Diesel-storage hybrid power anti-overload system and device based on network-forming inverter, and medium

Abstract

The invention provides a diesel-storage hybrid power anti-overload system and device based on a network-forming inverter, and a medium. A pre-synchronization module realizes seamless switching between a VSG mode and a PQ mode based on dynamic voltage amplitude matching, phase-locked loop frequency synchronization and phase real-time alignment technologies; the hardware current limiting module adopts high-speed current monitoring and hardware-level protection logic to cut off an overcurrent pulse in real time and prevent a power device from failing due to transient impact; the power suppression module optimizes the power distribution of the diesel generator and the energy storage by judging an overload threshold value and a steady state recovery condition in real time; the logic judgment module coordinates the diesel generator dynamic frequency modulation and energy storage mode switching, the diesel generator preferentially bears the transient power difference when the load suddenly changes, and the energy storage mode is seamlessly switched to the network construction mode after the system recovers the steady state; according to the system, through software and hardware full-link collaborative design, the problems of transient overload and mode switching instability of the diesel storage system are solved, and the stability and energy efficiency of the diesel storage hybrid power system are improved.

Description

Technical Field

[0001] The present invention relates to the field of diesel - energy storage hybrid power systems, and more particularly, to a diesel - energy storage hybrid anti - overload system, device, and medium based on a grid - forming inverter. Background Art

[0002] In current diesel - energy storage hybrid power systems, the coordinated control of the inverter and the diesel generator mainly relies on the PQ current source mode and the grid - forming VSG control mode. In the PQ mode, the power source is controlled to output specific active power (P) and reactive power (Q), and the power is controlled by adjusting the magnitude and phase of the output current. The grid - forming VSG (Virtual Synchronous Generator) mode is a control strategy that simulates the operating characteristics of a traditional synchronous generator, and controls the output voltage, frequency, and power by controlling the virtual rotor motion equation.

[0003] For the PQ mode, it relies on the phase - locked loop to track the phase, and is vulnerable to grid interference under a weak grid, resulting in phase error and power angle instability; it lacks the ability of active frequency and voltage regulation, and relies on the diesel generator to compensate for the power gap when the load changes, with a lag in dynamic response; the current limiting mechanism is insufficient, and voltage dips and system collapse are likely to occur during overload.

[0004] For the VSG mode, the virtual inertia does not match the mechanical inertia of the diesel generator, resulting in energy storage overload after the frequency modulation ability is exhausted; the reactive power droop characteristic conflicts with the diesel generator's regulation coefficient, leading to reactive power distribution imbalance and stator overload risk; the economic optimization strategy weakens the transient load - carrying ability and exacerbates the system vulnerability; In addition, both types of solutions have power oscillations and transient instability during mode switching, and lack hardware - level overload protection, making it difficult to handle short - circuit or high - impact load scenarios. Therefore, there is an urgent need for a coordinated control solution that integrates hardware protection, dynamic frequency modulation, and seamless switching to improve the stability and energy efficiency of the diesel - energy storage hybrid power system. Summary of the Invention

[0005] In view of the above problems, the purpose of the present invention is to provide a diesel - energy storage hybrid anti - overload system, device, and medium based on a grid - forming inverter. The seamless switching between the VSG mode and the PQ mode is achieved through a pre - synchronization module; the power devices are prevented from failing due to transient impacts through a hardware current - limiting module; the power distribution between the diesel generator and the energy storage is optimized through a power suppression module; and the logic determination module coordinates the dynamic frequency modulation of the diesel generator and the mode switching of the energy storage. Through the collaborative design of the entire software and hardware link, the present invention optimizes the problems of transient overload and mode - switching instability in the diesel - energy storage system, and improves the stability and energy efficiency of the diesel - energy storage hybrid power system.

