Power supply control device, current sharing control method, and electrical system

Abstract

This invention provides a power supply control device, a current sharing control method, and an electrical system. The power supply control device includes multiple DC-DC converter circuits connected in parallel. For each DC-DC converter circuit, the circuit includes a negative adjustment module and a positive adjustment module. The input terminal of the negative adjustment module is electrically connected to a DC power supply, and its output terminal is electrically connected to the input terminal of the positive adjustment module. The output terminal of the positive adjustment module is electrically connected to a DC bus. The negative adjustment module regulates the negative output current of the DC-DC converter circuit, and the positive adjustment module regulates the positive output current of the DC-DC converter circuit. This invention enables the formation of independent positive and negative power transmission paths within the DC-DC converter circuits, thereby blocking internal circulating currents between modules at the physical structure level. This effectively reduces the difference in output current between the DC-DC converter circuits, ultimately reducing the difficulty of current sharing among them.

Description

Technical Field

[0001] This invention relates to the field of power supply technology, specifically to a power supply control device, a current sharing control method, 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 results in a significant difference between their output DC current and the output current of other DC-DC converter circuits, ultimately increasing the difficulty of current sharing among the various DC-DC converter circuits. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a power supply control device, a current sharing control method, and an electrical system.

[0005] In one embodiment, the present invention provides a power supply control device, which includes a plurality of DC-DC converter circuits connected in parallel. For each DC-DC converter circuit, the DC-DC converter circuit includes a negative adjustment module and a positive adjustment module. The input terminal of the negative adjustment module is used to be electrically connected to the DC power supply, the output terminal of the negative adjustment module is electrically connected to the input terminal of the positive adjustment module, and the output terminal of the positive adjustment module is used to be electrically connected to the DC bus. The negative adjustment module is used to adjust the negative output current of the DC-DC converter circuit, and the positive adjustment module is used to adjust the positive output current of the DC-DC converter circuit.

[0006] In one embodiment, the negative electrode adjustment module includes a negative electrode adjustment unit and a negative electrode output capacitor, and the positive electrode adjustment module includes a positive electrode adjustment unit and a positive electrode output capacitor. The input terminal of the negative adjustment unit is used to connect to the DC power supply. The output terminal of the negative adjustment unit is connected to the input terminal of the positive adjustment unit through the negative output capacitor. The output terminal of the positive adjustment unit is used to connect to the DC bus through the positive output capacitor.

[0007] In one embodiment, the negative electrode adjustment unit includes a negative electrode buck chopper topology subunit composed of a first energy storage inductor, a first power switch and a first freewheeling diode, and the positive electrode adjustment unit includes a positive electrode boost chopper topology subunit composed of a second energy storage inductor, a second power switch and a second freewheeling diode.

[0008] In one embodiment, the input terminal of the first power switch is electrically connected to the first terminal of the negative output capacitor and the input terminal of the second power switch, respectively, and is used to connect to the positive terminal of the DC power supply. The output terminal of the first power switch is electrically connected to the second terminal of the first energy storage inductor and the cathode of the first freewheeling diode, respectively. The first terminal of the first energy storage inductor is used to connect to the negative terminal of the DC power supply. The anode of the first freewheeling diode is electrically connected to the second terminal of the negative output capacitor, the anode of the second freewheeling diode, and the second terminal of the positive output capacitor, respectively, and is used to connect to the negative terminal of the DC bus. The output terminal of the second power switch is electrically connected to the first terminal of the second energy storage inductor and the cathode of the second freewheeling diode, respectively. The second terminal of the second energy storage inductor is electrically connected to the first terminal of the positive output capacitor and is used to connect to the positive terminal of the DC bus.

[0009] In one embodiment, the negative electrode adjustment unit includes a negative electrode boost chopper topology subunit composed of a third energy storage inductor, a third power switch and a third freewheeling diode, and the positive electrode adjustment unit includes a positive electrode buck chopper topology subunit composed of a fourth energy storage inductor, a fourth power switch and a fourth freewheeling diode.

[0010] In one embodiment, the cathode of the third freewheeling diode is electrically connected to the first terminal of the negative output capacitor and the first terminal of the fourth energy storage inductor, respectively, and is used to connect to the positive terminal of the DC power supply. The anode of the third freewheeling diode is electrically connected to the output terminal of the third power switch and the first terminal of the third energy storage inductor, respectively. The input terminal of the third power switch is used to connect to the negative terminal of the DC power supply. The second terminal of the third energy storage inductor is electrically connected to the second terminal of the negative output capacitor, the output terminal of the fourth power switch, and the second terminal of the positive output capacitor, respectively, and is used to connect to the negative terminal of the DC bus. The second terminal of the fourth energy storage inductor is electrically connected to the input terminal of the fourth power switch and the anode of the fourth freewheeling diode, respectively. The cathode of the fourth freewheeling diode is electrically connected to the first terminal of the positive output capacitor and is used to connect to the positive terminal of the DC bus.

