a possible implementation manner, the initial parameters further include a parameter update trigger threshold, a first coefficient, and a second coefficient; wherein, the parameter update trigger threshold is obtained according to the external shift ratio, the duty cycle, the first coefficient, and the second coefficient; the first coefficient is n, and the second coefficient is 2m + 3 or 2s + 3;

[0015] Obtaining the target modulation parameters according to the obtained initial parameters includes:

[0016] When the condition of the parameter update trigger threshold is satisfied, update the external shift ratio, the duty cycle, the parameter update period, the first coefficient, and the second coefficient in the modulation parameters to obtain the target modulation parameters.

[0017] In a possible implementation manner, the preset modulation strategy is a general phase-shift modulation strategy with 2N - 1 scheduling degrees of freedom, and the general phase-shift modulation strategy includes a single phase-shift modulation strategy or an extended soft-switching phase-shift modulation strategy, where N is the number of H-bridges in the multi-active-bridge converter.

[0018] In a second aspect, the present application provides a modulation device for a multi-active-bridge converter, including:

[0019] A processing module, configured to obtain target modulation parameters according to the obtained initial parameters;

[0020] Among them, the parameter update period corresponding to the target modulation parameter includes 2n + 3 pulse signals, the pulse signals appear alternately positive and negative, and n is an integer greater than or equal to 0; the duty cycles of the first pulse signal and the last pulse signal among the 2n + 3 pulse signals are both half of the duty cycle in the initial parameters, and the duty cycles of the other pulse signals are all equal to the duty cycle in the initial parameters; the external shift ratio of any one of the 2n + 3 pulse signals is equal to the external shift ratio in the initial parameters.

[0021] A modulation module, configured to modulate the multi-active bridge converter according to the target modulation parameter by using a pre-set modulation strategy.

[0022] In a third aspect, an embodiment of the present application provides an electronic device, including: a memory, a processor;

[0023] The memory stores computer-executable instructions;

[0024] The processor executes the computer-executable instructions stored in the memory, so that the processor executes the above first aspect and / or various possible implementation manners of the first aspect.

[0025] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which computer-executable instructions are stored, and when the computer-executable instructions are executed by a processor, they are used to implement the above first aspect and / or various possible implementation manners of the first aspect.

[0026] In a fifth aspect, an embodiment of the present application provides a computer program product, including a computer program, and when the computer program is executed by a processor, it implements the above first aspect and / or various possible implementation manners of the first aspect.

[0027] The modulation method, device and electronic device of the multi-active bridge converter provided by the present application, the method includes: obtaining a target modulation parameter according to the acquired initial parameter; among them, the parameter update period corresponding to the target modulation parameter includes 2n + 3 pulse signals, the pulse signals appear alternately positive and negative, and n is an integer greater than or equal to 0; the duty cycles of the first pulse signal and the last pulse signal among the 2n + 3 pulse signals are both half of the duty cycle in the initial parameters, and the duty cycles of the other pulse signals are all equal to the duty cycle in the initial parameters; the external shift ratio of any one of the 2n + 3 pulse signals is equal to the external shift ratio in the initial parameters. Modulating the converter according to the target modulation parameter by using a pre-set modulation strategy. In this way, within a single parameter update period, there is no any transient or steady-state DC bias in the winding current and exciting current of the multi-active bridge transformer. Description of the Drawings

[0028] The accompanying drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with this application, and are used together with the specification to explain the principles of this application.

[0029] Figure 1 Schematic diagram of the H-bridge high-frequency voltage during GPS modulation of a MAB converter provided for an embodiment of this application;

[0030] Figure 2 Schematic flow diagram of a modulation method for a multi-active-bridge converter provided for this application;

[0031] Figure 3 Schematic diagram of the H-bridge high-frequency voltage during EH-GPS modulation of a MAB converter provided for an embodiment of this application;

[0032] Figure 4 Another schematic diagram of the H-bridge high-frequency voltage during EH-GPS modulation of a MAB converter provided for an embodiment of this application;

[0033] Figure 5 Schematic diagram of the H-bridge high-frequency voltage and current timing at the j-th port during EH-GPS modulation of a MAB converter provided for an embodiment of this application;

[0034] Figure 6 Another schematic diagram of the H-bridge high-frequency voltage during EH-GPS modulation of a MAB converter provided for an embodiment of this application;

[0035] Figure 7(a) is a schematic diagram of the winding voltage of a GPS modulation provided for an embodiment of this application;

[0036] Figure 7(b) is a schematic diagram of the winding current of a GPS modulation provided for an embodiment of this application;

[0037] Figure 7(c) is a schematic diagram of the exciting current of a GPS modulation provided for an embodiment of this application;

[0038] Figure 7(d) is a schematic diagram of the hysteresis loop of a GPS modulation provided for an embodiment of this application;

[0039] Figure 8(a) is a schematic diagram of the winding voltage of an EH-GPS modulation provided for an embodiment of this application;

[0040] Figure 8(b) is a schematic diagram of the winding current of an EH-GPS modulation provided for an embodiment of this application;

[0041] Figure 8(c) is a schematic diagram of the exciting current of an EH-GPS modulation provided for an embodiment of this application;

[0042] Figure 8(d) is a schematic diagram of the hysteresis loop of an EH-GPS modulation provided for an embodiment of this application;

[0043] Figure 9 Schematic diagram of a specific implementation manner of EH-GPS modulation provided by an embodiment of the present application;

[0044] Figure 10 Schematic diagram of the timing of a main carrier generation and synchronization module provided by an embodiment of the present application;

[0045] Figure 11 Schematic diagram of the timing of a sub-carrier module provided by an embodiment of the present application;

[0046] Figure 12 Schematic diagram of the timing of unit carrier and parameter calculation module 1 and unit carrier and parameter calculation module 2 provided by an embodiment of the present application;

[0047] Figure 13 Schematic diagram of the timing of a gate signal generation module provided by an embodiment of the present application;

[0048] Figure 14 External shift ratio under GPS modulation provided by an embodiment of the present application Schematic diagram of the time-domain waveform during update;

[0049] Figure 15 External shift ratio under EH-GPS modulation provided by an embodiment of the present application Schematic diagram of the time-domain waveform during update;

[0050] Figure 16 External shift ratio under EH-GPS modulation provided by an embodiment of the present application Schematic diagram of the hysteresis loop during update;

[0051] Figure 17 Duty cycle under GPS modulation provided by an embodiment of the present application Schematic diagram of the time-domain waveform during update;

[0052] Figure 18 Duty cycle under EH-GPS modulation provided by an embodiment of the present application Schematic diagram of the time-domain waveform during update;