[0006] The first aspect of the present invention provides a diesel - energy storage hybrid anti - overload system based on a grid - forming inverter, and the system includes: A pre-synchronization module, which is used to achieve seamless switching between the VSG mode and the PQ mode by dynamically matching the grid voltage amplitude information, frequency information and phase information; A hardware current limiting module, which, based on real-time current monitoring and a hardware-level protection mechanism, truncates the overcurrent pulse when it determines an overcurrent state; A power suppression module, which is used to determine the overload threshold and the steady-state recovery condition according to the frequency information and the power information, and adjust the distribution of the energy storage power and the diesel generator power; A logic determination module, which is used to coordinate the dynamic frequency modulation of the diesel generator and the switching of the grid mode, and preferentially have the diesel generator bear the transient power difference when the load suddenly changes, and switch from the PQ mode to the VSG mode after the system returns to the steady state.

[0007] In this solution, the pre-synchronization module specifically includes: A voltage matching unit, which adjusts the output voltage amplitude information through closed-loop control to make the deviation value between the voltage amplitude information and the target grid voltage amplitude less than a preset voltage deviation threshold; A frequency synchronization unit, which measures the grid frequency information in real time through a phase-locked loop technology, and dynamically corrects the internal reference frequency information of the VSG according to the grid frequency information to make the deviation value between the grid frequency information and the reference frequency information less than a preset frequency deviation threshold; A phase alignment unit, which is used to detect the grid phase information in real time and adjust the output phase angle of the inverter through a first PID controller.

[0008] In this solution, the hardware current limiting module specifically includes: A current acquisition unit, which, based on a high-precision current sensor, obtains the output current information of the inverter according to a preset first sampling frequency, wherein the high-precision current sensor includes a Hall sensor or a shunt resistance circuit; A high-speed comparison unit, which, through a hardware comparator circuit, compares the output current information with a preset reference current threshold at a preset first comparison frequency to obtain current comparison information; A hardware protection unit, which triggers a hardware protection logic based on the current comparison information, wherein the hardware protection logic is desaturation protection; if the output current information is greater than the reference current threshold, the hardware protection logic is triggered according to a preset first switching period to turn off the power device.

[0009] In this solution, the hardware current limiting module further includes: A self-recovery unit, which performs self-recovery steps: In the next first switching period, turn on the power device; Judge whether the output current information is greater than the reference current threshold; If so, trigger the per-cycle current limiting operation mode; If not, keep the power device conducting.

[0010] In this solution, the power suppression module specifically includes: An overload determination unit that determines whether the inverter is in an overload state based on the output voltage information and output current information of the inverter; A steady-state recovery unit that determines whether the output of the inverter has recovered to a steady state based on the output frequency information of the inverter.

[0011] In this solution, the overload determination unit executes an overload determination process, specifically: Obtain output power information according to the output voltage amplitude information and the output current information; According to the output power information and the preset rated power information, obtain power ratio information through a preset sliding window averaging algorithm; Record the continuous sampling times information when the power ratio information continuously exceeds the preset power ratio threshold range; When the continuous sampling times information exceeds the preset times threshold, trigger current limiting protection to reduce the output current information of the inverter.

[0012] In this solution, the steady-state recovery unit executes a steady-state recovery process, specifically: Process the output frequency information based on a preset low-pass filter to obtain filtered frequency information; Obtain the internal reference frequency information of the VSG; According to the reference frequency information, obtain the steady-state frequency dead zone range; Judge whether the filtered frequency information is within the steady-state frequency dead zone range; If so, switch the grid mode to the VSG mode.

[0013] In this solution, the logic determination module specifically includes: A diesel generator regulation unit for adjusting the opening of the diesel generator fuel valve through a second PID controller according to the output frequency information of the inverter; A grid mode switching unit that switches the grid mode to the PQ mode or the VSG mode based on the output frequency change rate and output power deviation of the inverter.

[0014] The second aspect of the present invention provides an electronic device, which includes a processor, a memory, a communication interface, and a communication bus. Among them, the processor, the communication interface, and the memory complete communication with each other through the communication bus; the memory is used to store a computer program; when the processor executes the program stored on the memory, it realizes the operation steps of the above-mentioned diesel storage hybrid anti-overload system based on a grid-forming inverter.

