Modulation method, device and electronic equipment for multi-active bridge converter

Abstract

The present application provides a modulation method, device and electronic device for a multi-active bridge converter, the method comprising: obtaining target modulation parameters based on acquired initial parameters; wherein the parameter update period corresponding to the target modulation parameters includes 2n+3 pulse signals, the pulse signals alternately appearing positive and negative, and n is an integer greater than or equal to 0; the duty cycle of the first pulse signal and the last pulse signal in 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 pulse signal in the 2n+3 pulse signals is equal to the external shift ratio in the initial parameters. According to the target modulation parameters, the converter is modulated using a pre-set modulation strategy. In this way, within a single parameter update period, there is no quasi-stable DC bias in the winding current and the excitation current of the multi-active bridge transformer.

Description

Technical Field

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

[0002] Multi-Active Bridge (MAB) converters feature multiple interconnected DC ports, flexible and controllable power flow, and high dynamic response. During operation, MAB converters must be modulated to ensure they operate according to specific parameters.

[0003] Currently, the Generic Phase Shift (GPS) modulation method is commonly used to modulate MAB converters. GPS modulation includes Single Phase Shift (SPS) modulation and Extended Soft Switching Phase Shift (ESSPS) modulation.

[0004] However, both of the above modulation modes have transient steady-state DC bias, which makes the transient performance of the MAB converter relatively low. Summary of the Invention

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

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

[0007] According to the obtained initial parameters, the target modulation parameters are obtained;

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

[0009] According to the target modulation parameters, the multi-active bridge converter is modulated using a preset modulation strategy.

[0010] In a possible implementation manner, the duration of the parameter update period is 2m+3 times of a 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 of a 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 time of the non-zero voltage and current in the kth parameter update period is earlier than or equal to the start time of the non-zero voltage and current in the (k+1)th parameter update period.

[0013] In one possible embodiment, the last pulse signal in the kth parameter update period and the first pulse signal in the k+1th parameter update period are of opposite polarity, so that the magnetic flux density when modulating the multi-active bridge converter is opposite in the kth parameter update period and the k+1th parameter update period.

[0014] In a possible implementation, 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 based on the outward 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 target modulation parameters according to the acquired initial parameters includes:

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

[0017] In one possible implementation, the pre-set modulation strategy is a general phase-shift modulation strategy with 2N-1 scheduling degrees of freedom, the general phase-shift modulation strategy includes a single phase-shift modulation strategy or an extended soft-switching phase-shift modulation strategy, and 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, comprising:

[0019] A processing module, configured to obtain target modulation parameters based on the acquired initial parameters;

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

[0021] The modulation module is used to modulate the multi-active bridge converter using a preset modulation strategy according to the target modulation parameters.

[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 implementations 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. When the computer-executable instructions are executed by a processor, they are used to implement the first aspect above and / or various possible implementation methods of the first aspect.

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

[0027] The present application provides a modulation method, device and electronic device for a multi-active bridge converter, the method comprising: obtaining a target modulation parameter based on an acquired initial parameter; wherein the parameter update period corresponding to the target modulation parameter includes 2n+3 pulse signals, the pulse signals alternately appearing positive and negative, and n being an integer greater than or equal to 0; the duty cycle of the first pulse signal and the last pulse signal in the 2n+3 pulse signals are both half of the duty cycle in the initial parameter, and the duty cycles of the other pulse signals are all equal to the duty cycle in the initial parameter; the external shift ratio of any pulse signal in the 2n+3 pulse signals is equal to the external shift ratio in the initial parameter. According to the target modulation parameter, the converter is modulated using a pre-set modulation strategy. In this way, within a single parameter update period, there is no quasi-stable DC bias in the winding current and the excitation current of the multi-active bridge transformer. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0029] Figure 1 A schematic diagram of an H-bridge high-frequency voltage during GPS modulation of a MAB converter provided in an embodiment of the present application;

[0030] Figure 2 A schematic flow chart of a modulation method for a multi-active bridge converter provided in this application;

[0031] Figure 3 A schematic diagram of an H-bridge high-frequency voltage during EH-GPS modulation of a MAB converter provided in an embodiment of the present application;

[0032] Figure 4 A schematic diagram of the H-bridge high-frequency voltage during EH-GPS modulation of another MAB converter provided in an embodiment of the present application;

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

[0034] Figure 6 A schematic diagram of an H-bridge high-frequency voltage during EH-GPS modulation of another MAB converter provided in an embodiment of the present application;

[0035] FIG7 (a) is a schematic diagram of a GPS-modulated winding voltage provided in an embodiment of the present application;

[0036] FIG7( b ) is a schematic diagram of a GPS-modulated winding current provided by an embodiment of the present application;

[0037] FIG7( c ) is a schematic diagram of a GPS-modulated excitation current provided in an embodiment of the present application;

[0038] FIG7( d ) is a schematic diagram of a GPS-modulated hysteresis loop provided in an embodiment of the present application;

[0039] FIG8( a ) is a schematic diagram of an EH-GPS modulated winding voltage provided in an embodiment of the present application;

