Parallel inverter control method, device and equipment for suppressing ripple waves and medium

Abstract

The invention discloses a parallel inverter control method, device and equipment capable of suppressing ripple waves and a medium, and the method comprises the steps: obtaining a ripple wave signal after the output current of an inverter passes through a filtering inductor, and generating a dynamic step length signal according to the absolute value of the difference value between the ripple wave signal and a preset ripple wave allowable value; acquiring an output end voltage of the inverter, and generating a voltage regulation signal by adopting a model prediction controller according to a difference value between the output end voltage and a preset target voltage; and acquiring the output current of the inverter, generating a control signal of the inverter by adopting a model prediction controller according to the dynamic step length signal, the output current and the voltage regulation signal, and controlling the parallel inverter according to the control signal. According to the invention, the ripple suppression capability of the parallel inverter can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of inverter control technology, and in particular to a ripple-suppressing parallel inverter control method, device, equipment and medium. Background Art

[0002] In modern renewable energy power generation systems, industrial control and high power density applications, parallel inverters based on SiC MOSFET (silicon carbide field effect transistor) and Si IGBT (silicon insulated gate bipolar transistor) are widely used to improve power density, reduce losses and enhance the dynamic performance of the system. However, due to the differences in switching characteristics and conduction characteristics between SiC MOSFET and Si IGBT, the traditional control strategy has the problem of insufficient ripple suppression capability. It cannot adaptively adjust the ripple suppression strategy under different load conditions, which easily leads to high-frequency ripple and affects the output power quality. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a ripple-suppressing parallel inverter control method, device, equipment and medium, which can effectively improve the ripple suppression capability of the parallel inverter.

[0004] An embodiment of the present invention provides a parallel inverter control method for suppressing ripples, comprising: Acquire a ripple signal of the inverter output current after passing through the filter inductor, and generate a dynamic step signal according to the absolute value of the difference between the ripple signal and a preset ripple allowable value; Acquire the output terminal voltage of the inverter, and generate a voltage regulation signal using a model predictive controller according to the difference between the output terminal voltage and a preset target voltage; The output current of the inverter is obtained, and a control signal of the inverter is generated by using the model predictive controller according to the dynamic step signal, the output current and the voltage regulation signal, and the parallel inverter is controlled according to the control signal.

[0005] As an improvement of the above solution, generating a dynamic step signal according to the absolute value of the difference between the ripple signal and a preset ripple allowable value includes: According to the ripple signal and the preset ripple allowable value, the dynamic step signal is calculated by the following formula: in, is the dynamic step signal, and are the minimum and maximum step lengths respectively. is the adjustment function, Ripple signal Ripple allowable value The absolute value of the difference, , , , They are proportional adjustment parameter, integral adjustment parameter, differential adjustment parameter and acceleration adjustment parameter respectively. A constant to prevent the denominator from being zero.

[0006] As an improvement of the above scheme, the model predictive controller dynamically adjusts the reference current of the inverter so that the output current tracks the changes in load demand; the model predictive controller adjusts the working state of the inverter according to the dynamic step signal to reduce the error between the output voltage and the target voltage.

[0007] As an improvement of the above solution, the objective function J of the model predictive controller is: in, is the predicted voltage, k is an integer variable, To predict the time domain length, is the target voltage, is the reference current, is the output current of the inverter, and is the dynamic weight factor, and is the initial weight factor, is the load current deviation adjustment coefficient, is the ripple error adjustment coefficient, is a constant variable used to adjust the effect of step size on the dynamic performance of the system.

[0008] As an improvement of the above solution, the inverter includes a silicon carbide field effect transistor SiC MOSFET and a silicon insulated gate bipolar transistor Si IGBT connected in parallel; The model predictive controller adopts an optimized current distribution strategy; the current distribution strategy calculates a current distribution coefficient according to the equivalent on-resistance of the SiCMOSFET and the Si IGBT, and obtains reference currents corresponding to the SiC MOSFET and the Si IGBT according to the current distribution coefficient.

[0009] As an improvement of the above solution, the calculation formula of the current distribution coefficient is: in, and They are the current sharing coefficients of SiC MOSFET and Si IGBT respectively, and They are the equivalent on-resistance of SiC MOSFET and Si IGBT respectively.

