Power supply control method, power supply control device, and electrical system

Abstract

The application provides a power supply control method, a power supply control device and an electrical system. The method comprises the following steps: acquiring a common output voltage of a plurality of DC-DC conversion circuits connected in parallel and output currents of the DC-DC conversion circuits; determining a reference waveform parameter according to a voltage difference between the common output voltage and a reference output voltage; determining phase shift parameters of the DC-DC conversion circuits respectively according to current differences between average currents of the output currents; and determining target waveform parameters of the DC-DC conversion circuits respectively according to the phase shift parameters and the reference waveform parameter. Firstly, different phase shift parameters are obtained based on the differences between the output currents, the DC-DC conversion circuits are phase shifted to different degrees, and then current sharing among the DC-DC conversion circuits is realized. Secondly, the common output voltage is only used for voltage stabilization, and the output currents are only used for phase shift and current sharing, so that the voltage stabilization and the phase shift and current sharing are independent and do not affect each other, and the current sharing effect is further improved.

Description

Technical Field

[0001] This invention relates to the field of power supply technology, specifically to a power supply control method, a power supply control device, and an electrical system. Background Technology

[0002] Against the backdrop of the rapid development of power electronic power conversion industries such as energy storage and AIDC, the capacity requirements of power conversion devices in new energy generation, grid, and user systems are constantly increasing. As the core power unit of the overall system, the single-unit power limit of the DC-DC converter circuit has become a key bottleneck for system expansion. To overcome this limitation, parallel operation of multiple DC-DC converter circuits has become the mainstream technical solution. This solution can flexibly expand the system power through stacking, while also offering advantages such as redundancy backup and convenient maintenance.

[0003] Existing DC-DC converter circuits have certain design flaws, which can easily generate circulating currents within them. This causes their output current to differ significantly from that of other DC-DC converter circuits, ultimately leading to uneven current distribution among the various DC-DC converter circuits. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the present invention provides a power supply control method, a power supply control device and an electrical system.

[0005] In one aspect, the present invention provides a power supply control method applied to a power supply control device, the power supply control device including a control circuit and a plurality of DC-DC converter circuits connected in parallel, the control circuit being electrically connected to each DC-DC converter circuit respectively; the power supply control method includes the following steps performed by the control circuit: Obtain the common output voltage of multiple DC-DC converter circuits and the output current of each DC-DC converter circuit; The reference waveform parameters are determined based on the voltage difference between the common output voltage and the reference output voltage. Determine the average current between each output current, and based on the current difference between each output current and the average current, determine the phase shift parameters of each DC-DC converter circuit. Based on each phase shift parameter and reference waveform parameter, the target waveform parameters of each DC-DC converter circuit are determined, and the switching control of each DC-DC converter circuit is performed through each target waveform parameter.

[0006] In one embodiment, two DC-DC converter circuits are provided; the phase shift parameters of each DC-DC converter circuit are determined based on the current difference between each output current and the average current, including: For each DC-DC converter circuit, the phase shift parameters of another DC-DC converter circuit are determined based on the current difference between the output current and the average current of that DC-DC converter circuit.

[0007] In one embodiment, determining the phase shift parameters of another DC-DC converter circuit based on the current difference between the output current and the average current of the DC-DC converter circuit includes: The phase shift step size of another DC-DC converter circuit is determined based on the current difference between the output current and the average current of the first DC-DC converter circuit. The larger the current difference between the output current and the average current of the first DC-DC converter circuit, the larger the phase shift step size of the other DC-DC converter circuit. The phase shift parameters include the phase shift step size. Based on the phase shift parameters and reference waveform parameters, the target waveform parameters for each DC-DC converter circuit are determined. The switching control of each DC-DC converter circuit is then performed using these target waveform parameters, including: For each DC-DC converter circuit: The phase shift angle step size of the DC-DC converter circuit is used as the current phase shift angle of the DC-DC converter circuit. Based on the current phase shift angle of the DC-DC converter circuit, the reference waveform parameters are phase shifted to obtain the target waveform parameters of the DC-DC converter circuit. The DC-DC converter circuit is then switched on and off using the target waveform parameters of the DC-DC converter circuit. Based on the phase shift step size of the DC-DC converter circuit, the current phase shift angle of the DC-DC converter circuit is accumulated to obtain the new current phase shift angle of the DC-DC converter circuit. Based on the new current phase shift angle of the DC-DC converter circuit, the reference waveform parameters are phase shifted to obtain the new target waveform parameters of the DC-DC converter circuit. The DC-DC converter circuit is then switched on and off using the new target waveform parameters of the DC-DC converter circuit.