[0053] Figure 19 Duty cycle under EH-GPS modulation provided by an embodiment of the present application Schematic diagram of the hysteresis loop during update;

[0054] Figure 20 Schematic diagram of the time-domain waveform during update of the number n of full-duty-cycle switching periods inserted under EH-GPS modulation provided by an embodiment of the present application;

[0055] Figure 21Schematic diagram of the hysteresis loop when the number of full-duty cycle switching periods n inserted under EH-GPS modulation is updated;

[0056] Figure 22 Schematic diagram of the time-domain waveform when the parameter update period coefficient R under EH-GPS modulation is updated;

[0057] Figure 23 Schematic diagram of the hysteresis loop when the parameter update period coefficient R under EH-GPS modulation is updated;

[0058] Figure 24 Schematic diagram of the time-domain waveform when the number of full-duty cycle switching periods n inserted and the parameter update period coefficient R under EH-GPS modulation are updated simultaneously;

[0059] Figure 25 Schematic diagram of the hysteresis loop when the number of full-duty cycle switching periods n inserted and the parameter update period coefficient R under EH-GPS modulation are updated simultaneously;

[0060] Figure 26 The actual switching frequency under EH-GPS modulation provided by the embodiments of the present application Schematic diagram of the time-domain waveform when updated;

[0061] Figure 27 The actual switching frequency under EH-GPS modulation provided by the embodiments of the present application Schematic diagram of the hysteresis loop when updated;

[0062] Figure 28 Another actual switching frequency under EH-GPS modulation provided by the embodiments of the present application Schematic diagram of the time-domain waveform when updated;

[0063] Figure 29 Another actual switching frequency under EH-GPS modulation provided by the embodiments of the present application Schematic diagram of the hysteresis loop when updated;

[0064] Figure 30 Schematic diagram of the time-domain waveform when switching from EH-GPS modulation to GPS modulation provided by the embodiments of the present application;

[0065] Figure 31 Schematic diagram of the hysteresis loop when switching from EH-GPS modulation to GPS modulation provided by the embodiments of the present application;

[0066] Figure 32 Schematic diagram of the structure of an electronic device provided by the embodiments of the present application.

[0067] Through the above-mentioned drawings, specific embodiments of the present application have been shown, and will be described in more detail hereinafter. These drawings and written descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by reference to specific embodiments. Detailed Description of Specific Embodiments

[0068] Here, exemplary embodiments will be described in detail, and examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0069] The MAB converter is an isolated multi-port DC-DC converter, which has the characteristics of multi-DC-port interconnection, electrical isolation, flexible and controllable power flow, and high dynamic response.

[0070] The MAB converter consists of N H-bridge converters and an N-winding high-frequency transformer. The number of ports N ≥ 2: when N = 2, it is a Dual Active Bridge (DAB) converter; when N = 3, it is a Triple Active Bridge (TAB) converter; when N = 4, it is a Quadruple Active Bridge (QAB) converter, and so on.

[0071] The MAB converter has N DC ports, and its DC voltage and DC current need to match the power supply or load connected to the ports respectively. The phase and duty cycle of the N AC square-wave voltages of the transformer are controlled by N H-bridges, and the peak value of the square-wave voltage is clamped by the DC voltage of the H-bridge.

[0072] All parameters such as voltages, currents, and inductances hereinafter are values after transformer turns reduction.

[0073] For the j-th (j = 1,..., N) H-bridge in the MAB converter, it includes 4 semiconductor power switches. The corresponding gate switch signals are respectively , , , .

[0074] The function of the j-th (j = 1,..., N) H-bridge is: the j-th (j = 1,..., N) H-bridge, under the modulation of , , , , converts the DC voltage ( ) is transformed into a high-frequency square wave with adjustable duty cycle ( ). The high-frequency square wave voltages output by N H-bridges are simultaneously applied to the N windings of the transformer. The phase difference ( ) between the high-frequency square wave voltages is used to control the alternating current ( ), and then the power flow between the H-bridges is controlled, thereby realizing the control of the power transfer of the MAB converter. )

[0075] For the MAB converter, considering the π-shaped equivalent circuit model of the multi-winding transformer with exciting inductance, through represents the inductance connected between terminals j and i, which is related to the power transferred between ports and is called the power transfer inductance; is the equivalent independent exciting inductance of the winding.

[0076] The sum of the independent exciting inductance currents of is equal to the actual exciting current ( ). and can be obtained through transformation from the self-inductance mutual inductance matrix

[0077] Let the DC voltage of H-bridge j be , and the DC voltage of H-bridge i be . During GPS modulation, the high-frequency square wave output by H-bridge j is , with a frequency , a duty cycle of the half-switching period , and an external shift ratio ; the high-frequency square wave output by H-bridge i is , with a frequency , a duty cycle of the half-switching period , and an external shift ratio . At this time, the difference in the external shift ratio between H-bridge j and H-bridge i is , and , as can be seen in Figure 1 . Figure 1 This is a schematic diagram of the high-frequency voltage of the H-bridge during GPS modulation of the MAB converter provided by the embodiment of the present application.

[0078] Therefore, the degrees of freedom during GPS modulation are respectively , , …, ; let the external shift ratio of the H-bridge with the most advanced phase be , then the range of the external shift ratio is limited to …, .

[0079] When the GPS modulation is performed, the power transferred from H-bridge j to H-bridge i is:

[0080] ;

[0081] The average transferred power of the MAB converter during GPS modulation can be seen in Table 1 as follows:

[0082] Table 1

[0083]

[0084] Since the normal DC bias of the MAB converter is defined as: there is no bias, that is, no DC component, in the AC winding current at steady state. In the π-equivalent circuit model of a multi-winding transformer considering the exciting inductance, the AC current at the port should not have a DC component at steady state, and the following two specific requirements need to be met simultaneously: First, the current on should not have a DC component at steady state; Second, considering the exciting state of the transformer core, the current on should not have a DC component at steady state.

[0085] The GPS modulation methods of the MAB converter, namely SPS modulation and ESSPS modulation, both have the following two problems, which affect their performance and practical application implementation:

[0086] (1) Even if the input parameters are constant, there is always a transient bias in the exciting current, and the time constant is large, and the transient time is long, resulting in increased transformer magnetic bias and AC / DC current, reduced transient performance of the MAB converter, and increased losses.

[0087] (2) The overlap of the AC voltage and current in adjacent switching cycles is inevitable in time. Therefore, when the working state and modulation parameters change, especially when the external shift ratio changes, abnormal pulse voltages will be generated, resulting in uncontrollable power transfer; at the same time, due to the change of modulation parameters, the time integral of the square-wave voltage is asymmetric, and a significant transient bias is generated in the winding current, reducing the transient and steady-state performance of the MAB converter and increasing losses.