[0010] As an improvement of the above solution, the predicted voltage is obtained based on the dynamic step signal using a preset state space model; The state space model is expressed as follows: in, is the predicted voltage at step k+1; matrix , By inductance ,resistance ,capacitance and step length Sure; is the switch state weight, is the switching state of the inverter; is the voltage error, ; , and They are proportional adjustment parameter, integral adjustment parameter and differential adjustment parameter respectively; , and They are the filter capacitance, filter inductance and equivalent on-resistance of SiC MOSFET respectively; , and They are the filter capacitance, filter inductance and equivalent on-resistance of Si IGBT respectively.

[0011] The embodiment of the present invention further provides a parallel inverter control device for suppressing ripples, comprising: A step adjustment module, used for obtaining a ripple signal of the inverter output current after passing through the filter inductor, and generating a dynamic step signal according to the absolute value of the difference between the ripple signal and a preset ripple allowable value; A voltage processing module, used for obtaining the output terminal voltage of the inverter, and generating a voltage regulation signal by using a model predictive controller according to the difference between the output terminal voltage and a preset target voltage; The inverter control module is used to obtain the output current of the inverter, generate the control signal of the inverter by using the model predictive controller according to the dynamic step signal, the output current and the voltage regulation signal, and control the parallel inverter according to the control signal.

[0012] An embodiment of the present invention further provides a computer device, comprising a processor and a memory, wherein a computer program is stored in the memory, and the computer program is configured to be executed by the processor, and when the processor executes the computer program, the parallel inverter control method for suppressing ripple as described in any one of the above items is implemented.

[0013] An embodiment of the present invention further provides a computer-readable storage medium, which stores a computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute any of the above-mentioned parallel inverter control methods for suppressing ripples.

[0014] Compared with the prior art, the beneficial effects of a ripple-suppressing parallel inverter control method, device, equipment and medium provided by an embodiment of the present invention are: by introducing a dynamic adjustment mechanism based on variable step size optimization, the ripple signal is collected in real time and compared with the set value, and then a dynamic step size signal is generated, so that the step size is adjusted in real time with the error, ripple and load state, which can effectively improve the dynamic response performance of the system, while ensuring the steady-state accuracy and reducing the calculation burden, and can effectively suppress the ripple under complex working conditions, thereby improving the dynamic performance and operation reliability of the inverter; by adopting a dynamic current distribution coefficient to optimize the current distribution of the parallel inverter, the current distribution of different devices can be balanced, the device overload can be prevented, and the system life can be improved; by linking the dynamic step size signal with the output current input controller, the reference current can be adaptively adjusted based on load demand, step size optimization, and ripple error feedback, ensuring that the output current accurately follows the load changes, improving the system's response speed and adjustment accuracy to dynamic load changes, and effectively improving the system's ripple suppression capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a flow chart of a parallel inverter control method for suppressing ripples provided by an embodiment of the present invention; Figure 2 1 is a schematic structural diagram of a SiC MOSFET / Si IGBT parallel inverter module provided in an embodiment of the present invention; Figure 3 is a structural schematic diagram of a parallel inverter control device for suppressing ripples provided by an embodiment of the present invention; Figure 4 It is a structural schematic diagram of a computer device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] See also Figure 1 , Figure 1 1 is a flow chart of a method for controlling a parallel inverter with ripple suppression provided by an embodiment of the present invention. The method for controlling a parallel inverter with ripple suppression includes: S1: obtaining a ripple signal of the inverter output current after passing through the filter inductor, and generating a dynamic step signal according to the absolute value of the difference between the ripple signal and a preset ripple allowable value; S2: obtaining an output terminal voltage of the inverter, and generating a voltage regulation signal using a model predictive controller according to a difference between the output terminal voltage and a preset target voltage; S3: Obtain the output current of the inverter, generate a control signal of the inverter using the model predictive controller according to the dynamic step signal, the output current and the voltage regulation signal, and control the parallel inverter according to the control signal.

