Independent control method and related device of DC power supply

Abstract

The present invention provides an independent control method for a DC power supply and a related device, the method comprising: obtaining the actual battery current of the battery module corresponding to the current power supply device in the current cycle; calculating the difference between the actual battery current and the equalization current set value to obtain the battery current difference; obtaining the actual bus current value of the bus-coupled section between at least two rectifier cabinets in the current cycle, and judging whether the actual bus current value meets the preset conditions; if the actual bus current value meets the preset conditions, calculating the bus reference value of the current cycle based on the actual bus current value; calculating the preset voltage value of the current cycle based on the battery current difference and the bus reference value of the current cycle, and controlling the output voltage of the rectifier cabinet corresponding to the current power supply device based on the preset voltage value of the current cycle. The present application can, when the bus-coupled section current does not meet the preset conditions, supplement the bus current control on the basis of the equalization logic, thereby avoiding the problem of battery current overcurrent.

Description

Technical Field

[0001] The present invention relates to the technical field of power supplies, and in particular to an independent control method for a direct current power supply and related devices. Background Art

[0002] The core of a data center's power supply architecture is the uninterruptible power system (UPS), comprised primarily of AC UPS (uninterruptible power system) and DC HVDC (high voltage direct current) power transmission. To meet the power supply requirements of data centers at varying reliability levels, the industry currently employs various UPS architecture solutions.

[0003] To ensure the reliability of medium-voltage direct power supply, current consideration is to add a bus tie device on the low-voltage side of at least two rectifier cabinets to improve equipment reliability. Low-voltage bus ties are divided into AC bus tie devices and DC bus tie devices. For DC bus tie devices, existing control methods often cause overcurrent problems in one battery module group when the battery capacities of the two rectifier cabinets are inconsistent. Summary of the Invention

[0004] In view of this, the present invention provides an independent control method and related device for a DC power supply, which can solve the battery overcurrent problem caused by inconsistent battery capacity of two rectifier cabinets in a medium-voltage direct power supply with a busbar device set on the low-voltage side.

[0005] In a first aspect, an embodiment of the present invention provides an independent control method for a DC power supply, wherein the DC power supply includes a DC bus coupling device and at least two power supply devices, wherein the power supply devices include a rectifier cabinet, a battery module, and a monitoring unit;

[0006] The DC output terminal of each rectifier cabinet is connected to the corresponding battery module, and the DC bus coupling device is connected between the DC output terminals of at least two rectifier cabinets;

[0007] The method is applied to a monitoring unit corresponding to any power supply device, and includes:

[0008] Obtain the actual battery current of the battery module corresponding to the current power supply device in the current cycle;

[0009] Calculating the difference between the actual battery current and the equalization current setting value to obtain a battery current difference;

[0010] Obtaining an actual bus-coupling current value of a bus-coupling section between at least two rectifier cabinets in a current cycle, and determining whether the actual bus-coupling current value meets a preset condition;

[0011] If the actual value of the bus coupling current meets the preset condition, calculating the bus coupling reference value of the current cycle based on the actual value of the bus coupling current;

[0012] Based on the battery current difference and the bus reference value of the current cycle, the preset voltage value of the current cycle is calculated, and based on the preset voltage value of the current cycle, the output voltage of the rectifier cabinet corresponding to the current power supply device is controlled.

[0013] In a second aspect, an embodiment of the present invention provides an independent control device for a DC power supply, wherein the DC power supply includes a DC bus coupling device and at least two power supply devices, wherein the power supply devices include a rectifier cabinet, a battery module, and a monitoring unit;

[0014] The DC output terminal of each rectifier cabinet is connected to the corresponding battery module, and the DC bus coupling device is connected between the DC output terminals of at least two rectifier cabinets;

[0015] The independent control device of the DC power supply is applied to the monitoring unit corresponding to any power supply device, including:

[0016] An actual battery current acquisition module is used to obtain the actual battery current of the battery module corresponding to the current power supply device in the current cycle;