[0040] FIG8( b ) is a schematic diagram of an EH-GPS modulated winding current provided in an embodiment of the present application;

[0041] FIG8 (c) is a schematic diagram of an EH-GPS modulated excitation current provided in an embodiment of the present application;

[0042] FIG8( d ) is a schematic diagram of a hysteresis loop modulated by EH-GPS provided in an embodiment of the present application;

[0043] Figure 9 A schematic diagram of a specific implementation of EH-GPS modulation provided in an embodiment of the present application;

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

[0045] Figure 11 A timing diagram of a carrier division module provided in an embodiment of the present application;

[0046] Figure 12 A timing diagram of a component carrier and parameter calculation module 1 and a component carrier and parameter calculation module 2 provided in an embodiment of the present application;

[0047] Figure 13 A timing diagram of a gate signal generating module provided in an embodiment of the present application;

[0048] Figure 14 A GPS modulation outward shift comparison provided in the embodiment of the present application Schematic diagram of the time domain waveform during update;

[0049] Figure 15 The embodiment of the present application provides an EH-GPS modulation outward shift comparison Schematic diagram of the time domain waveform during update;

[0050] Figure 16 The embodiment of the present application provides an EH-GPS modulation outward shift comparison Schematic diagram of the hysteresis loop during update;

[0051] Figure 17 A duty cycle under GPS modulation provided in the embodiment of the present application Schematic diagram of the time domain waveform during update;

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

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

[0054] Figure 20 A schematic diagram of a time domain waveform when the number n of full-duty cycle switching cycles inserted under EH-GPS modulation is updated according to an embodiment of the present application;

[0055] Figure 21A schematic diagram of a hysteresis loop when the number n of full-duty cycle switching cycles inserted under EH-GPS modulation is updated according to an embodiment of the present application;

[0056] Figure 22 A schematic diagram of a time domain waveform when the parameter update cycle coefficient R is updated under EH-GPS modulation provided in an embodiment of the present application;

[0057] Figure 23 A schematic diagram of a hysteresis loop when updating the parameter update period coefficient R under EH-GPS modulation provided in an embodiment of the present application;

[0058] Figure 24 A schematic diagram of a time domain waveform when the number n of full duty cycle switching cycles inserted under EH-GPS modulation and the parameter update period coefficient R are updated simultaneously according to an embodiment of the present application;

[0059] Figure 25 A schematic diagram of a hysteresis loop when the number n of full-duty cycle switching cycles inserted under EH-GPS modulation and the parameter update cycle coefficient R are updated simultaneously provided in an embodiment of the present application;

[0060] Figure 26 The actual switching frequency under EH-GPS modulation provided in the embodiment of the present application is Schematic diagram of the time domain waveform during update;

[0061] Figure 27 The actual switching frequency under EH-GPS modulation provided in the embodiment of the present application is Schematic diagram of the hysteresis loop during update;

[0062] Figure 28 Another actual switching frequency under EH-GPS modulation provided in the embodiment of the present application Schematic diagram of the time domain waveform during update;

[0063] Figure 29 Another actual switching frequency under EH-GPS modulation provided in the embodiment of the present application Schematic diagram of the hysteresis loop during update;

[0064] Figure 30 A schematic diagram of a time domain waveform when EH-GPS modulation switches to GPS modulation provided in an embodiment of the present application;

[0065] Figure 31 A schematic diagram of a hysteresis loop when EH-GPS modulation switches to GPS modulation provided in an embodiment of the present application;

[0066] Figure 32 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0067] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0068] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0069] The MAB converter is an isolated multi-port DC-DC converter with 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. For a port number N ≥ 2, N = 2 is a Dual Active Bridge (DAB) converter; N = 3 is a Triple Active Bridge (TAB) converter; N = 4 is a Quadruple Active Bridge (QAB) converter, and so on.

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

[0072] All the following voltage, current and inductance parameters are calculated based on the number of transformer turns.

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

[0074] The function of the jth (j=1,…,N) H-bridge is: 、 、 、 Under the modulation of ) is converted to duty cycle ( )Adjustable high frequency square wave ( The high-frequency square wave voltages output by N H-bridges are simultaneously applied to the N windings of the transformer. Through the phase difference between each high-frequency square wave voltage ( ) controls the AC current ( ), and then control the power flow between each H-bridge, thereby realizing the control of the power transfer of the MAB converter.

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

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

[0077] Assume that the DC voltage of H bridge j is , the DC voltage of H bridge i is When GPS is modulated, the high-frequency square wave output by H bridge j is ,frequency , half switching cycle duty cycle , compared with outward migration ; The high-frequency square wave output by H-bridge i is ,frequency , half switching cycle duty cycle , compared with outward migration At this time, the difference in the outward displacement between H bridge j and H bridge i is ,and , see Figure 1 shown. Figure 1 This is a schematic diagram of the H-bridge high-frequency voltage during GPS modulation of a MAB converter provided in an embodiment of the present application.

[0078] Therefore, when GPS is modulated The degrees of freedom are 、 、…、 ; Assume that the H bridge with the most advanced phase is , then the range of the outward shift is limited to …、 .