[0008] In one embodiment, determining the phase shift step size of another DC-DC converter circuit based on the current difference between the output current and the average current of the DC-DC converter circuit includes: The number of divisions is determined based on the current difference between the output current and the average current of the DC-DC converter circuit. Based on this division number, the circumference is divided equally to obtain the phase shift angle step size of another DC-DC converter circuit.

[0009] In one embodiment, the number of divisions is determined based on the current difference between the output current and the average current of the DC-DC converter circuit, including: The corresponding phase shift period is determined based on the current difference between the output current and the average current of the DC-DC converter circuit. The number of divisions is obtained based on the ratio of the phase shift period to the switching period corresponding to the reference waveform parameters.

[0010] In one embodiment, based on the phase shift step size of the DC-DC converter circuit, the current phase shift angle of the DC-DC converter circuit is accumulated to obtain a new current phase shift angle of the DC-DC converter circuit, including: After completing the switching control of the DC-DC converter circuit for one switching cycle, the current phase shift angle of the DC-DC converter circuit is accumulated according to the phase shift angle step size of the DC-DC converter circuit to obtain the new current phase shift angle of the DC-DC converter circuit.

[0011] In one embodiment, determining the average current among the output currents includes: Determine the current difference between each output current; If the current difference between each output current exceeds the preset current difference, then the average current between each output current is determined.

[0012] In a second aspect, in one embodiment, the present invention provides a power supply control device, which includes a control circuit and a plurality of DC-DC converter circuits connected in parallel, wherein the control circuit is electrically connected to each DC-DC converter circuit; the control circuit is used to implement the power supply control method in any of the above embodiments.

[0013] In one embodiment, the DC-DC converter circuit includes a three-phase star LLC resonant converter.

[0014] Thirdly, in one embodiment, the present invention provides an electrical system including a DC power supply, a DC load, and a power supply control device as described in any of the above embodiments; The input terminal of each DC-DC converter circuit is electrically connected to a DC power supply, and the output terminal of each DC-DC converter circuit is electrically connected to a DC load.

[0015] Through the aforementioned power supply control method, power supply control device, and electrical system, the common output voltage of multiple DC-DC converter circuits and the output current of each DC-DC converter circuit are obtained. On the one hand, the reference waveform parameters are determined based on the voltage difference between the common output voltage and the reference output voltage. On the other hand, the phase shift parameters of each DC-DC converter circuit are determined based on the average current between each output current. Thus, the target waveform parameters of each DC-DC converter circuit are determined based on the phase shift parameters and the reference waveform parameters. Subsequently, each DC-DC converter circuit is switched on and off based on the target waveform parameters. First, different phase shift parameters are obtained based on the differences between the output currents, thereby achieving different degrees of phase shift in each DC-DC converter circuit, and thus achieving current sharing among the DC-DC converter circuits. Second, the common output voltage is only used to achieve voltage regulation, and each output current is only used to achieve phase shift current sharing, so that voltage regulation and phase shift current sharing are independent and do not affect each other, thereby further improving the current sharing effect. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the power supply control device in one embodiment of the present invention; Figure 2 This is a flowchart illustrating a power supply control method in one embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the power supply control device further including a PFM waveform generator in one embodiment of the present invention; Figure 4 This is a schematic diagram of the logic processing of a power supply control method in one embodiment of the present invention; Figure 5 This is a schematic diagram of the power supply control device, specifically including a three-phase star-type LLC resonant converter, in one embodiment of the present invention. Figure 6 This is a schematic diagram of a three-phase star-type LLC resonant converter in one embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified. In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to implement and use the invention. In the following description, details are set forth for purposes of explanation. It should be understood that those skilled in the art will recognize that the invention can be implemented without using these specific details. In other instances, well-known structures and processes will not be described in detail to avoid obscuring the description of the invention with unnecessary detail. Therefore, the invention is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed herein.

[0020] In one embodiment, the present invention provides a power supply control method applied to a power supply control device, such as... Figure 1 As shown, the power supply control device includes a control circuit and multiple DC-DC converter circuits connected in parallel. The control circuit is electrically connected to each DC-DC converter circuit. The input terminals of each DC-DC converter circuit are used to be electrically connected to a DC power supply, and the output terminals of each DC-DC converter circuit are used to be electrically connected to a DC load.

