Master-slave control method and related device for DC power supply

Abstract

The present invention provides a master-slave control method and related devices for a DC power supply, the method comprising: adding the actual battery currents corresponding to the master power supply device and the slave power supply device of the current cycle to obtain the sum of the actual battery currents; calculating the preset voltage value of the current cycle based on the difference between the sum of the actual battery currents of the current cycle and the sum of the preset equalization currents; and controlling the output voltage of the master rectifier cabinet based on the preset voltage value; sending the preset voltage value to the slave monitoring unit so that the slave monitoring unit controls the output voltage of the slave rectifier cabinet based on the preset voltage value. Through the above method, when facing a power outage of the mains power of one power supply device, the present application can still obtain the battery current of the power supply device through the master monitoring unit to achieve control of the total battery current of the power supply devices of the two cabinets, thereby avoiding the problem of the system losing control due to the power outage of one mains power.

Description

Technical Field

[0001] The present invention relates to the technical field of power supplies, and in particular to a master-slave 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, the current approach is to add a busbar coupling device to the low-voltage side of the two rectifier cabinets to improve equipment reliability. The busbar coupling on the low-voltage side is divided into AC busbar coupling and DC busbar coupling. For DC busbar coupling structures, the current common control method is to independently control the current sharing of each rectifier cabinet. However, when the mains power is normal, the current in the busbar section is low. If the loop design is reasonable, the current in the busbar section can be guaranteed to be zero, and the voltage is then clamped, ensuring reliable power supply to each rectifier cabinet. However, if one mains power line fails, the current from the other lines will be fed to the low-voltage side of the rectifier cabinet that lost power through the busbar coupling device. At this time, if each rectifier cabinet still controls its own output voltage according to the independent current sharing control logic, the system will be at risk of loss of control. Summary of the Invention

[0004] In view of this, the present invention provides a master-slave control method and related device for a DC power supply, which can solve the problem of control failure of a DC power supply with a DC bus-coupled structure using an existing control method when the mains power is lost.

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

[0006] The DC output end of the master rectifier cabinet is connected to the master battery module; the DC output end of the slave rectifier cabinet is connected to the slave battery module, and the DC bus coupling device is connected between the DC output end of the master rectifier cabinet and the DC output end of the slave rectifier cabinet;

[0007] The method is applied to the main monitoring unit and includes:

[0008] Obtaining the actual battery current of the main battery module in the current cycle;

[0009] Acquiring an actual battery current of the slave battery module in a current cycle collected by the slave monitoring unit;

[0010] Adding the actual battery current of the master battery module and the actual battery current of the slave battery module in the current cycle to obtain a sum of the actual battery currents;

[0011] Calculating a preset voltage value for the current cycle based on the difference between the sum of the actual battery currents in the current cycle and the sum of the preset equalization currents; and controlling the output voltage of the main rectifier cabinet based on the preset voltage value for the current cycle;

[0012] The preset voltage value of the current cycle is sent to the slave monitoring unit, so that the slave monitoring unit controls the output voltage of the slave rectifier cabinet based on the preset voltage value.

[0013] In a second aspect, an embodiment of the present invention provides a master-slave control device for a DC power supply, wherein the DC power supply includes a DC bus coupling device, a master power supply device, and at least one slave power supply device, wherein the master power supply device includes a master rectifier cabinet, a master battery module, and a master monitoring unit; and the slave power supply device includes a slave rectifier cabinet, a slave battery module, and a slave monitoring unit.

[0014] The DC output end of the master rectifier cabinet is connected to the master battery module; the DC output end of the slave rectifier cabinet is connected to the slave battery module, and the DC bus coupling device is connected between the DC output end of the master rectifier cabinet and the DC output end of the slave rectifier cabinet;

[0015] The master-slave control device of the DC power supply is applied to the master monitoring unit and includes:

[0016] A main battery current acquisition module, used to obtain the actual battery current of the main battery module in the current cycle;

[0017] A slave battery current acquisition module, configured to acquire the actual battery current of the slave battery module in the current cycle collected by the slave monitoring unit;

[0018] a battery current summing module, configured to add the actual battery current of the master battery module and the actual battery current of the slave battery module in a current cycle to obtain a sum of the actual battery currents;

[0019] A main voltage control module, configured to calculate a preset voltage value for the current cycle based on the difference between the sum of the actual battery currents in the current cycle and the sum of the preset equalization currents; and to control the output voltage of the main rectifier cabinet based on the preset voltage value for the current cycle;

[0020] The slave voltage control module is configured to send the preset voltage value of the current cycle to the slave monitoring unit, so that the slave monitoring unit controls the output voltage of the slave rectifier cabinet based on the preset voltage value.

