Current control method, device and equipment of multi-path parallel converter and storage medium

Abstract

The invention relates to the technical field of converters, and provides a current control method and device for a multi-path parallel converter, equipment and a storage medium. The method comprises the steps that only one current sensor is deployed, the voltage and current of one branch of the multi-path parallel converter at the first moment are collected, the equipment production cost is reduced, the equipment size and weight are reduced, and the influence of factors such as production errors of multiple devices on the control precision is reduced; and determining the actual duty ratio of the branch at the first moment based on the voltage and current of the branch at the first moment, compensating the actual duty ratio of the branch at the first moment to obtain the actual duty ratio of each other branch in the multi-path parallel converter at the second moment, and adjusting the phase current of the corresponding branch according to each actual duty ratio. The voltage parameters are utilized to control the phase current sharing of each branch in the multi-path parallel converter, so that control loops are reduced, the controller design and the control mode are relatively simple, and the stability and the accuracy of the current sharing control precision are ensured.

Description

Background Art

[0002] Due to sudden factors such as overhead line failure, pantograph failure, natural disasters, etc., rail transit trains may be forced to stop due to external power outages and unable to be tractioned. In this case, batteries are generally used for emergency traction. Due to the low voltage characteristics of the battery itself and the high power, harsh working environment and complex working conditions of rail transit vehicles, it is necessary to use a DCDC converter (DC-DC converter) to increase the voltage level of the battery before outputting it to the traction system of the rail transit vehicle.

[0003] In order to reduce the current stress of the device, a multi-way parallel design is generally used in the converter to achieve multi-way equalization of the output power. However, when the branches in the converter are connected in parallel, their characteristics and parameters will be affected by the production process and system errors. In actual operation, they will also be affected by load changes, manufacturing errors or some accidental control errors, resulting in phase current imbalance in one or several branches of the converter, resulting in large differences in the pressure of each branch, which may damage the device and converter.

[0004] To address the problem of unbalanced phase current in each branch of a multi-channel parallel converter, the traditional method is to set a current sensor in each branch to monitor the current of each branch in real time, and use a voltage and current dual closed-loop control algorithm to ensure current sharing in multiple parallel branches.

[0005] However, the above method requires the deployment of multiple current sensors to collect the current values ​​of each phase, which increases the equipment production cost and equipment volume, and is difficult to apply to low-cost application scenarios and small space application scenarios. In addition, the accuracy of current balancing control is affected by the accuracy of the current sensor, and the stability and accuracy of the current balancing control accuracy cannot be guaranteed. Summary of the invention

[0006] The embodiments of the present application provide a current control method, device, equipment and storage medium for a multi-channel parallel converter, which solve the problems of low precision, poor stability, high cost and large size in current sharing control of the multi-channel parallel converter.

[0007] In a first aspect, an embodiment of the present application provides a current control method for a multi-channel parallel converter, comprising:

[0008] Collecting a voltage and current of a branch of the multi-channel parallel converter at a first moment, and determining an actual duty cycle of the branch at the first moment based on the voltage and current of the branch at the first moment;

[0009] By compensating the actual duty cycle of the one branch at the first moment, the actual duty cycles of the other branches in the multi-channel parallel converter at the second moment are obtained, and the phase currents of the corresponding branches are adjusted according to the actual duty cycles.

[0010] Optionally, determining an actual duty cycle of the branch at the first moment based on the voltage and current of the branch at the first moment includes:

[0011] Performing voltage loop control on a voltage difference between a voltage command and an output voltage of the one branch at a first moment to generate a current command;

[0012] Performing current loop control on a current difference between a current command and a phase current of the one branch at a first moment to generate an initial duty cycle of the one branch at the first moment;

[0013] The duty cycle compensation amount obtained by the feedforward control is superimposed on the initial duty cycle of the one branch at the first moment to obtain the actual duty cycle of the one branch at the first moment.

[0014] Optionally, actual duty cycles of other branches in the multi-channel parallel converter at the second moment are obtained by compensating for an actual duty cycle of the one branch at the first moment, wherein the following operations are performed for one other branch:

[0015] Performing voltage loop control on the voltage difference between the output voltage of the one branch at the second moment and the output voltage of the other branch at the second moment to obtain a duty cycle compensation amount of the other branch at the second moment;

[0016] The duty cycle compensation amount of the other branch at the second moment is superimposed on the actual duty cycle of the branch at the first moment to obtain the actual duty cycle of the other branch at the second moment.

[0017] Optionally, collecting the voltage and current of a branch of the multi-channel parallel converter at a first moment includes:

[0018] The voltage and current of the one branch at the first moment are collected in real time by a current sensor arranged on the one branch of the multi-channel parallel converter.

[0019] Optionally, after collecting the voltage and current of a branch of the multi-channel parallel converter at the first moment, the method further includes:

[0020] Obtaining a system current of the multi-channel parallel converter based on the phase current of the one branch at the third moment and the total number of branches of the multi-channel parallel converter;

[0021] Based on the system current of the multi-channel parallel converter and the output voltage of the one branch at the third moment, obtaining the output power of the multi-channel parallel converter;

[0022] When the output power is greater than the system set value, it is determined that the multi-channel parallel converter enters an abnormal operation state, and the operation mode of the multi-channel parallel converter is adjusted.