[0021] like Figure 2 As shown, the power supply control method includes the following steps executed by the control circuit: Step 101: Obtain the common output voltage of multiple DC-DC converter circuits and the output current of each DC-DC converter circuit.

[0022] Among them, the common output voltage Vbus is a parallel voltage that is output to the DC load by multiple DC-DC converter circuits, and the output voltages of each DC-DC converter circuit are mutually clamped.

[0023] in, Figure 1 The diagram illustrates two DC-DC converters, where the output currents of each DC-DC converter circuit include output current I1 and output current I2, respectively. In other embodiments, a greater number of DC-DC converter circuits may be included to obtain a greater number of output currents.

[0024] Understandably, the power supply control device also includes Figure 1 Voltage detection circuit and multiple current detection circuits are not shown in the diagram.

[0025] Specifically, the input terminal of the voltage detection circuit is electrically connected to the output terminal of each DC-DC converter circuit, and the output terminal of the voltage detection circuit is electrically connected to the voltage input terminal of the control circuit. It is used to detect the common output voltage Vbus and provide feedback to the control circuit. The input terminal of each current detection circuit is electrically connected to the output terminal of the corresponding DC-DC converter circuit, and the output terminal of each current detection circuit is electrically connected to the corresponding current input terminal of the control circuit. Each current detection circuit is used to detect each output current (including output current I1 and output current I2) and provide feedback to the control circuit.

[0026] Step 102: Determine the reference waveform parameters based on the voltage difference between the common output voltage and the reference output voltage.

[0027] Wherein, the reference output voltage Vref is the desired voltage, the common output voltage Vbus is the actual voltage, and the voltage difference between the common output voltage Vbus and the reference output voltage Vref is... =Vbus-Vref, which can be determined based on the voltage difference. The sign and amplitude of the signal are used to control the switching of each DC-DC converter circuit.

[0028] The reference waveform parameters are used to characterize the initial control waveforms for subsequent switching control of each DC-DC converter circuit. The initial control waveform can be an initial PFM (Pulse Frequency Modulation) waveform; a higher switching frequency of the initial PFM waveform results in a larger common output voltage Vbus, and a lower switching frequency results in a smaller common output voltage Vbus. Alternatively, the initial control waveform can be a PWM (Pulse Width Modulation) waveform; a larger pulse width of the initial PWM waveform results in a larger common output voltage Vbus, and a smaller pulse width results in a smaller common output voltage Vbus.

[0029] Specifically, taking the initial PFM waveform as an example, if the voltage difference... A positive value indicates that the common output voltage Vbus is greater than the reference output voltage Vref. Therefore, the switching frequency of the initial PFM waveform, as represented by the obtained reference waveform parameters, is lower than the original PFM waveform, with the degree of reduction corresponding to the magnitude of the voltage difference. Similarly, if the voltage difference... If the value is negative, it means that the common output voltage Vbus is less than the reference output constant voltage Vref. In this case, the switching frequency of the initial PFM waveform characterized by the obtained reference waveform parameters is higher than that of the original PFM waveform, and the degree of improvement corresponds to the magnitude of the voltage difference.

[0030] Step 103: Determine the average current between each output current, and determine the phase shift parameters of each DC-DC converter circuit based on the current difference between each output current and the average current.

[0031] Taking two DC-DC converter circuits as an example, the average current Iavg = (I1 + I2) / 2. The average current Iavg is the desired current to achieve current sharing, while the output currents I1 and I2 are the actual currents. The current difference between the output current I1 and the average current Iavg is... =I1-Iavg, the current difference between the output current I2 and the average current Iavg =I²-Iavg, which can be determined based on the current difference. and current difference To perform current sharing control on each DC-DC converter circuit separately.

[0032] In this approach, without considering current sharing, the same initial control waveform is used to control the switching of each DC-DC converter circuit to achieve voltage regulation. When the phase of the initial control waveform corresponding to a certain DC-DC converter circuit changes, the internal circulating current of that DC-DC converter circuit also changes, causing the output current of that DC-DC converter circuit to change as well.

[0033] Therefore, in this embodiment, when current sharing control is required, the initial control waveform can be phase-shifted. The phase-shifting parameters characterize the phase-shifting strategy of the initial control waveform corresponding to the DC-DC converter circuit, mainly including the phase-shifting angle and the phase-shifting direction.

