Current sharing control method and device for charging module parallel operation system

Abstract

The invention provides a current-sharing control method and a current-sharing control device for a charging module parallel system, which can simplify software and hardware design of the system and realize current-sharing control in a simpler and more reliable way, and the charging module parallel system comprises a plurality of charging modules which are connected in parallel. Comprising the following steps: detecting whether the charging module parallel operation system meets the condition that at least two charging modules are started or not; if yes, detecting whether a current sharing starting condition is met, and if yes, starting current sharing; otherwise, current sharing is not started; obtaining the number of charging modules needing current sharing and current sharing adjustment data of the charging modules, and generating an adjustment quantity to modify a reference control voltage in combination with the current sharing adjustment data and the number of the charging modules needing current sharing; and in combination with the current-sharing regulation data and the number of the charging modules needing current sharing, generating a regulation variable to modify a given voltage value of the voltage loop, and realizing current sharing by modifying the reference control voltage and the given voltage value of the voltage loop at the same time.

Description

Technical Field

[0001] The present invention belongs to the technical field of charging module control in a charging pile, and relates to a current sharing control method and device for a charging module parallel system. Background Art

[0002] With the guidance of national policies and the general trend of social development, the new energy industry has gradually become hot. With the gradual increase in new energy vehicles and the explosive growth of charging piles, AC-DC converter charging modules have also become a hot topic.

[0003] In high-power occasions such as new energy vehicles, a single charging module power supply cannot meet the load power requirements, so it is necessary to consider connecting charging modules in parallel. Multiple charging modules in parallel can form a charging module parallel system. The first problem to be solved in parallel charging modules is the current sharing problem. Current sharing can ensure the uniform distribution of current stress and thermal stress between modules, prevent one or more modules from operating in the current limit state, and reduce the reliability of the system.

[0004] Existing current sharing methods include impedance matching method and master-slave allocation method. Impedance matching method is to achieve the purpose of approximate current sharing by adjusting the output impedance of the module, which requires modifying the internal resistance. The master-slave allocation method selects one module as the master module and the remaining modules as slave modules. The voltage regulator of the master module is used to control the voltage adjustment value of the remaining parallel modules to ensure that the output voltage is consistent, so as to be consistent with the current of the master module to achieve current sharing. The master-slave allocation method requires the master module to send multiple frames of commands for adjustment, and its hardware design and software implementation are relatively complex. Summary of the invention

[0005] In view of the above problems, the present invention provides a current sharing control method and device for a charging module parallel system, which can simplify the software and hardware design of the system and realize current sharing control in a simpler and more reliable manner.

[0006] The technical solution is as follows: a current sharing control method for a charging module parallel system, wherein the charging module parallel system comprises a plurality of charging modules connected in parallel, and is characterized in that it comprises the following steps:

[0007] Check whether the charging module parallel system meets the requirement that at least two charging modules are enabled;

[0008] If it is satisfied, check whether the conditions for starting current sharing are met. If so, start current sharing; otherwise, do not start current sharing;

[0009] Obtain the number of charging modules that require current sharing and the current sharing adjustment data of the charging modules, and generate an adjustment amount to modify the reference control voltage based on the obtained current sharing adjustment data; combine the current sharing adjustment data and the number of charging modules that require current sharing to generate an adjustment amount to modify the given voltage value of the voltage loop, and achieve current sharing by simultaneously modifying the reference control voltage and the given voltage value of the voltage loop.

[0010] Furthermore, the detection of whether the conditions for starting current sharing are met includes: detecting whether the current value in the parallel system is greater than a detection threshold; if so, determining whether the charging module itself is faulty; if not, starting current sharing; otherwise, not starting current sharing.

[0011] Furthermore, after detecting that the current value in the parallel system is greater than the detection threshold, the parallel system is first waited for to be stable, and then it is determined whether the charging module itself is faulty.

