Current-sharing control method, device, unit and module for multi-phase resonant converter

Abstract

The application provides a current sharing control method, device, unit and module of a multi-phase resonant converter, and relates to the technical field of power electronics. The multi-phase resonant current of a resonant cavity in the multi-phase resonant converter is obtained, at least two angle change coefficients and initial angle change amounts of each phase are determined according to the multi-phase resonant current, target angle change amounts of each phase are determined according to the size relationship of the multi-phase resonant current, the at least two angle change coefficients and the initial angle change amounts of each phase, each phase resonant current of the resonant cavity is controlled by the multi-phase resonant converter according to the target angle change amounts of each phase, the target angle change amounts of each phase are obtained by analyzing the multi-phase resonant current, and then each phase resonant current of the resonant cavity is adjusted according to the target angle change amounts of each phase, so that the multi-phase resonant currents share the current, and the failure rate of the charging module can be reduced.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and more specifically, to a current sharing control method, device, unit, and module for a multiphase resonant converter. Background Technology

[0002] DC charging piles are charging stations for DC electric new energy vehicles. The charging modules within them can employ single-phase resonant converters to achieve zero-voltage switching on both the primary and secondary sides, optimizing current sharing and termination losses between parallel windings and synchronous rectifiers. However, with the rapid development of new energy vehicles, their charging demands have increased, placing higher requirements on the charging power of DC charging piles as essential supporting infrastructure.

[0003] In the current technology, to meet the charging power requirements of different manufacturers' new energy vehicles, various charging pile manufacturers have successively launched charging piles with different power levels. During the gradual upgrading of the charging module in a DC charging pile, the topology of the conversion circuit in the charging module has gradually evolved from the initial single-phase resonant converter to a multi-phase resonant converter. However, in a multi-phase resonant converter, the uneven current distribution among phases due to differences in component parameters during parallel connection can lead to some phases receiving almost no power while others receive a large amount of power, potentially causing charging module malfunctions. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the prior art by providing a current sharing control method, device, unit, and module for a multiphase resonant converter, thereby solving the technical problem of uneven current sharing among phases in the prior art.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows:

[0006] In a first aspect, embodiments of this application provide a current sharing control method for a multiphase resonant converter, the method comprising:

[0007] Obtain the multiphase resonant current in the resonant cavity of a multiphase resonant converter;

[0008] Based on the multiphase resonant current, at least two angle variation coefficients and the initial angle variation of each phase are determined;

[0009] Based on the magnitude relationship of the multiphase resonant currents, the at least two angle variation coefficients, and the initial angle variation of each phase, the target angle variation of each phase is determined.

[0010] Based on the target angle change of each phase, the multiphase resonant converter is controlled to adjust the resonant current of each phase of the resonant cavity.

[0011] Optionally, determining at least two angle variation coefficients and the initial angle variation of each phase based on the multiphase resonant current includes:

[0012] Based on the multiphase resonant current, a first reference current value and at least two second reference current values ​​are determined;

[0013] Calculate the at least two angle change coefficients based on the first reference current value and at least two second reference current values;

[0014] The initial angle change of each phase is determined based on the first reference current value and the multiphase resonant current.

[0015] Optionally, the multiphase resonant current includes: a three-phase resonant current;

[0016] The step of determining the first reference current value and at least two second reference current values ​​based on the multiphase resonant current includes:

[0017] Based on the multiphase resonant current, the maximum resonant current, the minimum resonant current, and the average resonant current are determined; the first reference current value is the maximum resonant current, and the at least two second reference current values ​​include the minimum resonant current and the average resonant current.

[0018] Optionally, calculating the at least two angle change coefficients based on the first reference current value and at least two second reference current values ​​includes:

[0019] Calculate at least two current error parameters based on the first reference current value and the at least two second reference current values;

[0020] Calculate the at least two angle variation coefficients based on the at least two current error parameters.

[0021] Optionally, determining the initial angle change of each phase based on the first reference current value and the multiphase resonant current includes:

[0022] Based on the first reference current value and the multiphase resonant current, the multiphase current error parameters are determined respectively;

[0023] Based on the multiphase current error parameters, the initial angle change of each phase is determined.

[0024] Optionally, determining the target angle change of each phase based on the magnitude relationship of the multiphase resonant currents, the at least two angle change coefficients, and the initial angle change of each phase includes:

[0025] The angle variation coefficient of each phase is determined based on the magnitude relationship of the multiphase resonant currents and the at least two angle variation coefficients.

[0026] Based on the angle change coefficient of each phase and the initial angle change of each phase, the target angle change of each phase is determined respectively.

[0027] Optionally, determining the angle variation coefficient of each phase based on the magnitude relationship of the multiphase resonant currents and the at least two angle variation coefficients includes:

[0028] Based on the magnitude relationship of the multiphase resonant currents, the angle variation coefficient of the target phase corresponding to the maximum resonant current is determined as the preset reference variation coefficient;

[0029] Based on the magnitude relationship of the multiphase resonant currents, the angle variation coefficients of each phase other than the target phase are determined from the at least two angle variation coefficients; wherein, the larger the resonant current of each other phase, the smaller the angle variation coefficient.

[0030] Secondly, embodiments of this application provide a flow sharing control device, comprising:

[0031] The acquisition module is used to acquire the multiphase resonant current of the resonant cavity in the multiphase resonant converter;

[0032] The first determining module is used to determine at least two angle variation coefficients and the initial angle variation of each phase based on the multiphase resonant current.

[0033] The second determining module is used to determine the target angle change of each phase based on the magnitude relationship of the multiphase resonant current, the at least two angle change coefficients, and the initial angle change of each phase.