[0088] Therefore, the common GPS modulation methods have the situation of transient and steady-state DC bias, making the transient performance of the MAB converter relatively low.

[0089] In some implementations, based on SPS modulation or ESSPS modulation, between the turn-off moments of the lower transistor of the previous bridge and the upper transistor of the rear bridge and the turn-on moments of the upper transistor of the previous bridge and the lower transistor of the rear bridge in each H-bridge of the MAB converter in the previous switching cycle, zero-voltage states with fixed or variable durations are respectively added. To improve the dynamic response speed of the modulation method and make there be no starting transient overcurrent on the winding.

[0090] However, the circuit model of this modulation method does not consider the transient and steady-state biases of the exciting current and the core magnetic flux density.

[0091] In some other implementations, based on ESSPS modulation, different duty cycles are set for the first half cycle and the second half cycle of the switching period; different external phase shift ratios are set for the first half cycle and the second half cycle of the switching period; phase-shifted zero-voltage sequences with different duration ratios are added at the end of the first half cycle and the second half cycle of the switching period. These direct modulation parameters are calculated from the key input parameters (external phase shift ratio, duty cycle, global frequency reduction coefficient, DC voltage sampling value) according to the current bias and magnetic flux density bias principle. When the input modulation parameters change, this modulation method has no transient winding current bias and magnetic bias, and has small delay and high accuracy in power transfer.

[0092] However, there are still some problems with this modulation method: (1) Based on ESSPS modulation, the duty cycle parameter is calculated from the DC voltage detection value, so it is greatly affected by the dynamic response, error, and noise of DC voltage sampling; (2) It cannot flexibly control the duty cycle parameters of each port separately; (3) The average transferred power is less than that of ESSPS modulation and SPS modulation with the same parameters, and the performance and efficiency during steady-state operation may not be optimal; (4) It does not consider the operating conditions where the switching frequency may change.

[0093] Based on this, the present application provides a modulation method for a multi-active-bridge converter. Based on the GPS modulation method, the input modulation parameters in each parameter update period are set to be unchanged, and each parameter update period includes an odd number of half-switching periods of pulses greater than or equal to 3; the duty cycles of each port in the first half-switching period and the last half-switching period are half of the duty cycles of the other half-switching periods, and the external phase shift ratios of each port in all half-switching periods are equal to the input external phase shift ratio. In this way, within one parameter switching period, the AC voltage is axisymmetric about the midpoint of the parameter switching period, and the sub-circuit current between ports j and i of the MAB transformer and the independent exciting inductor current are centrosymmetric about the midpoint of the parameter switching period. Therefore, the modulation method of the present application can make the winding current and exciting current of the MAB transformer have no transient or steady-state DC bias.

[0094] The technical solution of the present application and how the technical solution of the present application solves the above technical problems will be described in detail below with specific embodiments. These specific embodiments below can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below with reference to the accompanying drawings.

[0095] It should be noted that the modulation method of the multi-active-bridge converter provided in the embodiments of this application is hereinafter referred to as the End-Halved Generic Phase Shift (EH-GPS) modulation method of the multi-active-bridge converter in the following embodiments.

[0096] Figure 2 It is a schematic flowchart of a modulation method for a multi-active-bridge converter provided in this application. As Figure 2 shown, the method includes:

[0097] S201. Obtain target modulation parameters according to the acquired initial parameters.

[0098] Among them, the parameter update period corresponding to the target modulation parameters includes 2n + 3 pulse signals, the pulse signals appear alternately positive and negative, and n is an integer greater than or equal to 0; the duty cycles of the first pulse signal and the last pulse signal among the 2n + 3 pulse signals are both half of the duty cycle in the initial parameters, and the duty cycles of the other pulse signals are all equal to the duty cycle in the initial parameters; the external phase shift ratio of any one of the 2n + 3 pulse signals is equal to the external phase shift ratio in the initial parameters.

[0099] It should be understood that within one parameter update period, the input modulation parameters remain unchanged.

[0100] S202. Modulate the converter using a pre-set modulation strategy according to the target modulation parameters.

[0101] Figure 3 It is a schematic diagram of the H-bridge high-frequency voltage during EH-GPS modulation of an MAB converter provided in an embodiment of this application.

[0102] As Figure 3 shown, the external phase shift ratio , where ; the duty cycle ; the actual switching frequency .

[0103] In the embodiments of this application, the relationship between the parameter update period and the half-switching period is represented by a parameter update period coefficient. The duration of each parameter update period is , where R is the parameter update period coefficient. Each of the above input modulation parameters remains unchanged, and each parameter update period contains 2n + 3 half-switching periods. The duty cycles of each port in the first half-switching period and the last half-switching period are half of the input duty cycle, and the duty cycles of each port from the second half-switching period to the second-to-last half-switching period are equal to the input duty cycle. The external phase shift ratios of each port in all half-switching periods are equal to the input external phase shift ratio.

[0104] In the embodiments of the present application, the length of the parameter update period is not necessarily an integer multiple of the half-switching period length, and the parameter update period includes the following two possible implementations:

[0105] In one possible implementation, the duration of the parameter update period is 2m + 3 times the half-switching period when modulating the multi-active-bridge converter, where m is an integer greater than or equal to n.

[0106] That is, the number of half-switching periods included in the parameter update period is an integer. For example, as shown above Figure 3 shown, the parameter update period includes 2n + 3 half-switching periods.

[0107] In another possible implementation, the duration of the parameter update period is 2s + 3 times the half-switching period when modulating the multi-active-bridge converter, where s is a non-integer greater than or equal to n.

[0108] Figure 4 FIG. Another schematic diagram of the H-bridge high-frequency voltage during EH-GPS modulation of the MAB converter provided by the embodiments of the present application.

[0109] Figure 4 Different from Figure 3 is that the number of half-switching periods included in the parameter update period is non-integer, and other parameters are the same.

[0110] As shown above Figure 3 and Figure 4 shown, when n = 0, the minimum parameter update period can be less than or equal to 1.5 actual switching periods, and there is no overlap between adjacent parameter update periods. EH-GPS modulation does not require DC voltage detection and does not require approximation or estimation of any parameters; it only takes at most 1.5 actual switching periods to complete the modulation execution and output the required power. Therefore, the method of the present application can improve the dynamic response speed of modulation execution to a certain extent.