[0012] Furthermore, the reference control voltage is modified as follows: the current sharing adjustment data obtained includes the maximum current, the minimum current and the current output current value, and the average current is calculated based on the number of charging modules that need current sharing. The error value between the maximum current and the minimum current and the average current are used to determine whether the charging module needs current sharing. If current sharing is required, the required adjustment amount is calculated based on the difference between the current output current and the average current, and the adjustment amount is added to the reference control voltage for adjustment.

[0013] Furthermore, when modifying the reference control voltage, if the error between the maximum current and the minimum current is greater than 0.5A and the average current is greater than 1A, it is considered that the charging module needs current sharing; if the difference between the average current and the current output current of the charging module is greater than 0.2A, the adjustment amount is increased by 1, and if it is less than 0.2A, the adjustment amount is reduced by 1. The adjustment amount is a digital value corresponding to the voltage value.

[0014] Furthermore, modifying the voltage loop given voltage is specifically performed as follows: based on obtaining an error value according to the difference between the output current and the average current, the error value is multiplied by a coefficient and then accumulated to obtain an integral adjustment amount, and the integral adjustment amount is added to the voltage loop given voltage amount for adjustment.

[0015] Furthermore, the charging modules send and receive data information via CAN communication.

[0016] A computer device includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the current sharing control method for a charging module parallel system as described above is implemented.

[0017] A computer-readable storage medium stores a program, which, when executed by a processor, implements the current sharing control method for a charging module parallel system as described above.

[0018] A computer program product comprises a computer program / instruction, which implements the steps of the above method when executed by a processor.

[0019] The current sharing control method for the charging module parallel system of the present invention can realize current sharing control through software algorithm without hardware adjustment. In the present invention, the reference control voltage and the voltage loop given voltage value are modified simultaneously to perform current sharing. The change of the reference control voltage directly leads to the change of the output voltage of the charging module to achieve the same output current level as other charging modules. The voltage loop is the part of the charging module responsible for stabilizing the output voltage. By modifying the voltage loop given voltage value, the output voltage can be accurately controlled to ensure the stability and accuracy of the current sharing. The present invention introduces integral control, which can smoothly pull the output current to the average value and keep it stable after reaching it, avoiding oscillation and jump. By combining the reference control voltage and the voltage loop given voltage value adjustment strategy, it can not only quickly respond to the current difference between the modules, but also ensure that there will be no oscillation after the system reaches a steady state, thereby ensuring the consistency and stability of the output current. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the steps of the current sharing control method for the charging module parallel system in the embodiment;

[0021] Figure 2 This is a schematic diagram of a charging module parallel system;

[0022] Figure 3 is a flow chart of a current sharing control method for a charging module parallel system in an embodiment;

[0023] Figure 4 FIG. 4 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0024] See Figure 1 The present invention provides a current balancing control method for a charging module parallel system. The charging module parallel system includes multiple charging modules connected in parallel. The purpose of current balancing is to make the output current of multiple charging modules working in parallel as close to the average value as possible to avoid overloading some modules and underloading other modules. In order to achieve this goal, the output current of each module needs to be adjusted, and the current adjustment can be achieved by adjusting the output voltage of the module.

[0025] Specifically, in one embodiment of the present invention, based on the CAN communication of the charging module, all modules in the system only need to broadcast a frame of their own data information at regular intervals, and each charging module will receive data information from other charging modules in the system. Then, the charging module obtains the compensation amount through the current sharing algorithm to realize the optimal control strategy. The current sharing control method may include the following steps:

[0026] Step S1: Detect whether the charging module parallel system satisfies the requirement that at least two charging modules are enabled. When only one charging module is working, current sharing is not enabled.

[0027] Step S2: If the condition is met, detect whether the current sharing start condition is met. If so, start the current sharing; otherwise, do not start the current sharing;

[0028] Step S3: Obtain the number of charging modules that need current sharing and the current sharing adjustment data of the charging modules, and generate an adjustment amount to modify the reference control voltage in combination with the current sharing adjustment data and the number of charging modules that need current sharing; generate an adjustment amount to modify the given voltage value of the voltage loop in combination with the current sharing adjustment data and the number of charging modules that need current sharing, and achieve current sharing by simultaneously modifying the reference control voltage and the given voltage value of the voltage loop.