[0017] a battery current difference calculation module, configured to calculate the difference between the actual battery current and the equalization current set value to obtain the battery current difference;

[0018] A busbar current judgment module is used to obtain the actual busbar current value of the busbar section between at least two rectifier cabinets in the current cycle, and judge whether the actual busbar current value meets the preset conditions;

[0019] a bus coupling reference value calculation module, configured to calculate a bus coupling reference value for a current cycle based on the actual bus coupling current value if the actual bus coupling current value satisfies a preset condition;

[0020] The voltage control module is used to calculate the preset voltage value of the current cycle based on the battery current difference and the bus reference value of the current cycle, and control the output voltage of the rectifier cabinet corresponding to the current power supply device based on the preset voltage value of the current cycle.

[0021] In a third aspect, an embodiment of the present invention provides a monitoring unit comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method described in any possible implementation of the first aspect above are implemented.

[0022] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in any possible implementation of the first aspect above are implemented.

[0023] In a fifth aspect, an embodiment of the present invention provides a DC power supply comprising: a DC bus coupling device and at least two power supply devices, wherein the power supply devices include a rectifier cabinet, a battery module, and the monitoring unit described in the third aspect above;

[0024] The DC output end of each rectifier cabinet is connected to the corresponding battery module, and the DC bus coupling device is connected between the DC output ends of at least two rectifier cabinets.

[0025] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0026] The embodiment of the present invention obtains the actual battery current of the battery module corresponding to the current power supply device in the current cycle; calculates the difference between the actual battery current and the equalization current setting value to obtain the battery current difference; obtains the actual value of the bus current of the bus section between at least two rectifier cabinets in the current cycle, and determines whether the actual value of the bus current meets the preset conditions; if the actual value of the bus current meets the preset conditions, the bus reference value of the current cycle is calculated based on the actual value of the bus current; based on the battery current difference and the bus reference value of the current cycle, the preset voltage value of the current cycle is calculated, and the output voltage of the rectifier cabinet corresponding to the current power supply device is controlled based on the preset voltage value of the current cycle. The present application can, when the bus section current does not meet the preset conditions, supplement the bus current control on the basis of the equalization logic, thereby avoiding the problem of battery current overcurrent. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 This is a schematic structural diagram of a DC power supply provided by an embodiment of the present invention;

[0029] Figure 2 is another structural schematic diagram of a DC power supply provided by an embodiment of the present invention;

[0030] Figure 3 This is a flow chart of an implementation method of an independent control method of a DC power supply provided by an embodiment of the present invention;

[0031] Figure 4This is a control block diagram of an independent control method for a DC power supply provided by an embodiment of the present invention;

[0032] Figure 5 : is a schematic diagram of simulation data provided by an embodiment of the present application, wherein: Figure 5 a shows a schematic diagram of a simulation curve of the sum of the actual battery currents of the battery modules of the two cabinets; Figure 5 b shows a schematic diagram of a simulation curve of the actual value of the busbar current; Figure 5 c shows the actual battery current diagram of a battery module with low battery capacity. Figure 5 d shows the actual battery current diagram of a battery module with high battery capacity;

[0033] Figure 6 1 is a schematic structural diagram of an independent control device for a DC power supply provided by an embodiment of the present invention;

[0034] Figure 7 is a schematic diagram of a monitoring unit provided in an embodiment of the present invention;

[0035] Figure 8 1 is a schematic structural diagram of a DC power supply including multiple monitoring devices provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0036] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0037] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below with reference to the accompanying drawings.

[0038] Figure 1 and Figure 2 The schematic diagrams of the structure of the DC power supply provided by the embodiment of the present invention respectively show two power supply devices. Figure 8 The structure diagram of a DC power supply provided by an embodiment of the present invention is shown, in which multiple power supply devices are connected via a DC bus coupling device. Figure 1 、 Figure 2 and Figure 8 , the DC power supply includes: a DC busbar device and at least two power supply devices, the power supply device includes a rectifier cabinet, a battery module and a monitoring unit;

[0039] The DC output end of each rectifier cabinet is connected to the corresponding battery module, and the DC bus coupling device is connected between the DC output ends of at least two rectifier cabinets.