[0023] In a second aspect, an embodiment of the present application further provides a current control device for a multi-channel parallel converter, comprising:

[0024] A duty cycle generating unit, used for collecting the voltage and current of a branch of the multi-channel parallel converter at a first moment, and determining the actual duty cycle of the branch at the first moment based on the voltage and current of the branch at the first moment;

[0025] By compensating the actual duty cycle of the one branch at the first moment, the actual duty cycle of each other branch in the multi-channel parallel converter at the second moment is obtained;

[0026] The current sharing adjustment unit is used to adjust the phase current of the corresponding branch according to each actual duty cycle.

[0027] Optionally, the duty cycle generating unit is used for:

[0028] Performing voltage loop control on a voltage difference between a voltage command and an output voltage of the one branch at a first moment to generate a current command;

[0029] Performing current loop control on a current difference between a current command and a phase current of the one branch at a first moment to generate an initial duty cycle of the one branch at the first moment;

[0030] The duty cycle compensation amount obtained by the feedforward control is superimposed on the initial duty cycle of the one branch at the first moment to obtain the actual duty cycle of the one branch at the first moment.

[0031] Optionally, the duty cycle generating unit performs the following operations for another branch:

[0032] Performing voltage loop control on the voltage difference between the output voltage of the one branch at the second moment and the output voltage of the other branch at the second moment to obtain a duty cycle compensation amount of the other branch at the second moment;

[0033] The duty cycle compensation amount of the other branch at the second moment is superimposed on the actual duty cycle of the branch at the first moment to obtain the actual duty cycle of the other branch at the second moment.

[0034] Optionally, the duty cycle generating unit is used for:

[0035] The voltage and current of the one branch at the first moment are collected in real time by a current sensor arranged on the one branch of the multi-channel parallel converter.

[0036] Optionally, after collecting the voltage and current of a branch of the multi-channel parallel converter at the first moment, the current control device of the multi-channel parallel converter further includes a power limiting unit, and the power limiting unit is used to:

[0037] Obtaining a system current of the multi-channel parallel converter based on the phase current of the one branch at the third moment and the total number of branches of the multi-channel parallel converter;

[0038] Based on the system current of the multi-channel parallel converter and the output voltage of the one branch at the third moment, obtaining the output power of the multi-channel parallel converter;

[0039] When the output power is greater than the system set value, it is determined that the multi-channel parallel converter enters an abnormal operation state, and the operation mode of the multi-channel parallel converter is adjusted.

[0040] In a third aspect, an embodiment of the present application further provides an electronic device, comprising a processor and a memory, wherein the memory stores program code, and when the program code is executed by the processor, the processor executes the steps of any one of the above-mentioned current control methods for a multi-channel parallel converter.

[0041] In a fourth aspect, an embodiment of the present application further provides a computer-readable storage medium, which includes a program code. When the program product is run on an electronic device, the program code is used to enable the electronic device to execute the steps of any one of the above-mentioned current control methods for a multi-channel parallel converter.

[0042] In a fifth aspect, an embodiment of the present application further provides a computer program product, including computer instructions, which are executed by a processor to perform the steps of any of the above-mentioned current control methods for multi-channel parallel converters.

[0043] The beneficial effects of this application are as follows:

[0044] An embodiment of the present application provides a current control method, apparatus, device and storage medium for a multi-channel parallel converter, the method comprising: collecting the voltage and current of a branch of the multi-channel parallel converter at a first moment, and determining the actual duty cycle of the branch at the first moment based on the voltage and current of the branch at the first moment; then compensating for the actual duty cycle of the branch at the first moment to obtain the actual duty cycles of other branches in the multi-channel parallel converter at the second moment, and adjusting the phase current of the corresponding branch according to each actual duty cycle.

[0045] This application only deploys one current sensor to collect current values, realizes power limitation and overcurrent protection, reduces equipment production costs, reduces equipment size and weight, is conducive to the application of multi-channel parallel converters in low-cost application scenarios and small space application scenarios, and reduces the impact of factors such as production errors of multiple devices on control accuracy. This application also uses voltage parameters to control the phase current equalization of each branch in the multi-channel parallel converter, reduces the control loop, makes the controller design and control method relatively simple, and is more stable in actual operation, ensuring the stability and accuracy of the current equalization control precision.