[0021] In a third aspect, an embodiment of the present invention provides a main 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, a master power supply device, and at least one slave power supply device, wherein the master power supply device comprises a master rectifier cabinet, a master battery module, and the master monitoring unit described in the third aspect above; and the slave power supply device comprises a slave rectifier cabinet, a slave battery module, and a slave monitoring unit.

[0024] The DC output end of the main rectifier cabinet is connected to the main battery module; the DC output end of the slave rectifier cabinet is connected to the slave battery module, and the DC bus coupling device is connected between the DC output end of the main rectifier cabinet and the DC output end of the slave rectifier cabinet.

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

[0026] The embodiment of the present invention first obtains the actual battery current of the master battery module in the current cycle and the actual battery current of the slave battery module in the current cycle; then adds the actual battery current of the master battery module in the current cycle to the actual battery current of the slave battery module to obtain the sum of the actual battery currents; finally, based on the difference between the sum of the actual battery currents in the current cycle and the sum of the preset equalization currents, calculates the preset voltage value of the current cycle; and controls the output voltage of the master rectifier cabinet based on the preset voltage value of the current cycle; and sends the preset voltage value of the current cycle to the slave monitoring unit so that the slave monitoring unit controls the output voltage of the slave rectifier cabinet based on the preset voltage value. Through the above method, the embodiment of the present application can control the master and slave power supply devices through the master monitoring unit. Even if the mains power of one power supply device is cut off, the current of the other power supply devices can still flow to the output end of the power supply device that has been cut off through the DC bus device, thereby ensuring the power supply continuity of all power supply devices. At the same time, the master monitoring unit can timely adjust the output voltage of several other power supply devices with normal mains power according to the sum of the battery currents of each power supply device, thereby further ensuring the power supply reliability on the basis of ensuring the power supply continuity of all power supply devices, and avoiding the problem of system out of control due to mains power failure. 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 flowchart of the master-slave control method for a DC power supply provided by an embodiment of the present invention;

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

[0032] Figure 5 This is a communication connection diagram of a DC power supply provided in an embodiment of the present application;

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

[0034] Figure 7is a schematic diagram of a main monitoring unit provided by 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 respectively show the structures of a DC power supply including two power supply devices provided in an embodiment of the present invention. 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 or Figure 2 The DC power supply includes a DC bus coupling device, a main power supply device and at least one slave power supply device, the main power supply device includes a main rectifier cabinet, a main battery module and a main monitoring unit; the slave power supply device includes a slave rectifier cabinet, a slave battery module and a slave monitoring unit;

[0039] The DC output end of the main rectifier cabinet is connected to the main battery module; the DC output end of the slave rectifier cabinet is connected to the slave battery module, and the DC bus coupling device is connected between the DC output end of the main rectifier cabinet and the DC output end of the slave rectifier cabinet.

[0040] like Figure 1 、 Figure 2 or Figure 8As shown, the structures of the various power supply devices are the same. In practical applications, any power supply device can be used as the main power supply device, and the other power supply devices can be used as slave power supply devices. Specifically, the main power supply device also includes a main phase-shifting transformer and a main distribution unit, and the slave power supply device also includes a slave phase-shifting transformer and a slave distribution unit. Specifically, for the main power supply device, the AC power is connected to the high-voltage side of the main phase-shifting transformer, the low-voltage side of the main phase-shifting transformer is connected to the AC end of the main rectifier cabinet, the DC output end of the main rectifier cabinet is respectively connected to the main battery module and the main distribution unit, and the DC output ends of the main rectifier cabinet and the slave rectifier cabinet are connected through a DC busbar device. The structural connection relationship of the slave power supply device is the same as that of the main power supply device, and will not be repeated here.

[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, the main power supply device and the slave power supply device are output-coupled, and the main power supply device and the slave power supply device can exchange information during operation. When any mains power supply is abnormally cut off, the other mains power supply can directly achieve power supply continuity for the load through the bus coupling section.

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

[0044] Specifically, the master rectifier cabinet and the slave rectifier cabinet each include a plurality of rectifier modules, and the plurality of rectifier modules are connected in parallel for output.