[0011] In one embodiment, the negative electrode adjustment module includes a plurality of negative electrode adjustment units connected in parallel, and / or, the positive electrode adjustment module includes a plurality of positive electrode adjustment units connected in parallel.

[0012] Secondly, in one embodiment, the present invention provides a current sharing control method applied to the power supply control device in any of the above embodiments; for each DC-DC converter circuit, the current sharing control method includes: Obtain the negative reference impedance, positive reference impedance, initial negative reference voltage, initial positive reference voltage, negative output current of the DC-DC converter circuit, and positive output current of the DC-DC converter circuit. Based on the positive reference impedance, the initial positive reference voltage, and the positive output current of the DC-DC converter circuit, the initial positive reference voltage is corrected to obtain the corrected positive reference voltage. Voltage loop control is then performed based on the corrected positive reference voltage to adjust the positive output current of the DC-DC converter circuit. Based on the negative reference impedance, the initial negative reference voltage, and the negative output current of the DC-DC converter circuit, the initial negative reference voltage is corrected to obtain the corrected negative reference voltage. Voltage loop control is then performed based on the corrected negative reference voltage to adjust the negative output current of the DC-DC converter circuit.

[0013] In one embodiment, the initial positive reference voltage is corrected based on the positive reference impedance, the initial positive reference voltage, and the positive output current of the DC-DC converter circuit to obtain a corrected positive reference voltage, including: Determine the first product of the positive output current and the positive reference impedance of the DC-DC converter circuit; Determine the first difference between the initial positive reference voltage and the first product value; The first difference is used as the corrected positive reference voltage.

[0014] In one embodiment, the initial negative reference voltage is corrected based on the negative reference impedance, the initial negative reference voltage, and the negative output current of the DC-DC converter circuit to obtain a corrected negative reference voltage, including: Determine the second product of the negative output current and the negative reference impedance of the DC-DC converter circuit; Determine the second difference between the initial negative reference voltage and the second product value; The second difference is used as the corrected negative reference voltage.

[0015] Thirdly, in one embodiment, the present invention provides a current sharing control method applied to the power supply control device in any of the above embodiments; for each DC-DC converter circuit, the current sharing control method includes: Obtain the negative output current of the DC-DC converter circuit, the positive output current of the DC-DC converter circuit, the negative output current of other DC-DC converter circuits, and the positive output current of other DC-DC converter circuits. Determine the negative output current of this DC-DC converter circuit and the average negative current of the negative output current of other DC-DC converter circuits, and adjust the negative output current of this DC-DC converter circuit according to the average negative current. Determine the positive output current of this DC-DC converter circuit and the average positive current of the positive output current of other DC-DC converter circuits, and adjust the positive output current of this DC-DC converter circuit according to the average positive current.

[0016] Fourthly, in one embodiment, the present invention provides an electrical system including a DC power supply, a DC bus, a DC load, and a power supply control device as described in any of the above embodiments; The DC load is electrically connected to the DC bus.

[0017] By using the aforementioned power supply control device, current sharing control method, and electrical system, a negative adjustment module for adjusting the negative output current and a positive adjustment module for adjusting the positive output current are sequentially set up. This enables the formation of independent positive and negative power transmission paths in the DC-DC converter circuit, thereby blocking the internal circulating current between modules at the physical structure level. This effectively reduces the difference in output current between each DC-DC converter circuit, ultimately reducing the difficulty of current sharing between each DC-DC converter circuit. Attached Figure Description

[0018] 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.

[0019] 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 schematic diagram of the specific components of the power supply control device including the adjustment module in one embodiment of the present invention; Figure 3 This is a schematic diagram of the adjustment unit in one embodiment of the present invention; Figure 4 This is a schematic diagram of the specific circuit of the adjustment unit in another embodiment of the present invention; Figure 5 This is a schematic diagram of a structure in one embodiment of the present invention, showing that the adjustment unit has multiple units; Figure 6 This is a schematic diagram of a specific circuit of multiple adjustment units in one embodiment of the present invention; Figure 7This is a schematic diagram of the specific circuit of multiple adjustment units in another embodiment of the present invention; Figure 8 This is a schematic diagram of the electrical system in one embodiment of the present invention. Detailed Implementation

[0020] 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.