[0034] The control module is used to control the multiphase resonant converter to adjust the resonant current of each phase of the resonant cavity according to the target angle change of each phase.

[0035] Thirdly, embodiments of this application provide a control unit, including: a storage medium and a processor, wherein the storage medium stores a computer program executable by the processor, and the processor executes the computer program to implement the current sharing control method for a multiphase resonant converter described in the first aspect.

[0036] Fourthly, embodiments of this application provide a power electronic module, including: a sampling unit, a control unit, a drive unit, and a multiphase resonant converter; the control unit is the control unit described in the third aspect above;

[0037] The sampling unit's acquisition end is connected to the resonant cavity in the multiphase resonant converter, and the sampling unit's output end is connected to the control unit. The control unit is also connected to the control end of the multiphase resonant converter through the driving unit.

[0038] Compared with the prior art, this application has the following beneficial effects:

[0039] This application provides a current sharing control method, device, unit, and module for a multiphase resonant converter. By acquiring the multiphase resonant current in the resonant cavity of the multiphase resonant converter, determining at least two angle variation coefficients and the initial angle variation of each phase based on the multiphase resonant current, determining the target angle variation of each phase based on the magnitude relationship of the multiphase resonant current, the at least two angle variation coefficients, and the initial angle variation of each phase, and controlling the multiphase resonant converter to adjust the resonant current of each phase in the resonant cavity based on the target angle variation of each phase, this application analyzes the multiphase resonant current to obtain the target angle variation of each phase, and then adjusts the resonant current of each phase in the resonant cavity based on the target angle variation of each phase, thereby achieving current sharing among the multiphase resonant currents and reducing the failure rate of the charging module. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of the structure of a power electronic module provided in an embodiment of this application;

[0042] Figure 2 A flowchart illustrating a current sharing control method for a multiphase resonant converter provided in an embodiment of this application;

[0043] Figure 3 This is a schematic diagram of a phase angle change provided in an embodiment of this application;

[0044] Figure 4 A flowchart illustrating a method for determining the angle change coefficient and the initial angle change amount provided in an embodiment of this application;

[0045] Figure 5 A flowchart illustrating a method for calculating the angle change coefficient provided in an embodiment of this application;

[0046] Figure 6 A flowchart illustrating a method for determining the initial angle change provided in an embodiment of this application;

[0047] Figure 7 A flowchart illustrating a method for determining the change in target angle provided in an embodiment of this application;

[0048] Figure 8 A flowchart illustrating a method for determining an angle change coefficient provided in an embodiment of this application;

[0049] Figure 9 A flowchart illustrating another current sharing control method for a multiphase resonant converter provided in this application embodiment;

[0050] Figure 10 A schematic diagram illustrating experimental results without employing a flow sharing strategy, as provided in an embodiment of this application;

[0051] Figure 11 A schematic diagram illustrating experimental results using a flow-sharing strategy, provided as an embodiment of this application;

[0052] Figure 12 A schematic diagram of a flow sharing control device provided in an embodiment of this application;

[0053] Figure 13 This is a schematic diagram of a control unit provided in an embodiment of this application. Detailed Implementation

[0054] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. The components of the embodiments of the present application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0055] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0056] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0057] To meet the charging power requirements of different manufacturers' new energy vehicles, the power of the charging modules in charging piles has been gradually upgraded from the initial 7.5kW to 15kW, 20kW, 30kW, 40kW, 60kW, etc. The conversion circuit in the charging module has also been gradually upgraded to a multiphase resonant converter. However, in the process of power increase, the uneven current in each phase of the multiphase resonant converter due to the difference in the parameters of the components during the parallel connection process can easily lead to charging module failure.

[0058] To address the aforementioned issues, this application provides a power electronic module. The following specific examples illustrate the power electronic module provided in this application. Figure 1 This is a schematic diagram of the structure of a power electronic module provided in an embodiment of this application. Figure 1 As shown, the power electronic module includes: a sampling unit 10, a control unit 20, a drive unit 30, and a multiphase resonant converter 40.

[0059] The sampling unit 10 is connected to the resonant cavity in the multiphase resonant converter 40 to sample the multiphase resonant current in the resonant cavity. Specifically, the multiphase resonant current in the resonant cavity can be the multiphase input current of the resonant cavity (the input current of inductors Lr1, Lr2, and Lr3) or the multiphase output current of the resonant cavity (the output current of the three transformers), and no specific limitation is made in this embodiment.

[0060] For example, when the multiphase resonant converter 40 is a three-phase resonant converter, the multiphase resonant currents can be expressed as Ia, Ib, and Ic, where Ia, Ib, and Ic can be the three-phase input currents of the resonant cavity, or they can be the three-phase output currents of the resonant cavity. Figure 1 The terms Ia, Ib, and Ic are explained using the three-phase input current of the resonant cavity as an example.

[0061] In this embodiment of the application, when the multiphase resonant converter 40 is a three-phase resonant converter, such as Figure 1 As shown, its topology can be a multiphase interleaved parallel LLC resonant converter. Each phase in the resonant cavity includes two inductors and one capacitor connected in series. The magnetizing inductor of the two inductors is integrated in the corresponding transformer.

[0062] In this embodiment, the sampling unit 10 can be an Analog-to-Digital converter (AD converter) of a Digital Signal Processing (DSP), which can convert the analog signal corresponding to the multiphase resonant current into a digital signal. Of course, it can also be other current sampling units, and no specific limitation is made in this embodiment.

[0063] The output terminal of the sampling unit 10 is connected to the control unit 20. After the sampling unit 10 acquires the multiphase resonant current, it can transmit the multiphase resonant current to the control unit 20, so that the control unit 20 can perform current sharing control calculation based on the multiphase resonant current. Through the calculation, the new phase angle of each phase can be obtained. That is, the new phase angle of each phase obtained by the current sharing control calculation can realize the current sharing of each phase resonant current.

