Distributed power distribution system control method and system

Abstract

The invention discloses a distributed power distribution system control method and system, and the method comprises the steps: collecting first output data of a distributed power distribution system, and calculating a first switching function; and if the value of the first switching function exceeds a first critical value when the system is started, tracking the maximum power point by adopting a perturbation and observation method so as to improve the dynamic response speed of the system, and when the system tracks near the maximum power point, switching the system into sliding mode control to realize tracking control of the distributed power generation maximum power point. The invention aims to enhance the robustness, the dynamic response speed and the steady-state precision of system operation, maintain the stability of the direct-current bus voltage, and further improve the overall operation stability of the system. The improved sliding mode control not only improves the stability and reliability of the grid-connected operation of the system, but also realizes the self-adaptive switching of the operation mode and reduces the response time by combining a perturbation and observation method, and can better track and control the output quantity and effectively suppress the fluctuation of the bus voltage, thereby reducing the steady-state error.

Description

Technical Field

[0001] The present invention relates to the technical field of power system control, and in particular to a distributed power distribution system control method and system. Background Art

[0002] In order to cope with many problems such as environmental pollution, climate change, and energy depletion crisis, the development and utilization of renewable energy and the transformation of energy structure have been significantly accelerated, making the traditional power system based on fossil energy and hydropower gradually transform into a distributed distribution system based on renewable energy such as solar energy and wind energy. Distributed distribution systems can operate in grid-connected mode and island mode.

[0003] However, the nonlinear loads in the actual operation of distributed power distribution systems, the uncertainty caused by the fluctuation of photovoltaic modules, and the parameter perturbations caused by multiple power electronic devices will seriously affect the stable operation of the system. The external loop voltage system, source output and DC direct current voltage regulation will bring uncertainty. Such non-matching uncertainty cannot be compensated by the system itself, resulting in output voltage fluctuations and steady-state errors. Moreover, when distributed power distribution systems operate in isolation, more and more sliding mode control is adopted. Although traditional sliding mode control has high robustness and strong reliability, it still lacks in response speed and steady-state accuracy.

[0004] After searching the existing technical literature, it was found that Li Mengshuai proposed an improved control algorithm based on sliding mode control in "Research on MPPT Algorithm and Control of Photovoltaic Power Generation", but this method only considered a single photovoltaic power generation unit and its application scope was too narrow. Summary of the invention

[0005] In view of the above existing problems, the present invention is proposed.

[0006] Therefore, the present invention provides a distributed power distribution system control method and system to solve the system stability problems caused by parameter perturbations caused by nonlinear loads, photovoltaic component fluctuations and multiple power electronic devices in the distributed power distribution system, especially the problems of insufficient response speed and steady-state accuracy of sliding mode control in island mode.

[0007] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0008] In a first aspect, the present invention provides a distributed power distribution system control method, comprising: collecting first output data of the distributed power distribution system, and calculating a first switching function; if the value of the first switching function exceeds a first critical value when the system starts, a perturbation observation method is used to track the maximum power point; otherwise, the system switches to sliding mode control to achieve tracking control of the maximum power point of distributed power generation.

[0009] As a preferred solution of the distributed power distribution system control method described in the present invention, the first switching function is a function derived based on the collected first output data of the distributed power distribution system, which is used to determine whether the system switches to disturbance observation control or sliding mode control.

[0010] As a preferred solution of the distributed power distribution system control method of the present invention, if the value of the first switching function exceeds the first critical value when the system starts, the maximum power point tracking is performed using the disturbance observation method, which includes:

[0011] Initializing relevant parameters of the disturbance observation method when the distributed power distribution system is started;

[0012] Applying a first disturbance step size at a current operating point and changing an input condition of the distributed power distribution system;

[0013] Calculate the current output power according to the collected first output data of the distributed power distribution system;

[0014] Comparing the output power after the disturbance with the output power before the disturbance to determine whether the current output power is higher than the previous output power;

[0015] If the output power after the disturbance increases, it is considered that the current disturbance direction is correct, and the working point continues to be adjusted in this direction. If the output power after the disturbance decreases, it is considered that the current disturbance direction is wrong, and the disturbance direction is changed and the working point is adjusted in the opposite direction.