[0045] See also Figure 3 , which shows a flow chart of the implementation of the master-slave control method of a DC power supply provided by an embodiment of the present invention, the method is applied to the master monitoring unit, and is described in detail as follows:

[0046] S101: Acquire the actual battery current of the main battery module in the current cycle.

[0047] S102: Acquire the actual battery current of the slave battery module in the current cycle collected by the slave monitoring unit.

[0048] In this embodiment, a communication connection is established between the master monitoring unit and the slave monitoring unit. During normal system operation, the master monitoring unit periodically transmits status data of the master power supply to the slave monitoring unit. Upon receiving the status data from the master monitoring unit, the slave monitoring unit transmits its own data to the master monitoring unit.

[0049] Specifically, the control cycle of a single power supply device can be 10ms. If the main power supply device uses communication to collect current data from the power supply device and then performs control, the 10ms control cycle is relatively fast, which will cause data asynchrony. Considering that battery current management belongs to slow-loop control, this embodiment can change the control cycle to 100ms.

[0050] Specifically, the master monitoring unit collects the actual battery current of the master battery module through the Hall current sensor. The slave monitoring unit collects the actual battery current of the slave battery module through the Hall current sensor and sends the actual battery current of the slave battery module to the master monitoring unit.

[0051] S103: Add the actual battery current of the master battery module and the actual battery current of the slave battery module in the current cycle to obtain a sum of the actual battery currents.

[0052] S104: Calculate a preset voltage value for the current cycle based on a difference between the sum of actual battery currents in the current cycle and the sum of preset equalization currents; and control the output voltage of the main rectifier cabinet based on the preset voltage value for the current cycle.

[0053] In this embodiment, the master battery module and the slave battery module are treated as a whole to control the total battery current. Since there is only one control target, this embodiment can simplify the control logic, realize equalization current limiting of the sum of the actual battery currents of the master and slave battery modules, and ensure stable control of the battery current.

[0054] S105: Send the preset voltage value of the current cycle to the slave monitoring unit, so that the slave monitoring unit controls the output voltage of the slave rectifier cabinet based on the preset voltage value.

[0055] In a possible embodiment, the main rectifier cabinet includes multiple rectifier modules; the specific implementation process of S104 includes:

[0056] The preset voltage value is sent to the main rectifier cabinet, so that the main rectifier cabinet performs current sharing control on the corresponding multiple rectifier modules based on the preset voltage value.

[0057] In this embodiment, the actual battery currents of the master and slave battery modules in the current cycle are added together, and the preset voltage value at that time is calculated based on the battery equalization control logic. After obtaining the preset voltage value, the master monitoring unit sends the preset voltage value to the master rectifier cabinet, so that the master rectifier cabinet performs internal current equalization control on its rectifier modules based on the preset voltage value. The master monitoring unit also sends the preset voltage value to the slave monitoring unit, which sends the preset voltage value to the slave rectifier cabinet, which then performs internal current equalization control on its rectifier modules based on the preset voltage value.

[0058] It can be seen from the above embodiments that the embodiments of the present application can control the master and slave power supply devices through the main monitoring unit. Even if the AC power of one power supply device is cut off, the current of other power supply devices can still flow to the output end of the power supply device that has lost power through the DC bus device, thereby ensuring the power supply continuity of all power supply devices. At the same time, the main monitoring unit can timely adjust the output voltage of several other power supply devices with normal AC power according to the sum of the battery currents of each power supply device, thereby further ensuring the power supply reliability on the basis of ensuring the power supply continuity of all power supply devices, and avoiding the problem of system out of control due to AC power failure.

[0059] In one possible embodiment, Figure 4 As shown, Figure 4 The flowchart of the DC power supply provided in this embodiment is shown; the specific implementation process of S104 includes:

[0060] S201: The sum of the preset equalizing currents I bat_ret_t Subtract the actual battery current of the current cycle I bat_fb_t , get the battery current difference;

[0061] S202: Inputting the battery current difference into a first PI controller to obtain a first voltage value of a current cycle;

[0062] S203: Subtract the first voltage value of the current cycle from the preset voltage value of the previous cycle to obtain the preset voltage value U of the current cycle. ret .

[0063] In a possible embodiment, the specific implementation process of S203 includes:

[0064] If the actual battery current of the master battery module in the current cycle is greater than the preset equalization current, or the actual battery current of the slave battery module in the current cycle is greater than the preset equalization current, the actual battery current greater than the preset equalization current is used as the first actual battery current, and the difference between the first actual battery current and the preset equalization current is calculated to obtain the single group current difference;

[0065] Inputting the single-group current difference into a second PI controller to obtain a compensation voltage;

[0066] The preset voltage value of the current cycle is obtained by subtracting the first voltage value and the compensation voltage of the current cycle from the preset voltage value of the previous cycle.