[0015] In a third aspect of the present invention, a computer-readable storage medium is provided. The computer-readable storage medium includes a program for a diesel-storage hybrid anti-overload system based on a grid-forming inverter. When the program for the diesel-storage hybrid anti-overload system based on the grid-forming inverter is executed by a processor, the steps of the diesel-storage hybrid anti-overload system as described in any one of the above are implemented.

[0016] The present invention provides a diesel-storage hybrid anti-overload system, device, and medium based on a grid-forming inverter. The pre-synchronization module realizes seamless switching between the VSG mode and the PQ mode based on dynamic voltage amplitude matching, phase-locked loop frequency synchronization, and real-time phase alignment technology; the hardware current limiting module uses high-speed current monitoring and hardware-level protection logic to truncate overcurrent pulses in real time to prevent power devices from failing due to transient impacts; the power suppression module optimizes the power distribution between the diesel generator and the energy storage by real-time determining the overload threshold and steady-state recovery conditions; the logic determination module coordinates the dynamic frequency modulation of the diesel generator and the energy storage mode switching, and preferentially allows the diesel generator to bear the transient power difference when the load changes suddenly, and seamlessly switches the energy storage to the grid-forming mode after the system returns to the steady state; through the collaborative design of the entire software and hardware link, this system optimizes the problems of transient overload and mode switching instability of the diesel-storage system, and improves the stability and energy efficiency of the diesel-storage hybrid system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope.

[0018] Figure 1 Shows a schematic structural diagram of a diesel-storage hybrid anti-overload system based on a grid-forming inverter of the present invention; Figure 2 Shows a schematic structural diagram of the synchronization module provided by an embodiment of the present invention; Figure 3 Shows a schematic structural diagram of the hardware current limiting module provided by an embodiment of the present invention; Figure 4 Shows a schematic structural diagram of the power suppression module provided by an embodiment of the present invention; Figure 5 Shows a flowchart of the overload determination unit provided by an embodiment of the present invention for performing overload determination; Figure 6 Shows a flowchart of the steady-state recovery unit provided by an embodiment of the present invention for performing steady-state recovery; Figure 7 Shows a diesel-storage hybrid anti-overload device based on a grid-forming inverter provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0020] Unless otherwise defined, all terms (including technical and scientific terms) used in the embodiments of the present invention have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. It should also be understood that terms such as those defined in a general dictionary should be interpreted as having a meaning consistent with their meaning in the context of the related art, and should not be interpreted in an idealized or overly formal sense, unless explicitly defined in the embodiments of the present invention.

[0021] The "first", "second" and similar terms used in the embodiments of the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. Terms such as "a", "an" or "the" do not denote a quantity limitation either, but mean that there is at least one. Similarly, words such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. The terms "connected" or "coupled" and the like are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The steps before or after the methods in the embodiments of the present invention do not necessarily need to be carried out precisely in sequence. On the contrary, they can be carried out in reverse order or various steps can be processed simultaneously. At the same time, other operations can also be added to these processes, or one or several steps can be removed from these processes.

[0022] In addition, the functional modules in each embodiment of the present invention can be integrated together to form an independent part, or each module can exist alone, or two or more modules can be integrated to form an independent part.

[0023] Figure 1 The structural schematic diagram of a diesel - energy - storage hybrid anti - overload system based on a grid - forming inverter of the present invention is shown.

[0024] As Figure 1 shown, in the first aspect of the present invention, a diesel - energy - storage hybrid anti - overload system 10 based on a grid - forming inverter is disclosed, and the system includes: A pre - synchronization module 101, configured to achieve seamless switching between the VSG mode and the PQ mode by dynamically matching the grid voltage amplitude information, frequency information, and phase information; The hardware current limiting module 102, based on real-time current monitoring and a hardware-level protection mechanism, truncates the overcurrent pulse when it determines an overcurrent state. The power suppression module 103 is used to determine the overload threshold and steady-state recovery conditions based on frequency information and power information, and adjust the distribution of energy storage power and diesel generator power. The logic determination module 104 is used to coordinate the dynamic frequency modulation of the diesel generator and the switching of the grid mode. When the load suddenly changes, the diesel generator preferentially bears the transient power difference. After the system returns to a steady state, it switches from the PQ mode to the VSG mode.