[0079] During GPS modulation, the power transmitted from H-bridge j to H-bridge i is:

[0080] ;

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

[0082] Table 1

[0083]

[0084] Since the DC bias-free definition of a MAB converter is usually defined as: the winding AC current has no bias, that is, no DC component, in steady state. In the π-shaped equivalent circuit model of a multi-winding transformer considering the magnetizing inductance, the AC current at the port should not have a DC component in steady state. This requires that the following two specific requirements be met simultaneously: First, The current on the transformer should not have a DC component in steady state; secondly, considering the excitation state of the transformer core, The current on the MOSFET should not have a DC component in steady state.

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

[0086] (1) Even if the input parameters are constant, the excitation current still has a transient bias, and the time constant is large and the transient time is long, which causes the transformer bias and AC and DC currents to increase, the transient performance of the MAB converter to decrease, and the loss to increase.

[0087] (2) The temporal overlap of AC voltage and current in adjacent switching cycles is inevitable. Therefore, when the operating state and modulation parameters change, especially when the external phase shift ratio changes, abnormal pulse voltage will be generated, resulting in uncontrollable power transfer. At the same time, due to the change in modulation parameters, the time integral of the square wave voltage becomes asymmetric, and the winding current produces a significant transient bias, which reduces the transient performance of the MAB converter and increases the loss.

[0088] Therefore, the commonly used GPS modulation method has a transient steady-state DC bias, which makes the transient performance of the MAB converter low.

[0089] In some implementations, based on SPS or ESSPS modulation, a zero voltage state of fixed or variable duration is added between the turn-off time of the lower and upper switches of each H-bridge in the previous switching cycle and the turn-on time of the upper and lower switches in the current cycle. This improves the dynamic response speed of the modulation method and eliminates starting transient overcurrent in the windings.

[0090] However, the circuit model of this modulation method does not take into account the transient steady-state bias of the excitation current and the core flux density.

[0091] In other implementations, based on ESSPS modulation, different duty cycles are set for the first and second halves of the switching cycle; different external phase shifts are set for the first and second halves of the switching cycle; and phase-shifted zero-voltage sequences with varying durations are added at the end of the first and second halves of the switching cycle. These direct modulation parameters are calculated from key input parameters (external phase shift, duty cycle, global frequency reduction factor, and DC voltage sampling) according to current bias and flux density bias principles. This modulation method eliminates transient winding current and magnetic bias when the input modulation parameters change, resulting in minimal power transfer delay and high accuracy.

[0092] However, this modulation method still has some problems: (1) Based on ESSPS modulation, the duty cycle parameter is calculated from the DC voltage detection value, and is therefore greatly affected by the dynamic response, error, and noise of the DC voltage sampling; (2) The duty cycle parameters of each port cannot be flexibly controlled 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) The operating conditions where the switching frequency may change are not taken into account.

[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 of each parameter update cycle are set unchanged, and each parameter update cycle contains pulses of an odd number of half-switching cycles greater than or equal to 3. The duty cycle of each port in the first and last half-switching cycles is half the duty cycle of the other half-switching cycles, and the external shift ratio of each port in all half-switching cycles is equal to the input external shift ratio. In this way, within a parameter switching cycle, the AC voltage is axially symmetric about the midpoint of the parameter switching cycle, and the sub-circuit current between ports j and i of the MAB transformer and the independent excitation inductor current are centrally symmetric about the midpoint of the parameter switching cycle. Therefore, the modulation method of the present application can ensure that neither the winding current nor the excitation current of the MAB transformer has any transient DC bias.

[0094] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments 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 in conjunction with the accompanying drawings.

[0095] It should be noted that the modulation method of the multi-active bridge converter provided in the embodiment of the present application is 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 This is a flow chart of a modulation method for a multi-active bridge converter provided by this application. Figure 2 As 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 parameter includes 2n+3 pulse signals, the pulse signals are alternating between positive and negative, and n is an integer greater than or equal to 0; the duty cycle of the first pulse signal and the last pulse signal in 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 equal to the duty cycle in the initial parameters; the outward shift ratio of any pulse signal in the 2n+3 pulse signals is equal to the outward shift ratio in the initial parameters.

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

[0100] S202 : Modulate the converter using a preset modulation strategy according to target modulation parameters.

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

[0102] like Figure 3 As shown, the outward shift is ,in ; Duty cycle ;Actual switching frequency .

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

[0104] In the embodiment of the present application, the parameter update period length is not necessarily equal to an integer multiple of the half switching period length. 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 of a 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 cycles included in the parameter update cycle is an integer, for example, Figure 3 As shown, the parameter update cycle includes 2n+3 half switching cycles.

[0107] In another possible implementation, the duration of the parameter update period is 2s+3 times of a 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 Schematic diagram of the H-bridge high-frequency voltage during EH-GPS modulation of another MAB converter provided in an embodiment of the present application.

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

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

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

[0112] exist Figure 5 In the example, the output voltage timing of the kth parameter update cycle of the jth port is shown in Table 2 below.