[0067] In this embodiment, since the method provided in this embodiment regards the master battery module and the slave battery module as a whole, when the battery capacity difference between the master and slave battery modules is large, there will be a situation where the charging current of a single battery group is high. Therefore, this embodiment can add the above-mentioned current limiting logic of the single battery group to avoid the situation where the charging current of a single battery group is high.

[0068] In a possible embodiment, after S202, the specific implementation method of S104 further includes:

[0069] The preset voltage value is limited.

[0070] Correspondingly, the output voltage of the main rectifier cabinet is controlled based on the preset voltage value after limiting processing, and the preset voltage value after limiting processing is sent to the slave monitoring unit so that the slave monitoring unit controls the output voltage of the slave rectifier cabinet based on the preset voltage value.

[0071] In a possible embodiment, the DC power supply further includes a first relay; the master monitoring unit and the slave monitoring unit both include an RS485 communication interface and a CAN communication interface;

[0072] The RS485 communication interface of the master monitoring unit is connected to the RS485 communication interface of the slave monitoring unit; the CAN communication interface of the master monitoring unit is connected to the CAN communication interface of the slave monitoring unit through the first relay; the master-slave control method of the DC power supply provided in this embodiment also includes:

[0073] Monitor whether the RS485 communication between the master monitoring unit and the slave monitoring unit fails;

[0074] If the RS485 communication between the master monitoring unit and the slave monitoring unit fails, the first relay is controlled to be closed so that the master monitoring unit is connected to the slave monitoring unit via CAN communication.

[0075] In this embodiment, since this embodiment performs master-slave control between two power supply devices of a DC power supply, one power supply device is required to be a master power supply device and the other power supply device is required to be a slave power supply device. The setting method of the master and slave power supply devices can be set by input switch value setting or touch screen setting. The data acquisition in the two power supply devices is independent. The master monitoring unit needs to have information from the slave power supply device to perform overall control. Therefore, data communication is required between the master monitoring unit and the slave monitoring unit. Currently, a single monitoring unit is provided with 2 RS485 communication interfaces and one CAN communication interface, such as Figure 5 As shown, the RS485A communication interface is used to implement information exchange between the touch screen and the monitoring unit, allowing the touch screen to display the parameters of the power supply unit and the busbar status. The CAN communication interface is used to communicate with the rectifier module, and the RS485B communication interface is used to communicate with the monitoring unit of another power supply unit.

[0076] Specifically, each power supply unit corresponds to a touch screen that communicates with the corresponding monitoring unit via RS485A to display the following: the on / off status of the DC bus coupler, the type of the DC bus coupler, the circuit breaker status of the DC bus coupler (if it is a normally closed circuit breaker), the open and closed modes of the DC bus coupler's circuit breaker, the cabinet number of the power supply unit, and the status of the master and slave power supplies of the DC bus coupler. The open and closed modes of the DC bus coupler's circuit breaker can be automatic or manual.

[0077] Specifically, data communication between the two power supply units can be achieved using either RS485 or CAN lines. However, using CAN lines would connect all rectifier modules between the two rectifier cabinets, doubling the CAN bus occupancy and risking data loss. Therefore, this embodiment prioritizes RS485 communication. Although the RS485B communication interface has a relatively low communication rate, considering that battery current control is a slow-loop control, RS485 communication can meet the control requirements.

[0078] During data transmission between two power supply units, the master monitoring unit transmits data via the RS485B communication interface. The data transmitted includes 12 items: unit status, bus voltage of the bus tie section, actual battery current, preset equalization current, load current, total rectifier module current, number of operating rectifier modules, battery status, system fault status, AC status, slave unit cabinet number, and preset voltage value. RS485B communication uses a baud rate of 9600, a data length of 29 bytes (24 data bytes), and a data transmission time of 30ms. Therefore, the RS485B transmission cycle is set to 50ms. After receiving the corresponding data, the slave monitoring unit sends the corresponding content back to the master monitoring unit and simultaneously sends the preset voltage value to the slave rectifier cabinet via the CAN communication interface. The master monitoring unit cannot continue to transmit the next data transmission until it receives the corresponding information. If the master monitoring unit does not receive the data from the slave monitoring unit within the specified time, it retransmits the data. After six retransmissions without a response frame, the communication is considered failed. If the slave monitoring unit does not receive the query frame from the master monitoring unit within 3 seconds, it is considered a communication failure. If the communication between the two monitoring units fails, the CAN communication backup route is switched to for data transmission.