[0029] The reference control voltage is a key parameter that determines the output voltage of the charging module and directly affects the output voltage of the module. By modifying the reference control voltage, the output voltage of the module can be adjusted, thereby adjusting the output current. Modifying the reference control voltage can quickly respond to current changes and achieve instant current sharing regulation.

[0030] If the reference control voltage is simply modified, there will be a trend of current sharing in the overall direction. The output current of all charging modules participating in current sharing will be closer and closer to the average value. However, when the average current value is reached, it cannot be stabilized and cannot reach a steady state, and oscillation jumps will occur. This requires the introduction of a modified voltage loop given algorithm to achieve a steady state through integration. The voltage loop is the part of the charging module responsible for stabilizing the output voltage. By modifying the given voltage value of the voltage loop, the current sharing effect can be further optimized, system oscillation can be avoided, and stability can be improved.

[0031] like Figure 2 A charging module parallel system is shown, which has four charging modules with addresses 1, 2, 3, and 4. The charging modules are connected in parallel and connected to the same CAN bus. The modules send their own information to other charging modules through broadcast commands. After the charging module is powered on, it will actively report a frame of its own information every 300ms. The content of the information frame includes the module address, fault status, current equalization adjustment amount, output current, etc. At the same time, it will also receive its own information frames sent by other charging modules, and transfer these data to its own RAM area array as the data source of the current equalization algorithm.

[0032] See Figure 3 , the charging module parallel system can perform the current sharing control method as follows:

[0033] Step 1: System startup. If only one charging module is working in the parallel system, current sharing control is not enabled. If there are more than two charging modules working, go to step 2.

[0034] Step 2: Detect whether the conditions for starting current sharing are met. If so, start current sharing; otherwise, do not start current sharing. In step 2, detecting whether the conditions for starting current sharing are met includes: detecting whether the current value in the parallel system is greater than the detection threshold. The detection threshold in the embodiment is 1A, and it can also be adjusted to 2A or a lower 0.8A, etc. When it is detected that the current is greater than 1A, first wait for the parallel system to stabilize. The waiting time in the embodiment is 10S, which can be adjusted according to the system situation, and can also be adjusted to 15s or a lower 5S, etc., and then determine whether the charging module itself is faulty. The fault status comes from the information reported by the charging module itself through CAN communication. If it is satisfied, determine whether the charging module itself is faulty. If there is no fault, start current sharing; otherwise, do not start current sharing.

[0035] Step S3: traverse and determine the number of non-faulty charging modules in the system, obtain the number of charging modules that need current sharing and current sharing adjustment data, and generate an adjustment amount to modify the reference control voltage;

[0036] Modifying the reference control voltage is specifically performed as follows: the current sharing adjustment data obtained includes the maximum current, minimum current and current output current value of all charging modules. After traversing the number of fault-free modules in the system, the total current and the number of modules that need current sharing can be obtained. The total current is divided by the number of modules that need current sharing to obtain the average current. The error value between the maximum current and the minimum current and the average current are used to determine whether the charging module needs current sharing. If current sharing is required, the required adjustment amount is calculated based on the difference between the current output current and the average current, and the adjustment amount is added to the reference control voltage for adjustment.

[0037] In the embodiment, when modifying the reference control voltage, if the error value between the maximum current and the minimum current is greater than 0.5A and the average current is greater than 1A, it is considered that the charging module needs current sharing. If current sharing is required, the current sharing adjustment data is used to determine whether the current charging module reference control voltage is increased, decreased or maintained. In the embodiment, if the difference between the average current and the current charging module output current is greater than 0.2A, the adjustment amount is increased by 1, and if it is less than 0.2A, the adjustment amount is reduced by 1. The digital value corresponding to the voltage value of the adjustment amount, the adjustment amount +1 is not the voltage value directly +1V, the +1 here is a digital value, for example, the analog value 600V corresponds to the digital value 1800 in the MCU, and the +1 here is 1800 plus 1, which is 1801. In the final control operation, it will be regulated towards the target value 1801, and the output voltage of 600V will be raised a little.