[0113] Table 2

[0114]

[0115] In order to improve power transfer efficiency, the length of the parameter update cycle 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 cycle.

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

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

[0118] In addition, the first The current end point of the parameter update cycle is the end time of interval [4n+6], and the The current starting points of the parameter update cycles, i.e., the starting time of interval [2], must not overlap. In other words, when the length of interval [4n+7] is a negative number, the minimum length of interval [1] must be greater than or equal to the maximum value of the opposite length of interval [4n+7]. That is, the minimum length of interval [1] must be greater than or equal to the maximum value of the opposite length of interval [4n+7], and the following formula (1) must be satisfied.

[0119] (1)

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

[0121] (2)

[0122] When the preset modulation strategy is GPS modulation with arbitrary outward shift ratio and duty cycle, the right side of the inequality in the constraint condition in equation (2) must be less than or equal to n+1.5. In other words, R ≥ n+1.5.

[0123] based on Figure 5 As can be seen from Table 2, intervals [2] and [4n+6], intervals [3] and [4n+5], and interval [4] together form a time-domain symmetrical voltage waveform, and the positive voltage integrals of intervals [2] and [4n+6], intervals [3] and [4n+5] are all half of the negative voltage integral of interval [4]. Therefore, the AC voltages of the five intervals [2], [3], [4], [4n+5], and [4n+6] are It is axisymmetric relative to the midpoint of interval [4]; the voltage source Individually stimulated ports and Current between sub-circuits , and the independent magnetizing inductor current It starts from 0, first rises, then falls, then rises, and finally returns to 0, showing central symmetry with respect to the midpoint of interval [4]. In other words, the voltage or current within a parameter update cycle is integrated, and the integral result is 0. Therefore, in the modulation method provided in the embodiment 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 kth parameter update cycle and the first pulse signal in the k+1th parameter update cycle are of opposite polarity, so that the magnetic flux density when modulating the multi-active bridge converter is opposite in the kth parameter update cycle and the k+1th parameter update cycle.

[0125] by Figure 3 For example, Figure 6 This is a schematic diagram of the H-bridge high-frequency voltage during EH-GPS modulation of another MAB converter provided in an embodiment of the present application.

[0126] Hysteresis loss power of multi-winding high-frequency transformer core in MAB converter , where the hysteresis frequency is the number of closures of the hysteresis loop within 1 second, and the hysteresis loss energy It is proportional to the area enclosed each time the small hysteresis loop is closed or the large hysteresis loop is closed.

[0127] When the current GPS modulation method modulates a MAB transformer, the winding voltage is shown in Figure 7(a), the winding current is shown in Figure 7(b), the excitation current is shown in Figure 7(c), and the hysteresis loop is shown in Figure 7(d). Figure 7(a) is a schematic diagram of a GPS-modulated winding voltage according to an embodiment of the present application. Figure 7(b) is a schematic diagram of a GPS-modulated winding current according to an embodiment of the present application. Figure 7(c) is a schematic diagram of a GPS-modulated excitation current according to an embodiment of the present application. Figure 7(d) is a schematic diagram of a GPS-modulated hysteresis loop according to an embodiment of the present application.

[0128] As shown in Figure (d), the BH hysteresis loop of the MAB transformer closes at the large loop in each actual switching cycle, and the hysteresis loss energy ,in is the hysteresis loss energy corresponding to the large loop area.

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

[0130] exist Figure 6Based on the H-bridge high-frequency voltage shown, the EH-GPS modulation method provided by this application modulates the MAB transformer. The winding voltage is shown in Figure 8(a), the winding current is shown in Figure 8(b), the excitation current is shown in Figure 8(c), and the hysteresis loop is shown in Figure 8(d). Figure 8(a) is a schematic diagram of the winding voltage modulated by EH-GPS according to an embodiment of this application. Figure 8(b) is a schematic diagram of the winding current modulated by EH-GPS according to an embodiment of this application. Figure 8(c) is a schematic diagram of the excitation current modulated by EH-GPS according to an embodiment of this application. Figure 8(d) is a schematic diagram of the hysteresis loop modulated by EH-GPS according to an embodiment of this application.

[0131] As shown in Figure 8 (a) and Figure 8 (b), when EH-GPS is modulated, when the last pulse signal in the kth parameter update cycle is opposite to the polarity of the first pulse signal in the k+1th parameter update cycle, the The non-zero voltage and current of the first parameter update cycle are The non-zero voltage and current of the parameter update cycle are opposite, and the magnetic flux density during EH-GPS modulation The waveforms are opposite in the two parameter update cycles.

[0132] The BH hysteresis loop of the MAB transformer is closed twice at the small loop and closed once at the large loop in every two parameter update cycles. Second, hysteresis loss Lower than GPS modulation loss .

[0133] Hysteresis loss As shown in formula (3):

[0134] (3)

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

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

[0137] (4)

[0138] For example, ,but 、 When the actual switching frequency, DC voltage, external shift phase ratio and duty cycle are the same, the hysteresis loss of EH-GPS modulation is about 59% of that of GPS modulation.