[0040] like Figure 1 or Figure 2 As shown, the power supply device also includes a phase-shifting transformer and a power distribution unit. Specifically, the mains power is connected to the high-voltage side of the phase-shifting transformer, the low-voltage side of the phase-shifting transformer is connected to the AC side of the rectifier cabinet, and the DC output of the rectifier cabinet is connected to the battery module and the power distribution unit respectively. At least two rectifier cabinets are connected via a DC busbar.

[0041] Among them, the DC bus coupling device includes a DC bus coupling device of the circuit breaker normally closed type and a DC bus coupling device of the fuse normally closed type. Figure 1 As shown, the DC bus coupling device of the circuit breaker normally closed type includes a circuit breaker switch K1, which is in a normally closed state. Figure 2 As shown, the DC bus coupling device in the normally closed fuse form is the fuse PUSE.

[0042] When the above-mentioned DC bus coupling device is operating normally, at least two power supply devices are output-coupled, and at least two power supply devices can exchange information during operation. When any one of the mains power lines is abnormally cut off, the other line can directly achieve power supply continuity for the load through the bus coupling section.

[0043] Specifically, the winding angles of the phase-shifting transformers of the at least two power supply units interconnected can be aligned, or they can be staggered in parallel to form 72 pulses. From a practical perspective, the 72-pulse staggered parallel connection produces less output ripple than the 36-pulse connection with the same angle. To ensure structural consistency, at least two rectifier cabinets are equipped with fuses PUSE and current Hall effect sensors HL in the bus-coupler section. The current Hall effect sensors are used to collect the actual bus-coupler current value in the bus-coupler section and transmit it to the monitoring unit within the cabinet.

[0044] Specifically, each rectifier cabinet includes multiple rectifier modules, and the multiple rectifier modules are connected in parallel for output.

[0045] In this embodiment, a DC bus coupler device with a larger line resistance can be selected. The larger the line resistance, the smaller the current of the DC bus coupler section, and the smaller the mutual influence between the cabinets.

[0046] See also Figure 3 , which shows a flowchart of an independent control method for a DC power supply provided by an embodiment of the present invention. The control method is applied to the monitoring unit in the above-mentioned DC power supply, and is described in detail as follows:

[0047] S101: Acquire the actual battery current of the battery module corresponding to the current power supply device in the current cycle.

[0048] In this embodiment, each monitoring unit is used to independently control its corresponding power supply device.

[0049] First, for each monitoring unit, the monitoring unit collects the actual battery current in the power supply device through a Hall current sensor.

[0050] S102: Calculate the difference between the actual battery current and the equalization current setting value to obtain a battery current difference.

[0051] In this embodiment, each monitoring device is preset with a setting value of the equalization charging current of the power supply device, which is used to control the battery modules in the power supply device using equalization charging logic.

[0052] Specifically, such as Figure 4 As shown, Figure 4 The independent control block diagram of the DC power supply provided in this embodiment is shown. bat_ret Subtract the actual battery current I bat_fb , get the battery current difference of the current cycle.

[0053] S103: Obtain an actual value of a bus-coupling current of a bus-coupling section between at least two rectifier cabinets in a current cycle, and determine whether the actual value of the bus-coupling current meets a preset condition.

[0054] In this embodiment, when each power supply device is independently controlled using the equalization logic, if the battery capacity corresponding to each power supply device is consistent, the battery module can still correctly execute the equalization logic even if the load amount is inconsistent. However, when the battery capacity is inconsistent, a capacity difference of 2% will cause the rectifier cabinet with a lower capacity to not output. The reason is that its charging current is provided by the rectifier cabinet of another power supply device, and the charging current exceeds the equalization current, resulting in the voltage of this power supply device being reduced when controlled according to the equalization logic, and eventually reduced to the lowest point of the set voltage of 220V.