[0038] Finally, the adjustment amount is added to the reference control voltage amount and brought into the system model for adjustment, which directly acts on the control loop of the charging module with a fast response speed.

[0039] Modifying the given voltage of the voltage loop is performed as follows: Based on the difference between the output current and the average current, the error value is obtained, multiplied by the coefficient and accumulated to obtain the integral adjustment amount, and the integral adjustment amount is added to the given voltage of the voltage loop for adjustment. The following formula can be used as a reference:

[0040]

[0041] Among them, ΔV is the integral adjustment amount, K is the adjustable coefficient, I avgi is the average current, I Outi is the output current of the current charging module, i represents the number of times, and the timer is set to execute once every certain period of time. When the conditions are met, the integral adjustment amount is accumulated and updated;

[0042] Current sharing is achieved by simultaneously modifying the reference control voltage and the voltage loop given voltage value.

[0043] In step S3, on the basis of modifying the reference control voltage, integral regulation is introduced to accumulate the error and gradually eliminate the deviation between the output current and the average current. The integral regulation of the given voltage of the voltage loop can make the system stable after reaching the average current and avoid oscillation caused by rapid regulation. The integral regulation amount is applied to the given voltage value of the voltage loop. By modifying the given voltage value of the voltage loop, long-term stable current sharing control is achieved, and the output voltage is further optimized to ensure that the output current is stable near the average value.

[0044] Traditional methods such as impedance matching and master-slave allocation may require complex hardware adjustments or frequent command interactions, increasing the complexity and failure rate of the system. The current sharing control in the embodiment avoids the need for complex hardware modifications, does not require adjustment of internal resistance, and relies on a master module to send multiple frames of commands to adjust the working status of other modules. In the embodiment, each module only needs to automatically report a frame of its own data at a fixed time, and current sharing control can be achieved through software algorithms, which simplifies the hardware design. By modifying the reference control voltage in combination with modifying the voltage loop given voltage, it can quickly respond to current differences between modules, and ensure that there will be no oscillation after the system reaches a steady state, thereby ensuring the consistency and stability of the output current;

[0045] In the embodiment, each charging module can adjust itself according to the status of itself and other charging modules, thereby enhancing the fault tolerance of the system. Even if a charging module fails, the remaining modules can continue to operate efficiently and can adapt to the configuration of charging stations of different sizes. Real-time data exchange is performed through CAN communication, and real-time adjustment is performed in combination with the current sharing algorithm, thereby improving the real-time and accuracy of current sharing control.

[0046] In an embodiment of the present invention, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the current sharing control method for a charging module parallel system as described above is implemented.

[0047] The computer device may be a terminal, and its internal structure diagram may be as follows: Figure 4 As shown. The computer device includes a processor, a memory, a network interface, a display screen and an input device connected by a bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a current sharing control method for a charging module parallel system is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covering the display screen, or a key, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse, etc.

[0048] The memory may be, but is not limited to, a random access memory (RAM), a read only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), etc. The memory is used to store programs, and the processor executes the programs after receiving the execution instruction.

[0049] The processor can be an integrated circuit chip with signal processing capabilities. The above-mentioned processor can be a general-purpose processor, including a central processing unit (Central Processing Unit, referred to as: CPU), a network processor (Network Processor, referred to as: NP), etc. The processor can also be other general-purpose processors, digital signal processors (Digital Signal Processor, DSP), application-specific integrated circuits (Application Specific Integrated Circuit, ASIC), field programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc. The various methods, steps and logic block diagrams disclosed in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0050] Those skilled in the art will understand that Figure 4 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0051] In an embodiment of the present invention, a computer-readable storage medium is further provided, on which a program is stored, characterized in that when the program is executed by a processor, the current sharing control method for a charging module parallel system as described above is implemented.