[0064] Optionally, the sampling unit 10 can also be integrated into the control unit 20. In this case, the control unit 20 is connected to the resonant cavity in the multiphase resonant converter 40 to collect the multiphase resonant current and perform calculations.

[0065] The control unit 20 is also connected to the control terminal of the multiphase resonant converter 40 via the drive unit 30. Specifically, after the control unit 20 calculates the new phase angle of each phase, it can send the new phase angle of each phase to the drive unit 30, so that the drive unit 30 outputs the PWM (Pulse Width Modulation) drive waveform corresponding to the new phase angle of each phase to the control terminal of each power switch in the inverter circuit of the multiphase resonant converter 40, thereby enabling the resonant current of each phase in the resonant cavity to be shared.

[0066] Optionally, the control unit 20 can be a microcontroller unit (MCU), or other units or devices with computing, processing and control functions. No specific limitations are imposed in the embodiments of this application.

[0067] This application provides a power electronic module, including: a sampling unit, a control unit, a drive unit, and a multiphase resonant converter. The sampling unit's acquisition terminal is connected to the resonant cavity in the multiphase resonant converter, and the sampling unit's output terminal is connected to the control unit. The control unit is also connected to the control terminal of the multiphase resonant converter through the drive unit. The control unit can acquire the multiphase resonant current in the resonant cavity of the multiphase resonant converter acquired by the sampling unit, calculate the new phase angle of each phase, and then control each power switch in the inverter circuit of the multiphase resonant converter through the drive unit according to the new phase angle of each phase, thereby achieving the current sharing effect of each phase resonant current in the resonant cavity.

[0068] In the above Figure 1 Based on an embodiment of a power electronic module shown, in order to achieve the current sharing effect of multiphase resonant current, this application provides a current sharing control method for a multiphase resonant converter. The following specific examples will explain the current sharing control method for a multiphase resonant converter provided by this application. Figure 2 A flowchart illustrating a current sharing control method for a multiphase resonant converter provided in this application embodiment is shown below. Figure 2As shown, this method is applied to the control unit in the aforementioned power electronic module, and the method includes:

[0069] S201, obtain the multiphase resonant current of the resonant cavity in the multiphase resonant converter.

[0070] Specifically, the multiphase resonant current of the resonant cavity in the multiphase resonant converter is obtained through the sampling unit. The multiphase resonant current can be the multiphase current at a preset position in the resonant cavity. The preset position can be the current input position of the resonant cavity or the current output position of the resonant cavity.

[0071] The three-phase resonant current can be the amplitude, effective value, etc., and is not specifically limited in the embodiments of this application.

[0072] Due to differences in manufacturing processes, the resonant inductors Lr1, Lr2, and Lr3, as well as the resonant capacitors Cr1, Cr2, and Cr3, exhibit parameter variations. This leads to inconsistencies in the parameters of the corresponding components within the resonant cavity, resulting in significant deviations in the effective values ​​of the resonant currents across each phase and causing unbalanced power distribution among the phases. Consequently, the multiphase resonant currents obtained in the multiphase resonant converter typically differ considerably.

[0073] S202, based on the multiphase resonant current, determine at least two angle variation coefficients and the initial angle variation of each phase.

[0074] To achieve current sharing of the multiphase resonant current in the resonant cavity of a multiphase resonant converter, the phase angle of each phase needs to be changed to ensure that the multiphase resonant current obtained through the changed phase angles is balanced. Therefore, it is necessary to analyze the imbalance between the multiphase resonant currents based on the multiphase resonant currents to determine the angle data for changing the multiple phase angles.

[0075] In this embodiment of the application, the angle data for changing multiple phase angles includes at least two angle change coefficients and the initial angle change amount for each phase. The angle change coefficients can be understood as the degree or multiple of change in the phase angle, and the initial angle change amount can be understood as the increase or decrease in the phase angle.

[0076] S203, based on the magnitude relationship of the multiphase resonant currents, at least two angle variation coefficients, and the initial angle variation of each phase, determine the target angle variation of each phase.

[0077] After determining at least two angle change coefficients and the initial angle change of each phase, the target angle change of each phase can be determined based on these and the magnitude relationship of the multiphase resonant currents. For example, if one phase has a smaller resonant current, the resonant current of that phase needs to be increased, and the target angle change of that phase will be larger; if one phase has a larger resonant current, the resonant current of that phase needs to be decreased, and the target angle change of that phase will be smaller.

[0078] S204 controls the multiphase resonant converter to adjust the resonant current of each phase in the resonant cavity according to the target angle change of each phase.

[0079] After the target angle change of each phase is compared with the fixed phase angle between the multiple phases, the new phase angle of each phase can be obtained. Then, based on the new phase angle of each phase, the power switching transistors in the inverter circuit of the multiphase resonant converter can be controlled by the drive unit to control the resonant current of each phase in the resonant cavity so that it achieves current sharing.

[0080] For example, if the multiphase resonant converter is a three-phase resonant converter, Figure 3 This is a schematic diagram of a phase angle change provided in an embodiment of this application, as shown below. Figure 3 As shown, the fixed phase angle between the three phases is 120°, that is, the phase angle difference between the driving signal of the first phase A (path) and the driving signal of the second phase B is 120°, the phase angle difference between the driving signal of the second phase B and the driving signal of the third phase C is 120°, and the phase angle difference between the driving signal of the first phase A and the driving signal of the third phase C is 240°.