[0079] In one embodiment, the DC power supply further includes a first relay; the first relay is a normally closed relay; the master monitoring unit and the slave monitoring unit both include an RS485 communication interface and a CAN communication interface;

[0080] The RS485 communication interface of the master monitoring unit is connected to the RS485 communication interface of the slave monitoring unit; the CAN communication interface of the master monitoring unit is connected to the CAN communication interface of the slave monitoring unit through the first relay;

[0081] The dry contact of the RS485 communication interface of the master monitoring unit is connected to one normally closed contact of the first relay, and the dry contact of the RS485 communication interface of the slave monitoring unit is connected to the other normally closed contact of the first relay.

[0082] Specifically, when the RS485 communication interface fails, the dry contact of the RS485 communication interface is disconnected, the first relay is powered off and then closed, and the CAN communication interfaces of the master and slave monitoring units establish a communication connection.

[0083] Furthermore, when the master-slave monitoring unit switches to CAN communication, data transmission continues periodically with a 10ms cycle. The CAN line now connects all rectifier modules in both rectifier cabinets and the master-slave monitoring units. Once CAN communication is switched, the master monitoring unit sends the preset voltage value to the slave rectifier cabinet, while other information is still sent and received by the monitoring units of each power supply unit.

[0084] Because the preset voltage values ​​received by each rectifier module are all sent by the master monitoring unit when using CAN communication, the master monitoring unit cannot distinguish between the master rectifier cabinet and the slave rectifier cabinet. This embodiment can distinguish the rectifier modules of the two power supply units by adding cabinet numbers. Specifically, the rectifier modules of the master power supply unit are not marked with cabinet numbers, while the rectifier modules of the slave power supply unit are marked with cabinet numbers. In this way, when the monitoring unit sends information such as preset voltage values ​​to the rectifier modules, the cabinet numbers are marked on the sent information. Rectifier modules with cabinet numbers only process information with the same cabinet numbers, while rectifier modules without cabinet numbers process information without cabinet numbers. This method achieves current equalization within the cabinets.

[0085] Furthermore, the cabinet number stored inside the rectifier module can be configured on-site when the system is powered on for the first time. After a power supply device is set as a slave power supply device, the slave monitoring unit corresponding to the slave power supply device sends the cabinet number to all rectifier modules in its slave rectifier cabinet, and at the same time queries the cabinet numbers of all rectifier modules in its slave rectifier cabinet. After confirming that the cabinet number is correct, the cabinet number is manually solidified. After solidification, the slave monitoring unit only processes and displays the information of the rectifier module with the cabinet number. The rectifier module with the incorrect cabinet number is determined to be offline. The master monitoring unit only processes and displays the information of the rectifier module without the cabinet number. In this way, the independence of the display information of the master and slave rectifier cabinets is achieved.

[0086] Through the above method, this embodiment can improve the communication reliability between the master and slave power supply devices, and avoid the situation where the overall control is lost due to the failure of communication between the master and slave cabinets.

[0087] In one embodiment of the present application, the DC power supply can also perform battery testing and insulation testing, the specific process of which is as follows:

[0088] 1. Battery test: If the battery tests of the master and slave power supply devices are performed simultaneously, the battery test operation can be performed on the master power supply device. After the battery test is completed, the slave monitoring unit saves the battery capacity value of the battery module calculated by itself and sends it to the master monitoring unit. If a single group of battery tests are performed, the tests are performed separately in each power supply device. Specifically, when the master power supply device performs a battery test, the master power supply device controls the slave power supply device to adjust the voltage; when the slave power supply device performs a battery test, the information of the slave monitoring device sent back to the master monitoring unit by the slave monitoring unit includes a battery test flag. After the master monitoring unit receives the information, it sends back a message indicating that the battery test is ready. After the slave monitoring unit receives the information indicating that the battery test is ready, the slave monitoring unit starts to control the voltage of the two power supply devices. After the battery test is completed, the master-slave logic is swapped again.

[0089] As another testing method, this embodiment may also consider enabling two monitoring units to establish a CAN communication connection during battery testing, with the monitoring unit of the power supply device requiring battery testing acting as the overall control unit.