[0052] Those skilled in the art will appreciate that the embodiments of the embodiments of the present invention may be provided as methods, computer devices, or computer program products. Therefore, the embodiments of the present invention may take the form of complete hardware embodiments, complete software embodiments, or embodiments combining software and hardware. Moreover, the embodiments of the present invention may take the form of computer program products implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0053] The embodiments of the present invention are described with reference to flowcharts and / or block diagrams of methods, computer devices, or computer program products according to the embodiments of the present invention. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal device generate a device for implementing the functions specified in the flowcharts and / or.

[0054] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in the flowchart.

[0055] In an embodiment of the present invention, a computer program product is further provided, comprising a computer program / instruction, wherein the computer program / instruction implements the steps of the above method when executed by a processor.

[0056] In actual application, the above-mentioned computer program products include but are not limited to: charging stations, charging piles, new energy vehicles, smart phones, desktop computers, laptops, tablet computers, host computers and server platforms, etc., and no specific restrictions are made here.

[0057] The above is a detailed introduction to the current sharing control method, computer device, computer-readable storage medium, and computer program product for the charging module parallel system provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for general technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A current sharing control method for a charging module parallel system, wherein the charging module parallel system comprises a plurality of charging modules connected in parallel, characterized in that: The following steps are involved: Check whether the charging module parallel system meets the requirement that at least two charging modules are enabled; If it is satisfied, check whether the conditions for starting current sharing are met. If so, start current sharing; Otherwise, current sharing will not be started; Obtain the number of charging modules that need current sharing and the current sharing adjustment data of the charging modules, and generate an adjustment amount to modify the reference control voltage by combining the current sharing adjustment data and the number of charging modules that need current sharing; Combining the current sharing adjustment data and the number of charging modules that need current sharing, an adjustment amount is generated to modify the given voltage value of the voltage loop, and current sharing is achieved by simultaneously modifying the reference control voltage and the given voltage value of the voltage loop.

2. A current sharing control method for a charging module parallel system according to claim 1, characterized in that: The detection of whether the conditions for starting current sharing are met includes: detecting whether the current value in the parallel system is greater than a detection threshold, and if so, determining whether the charging module itself is faulty, and if not, starting current sharing; otherwise, not starting current sharing.

3. A current sharing control method for a charging module parallel system according to claim 2, characterized in that: After detecting that the current value in the parallel system is greater than the detection threshold, the parallel system is first waited for to be stable, and then it is determined whether the charging module itself is faulty.

4. The current sharing control method for a charging module parallel system according to claim 1, characterized in that: Modifying the reference control voltage is specifically performed as follows: the current sharing adjustment data obtained includes the maximum current, the minimum current and the current output current value. The average current is calculated based on the number of charging modules that need current sharing. The error value between the maximum current and the minimum current and the average current are used to determine whether the charging module needs current sharing. If current sharing is required, the required adjustment amount is calculated based on the difference between the current output current and the average current, and the adjustment amount is added to the reference control voltage for adjustment.

5. A current sharing control method for a charging module parallel system according to claim 4, characterized in that: When modifying the reference control voltage, if the error between the maximum current and the minimum current is greater than 0.5A and the average current is greater than 1A, it is considered that the charging module needs current sharing; if the difference between the average current and the current charging module output current is greater than 0.2A, the adjustment amount is increased by 1, and if it is less than 0.2A, the adjustment amount is reduced by 1. The adjustment amount is a digital value corresponding to the voltage value.

6. A current sharing control method for a charging module parallel system according to claim 1, characterized in that: Modifying the voltage loop given voltage is specifically performed as follows: based on obtaining an error value according to the difference between the output current and the average current, the error value is multiplied by a coefficient and then accumulated to obtain an integral adjustment amount, and the integral adjustment amount is added to the voltage loop given voltage amount for adjustment.

7. A current sharing control method for a charging module parallel system according to claim 1, characterized in that: The charging modules send and receive data information via CAN communication.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the current sharing control method for a charging module parallel system as claimed in claim 1 is implemented.

9. A computer-readable storage medium having a program stored thereon, characterized in that: When the program is executed by the processor, the current sharing control method for the charging module parallel system as claimed in claim 1 is implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the method according to claim 1 are implemented.

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