[0055] When the actual system is running, there must be a gap in the battery capacity of the two power supply devices, so it is not feasible to use the logic of independent equalization control of the two power supply devices. This embodiment takes into account the reason why the above control does not work is that the two power supply devices each have only one equalization current setting value as the control target, and this control target will affect the control of the other power supply device. On this basis, because there is a DC interaction of the bus section between the two cabinets, this embodiment can add the current of the bus section to the control loop, correct the loop, increase the control of the bus current, ensure that the bus current does not exceed the limit, and the bus section voltage approaches zero.

[0056] In one possible embodiment, Figure 4 As shown, the preset condition is the actual value of the busbar current I bus_fb The absolute value is greater than the preset current value I bus_H .

[0057] Specifically, if the actual value of the busbar current I bus_fb The absolute value is greater than the preset current value I bus_H , indicating that the busbar current exceeds the limit, so it is necessary to add the busbar current control to the equalizing charge control logic.

[0058] S104: If the actual value of the bus coupling current meets a preset condition, a bus coupling reference value of the current cycle is calculated based on the actual value of the bus coupling current.

[0059] S105: Calculate a preset voltage value for the current cycle based on the battery current difference and the bus tie reference value for the current cycle, and control the output voltage of the rectifier cabinet corresponding to the current power supply device based on the preset voltage value for the current cycle.

[0060] In this embodiment, after the preset voltage value of the current cycle is calculated, the preset voltage value is sent to the rectifier module corresponding to the power supply device, so that the rectifier module controls its output voltage based on the preset voltage value.

[0061] It can be seen from the above embodiments that when the busbar current does not meet the preset conditions, this embodiment can supplement the busbar current control based on the equalization logic, thereby ensuring that the busbar current is zero and avoiding the battery current overcurrent problem.

[0062] In one possible embodiment, Figure 4 As shown, the specific implementation process of S104 includes:

[0063] Set the busbar current to I bus_ret Subtract the actual value of the busbar current I bus_fb , get the busbar current difference of the current cycle;

[0064] The bus coupling current difference is input into a first PI controller to obtain a bus coupling reference value of the current cycle.

[0065] Specifically, in this step, since the current flow direction of the bus-link section is different under different circumstances, this embodiment can only pre-store the numerical value of the bus-link current setting value in the monitoring unit. When it is determined that the actual value of the bus-link current meets the preset conditions, the current sign of the actual value of the bus-link current is obtained, and the current sign of the actual value of the bus-link current is used as the sign of the bus-link current setting value, that is, the numerical value of the bus-link current setting value is multiplied by the current sign of the actual value of the bus-link current to obtain the bus-link current setting value, and then the actual value of the bus-link current is subtracted from the bus-link current setting value to obtain the bus-link current difference, and the bus-link current difference is input into the first PI controller to obtain the bus-link reference value.

[0066] In one possible embodiment, Figure 4 As shown, after S103, the method provided in this embodiment further includes:

[0067] If the actual value of the busbar current I bus_fb If the preset condition is not met, the bus tie reference value is set to zero.

[0068] In this embodiment, if the actual value of the busbar current I bus_fb The absolute value is not greater than the preset current value I bus_H , indicating that the difference in battery capacity between the two power supply devices is not large, so there is no need to consider the bus tie current and the bus tie reference value is set to zero.

[0069] In one possible embodiment, Figure 4 As shown, the specific implementation process of S105 includes:

[0070] Inputting the battery current difference of the current cycle into a second PI controller to obtain a first voltage value of the current cycle;

[0071] Subtracting the first voltage value of the current cycle from the preset voltage value of the previous cycle to obtain a preset voltage difference;

[0072] Add the preset voltage difference to the bus reference value to obtain the preset voltage value U of the current cycle. ret .