[0021] 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.

[0022] Firstly, such as Figure 1 As shown, in one embodiment, the present invention provides a power supply control device, which includes multiple DC-DC converter circuits connected in parallel.

[0023] in, Figure 1Only two DC-DC converter circuits are shown in parallel. In other embodiments, more DC-DC converter circuits can be connected in parallel.

[0024] For each DC-DC converter circuit, the DC-DC converter circuit includes a negative adjustment module and a positive adjustment module. The input terminal of the negative adjustment module is used to be electrically connected to the DC power supply, the output terminal of the negative adjustment module is electrically connected to the input terminal of the positive adjustment module, and the output terminal of the positive adjustment module is used to be electrically connected to the DC bus.

[0025] The negative adjustment module is used to adjust the negative output current of the DC-DC converter circuit (such as the negative output current In1 of the first DC-DC converter circuit or the negative output current In2 of the second DC-DC converter circuit), and the positive adjustment module is used to adjust the positive output current of the DC-DC converter circuit (such as the positive output current Ip1 of the first DC-DC converter circuit or the positive output current Ip2 of the second DC-DC converter circuit).

[0026] The negative electrode adjustment module, configured to regulate the negative output current of the DC-DC converter circuit, has its main power devices located on the negative branch. Similarly, the positive electrode adjustment module, configured to regulate the positive output current of the DC-DC converter circuit, has its main power devices located on the positive branch. These main power devices include energy storage inductors, power switching transistors, and / or freewheeling diodes.

[0027] Specifically, since the negative adjustment module, which has the main power devices set on the negative branch, is configured between the DC power supply and the positive adjustment module, the power transmission between the input terminals of the DC power supply and the positive adjustment module is not affected by other power devices. Furthermore, the output terminal of the positive adjustment module is directly connected to the DC bus, thus forming independent positive power transmission paths between the DC power supply and the DC bus.

[0028] Similarly, since the main power devices are located on the positive branch, the positive regulation module is configured between the negative regulation module and the DC bus, so that the power transmission between the output end of the negative regulation module and the DC bus is not affected by other power devices. Furthermore, the input end of the negative regulation module is directly connected to the DC power supply, thus forming independent negative power transmission paths between the DC power supply and the DC bus.

[0029] By using the aforementioned power supply control device, a negative adjustment module for adjusting the negative output current and a positive adjustment module for adjusting the positive output current are sequentially set up. This enables the formation of independent positive and negative power transmission paths in the DC-DC converter circuit, thereby blocking the internal circulating current between modules at the physical structure level. This effectively reduces the difference in output current between each DC-DC converter circuit, and ultimately reduces the difficulty of current sharing between each DC-DC converter circuit.

[0030] like Figure 2 As shown, in one embodiment, the negative electrode adjustment module includes a negative electrode adjustment unit and a negative electrode output capacitor C1, and the positive electrode adjustment module includes a positive electrode adjustment unit and a positive electrode output capacitor C2.

[0031] The input terminal of the negative adjustment unit is used to connect to the DC power supply. The output terminal of the negative adjustment unit is connected to the input terminal of the positive adjustment unit through the negative output capacitor C1. The output terminal of the positive adjustment unit is used to connect to the DC bus through the positive output capacitor C2.

[0032] The negative output capacitor C1 is used to achieve output filtering, voltage regulation and transient support of the negative regulation unit; similarly, the positive output capacitor C2 is used to achieve output filtering, voltage regulation and transient support of the positive regulation unit.

[0033] like Figure 3 As shown, in one embodiment, the negative electrode adjustment unit includes a negative electrode buck chopper subunit composed of a first energy storage inductor L1, a first power switch Q1 and a first freewheeling diode D1, and the positive electrode adjustment unit includes a positive electrode boost chopper topology subunit composed of a second energy storage inductor L2, a second power switch Q2 and a second freewheeling diode D2.

[0034] Specifically, the input terminal of the first power switch Q1 is electrically connected to the first terminal of the negative output capacitor C1 and the input terminal of the second power switch Q2, and is used to connect to the positive terminal VIN+ of the DC power supply. The output terminal of the first power switch Q1 is electrically connected to the second terminal of the first energy storage inductor L1 and the cathode of the first freewheeling diode D1. The first terminal of the first energy storage inductor L1 is used to connect to the negative terminal VIN- of the DC power supply. The anode of the first freewheeling diode D1 is electrically connected to the second terminal of the negative output capacitor C1, the anode of the second freewheeling diode D2, and the second terminal of the positive output capacitor C2, and is used to connect to the negative terminal VOUT- of the DC bus. The output terminal of the second power switch Q2 is electrically connected to the first terminal of the second energy storage inductor L2 and the cathode of the second freewheeling diode D2. The second terminal of the second energy storage inductor L2 is electrically connected to the first terminal of the positive output capacitor C2 and is used to connect to the positive terminal VOUT+ of the DC bus.