[0046] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures specifically pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0048] Figure 1 A topological diagram of a multi-channel parallel DC converter for an emergency traction system provided in an embodiment of the present application;

[0049] Figure 2 A schematic diagram of an ideal current sharing waveform of each branch under ideal conditions provided in an embodiment of the present application;

[0050] Figure 3A A schematic diagram of a flow chart for controlling the phase current of each branch in a multi-channel parallel converter provided in an embodiment of the present application;

[0051] Figure 3B A logic diagram of controlling the phase current of each branch in a multi-channel parallel converter provided in an embodiment of the present application;

[0052] Figure 3C A schematic diagram of a flow chart of obtaining an actual duty cycle of another branch at a second moment provided in an embodiment of the present application;

[0053] Figure 4 A schematic structural diagram of a current control device for a multi-channel parallel converter provided in an embodiment of the present application;

[0054] Figure 5 A schematic diagram of a hardware structure of an electronic device to which an embodiment of the present application is applied;

[0055] Figure 6The present invention is a schematic diagram of the hardware structure of another electronic device to which the embodiments of the present application are applied. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the technical solution of the present application, rather than all of the embodiments. Based on the embodiments recorded in the application documents, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the technical solution of the present application.

[0057] The following is a brief introduction to the design concept of the embodiment of the present application:

[0058] Due to sudden factors such as overhead line failure, pantograph failure, natural disasters, etc., rail transit trains may be forced to stop due to external power supply interruption and unable to be traction. In this case, batteries are generally used for emergency traction. Due to the low voltage characteristics of the battery itself and the high power, harsh working environment and complex working conditions of rail transit vehicles, the voltage level of the battery needs to be increased by a DCDC converter before being output to the traction system of the rail transit vehicle.

[0059] Figure 1 The topology diagram of the multi-way parallel DC converter for emergency traction system. The converter adopts a nine-way staggered parallel structure. Each branch includes a switch tube Q and an inductor L. The converter circuit also includes a load R and an output capacitor C for stabilizing the output voltage. The switching frequency of the multi-way parallel converter is 2.5k, and the carrier phase shift of each branch is 40°. The function is to increase the input voltage of the battery from 90-130 volts (V) to 500V to meet the working requirements of rail transit vehicles.

[0060] In order to reduce the current stress of the device, a multi-way parallel design is generally used in the converter to achieve multi-way equalization of the output power. However, when the branches in the converter are connected in parallel, their characteristics and parameters will be affected by the production process and system errors. In actual operation, they will also be affected by load changes, manufacturing errors or some accidental control errors, resulting in phase current imbalance in one or several branches of the converter, resulting in large differences in the pressure of each branch, which may damage the device and converter.

[0061] To address the problem of unbalanced phase current in each branch of a multi-parallel converter, the traditional method is to set a current sensor in each branch to monitor the current of each branch in real time, and use a voltage and current dual closed-loop control algorithm to ensure current sharing in multiple parallel branches.

[0062] Commonly used methods include drooping current balancing method, master-slave current balancing method and average current balancing method. The drooping current balancing method is to achieve current balancing of each branch by changing the slope of the external characteristics of each phase and adjusting the output impedance. The master-slave current balancing method is to control the active phase current by the voltage outer loop, and the voltage outer loop and the current balancing loop jointly control the other phase currents, thereby achieving current balancing of each branch. The average current balancing method is to divide the output control quantity of the voltage outer loop into the given value of the inner loop of each phase current, and then realize the current balancing control through the proportional-integral (PI) controller. However, the above method requires the deployment of multiple current sensors to collect the current values ​​of each phase, which increases the production cost and volume of the equipment, and is difficult to be applied in low-cost application scenarios and small space application scenarios. In addition, the accuracy of the current balancing control is affected by the accuracy of the current sensor, and the stability and accuracy of the current balancing control accuracy cannot be guaranteed.

[0063] In order to solve the problems of low precision, poor stability, high cost and large size in current sharing control of multi-channel parallel converters, the present application proposes a current control method for multi-channel parallel converters. The method includes: collecting the voltage and current of a branch of the multi-channel parallel converter at the first moment, and determining the actual duty cycle of the branch at the first moment based on the voltage and current of the branch at the first moment; then compensating the actual duty cycle of the branch at the first moment to obtain the actual duty cycle of each other branch in the multi-channel parallel converter at the second moment, and adjusting the phase current of the corresponding branch according to each actual duty cycle.

[0064] This application only deploys one current sensor to collect current values, realizes power limitation and overcurrent protection, reduces equipment production costs, reduces equipment size and weight, is conducive to the application of multi-channel parallel converters in low-cost application scenarios and small space application scenarios, and reduces the impact of factors such as production errors of multiple devices on control accuracy. This application also uses voltage parameters to control the phase current equalization of each branch in the multi-channel parallel converter, reduces the control loop, makes the controller design and control method relatively simple, and is more stable in actual operation, ensuring the stability and accuracy of the current equalization control precision.

[0065] The preferred embodiments of the present application are described below in conjunction with the drawings in the specification. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In addition, the embodiments and features in the embodiments of the present application may be combined with each other if there is no conflict.

[0066] Figure 2 The figure shows the ideal current waveform diagram of each branch under ideal conditions. Figure 2It can be seen that when ideal current sharing is achieved in each branch, the peak and valley values of the voltage ripple at different moments in each time interval remain the same, and the moment when the voltage ripple peak occurs corresponds to the moment when the current valley occurs, and the moment when the voltage ripple valley occurs corresponds to the moment when the current peak occurs. Therefore, the following conclusion can be drawn: the ripple of the output voltage is related to the capacitor current and also has a certain pattern.