[0073] In a possible embodiment, after obtaining the preset voltage value of the current cycle, the method provided by this embodiment further includes:

[0074] Limit the preset voltage value of the current cycle.

[0075] In a possible embodiment, the independent control method of the DC power supply provided in this embodiment further includes:

[0076] If a power-off signal of another power supply device is detected, it is determined whether the actual battery current of the current cycle is greater than the lower limit of the equalization current. If the actual battery current of the current cycle is greater than the lower limit of the equalization current, the set value of the equalization current is maintained unchanged;

[0077] If the actual battery current of the current cycle is less than or equal to the equalization current lower limit, the actual battery current of the current cycle is used as the equalization current setting value;

[0078] Calculate the difference between the actual battery current and the equalization current setting value to obtain the battery current difference, calculate the preset voltage value of the current cycle based on the battery current difference of the current cycle, and control the output voltage of the rectifier cabinet corresponding to the current power supply device based on the preset voltage value of the current cycle.

[0079] In this embodiment, the present application can add a dry contact for mains power failure to each power supply device. The monitoring unit of one power supply device collects the dry contact signal of the mains power failure of another power supply device. If the power supply device detects the mains power failure signal of the other power supply device, it will no longer execute the independent control logic of S101 to S105, but will switch to the equalization control logic of a single power supply device. In addition, in the process of executing the equalization control logic of a single power supply device, if the actual battery current of the current cycle is greater than the lower limit of the equalization current, the current equalization current setting value is maintained unchanged; if the actual battery current of the current cycle is less than or equal to the lower limit of the equalization current, the actual battery current of the current cycle is used as the equalization current setting value, and the equalization current setting value is maintained unchanged, and the preset voltage value of the subsequent cycle is calculated until the actual battery current is greater than the lower limit of the equalization current.

[0080] After determining the equalization current setting value of the current cycle, the equalization current setting value is subtracted from the actual battery current to obtain the battery current difference of the current cycle, and then the battery current difference is input into the second PI controller to obtain the first voltage value of the current cycle; the preset voltage value of the previous cycle is subtracted from the first voltage value of the current cycle to obtain the preset voltage value U ret .

[0081] Specifically, the lower limit value of the equalization current can be obtained by subtracting the unit preset current value from the initial equalization current setting value. For example, the unit preset current value can be 3A.

[0082] The above method can ensure the normal operation of the DC power supply and avoid the situation where the mains power failure of one power supply device causes the battery discharge of another normal power supply device.

[0083] In one embodiment of the present application, the battery capacities of the battery modules of the power supply devices are inconsistent, and the above method is used for simulation, as shown in the simulation diagram. Figure 5 a to Figure 5 As shown in Figure d, it can be seen from the simulation diagram that: after the busbar current is controlled, the charging current of the rectifier cabinet with smaller battery capacity can be controlled within the equalization current setting value, while the charging current of the rectifier cabinet with higher battery capacity can be controlled below the equalization current setting value. The system can also achieve control to ensure that the current charging of the two cabinets will not cause overcurrent.

[0084] In one embodiment of the present invention, when performing a battery discharge test and an insulation test on a DC power supply, each power supply device needs to establish a communication connection to implement time-sharing execution of the above two tests.

[0085] In one embodiment of the present invention, after S102, the method further includes:

[0086] Determine whether the fuse between the two rectifier cabinets is disconnected. If not, proceed to step S103.

[0087] If the fuse between the two rectifier cabinets is broken, remove the busbar current control loop and directly perform the following steps:

[0088] Based on the battery current difference in the current cycle, a preset voltage value in the current cycle is calculated, and based on the preset voltage value in the current cycle, the output voltage of the rectifier cabinet corresponding to the current power supply device is controlled.

[0089] Specifically, the above steps are as follows:

[0090] Inputting the battery current difference of the current cycle into a second PI controller to obtain a first voltage value of the current cycle;

[0091] The first voltage value of the current cycle and the preset voltage value of the previous cycle are summed to obtain the preset voltage value of the current cycle.