[0016] The above-mentioned process of disturbance, calculation, comparison and update is repeated continuously to gradually approach the maximum power point.

[0017] As a preferred solution of the distributed power distribution system control method described in the present invention, the relevant parameters of the initialization disturbance observation method when the distributed power distribution system is started include the initial working point, the converter duty cycle, and the duty cycle disturbance step.

[0018] As a preferred solution of the distributed power distribution system control method described in the present invention, when the value of the first switching function is less than the first critical value, the system determines that it is close to the maximum power point. At this time, the disturbance observation method is stopped and switched to the sliding mode control mode to ensure steady-state accuracy.

[0019] As a preferred solution of the distributed power distribution system control method described in the present invention, the system switches to sliding mode control to achieve tracking control of the maximum power point of distributed power generation, including adjusting the converter duty cycle to ensure the best steady-state accuracy when the system tracks the maximum power point.

[0020] As a preferred solution of the distributed power distribution system control method of the present invention, wherein: adjusting the duty cycle of the converter includes:

[0021] When the value of the first switching function is less than the first critical value, the system switches to the sliding mode control mode and continues to determine whether the value of the first switching function is greater than 0;

[0022] If the value of the first switching function is greater than 0, the duty cycle of the converter is adjusted to D1 = D0 + k x If the value of the first switching function is less than or equal to 0, the duty cycle of the converter is adjusted to D1 = D0-k x , where D1 represents the duty cycle of the converter after adjustment, D0 represents the duty cycle of the converter before adjustment, k x represents the equivalent duty cycle disturbance step size of the sliding mode control mode;

[0023] After the converter duty cycle is adjusted, the output voltage U(k) and the output current I(k) are updated to the values ​​of the current cycle, and secondary feedback is performed to prepare for the next iteration.

[0024] In a second aspect, the present invention provides a distributed power distribution system control system, comprising:

[0025] A data acquisition and calculation module, used for acquiring first output data of the distributed power distribution system and calculating a first switching function;

[0026] A first tracking control module, configured to use a perturbation observation method to track the maximum power point if the value of the first switching function exceeds a first critical value when the system is started;

[0027] The second tracking control module is used to stop using the disturbance observation method and switch to the sliding mode control mode to achieve tracking control of the maximum power point of distributed generation when the value of the first switching function is less than the first critical value and the system determines that it is close to the maximum power point.

[0028] In a third aspect, the present invention provides a computing device, comprising:

[0029] Memory and processor;

[0030] The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the distributed power distribution system control method are implemented.

[0031] In a fourth aspect, the present invention provides a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, implement the steps of the distributed power distribution system control method.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention proposes a distributed power distribution system control method and system based on improved sliding mode control, aiming to enhance the robustness, dynamic response speed and steady-state accuracy of system operation, maintain the stability of the DC bus voltage, and thus improve the overall operation stability of the system; the improved sliding mode control of the present invention not only improves the stability and reliability of the system grid-connected operation, but also realizes adaptive switching of the operation mode by combining the disturbance observation method, reduces the response time, and can better track and control the output, effectively suppress the fluctuation of the bus voltage, thereby reducing the steady-state error. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0034] Figure 1 A schematic diagram of the overall process logic of a distributed power distribution system control method according to an embodiment of the present invention;

[0035] Figure 2 A schematic diagram of a distributed power distribution system of a distributed power distribution system control method according to an embodiment of the present invention;

[0036] Figure 3 A schematic diagram of a distributed power distribution system control strategy based on improved sliding mode control adopted by a distributed power distribution system control method according to an embodiment of the present invention;

[0037] Figure 4 This is a flow chart of an improved sliding mode control adopted by a distributed power distribution system control method according to an embodiment of the present invention;

[0038] Figure 5 A common bus voltage waveform diagram of a distributed power distribution system control method according to an embodiment of the present invention;

[0039] Figure 6 This is a waveform diagram of active power outputted by a distributed power distribution system control method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0041] Example 1