[0025] It should be noted that in the VSG (Virtual Synchronous Generator) grid-forming technology, the pre-synchronization module is mainly used in front of the inverter to ensure that the output voltage, frequency, and phase of the inverter are precisely matched with the grid parameters, so as to achieve seamless switching between the VSG mode and the PQ mode, that is, to achieve smooth and seamless grid connection operation. The hardware current limiting module is a high-speed current protection mechanism based on a hardware circuit. It monitors the output current in real time during each switching cycle of the inverter. When the detected current exceeds the preset threshold, it immediately forcibly limits the current amplitude through hardware logic to prevent power devices from being damaged due to overcurrent. The power suppression module triggers current limiting protection when the output power of the inverter is greater than the rated power, indicating power overload; when it determines that the steady state is restored based on the output frequency of the inverter, it switches to the VSG mode and dynamically distributes the energy storage power and diesel generator power; it avoids misjudgment through dynamic power calculation and filtering algorithms, and adopts a steady-state recovery logic to improve the automation level of the system. The logic determination module dynamically adjusts the fuel valve opening of the diesel generator based on the output state of the inverter, automatically switches the grid mode, thereby reducing energy consumption while supplying the load, and taking into account both the power supply stability and energy efficiency of the system.

[0026] Figure 2 The structural schematic diagram of the synchronization module provided by the embodiment of the present invention is shown.

[0027] According to the embodiment of the present invention, as Figure 2 shown, the pre-synchronization module 101 specifically includes: The voltage matching unit 201 adjusts the output voltage amplitude information through closed-loop control to make the deviation value between the voltage amplitude information and the target grid voltage amplitude less than the preset voltage deviation threshold. The frequency synchronization unit 202 measures the grid frequency information in real time through the phase-locked loop technology, and dynamically corrects the internal reference frequency information of the VSG according to the grid frequency information to make the deviation value between the grid frequency information and the reference frequency information less than the preset frequency deviation threshold. The phase alignment unit 203 is used to detect the grid phase information in real time and adjust the output phase angle of the inverter through the first PID controller.

[0028] It should be noted that the voltage matching unit is used to adjust the amplitude of the inverter output voltage. Based on the difference between the replicated output voltage and the amplitude of the target grid voltage, a closed-loop control algorithm is adopted to make the amplitude of the output voltage approach the target grid voltage. Among them, the closed-loop regulation is a PI regulation algorithm. The frequency synchronization unit is used to adjust the frequency of the inverter output voltage. Based on the phase-locked loop (PLL) technology, it measures the frequency of the power grid in real time and dynamically corrects the internal reference frequency of the VSG according to the grid frequency. Then, based on the reference frequency, it adjusts the frequency of the inverter output voltage, so that the frequency of the inverter output voltage approaches the grid frequency. The phase alignment unit is used to adjust the phase angle of the inverter output voltage. According to the deviation between the measured grid phase angle and the phase angle of the inverter output voltage in real time, a control quantity is obtained by using a first PID controller, and the inverter output is adjusted based on the control quantity to make the phase angle of its output voltage approach the grid phase angle. Among them, as an implementation manner, the first PID controller adopts a PI regulation algorithm.

[0029] Figure 3 The structural schematic diagram of the hardware current limiting module provided by the embodiment of the present invention is shown.