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

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

[0141] In combination with the above embodiment, the parameter update trigger threshold is , the first coefficient is n, and the second coefficient is 2m+3 or 2s+3.

[0142] The parameter update trigger threshold is obtained based on the shift ratio, the duty cycle, the first coefficient, and the second coefficient.

[0143] like Figure 5 As shown in formula (1), due to ,and , then when all ports are in the interval [1] and not in the interval [4n+6], all winding currents are 0, and the parameters can be updated at this time. The time range at this time ( )for:

[0144] (5)

[0145] in, Parameter update trigger threshold. In step S401 described in the above embodiment, when the target modulation parameters are obtained based on the acquired initial parameters, the shift ratio, duty cycle, parameter update period, first coefficient, and second coefficient in the modulation parameters can be updated when the parameter update trigger threshold is met to obtain the target modulation parameters.

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

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

[0148] When n=0 and R=1.5, the corresponding transmission power of each phase shift condition area can be seen in Table 3.

[0149] Table 3

[0150] (H bridge →H-bridge )

[0151]

[0152]

[0153]

[0154] In an embodiment of the present application, the pre-set modulation strategy is a general phase-shift modulation strategy with 2N-1 scheduling degrees of freedom. 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.

[0155] When the preset modulation strategy is ESSPS modulation, the combination becomes EH-ESSPS modulation.

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

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

[0158] (2) The beginning and end of the parameter update cycle are approximately the turn-on and turn-off of the zero current switch (ZCS), which further reduces the switching loss.

[0159] (3) Transformer magnetic flux density , winding voltage , winding current The fundamental frequency is , no even harmonics; the maximum harmonic component is located at .

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

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

[0162] The EH-GPS modulation method of the present application is described below through a feasible implementation method.

[0163] Figure 9 This is a schematic diagram of a specific implementation of EH-GPS modulation provided in an embodiment of the present application.

[0164] It should be noted that, in specific applications, the specific implementation of EH-GPS modulation can be achieved by using a microcontroller such as a single chip microcomputer or a field programmable gate array (FPGA). Figure 9 Each module in the embodiment can be a hardware module or a software module, and the embodiment of the present application does not limit the specific implementation equipment.

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

[0166] The external input signal modulated by EH-GPS, that is, the initial parameters of the above embodiment are: switching frequency input value , outward shift compared to input value , duty cycle input value , insert the full duty cycle switching cycle number input value , parameter update cycle coefficient input value , and the main parameter update trigger threshold , whose value range is shown in the above formula (5). The target modulation parameter of EH-GPS modulation is Figure 9 The output signal shown is the gate drive signal 、 、 、 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, so the frequency update module and the main parameter update module need to store the initial values ​​of their output values ​​respectively.

[0168] The following describes the role of each module in EH-GPS modulation.

[0169] 1. Main carrier generation and synchronization module

[0170] Figure 10 A timing diagram of a main carrier generation and synchronization module provided in an embodiment of the present application.

[0171] like Figure 10 As shown, the main carrier signal CR has a time slope Rising, with an upper limit ; Carrier selection signal SEL 12 The rising edge of the frequency update trigger signal TRF is generated at the moment when CR returns to zero each time; the rising edge of the main parameter update trigger signal TRR is generated at the rising stage of the CR signal and Moment of crossover.

[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 actual switching frequency is stored in the frequency update module. When the frequency update trigger signal TRF rises, the output Update to input value .

[0174] 3. Main parameter update module

[0175] The main parameter update module is used to store and update the external comparison , duty cycle , the number of full duty cycle switching cycles inserted , parameter update cycle coefficient Before the system starts running, the frequency update module has stored the initial values ​​of the above parameters. When the main parameter update trigger signal TRR rises, the output 、 、 、 Update to input values ​​respectively 、 、 、 .

[0176] 4. Carrier sub-module

[0177] Figure 11 A timing diagram of a carrier division module provided in an embodiment of the present application.

[0178] like Figure 11 As shown, according to the main carrier signal CR input and the sub-carrier selection signal SEL 12 , the sub-carrier signals CR1 and CR2 are respectively reset to zero and SEL12 It starts at 0 and 1, and has an upper limit ; After reaching the upper limit, it returns to zero. Therefore, CR1 and CR2 are There is a temporal overlap in this case.

[0179] 5. Carrier and gate signal module

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

[0181] Figure 12 A timing diagram of a component carrier and parameter calculation module 1 and a component carrier and parameter calculation module 2 provided in an embodiment of the present application.

[0182] like Figure 12 As shown, in the unit carrier and parameter calculation module 1, the unit carrier signal CR j,1 Phase shift by CR1 The triangular wave signal generated after the upper and lower limits are , the continuous phase is ,Right now Half switching cycles; in the first and last half switching cycles, the positive comparison signal is , the negative comparison signal is ; For the rest of the middle half switching cycles, the positive comparison signal is , the negative comparison signal is ; The rest of the time, 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 Phase shift by CR2 The triangular wave signal generated after the upper and lower limits are , the continuous phase is ,Right now Half switching cycles; in the first and last half switching cycles, the positive comparison signal is , the negative comparison signal is ; For the rest of the middle half switching cycles, the positive comparison signal is , the negative comparison signal is ; The rest of the time, the positive comparison signal is 1 and the negative comparison signal is .