[0042] Reference Figure 1 , Figure 3 and Figure 4 As an embodiment of the present invention, a distributed power distribution system control method is provided to solve the problems of slow dynamic response speed and insufficient steady-state accuracy in the distributed power distribution network, which is applicable to the stable control of the operation of the distributed power distribution network in the scenario of applying the sliding mode control technology. Figure 1 The specific steps shown include:

[0043] S100: collecting first output data of the distributed power distribution system and calculating a first switching function;

[0044] S200: if the value of the first switching function exceeds the first critical value when the system is started, a perturbation observation method is used to track the maximum power point;

[0045] S300: When the value of the first switching function is less than the first critical value, the system determines that it is close to the maximum power point. At this time, the disturbance observation method is stopped and the sliding mode control mode is switched to realize the tracking control of the maximum power point of distributed generation.

[0046] It should be noted that the present invention proposes a distributed power distribution system control method and system based on improved sliding mode control, which aims to enhance the robustness, dynamic response speed and steady-state accuracy of system operation, maintain the stability of the DC bus voltage, and thus improve the overall operation stability of the system; the improved sliding mode control of the present invention not only improves the stability and reliability of the system's grid-connected operation, but also realizes adaptive switching of the operation mode by combining the disturbance observation method, reduces the response time, and can better track and control the output, effectively suppress the fluctuation of the bus voltage, thereby reducing the steady-state error.

[0047] In the embodiment of the present application, the above step S100 includes the following sub-steps A1-A2;

[0048] In A1: collecting first output data of the distributed power distribution system;

[0049] In A2: the output power is calculated according to the collected first output data of the distributed power distribution system, and then the first switching function is derived according to the output power;

[0050] In an optional embodiment, the first output data is the output voltage and output current of the distributed power distribution system. The output power is calculated by the output voltage and output current of the distributed power distribution system, and is further used to derive a first switching function to determine when to switch from one control mode to another.

[0051] In an optional implementation, the first switching function may be a function derived from the collected output voltage and output current of the distributed power distribution system, to determine whether the system switches to disturbance observation control or sliding mode control;

[0052] In another optional implementation, the first switching function may also be a function defined by the difference between the current system state and the maximum power point state predicted by the model; the first switching function may also be a function defined by the difference between the current operating point and the proportionality factor of the known maximum power point;

[0053] In the embodiment of the present application, the first switching function is a function derived from the collected output voltage and output current of the distributed power distribution system. It can be seen from the output characteristics of the distributed power distribution system that when the distributed power distribution system operates at the maximum power point:

[0054]

[0055] From the above formula, we can know that:

[0056]

[0057] Therefore, the selectable switching function is:

[0058]

[0059] It should be noted that step S100 can flexibly respond to changes in the system under different operating conditions, and calculate power in real time by accurately measuring voltage and current, thereby ensuring that the system can quickly and accurately identify and track the maximum power point. In addition, by defining the first switching function to distinguish the switching timing of the two control modes, not only the response speed and accuracy of the system when approaching the maximum power point are improved, but also the robustness of the entire system is enhanced, so that the system can maintain a stable and efficient operating state in the face of changes in the external environment, and finally achieve the optimal control of the maximum power point tracking of the distributed power generation system.

[0060] like Figure 3 FIG. 1 is a schematic diagram of a distributed power distribution system control strategy based on improved sliding mode control adopted in this embodiment. In the figure, U dc is the equivalent output DC voltage of the distributed power supply, L f is the line equivalent inductance, R f is the line equivalent grounding resistance, Cf is the line equivalent grounding capacitance, U and I are the collected inverter output voltage and output current respectively; the biggest difference between the control strategy provided in this embodiment and the traditional control strategy is: 1. The sliding mode control is introduced, and 2. The sliding mode control is optimized by using the disturbance observation method.