[0081] The new phase angle of the first phase A can be the change between the initial phase angle of the first phase (0°) and the target angle of the first phase. The sum, and so on, means that the new phase angle of the second phase B can be the sum of the initial phase angle of the second phase (120°) and the change in the target angle of the second phase. The sum of these factors gives the new phase angle of the third phase C the change between the initial phase angle of the third phase (240°) and the target angle of the third phase. sum.

[0082] Experimental data shows that the differences between the multiphase resonant currents are large when current sharing measures are not added, while the differences between the multiphase resonant currents are small after current sharing measures are added, which basically achieves current sharing in the resonant cavity during multiphase resonant transformation.

[0083] This application provides a current sharing control method for a multiphase resonant converter. The method involves obtaining the multiphase resonant current in the resonant cavity of the multiphase resonant converter, determining at least two angle variation coefficients and the initial angle variation of each phase based on the multiphase resonant current, determining the target angle variation of each phase based on the magnitude relationship of the multiphase resonant current, the at least two angle variation coefficients, and the initial angle variation of each phase, and controlling the multiphase resonant converter to adjust the resonant current of each phase in the resonant cavity based on the target angle variation of each phase. This method analyzes the multiphase resonant current to obtain the target angle variation of each phase, and then adjusts the resonant current of each phase in the resonant cavity based on the target angle variation of each phase, thereby achieving current sharing among the multiphase resonant currents and reducing the failure rate of the charging module.

[0084] Furthermore, in the above Figure 2 Based on the current sharing control method shown, this application embodiment also provides a method for determining at least two angle change coefficients and the initial angle change of each phase. Optionally, Figure 4 A flowchart illustrating a method for determining the angle change coefficient and the initial angle change amount provided in this application embodiment is shown below. Figure 4 As shown, the above method S202, based on the multiphase resonant current, determines at least two angle variation coefficients and the initial angle variation of each phase, including:

[0085] S401, based on the multiphase resonant current, determine the first reference current value and at least two second reference current values.

[0086] The first reference current value can be one of the phase currents in the multiphase resonant current.

[0087] Any one of the at least two second reference current values ​​can be one of the phase currents in the multiphase resonant current, or it can be a current value obtained by calculation of the multiphase resonant current. No specific limitation is made in the embodiments of this application.

[0088] S402, calculate at least two angle variation coefficients based on the first reference current value and at least two second reference current values.

[0089] An angle variation coefficient can be calculated based on the first reference current value and any second reference current value. Therefore, each angle variation coefficient is calculated from the first reference current value and a second reference current value.

[0090] S403 determines the initial angle change of each phase based on the first reference current value and the multiphase resonant current.

[0091] The initial angle change of each phase can be calculated based on the first reference current value and the current of any one phase in the multiphase resonant current. Therefore, the initial angle change of each phase is calculated from the first reference current value and the resonant current of that phase.

[0092] In the embodiments of this application, S402 can be executed first and S403 can be executed later, or S403 can be executed first and S402 can be executed later, or S402 and S403 can be executed simultaneously, that is, the order of S402 and S403 is not specifically limited.

[0093] This application provides a method for determining angle change coefficients and initial angle change amounts. Based on the multiphase resonant current, a first reference current value and at least two second reference current values ​​are determined. Based on the first reference current value and at least two second reference current values, at least two angle change coefficients are calculated respectively. Based on the first reference current value and the multiphase resonant current, the initial angle change amount of each phase is determined. Then, the target angle change amount of each phase can be determined by the at least two angle change coefficients and the initial angle change amount of each phase.

[0094] Furthermore, in the above Figure 4 Based on the method for determining the angle change coefficient and the initial angle change amount shown, this application embodiment also provides a method for determining a first reference current value and at least two second reference current values. Optionally, when the multiphase resonant converter is a three-phase resonant converter, the multiphase resonant current includes three-phase resonant currents, denoted as Ia, Ib, and Ic, respectively. In this case, the number of second reference current values ​​can be one.

[0095] The above method S401, based on the multiphase resonant current, determines a first reference current value and at least two second reference current values, including:

[0096] Based on the multiphase resonant currents, determine the maximum resonant current, minimum resonant current, and average resonant current. The maximum resonant current is the largest current among the multiphase resonant currents, the minimum resonant current is the smallest current among the multiphase resonant currents, and the average resonant current is the average current obtained by averaging the multiphase resonant currents. The maximum resonant current can be expressed as Imax, the minimum resonant current as Imin, and the average resonant current as Iavg.

[0097] In the embodiments of this application, the first reference current value is the maximum resonant current Imax, and the at least two second reference current values ​​include: the minimum resonant current Imin and the average resonant current Iavg.

[0098] It is understood that the first reference current value and at least two second reference current values ​​can also be current values ​​obtained by other calculations of the multiphase resonant current, and no specific limitations are imposed in the embodiments of this application.

[0099] This application provides a method for determining a first reference current value and at least two second reference current values. The multiphase resonant current includes a three-phase resonant current. Based on the multiphase resonant current, a maximum resonant current, a minimum resonant current, and an average resonant current are determined. The first reference current value is the maximum resonant current. The at least two second reference current values ​​include the minimum resonant current and the average resonant current. Then, the angle change coefficient can be calculated based on the reference current values.

[0100] Furthermore, in the above Figure 4 Based on the method for determining the angle change coefficient and the initial angle change amount shown, this application embodiment also provides a method for calculating at least two angle change coefficients. Optionally, Figure 5 This is a flowchart illustrating a method for calculating the angle change coefficient provided in an embodiment of this application, as shown below. Figure 5 As shown, in the above method S402, based on the first reference current value and at least two second reference current values, at least two angle change coefficients are calculated, including:

[0101] S501, calculate at least two current error parameters based on the first reference current value and at least two second reference current values.