[0030] According to the embodiment of the present invention, as Figure 3 shown, the hardware current limiting module 102 specifically includes: A current acquisition unit 301, based on a high-precision current sensor, obtains the output current information of the inverter according to a preset first sampling frequency. Among them, the high-precision current sensor includes a Hall sensor or a shunt resistance circuit; A high-speed comparison unit 302, through a hardware comparator circuit, compares the output current information with a preset reference current threshold at a preset first comparison frequency to obtain current comparison information; A hardware protection unit 303 triggers a hardware protection logic based on the current comparison information. The hardware protection logic is desaturation protection. If the output current information is greater than the reference current threshold, the hardware protection logic is triggered according to a preset first switching period, and the power device is turned off.

[0031] It should be noted that the current acquisition unit acquires the inverter output current signal, which is conditioned by the differential amplifier circuit and then input to the high-speed comparator circuit of the high-speed comparison unit. The comparison result is input to the hardware protection unit. The current acquisition unit detects the output current of the inverter based on a preset current acquisition frequency through a high-precision current sensor, such as a Hall sensor or a shunt resistance circuit. The high-speed comparison unit includes a hardware comparator circuit and a trigger circuit, which performs a comparison of the amplitude between the inverter current signal and a preset reference current threshold signal based on a preset comparison execution frequency to obtain current comparison information. In practical applications, the first sampling frequency and the first comparison frequency are the same value. The hardware protection unit reads the current comparison result based on the switch switching period. If the output current information is greater than the reference current threshold, indicating that the inverter output current is too high and there is an overcurrent phenomenon, it triggers the desaturation protection (DESAT, a mechanism for protecting power devices of a power transistor) of the drive chip, immediately turns off the power device within the current switch switching period, avoids further increase of the current, and prevents device damage, achieving the purpose of improving the operating safety of the system.

[0032] According to an embodiment of the present invention, the hardware current limiting module further includes: A self-recovery unit that performs self-recovery steps: In the next first switching period, turn on the power device; Determine whether the output current information is greater than the reference current threshold; If so, trigger the per-cycle current limiting operation mode; If not, keep the power device turned on.

[0033] It should be noted that this embodiment provides a self-recovery mechanism. After the power device is turned off, the self-recovery unit attempts to turn it on again in the next switching cycle. If the current returns to normal, the system continues to operate; if the overcurrent persists, it triggers the per-cycle current limiting loop until the fault is eliminated, further improving the automation degree of the system operation. The per-cycle current limiting operation mode is an operation that performs a current limiting - recovery cycle switch based on the wave generation period.

[0034] Figure 4 Shows the structural schematic diagram of the power suppression module provided by an embodiment of the present invention.

[0035] According to an embodiment of the present invention, as Figure 4 shown, the power suppression module 103 specifically includes: An overload determination unit 401 that determines whether the inverter is in an overload state based on the output voltage information and output current information of the inverter; A steady-state recovery unit 402 that determines whether the inverter output has recovered to the steady state based on the output frequency information of the inverter.

[0036] It should be noted that the overload determination unit is used to determine whether the transient output power of the inverter is too high. When it is determined to be in an overload state, current limiting protection is triggered to reduce the output current of the inverter, thereby reducing the power and achieving the purpose of protecting the system. The steady-state recovery unit determines whether the filtered frequency is within the set steady-state frequency range based on the output frequency after the inverter adjusts the output and filters out high-frequency noise; if so, it indicates that the inverter system has recovered to the steady state, and the grid mode is switched to the VSG mode, and the energy storage power and diesel generator power are dynamically allocated based on the operating state of the inverter according to the VSG mode.

[0037] Figure 5 The flowchart showing the overload determination performed by the overload determination unit provided in the embodiment of the present invention is shown.

[0038] According to the embodiment of the present invention, as Figure 5 shown, the overload determination unit performs the overload determination process, specifically as follows: S502, obtain output power information according to the output voltage amplitude information and the output current information; S504, obtain power ratio information according to the output power information and the preset rated power information through the preset sliding window average algorithm; S506, record the continuous sampling times information of the power ratio information continuously exceeding the preset power ratio threshold range; S508, when the continuous sampling times information exceeds the preset times threshold, trigger current limiting protection to reduce the output current information of the inverter.