[0035] For the negative electrode adjustment unit: During the on-phase of the first power switch Q1, the current output from the positive terminal VIN+ of the DC power supply returns to the negative terminal VIN- of the DC power supply after passing through the first power switch Q1 and the first energy storage inductor L1, at which time the first energy storage inductor L1 stores energy; During the off-phase of the first power switch Q1, the first energy storage inductor L1 freewheels through the first freewheeling diode D1, and the current flows in from the negative terminal VOUT- of the DC bus, at which time the first energy storage inductor L1 releases energy; During this process, the average current on the first energy storage inductor L1 can be controlled by adjusting the on-phase duty cycle of the first power switch Q1, thereby realizing the adjustment of the negative electrode output current.

[0036] For the positive electrode regulation unit: During the on-state of the second power switch Q2, the current output from the first terminal of the negative electrode output capacitor C1 passes through the second power switch Q2 and the second energy storage inductor, and is then output to the positive terminal VOUT+ of the DC bus through the positive electrode output capacitor C2. At this time, the second energy storage inductor L2 stores energy. During the off-state of the second power switch Q2, the second energy storage inductor L2 freewheels through the second freewheeling diode D2, and the current is output to the positive terminal VOUT+ of the DC bus. At this time, the second energy storage inductor L2 releases energy. During this process, the average current on the second energy storage inductor L2 can be controlled by adjusting the on-state duty cycle of the second power switch Q2, thereby achieving the regulation of the positive electrode output current.

[0037] like Figure 4 As shown, in one embodiment, the negative electrode adjustment unit includes a negative electrode boost chopper topology subunit composed of a third energy storage inductor L3, a third power switch Q3 and a third freewheeling diode D3, and the positive electrode adjustment unit includes a positive electrode buck chopper topology subunit composed of a fourth energy storage inductor L4, a fourth power switch Q4 and a fourth freewheeling diode D4.

[0038] Specifically, the cathode of the third freewheeling diode D3 is electrically connected to the first terminal of the negative output capacitor C1 and the first terminal of the fourth energy storage inductor L4, and is used to connect to the positive terminal VIN+ of the DC power supply. The anode of the third freewheeling diode D3 is electrically connected to the output terminal of the third power switch Q3 and the first terminal of the third energy storage inductor L3. The input terminal of the third power switch Q3 is used to connect to the negative terminal VIN- of the DC power supply. The second terminal of the third energy storage inductor L3 is electrically connected to the second terminal of the negative output capacitor C1, the output terminal of the fourth power switch Q4, and the second terminal of the positive output capacitor C2, and is used to connect to the negative terminal VOUT- of the DC bus. The second terminal of the fourth energy storage inductor L4 is electrically connected to the input terminal of the fourth power switch Q4 and the anode of the fourth freewheeling diode D4. The cathode of the fourth freewheeling diode D4 is electrically connected to the first terminal of the positive output capacitor C2 and is used to connect to the positive terminal VOUT+ of the DC bus.

[0039] For the negative electrode regulation unit: During the conduction phase of the third power switch Q3, the current connected to the negative terminal VOUT- of the DC bus returns to the negative terminal VIN- of the DC power supply after passing through the third energy storage inductor L3 and the third power switch Q3, at which time the third energy storage inductor L3 stores energy; During the turn-off phase of the third power switch Q3, the third energy storage inductor L3 freewheels through the third freewheeling diode D3, and the current flows in from the negative terminal VOUT- of the DC bus, at which time the third energy storage inductor L3 releases energy; During this process, the average current on the third energy storage inductor L3 can be controlled by adjusting the conduction duty cycle of the third power switch Q3, thereby realizing the regulation of the negative electrode output current.

[0040] For the positive electrode regulation unit: During the on-state of the fourth power switch Q4, the current connected to the first terminal of the negative output capacitor C1 returns to the second terminal of the negative output capacitor C1 after passing through the fourth energy storage inductor L4 and the fourth power switch Q4, at which time the fourth energy storage inductor L4 stores energy; During the off-state of the fourth power switch Q4, the fourth energy storage inductor L4 freewheels through the fourth freewheeling diode D4, and the current is output to the positive terminal VOUT+ of the DC bus, at which time the fourth energy storage inductor L4 releases energy; During this process, the average current on the fourth energy storage inductor L4 can be controlled by adjusting the on-state duty cycle of the fourth power switch Q4, thereby realizing the regulation of the positive electrode output current.