[0092] As can be seen from the above embodiment, this embodiment provides independent voltage control between power supply devices, a fast control cycle, and guaranteed correct control even in the event of a communication failure. Furthermore, the method provided by this embodiment optimally ensures zero current in the busbar segment, clamping the voltage to ensure that the battery module with the lower capacity achieves the equalized charging current while preventing current from flowing through the other battery module.

[0093] It should be understood that the order of execution of the steps in the above embodiments does not necessarily mean the order of execution. The order of execution of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0094] The following are device embodiments of the present invention. For details not fully described therein, reference may be made to the corresponding method embodiments described above.

[0095] Figure 6 A schematic diagram of the structure of an independent control device for a DC power supply provided in an embodiment of the present invention is shown. The independent control device for a DC power supply is applied to a monitoring unit corresponding to any power supply device. For ease of illustration, only the parts related to the embodiment of the present invention are shown, which are described in detail as follows:

[0096] like Figure 6 As shown, the independent control device 100 of the DC power supply includes:

[0097] The actual battery current acquisition module 110 is used to obtain the actual battery current of the battery module corresponding to the current power supply device in the current cycle;

[0098] a battery current difference calculation module 120, configured to calculate the difference between the actual battery current and the equalization current setting value to obtain the battery current difference;

[0099] The busbar current determination module 130 is configured to obtain an actual busbar current value of a busbar section between at least two rectifier cabinets in a current cycle and determine whether the actual busbar current value meets a preset condition;

[0100] a bus coupling reference value calculation module 140, configured to calculate a bus coupling reference value for a current cycle based on the actual bus coupling current value if the actual bus coupling current value satisfies a preset condition;

[0101] The voltage control module 150 is used to calculate the preset voltage value of the current cycle based on the battery current difference and the bus reference value of the current cycle, and control the output voltage of the rectifier cabinet corresponding to the current power supply device based on the preset voltage value of the current cycle.

[0102] In a possible embodiment, the bus coupling reference value calculation module 140 includes:

[0103] Subtract the actual bus-coupling current value from the bus-coupling current set value to obtain the bus-coupling current difference value of the current cycle;

[0104] The bus coupling current difference is input into a first PI controller to obtain a bus coupling reference value of the current cycle.

[0105] In a possible embodiment, the independent control device 100 of the DC power supply further includes a bus-coupler reference value zeroing module for:

[0106] If the actual value of the bus coupling current does not meet the preset condition, the bus coupling reference value is set to zero.

[0107] In a possible embodiment, the preset condition is that the absolute value of the actual value of the bus-connection current is greater than a preset current value.

[0108] In one possible embodiment, the voltage control module 150 includes:

[0109] Inputting the battery current difference of the current cycle into a second PI controller to obtain a first voltage value of the current cycle;

[0110] Subtracting the first voltage value of the current cycle from the preset voltage value of the previous cycle to obtain a preset voltage difference;

[0111] The preset voltage difference is added to the bus tie reference value to obtain a preset voltage value for the current cycle.

[0112] In a possible embodiment, the independent control device 100 for a DC power supply further includes:

[0113] The limiting module is used to limit the preset voltage value of the current cycle.

[0114] The independent control device of the DC power supply provided by the embodiment of the present invention first obtains the actual battery current of the battery module corresponding to the current power supply device in the current cycle; calculates the difference between the actual battery current and the equalization current setting value to obtain the battery current difference; and obtains the actual value of the bus current of the bus section between at least two rectifier cabinets in the current cycle, and determines whether the actual value of the bus current meets the preset conditions; if the actual value of the bus current meets the preset conditions, the bus reference value of the current cycle is calculated based on the actual value of the bus current; finally, based on the battery current difference and the bus reference value of the current cycle, the preset voltage value of the current cycle is calculated, and the output voltage of the rectifier cabinet corresponding to the current power supply device is controlled based on the preset voltage value of the current cycle. This embodiment can, when the bus current of the bus section does not meet the preset conditions, supplement the bus current control on the basis of the equalization logic, thereby ensuring that the bus current of the bus section is zero and avoiding the problem of battery current overcurrent.