[0034] Step 104: Determine the target waveform parameters of each DC-DC converter circuit based on each phase shift parameter and the reference waveform parameter, and control the switching of each DC-DC converter circuit according to each target waveform parameter.

[0035] As mentioned above, the reference waveform parameter represents the initial control waveform, and the phase shift parameter represents the phase shifting processing strategy of the initial control waveform. The target waveform parameter determined based on the phase shift parameter and the reference waveform parameter represents the target control waveform obtained after the initial control waveform has undergone phase shifting processing. Although each DC-DC converter circuit uses the same initial control waveform, the target control waveform of each DC-DC converter circuit is different because the phase shifting processing strategies of each DC-DC converter circuit are different.

[0036] Specifically, if the initial control waveform is the initial PFM waveform, then the target control waveform after phase shifting is the target PFM waveform; if the initial control waveform is the initial PWM waveform, then the target control waveform after phase shifting is the target PWM waveform.

[0037] Understandably, the target waveform parameters obtained by the control circuit are used to instruct the corresponding waveform generator to output the corresponding target control waveform. Taking PFM waveforms as an example... Figure 3 As shown, the power supply control device also includes a PFM waveform generator. After determining the target waveform parameters of each DC-DC conversion circuit, the control circuit can control the PFM waveform generator to output the corresponding target PFM waveform to each DC-DC conversion circuit.

[0038] The power supply control method described above obtains the common output voltage of multiple DC-DC converter circuits and the output current of each DC-DC converter circuit. On the one hand, the reference waveform parameters are determined based on the voltage difference between the common output voltage and the reference output voltage. On the other hand, the phase shift parameters of each DC-DC converter circuit are determined based on the average current between each output current. Thus, the target waveform parameters of each DC-DC converter circuit are determined based on the phase shift parameters and the reference waveform parameters. Subsequently, the switching control of each DC-DC converter circuit is performed based on the target waveform parameters. First, different phase shift parameters are obtained based on the differences between the output currents, thereby achieving different degrees of phase shifting in each DC-DC converter circuit, and thus achieving current sharing among the DC-DC converter circuits. Second, the common output voltage is only used to achieve voltage regulation, and each output current is only used to achieve phase shifting and current sharing, so that voltage regulation and phase shifting and current sharing are independent and do not affect each other, thereby further improving the current sharing effect.

[0039] like Figure 1 As shown, in one embodiment, two DC-DC converter circuits are provided; based on the current difference between each output current and the average current, the phase shift parameters of each DC-DC converter circuit are determined, including: For each DC-DC converter circuit, the phase shift parameters of another DC-DC converter circuit are determined based on the current difference between the output current and the average current of that DC-DC converter circuit.

[0040] For the first DC-DC converter circuit, based on the current difference between the output current I1 and the average current Iavg... To determine the phase shift parameters of the second DC-DC converter circuit; for the second DC-DC converter circuit, based on the current difference between the output current I2 and the average current Iavg. This determines the phase shift parameters of the first DC-DC converter circuit. That is, the final target control waveform of the first DC-DC converter circuit is determined by the current difference. It is determined that the final target control waveform of the second DC-DC converter circuit is determined by the current difference. Confirmed. That is to say, the current difference. Used to indicate the phase shift and current difference of the second DC-DC converter circuit relative to the first DC-DC converter circuit. Used to indicate the phase shift of the first DC-DC converter circuit relative to the second DC-DC converter circuit.

[0041] It is understandable that when there is a difference between the output current I1 and the output current I2, the average current Iavg must be between the output current I1 and the output current I2, so that the current difference... and current difference One of them is positive and the other is negative, so that the initial control waveforms corresponding to the two DC-DC conversion circuits are phase-shifted in different directions to obtain the corresponding target control waveforms.

[0042] In one embodiment, determining the phase shift parameters of another DC-DC converter circuit based on the current difference between the output current and the average current of the DC-DC converter circuit includes: The phase shift step size of another DC-DC converter circuit is determined based on the current difference between the output current and the average current of the first DC-DC converter circuit. The larger the current difference between the output current and the average current of the first DC-DC converter circuit, the larger the phase shift step size of the other DC-DC converter circuit. The phase shift parameters include the phase shift step size.