[0039] It should be noted that this embodiment provides an overload determination process to determine whether there is an overload based on the output power of the inverter. First, based on the instantaneous output voltage amplitude and output current of the inverter, the instantaneous output power is obtained. Secondly, based on at least two instantaneous output powers, the instantaneous average power is obtained based on the preset sliding window average algorithm to eliminate noise disturbance; then, the ratio operation is performed between the instantaneous average power and the preset rated power to obtain the power ratio. Then, record the number of consecutive sampling periods in which the power ratio continuously exceeds the preset power ratio threshold. If the continuous sampling times information exceeds the preset times threshold, it indicates that the output of the inverter is in a stable overload state. At this time, current limiting is triggered and switched to the PQ mode, and the output current of the inverter is reduced to achieve the purpose of protecting the inverter system.

[0040] Figure 6 The flowchart showing the steady-state recovery performed by the steady-state recovery unit provided in the embodiment of the present invention is shown.

[0041] According to the embodiment of the present invention, as Figure 6 shown, the steady-state recovery unit performs the steady-state recovery process, specifically as follows: S602. Process the output frequency information based on a preset low-pass filter to obtain filtered frequency information. S604. Obtain the internal reference frequency information of the VSG. S606. Determine the steady-state frequency dead zone range according to the reference frequency information. S608. Determine whether the filtered frequency information is within the steady-state frequency dead zone range. S610. If so, switch the grid mode to the VSG mode.

[0042] It should be noted that this embodiment provides a steady-state recovery process, which determines whether the inverter system has recovered to the steady state based on the frequency of the inverter output voltage. First, based on a preset low-pass filter, including but not limited to Butterworth low-pass filter, process the frequency signal of the inverter output voltage to obtain filtered frequency information to eliminate high-frequency noise. Then, determine the dead zone range of the steady-state frequency according to the internal reference frequency of the VSG set by the frequency synchronization unit; where the dead zone range represents the allowable floating frequency range of the output frequency. Finally, when the filtered frequency information is within the steady-state frequency dead zone range, it means that the inverter system has recovered to the steady state, and at this time, the grid mode is switched to the VSG mode.

[0043] According to the embodiment of the present invention, the logic determination module specifically includes: The diesel generator regulation unit is used to adjust the opening of the diesel generator fuel valve through the second PID controller according to the output frequency information of the inverter. The grid mode switching unit switches the grid mode to the PQ mode or the VSG mode based on the output frequency change rate and output power deviation of the inverter.

[0044] It should be noted that the diesel generator regulation unit dynamically adjusts the opening of the fuel valve through the second PID controller based on the frequency deviation value between the output frequency of the inverter and the internal reference frequency of the VSG to achieve the purpose of adjusting the power of the diesel generator; where the second PID controller is a fuzzy PID control algorithm. Dynamically adjust the power of the diesel generator through the fuzzy PID control algorithm to ensure system power supply while improving energy efficiency. The grid mode switching unit is used to switch the grid mode. Based on the weighted calculation index of the output frequency change rate and output power deviation of the inverter, when the index exceeds the preset threshold, it is switched to the PQ mode; otherwise, it is switched to the VSG mode.

[0045] It is worth mentioning that it further includes: The dynamic association model collaboratively adjusts the opening of the diesel generator fuel valve based on the virtual inertia parameter and damping coefficient of the VSG.

[0046] It should be noted that the inertia of the diesel generator rotor is measured in real time by a rotational speed sensor, which is used to dynamically adjust the virtual inertia parameter of the VSG. The oscillation amplitude of the diesel generator system is monitored in real time based on frequency analysis, which is used to adjust the damping coefficient of the VSG. According to the virtual inertia parameter and the damping coefficient, the opening of the diesel generator fuel valve is adjusted synergistically to optimize the damping characteristics of the system and reduce the risk of instability.