[0018] Specifically, the embodiment of the present invention introduces a variable step size dynamic adjustment mechanism based on ripple signals for SiC MOSFET / Si IGBT parallel inverter modules, designs a dynamic cooperative control strategy for parallel modules, and proposes a ripple suppression algorithm based on model predictive control. Figure 2 As shown, the filter inductor at the inverter output collects and extracts the ripple signal , the ripple signal Ripple allowable value setting value After the difference, take the absolute value and get the absolute value error , input into the variable step length control module, in which the absolute value error and the ripple allowable error range are combined to generate a dynamic step length signal ; Collect the inverter output voltage , calculate the output voltage With standard voltage constant amplitude sine wave The difference between the output voltage and the target voltage is used as an error signal and input into the model predictive controller; the output current before filtering is extracted , the output current With dynamic step signal The input is into the model predictive controller, and the model predictive controller obtains the control signal of the inverter through calculation, thereby realizing ripple suppression. The embodiment of the present invention can effectively reduce the impact of ripple on the system under complex working conditions, improve the dynamic performance and operation reliability of the inverter, and is suitable for new energy power generation, high power density industrial control and dynamic load application scenarios.

[0019] As one of the optional embodiments, generating a dynamic step signal according to an absolute value of a difference between the ripple signal and a preset ripple allowable value includes: According to the ripple signal and the preset ripple allowable value, the dynamic step signal is calculated by the following formula: in, is the dynamic step signal, and are the minimum and maximum step lengths respectively. is the adjustment function, Ripple signal Ripple allowable value The absolute value of the difference, , , , They are proportional adjustment parameter, integral adjustment parameter, differential adjustment parameter and acceleration adjustment parameter respectively. A constant to prevent the denominator from being zero.

[0020] Specifically, variable step size optimization control ensures dynamic step size signal by limiting the step size range in real time. At minimum step length With maximum step length range to avoid system instability due to too large or too small step size.

[0021] Proportional adjustment parameters , can be based on the ripple error (i.e. The larger the ripple error, the stronger the regulation effect, which quickly generates a larger dynamic step signal, allowing the system to quickly respond to ripple changes and quickly suppress ripples.

[0022] Integral adjustment parameters , which is used to eliminate the steady-state error of the system. In the process of ripple suppression, when the ripple error is small and cannot be completely eliminated by proportional regulation, integral regulation accumulates the error and continuously adjusts the step size until the error is zero, so as to make the system output more stable and further improve the power quality.

[0023] Derivative adjustment parameters , used to adjust the step size according to the error change rate. When the ripple changes drastically, It can predict the error change trend in advance, adjust the step size in advance, suppress ripple growth in advance, and enhance system stability and anti-interference ability.

[0024] Acceleration adjustment parameters By introducing the acceleration factor, the step size adjustment is made more flexible. When the load changes suddenly and the ripple changes sharply, The step size adjustment can be accelerated to enable the system to quickly adapt to changes; when the ripple is close to the allowable value, It can slow down the change of step length, make the system smoothly enter a stable state, and avoid over-adjustment.

[0025] The step size in the prior art is often fixed or calculated based on simple rules, which is difficult to adapt to complex and changeable working conditions. The embodiment of the present invention uses a variable step size dynamic adjustment mechanism based on the ripple signal. When the ripple is large, the step size can be quickly increased to speed up the adjustment speed and quickly suppress the ripple; when the ripple is small, the step size can be reduced to improve the adjustment accuracy and avoid over-adjustment. By dynamically adjusting the step size according to the actual ripple situation, it is helpful to better adapt to the ripple changes under different working conditions, improve the adaptability of the system to complex working conditions, and better suppress ripples.

[0026] As one of the optional embodiments, the model predictive controller dynamically adjusts the reference current of the inverter so that the output current tracks the changes in load demand; the model predictive controller adjusts the working state of the inverter according to the dynamic step signal to reduce the error between the output voltage and the target voltage.

[0027] As one of the optional embodiments, the objective function J of the model predictive controller is: in, is the predicted voltage, k is an integer variable, To predict the time domain length, is the target voltage, is the reference current, is the output current of the inverter, and is the dynamic weight factor, and is the initial weight factor, is the load current deviation adjustment coefficient, is the ripple error adjustment coefficient, is a constant variable used to adjust the effect of step size on the dynamic performance of the system, and can make a trade-off between dynamic response and current fluctuation.