[0067] Table 1 shows the modal changes within one switching period when the multi-parallel converter circuit is operating. Among them, the row represents the switch tube number, the column represents the modal groups formed by each switch tube, n is the total number of switch tubes, where 1 represents on and 0 represents off. According to the condition of the number of simultaneously conducting switch tubes, the duty cycle operating range of this converter can be divided into nine intervals. When the duty cycle is in the interval of (n - 1) / 9 < d < n / 9, the multi-parallel converter turns on at most n switch tubes and at least n - 1 switch tubes. Therefore, there are 18 modes within one switching period.

[0068] Table 1

[0069]

[0070] By analyzing the circuit of the multi-parallel converter, the capacitor current expressions under different duty cycles as shown in Table 2 can be obtained.

[0071] Table 2

[0072]

[0073] It can be obtained from Table 2 that under different duty cycles, the modal duration and the capacitor current respectively have a certain pattern. Since the voltage ripple △V is equal to the capacitor charge Q divided by the capacitance value C (as shown in Equation 1), and the capacitor charge is related to the capacitor current i C (t) (as shown in Equation 2), that is, the capacitor current i C (t) can represent the current voltage ripple situation of the current capacitor. Assuming that the parameters of each phase of the multi-parallel converter are the same and the parasitic resistance of the Insulate-Gate Bipolar Transistor (IGBT) is ignored, then, when the nth switch tube of the converter is turned off, its inductor current expression is as shown in Equation 3, and from this, the peak and valley values of the voltage ripple are equal to the accumulation of the voltage ripple in a single mode (as shown in Equation 4). Among them, τ represents the turn-off time of the switch tube, i′ k represents the peak value of the inductor current of the kth branch, i k (t) represents the voltage ripple of the kth branch, i C (t) represents the peak and valley values of the output voltage ripple.

[0074]

[0075] Q = ∫i C (t)dt Formula 2;

[0076]

[0077] i C (t)=∑i k (t)-i 0 Formula 4;

[0078] By arranging the above multiple expressions, the core expression of voltage ripple can be derived (such as formula 5). 2k-1 Indicates the mode corresponding to the odd number, △V 2k Indicates the mode corresponding to the even number, k represents an integer sequence from 1 to 9, D represents the duty cycle, C represents the capacitance value, and L represents the inductance value; It means the result of rounding down 9 times the duty cycle value mathematically. Indicates the result of rounding up the duty cycle value by 9 times in mathematics; T s Indicates the time period; i (kmod9+m) represents the peak value of the inductor current (kmod9+m), where k is the same as the previous text, representing an integer sequence ranging from 1 to 9, m represents the number of switches turned off at this time (this number starts from 1), and mod is the remainder operator; V o represents the output voltage, R represents the load size, Represents the output current, V in represents input voltage, and t represents time.

[0079]

[0080] At the same time, the capacitor voltage in the time domain is related to the integral value of the current (as shown in Formula 6). Where C represents the capacitance value, i C (t) represents the peak-to-valley value of the output voltage ripple, V c Represents the voltage value of the capacitor, V n Indicates the output voltage ripple value after the nth mode, △V n Indicates the output voltage ripple value in the nth mode, Indicates the accumulated voltage ripple value after the first (n-1) modes.

[0081]

[0082] By rearranging Formula 5 and Formula 6, we can derive the expression of voltage in the time domain (such as Formula 7).

[0083]

[0084]

[0085] Formula 5 and Formula 7 are mainly related to the duty cycle, input and output voltage, load size, inductor and capacitor values, and switching cycle, indicating that there is a clear quantitative relationship between the duty cycle of each branch at a certain moment and the voltage at the same moment. This quantitative relationship is universal and applicable to multi-way parallel converters with n branches (n≥1). Therefore, under the premise of knowing this relationship, the duty cycle of a branch in the converter at this time can be derived from the output voltage value of the branch at this time.

[0086] Based on the above ideas, a current control method for a multi-channel parallel converter in an embodiment of the present application is proposed. Figure 3A-3B The schematic diagram shown specifically introduces the process of branch current control for multi-channel parallel converters.

[0087] S301: collecting voltage and current of a branch of a multi-parallel converter at a first moment, and determining an actual duty cycle of the branch at the first moment based on the voltage and current of the branch at the first moment.

[0088] like Figure 3B As shown, the voltage-current dual closed-loop control algorithm is used to calculate the initial duty cycle of a branch at the first moment, and then the duty cycle compensation amount of the branch is calculated using the feedforward algorithm. By superimposing the initial duty cycle of the branch and the duty cycle compensation amount, the actual duty cycle of the branch at the first moment is obtained.

[0089] Firstly, a current sensor arranged on a branch of the multi-channel parallel converter collects the output voltage and phase current of the branch at the first moment in real time.

[0090] Secondly, the voltage loop control is performed on the voltage difference between the voltage command and the output voltage of the branch at the first moment to generate the current command; the current loop control is performed on the current difference between the current command and the phase current of a branch at the first moment to generate the initial duty cycle of the branch at the first moment.