[0061] In the embodiment of the present application, the above step S200 includes the following sub-steps B1-B6: Figure 4 As shown;

[0062] In B1: Initialize the relevant parameters of the disturbance observation method when the distributed distribution system starts;

[0063] In B2: applying the first disturbance step at the current operating point and changing the input conditions of the distributed distribution system;

[0064] In B3: calculating the current output power according to the collected first output data of the distributed power distribution system;

[0065] In B4: comparing the output power after the disturbance with the output power before the disturbance to determine whether the current output power is higher than the previous output power;

[0066] In B5: if the output power after the disturbance increases, it is considered that the current disturbance direction is correct, and the working point continues to be adjusted in this direction; if the output power after the disturbance decreases, it is considered that the current disturbance direction is wrong, and the disturbance direction is changed, and the working point is adjusted in the opposite direction;

[0067] In B6: the above perturbation, calculation, comparison and update process is repeated continuously to gradually approach the maximum power point;

[0068] Specifically, the relevant parameters of the initialization disturbance observation method when the distributed power distribution system is started include the initial working point, the converter duty cycle, and the duty cycle disturbance step size.

[0069] In an optional implementation, the first perturbation step size refers to the step size used when the operating point is first perturbed when the system is started, and can be a preset value; the first perturbation step size determines the amplitude of the system's adjustment of the operating point in the process of searching for the maximum power point, and needs to be determined based on the following factors: ① Different distributed power distribution systems may have different response speeds and power curve characteristics, so it is necessary to select a suitable step size based on the characteristics and application scenarios of the specific system; ② If the system requires a faster search for the maximum power point, a larger step size can be selected to speed up the search; but if more attention is paid to accuracy, that is, better convergence is desired near the maximum power point, a smaller step size should be selected; ③ In the case of large changes in external conditions such as light intensity or temperature, a larger step size may be required to quickly track the maximum power point; and under relatively stable environmental conditions, a smaller step size can be used to improve the search accuracy;

[0070] Exemplarily, for MPPT applications in a photovoltaic system, the first perturbation step size may be a small percentage increment of voltage or current, such as 0.5% to 5% of the current operating point value.

[0071] In an optional implementation, the first critical value may be a power deviation, a voltage deviation or other indicator that can represent the distance between the system state and the maximum power point relative to the maximum power point. The first critical value is used to determine whether the system is close to a threshold of the maximum power point. When the value of the first switching function is lower than the critical value, the system will consider that it is close enough to the maximum power point, and thus switch to the sliding mode control mode.

[0072] For example, in a typical photovoltaic system, the first critical value may be set to a small percentage of the power change near the maximum power point, such as a power change of 1% to 5%, or a fixed value of the voltage change relative to the current operating point, such as a few millivolts to tens of millivolts.

[0073] It should be noted that, in step S200, by applying the first disturbance step size at the current working point and changing the input conditions, the system can calculate the current output power based on the collected first output data, and compare this power with the power before the disturbance, so as to determine whether the direction of the disturbance helps to improve the efficiency of the system. If the output power increases after the disturbance, the system believes that the current disturbance direction is correct, and continues to adjust the working point in this direction; conversely, if the power decreases, the system will change the disturbance direction and adjust the working point in the opposite direction. This process is repeated continuously, so that the system can dynamically adapt to environmental changes, and by gradually approaching the maximum power point, it ensures that the system is always in the optimal operating state, thereby improving the overall energy conversion efficiency and system stability.

[0074] In the embodiment of the present application, the above step S300 includes the following sub-step C1;

[0075] In C1: the system switches to sliding mode control to achieve tracking control of the maximum power point of distributed generation, including adjusting the converter duty cycle to ensure that the system has the best steady-state accuracy when tracking the maximum power point;

[0076] Specifically, Figure 4 As shown, adjusting the converter duty cycle includes:

[0077] When the value of the first switching function is less than the first critical value, the system switches to the sliding mode control mode and continues to determine whether the value of the first switching function is greater than 0;

[0078] If the value of the first switching function is greater than 0, the duty cycle of the converter is adjusted to D1 = D0 + k xIf the value of the first switching function is less than or equal to 0, the duty cycle of the converter is adjusted to D1 = D0-k x , where D1 represents the duty cycle of the converter after adjustment, D0 represents the duty cycle of the converter before adjustment, k x represents the equivalent duty cycle disturbance step size of the sliding mode control mode;

[0079] After the converter duty cycle is adjusted, the output voltage U(k) and the output current I(k) are updated to the values ​​of the current cycle, and secondary feedback is performed to prepare for the next iteration.