[0043] For the first DC-DC converter circuit, based on the current difference between the output current I1 and the average current Iavg... To determine the phase shift step size of the second DC-DC converter circuit. Current difference The larger the step size, the larger the phase shift angle. The larger the value; for the second DC-DC converter circuit, based on the current difference between the output current I2 and the average current Iavg. Determine the phase shift step size of the first DC-DC converter circuit. 1. Current difference The larger 2 is, the larger the phase shift step size. The larger.

[0044] The larger the current difference, the greater the need for current sharing. Therefore, in this embodiment, the phase shift angle step is increased to make the initial control waveform corresponding to the DC-DC converter circuit undergo a greater phase shift, thereby meeting the current sharing requirements.

[0045] Based on the phase shift parameters and reference waveform parameters, the target waveform parameters for each DC-DC converter circuit are determined. The switching control of each DC-DC converter circuit is then performed using these target waveform parameters, including: For each DC-DC converter circuit: The phase shift angle step size of the DC-DC converter circuit is used as the current phase shift angle of the DC-DC converter circuit. Based on the current phase shift angle of the DC-DC converter circuit, the reference waveform parameters are phase shifted to obtain the target waveform parameters of the DC-DC converter circuit. The DC-DC converter circuit is then switched on and off using the target waveform parameters of the DC-DC converter circuit. Based on the phase shift step size of the DC-DC converter circuit, the current phase shift angle of the DC-DC converter circuit is accumulated to obtain the new current phase shift angle of the DC-DC converter circuit. Based on the new current phase shift angle of the DC-DC converter circuit, the reference waveform parameters are phase shifted to obtain the new target waveform parameters of the DC-DC converter circuit. The DC-DC converter circuit is then switched on and off using the new target waveform parameters of the DC-DC converter circuit.

[0046] For the first DC-DC converter circuit, the phase shift step size is first set. The current phase shift angle is used to shift the initial control waveform to obtain the corresponding target control waveform; then, at a later node, such as after completing multiple switching cycles of switching control, the phase shift angle step size is used to... The current phase shift angle is accumulated to obtain a new current phase shift angle (at this point, the current phase shift angle is 2). The initial control waveform is phase-shifted to obtain a new target control waveform... This process is repeated continuously.

[0047] For the second DC-DC converter circuit, the phase shift step size is first adjusted. 2 is used as the current phase shift angle, and the initial control waveform is phase-shifted to obtain the corresponding target control waveform; then at a subsequent node, based on the phase shift angle step size... 2. Accumulate the current phase shift angles to obtain a new current phase shift angle (the current phase shift angle at this point is 2). The initial control waveform is phase-shifted to obtain a new target control waveform... This process is repeated continuously.

[0048] By updating the current phase shift angle through continuous accumulation, the phase shift of the initial control waveform can reach exactly one full circle (360°) or approximately one full circle, thereby achieving a complete or near-complete reset of the initial control waveform. The current phase shift angle starts from... or The accumulation is performed, and when it reaches exactly one cycle or about one cycle, it is considered a phase shift cycle, thus achieving average power balance within one phase shift cycle.

[0049] In one embodiment, determining the phase shift step size of another DC-DC converter circuit based on the current difference between the output current and the average current of the DC-DC converter circuit includes: The number of divisions is determined based on the current difference between the output current and the average current of the DC-DC converter circuit.

[0050] As mentioned above, the larger the current difference, the larger the phase shift angle step size. In this embodiment, the number of divisions is used to divide the circumference in the subsequent process. Therefore, the larger the current difference, the fewer the number of divisions.

[0051] Based on this division number, the circumference is divided equally to obtain the phase shift angle step size of another DC-DC converter circuit.

[0052] For the first DC-DC converter circuit, once the corresponding number of divisions N1 is determined, the phase shift angle step size of the second DC-DC converter circuit is determined. 2 = circle angle / N1; For the second DC-DC converter circuit, determine the corresponding division number N2, at which point the phase shift angle step size of the first DC-DC converter circuit is... 1 = full circle / N2.

[0053] This embodiment divides the circumference into segments by determining the number of segments and obtains the corresponding phase shift angle step size. This ensures that after accumulating the phase shift angle step size, exactly one circumference is reached, thus improving the average power equalization effect.

[0054] In one embodiment, the number of divisions is determined based on the current difference between the output current and the average current of the DC-DC converter circuit, including: The corresponding phase shift period is determined based on the current difference between the output current and the average current of the DC-DC converter circuit.