[0028] The weight can be adjusted dynamically according to the voltage error. When the error is large, the weight is increased to speed up the response, and when the error is small, the weight is reduced to reduce unnecessary adjustments. It can be adjusted in real time according to current error and load changes to adapt to different working conditions.

[0029] The predicted voltage and reference current are important variables in the objective function. The objective function achieves optimal control of the inverter by comprehensively predicting the voltage and reference current and adjusting them with dynamic weight factors. The predicted voltage is affected by the step signal. The change of the step signal will change the working state of the inverter (such as changing the on-off time of the power device of the inverter), causing the waveform of the output voltage to change, thereby affecting the predicted voltage. The model predictive controller adjusts the control strategy of the inverter to make the inverter output voltage as close to the ideal value as possible. The reference current is the current output value expected by the system. In the actual control process, the task of the model predictive controller is to make the actual output current of the inverter track the reference current, and minimize the deviation between the actual current and the reference current through optimization control, so as to meet the current demand of the load and ensure stable operation of the system.

[0030] As one of the optional embodiments, the predicted voltage is obtained based on the dynamic step signal using a preset state space model; The state space model is expressed as follows: in, is the predicted voltage at step k+1; matrix , By inductance ,resistance ,capacitance and step length Sure; is the switch state weight, is the switching state of the inverter; is the voltage error, ; , and They are proportional adjustment parameter, integral adjustment parameter and differential adjustment parameter respectively; , and They are the filter capacitance, filter inductance and equivalent on-resistance of SiC MOSFET respectively; , and They are the filter capacitance, filter inductance and equivalent on-resistance of Si IGBT respectively.

[0031] As one of the optional embodiments, the inverter includes a silicon carbide field effect transistor SiC MOSFET and a silicon insulated gate bipolar transistor Si IGBT connected in parallel; The model predictive controller adopts an optimized current distribution strategy; the current distribution strategy calculates a current distribution coefficient according to the equivalent on-resistance of the SiCMOSFET and the Si IGBT, and obtains reference currents corresponding to the SiC MOSFET and the Si IGBT according to the current distribution coefficient.

[0032] As one of the optional embodiments, the calculation formula of the current distribution coefficient is: in, and They are the current sharing coefficients of SiC MOSFET and Si IGBT respectively, and They are the equivalent on-resistance of SiC MOSFET and Si IGBT respectively.

[0033] Specifically, in view of the difference between SiC MOSFET inverter and Si IGBT inverter, the model predictive controller uses the designed current distribution optimization strategy to determine the current distribution coefficient according to the equivalent on-resistance of the inverter, and then calculates the reference current of SiC MOSFET and Si IGBT to achieve dynamic adjustment. In actual operation, the controller continuously adjusts the current distribution according to the real-time collected output current (as current feedback), thereby reducing current mismatch and thermal management pressure, and further improving the stability and reliability of system operation.

[0034] In a specific example, a distributed photovoltaic power generation system uses SiC MOSFET and Si IGBT parallel inverter modules with a rated power of 50kW.

[0035] First, the output voltage signal is collected by a high-precision sensor , target voltage , output current before filtering And the ripple signal after the filter inductor . Set the ripple allowable value is 5% of the rated current. At a certain moment, the 225V, 230V, For 100A, 3A. and The voltage error is calculated to be -5V and is input into the controller to generate a voltage regulation signal.

[0036] According to the ripple signal Ripple allowable value The absolute value error is calculated by comparing the results of is 2A, input the step length calculation module, set , , , , , the dynamic step length signal is calculated by the dynamic step length calculation formula It is 0.001s.

[0037] It is known that the equivalent on-resistance of SiC MOSFET is 0.05Ω, and the equivalent on-resistance of Si IGBT is 0.1Ω. The distribution coefficient of SiC MOSFET is calculated according to the current distribution coefficient formula: The distribution coefficient of Si IGBT is about 0.67. About 0.33. In the controller, combined with the total system reference current (determined to be 120A based on load demand and voltage control), and the reference current of the SiC MOSFET inverter is obtained , reference current of Si IGBT inverter Through precise current distribution, the current of SiC MOSFET and SiIGBT is reasonably distributed, and the current difference between the two is reduced by about 30% compared with the previous unoptimized state, reducing the thermal management pressure caused by current mismatch.