[0090] 2. Insulation test: Since the master and slave power supply devices are connected in parallel, if both perform insulation testing at the same time, it will cause a conflict. Therefore, insulation testing needs to be performed separately at different times. The master and slave monitoring units each send an insulation testing flag to ensure that only one monitoring unit is performing insulation testing at the same time. The insulation testing switching and calculation maintain the existing logic.

[0091] In addition, the floating charge conversion control and temperature compensation control of the master and slave power supply devices are all executed by the master monitoring unit, and the slave monitoring unit only needs to send the battery temperature of its battery module to the master monitoring unit.

[0092] In one embodiment of the present application, the main monitoring unit can adjust the preset voltage value of the main rectifier cabinet at preset intervals to determine whether current is flowing through the bus tie section. If no current is flowing through the bus tie section, it is determined that the bus tie section fuse has blown. Once the bus tie fuse blows, the system switches to the control logic of independent equalization of charging of the two cabinets.

[0093] Specifically, the independent equalizing charge control logic is as follows:

[0094] For any monitoring device, obtain the actual battery current of the battery module of the monitoring device in the current cycle, subtract the actual battery current from the preset equalization current to obtain the battery current difference, perform PI calculation on the battery current difference to obtain the preset voltage value, and use the preset voltage value to control the output voltage of the rectifier cabinet of the monitoring device.

[0095] As can be seen from the above embodiment, the master-slave control method for a DC power supply provided in this embodiment offers a relatively simple control approach. The master and slave power supply devices are considered as a whole, and the control target (the sum of the preset equalization currents) is also relatively clear, ensuring that the total current of the two battery groups does not exceed the equalization current point. Furthermore, since the control method provided in this embodiment has only one control target, the battery current can be controlled more stably. In steady state, the battery current ripple is only related to the output ripple.

[0096] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order 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.

[0097] 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.

[0098] Figure 6 A schematic diagram of the structure of a master-slave control device for a DC power supply provided by an embodiment of the present invention is shown. The master-slave control device for a DC power supply is applied to the master monitoring unit. For ease of illustration, only the parts related to the embodiment of the present invention are shown, which are described in detail as follows:

[0099] like Figure 6 As shown, the master-slave control device 100 of a DC power supply includes:

[0100] A main battery current acquisition module 110 is used to obtain the actual battery current of the main battery module in the current cycle;

[0101] A slave battery current acquisition module 120, configured to acquire the actual battery current of the slave battery module in the current cycle collected by the slave monitoring unit;

[0102] a battery current summing module 130 , configured to add the actual battery current of the master battery module and the actual battery current of the slave battery module in a current cycle to obtain a sum of the actual battery currents;

[0103] The main voltage control module 140 is configured to calculate a preset voltage value for the current cycle based on the difference between the sum of the actual battery currents in the current cycle and the sum of the preset equalization currents; and to control the output voltage of the main rectifier cabinet based on the preset voltage value for the current cycle;

[0104] The slave voltage control module 150 is configured to send the preset voltage value of the current cycle to the slave monitoring unit, so that the slave monitoring unit controls the output voltage of the slave rectifier cabinet based on the preset voltage value.

[0105] In one embodiment, the main voltage control module 140 includes:

[0106] a difference calculation unit, configured to subtract the sum of the actual battery currents in the current cycle from the sum of the preset equalization currents to obtain a battery current difference;

[0107] a first voltage value calculation unit, configured to input the battery current difference into a first PI controller to obtain a first voltage value of a current cycle;

[0108] The preset voltage value calculation unit is used to subtract the first voltage value of the current cycle from the preset voltage value of the previous cycle to obtain the preset voltage value of the current cycle.

[0109] In a possible embodiment, the preset voltage value calculation unit includes:

[0110] If the actual battery current of the master battery module in the current cycle is greater than the preset equalization current, or the actual battery current of the slave battery module in the current cycle is greater than the preset equalization current, the actual battery current greater than the preset equalization current is used as the first actual battery current, and the difference between the first actual battery current and the preset equalization current is calculated to obtain the single group current difference;

[0111] Inputting the single-group current difference into a second PI controller to obtain a compensation voltage;

[0112] The preset voltage value of the current cycle is obtained by subtracting the first voltage value and the compensation voltage of the current cycle from the preset voltage value of the previous cycle.

[0113] In one embodiment, the master-slave control device 100 of the DC power supply further includes a limiting module for:

[0114] The preset voltage value is limited.