[0102] A current error parameter can be calculated based on a first reference current value and a second reference current value. Specifically, the error between the first reference current value and the second reference current value can be calculated to obtain the current error parameter.

[0103] For example, if the multiphase resonant converter is a three-phase resonant converter, the first reference current value is the maximum resonant current Imax, and at least two second reference current values ​​include the minimum resonant current and the average resonant current, then two current error parameters can be calculated based on the maximum resonant current and the two second reference current values. Specifically, calculating the error between the maximum resonant current and the average resonant current yields one current error coefficient, and calculating the error between the maximum resonant current and the minimum resonant current yields another current error coefficient. It is understandable that the current error coefficient between the maximum resonant current and the average resonant current is smaller than the current error coefficient between the maximum resonant current and the minimum resonant current.

[0104] S502, calculate at least two angle variation coefficients based on at least two current error parameters.

[0105] Each current error parameter is input into the PI algorithm to obtain the corresponding angle change coefficient. The PI algorithm can also be called the PI operation loop.

[0106] For example, if the multiphase resonant converter is a three-phase resonant converter, there are two angle variation coefficients. The current error coefficient obtained by calculating the error between the maximum and average resonant currents is input into the PI algorithm to obtain one angle variation coefficient, denoted as k1. The current error coefficient obtained by calculating the error between the maximum and minimum resonant currents is input into the PI algorithm to obtain another angle variation coefficient, denoted as k2. It is understood that since the current error coefficient between the maximum and average resonant currents is smaller than that between the maximum and minimum resonant currents, k1 is smaller than k2, i.e., k1 is less than k2. Both k1 and k2 can be positive numbers.

[0107] This application provides a method for calculating the angle change coefficient. Based on a first reference current value and at least two second reference current values, at least two current error parameters are calculated respectively. Based on the at least two current error parameters, at least two angle change coefficients are calculated respectively, thereby enabling the calculation of the target angle change of each phase.

[0108] Furthermore, in the above Figure 4 Based on the method for determining the angle change coefficient and the initial angle change amount shown, this application embodiment also provides a method for determining the initial angle change amount. Optionally, Figure 6 This is a flowchart illustrating a method for determining the initial angle change provided in an embodiment of this application, as shown below. Figure 6 As shown, the above method S403 determines the initial angle change of each phase based on the first reference current value and the multiphase resonant current, including:

[0109] S601, determine the multiphase current error parameters based on the first reference current value and the multiphase resonant current.

[0110] Based on the first reference current value and the resonant current of one phase, the error parameter of the phase current can be calculated. Specifically, the error between the first reference current value and the resonant current of one phase can be calculated to obtain the error parameter of the phase current.

[0111] For example, if the multiphase resonant converter is a three-phase resonant converter, the first reference current value is the maximum resonant current Imax, and the multiphase resonant currents are represented as Ia, Ib, and Ic, then the error can be calculated between the maximum resonant current and Ia to obtain the phase current error parameter corresponding to Ia; the error can be calculated between the maximum resonant current and Ib to obtain the phase current error parameter corresponding to Ib; and the error can be calculated between the maximum resonant current and Ic to obtain the phase current error parameter corresponding to Ic.

[0112] S602, based on the multiphase current error parameters, determines the initial angle change of each phase.

[0113] The current error parameters of each phase are input into the PI algorithm to obtain the initial angle change of each phase. The PI algorithm can also be called the PI operation loop.

[0114] For example, if the multiphase resonant converter is a three-phase resonant converter, inputting the phase current error parameter corresponding to Ia into the PI algorithm yields the initial angle change of that phase, which can be represented as α; inputting the phase current error parameter corresponding to Ib into the PI algorithm yields the initial angle change of that phase, which can be represented as β; and inputting the phase current error parameter corresponding to Ic into the PI algorithm yields the initial angle change of that phase, which can be represented as γ. It is understood that α, β, and γ can contain both positive and negative values.

[0115] In this embodiment of the application, the maximum resonant current is used as the reference value of the resonant current of each phase, so that the resonant current of each phase tracks the maximum resonant current Imax, and then the direction of change of the angle of each phase is obtained by the PI algorithm, that is, the initial angle change of each phase is α, β, γ respectively.

[0116] This application provides a method for determining the initial angle change. Based on a first reference current value and a multiphase resonant current, multiphase current error parameters are determined respectively. Based on the multiphase current error parameters, the initial angle change of each phase is determined respectively, and then the target angle change of each phase can be calculated.

[0117] Furthermore, in the above Figure 2 Based on the current sharing control method shown, this application embodiment also provides a method for determining the target angle change of each phase. Optionally, Figure 7 This is a flowchart illustrating a method for determining the change in target angle provided in an embodiment of this application, as shown below. Figure 7 As shown, the above method S203 determines the target angle change of each phase based on the magnitude relationship of the multiphase resonant currents, at least two angle change coefficients, and the initial angle change of each phase, including:

[0118] S701, based on the magnitude relationship of the multiphase resonant currents and at least two angle variation coefficients, determine the angle variation coefficient of each phase.

[0119] To achieve current sharing among the multi-phase resonant currents, if one phase resonant current is large, its current value needs to be reduced, meaning the corresponding angle also needs to be reduced. Therefore, a suitable angle variation coefficient needs to be applied to ensure the reduction in current is sufficient. Similarly, if one phase resonant current is small, its current value needs to be increased, meaning the corresponding angle also needs to be increased. Again, a suitable angle variation coefficient needs to be applied to ensure the increase in current is sufficient.

[0120] It is understandable that at least two angle variation coefficients can be allocated to at least two phase resonant currents.