[0038] The dynamic step signal and output current signal Input model predictive controller, the parameters in the objective function J are set to , , , , , . The model predictive controller performs calculations based on these inputs and the objective function, and adjusts the control signal to make the inverter output voltage and current closer to the ideal value. By adopting the control method of the present invention, when the light intensity of the photovoltaic power generation system changes suddenly, resulting in a rapid change in load, the system can quickly adjust the output current within 8ms to meet the load demand, and the output current fluctuation range is controlled within ±3% of the rated current, which effectively improves the system's response speed and regulation accuracy to dynamic load changes, and ensures the stable operation and power quality of the photovoltaic power generation system.

[0039] The embodiment of the present invention introduces a dynamic adjustment mechanism based on variable step size optimization, collects ripple signals in real time and compares them with set values, and then generates a dynamic step size signal, so that the step size is adjusted in real time with the error, ripple, and load status, which can effectively improve the dynamic response performance of the system, while ensuring steady-state accuracy, reducing the calculation burden, and being able to effectively suppress ripple under complex working conditions, thereby improving the dynamic performance and operating reliability of the inverter; by adopting a dynamic current distribution coefficient to optimize the current distribution of parallel inverters, the current distribution of different devices can be balanced, device overload can be prevented, and the system life can be increased; by linking the dynamic step size signal with the output current input controller, the reference current can be adaptively adjusted based on load demand, step size optimization, and ripple error feedback, ensuring that the output current accurately follows the load changes, thereby improving the system's response speed and adjustment accuracy to dynamic load changes, and effectively improving the system's ripple suppression capability.

[0040] Correspondingly, the present invention also provides a ripple-suppressing parallel inverter control device, which can implement all the processes of the ripple-suppressing parallel inverter control method in the above embodiment.

[0041] See also Figure 3 , Figure 3 1 is a schematic diagram of a parallel inverter control device for suppressing ripples provided by an embodiment of the present invention. The parallel inverter control device for suppressing ripples comprises: The step length adjustment module 301 is used to obtain a ripple signal of the inverter output current after passing through the filter inductor, and generate a dynamic step length signal according to the absolute value of the difference between the ripple signal and a preset ripple allowable value; The voltage processing module 302 is used to obtain the output voltage of the inverter, and generate a voltage regulation signal using a model predictive controller according to the difference between the output voltage and a preset target voltage; The inverter control module 303 is used to obtain the output current of the inverter, generate the control signal of the inverter using the model predictive controller according to the dynamic step signal, the output current and the voltage regulation signal, and control the parallel inverter according to the control signal.

[0042] Preferably, generating a dynamic step signal according to an absolute value of a difference between the ripple signal and a preset ripple allowable value comprises: According to the ripple signal and the preset ripple allowable value, the dynamic step signal is calculated by the following formula: in, is the dynamic step signal, and are the minimum and maximum step lengths respectively. is the adjustment function, Ripple signal Ripple allowable value The absolute value of the difference, , , , They are proportional adjustment parameter, integral adjustment parameter, differential adjustment parameter and acceleration adjustment parameter respectively. A constant to prevent the denominator from being zero.

[0043] Preferably, the model predictive controller dynamically adjusts the reference current of the inverter so that the output current tracks the change in load demand; the model predictive controller adjusts the working state of the inverter according to the dynamic step signal to reduce the error between the output terminal voltage and the target voltage.

[0044] Preferably, the objective function J of the model predictive controller is: in, is the predicted voltage, k is an integer variable, To predict the time domain length, is the target voltage, is the reference current, is the output current of the inverter, and is the dynamic weight factor, and is the initial weight factor, is the load current deviation adjustment coefficient, is the ripple error adjustment coefficient, is a constant variable used to adjust the effect of step size on the dynamic performance of the system.

[0045] Preferably, the inverter comprises a silicon carbide field effect transistor SiC MOSFET and a silicon insulated gate bipolar transistor Si IGBT connected in parallel; The model predictive controller adopts an optimized current distribution strategy; the current distribution strategy calculates a current distribution coefficient according to the equivalent on-resistance of the SiCMOSFET and the Si IGBT, and obtains reference currents corresponding to the SiC MOSFET and the Si IGBT according to the current distribution coefficient.