[0041] Understandable, Figure 3 and Figure 4 Different DC-DC architectures are shown to implement different buck-boost strategies.

[0042] like Figure 5 As shown, in one embodiment, the negative electrode adjustment module includes a plurality of negative electrode adjustment units arranged in parallel, and the positive electrode adjustment module includes a plurality of positive electrode adjustment units arranged in parallel.

[0043] In other embodiments, the negative electrode adjustment module may include multiple negative electrode adjustment units connected in parallel, or the positive electrode adjustment module may include multiple positive electrode adjustment units connected in parallel.

[0044] By connecting multiple regulating units in parallel, the output current waveform can be smoother and better suited to high current output scenarios. In addition, it can still maintain a certain regulating capability when some regulating units fail, thus improving the redundancy of the circuit.

[0045] like Figure 6As shown, in one embodiment, the negative electrode adjustment module specifically includes "a negative electrode adjustment unit composed of energy storage inductor L11, power switch Q11 and freewheeling diode D11", "a negative electrode adjustment unit composed of energy storage inductor L12, power switch Q12 and freewheeling diode D12", "a negative electrode adjustment unit composed of energy storage inductor L13, power switch Q13 and freewheeling diode D13", etc.; the positive electrode adjustment module specifically includes "a positive electrode adjustment unit composed of energy storage inductor L21, power switch Q21 and freewheeling diode D21", "a positive electrode adjustment unit composed of energy storage inductor L22, power switch Q22 and freewheeling diode D22", "a positive electrode adjustment unit composed of energy storage inductor L23, power switch Q23 and freewheeling diode D23", etc.

[0046] The connection relationship and working principle of each negative electrode regulating unit and each positive electrode regulating unit in this embodiment are as follows: Figure 3 The negative electrode adjustment unit shown is the same as the positive electrode adjustment unit, and will not be described again here.

[0047] like Figure 7 As shown, in one embodiment, the negative electrode adjustment module specifically includes "a negative electrode adjustment unit composed of energy storage inductor L31, power switch Q31 and freewheeling diode D31", "a negative electrode adjustment unit composed of energy storage inductor L32, power switch Q32 and freewheeling diode D32", "a negative electrode adjustment unit composed of energy storage inductor L33, power switch Q33 and freewheeling diode D33", etc.; the positive electrode adjustment module specifically includes "a positive electrode adjustment unit composed of energy storage inductor L41, power switch Q41 and freewheeling diode D41", "a positive electrode adjustment unit composed of energy storage inductor L42, power switch Q42 and freewheeling diode D42", "a positive electrode adjustment unit composed of energy storage inductor L43, power switch Q43 and freewheeling diode D43", etc.

[0048] The connection relationship and working principle of each negative electrode regulating unit and each positive electrode regulating unit in this embodiment are as follows: Figure 4 The negative electrode adjustment unit shown is the same as the positive electrode adjustment unit, and will not be described again here.

[0049] Secondly, in one embodiment, the present invention provides a current sharing control method applied to the power supply control device in any of the above embodiments.

[0050] The power supply control device in the above embodiments avoids internal circulating current in the DC-DC converter circuit by changing the circuit structure, thereby reducing the difference between output currents and simplifying current sharing. However, in practical applications, different DC-DC converter circuits have different impedances, resulting in different current outputs when connected to the same DC power supply, making current sharing impossible. Therefore, in this embodiment, a current sharing control method is used to further eliminate the influence of impedance, reliably achieving output current sharing for each DC-DC converter circuit.

[0051] Reference Figure 1 For each DC-DC converter circuit, the current sharing control methods include: The first DC-DC converter circuit acquires the negative reference impedance Rdn, the positive reference impedance Rdp, the initial negative reference voltage Vrefn, the initial positive reference voltage Vrefp, the negative output current In1 of the DC-DC converter circuit, and the positive output current Ip1 of the DC-DC converter circuit; the second DC-DC converter circuit acquires the negative reference impedance Rdn, the positive reference impedance Rdp, the initial negative reference voltage Vrefn, the initial positive reference voltage Vrefp, the negative output current In2 of the DC-DC converter circuit, and the positive output current Ip2 of the DC-DC converter circuit.

[0052] The negative reference impedance Rdn, positive reference impedance Rdp, initial negative reference voltage Vrefn, and initial positive reference voltage Vrefp obtained by each DC-DC converter circuit are consistent.