[0047] It is worth mentioning that it also includes: A feed-forward control unit, which is used to detect the load current information in real time. By analyzing the change trend of the load current information, it switches to the PQ mode and operates in a per-cycle current limiting mode based on the change trend.

[0048] It should be noted that when applied to a high-impact load scenario, the inverter detects the change trend of the load current through the feed-forward control unit, and obtains the change slope based on the derivative of the load current. If the change slope exceeds a preset slope threshold, it switches to the PQ mode and improves the impact load absorption capacity through the per-cycle current limiting operation mode, thereby improving the system security.

[0049] Figure 7 The flowchart showing the steady-state recovery unit of the present invention embodiment performing steady-state recovery is shown.

[0050] As Figure 7 shown, the second aspect of the present invention provides an electronic device, which includes a processor 701, a memory 702, a communication interface 703, and a communication bus 704. Among them, the processor, the communication interface, and the memory complete communication with each other through the communication bus; the memory is used to store a computer program; when the processor executes the program stored on the memory, it realizes the operation steps of the diesel storage hybrid anti-overload system based on the grid-forming inverter described in any one of the above.

[0051] The third aspect of the present invention provides a computer-readable storage medium, which includes a program for a diesel storage hybrid anti-overload system based on a grid-forming inverter. When the program for the diesel storage hybrid anti-overload system based on the grid-forming inverter is executed by a processor, it realizes the steps of the diesel storage hybrid anti-overload system based on the grid-forming inverter described in any one of the above.

[0052] In summary, the present invention provides a diesel - energy - storage hybrid anti - overload system, device, and medium based on a grid - forming inverter. The pre - synchronization module realizes seamless switching between the VSG mode and the PQ mode based on dynamic voltage amplitude matching, phase - locked loop frequency synchronization, and real - time phase alignment technology; the hardware current - limiting module uses high - speed current monitoring and hardware - level protection logic to truncate over - current pulses in real time to prevent power devices from failing due to transient impacts; the power suppression module optimizes the power distribution between the diesel generator and the energy storage by real - time determining the overload threshold and steady - state recovery conditions; the logic determination module coordinates the dynamic frequency modulation of the diesel generator and the energy - storage mode switching, preferentially allowing the diesel generator to bear the transient power difference during load mutations, and seamlessly switching the energy storage to the grid - forming mode after the system resumes steady state. Through the collaborative design of the entire software - hardware link, this system optimizes the problems of transient overload and mode - switching instability in the diesel - energy - storage system, and improves the stability and energy efficiency of the diesel - energy - storage hybrid system.

[0053] If the above - mentioned functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer - readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or a part of this technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: USB flash drives, mobile hard disks, read - only memories (ROMs), random access memories (RAMs), magnetic disks, or optical discs, etc., which can store program codes.

[0054] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc., made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A diesel-storage hybrid overload protection system based on a grid-connected inverter, characterized in that: The system comprises: Pre-synchronization module, used to achieve seamless switching between VSG mode and PQ mode by dynamically matching grid voltage amplitude information, frequency information and phase information; The hardware current limiting module, based on real-time current monitoring and hardware-level protection mechanism, cuts off the overcurrent pulse when it is judged to be in overcurrent state; The power suppression module is used to determine the overload threshold and steady-state recovery conditions based on frequency information and power information, and adjust the distribution of energy storage power and diesel generator power; The logic judgment module is used to coordinate the switching between the dynamic frequency regulation of the diesel generator and the grid mode. When the load suddenly changes, the diesel generator will take the priority to bear the transient power difference, and switch from PQ mode to VSG mode after the system returns to steady state.

2. According to claim 1, a diesel-storage hybrid overload protection system based on a grid-connected inverter is characterized in that: The pre-synchronization module specifically includes: The voltage matching unit adjusts the output voltage amplitude information through closed-loop control so that the deviation between the voltage amplitude information and the target grid voltage amplitude is less than a preset voltage deviation threshold; The frequency synchronization unit measures the grid frequency information in real time through the phase-locked loop technology, and dynamically corrects the VSG internal reference frequency information according to the grid frequency information, so that the deviation value between the grid frequency information and the reference frequency information is less than the preset frequency deviation threshold; The phase alignment unit is used to detect the grid phase information in real time and adjust the output phase angle of the inverter through the first PID controller.