[0080] It should be noted that step S300 ensures that the system can efficiently approach the maximum power point and realize closed-loop feedback control by continuously updating the output voltage and current. The precise adjustment strategy not only improves the system's tracking accuracy of the maximum power point, but also enhances the system's robustness, enabling it to operate stably in various environments, thereby improving the overall efficiency and reliability of the distributed power generation system.

[0081] The above is a schematic scheme of a distributed power distribution system control method of this embodiment. It should be noted that the technical scheme of the distributed power distribution system control system and the technical scheme of the above-mentioned distributed power distribution system control method belong to the same concept, and the details of the technical scheme of the distributed power distribution system control system in this embodiment that are not described in detail can all be referred to the description of the technical scheme of the above-mentioned distributed power distribution system control method.

[0082] This embodiment also provides a distributed power distribution system control system, including a data acquisition and calculation module, a first tracking and control module, and a second tracking and control module;

[0083] Specifically, the data acquisition and calculation module is used to collect first output data of the distributed power distribution system and calculate a first switching function;

[0084] Specifically, the first tracking control module is used to use the perturbation observation method to track the maximum power point if the value of the first switching function exceeds the first critical value when the system is started;

[0085] Specifically, the second tracking control module is used to stop using the disturbance observation method and switch to the sliding mode control mode to achieve tracking control of the maximum power point of distributed generation when the value of the first switching function is less than the first critical value.

[0086] The above-mentioned unit modules may be embedded in or independent of a processor in a computer device in the form of hardware, or may be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to the above-mentioned modules.

[0087] This embodiment also provides a computing device, which includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, an operator network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a distributed power distribution system control method is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a button, trackball or touchpad set on the housing of the computer device, or an external keyboard, touchpad or mouse.

[0088] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the method proposed in the above embodiment is implemented.

[0089] The storage medium proposed in this embodiment and the method proposed in the above embodiment belong to the same inventive concept. The technical details not fully described in this embodiment can be referred to the above embodiment, and this embodiment has the same beneficial effects as the above embodiment.

[0090] Through the above description of the implementation methods, the technicians in the relevant field can clearly understand that the present invention can be implemented by means of software and necessary general hardware, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ReadOnly, Memory, ROM), random access memory (RandomAccess Memory, RAM), flash memory (FLASH), hard disk or optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform the methods of various embodiments of the present invention.

[0091] Example 2

[0092] Reference Figure 2 , Figure 5 and Figure 6Based on the previous embodiment, this embodiment provides an application example of a distributed power distribution system control method and system to verify and illustrate the technical effects used in this method.

[0093] like Figure 2 The schematic diagram of the distributed power distribution system based on which the simulation of this embodiment is shown is a schematic diagram of the main circuit, and the output power is calculated by the output voltage and output current of the distributed power distribution system, and is further used to derive the first switching function; Figure 4 The figure shows the common bus voltage waveform of multiple parallel DGs in the distributed power distribution system control method proposed in this embodiment, where the red line is the traditional sliding mode control waveform and the blue line is the improved sliding mode control waveform. It can be seen from the comparison of simulation waveforms that the improved sliding mode control strategy makes the system bus voltage return to stability within 0.1s, reduces the steady-state response time, and improves the dynamic response speed of the system.

[0094] like Figure 5 The figure shows the output active power waveform of multiple parallel-connected DGs using the distributed distribution system control method proposed in this embodiment. From the comparison of the simulation waveforms, it can be seen that the improved sliding mode control strategy enables the system to catch up to the maximum power point within 0.1s, thereby improving the dynamic response speed of the system; and in steady state, the system oscillation is smaller, thereby reducing energy loss.

[0095] Therefore, it can be seen from the above experimental results that the improved sliding mode control of the present invention not only improves the stability and reliability of the system's grid-connected operation, but also realizes adaptive switching of the operating mode by combining the disturbance observation method, reduces the response time, and can better track and control the output, effectively suppress the fluctuation of the bus voltage, thereby reducing the steady-state error.