[0115] The independent control device of the DC power supply provided in this embodiment can be used to execute the above-mentioned independent control method embodiment of the DC power supply. Its implementation principle and technical effects are similar and will not be described in detail in this embodiment.

[0116] Figure 7 FIG is a schematic diagram of a monitoring unit provided by an embodiment of the present invention. Figure 7 As shown, the monitoring unit 7 of this embodiment includes: a processor 70, a memory 71, and a computer program 72 stored in the memory 71 and executable on the processor 70. When the processor 70 executes the computer program 72, the steps of the above-mentioned independent control method of each DC power supply are implemented, for example Figure 3 Alternatively, when the processor 70 executes the computer program 72, the functions of the modules / units in the above-mentioned device embodiments are realized, for example, Figure 6 The functions of the modules 110 to 150 are shown.

[0117] Exemplarily, the computer program 72 may be divided into one or more modules / units, which are stored in the memory 71 and executed by the processor 70 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, and the instruction segments are used to describe the execution process of the computer program 72 in the monitoring unit 7.

[0118] The monitoring unit 7 can be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The monitoring unit 7 can include, but is not limited to, a processor 70 and a memory 71. Those skilled in the art will understand that Figure 7 It is only an example of the monitoring unit 7 and does not constitute a limitation of the monitoring unit 7. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the monitoring unit may also include input and output devices, network access devices, buses, etc.

[0119] The processor 70 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0120] The memory 71 can be an internal storage unit of the monitoring unit 7, such as a hard drive or memory of the monitoring unit 7. The memory 71 can also be an external storage device of the monitoring unit 7, such as a plug-in hard drive, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc. equipped on the monitoring unit 7. Furthermore, the memory 71 can include both the internal storage unit of the monitoring unit 7 and an external storage device. The memory 71 is used to store the computer program and other programs and data required by the monitoring unit. The memory 71 can also be used to temporarily store data that has been output or is about to be output.

[0121] Those skilled in the art can clearly understand that, for the convenience and brevity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0122] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant description of other embodiments.

[0123] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present invention.

[0124] In the embodiments provided by the present invention, it should be understood that the disclosed devices / monitoring units and methods can be implemented in other ways. For example, the device / monitoring unit embodiments described above are merely illustrative. For example, the division of the modules or units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, and can be electrical, mechanical or other forms.

[0125] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0126] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0127] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, it can implement the steps of the above-mentioned independent control method embodiments of each DC power supply. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium can include: any entity or device that can carry the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practices in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practices, computer-readable media does not include electrical carrier signals and telecommunication signals.

[0128] The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A method for independent control of a DC power supply, characterized in that: The DC power supply includes a DC busbar device and at least two power supply devices, and the power supply device includes a rectifier cabinet, a battery module and a monitoring unit; The DC output terminal of each rectifier cabinet is connected to the corresponding battery module, and the DC bus coupling device is connected between the DC output terminals of at least two rectifier cabinets; The method is applied to a monitoring unit corresponding to any power supply device, and includes: Obtain the actual battery current of the battery module corresponding to the current power supply device in the current cycle; Calculating the difference between the actual battery current and the equalization current setting value to obtain a battery current difference; Obtaining an actual bus-coupling current value of a bus-coupling section between at least two rectifier cabinets in a current cycle, and determining whether the actual bus-coupling current value meets a preset condition; If the actual bus-coupling current value satisfies a preset condition, the actual bus-coupling current value is subtracted from the bus-coupling current set value to obtain a bus-coupling current difference value for the current cycle; the bus-coupling current difference value is input into a first PI controller to obtain a bus-coupling reference value for the current cycle; The battery current difference of the current cycle is input into the second PI controller to obtain the first voltage value of the current cycle; the preset voltage value of the previous cycle is subtracted from the first voltage value of the current cycle to obtain the preset voltage difference; the preset voltage difference is added to the bus reference value to obtain the preset voltage value of the current cycle, and the output voltage of the rectifier cabinet corresponding to the current power supply device is controlled based on the preset voltage value of the current cycle.