[0184] Figure 13 A timing diagram of a gate signal generating module provided in an embodiment of the present application.

[0185] like Figure 13As shown, when the unit carrier signal CR j,1 Greater than positive comparison signal When the switch signal S j,1 is 1; when the unit carrier signal CR j,1 Less than negative comparison signal When the switch signal S j,1 for ; When the unit carrier signal CR j,2 Greater than positive comparison signal When the switch signal S j,2 is 1; when the unit carrier signal CR j,2 Less than negative positive comparison signal When the switch signal S j,2 for .

[0186] Switching signal S j,1 and S j,2 Combination, output gate drive signal 、 、 、 , and generate the required winding voltage .

[0187] In combination with the above embodiments, the EH-GPS modulation method of the present application and its implementation effects are described below by taking the MAB converter as a quad active bridge (QAB) converter as an example.

[0188] The physical parameters of the QAB converter are: the number of transformer turns can be reduced to 1; 、 、 、 ; Series leakage inductance of each winding ; Transformer's T-shaped magnetizing inductance , using the Preisach hysteresis model (core parameters: coercivity ,remanence , saturation magnetic field strength , saturation magnetic flux density , saturation relative permeability ).

[0189] Next, the parameter update and dynamic response of the EH-GPS modulation method are described.

[0190] Compared with the update outward For example, compared with external Updates can include:

[0191] Among them, the operating parameters include: actual switching frequency ; Duty cycle 、 、 、 ; Compared with outward migration 、 、 ; Number of full duty cycle switching cycles inserted , parameter update cycle coefficient . The newer changes compared to the outbound migration are Updated to .

[0192] Figure 14 A GPS modulation outward shift comparison provided in the embodiment of the present application Schematic diagram of the time domain waveform during update.

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

[0194] Figure 15 The embodiment of the present application provides an EH-GPS modulation outward shift comparison Schematic diagram of the time domain waveform during update.

[0195] Figure 16 The embodiment of the present application provides an EH-GPS modulation outward shift comparison Schematic diagram of the hysteresis loop during updating.

[0196] like Figure 15 and Figure 16 As shown, when EH-GPS is modulated, the outward shift is compared with the input value When the steps change, the outward movement is compared with Updated and executed at the rising edge of TRR, the winding current and the excitation current have no transient steady-state bias, and the transformer and inductor have no magnetic bias; the delay in completing the modulation execution and outputting the required power is less than .

[0197] To update the duty cycle For example, the duty cycle Updates can include:

[0198] Among them, the operating parameters include: actual switching frequency ; Duty cycle 、 、 ; Compared with outward migration 、 、 、 ; Number of full duty cycle switching cycles inserted , parameter update cycle coefficient The duty cycle is determined by Updated to .

[0199] Figure 17 A duty cycle under GPS modulation provided in the embodiment of the present application Schematic diagram of the time domain waveform during update.

[0200] like Figure 17 As shown in the figure, during GPS modulation, a sudden change in duty cycle will cause a large transient steady-state bias in the winding current and the excitation current.

[0201] Figure 18 A duty cycle under EH-GPS modulation provided in the embodiment of the present application Schematic diagram of the time domain waveform during update.

[0202] Figure 19 A duty cycle under EH-GPS modulation provided in the embodiment of the present application Schematic diagram of the hysteresis loop during updating.

[0203] like Figure 18 and Figure 19 As shown, when EH-GPS is modulated, the duty cycle input value When the step changes, the duty cycle Updated and executed at the rising edge of TRR, the winding current and the excitation current have no transient steady-state bias, and the transformer and inductor have no magnetic bias; the delay in completing the modulation execution and outputting the required power is less than .

[0204] The update of the number n of inserted full duty cycle switching cycles may include:

[0205] Operating parameters can include: actual switching frequency ; Duty cycle 、 、 、 ; Compared with outward migration 、 、 、 ;Parameter update cycle coefficient The number of full duty cycle switching cycles inserted is given by Updated to .

[0206] Figure 20 A schematic diagram of a time domain waveform when the number n of full-duty cycle switching cycles inserted under EH-GPS modulation is updated according to an embodiment of the present application.

[0207] Figure 21 A schematic diagram of a hysteresis loop when the number n of full-duty switching cycles inserted under EH-GPS modulation is updated according to an embodiment of the present application.

[0208] like Figure 20 and Figure 21 As shown, when EH-GPS is modulated, the input value of the number of full duty cycle switching cycles inserted is When the step changes, the number of full duty cycle switching cycles inserted Updated and executed at the rising edge of TRR, the winding current and the excitation current have no transient steady-state bias, and the transformer and inductor have no magnetic bias; the delay in completing the modulation execution and outputting the required power is less than .