[0121] S702, based on the angle change coefficient of each phase and the initial angle change of each phase, determine the target angle change of each phase respectively.

[0122] After determining the angle change coefficient of each phase, the target angle change of each phase can be obtained by multiplying the angle change coefficient of each phase with the initial angle change of each phase.

[0123] For example, if there exists a phase with an angle change coefficient of k1 and an initial angle change of α, then the target angle change of that phase is... Then the new phase angle of this phase can be the initial phase angle of 0° and... sum.

[0124] This application provides a method for determining the target angle change. Based on the magnitude relationship of the multiphase resonant current and at least two angle change coefficients, the angle change coefficient of each phase is determined. Based on the angle change coefficient of each phase and the initial angle change of each phase, the target angle change of each phase is determined respectively. In this way, the new phase angle of each phase can be obtained to control each power switch in the inverter circuit of the multiphase resonant converter.

[0125] Furthermore, in the above Figure 7 Based on the method for determining the target angle change shown, this application embodiment also provides a method for determining the angle change coefficient of each phase. Optionally, Figure 8 This is a flowchart illustrating a method for determining an angle change coefficient provided in an embodiment of this application, as shown below. Figure 8 As shown, the above method S701 determines the angle variation coefficient of each phase based on the magnitude relationship of the multiphase resonant currents and at least two angle variation coefficients, including:

[0126] S801, based on the magnitude relationship of the multiphase resonant currents, determines the angle variation coefficient of the target phase corresponding to the maximum resonant current as the preset reference variation coefficient.

[0127] In this embodiment, the maximum resonant current in the multiphase resonant current is determined according to the magnitude relationship of the multiphase resonant currents, and the angle variation coefficient of the target phase allocation of the maximum resonant current is a preset reference variation coefficient.

[0128] For example, the preset baseline degradation factor can be 1, or it can be other numbers, and no specific restrictions are imposed in the embodiments of this application.

[0129] S802, based on the magnitude relationship of the multiphase resonant current, determines the angle variation coefficients of each phase other than the target phase from at least two angle variation coefficients.

[0130] Among them, the larger the resonant current of each other phase, the smaller the angle change coefficient.

[0131] For example, if the multiphase resonant converter is a three-phase resonant converter, the resonant current of phase A is denoted as Ia, the resonant current of phase B as Ib, and the resonant current of phase C as Ic. Based on these three-phase resonant currents, two angle change coefficients, k1 and k2, are determined, where k1 is less than k2. The initial angle changes of each phase are also determined as α (corresponding to phase A), β (corresponding to phase B), and γ (corresponding to phase C). If the magnitude relationship of the multiphase resonant currents is Ia > Ib > Ic, then the angle change coefficient of the target phase A corresponding to the maximum resonant current Ia is a preset reference change coefficient 1, i.e., the target angle change of phase A. The target phase C corresponding to the minimum resonant current Ic has the largest angular change coefficient, which is k2, i.e., the target angular change of phase C. If the resonant current Ib of phase B is greater than the resonant current Ic, then the angular change coefficient of the target phase B corresponding to the resonant current Ib of phase B is smaller, which is k1, that is, the target angular change of phase B. Similarly, if the magnitudes of the multiphase resonant currents are Ib>Ic>Ia, then the angle variation coefficients of phases B, C, and A are the preset reference variation coefficients 1, k1, and k2, respectively. Therefore, the target angle variation ratios of phases A, B, and C are k2*α, β, and k1*γ. If the magnitudes of the multiphase resonant currents are Ic>Ia>Ib, then the target angle variation ratios of phases A, B, and C are k1*α, k2*β, and γ. Of course, the magnitudes of the multiphase resonant currents may also have other relationships; the methods for determining the corresponding angle variation coefficients for each phase will not be elaborated upon here.

[0132] This application provides a method for determining the angle change coefficient. Based on the magnitude relationship of the multiphase resonant currents, the angle change coefficient of the target phase corresponding to the maximum resonant current is determined as a preset reference change coefficient. Based on the magnitude relationship of the multiphase resonant currents, the angle change coefficients of each other phases other than the target phase are determined from at least two angle change coefficients. The larger the resonant current of each other phase, the smaller the angle change coefficient. Thus, the angle change coefficients of each phase can be obtained to calculate the target angle change of each phase.

[0133] In the above embodiments of this application Figures 2 to 8 Based on the provided current sharing control method, the following detailed explanation of the current sharing control method for a multiphase resonant converter is provided with reference to the accompanying drawings through a complete embodiment. Figure 9This is a flowchart illustrating another current sharing control method for a multiphase resonant converter provided in an embodiment of this application. Figure 9 As shown, the method includes:

[0134] S901, obtains the multiphase resonant current of the resonant cavity in the multiphase resonant converter.

[0135] For a detailed description of the implementation and effects of the S901, please refer to the above. Figure 2 S201 in the text will not be elaborated upon here.

[0136] S902, based on the multiphase resonant current, determine the first reference current value and at least two second reference current values.

[0137] For a detailed implementation and effect description of the S902, please refer to the above. Figure 4 The S401 in the text will not be elaborated upon here.

[0138] S903, calculate at least two current error parameters based on the first reference current value and at least two second reference current values; calculate at least two angle variation coefficients based on the at least two current error parameters.

[0139] For a detailed description of the implementation and effects of the S903, please refer to the above. Figure 5 S501 and S502 in the above will not be described in detail here.

[0140] S904, based on the first reference current value and the multiphase resonant current, determine the multiphase current error parameters respectively; based on the multiphase current error parameters, determine the initial angle change of each phase respectively.

