Control system and method of power grid inverter

Abstract

The invention discloses a control system and method for a power grid inverter, and relates to the technical field of inverter control, and the system comprises a virtual synchronous generator and a control system. The virtual synchronous generator is used for controlling the frequency, the phase and the amplitude of an inverter in a power grid through the simulation synchronous generator; the control system is used for adjusting the frequency, the phase and the amplitude of the inverter in real time through the virtual synchronous generator according to the real-time operation state and the real-time external disturbance condition of the power grid. According to the invention, the response speed of the inverter to frequency and voltage changes can be improved, the stability is enhanced, and the adaptability to factors such as load changes and power grid faults can also be improved.

Description

Technical Field

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

[0002] As the penetration rate of distributed energy in the power grid increases, the inverters in the power grid (such as microgrids) lack the necessary inertia and damping, which seriously endangers the stability of the power system of the power grid. In order to solve this problem, a virtual synchronous generator (VSG) is often used to simulate the rotational inertia and damping of the synchronous generator (SG). However, the constant rotational inertia and damping coefficient cannot guarantee the power and frequency regulation performance of the inverter, nor can it guarantee the fast and stable response of the inverter frequency and power when disturbances occur. In addition, it has the following disadvantages:

[0003] 1) Lack of flexibility: Traditional virtual synchronous generator control lacks flexibility and adaptability, and cannot adjust control strategies and parameters according to real-time power system operating status and environmental changes, resulting in slow system response and poor stability.

[0004] 2) Reliance on experience-based adjustment: Traditional virtual synchronous generator control often relies on experience-based adjustment of parameters, requiring operators to have certain experience and skills to perform effective parameter setting and adjustment, which increases labor costs and the risk of errors.

[0005] 3) Difficulty in coping with complex environments: Traditional virtual synchronous generator control may have difficulty coping with complex and changing environments and operating conditions, cannot achieve optimal control, and is prone to stability problems when facing system failures, load changes or external disturbances.

[0006] 4) Performance limitations: Traditional virtual synchronous generator control may be limited by fixed control algorithms and parameters, and cannot fully utilize the resources and advantages of the system, resulting in performance limitations and inefficiency. Summary of the invention

[0007] The technical problem to be solved by the present invention is to address the deficiencies of the prior art and specifically provide a control system and method for a power grid inverter, which are as follows:

[0008] 1) In the first aspect, the present invention provides a control system for a power grid inverter, and the specific technical solution is as follows:

[0009] Includes virtual synchronous generator and control system;

[0010] The virtual synchronous generator is used to: control the frequency, phase and amplitude of the inverter in the power grid by simulating the synchronous generator;

[0011] The control system is used to: According to the real-time operating status of the power grid and the real-time external disturbance, the frequency, phase and amplitude of the inverter are adjusted in real time through the virtual synchronous generator.

[0012] The beneficial effects of a control system of a power grid inverter provided by the present invention are as follows:

[0013] According to the real-time operating status of the power grid and the real-time external disturbance, the frequency, phase and amplitude of the inverter are adjusted in real time through the virtual synchronous generator, which improves the inverter's response speed to frequency and voltage changes, enhances stability, and improves its adaptability to factors such as load changes and power grid failures.

[0014] Based on the above solution, the control system of a power grid inverter of the present invention can also be improved as follows.

[0015] Furthermore, it also includes a camera module and a deep learning network algorithm module;

[0016] The camera module is used to: collect images of the inverter mainboard and send them to the deep learning network algorithm module;

[0017] The deep learning network algorithm module is used to: identify the image of the inverter mainboard and determine whether there are damaged components in the inverter mainboard.

[0018] Furthermore, it also includes a target detection and circuit breaker module, which is used to: when the deep learning network algorithm module identifies damaged components, implement circuit breaking measures on the circuit where the damaged components are located.

[0019] Furthermore, it also includes a temperature sensing device; the temperature sensing device is used to collect the temperature of the inverter mainboard and send it to the control system.

[0020] Furthermore, the control system is also used to trigger a fire extinguishing mechanism when the temperature of the inverter mainboard exceeds a preset temperature threshold.

[0021] 2) In a second aspect, the present invention further provides a control method for a power grid inverter, and the specific technical solution is as follows:

[0022] Obtain the real-time operating status and external disturbance conditions of the power grid where the inverter is located;

[0023] According to the real-time operating status of the power grid and the real-time external disturbance, the frequency, phase and amplitude of the inverter are adjusted in real time through the virtual synchronous generator.