3. According to claim 1, a diesel-storage hybrid overload protection system based on a grid-connected inverter is characterized in that: The hardware current limiting module specifically includes: A current acquisition unit, based on a high-precision current sensor, obtains output current information of the inverter according to a preset first sampling frequency, wherein the high-precision current sensor includes a Hall sensor or a shunt resistor circuit; A high-speed comparison unit compares the output current information with a preset reference current threshold at a high speed according to a preset first comparison frequency through a hardware comparator circuit to obtain current comparison information; A hardware protection unit triggers hardware protection logic based on the current comparison information, wherein the hardware protection logic is desaturation protection; if the output current information is greater than the reference current threshold, the hardware protection logic is triggered according to a preset first switching cycle to shut down the power device.

4. According to claim 3, a diesel-storage hybrid overload protection system based on a grid-connected inverter is characterized in that: The hardware current limiting module also includes: Self-recovery unit, performs self-recovery steps: In the next first switching cycle, turning on the power device; Determining whether the output current information is greater than the reference current threshold; If so, the wave-by-wave current limiting operation mode is triggered; If not, the power device remains turned on.

5. The diesel-storage hybrid overload protection system based on a grid-connected inverter according to claim 1 is characterized in that: The power suppression module specifically includes: An overload determination unit, which determines whether the inverter is in an overload state based on output voltage information and output current information of the inverter; The steady-state recovery unit determines whether the inverter output is recovered to a steady state based on the output frequency information of the inverter.

6. The diesel-storage hybrid overload protection system based on a grid-connected inverter according to claim 5 is characterized in that: The overload determination unit performs an overload determination process, specifically: Obtaining output power information according to the output voltage amplitude information and the output current information; According to the output power information and the preset rated power information, power ratio information is obtained by using a preset sliding window averaging algorithm; Recording the number of consecutive sampling times when the power ratio information exceeds a preset power ratio threshold range; When the continuous sampling number information exceeds a preset number threshold, the current limiting protection is triggered to reduce the output current information of the inverter.

7. The diesel-storage hybrid overload protection system based on a grid-connected inverter according to claim 5 is characterized in that: The steady-state recovery unit performs a steady-state recovery process, specifically: Processing the output frequency information based on a preset low-pass filter to obtain filtered frequency information; Get VSG internal reference frequency information; According to the reference frequency information, a steady-state frequency dead zone range is obtained; Determine whether the filtering frequency information is within the steady-state frequency dead zone; If yes, the grid mode is switched to VSG mode.

8. The diesel-storage hybrid overload protection system based on a grid-connected inverter according to claim 1 is characterized in that: The logic determination module specifically includes: A diesel engine regulating unit, used for adjusting the diesel engine fuel valve opening through a second PID controller according to the output frequency information of the inverter; The grid mode switching unit switches the grid mode to the PQ mode or the VSG mode based on the output frequency change rate and the output power deviation of the inverter.

9. An electronic device, characterized in that: It includes a processor, a memory, a communication interface and a communication bus, wherein the processor, the communication interface and the memory communicate with each other via the communication bus; Memory, used to store computer programs; The processor is used to implement the operation steps of the diesel-storage hybrid overload protection system based on the grid-type inverter as described in any one of claims 1 to 8 when executing the program stored in the memory.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: The computer-readable storage medium includes a diesel-storage hybrid anti-overload system program based on a grid-type inverter. When the diesel-storage hybrid anti-overload system program based on a grid-type inverter is executed by a processor, the operating steps of the diesel-storage hybrid anti-overload system based on a grid-type inverter as described in any one of claims 1 to 8 are implemented.

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