[0053] The first DC-DC converter circuit corrects the initial positive reference voltage Vrefp based on the positive reference impedance Rdp, the initial positive reference voltage Vrefp, and the positive output current Ip1 of the DC-DC converter circuit, obtaining a corrected positive reference voltage Vrefp1. Voltage loop control is performed based on the corrected positive reference voltage Vrefp1 to adjust the positive output current Ip1 of the DC-DC converter circuit. The second DC-DC converter circuit corrects the initial positive reference voltage Vrefp based on the positive reference impedance Rdp, the initial positive reference voltage Vrefp, and the positive output current Ip2 of the DC-DC converter circuit, obtaining a corrected positive reference voltage Vrefp2. Voltage loop control is performed based on the corrected positive reference voltage Vrefp2 to adjust the positive output current Ip2 of the DC-DC converter circuit.

[0054] When the positive output currents Ip1 and Ip2 are not equal, the corrected positive reference voltages Vrefp1 and Vrefp2 are different, thus achieving different voltage loop control, which causes the large current to flow to the small current, and finally achieves current sharing.

[0055] The first DC-DC converter circuit corrects the initial negative reference voltage Vrefn based on the negative reference impedance Rdn, the initial negative reference voltage Vrefn, and the negative output current In1 of the DC-DC converter circuit, obtaining a corrected negative reference voltage Vrefn1. Voltage loop control is performed based on the corrected negative reference voltage Vrefn1 to adjust the negative output current In1 of the DC-DC converter circuit. The second DC-DC converter circuit corrects the initial negative reference voltage Vrefn based on the negative reference impedance Rdn, the initial negative reference voltage Vrefn, and the negative output current In2 of the DC-DC converter circuit, obtaining a corrected negative reference voltage Vrefn2. Voltage loop control is performed based on the corrected negative reference voltage Vrefn2 to adjust the negative output current In2 of the DC-DC converter circuit.

[0056] When the negative output currents In1 and In2 are not equal, the corrected negative reference voltages Vrefn1 and Vrefn2 are different, thus achieving different voltage loop control, which causes the large current to flow to the small current, and finally achieves current equalization.

[0057] In this embodiment, each DC-DC converter circuit is based on the same negative reference impedance Rdn, positive reference impedance Rdp, initial negative reference voltage Vrefn, and initial positive reference voltage Vrefp. The DC-DC converter circuits do not need to communicate with each other, which simplifies the circuit wiring.

[0058] In one embodiment, taking the first DC-DC converter circuit as an example, the initial positive reference voltage Vrefp is corrected based on the positive reference impedance Rdp, the initial positive reference voltage Vrefp, and the positive output current Ip1 of the DC-DC converter circuit, to obtain the corrected positive reference voltage Vrefp1, including: Determine the first product of the positive output current Ip1 and the positive reference impedance Rdp of the DC-DC converter circuit.

[0059] The first product value is Ip1×Rdp.

[0060] Determine the first difference between the initial positive reference voltage Vrefp and the first product value.

[0061] The first difference is Vrefp-Ip1×Rdp.

[0062] The first difference is used as the corrected positive reference voltage Vrefp1.

[0063] Among them, the corrected positive reference voltage Vrefp1 = Vrefp - Ip1 × Rdp.

[0064] In this embodiment, if Ip1 is greater than Ip2, then the corrected positive reference voltage Vrefp1 is less than the corrected positive reference voltage Vrefp2. During voltage loop control, the current will automatically flow from the first DC-DC converter circuit to the second DC-DC converter circuit. At this time, Ip1 decreases and Ip2 increases, eventually becoming consistent, thus achieving current sharing.

[0065] In one embodiment, taking the first DC-DC converter circuit as an example, the initial negative reference voltage Vrefn is corrected based on the negative reference impedance Rdn, the initial negative reference voltage Vrefn, and the negative output current In1 of the DC-DC converter circuit, to obtain the corrected negative reference voltage Vrefn1, including: Determine the second product of the negative output current In1 and the negative reference impedance Rdn of the DC-DC converter circuit.

[0066] The second product value is In1×Rdn.

[0067] Determine the second difference between the initial negative reference voltage Vrefn and the second product value.

[0068] The second difference is Vrefn-In1×Rdn.

[0069] The second difference is used as the corrected negative reference voltage Vrefn1.

[0070] Among them, the corrected negative reference voltage Vrefn1 is Vrefn-In1×Rdn.