[0046] Preferably, the calculation formula of the current distribution coefficient is: in, and They are the current sharing coefficients of SiC MOSFET and Si IGBT respectively, and They are the equivalent on-resistance of SiC MOSFET and Si IGBT respectively.

[0047] Preferably, the predicted voltage is obtained based on the dynamic step signal using a preset state space model; The state space model is expressed as follows: in, is the predicted voltage at step k+1; matrix , By inductance ,resistance ,capacitance and step length Sure; is the switch state weight, is the switching state of the inverter; is the voltage error, ; , and They are proportional adjustment parameter, integral adjustment parameter and differential adjustment parameter respectively; , and They are the filter capacitance, filter inductance and equivalent on-resistance of SiC MOSFET respectively; , and They are the filter capacitance, filter inductance and equivalent on-resistance of Si IGBT respectively.

[0048] In specific implementation, the working principle, control process and technical effect achieved by the ripple suppression parallel inverter control device provided in the embodiment of the present invention are the same as those of the ripple suppression parallel inverter control method in the above embodiment, and will not be repeated here.

[0049] See also Figure 4 , Figure 4 4 is a block diagram of a computer device provided in an embodiment of the present invention, wherein the computer device includes: a processor 401, a memory 402, and a computer program stored in the memory 402 and executable on the processor 401. When the processor 401 executes the computer program, the steps in the above-mentioned ripple suppression parallel inverter control method embodiment are implemented. Alternatively, when the processor 401 executes the computer program, the functions of each module / unit in the above-mentioned device embodiments are implemented.

[0050] Exemplarily, the computer program may be divided into one or more modules / units, which are stored in the memory 402 and executed by the processor 401 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program in the computer device.

[0051] The computer device may include, but is not limited to, a processor 401 and a memory 402. Those skilled in the art will appreciate that the schematic diagram is merely an example of a computer device and does not constitute a limitation on the computer device, and may include more or fewer components than shown in the diagram, or may combine certain components, or different components, for example, the computer device may also include an input / output device, a network access device, a bus, etc.

[0052] The processor 401 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor 401 is the control center of the computer device, and uses various interfaces and lines to connect various parts of the entire computer device.

[0053] The memory 402 can be used to store the computer program and / or module. The processor 401 implements various functions of the computer device by running or executing the computer program and / or module stored in the memory 402 and calling the data stored in the memory 402. The memory 402 can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.); the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.). In addition, the memory 402 can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (SecureDigital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0054] Wherein, if the module / unit integrated in the computer device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor 401. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form, etc. The computer-readable medium can include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0055] An embodiment of the present invention further provides a computer-readable storage medium, which includes a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute the ripple-suppressing parallel inverter control method described in any of the above embodiments.

[0056] The embodiments of the present invention provide a ripple-suppressing parallel inverter control method, device, equipment and medium, which have the beneficial effects of: by introducing a dynamic adjustment mechanism based on variable step size optimization, the ripple signal is collected in real time and compared with the set value, and then a dynamic step size signal is generated, so that the step size is adjusted in real time with the error, ripple and load state, which can effectively improve the dynamic response performance of the system, while ensuring the steady-state accuracy, reducing the calculation burden, and being able to effectively suppress the ripple under complex working conditions, thereby improving the dynamic performance and operation reliability of the inverter; by adopting a dynamic current distribution coefficient to optimize the current distribution of the parallel inverter, the current distribution of different devices can be balanced, the device overload can be prevented, and the system life can be improved; by linking the dynamic step size signal with the output current input controller, the reference current can be adaptively adjusted based on the load demand, step size optimization, and ripple error feedback, ensuring that the output current accurately follows the load changes, improving the system's response speed and adjustment accuracy to dynamic load changes, and effectively improving the system's ripple suppression capability.