[0209] When updating the parameter update period coefficient R, the following steps may be performed:

[0210] Operating parameters can include: actual switching frequency ; Duty cycle 、 、 、 ; Compared with outward migration 、 、 、 ; Number of full duty cycle switching cycles inserted The parameter update cycle coefficient is given by Updated to .

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

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

[0213] like Figure 22 and Figure 23 As shown, when EH-GPS is modulated, the parameter update cycle coefficient input value When the step changes, the parameter update cycle coefficient Updated and executed at the rising edge of TRR, the winding current and the excitation current have no transient steady-state bias, and the transformer and inductor have no magnetic bias; the delay in completing the modulation execution and outputting the required power is less than .

[0214] When the number of inserted full duty cycle switching cycles n and the parameter update period coefficient R are updated simultaneously, the following steps may be included:

[0215] Operating parameters can include: actual switching frequency ; Duty cycle 、 、 、 ; Compared with outward migration 、 、 、 The number of full duty cycle switching cycles inserted is given by Updated to ; At the same time, the parameter update cycle coefficient is determined by Updated to .

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

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

[0218] like Figure 24 and Figure 25 As shown, when EH-GPS is modulated, the input value of the number of full duty cycle switching cycles inserted is and parameter update cycle coefficient input value At the same time, when the step changes, the number of full duty cycle switching cycles inserted and parameter update cycle coefficient Updated and executed at the rising edge of TRR, the winding current and the excitation current have no transient steady-state bias, and the transformer and inductor have no magnetic bias; the delay in completing the modulation execution and outputting the required power is less than .

[0219] The actual switching frequency When updating, there are two possible implementations:

[0220] In one possible implementation, When the operating parameters can include: duty cycle 、 、 、 ; Compared with outward migration 、 、 、 ; Number of full duty cycle switching cycles inserted , parameter update cycle coefficient The actual switching frequency is determined by Updated to .

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

[0222] Figure 27 The actual switching frequency under EH-GPS modulation provided in the embodiment of the present application is Schematic diagram of the hysteresis loop during updating.

[0223] like Figure 26 and Figure 27 As shown, EH-GPS modulation and When the actual switching frequency input value When the step changes, the actual switching frequency Update and execute at the rising edge of TRF, the winding current and the excitation current have no transient steady-state bias, and the transformer and inductor have no magnetic bias; the delay to complete the modulation execution and output the required power is less than .

[0224] In another possible implementation, When the operating parameters can include: duty cycle 、 、 、 ; Compared with outward migration 、 、 、 ; Number of full duty cycle switching cycles inserted , parameter update cycle coefficient The actual switching frequency is determined by Updated to .

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

[0226] Figure 29 Another actual switching frequency under EH-GPS modulation provided in the embodiment of the present application Schematic diagram of the hysteresis loop during updating.

[0227] like Figure 28 and Figure 29 As shown, EH-GPS modulation and When the actual switching frequency input value When the step transformation is performed, the parameter is first updated to the period coefficient Updated to when TRR rises The actual switching frequency Update and execute at the rising edge of TRF, the winding current and the excitation current have no transient steady-state bias, and the transformer and inductor have no magnetic bias; the delay to complete the modulation execution and output the required power is less than .

[0228] Next, the hysteresis loss in the actual operation of EH-GPS modulation is explained.

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

[0230] One possible situation is when the same and When the operating parameters can include: actual switching frequency , compared with outward migration 、 、 、 , duty cycle 、 、 、 , the number of full duty cycle switching cycles inserted , parameter update cycle coefficient .

[0231] When the same and The comparison of hysteresis loss between EH-GPS modulation and GPS modulation in actual operation is shown in Table 5.

[0232] Table 5

[0233]

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

[0235] In another possible case, when the actual switching frequency and the delivered power are the same, the operating parameters may include: the actual switching frequency ; Duty cycle 、 、 、 ;GPS modulation: outward shift compared to 、 、 、 ; EH-GPS modulation: outward shift compared to 、 、 、 ; Number of full duty cycle switching cycles inserted , parameter update cycle coefficient .

[0236] When the actual switching frequency and the transferred power are the same, the comparison of the hysteresis loss of the actual operation of 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 transfer power are the same, that is, when the transfer power of EH-GPS modulation is equal to that of GPS modulation, the hysteresis loss of EH-GPS modulation is still approximately 57.5% of that of GPS modulation because the switching frequency and port voltage amplitude remain approximately unchanged.

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

[0241] Next, the case where the EH-GPS modulation is switched to the GPS modulation will be described.

[0242] When EH-GPS modulation switches to GPS modulation, it can include:

[0243] Operating parameters can include: actual switching frequency ; Duty cycle 、 、 、 ; Compared with outward migration 、 、 、 ; Number of full duty cycle switching cycles inserted , parameter update cycle coefficient .

[0244] Figure 30 A schematic diagram of a time domain waveform when EH-GPS modulation switches to GPS modulation provided in an embodiment of the present application.

[0245] Figure 31 A schematic diagram of a hysteresis loop when EH-GPS modulation switches to GPS modulation provided in an embodiment of the present application.