[0111] Taking Figure 3 shown high-frequency voltage schematic diagram as an example, for the k-th parameter update period of the j-th port, the timing starting from the rising edge of the AC voltage in the first half-switching period is as Figure 5 shown, Figure 5 FIG. A schematic diagram of the H-bridge high-frequency voltage and current timing of the j-th port during EH-GPS modulation of the MAB converter provided by the embodiments of the present application.

[0112] In Figure 5 , the output voltage timing of the k-th parameter update period of the j-th port is as shown in Table 2 below.

[0113] Table 2

[0114]

[0115] To improve the power transfer efficiency, the length of the parameter update period should be as short as possible. Therefore, the time length of the interval [4n + 7] may be negative, that is, the interval [4n + 6] may span into the next parameter update period.

[0116] In the embodiment of the present application, the end time of the non-zero voltage current in the k-th parameter update period is earlier than or equal to the start time of the non-zero voltage current in the (k + 1)-th parameter update period.

[0117] As Figure 5 shown, the sum of the time lengths of the interval [1] and the interval [4n + 7] is , and the value must be greater than or equal to 0, that is .

[0118] In addition, the current end point of the -th parameter update period of any two ports, that is, the end time of the interval [4n + 6], and the current start point of the -th parameter update period, that is, the start time of the interval [2], must not overlap. That is to say, when the length of the interval [4n + 7] is negative, the minimum value of the length of the interval [1] needs to be greater than or equal to the maximum value of the opposite number of the length of the interval [4n + 7]. That is, the minimum value of the length of the interval [1] needs to satisfy the following formula (1) with respect to the maximum value of the opposite number of the length of the interval [4n + 7].

[0119] (1)

[0120] The value of the parameter update period coefficient R needs to satisfy the following formula (2):

[0121] (2)

[0122] When the preset modulation strategy is GPS modulation of any outer shift ratio and duty cycle, the right side of the inequality of the limiting condition in formula (2) must be less than or equal to n + 1.5. That is, R ≥ n + 1.5.

[0123] Based on Figure 5 and Table 2, it can be seen that the intervals [2] and [4n + 6], [3] and [4n + 5], and [4] together constitute a voltage waveform that is symmetric in the time domain, and the positive voltage integrals of the intervals [2] and [4n + 6], [3] and [4n + 5] are both half of the negative voltage integral of the interval [4]. Therefore, the AC voltages of the five intervals [2], [3], [4], [4n + 5], and [4n + 6] are axisymmetric with respect to the midpoint of the interval [4]; for the ports individually excited by the voltage source and Sub-circuit current and the independent excitation inductance current First rise from 0, then fall, then rise, and finally return to 0, showing central symmetry with respect to the midpoint of interval 【4】. That is, integrating the voltage or current within a parameter update period results in 0. Therefore, in the modulation method provided by the embodiments of the present application, there is no transient DC bias in the transformer winding current, excitation current, and magnetic flux density.

[0124] In the present application, the last pulse signal in the k-th parameter update period and the first pulse signal in the (k + 1)-th parameter update period have opposite polarities, so that the magnetic flux density during the modulation of the multi-active-bridge converter is opposite in the k-th parameter update period and the (k + 1)-th parameter update period.

[0125] Take Figure 3 as an example. Figure 6 FIG. is a schematic diagram of the H-bridge high-frequency voltage during the EH-GPS modulation of the MAB converter provided by the embodiments of the present application.

[0126] The hysteresis loss power of the multi-winding high-frequency transformer core of the MAB converter , where the hysteresis frequency is the number of times the hysteresis loop closes in 1 second, and the hysteresis loss energy is proportional to the area enclosed by each small hysteresis loop closure or large hysteresis loop closure.

[0127] In the current GPS modulation method, when modulating the MAB transformer, the winding voltage is shown in FIG. 7(a), the winding current is shown in FIG. 7(b), the excitation current is shown in FIG. 7(c), and the hysteresis loop is shown in FIG. 7(d). FIG. 7(a) is a schematic diagram of the winding voltage of a GPS modulation provided by the embodiments of the present application. FIG. 7(b) is a schematic diagram of the winding current of a GPS modulation provided by the embodiments of the present application. FIG. 7(c) is a schematic diagram of the excitation current of a GPS modulation provided by the embodiments of the present application. FIG. 7(d) is a schematic diagram of the hysteresis loop of a GPS modulation provided by the embodiments of the present application.

[0128] As shown in FIG. (d), the B-H hysteresis loop of the MAB transformer closes at the large loop in each actual switching period, and the hysteresis loss energy , where is the hysteresis loss energy corresponding to the area of the large loop.

[0129] Therefore, the existing GPS modulation method has hysteresis loss when modulating the MAB converter.

[0130] In Figure 6Based on the H-bridge high-frequency voltage shown, for the EH-GPS modulation method provided in this application, when modulating the MAB transformer, the winding voltage is as shown in Fig. 8(a), the winding current is as shown in Fig. 8(b), the exciting current is as shown in Fig. 8(c), and the hysteresis loop is as shown in Fig. 8(d). Fig. 8(a) is a schematic diagram of the winding voltage of an EH-GPS modulation provided by an embodiment of this application. Fig. 8(b) is a schematic diagram of the winding current of an EH-GPS modulation provided by an embodiment of this application. Fig. 8(c) is a schematic diagram of the exciting current of an EH-GPS modulation provided by an embodiment of this application. Fig. 8(d) is a schematic diagram of the hysteresis loop of an EH-GPS modulation provided by an embodiment of this application.

[0131] As shown in Fig. 8(a) and Fig. 8(b), during EH-GPS modulation, when the polarity of the last pulse signal in the k-th parameter update period is opposite to that of the first pulse signal in the (k + 1)-th parameter update period, the non-zero voltage current in the -th parameter update period is opposite to the non-zero voltage current in the -th parameter update period, and the magnetic flux density waveform during EH-GPS modulation is opposite within two parameter update periods.

[0132] The B-H hysteresis loop of the MAB transformer closes 2 times at the small loop and times at the large loop in every two parameter update periods, and the hysteresis loss is lower than the GPS modulation loss .

[0133] The hysteresis loss is as shown in formula (3):

[0134] (3)

[0135] Wherein, is the hysteresis loss energy corresponding to the area of the small loop.

[0136] For example, when n = 0 and R = 1.5, the hysteresis loss is as shown in formula (4):

[0137] (4)

[0138] Exemplarily, , then , when, at the same actual switching frequency, DC voltage, external shift ratio, and duty cycle, the hysteresis loss of EH-GPS modulation is approximately 59% of that of GPS modulation.

[0139] In this way, compared with the existing GPS modulation, by setting the polarities of the last pulse signal in the k-th parameter update period and the first pulse signal in the (k + 1)-th parameter update period to be opposite, the hysteresis loss is small. Therefore, the EH-GPS modulation of the present application can reduce the hysteresis loss.