[0055] As mentioned above, the larger the current difference, the larger the phase shift angle step size, and the fewer the number of divisions. Subsequently, the number of divisions is determined by the ratio of the phase shift change period to the switching period corresponding to the reference waveform parameters. Since the switching period is fixed, the smaller the phase shift change period, the fewer the number of divisions.

[0056] The number of divisions is obtained based on the ratio of the phase shift period to the switching period corresponding to the reference waveform parameters.

[0057] Wherein, the switching period is TA. For the first DC-DC converter circuit, the corresponding phase shift conversion period T1 is determined, and the corresponding number of divisions N1 = T1 / TA. The phase shift angle step size of the second DC-DC converter circuit is... 2 = cycle angle / N1; For the second DC-DC converter circuit, the corresponding phase shift conversion period T2 is determined, and the corresponding number of divisions N2 = T2 / TA, and the phase shift angle step size of the first DC-DC converter circuit. 1 = full circle / N2.

[0058] This embodiment combines the switching cycle to divide the cycle and obtain the corresponding phase shift angle step size, so that when controlling the switching of the DC-DC converter circuit, the current phase shift angle can be accumulated arbitrarily according to the switching cycle.

[0059] In one embodiment, based on the phase shift step size of the DC-DC converter circuit, the current phase shift angle of the DC-DC converter circuit is accumulated to obtain a new current phase shift angle of the DC-DC converter circuit, including: After completing the switching control of the DC-DC converter circuit for one switching cycle, the current phase shift angle of the DC-DC converter circuit is accumulated according to the phase shift angle step size of the DC-DC converter circuit to obtain the new current phase shift angle of the DC-DC converter circuit.

[0060] Since the phase shift angle step size corresponds to the switching cycle, the current phase shift angle can be accumulated once after each switching control cycle is completed.

[0061] In one embodiment, determining the average current among the output currents includes: Determine the current difference between each output current.

[0062] The larger the current difference between the output currents I1 and I2, the higher the power imbalance between the two DC-DC converter circuits; conversely, the smaller the current difference between the output currents I1 and I2, the lower the power imbalance between the two DC-DC converter circuits.

[0063] If the current difference between each output current exceeds the preset current difference, then the average current between each output current is determined.

[0064] The preset current difference is used to determine whether current sharing control is needed. If the current difference between the output current I1 and the output current I2 exceeds the preset current difference, it means that current sharing control is needed and the average current Iavg needs to be determined to achieve the subsequent current sharing process. Conversely, if the current difference between the output current I1 and the output current I2 does not exceed the preset current difference, it means that current sharing control is not needed and the average current Iavg does not need to be determined.

[0065] To make the above embodiments clearer, some or all of the above embodiments will now be described in combination, such as... Figure 4 As shown, the power supply control method includes: Obtain the output current I1, output current I2, and common output voltage Vbus; The common output voltage Vbus and the reference output voltage Vref are subjected to PI calculation to obtain the reference waveform parameters, which characterize carrier 1 and carrier 2 with the same switching frequency fa; Determine the average current Iavg between the output currents I1 and I2; Performing a PI calculation on the output current I1 and the average current Iavg yields the phase shift frequency f1. Based on the ratio of the switching frequency fa to the phase shift frequency f1, the phase shift angle step size is obtained. The phase-shifting parameters are used to characterize the sawtooth wave 2 used to achieve the phase shift, which is based on the phase-shifting angle step size. The phase shift frequency f2 is obtained by accumulating the currents; the phase shift frequency f2 is obtained by performing a PI calculation on the output current I2 and the average current Iavg. Based on the ratio of the switching frequency fa to the phase shift frequency f2, the phase shift angle step size is obtained. The phase-shifting parameters are used to characterize the sawtooth wave 1 used to achieve the phase shift, which is based on the phase-shifting angle step size. It changes through accumulation; Carrier 2 and sawtooth wave 2 are superimposed to obtain the corresponding target waveform parameters, which are used to control the PFM waveform generator to generate the corresponding target PFM waveform; carrier 1 and sawtooth wave 1 are superimposed to obtain the corresponding target waveform parameters, which are used to control the PFM waveform generator to generate the corresponding target PFM waveform. The switching transistors in each DC-DC converter circuit are controlled based on multiple target PFM waveforms.

[0066] Secondly, such as Figure 1 As shown, in one embodiment, the present invention provides a power supply control device, which includes a control circuit and a plurality of DC-DC converter circuits connected in parallel. The control circuit is electrically connected to each DC-DC converter circuit. The control circuit is used to implement the power supply control method in any of the above embodiments.