[0091] Voltage command V ref With the output voltage V o The voltage loop proportional-average-differential (Proportion Integration Differentiation, PID) controller generates a current command. The current command is then compared with the phase current I L5 The difference is made, and the current loop PID controller generates an initial duty cycle of the branch at the first moment.

[0092] In dual closed-loop control, the accuracy of the inner loop current command depends on the regulation of the outer loop voltage difference. In order to accurately track the voltage command and further enhance the load current resistance of the dual-loop control, the voltage outer loop can also use a PI controller, and the current inner loop uses a PI controller instead of a P controller. Furthermore, in order to take into account both the steady-state performance and dynamic performance of the system, the pole configuration method can be used to design the parameters of the PID controller. The pole configuration method is a control system design method for poles. The central idea is to configure the poles of the closed-loop system to a predetermined position so that it meets the requirements of stability and control performance.

[0093] Thirdly, the influence of input voltage and phase current on the system is introduced through the feedforward module. Different load adjustment methods are used to generate branch duty cycle compensation for the system's continuous inductance mode and discontinuous inductance mode to accelerate the dynamic response of the system. Specifically, based on the real-time acquisition of the input voltage V of a branch at the first moment, in , output voltage V o , Phase current I L5 The duty cycle compensation amount of a branch at the first moment is obtained by performing feedforward control. Finally, the duty cycle compensation amount obtained by the feedforward control is superimposed on the initial duty cycle of a branch at the first moment to obtain the actual duty cycle of the branch at the first moment.

[0094] S302: obtaining actual duty cycles of other branches in the multi-channel parallel converter at a second moment by compensating for an actual duty cycle of a branch at a first moment, and adjusting phase currents of corresponding branches according to the actual duty cycles.

[0095] Specifically, Figure 3C As shown, taking another branch as an example, the process of obtaining the actual duty cycle of the branch at the second moment is introduced.

[0096] S3021: performing voltage loop control on a voltage difference between an output voltage of one branch at the second moment and an output voltage of another branch at the second moment, to obtain a duty cycle compensation amount of another branch at the second moment;

[0097] S3022: superimpose the duty cycle compensation amount of another branch at the second moment with the actual duty cycle of a branch at the first moment to obtain an actual duty cycle of the other branch at the second moment.

[0098] The actual duty cycle of each branch is sent to the pulse controller of the corresponding branch, and the pulse controller adjusts the phase current flowing through the branch according to the actual duty cycle of the branch.

[0099] The method provided in the embodiment of the present application is used for current control, so that the phase currents of each branch in the multi-channel parallel converter after adjustment are the same. Therefore, the phase current collected by the current sensor can be regarded as the current value of each branch in the converter. Further, based on the phase current of a branch at the third moment and the total number of branches of the multi-channel parallel converter, the system current of the multi-channel parallel converter is obtained; and then based on the system current of the multi-channel parallel converter and the output voltage of a branch at the third moment, the output power of the multi-channel parallel converter is obtained. When the output power is greater than the system setting value, it is determined that the multi-channel parallel converter enters an abnormal operating state of overcurrent or overpower, and the operating mode of the multi-channel parallel converter is adjusted (such as switching the operating mode or shutting down), to ensure that the system has a certain dynamic current sharing capability and power limiting function, improve the stability and safety of equipment operation, and avoid device damage or equipment damage.

[0100] Figure 3B This is a topological diagram of a nine-way parallel converter. A current sensor is set on the fifth branch to collect the voltage and current of the fifth branch. The voltage and current dual closed-loop control algorithm and feedforward algorithm are then used to calculate the actual duty cycle of the fifth branch.

[0101] The actual duty cycle of the fifth channel is used as the reference duty cycle, and the output voltage of the fifth channel is used as the reference voltage. The output voltage of the nth channel and the reference voltage of the fifth channel are subjected to PI control to obtain the duty cycle compensation amount applied to the nth channel, and the duty cycle compensation amount is superimposed on the reference duty cycle to obtain the actual duty cycle of the nth channel.

[0102] The above process is implemented on other branches except those equipped with current sensors to obtain the actual duty cycle of each other branch, and realize the current sharing of multiple branches of the multi-way parallel converter. Compared with the traditional method of setting a current sensor on each branch, the single current sensor current sharing control strategy based on voltage ripple collection in this application has the advantages of simple equipment structure, easy control method, good control performance, good current sharing effect, and stable operation. It can realize high-performance control under a single current sensor, has low requirements on devices, and can also improve equipment reliability, realize stable power output, thereby reducing system losses and improving system efficiency.

[0103] Based on the same inventive concept as the above method embodiment, the present application embodiment also provides a current control device for a multi-channel parallel converter. Figure 4 As shown, the current control device 400 of the multi-channel parallel converter may include:

[0104] A duty cycle generating unit 401 is used to collect the voltage and current of a branch of the multi-channel parallel converter at a first moment, and determine the actual duty cycle of the branch at the first moment based on the voltage and current of the branch at the first moment;

[0105] By compensating the actual duty cycle of the one branch at the first moment, the actual duty cycle of each other branch in the multi-channel parallel converter at the second moment is obtained;

[0106] The current sharing adjustment unit 402 is used to adjust the phase current of the corresponding branch according to each actual duty cycle.