[0140] In the present application, the initial parameters further include a parameter update trigger threshold, a first coefficient, and a second coefficient.

[0141] As described in the above embodiments, the parameter update trigger threshold is , the first coefficient is n, and the second coefficient is 2m + 3 or 2s + 3.

[0142] Among them, the parameter update trigger threshold is obtained based on the external shift ratio, duty cycle, first coefficient, and second coefficient. Next, the calculation method of the parameter update trigger threshold will be described.

[0143] As Figure 5 and shown in formula (1), since , and , when all ports are in the interval [1] and not in the interval [4n + 6], all winding currents are 0. At this time, the parameters can be updated, and the time range ( ) is:

[0144] (5)

[0145] Among them, is the parameter update trigger threshold. In step S401 described in the above embodiments, when obtaining the target modulation parameters according to the acquired initial parameters, the external shift ratio, duty cycle, parameter update period, first coefficient, and second coefficient in the modulation parameters can be updated to obtain the target modulation parameters when the parameter update trigger threshold is satisfied.

[0146] That is to say, within the time satisfying the above formula (5), the external shift ratio , duty cycle , the number of full-duty-cycle switch periods n inserted, and the parameter update period coefficient R can be updated.

[0147] Based on Figure 3 and Figure 5 shown, between the phases of [1.5π, (2n + 2)π] in each parameter update period, the voltage and current waveforms in the EH-GPS modulation method of the present application are the same as those of the GPS modulation with the same phase. Therefore, within this range, the EH-GPS modulation of the present application can be flexibly switched to the GPS modulation with the same parameters.

[0148] When n = 0 and R = 1.5, the transfer power corresponding to each phase-shifting condition region can be seen in Table 3.

[0149] Table 3

[0150] (H-bridge → H-bridge )

[0151]

[0152]

[0153]

[0154] In the embodiment of the present application, the preset modulation strategy is a general phase-shifting modulation strategy with 2N - 1 scheduling degrees of freedom. The general phase-shifting modulation strategy includes a single phase-shifting modulation strategy or an extended soft-switching phase-shifting modulation strategy, where N is the number of H-bridges in the multi-active-bridge converter.

[0155] When the preset modulation strategy is ESSPS modulation, it is combined into EH-ESSPS modulation.

[0156] In EH-ESSPS modulation, the following conditions are met:

[0157] (1) The zero-voltage switching (ZVS) condition still holds, and the MAB converter is turned on with zero voltage.

[0158] (2) The head and tail of the parameter update period are approximately the conduction and turn-off of zero-current switching (ZCS), further reducing the switching loss.

[0159] (3) The fundamental frequency of the transformer magnetic flux density , winding voltage , winding current is , without even harmonics; the maximum harmonic component is located at .

[0160] (4) The fundamental frequency of the transfer power , port current is ; the maximum harmonic component is located at , and the half-cycle current integral intensity is not greater than that of GPS modulation, so it does not affect the selection of the DC capacitor of the MAB converter.

[0161] In this way, the modulation method provided by the embodiments of the present application can be implemented based on a single-phase-shift modulation strategy or an extended soft-switching phase-shift modulation strategy, making the modulation strategy more flexible to adjust.

[0162] Next, a feasible implementation manner is used to illustrate the EH-GPS modulation method of the present application.

[0163] Figure 9 It is a schematic diagram of a specific implementation manner of EH-GPS modulation provided by the embodiments of the present application.

[0164] It should be noted that in specific applications, the specific implementation of EH-GPS modulation can be realized by a microcontroller such as a single-chip microcomputer or a field programmable gate array (FPGA for short). In Figure 9 each module can be a hardware module or a software module, and the embodiments of the present application do not limit the specific implementation device.

[0165] As Figure 9 shown, the implementation scheme of EH-GPS modulation includes 5 modules, namely: a main carrier generation and synchronization module, a frequency update module, a main parameter update module, a sub-carrier module, and a carrier and gate signal module.

[0166] The external input signal of EH-GPS modulation, that is, the initial parameters in the above embodiments are: the input value of the switching frequency , the input value of the external phase shift ratio , the input value of the duty cycle , the input value of the number of full-duty-cycle switching periods inserted , the input value of the parameter update period coefficient , and the main parameter update trigger threshold , and its value range is shown in the above formula (5). The target modulation parameters of EH-GPS modulation, that is, Figure 9 the output signals shown are the gate drive signals , , , . The remaining signals are internal signals.

[0167] There are trigger and latch relationships between the main carrier generation and synchronization module and the frequency update module, and between the main carrier generation and synchronization module and the main parameter update module. Therefore, the initial values of their output values need to be stored inside the frequency update module and the main parameter update module respectively.

[0168] Next, the functions of each module in EH-GPS modulation are described respectively.

[0169] 1. Main carrier generation and synchronization module

[0170] Figure 10 This is a timing diagram of the main carrier generation and synchronization module provided by the embodiment of the present application.

[0171] As Figure 10 shown, the main carrier signal CR rises with a time slope and has an upper limit ; the sub - carrier selection signal SEL 12 is inverted each time CR returns to zero; the rising edge of the frequency update trigger signal TRF occurs at each zero - crossing moment of CR; the rising edge of the main parameter update trigger signal TRR occurs during the rising stage of the CR signal and at the moment of intersection with the moment of intersection.

[0172] 2. Frequency update module

[0173] The frequency update module is used to store and update the actual switching frequency . Before the system starts running, the initial value of the actual switching frequency is already stored in the frequency update module. At the rising edge of the frequency update trigger signal TRF, the output is updated to the input value .

[0174] 3. Main parameter update module

[0175] The main parameter update module is used to store and update the external shift ratio , duty cycle , the number of full - duty - cycle switching periods inserted , and the parameter update period coefficient . Before the system starts running, the initial values of the above - mentioned parameters are already stored in the frequency update module. At the rising edge of the main parameter update trigger signal TRR, the outputs , , , are respectively updated to the input values , , , .

[0176] 4. Sub - carrier module

[0177] Figure 11 This is a timing diagram of the sub - carrier module provided by the embodiment of the present application.