[0246] like Figure 30 and Figure 31 As shown, during the parameter update cycle The phase can be flexibly switched to GPS modulation with the same switching frequency, duty cycle, and external shift ratio. The winding current and excitation current have no transient steady-state bias, and the transformer and inductor have no magnetic bias.

[0247] Figure 32This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application. Figure 32 As shown, the electronic device 370 provided in this embodiment includes: at least one processor 3701 and a memory 3702. Optionally, the device 370 also includes a communication component 3703. The processor 3701, the memory 3702, and the communication component 3703 are connected via a bus 3704.

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

[0249] The specific implementation process of processor 3701 can be found in the above-mentioned method embodiment. Its implementation principle and technical effects are similar, and will not be repeated here in this embodiment.

[0250] In the above embodiments, it should be understood that the processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASICs), etc. A general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in the present invention may be directly executed by a hardware processor or by a combination of hardware and software modules within the processor.

[0251] The memory may include random access memory (RAM) and may also include non-volatile memory (NVM), such as at least one disk storage.

[0252] A bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus. Buses can be categorized as address buses, data buses, and control buses. For ease of illustration, the buses in the drawings of this application are not limited to just one bus or just 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, in which computer-executable instructions are stored. When a processor executes the computer-executable instructions, the above method is implemented.

[0255] The readable storage medium may be implemented by any type of volatile or non-volatile memory 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 storage, flash memory, magnetic disk, or optical disk. The readable storage medium may be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0256] An exemplary readable storage medium is coupled to a processor so that the processor can read information from the readable storage medium and write information to the readable storage medium. Of course, the readable storage medium can also be an integral part 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 in the device as discrete components.

[0257] The division of units is merely a logical functional division; actual implementations may employ alternative divisions, such as combining or integrating multiple units or components into another system, or omitting or disabling certain features. Furthermore, any direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between devices or units, either through an interface, electrical, mechanical, or other means.

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

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

[0260] If a function is implemented as 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, or the portion that contributes to the prior art, or a portion of the 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 can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the various embodiments of the method of the present invention. The aforementioned storage medium includes various media that can store program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0261] Those skilled in the art will appreciate that all or part of the steps in the above-described method embodiments can be implemented using hardware associated with program instructions. The aforementioned program can be stored in a computer-readable storage medium. When executed, the program performs the steps of the above-described method embodiments. The aforementioned storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disks, or optical disks.

[0262] Finally, it should be noted that those skilled in the art will readily identify other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The present invention is not limited to the precise structure described above and illustrated in the accompanying drawings, and various modifications and variations may be made without departing from the scope thereof. The scope of the present invention is limited solely by the appended claims.

Claims

1. A modulation method for a multi-active bridge converter, characterized in that: The method comprises: According to the obtained initial parameters, the target modulation parameters are obtained; The parameter update period corresponding to the target modulation parameter includes 2n+3 pulse signals, the pulse signals are positive and negative alternately, and n is an integer greater than or equal to 0; the duty cycle of the first pulse signal and the last pulse signal in the 2n+3 pulse signals are both half of the duty cycle in the initial parameter, and the duty cycles of the other pulse signals are equal to the duty cycle in the initial parameter; the outward shift ratio of any pulse signal in the 2n+3 pulse signals is equal to the outward shift ratio in the initial parameter; According to the target modulation parameters, the multi-active bridge converter is modulated using a preset modulation strategy.

2. The method according to claim 1, characterized in that The duration of the parameter update period is 2m+3 times of a half switching period when modulating the multi-active bridge converter, where 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 of a half switching period when modulating the multi-active bridge converter, where 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 time of the non-zero voltage and current in the kth parameter update cycle is earlier than or equal to the start time of the non-zero voltage and current in the (k+1)th parameter update cycle.

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

6. The method according to any one of claims 1 to 3, characterized in that The initial parameters include a parameter update trigger threshold, a first coefficient, and a second coefficient; wherein the parameter update trigger threshold is obtained based on the outer 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; m is an integer greater than or equal to n, and s is a non-integer greater than or equal to n; Obtaining target modulation parameters according to the acquired initial parameters includes: When the condition of the parameter update trigger threshold is met, the shift ratio, duty cycle, parameter update period, first coefficient and second coefficient in the modulation parameters are updated 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, wherein the general phase-shift modulation strategy includes a single phase-shift modulation strategy or an extended soft-switching phase-shift modulation strategy, and 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: include: A processing module, configured to obtain target modulation parameters based on the acquired initial parameters; The parameter update period corresponding to the target modulation parameter includes 2n+3 pulse signals, the pulse signals are positive and negative alternately, and n is an integer greater than or equal to 0; the duty cycle of the first pulse signal and the last pulse signal in the 2n+3 pulse signals are both half of the duty cycle in the initial parameter, and the duty cycles of the other pulse signals are equal to the duty cycle in the initial parameter; the outward shift ratio of any pulse signal in the 2n+3 pulse signals is equal to the outward shift ratio in the initial parameter; The modulation module is used to modulate the multi-active bridge converter using a preset modulation strategy according to the target modulation parameters.

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 to 7.

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

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