[0067] The power supply control method implemented by the aforementioned power supply control device obtains the common output voltage of multiple DC-DC converter circuits and the output current of each DC-DC converter circuit. On the one hand, it determines the reference waveform parameters based on the voltage difference between the common output voltage and the reference output voltage. On the other hand, it determines the phase shift parameters of each DC-DC converter circuit based on the average current between each output current. Thus, based on the phase shift parameters and the reference waveform parameters, it determines the target waveform parameters of each DC-DC converter circuit. Then, it controls the switching of each DC-DC converter circuit based on the target waveform parameters. First, different phase shift parameters are obtained based on the differences between the output currents, thereby achieving different degrees of phase shifting in each DC-DC converter circuit, and thus achieving current sharing among the DC-DC converter circuits. Second, the common output voltage is only used to achieve voltage regulation, and each output current is only used to achieve phase shifting and current sharing, so that voltage regulation and phase shifting and current sharing are independent and do not affect each other, thereby further improving the current sharing effect.

[0068] like Figure 5 As shown, in one embodiment, the DC-DC converter circuit includes a three-phase star LLC resonant converter.

[0069] Among them, the three-phase star LLC is an isolated DC-DC topology for high-power scenarios. The primary side adopts three sets of symmetrical half-bridge inverters. The resonant inductor, resonant capacitor and high-frequency transformer are connected in a star configuration to form a three-phase independent resonant branch. The secondary transformer windings are mostly star-connected, and then connected to a three-phase rectified DC output.

[0070] Specifically, such as Figure 6 As shown, the first three-phase star-connected LLC resonant converter consists of switching transistors Q1, Q2, Q3, Q4, Q5, and Q6; resonant inductors L1, L2, L3, L4, L5, and L6; resonant capacitors C1, C2, and C3; transformers TL1, TL2, and TL3; and rectifier diodes D1, D2, D3, D4, D5, and D6. It is used to achieve DC-DC conversion between the DC power supply Vbat and the DC load Ro. Similarly, the second... Two three-phase star-connected LLC resonant converters consist of switching transistors Q7, Q8, Q9, Q10, Q11, and Q12; resonant inductors L7, L8, L9, L10, L11, and L12; resonant capacitors C4, C5, and C6; transformers TL4, TL5, and TL6; and rectifier diodes D7, D8, D9, D10, D11, and D12. These converters are used to achieve DC-DC conversion between the DC power supply Vbat and the DC load Ro.

[0071] Thirdly, such as Figure 1 As shown, in one embodiment, the present invention provides an electrical system, which includes a DC power supply, a DC load, and a power supply control device as described in any of the above embodiments; The input terminal of each DC-DC converter circuit is electrically connected to a DC power supply, and the output terminal of each DC-DC converter circuit is electrically connected to a DC load.

[0072] The power supply control method implemented through the above electrical system obtains the common output voltage of multiple DC-DC converter circuits and the output current of each DC-DC converter circuit. On the one hand, the reference waveform parameters are determined based on the voltage difference between the common output voltage and the reference output voltage. On the other hand, the phase shift parameters of each DC-DC converter circuit are determined based on the average current between each output current. Thus, the target waveform parameters of each DC-DC converter circuit are determined based on the phase shift parameters and the reference waveform parameters. Then, the switching control of each DC-DC converter circuit is performed based on the target waveform parameters. First, different phase shift parameters are obtained based on the differences between the output currents, thereby achieving different degrees of phase shifting in each DC-DC converter circuit, and thus achieving current sharing among the DC-DC converter circuits. Second, the common output voltage is only used to achieve voltage regulation, and each output current is only used to achieve phase shifting and current sharing, so that voltage regulation and phase shifting and current sharing are independent and do not affect each other, thereby further improving the current sharing effect.

[0073] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the detailed descriptions of other embodiments above, which will not be repeated here.

[0074] The above provides a detailed description of the power supply control method, power supply control device, and electrical system provided by the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

[0075] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A power supply control method, characterized in that, The power supply control device includes a control circuit and multiple DC-DC converter circuits connected in parallel, the control circuit being electrically connected to each of the DC-DC converter circuits; the power supply control method includes the following steps performed by the control circuit: Obtain the common output voltage of the multiple DC-DC converter circuits and the output current of each DC-DC converter circuit; The reference waveform parameters are determined based on the voltage difference between the common output voltage and the reference output voltage. Determine the average current between each of the output currents, and determine the phase shift parameters of each DC-DC converter circuit based on the current difference between each output current and the average current. Based on the phase shift parameters and the reference waveform parameters, the target waveform parameters of each DC-DC converter circuit are determined, and the switching control of each DC-DC converter circuit is performed using the target waveform parameters.