[0178] As Figure 11 shown, according to the input of the main carrier signal CR and the sub - carrier selection signal SEL 12 , the sub - carrier signals CR1 and CR2 are respectively at the moment when CR returns to zero and SEL12 Starts at 0 and 1, and has an upper limit ; After reaching the upper limit, it resets to zero. Therefore, CR1 and CR2 overlap in time in the case of

[0179] 5. Carrier and gate signal module

[0180] As Figure 9 shown, the carrier and gate signal module includes three parts, namely: unit carrier and parameter calculation module 1, unit carrier and parameter calculation module 2, and gate signal generation module

[0181] Figure 12 This is a timing diagram of a unit carrier and parameter calculation module 1 and a unit carrier and parameter calculation module 2 provided by an embodiment of the present application

[0182] As Figure 12 shown, in the unit carrier and parameter calculation module 1, the unit carrier signal CR j,1 is a triangular wave signal generated by phase-shifting CR1 , with upper and lower limits of , and a continuous phase of , that is half-switching cycles; in the first and last half-switching cycles, the positive comparison signal is , and the negative comparison signal is ; in the remaining middle half-switching cycles, the positive comparison signal is , and the negative comparison signal is ; at other times, the positive comparison signal is 1, and the negative comparison signal is

[0183] In the unit carrier and parameter calculation module 2, the unit carrier signal CR j,2 is a triangular wave signal generated by phase-shifting CR2 , with upper and lower limits of , and a continuous phase of , that is half-switching cycles; in the first and last half-switching cycles, the positive comparison signal is , and the negative comparison signal is ; in the remaining middle half-switching cycles, the positive comparison signal is , and the negative comparison signal is ; at other times, the positive comparison signal is 1, and the negative comparison signal is

[0184] Figure 13 This is a timing diagram of a gate signal generation module provided by an embodiment of the present application

[0185] As Figure 13 ​​As shown, when the unit carrier signal CR j,1 is greater than the positive comparison signal the switching signal S j,1 is 1; when the unit carrier signal CR j,1 is less than the negative comparison signal the switching signal S j,1 is ; when the unit carrier signal CR j,2 is greater than the positive comparison signal the switching signal S j,2 is 1; when the unit carrier signal CR j,2 is less than the negative positive comparison signal the switching signal S j,2 is .

[0186] The switching signals S j,1 and S j,2 are combined to output the gate drive signals , , , , and generate the required winding voltage .

[0187] Combined with the above embodiments, below, taking the MAB converter as a four-active-bridge (QAB) converter as an example, the EH-GPS modulation method of the present application and its implementation effects will be described.

[0188] The physical parameters of the QAB converter are: the turns of the transformer can be reduced to 1; , , , ; the series leakage inductance of each winding ; the T-shaped magnetizing inductance of the transformer , adopting the Preisach hysteresis model (core parameters: coercive force , remanence , saturation magnetic field intensity , saturation magnetic flux density , saturation relative magnetic permeability ).

[0189] Below, the parameter update and dynamic response of the EH-GPS modulation method will be described.

[0190] Taking the update of the external shift ratio as an example, the update of the external shift ratio can include:[[]]

[0191] Among them, the operating parameters include: the actual switching frequency ; the duty cycle , , , ; The out-shift ratio compared to , , ; The number of full-duty-cycle switching periods inserted , parameter update period coefficient . The change in the out-shift ratio update is from updated to .

[0192] Figure 14 is a schematic diagram of the time-domain waveform when the out-shift ratio under GPS modulation in the embodiment of the present application is updated.

[0193] As Figure 14 shown, during GPS modulation, a sudden change in the out-shift ratio will cause a large transient and steady-state bias in the winding current and excitation current.

[0194] Figure 15 is a schematic diagram of the time-domain waveform when the out-shift ratio under EH-GPS modulation in the embodiment of the present application is updated.

[0195] Figure 16 is a schematic diagram of the hysteresis loop when the out-shift ratio under EH-GPS modulation in the embodiment of the present application is updated.

[0196] As Figure 15 and Figure 16 shown, during EH-GPS modulation, when the input value of the out-shift ratio has a step change, the out-shift ratio is updated and executed at the rising edge of TRR, and there is no transient and steady-state bias in both the winding current and the excitation current, and there is no magnetic bias in the transformer and inductor; the delay for completing the modulation execution and outputting the required power is less than .

[0197] Taking the update of the duty cycle as an example, the update of the duty cycle can include:

[0198] Among them, the operating parameters include: the actual switching frequency ; the duty cycle , , ; the out-shift ratio , , , ; the number of full-duty-cycle switching periods inserted , parameter update period coefficient . The duty cycle changes from Updated to 。

[0199] Figure 17 A time-domain waveform diagram of the duty cycle update under GPS modulation provided by an embodiment of the present application when updated.

[0200] As Figure 17 shown, when GPS is modulated, a sudden change in the duty cycle will cause a large transient and steady-state bias in the winding current and exciting current.

[0201] Figure 18 A time-domain waveform diagram of the duty cycle update under EH-GPS modulation provided by an embodiment of the present application when updated.

[0202] Figure 19 A hysteresis loop diagram of the duty cycle update under EH-GPS modulation provided by an embodiment of the present application when updated.

[0203] As Figure 18 and Figure 19 shown, when EH-GPS is modulated, when the input value of the duty cycle steps, the duty cycle is updated and executed at the rising edge of TRR, and there is no transient and steady-state bias in the winding current and exciting current, and there is no magnetic bias in the transformer and inductor; the delay for completing the modulation execution and outputting the required power is less than 。

[0204] When updating the number n of inserted full-duty-cycle switching periods, it may include:

[0205] The operating parameters may include: the actual switching frequency ; the duty cycle 、 、 、 ; the external shift ratio 、 、 、 ; the parameter update period coefficient 。The number n of inserted full-duty-cycle switching periods is updated from Updated to 。

[0206] Figure 20 A time-domain waveform diagram of the update of the number n of inserted full-duty-cycle switching periods under EH-GPS modulation provided by an embodiment of the present application

[0207] Figure 21 A hysteresis loop diagram of the update of the number n of inserted full-duty-cycle switching periods under EH-GPS modulation provided by an embodiment of the present application

[0208] As Figure 20 and Figure 21 shown, during EH - GPS modulation, the input value of the number of full - duty - cycle switch cycles inserted During the step change, the proportion of the number of full - duty - cycle switch cycles inserted Is updated and executed at the rising edge of TRR. There is no transient - steady - state bias in the winding current and the exciting current, and there is no magnetic bias in the transformer and the inductor; the delay for completing the modulation execution and outputting the required power is less than .

[0209] When updating the parameter update period coefficient R, it may include:

[0210] The operating parameters may include: the actual switching frequency ; the duty cycle , , , ; the external shift ratio , , , ; the number of full - duty - cycle switch cycles inserted . The parameter update period coefficient is updated from to .

[0211] Figure 22 FIG. is a schematic diagram of the time - domain waveform when the parameter update period coefficient R is updated under EH - GPS modulation provided by an embodiment of the present application.