[0071] In this embodiment, if In1 is greater than In2, then the corrected negative reference voltage Vrefn1 is less than the corrected negative reference voltage Vrefn2. During voltage loop control, the current will automatically flow from the first DC-DC converter circuit to the second DC-DC converter circuit. At this time, In1 decreases and In2 increases, eventually becoming consistent, thus achieving current sharing.

[0072] Thirdly, in one embodiment, the present invention provides a current sharing control method applied to the power supply control device in any of the above embodiments; for each DC-DC converter circuit, the current sharing control method includes: The first DC-DC converter circuit obtains the negative output current In1 of the DC-DC converter circuit, the positive output current Ip1 of the DC-DC converter circuit, the negative output current of other DC-DC converter circuits (such as the negative output current In2 of the second DC-DC converter circuit), and the positive output current of other DC-DC converter circuits (such as the positive output current Ip2 of the second DC-DC converter circuit).

[0073] The first DC-DC converter circuit determines the negative output current In1 of the DC-DC converter circuit and the average negative current Inavg of the negative output current In2 of the other DC-DC converter circuits, and adjusts the negative output current In1 of the DC-DC converter circuit according to the average negative current Inavg.

[0074] The first DC-DC converter circuit determines the positive output current Ip1 of the DC-DC converter circuit and the average positive current Ipavg of the positive output current Ip2 of other DC-DC converter circuits, and adjusts the positive output current Ip1 of the DC-DC converter circuit according to the average positive current Ipavg.

[0075] This embodiment is based on the premise that each DC-DC converter circuit can communicate, and the current sharing adjustment is directly performed according to the average current of each output current.

[0076] Fourthly, such as Figure 8 As shown, in one embodiment, the present invention provides an electrical system, which includes a DC power supply, a DC bus, a DC load, and a power supply control device as described in any of the above embodiments; The DC load is electrically connected to the DC bus.

[0077] By using the power supply control device included in the aforementioned electrical system, a negative adjustment module for adjusting the negative output current and a positive adjustment module for adjusting the positive output current are sequentially set up. This enables the formation of independent positive and negative power transmission paths in the DC-DC converter circuit, thereby blocking the internal circulating current between modules at the physical structure level. This effectively reduces the difference in output current between each DC-DC converter circuit, and ultimately reduces the difficulty of current sharing between each DC-DC converter circuit.

[0078] 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.

[0079] The power supply control device, current sharing control method, and electrical system provided by the present invention have been described in detail above. 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.

[0080] 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 device, characterized in that, The power supply control device includes multiple DC-DC converter circuits connected in parallel; For each of the DC-DC converter circuits, the DC-DC converter circuit includes a negative adjustment module and a positive adjustment module. The input terminal of the negative adjustment module is used to be electrically connected to a DC power supply, the output terminal of the negative adjustment module is electrically connected to the input terminal of the positive adjustment module, and the output terminal of the positive adjustment module is used to be electrically connected to a DC bus. The negative electrode adjustment module is used to adjust the negative electrode output current of the DC-DC converter circuit, and the positive electrode adjustment module is used to adjust the positive electrode output current of the DC-DC converter circuit.

2. The power supply control device according to claim 1, characterized in that, The negative electrode adjustment module includes a negative electrode adjustment unit and a negative electrode output capacitor, and the positive electrode adjustment module includes a positive electrode adjustment unit and a positive electrode output capacitor; The input terminal of the negative adjustment unit is used to be electrically connected to the DC power supply, the output terminal of the negative adjustment unit is electrically connected to the input terminal of the positive adjustment unit through the negative output capacitor, and the output terminal of the positive adjustment unit is used to be electrically connected to the DC bus through the positive output capacitor.

3. The power supply control device according to claim 2, characterized in that, The negative electrode adjustment unit includes a negative electrode buck chopper topology subunit composed of a first energy storage inductor, a first power switch and a first freewheeling diode, and the positive electrode adjustment unit includes a positive electrode boost chopper topology subunit composed of a second energy storage inductor, a second power switch and a second freewheeling diode.

4. The power supply control device according to claim 3, characterized in that: The input terminal of the first power switch is electrically connected to the first terminal of the negative output capacitor and the input terminal of the second power switch, respectively, and is used to connect to the positive terminal of the DC power supply. The output terminal of the first power switch is electrically connected to the second terminal of the first energy storage inductor and the cathode of the first freewheeling diode, respectively. The first terminal of the first energy storage inductor is used to connect to the negative terminal of the DC power supply. The anode of the first freewheeling diode is electrically connected to the second terminal of the negative output capacitor, the anode of the second freewheeling diode, and the second terminal of the positive output capacitor, respectively, and is used to connect to the negative terminal of the DC bus. The output terminal of the second power switch is electrically connected to the first terminal of the second energy storage inductor and the cathode of the second freewheeling diode, respectively. The second terminal of the second energy storage inductor is electrically connected to the first terminal of the positive output capacitor and is used to connect to the positive terminal of the DC bus.