[0107] Optionally, the duty cycle generating unit 401 is used to:

[0108] Performing voltage loop control on a voltage difference between a voltage command and an output voltage of the one branch at a first moment to generate a current command;

[0109] Performing current loop control on a current difference between a current command and a phase current of the one branch at a first moment to generate an initial duty cycle of the one branch at the first moment;

[0110] The duty cycle compensation amount obtained by the feedforward control is superimposed on the initial duty cycle of the one branch at the first moment to obtain the actual duty cycle of the one branch at the first moment.

[0111] Optionally, the duty cycle generating unit 401 performs the following operations for another branch:

[0112] Performing voltage loop control on the voltage difference between the output voltage of the one branch at the second moment and the output voltage of the other branch at the second moment to obtain a duty cycle compensation amount of the other branch at the second moment;

[0113] The duty cycle compensation amount of the other branch at the second moment is superimposed on the actual duty cycle of the branch at the first moment to obtain the actual duty cycle of the other branch at the second moment.

[0114] Optionally, the duty cycle generating unit 401 is used to:

[0115] The voltage and current of the one branch at the first moment are collected in real time by a current sensor arranged on the one branch of the multi-channel parallel converter.

[0116] Optionally, after collecting the voltage and current of a branch of the multi-channel parallel converter at the first moment, the current control device 400 of the multi-channel parallel converter further includes a power limiting unit 403, and the power limiting unit 403 is used to:

[0117] Obtaining a system current of the multi-channel parallel converter based on the phase current of the one branch at the third moment and the total number of branches of the multi-channel parallel converter;

[0118] Based on the system current of the multi-channel parallel converter and the output voltage of the one branch at the third moment, obtaining the output power of the multi-channel parallel converter;

[0119] When the output power is greater than the system set value, it is determined that the multi-channel parallel converter enters an abnormal operation state, and the operation mode of the multi-channel parallel converter is adjusted.

[0120] For the convenience of description, the above parts are divided into modules (or units) according to their functions and described separately. Of course, when implementing this application, the functions of each module (or unit) can be implemented in the same or multiple software or hardware.

[0121] After introducing the current control method and device of the multi-channel parallel converter according to the exemplary embodiment of the present application, next, a multi-channel parallel converter according to another exemplary embodiment of the present application is introduced.

[0122] Those skilled in the art will appreciate that various aspects of the present application may be implemented as a system, method or program product. Therefore, various aspects of the present application may be specifically implemented in the following forms, namely: a complete hardware implementation, a complete software implementation (including firmware, microcode, etc.), or a combination of hardware and software, which may be collectively referred to as "circuit", "module" or "system" herein.

[0123] Based on the same inventive concept as the above method embodiment, an electronic device is also provided in the embodiment of the present application. In one embodiment, the electronic device may be a server. In this embodiment, the structure of the electronic device 500 is as follows: Figure 5 As shown, it may include at least a memory 501 , a communication module 503 , and at least one processor 502 .

[0124] The memory 501 is used to store computer programs executed by the processor 502. The memory 501 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system and programs required for running the instant messaging function, etc.; the data storage area may store various instant messaging information and operation instruction sets, etc.

[0125] The memory 501 may be a volatile memory, such as a random-access memory (RAM); the memory 501 may also be a non-volatile memory, such as a read-only memory, a flash memory, a hard disk drive (HDD) or a solid-state drive (SSD); or the memory 501 may be any other medium that can be used to carry or store a desired computer program in the form of instructions or data structures and can be accessed by a computer, but is not limited thereto. The memory 501 may be a combination of the above memories.

[0126] The processor 502 may include one or more central processing units (CPU) or a digital processing unit, etc. The processor 502 is used to implement the above-mentioned code stream fusion method when calling the computer program stored in the memory 501 .

[0127] The communication module 503 is used to communicate with terminal devices and other servers.

[0128] The specific connection medium between the memory 501, the communication module 503 and the processor 502 is not limited in the embodiment of the present application. Figure 5 In the embodiment, the memory 501 and the processor 502 are connected via a bus 504. The bus 504 is connected to the processor 502 via a bus 504. Figure 5 The connections between the other components are described with bold lines, which are only for illustrative purposes and are not intended to be limiting. The bus 504 can be divided into an address bus, a data bus, a control bus, etc. For ease of description, Figure 5 The diagram shows that only one thick line is used, but this does not mean that there is only one bus or only one type of bus.

[0129] The memory 501 stores a computer storage medium, and the computer storage medium stores computer executable instructions, and the computer executable instructions are used to implement the current control method of the multi-channel parallel converter in the embodiment of the present application. The processor 502 is used to execute the current control method of the multi-channel parallel converter, such as Figure 3A shown.