[0212] Figure 23 FIG. is a schematic diagram of the hysteresis loop when the parameter update period coefficient R is updated under EH - GPS modulation provided by an embodiment of the present application.

[0213] As Figure 22 and Figure 23 shown, during EH - GPS modulation, the input value of the parameter update period coefficient During the step change, the parameter update period coefficient Is updated and executed at the rising edge of TRR. There is no transient - steady - state bias in the winding current and the exciting current, and there is no magnetic bias in the transformer and the inductor; the delay for completing the modulation execution and outputting the required power is less than .

[0214] When simultaneously updating the number n of full - duty - cycle switch cycles inserted and the parameter update period coefficient R, it may include:

[0215] The operating parameters may include: the actual switching frequency ; the duty cycle , , , ; Compared with the outward shift , , , . The number of full-duty-cycle switching periods inserted is determined by updated to ; At the same time, the parameter update period coefficient is changed from updated to .

[0216] Figure 24 is a schematic diagram of the time-domain waveform when the number n of full-duty-cycle switching periods inserted and the parameter update period coefficient R are updated simultaneously under EH-GPS modulation provided by an embodiment of the present application.

[0217] Figure 25 is a schematic diagram of the hysteresis loop when the number n of full-duty-cycle switching periods inserted and the parameter update period coefficient R are updated simultaneously under EH-GPS modulation provided by an embodiment of the present application.

[0218] As Figure 24 and Figure 25 show, when performing EH-GPS modulation, when the input value of the number of full-duty-cycle switching periods inserted and the input value of the parameter update period coefficient change in a stepped manner simultaneously, the number of full-duty-cycle switching periods inserted and the parameter update period coefficient are updated and executed at the rising edge of TRR, and there is no transient steady-state bias in the winding current and the exciting current, and there is no bias magnetization in the transformer and the inductor; the delay for completing the modulation execution and outputting the required power is less than .

[0219] When updating the actual switching frequency , the following two possible implementations are included:

[0220] In one possible implementation, when, the operating parameters may include: duty cycle , , , ; Compared with the outward shift , , , ; The number of full-duty-cycle switching periods inserted and the parameter update period coefficient . The actual switching frequency is changed from updated to .

[0221] Figure 26The actual switching frequency under EH-GPS modulation provided by the embodiments of the present application Schematic diagram of the time-domain waveform during update.

[0222] Figure 27 The actual switching frequency under EH-GPS modulation provided by the embodiments of the present application Schematic diagram of the hysteresis loop during update.

[0223] As Figure 26 and Figure 27 shown, when under EH-GPS modulation and the input value of the actual switching frequency has a step change, the actual switching frequency is updated and executed at the rising edge of TRF, and there is no transient-state bias in the winding current and the exciting current, and there is no magnetic bias in the transformer and the inductor; the delay for completing the modulation execution and outputting the required power is less than .

[0224] In another possible implementation, when, the operating parameters may include: duty cycle , , , ; external shift ratio , , , ; number of full-duty-cycle switching periods inserted , parameter update period coefficient . The actual switching frequency is updated from to .

[0225] Figure 28 Another schematic diagram of the time-domain waveform during the update of the actual switching frequency under EH-GPS modulation provided by the embodiments of the present application .

[0226] Figure 29 Another schematic diagram of the hysteresis loop during the update of the actual switching frequency under EH-GPS modulation provided by the embodiments of the present application .

[0227] As Figure 28 and Figure 29 shown, when under EH-GPS modulation and the input value of the actual switching frequency has a step change, first the parameter update period coefficient is updated to the value of at the rising edge of TRR; subsequently, the actual switching frequency Updated and executed at the rising edge of the TRF, there is no transient steady-state bias in the winding current and excitation current, and there is no flux bias in the transformer and inductor; the delay to complete the modulation execution and output the required power is less than .

[0228] Next, the hysteresis loss during the actual operation of the EH-GPS modulation will be described.

[0229] The EH-GPS modulation includes the following two possible cases:

[0230] One possible case is when the same and , the operating parameters may include: the actual switching frequency , the external shift ratio , , , , the duty cycle , , , , the number of full-duty-cycle switching cycles inserted , the parameter update cycle coefficient .

[0231] When the same and , the comparison of the hysteresis losses during the actual operation of the EH-GPS modulation and the GPS modulation is shown in Table 5.

[0232] Table 5

[0233]

[0234] As can be seen from Table 5, when the actual switching frequency, the external shift ratio, and the duty cycle are the same, the transmitted power of the EH-GPS modulation is less than that of the GPS modulation, and the hysteresis loss of the EH-GPS modulation is about 57.6% of that of the GPS modulation.

[0235] Another possible case is when the actual switching frequency and the transmitted power are the same, the operating parameters may include: the actual switching frequency ; the duty cycle , , , ; GPS modulation: the external shift ratio , , , ; EH-GPS modulation: the external shift ratio , , , ; the number of full-duty-cycle switching cycles inserted , Parameter update period coefficient .

[0236] When the actual switching frequency and the transfer power are the same, the comparison of the actual operating hysteresis losses between EH-GPS modulation and GPS modulation is shown in Table 6.

[0237] Table 6

[0238]

[0239] As shown in Table 6, when the actual switching frequency and the transfer power are the same, that is, when the transfer power of EH-GPS modulation is equal to the transfer power of GPS modulation, due to the approximate invariance of the switching frequency and the port voltage amplitude, the hysteresis loss of EH-GPS modulation is still about 57.5% of that of GPS modulation.

[0240] Therefore, the EH-GPS modulation method of the present application can reduce the hysteresis loss.

[0241] Next, the case of switching from EH-GPS modulation to GPS modulation will be described.

[0242] When switching from EH-GPS modulation to GPS modulation, it may include:

[0243] The operating parameters may include: actual switching frequency ; duty cycle , , , ; outer shift ratio , , , ; number of full-duty-cycle switching periods inserted , parameter update period coefficient .

[0244] Figure 30 FIG. is a schematic diagram of the time-domain waveform when switching from EH-GPS modulation to GPS modulation provided by an embodiment of the present application.

[0245] Figure 31 FIG. is a schematic diagram of the hysteresis loop when switching from EH-GPS modulation to GPS modulation provided by an embodiment of the present application.

[0246] As Figure 30 and Figure 31 shown, within the phase of the parameter update period, it can be flexibly switched to GPS modulation with the same switching frequency, duty cycle, and outer shift ratio, and there is no transient or steady-state bias in the winding current and the exciting current, and there is no magnetic bias in the transformer and the inductor.