5. The power supply control device according to claim 2, characterized in that, The negative electrode adjustment unit includes a negative electrode boost chopper topology subunit composed of a third energy storage inductor, a third power switch, and a third freewheeling diode, and the positive electrode adjustment unit includes a positive electrode buck chopper topology subunit composed of a fourth energy storage inductor, a fourth power switch, and a fourth freewheeling diode.

6. The power supply control device according to claim 5, characterized in that: The cathode of the third freewheeling diode is electrically connected to the first terminal of the negative output capacitor and the first terminal of the fourth energy storage inductor, and is used to connect to the positive terminal of the DC power supply. The anode of the third freewheeling diode is electrically connected to the output terminal of the third power switch and the first terminal of the third energy storage inductor. The input terminal of the third power switch is used to connect to the negative terminal of the DC power supply. The second terminal of the third energy storage inductor is electrically connected to the second terminal of the negative output capacitor, the output terminal of the fourth power switch, and the second terminal of the positive output capacitor, and is used to connect to the negative terminal of the DC bus. The second terminal of the fourth energy storage inductor is electrically connected to the input terminal of the fourth power switch and the anode of the fourth freewheeling diode. The cathode of the fourth freewheeling diode is electrically connected to the first terminal of the positive output capacitor and is used to connect to the positive terminal of the DC bus.

7. The power supply control device according to any one of claims 2 to 6, characterized in that, The negative electrode adjustment module includes multiple negative electrode adjustment units connected in parallel, and / or the positive electrode adjustment module includes multiple positive electrode adjustment units connected in parallel.

8. A flow sharing control method, characterized in that, Applied to the power supply control device according to any one of claims 1 to 7; for each of the DC-DC converter circuits, the current sharing control method includes: Obtain the negative reference impedance, positive reference impedance, initial negative reference voltage, initial positive reference voltage, negative output current of the DC-DC converter circuit, and positive output current of the DC-DC converter circuit. Based on the positive reference impedance, the initial positive reference voltage, and the positive output current of the DC-DC converter circuit, the initial positive reference voltage is corrected to obtain the corrected positive reference voltage. Voltage loop control is then performed based on the corrected positive reference voltage to adjust the positive output current of the DC-DC converter circuit. Based on the negative reference impedance, the initial negative reference voltage, and the negative output current of the DC-DC converter circuit, the initial negative reference voltage is corrected to obtain a corrected negative reference voltage. Voltage loop control is then performed based on the corrected negative reference voltage to adjust the negative output current of the DC-DC converter circuit.

9. The flow sharing control method according to claim 8, characterized in that, The step of correcting the initial positive reference voltage based on the positive reference impedance, the initial positive reference voltage, and the positive output current of the DC-DC converter circuit to obtain the corrected positive reference voltage includes: Determine the first product of the positive output current of the DC-DC converter circuit and the positive reference impedance; Determine the first difference between the initial positive reference voltage and the first product value; The first difference is used as the corrected positive reference voltage.

10. The flow sharing control method according to claim 8, characterized in that, The step of correcting the initial negative reference voltage based on the negative reference impedance, the initial negative reference voltage, and the negative output current of the DC-DC converter circuit to obtain the corrected negative reference voltage includes: Determine the second product value of the negative output current of the DC-DC converter circuit and the negative reference impedance; Determine the second difference between the initial negative reference voltage and the second product value; The second difference is used as the corrected negative reference voltage.

11. A flow sharing control method, characterized in that, Applied to the power supply control device according to any one of claims 1 to 7; for each of the DC-DC converter circuits, the current sharing control method includes: Obtain the negative output current of the DC-DC converter circuit, the positive output current of the DC-DC converter circuit, the negative output current of other DC-DC converter circuits, and the positive output current of other DC-DC converter circuits. Determine the negative output current of the DC-DC converter circuit and the average negative current of the negative output current of other DC-DC converter circuits, and adjust the negative output current of the DC-DC converter circuit according to the average negative current. Determine the positive output current of the DC-DC converter circuit and the average positive current of the positive output current of other DC-DC converter circuits, and adjust the positive output current of the DC-DC converter circuit according to the average positive current.

12. An electrical system, characterized in that, The electrical system includes a DC power supply, a DC bus, a DC load, and a power supply control device as described in any one of claims 1 to 7; The DC load is electrically connected to the DC bus.

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