[0130] In another embodiment, the electronic device may also be other terminal devices. In this embodiment, the structure of the electronic device may be as follows: Figure 6 As shown, it includes: a communication component 610, a memory 620, a display unit 630, a camera 640, a sensor 650, an audio circuit 660, a Bluetooth module 670, a processor 680 and other components.

[0131] The communication component 610 is used to communicate with the server. In some embodiments, a wireless fidelity (WiFi) module may be included. The WiFi module belongs to a short-range wireless transmission technology. The electronic device can help the object to send and receive information through the WiFi module.

[0132] The memory 620 can be used to store software programs and data. The processor 680 executes various functions and data processing of the terminal device by running the software programs or data stored in the memory 620. The memory 620 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other volatile solid-state storage device. The memory 620 stores an operating system that enables the terminal device to run. In the present application, the memory 620 can store an operating system and various application programs, and can also store a computer program for executing the code stream fusion method of the embodiment of the present application.

[0133] The display unit 630 can also be used to display information input by the object or information provided to the object and a graphical user interface (GUI) of various menus of the terminal device. Specifically, the display unit 630 may include a display screen 632 arranged on the front of the terminal device. Among them, the display screen 632 can be configured in the form of a liquid crystal display, a light-emitting diode, etc. The display unit 630 can be used to display the code stream access selection interface, the panoramic video display interface, etc. in the embodiment of the present application.

[0134] The display unit 630 can also be used to receive input digital or character information and generate signal input related to the object setting and function control of the terminal device. Specifically, the display unit 630 may include a touch screen 631 arranged on the front of the terminal device, which can collect touch operations of objects on or near it, such as clicking a button, dragging a scroll box, etc.

[0135] The touch screen 631 can be covered on the display screen 632, or the touch screen 631 and the display screen 632 can be integrated to realize the input and output functions of the terminal device, and the integrated display screen can be referred to as a touch display screen. In this application, the display unit 630 can display the application and the corresponding operation steps.

[0136] Camera 640 can be used to capture static images, and the subject can publish the image taken by camera 660 through the application. Camera 660 can be one or more. The object generates an optical image through the lens and projects it onto the photosensitive element. The photosensitive element can be a charge coupled device (CCD) or a complementary metal-oxide-semiconductor (CMOS) phototransistor. The photosensitive element converts the optical signal into an electrical signal, and then passes the electrical signal to the processor 680 to convert it into a digital image signal.

[0137] The terminal device may further include at least one sensor 650, such as an acceleration sensor 651, a distance sensor 652, a fingerprint sensor 653, and a temperature sensor 654. The terminal device may also be configured with other sensors such as a gyroscope, a barometer, a hygrometer, a thermometer, an infrared sensor, a light sensor, and a motion sensor.

[0138] The audio circuit 660, the speaker 661, and the microphone 662 can provide an audio interface between the object and the terminal device. The audio circuit 660 can transmit the electrical signal converted from the received audio data to the speaker 661, which is converted into a sound signal for output. The terminal device can also be equipped with a volume button for adjusting the volume of the sound signal. On the other hand, the microphone 662 converts the collected sound signal into an electrical signal, which is received by the audio circuit 660 and converted into audio data, and then the audio data is output to the communication component 610 to be sent to, for example, another terminal device, or the audio data is output to the memory 620 for further processing.

[0139] The Bluetooth module 670 is used to exchange information with other Bluetooth devices having Bluetooth modules through the Bluetooth protocol. For example, the terminal device can establish a Bluetooth connection with a wearable electronic device (such as a smart watch) that also has a Bluetooth module through the Bluetooth module 670 to exchange data.

[0140] The processor 680 is the control center of the terminal device. It uses various interfaces and lines to connect various parts of the entire terminal. It executes various functions of the terminal device and processes data by running or executing software programs stored in the memory 620 and calling data stored in the memory 620. In some embodiments, the processor 680 may include one or more processing units; the processor 680 may also integrate an application processor and a baseband processor, wherein the application processor mainly processes the operating system, user interface, and application programs, and the baseband processor mainly processes wireless communications. It is understandable that the above-mentioned baseband processor may not be integrated into the processor 680. In the present application, the processor 680 can run the operating system, application programs, user interface display and touch response, as well as the current control method of the multi-channel parallel converter in the embodiment of the present application. In addition, the processor 680 is coupled to the display unit 630.

[0141] In some possible implementations, various aspects of the current control method for a multi-channel parallel converter provided in the present application may also be implemented in the form of a program product, which includes a computer program. When the program product is run on an electronic device, the computer program is used to enable the electronic device to execute the steps of the current control method for a multi-channel parallel converter according to various exemplary embodiments of the present application described above in this specification. For example, the electronic device may execute the following steps: Figure 3A Follow the steps shown in .

[0142] The program product may use any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. The readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of readable storage media (a non-exhaustive list) include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above.

[0143] The program product of the embodiment of the present application may adopt a portable compact disk read-only memory (CD-ROM) and include a computer program, and can be run on an electronic device. However, the program product of the present application is not limited thereto, and in this document, a readable storage medium may be any tangible medium containing or storing a program, which can be used by or in combination with a command execution system, apparatus, or device.