2. The independent control method of a DC power supply according to claim 1, characterized in that: After determining whether the actual value of the bus-coupler current meets a preset condition, the method further includes: If the actual value of the bus coupling current does not meet the preset condition, the bus coupling reference value is set to zero.

3. The independent control method of a DC power supply according to claim 1, characterized in that: The preset condition is that the absolute value of the actual value of the bus-connection current is greater than the preset current value.

4. The independent control method of a DC power supply according to claim 1, characterized in that: The method further comprises: If a power-off signal of another power supply device is detected, it is determined whether the actual battery current of the current cycle is greater than the lower limit of the equalization current. If the actual battery current of the current cycle is greater than the lower limit of the equalization current, the set value of the equalization current is maintained unchanged; If the actual battery current of the current cycle is less than or equal to the equalization current lower limit, the actual battery current of the current cycle is used as the equalization current setting value; Calculate the difference between the actual battery current and the equalization current setting value to obtain the battery current difference, calculate the preset voltage value of the current cycle based on the battery current difference of the current cycle, and control the output voltage of the rectifier cabinet corresponding to the current power supply device based on the preset voltage value of the current cycle.

5. An independent control device for a DC power supply, characterized in that: The DC power supply includes a DC busbar device and at least two power supply devices, and the power supply device includes a rectifier cabinet, a battery module and a monitoring unit; The DC output terminal of each rectifier cabinet is connected to the corresponding battery module, and the DC bus coupling device is connected between the DC output terminals of at least two rectifier cabinets; The independent control device of the DC power supply is applied to the monitoring unit corresponding to any power supply device, including: An actual battery current acquisition module is used to obtain the actual battery current of the battery module corresponding to the current power supply device in the current cycle; a battery current difference calculation module, configured to calculate the difference between the actual battery current and the equalization current set value to obtain the battery current difference; A busbar current judgment module is used to obtain the actual busbar current value of the busbar section between at least two rectifier cabinets in the current cycle, and judge whether the actual busbar current value meets the preset conditions; a bus coupling reference value calculation module, configured to calculate a bus coupling reference value for a current cycle based on the actual bus coupling current value if the actual bus coupling current value satisfies a preset condition; a voltage control module, configured to calculate a preset voltage value for the current cycle based on the battery current difference and the bus-coupler reference value of the current cycle, and control the output voltage of the rectifier cabinet corresponding to the current power supply device based on the preset voltage value of the current cycle; The bus coupling reference value calculation module includes: Subtract the actual bus-coupling current value from the bus-coupling current set value to obtain the bus-coupling current difference value of the current cycle; Inputting the bus coupling current difference into a first PI controller to obtain a bus coupling reference value of the current cycle; The voltage control module includes: Inputting the battery current difference of the current cycle into a second PI controller to obtain a first voltage value of the current cycle; Subtracting the first voltage value of the current cycle from the preset voltage value of the previous cycle to obtain a preset voltage difference; The preset voltage difference is added to the bus tie reference value to obtain a preset voltage value for the current cycle.

6. A monitoring unit comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: The memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to perform the method according to any one of claims 1 to 4.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

8. A DC power supply, characterized in that: include: A DC bus coupling device and at least two power supply devices, wherein the power supply device includes a rectifier cabinet, a battery module and the monitoring unit according to claim 6; The DC output end of each rectifier cabinet is connected to the corresponding battery module, and the DC bus coupling device is connected between the DC output ends of at least two rectifier cabinets.

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