[0247] Figure 32A schematic structural diagram of an electronic device provided by an embodiment of the present application. As Figure 32 shown, the electronic device 370 provided in this embodiment includes: at least one processor 3701 and a memory 3702. Optionally, the device 370 further includes a communication component 3703. Among them, the processor 3701, the memory 3702, and the communication component 3703 are connected through a bus 3704.

[0248] In a specific implementation process, at least one processor 3701 executes computer-executable instructions stored in the memory 3702, so that at least one processor 3701 executes the above method.

[0249] For the specific implementation process of the processor 3701, reference can be made to the above method embodiment, and its implementation principle and technical effects are similar, so they will not be elaborated here in this embodiment.

[0250] In the above embodiment, it should be understood that the processor may be a central processing unit (English: Central Processing Unit, abbreviated: CPU), or other general-purpose processors, digital signal processors (English: Digital Signal Processor, abbreviated: DSP), application specific integrated circuits (English: Application Specific Integrated Circuit, abbreviated: ASIC), etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the method disclosed in combination with the invention can be directly embodied as being executed by a hardware processor, or executed by a combination of hardware and software modules in the processor.

[0251] The memory may include a high-speed memory (Random Access Memory, RAM), and may also include a non-volatile memory (Non-volatile Memory, NVM), such as at least one disk memory.

[0252] The bus may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, the bus in the drawings of the present application is not limited to only one bus or one type of bus.

[0253] The present application also provides a computer program product, including a computer program, which implements the above method when executed by a processor.

[0254] The present application also provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the above method.

[0255] The above-readable storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, a magnetic disk, or an optical disk. The readable storage medium can be any available medium accessible by a general-purpose or special-purpose computer.

[0256] An exemplary readable storage medium is coupled to the processor, enabling the processor to read information from and write information to the readable storage medium. Of course, the readable storage medium can also be a component of the processor. The processor and the readable storage medium can be located in an application specific integrated circuit (ASIC). Of course, the processor and the readable storage medium can also exist as discrete components in a device.

[0257] The division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be indirect couplings or communication connections through some interfaces, devices, or units, and can be in electrical, mechanical, or other forms.

[0258] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0259] In addition, in each embodiment of the present invention, the functional units can be integrated in a processing unit, or each unit can physically exist alone, or two or more units can be integrated in one unit.

[0260] If a function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or a part of this technical solution can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes: USB flash drives, mobile hard disks, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs, etc., all kinds of media that can store program codes.

[0261] Those of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions. The aforementioned program can be stored in a computer-readable storage medium. When this program is executed, it executes the steps including the above method embodiments; and the aforementioned storage medium includes: ROMs, RAMs, magnetic disks, or optical discs, etc., all kinds of media that can store program codes.

[0262] Finally, it should be noted that: after considering the specification and practicing the invention disclosed herein, those skilled in the art will easily think of other implementation manners of the present invention. The present invention is intended to cover any variations, uses, or adaptations of the present invention, and these variations, uses, or adaptations follow the general principles of the present invention and include common general knowledge or conventional technical means in the technical field not disclosed in the present invention. It is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A modulation method for a multi-active-bridge converter, characterized in that The method includes: Obtaining target modulation parameters according to the acquired initial parameters; Among them, the parameter update period corresponding to the target modulation parameters includes 2n + 3 pulse signals, the pulse signals appear alternately as positive and negative, and n is an integer greater than or equal to 0; the duty cycles of the first pulse signal and the last pulse signal among the 2n + 3 pulse signals are both half of the duty cycle in the initial parameters, and the duty cycles of the other pulse signals are all equal to the duty cycle in the initial parameters; the external shift ratio of any one of the 2n + 3 pulse signals is equal to the external shift ratio in the initial parameters; Modulating the multi-active bridge converter according to the target modulation parameters by using a preset modulation strategy.

2. The method according to claim 1, wherein The duration of the parameter update period is 2m + 3 times the half-switching period when modulating the multi-active bridge converter, and m is an integer greater than or equal to n.

3. The method according to claim 1, characterized in that, The duration of the parameter update period is 2s + 3 times the half-switching period when modulating the multi-active bridge converter, and s is a non-integer greater than or equal to n.

4. The method according to any one of claims 1 to 3, characterized in that The end moment of the non-zero voltage and current in the k-th parameter update period is earlier than or equal to the start moment of the non-zero voltage and current in the (k + 1)-th parameter update period.

5. The method according to any one of claims 1-3, characterized in that The last pulse signal in the k-th parameter update period and the first pulse signal in the (k + 1)-th parameter update period have opposite polarities, so that the magnetic flux density when modulating the multi-active bridge converter is opposite in the k-th parameter update period and the (k + 1)-th parameter update period.

6. The method according to any one of claims 1-3, characterized in that, The initial parameters include a parameter update trigger threshold, a first coefficient, and a second coefficient; among them, the parameter update trigger threshold is obtained according to the external shift ratio, the duty cycle, the first coefficient, and the second coefficient; the first coefficient is n, and the second coefficient is 2m + 3 or 2s + 3; The obtaining of the target modulation parameters according to the acquired initial parameters includes: When the condition of the parameter update trigger threshold is satisfied, updating the external shift ratio, the duty cycle, the parameter update period, the first coefficient, and the second coefficient in the modulation parameters to obtain the target modulation parameters.

7. The method according to claim 1, characterized in that The preset modulation strategy is a general phase-shift modulation strategy with 2N - 1 scheduling degrees of freedom, and the general phase-shift modulation strategy includes a single phase-shift modulation strategy or an extended soft-switching phase-shift modulation strategy, where N is the number of H bridges in the multi-active bridge converter.

8. A modulation device for a multi-active-bridge converter, characterized in that, Including: A processing module, configured to obtain target modulation parameters according to the acquired initial parameters; Among them, the parameter update period corresponding to the target modulation parameters includes 2n + 3 pulse signals, the pulse signals appear alternately as positive and negative, and n is an integer greater than or equal to 0; the duty cycles of the first pulse signal and the last pulse signal among the 2n + 3 pulse signals are both half of the duty cycle in the initial parameters, and the duty cycles of the other pulse signals are all equal to the duty cycle in the initial parameters; the external shift ratio of any one of the 2n + 3 pulse signals is equal to the external shift ratio in the initial parameters; A modulation module, configured to modulate a multi-active-bridge converter according to the target modulation parameters by using a preset modulation strategy.

9. An electronic device, comprising: A processor and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, Computer-executable instructions are stored in the computer-readable storage medium, and when the computer-executable instructions are executed by a processor, they are used to implement the method according to any one of claims 1-7.

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