[0144] A readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, wherein a readable computer program is carried. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the foregoing. A readable signal medium may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with a command execution system, apparatus, or device.

[0145] The computer program embodied on the readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0146] The computer program for performing the operations of the present application may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, etc., and conventional procedural programming languages ​​such as "C" or similar programming languages. The computer program may be executed entirely on the user's computer device, partially on the user's computer device, as a separate software package, partially on the user's computer device and partially on a remote computer device, or entirely on the remote computer device. In the case of a remote computer device, the remote computer device may be connected to the user's computer device through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer device (e.g., via the Internet using an Internet service provider).

[0147] It should be noted that, although several units or subunits of the device are mentioned in the above detailed description, this division is merely exemplary and not mandatory. In fact, according to the embodiments of the present application, the features and functions of two or more units described above can be embodied in one unit. Conversely, the features and functions of one unit described above can be further divided into multiple units to be embodied.

[0148] In addition, although the operations of the method of the present application are described in a specific order in the drawings, this does not require or imply that the operations must be performed in this specific order, or that all the operations shown must be performed to achieve the desired results. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step, and / or one step may be decomposed into multiple steps.

[0149] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain a computer-usable computer program.

[0150] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program commands. These computer program commands can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the commands executed by the processor of the computer or other programmable data processing device generate commands for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0151] These computer program commands may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the commands stored in the computer readable memory produce an article of manufacture comprising a command device, the command device implementing the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0152] These computer program commands can also be loaded onto a computer or other programmable data processing device so that a series of operation steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the commands executed on the computer or other programmable device provide the instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0153] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0154] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A current control method for a multi-channel parallel converter, characterized in that: include: Collecting a voltage and current of a branch of the multi-channel parallel converter at a first moment, and determining an actual duty cycle of the branch at the first moment based on the voltage and current of the branch at the first moment; By compensating the actual duty cycle of the one branch at the first moment, the actual duty cycles of the other branches in the multi-channel parallel converter at the second moment are obtained, and the phase currents of the corresponding branches are adjusted according to the actual duty cycles.

2. The method according to claim 1, characterized in that The determining, based on the voltage and current of the branch at the first moment, an actual duty cycle of the branch at the first moment comprises: Performing voltage loop control on a voltage difference between a voltage command and an output voltage of the one branch at a first moment to generate a current command; Performing current loop control on a current difference between a current command and a phase current of the one branch at a first moment to generate an initial duty cycle of the one branch at the first moment; The duty cycle compensation amount obtained by the feedforward control is superimposed on the initial duty cycle of the one branch at the first moment to obtain the actual duty cycle of the one branch at the first moment.

3. The method according to claim 1, characterized in that By compensating the actual duty cycle of the one branch at the first moment, the actual duty cycle of each other branch in the multi-channel parallel converter at the second moment is obtained, wherein the following operations are performed for one other branch: Performing voltage loop control on the voltage difference between the output voltage of the one branch at the second moment and the output voltage of the other branch at the second moment to obtain a duty cycle compensation amount of the other branch at the second moment; The duty cycle compensation amount of the other branch at the second moment is superimposed on the actual duty cycle of the branch at the first moment to obtain the actual duty cycle of the other branch at the second moment.

4. The method according to claim 1, characterized in that The collecting of the voltage and current of a branch of the multi-channel parallel converter at the first moment includes: The voltage and current of the one branch at the first moment are collected in real time by a current sensor arranged on the one branch of the multi-channel parallel converter.

5. The method according to any one of claims 1 to 4, characterized in that: After collecting the voltage and current of a branch of the multi-channel parallel converter at the first moment, the method further includes: Obtaining a system current of the multi-channel parallel converter based on the phase current of the one branch at the third moment and the total number of branches of the multi-channel parallel converter; Based on the system current of the multi-channel parallel converter and the output voltage of the one branch at the third moment, obtaining the output power of the multi-channel parallel converter; When the output power is greater than the system set value, it is determined that the multi-channel parallel converter enters an abnormal operation state, and the operation mode of the multi-channel parallel converter is adjusted.

6. A current control device for a multi-channel parallel converter, characterized in that: include: A duty cycle generating unit, used for collecting the voltage and current of a branch of the multi-channel parallel converter at a first moment, and determining the actual duty cycle of the branch at the first moment based on the voltage and current of the branch at the first moment; By compensating the actual duty cycle of the one branch at the first moment, the actual duty cycle of each other branch in the multi-channel parallel converter at the second moment is obtained; The current sharing adjustment unit is used to adjust the phase current of the corresponding branch according to each actual duty cycle.

7. An electronic device, characterized in that: It comprises a processor and a memory, wherein the memory stores program codes, and when the program codes are executed by the processor, the processor executes the steps of the method according to any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that: The method comprises a program code, and when the program code is run on an electronic device, the program code is used to enable the electronic device to execute the steps of the method according to any one of claims 1 to 5.

9. A computer program product, characterized in that The method comprises computer instructions, which implement the steps of the method according to any one of claims 1 to 5 when executed by a processor.

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