[0141] For a detailed description of the implementation and effects of the S904, please refer to the above. Figure 6 S601 and S602 in the above will not be described in detail here.

[0142] The execution order of S903 and S904 is not subject to excessive restrictions in this embodiment.

[0143] S905, based on the magnitude relationship of the multiphase resonant currents, determines the angle variation coefficient of the target phase corresponding to the maximum resonant current as the preset reference variation coefficient.

[0144] For a detailed description of the implementation and effects of the S905, please refer to the above. Figure 8 The S801 in this context will not be discussed further here.

[0145] S906, based on the magnitude relationship of the multiphase resonant current, determines the angle variation coefficients of each phase other than the target phase from at least two angle variation coefficients.

[0146] Among them, the larger the resonant current of each other phase, the smaller the angle change coefficient.

[0147] For a detailed description of the implementation and effects of the S906, please refer to the above. Figure 8 The S802 in the text will not be elaborated upon here.

[0148] S907, based on the angle change coefficient of each phase and the initial angle change of each phase, determine the target angle change of each phase respectively.

[0149] For a detailed description of the implementation and effects of the S907, please refer to the above. Figure 7 The S702 mentioned above will not be elaborated upon here.

[0150] S908 controls the multiphase resonant converter to adjust the resonant current of each phase in the resonant cavity according to the target angle change of each phase.

[0151] For a detailed description of the implementation and effects of the S908, please refer to the above. Figure 2 S204 in the text will not be elaborated upon here.

[0152] In the experiment, for example, if the multiphase resonant converter is a three-phase resonant converter, an experimental simulation circuit is built, and the two-phase resonant inductors Lr2 and Lr3 and their corresponding resonant capacitors Cr2 and Cr3 are negatively biased by 10%, while the other phase resonant inductor Lr1 and its corresponding resonant capacitor Cr1 are positively biased by 10%, and the current sharing effect is observed in the experiment. Figure 10 This is a schematic diagram illustrating experimental results without employing a flow sharing strategy, as provided in an embodiment of this application. Figure 11 This is a schematic diagram of the experimental results using a current-sharing strategy provided in an embodiment of this application. The resonant current waveform of the resonant cavity obtained after simulation is as follows: Figure 10 and Figure 11 As shown, it can be seen that without the flow sharing strategy... Figure 10 The current imbalance corresponding to the three current waveforms in the middle three is addressed by the current sharing control method proposed in this application. Figure 11 The currents corresponding to the three current waveforms in the middle three are compared. Figure 10 More balanced, that is, the current sharing control method proposed in this application can achieve the current sharing effect of multiphase resonant converter very well.

[0153] The experimental data using the current sharing strategy are as follows: the resonant currents of phases A, B, and C are 38A, 31.22A, and 37.88A, respectively. The experimental data using the current sharing control method proposed in this application are as follows: the resonant currents of phases A, B, and C are 36A, 35.15A, and 35.24A, respectively. It can be seen that the current sharing control method proposed in this application can basically achieve current sharing.

[0154] The following describes a flow sharing control device, control unit, and storage medium provided in this application for implementation. The specific implementation process and technical effects are described above and will not be repeated below.

[0155] Figure 12 This is a schematic diagram of a flow sharing control device provided in an embodiment of this application, as shown below. Figure 12 As shown, the flow sharing control device includes:

[0156] The acquisition module 1201 is used to acquire the multiphase resonant current of the resonant cavity in the multiphase resonant converter;

[0157] The first determining module 1202 is used to determine at least two angle variation coefficients and the initial angle variation of each phase based on the multiphase resonant current.

[0158] The second determining module 1203 is used to determine the target angle change of each phase based on the magnitude relationship of the multiphase resonant current, the at least two angle change coefficients, and the initial angle change of each phase.

[0159] The control module 1204 is used to control the multiphase resonant converter to adjust the resonant current of each phase of the resonant cavity according to the target angle change of each phase.

[0160] Optionally, the first determining module 1202 is specifically used to determine a first reference current value and at least two second reference current values ​​based on the multiphase resonant current; calculate at least two angle change coefficients based on the first reference current value and at least two second reference current values; and determine the initial angle change of each phase based on the first reference current value and the multiphase resonant current.

[0161] Optionally, the first determining module 1202 is specifically used for the multiphase resonant current including: three-phase resonant current; determining a first reference current value and at least two second reference current values ​​based on the multiphase resonant current, including: determining the maximum resonant current, the minimum resonant current and the average resonant current based on the multiphase resonant current; the first reference current value is the maximum resonant current, and the at least two second reference current values ​​include: the minimum resonant current and the average resonant current.

[0162] Optionally, the first determining module 1202 is specifically used to calculate at least two current error parameters based on the first reference current value and at least two second reference current values; and to calculate at least two angle change coefficients based on the at least two current error parameters.

[0163] Optionally, the first determining module 1202 is specifically used to determine the multiphase current error parameters according to the first reference current value and the multiphase resonant current; and to determine the initial angle change of each phase according to the multiphase current error parameters.

[0164] Optionally, the second determining module 1203 is specifically used to determine the angle change coefficient of each phase based on the magnitude relationship of the multiphase resonant current and at least two angle change coefficients; and to determine the target angle change of each phase based on the angle change coefficient of each phase and the initial angle change of each phase.

[0165] Optionally, the second determining module 1203 is specifically used to determine the angle change coefficient of the target phase corresponding to the maximum resonant current as a preset reference change coefficient based on the magnitude relationship of the multiphase resonant currents; and to determine the angle change coefficients of each other phase in each phase other than the target phase from at least two angle change coefficients based on the magnitude relationship of the multiphase resonant currents; wherein, the larger the resonant current of each other phase, the smaller the angle change coefficient.