2. The power supply control method according to claim 1, characterized in that, The DC-DC converter circuit is provided in two configurations; the step of determining the phase shift parameter of each DC-DC converter circuit based on the current difference between each output current and the average current includes: For each DC-DC converter circuit, the phase shift parameters of another DC-DC converter circuit are determined based on the current difference between the output current of the DC-DC converter circuit and the average current.

3. The power supply control method according to claim 2, characterized in that, Determining the phase shift parameters of another DC-DC converter circuit based on the current difference between the output current of the DC-DC converter circuit and the average current includes: The phase shift step size of another DC-DC converter circuit is determined based on the current difference between the output current of the DC-DC converter circuit and the average current; the larger the current difference between the output current of the DC-DC converter circuit and the average current, the larger the phase shift step size of the other DC-DC converter circuit; the phase shift parameter includes the phase shift step size. The step of determining the target waveform parameters for each DC-DC converter circuit based on the phase shift parameters and the reference waveform parameters, and then controlling the switching of each DC-DC converter circuit using the target waveform parameters, includes: For each DC-DC converter circuit: The phase shift angle step size of the DC-DC converter circuit is used as the current phase shift angle of the DC-DC converter circuit. Based on the current phase shift angle of the DC-DC converter circuit, the reference waveform parameters are phase shifted to obtain the target waveform parameters of the DC-DC converter circuit. The DC-DC converter circuit is then switched on and off using the target waveform parameters of the DC-DC converter circuit. Based on the phase shift step size of the DC-DC converter circuit, the current phase shift angle of the DC-DC converter circuit is accumulated to obtain a new current phase shift angle of the DC-DC converter circuit. Based on the new current phase shift angle of the DC-DC converter circuit, the reference waveform parameters are phase-shifted to obtain new target waveform parameters of the DC-DC converter circuit. The DC-DC converter circuit is then switched on and off using the new target waveform parameters of the DC-DC converter circuit.

4. The power supply control method according to claim 3, characterized in that, The step of determining the phase shift angle step of another DC-DC converter circuit based on the current difference between the output current of the DC-DC converter circuit and the average current includes: The number of divisions is determined based on the current difference between the output current of the DC-DC converter circuit and the average current. Based on this division number, the circumference is divided equally to obtain the phase shift angle step size of another DC-DC converter circuit.

5. The power supply control method according to claim 4, characterized in that, The step of determining the corresponding number of divisions based on the current difference between the output current of the DC-DC converter circuit and the average current includes: The corresponding phase shift period is determined based on the current difference between the output current of the DC-DC converter circuit and the average current. The number of divisions is obtained based on the ratio of the phase shift period to the switching period corresponding to the reference waveform parameters.

6. The power supply control method according to claim 5, characterized in that, The step of accumulating the current phase shift angle of the DC-DC converter circuit according to the phase shift angle step size to obtain the new current phase shift angle of the DC-DC converter circuit includes: After completing the switching control of the DC-DC converter circuit for one switching cycle, the current phase shift angle of the DC-DC converter circuit is accumulated according to the phase shift angle step size of the DC-DC converter circuit to obtain the new current phase shift angle of the DC-DC converter circuit.

7. The power supply control method according to claim 2, characterized in that, Determining the average current among the output currents includes: Determine the current difference between each of the output currents; If the current difference between each of the output currents exceeds a preset current difference, then the average current between each of the output currents is determined.

8. A power supply control device, characterized in that, The power supply control device includes a control circuit and multiple DC-DC converter circuits connected in parallel, wherein the control circuit is electrically connected to each of the DC-DC converter circuits; the control circuit is used to implement the power supply control method according to any one of claims 1 to 7.

9. The power supply control device according to claim 8, characterized in that, The DC-DC converter circuit includes a three-phase star LLC resonant converter.

10. An electrical system, characterized in that, The electrical system includes a DC power supply, a DC load, and the power supply control device as described in claim 8 or 9; The input terminal of each DC-DC converter circuit is electrically connected to the DC power supply, and the output terminal of each DC-DC converter circuit is electrically connected to the DC load.

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