[0096] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0097] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application can 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 computer-usable program code. The scheme in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0098] 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 instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions 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.

[0099] These computer program instructions 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 instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0100] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0101] Although the preferred embodiments of the present application have been described, those skilled in the art may make other 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.

[0102] 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 distributed power distribution system control method, characterized in that: include: Collecting first output data of the distributed power distribution system and calculating a first switching function; If the value of the first switching function exceeds a first critical value when the system is started, a perturbation and observation method is used to track the maximum power point; Otherwise, the system switches to sliding mode control to achieve tracking control of the maximum power point of distributed generation.

2. The distributed power distribution system control method according to claim 1, characterized in that: The first switching function is a function derived according to the collected first output data of the distributed power distribution system, and is used to determine whether the system switches to disturbance observation control or sliding mode control.

3. The distributed power distribution system control method according to claim 2, characterized in that: If the value of the first switching function exceeds a first critical value when the system is started, the maximum power point tracking is performed using a perturbation observation method, including: Initializing relevant parameters of the disturbance observation method when the distributed power distribution system is started; Applying a first disturbance step size at a current operating point and changing an input condition of the distributed power distribution system; Calculate the current output power according to the collected first output data of the distributed power distribution system; Comparing the output power after the disturbance with the output power before the disturbance to determine whether the current output power is higher than the previous output power; If the output power after the disturbance increases, it is considered that the current disturbance direction is correct, and the working point continues to be adjusted in this direction. If the output power after the disturbance decreases, it is considered that the current disturbance direction is wrong, and the disturbance direction is changed and the working point is adjusted in the opposite direction. The above-mentioned process of disturbance, calculation, comparison and update is repeated continuously to gradually approach the maximum power point.

4. The distributed power distribution system control method according to claim 3, characterized in that: The parameters related to the initialization of the disturbance observation method when the distributed power distribution system is started include the initial working point, the converter duty cycle, and the duty cycle disturbance step size.

5. The distributed power distribution system control method according to claim 3, characterized in that: When the value of the first switching function is less than the first critical value, the system determines that it is close to the maximum power point. At this time, the disturbance observation method is stopped and the sliding mode control mode is switched to ensure steady-state accuracy.

6. The distributed power distribution system control method according to claim 1, characterized in that: The system switches to sliding mode control to implement tracking control of the maximum power point of distributed generation, including adjusting the converter duty cycle to ensure that the system has the best steady-state accuracy when tracking the maximum power point.

7. The distributed power distribution system control method according to claim 6, characterized in that: The adjusting the duty cycle of the converter comprises: When the value of the first switching function is less than the first critical value, the system switches to the sliding mode control mode and continues to determine whether the value of the first switching function is greater than 0; If the value of the first switching function is greater than 0, the duty cycle of the converter is adjusted to D1 = D0 + k x If the value of the first switching function is less than or equal to 0, the duty cycle of the converter is adjusted to D1 = D0-k x , where D1 represents the duty cycle of the converter after adjustment, D0 represents the duty cycle of the converter before adjustment, k x represents the equivalent duty cycle disturbance step size of the sliding mode control mode; After the converter duty cycle is adjusted, the output voltage U(k) and the output current I(k) are updated to the values ​​of the current cycle, and secondary feedback is performed to prepare for the next iteration.

8. A system using the distributed power distribution system control method according to any one of claims 1 to 7, characterized in that: include: A data acquisition and calculation module, used for acquiring first output data of the distributed power distribution system and calculating a first switching function; A first tracking control module, configured to use a perturbation observation method to track the maximum power point if the value of the first switching function exceeds a first critical value when the system is started; The second tracking control module is used to stop using the disturbance observation method and switch to the sliding mode control mode to achieve tracking control of the maximum power point of distributed generation when the value of the first switching function is less than the first critical value and the system determines that it is close to the maximum power point.

9. An electronic device, comprising: Memory and processor; The memory is used to store computer executable instructions, and the processor is used to execute the computer executable instructions. When the computer executable instructions are executed by the processor, the steps of the distributed power distribution system control method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions, when executed by a processor, implement the steps of the distributed power distribution system control method according to any one of claims 1 to 7.

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