[0166] These modules can be one or more integrated circuits configured to implement the above methods, such as one or more Application Specific Integrated Circuits (ASICs), one or more digital signal processors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs). Alternatively, when a module is implemented using processing element scheduler code, the processing element can be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor capable of calling program code. Furthermore, these modules can be integrated together as a system-on-a-chip (SOC).

[0167] Figure 13 This is a schematic diagram of a control unit provided in an embodiment of this application. The control unit may be a unit or device with computing processing functions.

[0168] The control unit includes a processor 1301, a storage medium 1302, and a bus 1303. The processor 1301 and the storage medium 1302 are connected via the bus 1303.

[0169] Storage medium 1302 is used to store programs, and processor 1301 calls the programs stored in storage medium 1302 to execute the above method embodiments. The specific implementation and technical effects are similar, and will not be described again here.

[0170] Optionally, the present invention also provides a program product, such as a computer-readable storage medium, including a program that, when executed by a processor, is used to perform the above-described method embodiments.

[0171] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0172] The units described as separate components may or may not be physically separate. The 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 the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0173] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or in the form of hardware plus software functional units.

[0174] The integrated units implemented as software functional units described above can be stored in a computer-readable storage medium. These software functional units, stored in a storage medium, include several instructions to cause a processor in a computer device (which may be a personal computer, server, or network device, etc.) or control unit to execute some steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0175] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A current sharing control method for a multiphase resonant converter, characterized in that, The method includes: Obtain the multiphase resonant current in the resonant cavity of a multiphase resonant converter; Based on the multiphase resonant current, at least two angle variation coefficients and the initial angle variation of each phase are determined; Based on the magnitude relationship of the multiphase resonant currents, the at least two angle variation coefficients, and the initial angle variation of each phase, the target angle variation of each phase is determined; the larger the resonant current of each phase, the smaller the corresponding angle variation coefficient. Based on the target angle change of each phase, the multiphase resonant converter is controlled to adjust the resonant current of each phase of the resonant cavity; The step of determining at least two angle variation coefficients and the initial angle variation of each phase based on the multiphase resonant current includes: Based on the multiphase resonant current, a first reference current value and at least two second reference current values ​​are determined; Calculate at least two current error parameters based on the first reference current value and at least two second reference current values; Calculate the at least two angle variation coefficients based on the at least two current error parameters; The initial angle change of each phase is determined based on the first reference current value and the multiphase resonant current.

2. The flow sharing control method according to claim 1, characterized in that, The multiphase resonant current includes: three-phase resonant current; The step of determining the first reference current value and at least two second reference current values ​​based on the multiphase resonant current includes: Based on the multiphase resonant current, the maximum resonant current, the minimum resonant current, and the average resonant current are determined; the first reference current value is the maximum resonant current, and the at least two second reference current values ​​include the minimum resonant current and the average resonant current.

3. The flow sharing control method according to claim 1, characterized in that, The step of determining the initial angle change of each phase based on the first reference current value and the multiphase resonant current includes: Based on the first reference current value and the multiphase resonant current, the multiphase current error parameters are determined respectively; Based on the multiphase current error parameters, the initial angle change of each phase is determined.

4. The flow sharing control method according to claim 1, characterized in that, The step of determining the target angle change of each phase based on the magnitude relationship of the multiphase resonant currents, the at least two angle change coefficients, and the initial angle change of each phase includes: The angle variation coefficient of each phase is determined based on the magnitude relationship of the multiphase resonant currents and the at least two angle variation coefficients. Based on the angle change coefficient of each phase and the initial angle change of each phase, the target angle change of each phase is determined respectively.

5. The flow sharing control method according to claim 4, characterized in that, The step of determining the angle variation coefficient of each phase based on the magnitude relationship of the multiphase resonant currents and the at least two angle variation coefficients includes: Based on the magnitude relationship of the multiphase resonant currents, the angle variation coefficient of the target phase corresponding to the maximum resonant current is determined as the preset reference variation coefficient; Based on the magnitude relationship of the multiphase resonant currents, the angle variation coefficients of each phase other than the target phase are determined from the at least two angle variation coefficients.

6. A flow sharing control device, characterized in that, include: The acquisition module is used to acquire the multiphase resonant current of the resonant cavity in the multiphase resonant converter; The first determining module is used to determine at least two angle variation coefficients and the initial angle variation of each phase based on the multiphase resonant current. The second determining module is used to determine the target angle change of each phase based on the magnitude relationship of the multiphase resonant currents, the at least two angle change coefficients, and the initial angle change of each phase; the larger the resonant current of each phase, the smaller the corresponding angle change coefficient. The control module is used to control the multiphase resonant converter to adjust the resonant current of each phase of the resonant cavity according to the target angle change of each phase; Specifically, the first determining module is used to determine a first reference current value and at least two second reference current values ​​based on the multiphase resonant current; calculate at least two current error parameters based on the first reference current value and at least two second reference current values; calculate at least two angle change coefficients based on the at least two current error parameters; and determine the initial angle change of each phase based on the first reference current value and the multiphase resonant current.

7. A control unit, characterized in that, include: A storage medium and a processor, the storage medium storing a computer program executable by the processor, wherein the processor, when executing the computer program, implements the current sharing control method for the multiphase resonant converter according to any one of claims 1-5.

8. A power electronic module, characterized in that, include: The system comprises a sampling unit, a control unit, a drive unit, and a multiphase resonant converter; the control unit is the control unit described in claim 7 above. The sampling unit's acquisition end is connected to the resonant cavity in the multiphase resonant converter, and the sampling unit's output end is connected to the control unit. The control unit is also connected to the control end of the multiphase resonant converter through the driving unit.

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