[0057] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A parallel inverter control method for suppressing ripple, characterized in that: include: Acquire a ripple signal of the inverter output current after passing through the filter inductor, and generate a dynamic step signal according to the absolute value of the difference between the ripple signal and a preset ripple allowable value; Acquire the output terminal voltage of the inverter, and generate a voltage regulation signal using a model predictive controller according to the difference between the output terminal voltage and a preset target voltage; The output current of the inverter is obtained, and a control signal of the inverter is generated by using the model predictive controller according to the dynamic step signal, the output current and the voltage regulation signal, and the parallel inverter is controlled according to the control signal.

2. The ripple suppression parallel inverter control method according to claim 1, characterized in that: The step of generating a dynamic step signal according to the absolute value of the difference between the ripple signal and a preset ripple allowable value comprises: According to the ripple signal and the preset ripple allowable value, the dynamic step signal is calculated by the following formula: in, is the dynamic step signal, and are the minimum and maximum step lengths respectively. is the adjustment function, Ripple signal Ripple allowable value The absolute value of the difference, , , , They are proportional adjustment parameter, integral adjustment parameter, differential adjustment parameter and acceleration adjustment parameter respectively. A constant to prevent the denominator from being zero.

3. The ripple suppression parallel inverter control method according to claim 1, characterized in that: The model predictive controller dynamically adjusts the reference current of the inverter so that the output current tracks the change of load demand; the model predictive controller adjusts the working state of the inverter according to the dynamic step signal to reduce the error between the output terminal voltage and the target voltage.

4. The ripple suppression parallel inverter control method according to claim 3, characterized in that: The objective function J of the model predictive controller is: in, is the predicted voltage, k is an integer variable, To predict the time domain length, is the target voltage, is the reference current, is the output current of the inverter, and is the dynamic weight factor, and is the initial weight factor, is the load current deviation adjustment coefficient, is the ripple error adjustment coefficient, is a constant variable used to adjust the effect of step size on the dynamic performance of the system.

5. The ripple suppression parallel inverter control method according to claim 4, characterized in that: The inverter comprises a silicon carbide field effect transistor SiC MOSFET and a silicon insulated gate bipolar transistor Si IGBT connected in parallel; The model predictive controller adopts an optimized current distribution strategy; the current distribution strategy calculates a current distribution coefficient according to the equivalent on-resistance of the SiCMOSFET and the Si IGBT, and obtains reference currents corresponding to the SiC MOSFET and the Si IGBT according to the current distribution coefficient.

6. The ripple suppression parallel inverter control method according to claim 5, characterized in that: The calculation formula of the current distribution coefficient is: in, and They are the current sharing coefficients of SiC MOSFET and Si IGBT respectively, and They are the equivalent on-resistance of SiC MOSFET and Si IGBT respectively.

7. The ripple suppression parallel inverter control method according to claim 4, characterized in that: The predicted voltage is obtained based on the dynamic step signal using a preset state space model; The state space model is expressed as follows: in, is the predicted voltage at step k+1; matrix , By inductance ,resistance ,capacitance and step length Sure; is the switch state weight, is the switching state of the inverter; is the voltage error, ; , and They are proportional adjustment parameter, integral adjustment parameter and differential adjustment parameter respectively; , and They are the filter capacitance, filter inductance and equivalent on-resistance of SiC MOSFET respectively; , and They are the filter capacitance, filter inductance and equivalent on-resistance of Si IGBT respectively.

8. A parallel inverter control device for suppressing ripple, characterized in that: include: A step adjustment module, used for obtaining a ripple signal of the inverter output current after passing through the filter inductor, and generating a dynamic step signal according to the absolute value of the difference between the ripple signal and a preset ripple allowable value; A voltage processing module, used for obtaining the output terminal voltage of the inverter, and generating a voltage regulation signal by using a model predictive controller according to the difference between the output terminal voltage and a preset target voltage; The inverter control module is used to obtain the output current of the inverter, generate the control signal of the inverter by using the model predictive controller according to the dynamic step signal, the output current and the voltage regulation signal, and control the parallel inverter according to the control signal.

9. A computer device, characterized in that: It comprises a processor and a memory, wherein a computer program is stored in the memory, and the computer program is configured to be executed by the processor, and when the processor executes the computer program, the parallel inverter control method for suppressing ripple as described in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, wherein when the device where the computer-readable storage medium is located executes the computer program, the parallel inverter control method for suppressing ripples as described in any one of claims 1 to 7 is implemented.

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