[0115] In one embodiment, the DC power supply further includes a first relay; the master monitoring unit and the slave monitoring unit both include an RS485 communication interface and a CAN communication interface;

[0116] The RS485 communication interface of the master monitoring unit is connected to the RS485 communication interface of the slave monitoring unit; the CAN communication interface of the master monitoring unit is connected to the CAN communication interface of the slave monitoring unit through the first relay;

[0117] The master-slave control device 100 of the DC power supply further includes a communication switching module for:

[0118] Monitor whether the RS485 communication between the master monitoring unit and the slave monitoring unit fails;

[0119] If the RS485 communication between the master monitoring unit and the slave monitoring unit fails, the first relay is controlled to be closed so that the master monitoring unit is connected to the slave monitoring unit via CAN communication.

[0120] The master-slave control device for a DC power supply provided in this embodiment can be used to execute the above-mentioned master-slave control method embodiment for a DC power supply. Its implementation principle and technical effects are similar and will not be described in detail in this embodiment.

[0121] Figure 7 FIG is a schematic diagram of a main monitoring unit provided by an embodiment of the present invention. Figure 7 As shown, the master 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 in the above-mentioned master-slave control method embodiments of the 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.

[0122] 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 main monitoring unit 7.

[0123] The main monitoring unit 7 can be a computing device such as a desktop computer, a notebook, a palmtop computer, a cloud server, etc. The main monitoring unit 7 can include, but is not limited to, a processor 70 and a memory 71. It can be understood by those skilled in the art that Figure 7 It is only an example of the main monitoring unit 7 and does not constitute a limitation of the main 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 main monitoring unit may also include input and output devices, network access devices, buses, etc.

[0124] 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.

[0125] The memory 71 can be an internal storage unit of the main monitoring unit 7, such as a hard disk or memory of the main monitoring unit 7. The memory 71 can also be an external storage device of the main monitoring unit 7, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the main monitoring unit 7. Furthermore, the memory 71 can also include both the internal storage unit of the main 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 main monitoring unit. The memory 71 can also be used to temporarily store data that has been output or is about to be output.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] In the embodiments provided by the present invention, it should be understood that the disclosed device / main monitoring unit and method can be implemented in other ways. For example, the device / main monitoring unit embodiment described above is 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 interface, indirect coupling or communication connection of the device or unit, which can be electrical, mechanical or other forms.

[0130] 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.

[0131] 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.

[0132] 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 master-slave 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 may include: any entity or device capable of carrying 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.

[0133] 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 master-slave control method for a DC power supply, characterized in that: The DC power supply includes a DC busbar device, a main power supply device and at least one slave power supply device, wherein the main power supply device includes a main rectifier cabinet, a main battery module and a main monitoring unit; the slave power supply device includes a slave rectifier cabinet, a slave battery module and a slave monitoring unit; The DC output end of the master rectifier cabinet is connected to the master battery module; the DC output end of the slave rectifier cabinet is connected to the slave battery module, and the DC bus coupling device is connected between the DC output end of the master rectifier cabinet and the DC output end of the slave rectifier cabinet; The method is applied to the main monitoring unit and includes: Obtaining the actual battery current of the main battery module in the current cycle; Acquiring an actual battery current of the slave battery module in a current cycle collected by the slave monitoring unit; Adding the actual battery current of the master battery module and the actual battery current of the slave battery module in the current cycle to obtain a sum of the actual battery currents; Calculating a preset voltage value for the current cycle based on the difference between the sum of the actual battery currents in the current cycle and the sum of the preset equalization currents; and controlling the output voltage of the main rectifier cabinet based on the preset voltage value for the current cycle; Sending the preset voltage value of the current cycle to the slave monitoring unit, so that the slave monitoring unit controls the output voltage of the slave rectifier cabinet based on the preset voltage value; The calculating of the preset voltage value of the current cycle based on the difference between the sum of the actual battery currents of the current cycle and the sum of the preset equalization charging currents includes: Subtracting the sum of the actual battery currents in the current cycle from the sum of the preset equalization currents to obtain a battery current difference; Inputting the battery current difference into a first PI controller to obtain a first voltage value of the current cycle; The preset voltage value of the current cycle is obtained by subtracting the first voltage value of the current cycle from the preset voltage value of the previous cycle.

2. The master-slave control method of a DC power supply according to claim 1, characterized in that: The step of subtracting the first voltage value of the current cycle from the preset voltage value of the previous cycle to obtain the preset voltage value of the current cycle includes: If the actual battery current of the master battery module in the current cycle is greater than the preset equalization current, or the actual battery current of the slave battery module in the current cycle is greater than the preset equalization current, the actual battery current greater than the preset equalization current is used as the first actual battery current, and the difference between the first actual battery current and the preset equalization current is calculated to obtain the single group current difference; Inputting the single-group current difference into a second PI controller to obtain a compensation voltage; The preset voltage value of the current cycle is obtained by subtracting the first voltage value and the compensation voltage of the current cycle from the preset voltage value of the previous cycle.

3. The master-slave control method of a DC power supply according to claim 1 or 2, characterized in that: After obtaining the preset voltage value of the current cycle, the method further includes: The preset voltage value is limited.

4. The master-slave control method of a DC power supply according to claim 1, wherein: The DC power supply also includes a first relay; the master monitoring unit and the slave monitoring unit both include an RS485 communication interface and a CAN communication interface; The RS485 communication interface of the master monitoring unit is connected to the RS485 communication interface of the slave monitoring unit; the CAN communication interface of the master monitoring unit is connected to the CAN communication interface of the slave monitoring unit through the first relay; The method further comprises: Monitor whether the RS485 communication between the master monitoring unit and the slave monitoring unit fails; If the RS485 communication between the master monitoring unit and the slave monitoring unit fails, the first relay is controlled to be closed so that the master monitoring unit is connected to the slave monitoring unit via CAN communication.

5. A master-slave control device for a DC power supply, characterized in that: The DC power supply includes a DC busbar device, a main power supply device and at least one slave power supply device, wherein the main power supply device includes a main rectifier cabinet, a main battery module and a main monitoring unit; the slave power supply device includes a slave rectifier cabinet, a slave battery module and a slave monitoring unit; The DC output end of the master rectifier cabinet is connected to the master battery module; the DC output end of the slave rectifier cabinet is connected to the slave battery module, and the DC bus coupling device is connected between the DC output end of the master rectifier cabinet and the DC output end of the slave rectifier cabinet; The master-slave control device of the DC power supply is applied to the master monitoring unit and includes: A main battery current acquisition module, used to obtain the actual battery current of the main battery module in the current cycle; A slave battery current acquisition module, configured to acquire the actual battery current of the slave battery module in the current cycle collected by the slave monitoring unit; a battery current summing module, configured to add the actual battery current of the master battery module and the actual battery current of the slave battery module in a current cycle to obtain a sum of the actual battery currents; A main voltage control module, configured to calculate a preset voltage value for the current cycle based on the difference between the sum of the actual battery currents in the current cycle and the sum of the preset equalization currents; and to control the output voltage of the main rectifier cabinet based on the preset voltage value for the current cycle; A slave voltage control module, configured to send the preset voltage value of the current cycle to the slave monitoring unit, so that the slave monitoring unit controls the output voltage of the slave rectifier cabinet based on the preset voltage value; The main voltage control module is used for: Subtracting the sum of the actual battery currents in the current cycle from the sum of the preset equalization currents to obtain a battery current difference; Inputting the battery current difference into a first PI controller to obtain a first voltage value of the current cycle; The preset voltage value of the current cycle is obtained by subtracting the first voltage value of the current cycle from the preset voltage value of the previous cycle.

6. A main monitoring unit, characterized in that: The method comprises a processor and a memory, 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 execute 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, a master power supply device, and at least one slave power supply device, wherein the master power supply device includes a master rectifier cabinet, a master battery module, and a master monitoring unit according to claim 5; and the slave power supply device includes a slave rectifier cabinet, a slave battery module, and a slave monitoring unit. The DC output end of the main rectifier cabinet is connected to the main battery module; the DC output end of the slave rectifier cabinet is connected to the slave battery module, and the DC bus coupling device is connected between the DC output end of the main rectifier cabinet and the DC output end of the slave rectifier cabinet.

9. The DC power supply according to claim 8, wherein: The DC power supply further includes a first relay; the master monitoring unit and the slave monitoring unit both include an RS485 communication interface and a CAN communication interface; the first relay is a normally closed relay; The RS485 communication interface of the master monitoring unit is connected to the RS485 communication interface of the slave monitoring unit; the CAN communication interface of the master monitoring unit is connected to the CAN communication interface of the slave monitoring unit through the first relay; The dry contact of the RS485 communication interface of the master monitoring unit is connected to one normally closed contact of the first relay, and the dry contact of the RS485 communication interface of the slave monitoring unit is connected to the other normally closed contact of the first relay.

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