[0024] On the basis of the above solution, the control method of a power grid inverter of the present invention can be further improved as follows.

[0025] Furthermore, it also includes:

[0026] Capture the image of the inverter mainboard through the camera module;

[0027] The image of the inverter mainboard is identified to determine whether there are damaged components in the inverter mainboard.

[0028] Furthermore, it also includes:

[0029] When damaged components are identified, circuit breaking measures are implemented on the circuit where the damaged components are located through the target detection and circuit breaker module.

[0030] Furthermore, it also includes:

[0031] The temperature of the inverter mainboard is collected through a temperature sensing device.

[0032] Furthermore, it also includes:

[0033] When the temperature of the inverter's mainboard exceeds the preset temperature threshold, the fire extinguishing mechanism is triggered.

[0034] It should be noted that the beneficial effects achieved by the technical solution of the second aspect of the present invention and the corresponding possible implementation methods can be found in the above-mentioned technical effects of the first aspect and its corresponding possible implementation methods, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0036] Figure 1 A schematic structural diagram of a control system of a power grid inverter according to an embodiment of the present invention;

[0037] Figure 2 Schematic diagram for visual identification and troubleshooting;

[0038] Figure 3 The present invention is a flowchart of a method for controlling a power grid inverter according to an embodiment of the present invention. DETAILED DESCRIPTION

[0039] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0040] like Figure 1 As shown, a control system of a power grid inverter according to an embodiment of the present invention includes a virtual synchronous generator and a control system;

[0041] The virtual synchronous generator is used to: control the frequency, phase and amplitude of the inverter in the power grid by simulating the synchronous generator;

[0042] The virtual synchronous generator maintains the stability of the inverter by simulating the inertia and damping characteristics of the synchronous generator. The virtual synchronous generator includes an active loop and a passive loop. The active loop is used to adjust the frequency and phase of the inverter, which is similar to the speed regulation function of the traditional synchronous generator. It enables the inverter to respond to the frequency changes of the power grid, helping to stabilize the frequency and phase of the system and keep it synchronized with the power grid. The passive loop is used to adjust the amplitude of the inverter, that is, the size of the output voltage, to ensure that the voltage output by the inverter is within a suitable range to maintain the stability of the grid voltage and support the adjustment of the power factor.

[0043] The inertia and damping of the synchronous generator are simulated by the virtual synchronous generator, so that the inverter operates similarly to the traditional synchronous generator in terms of operating characteristics and external characteristics. This can improve the response speed of the inverter to frequency and voltage changes, thereby enhancing the stability of the power system. When using it, it is necessary to set the operating parameters of the inverter, including the reference values ​​of active and reactive power and the reference value of the PCC terminal voltage.

[0044] In the present invention, an adaptive control strategy is adopted to control the inverter through a virtual synchronous generator, and the control parameters are adjusted in real time according to the dynamic changes of the system and external disturbances. This can improve the system's adaptability to factors such as load changes and power grid failures, thereby improving the stability and reliability of the system. The improved virtual synchronous machine control principle is based on a deep understanding of the dynamic characteristics and stability of the system. It monitors system state variables (such as voltage, frequency, current, etc.) and adjusts the control strategy according to predetermined control objectives (such as maintaining voltage and frequency stability). Compared with the traditional control of the inverter by a virtual synchronous generator with fixed control parameters, the adaptive control strategy, in which the moment of inertia J and the damping coefficient D cooperate with the adaptive VSG control, has better frequency fluctuation suppression performance, which can not only reduce the rate of change of frequency fluctuations, but also reduce frequency offset, and ultimately reduce frequency overshoot and improve frequency stability performance. It also shows that the virtual synchronous generator has strong control flexibility. Specifically:

[0045] 1) Reduce system oscillations: An appropriate damping coefficient D can help prevent excessive oscillations or instability in the system. It can adjust the damping of the VSG so that the system can return to a stable state more smoothly when the load changes or the grid fails.

[0046] 2) Enhanced inertia: Increasing the moment of inertia J will enhance the inertia of the VSG, making it more similar to a traditional synchronous generator. This means that the VSG will respond more slowly to external disturbances (such as load changes or grid faults) and the system stability will be higher.

[0047] 3) Improved frequency stability: Appropriate moment of inertia J can help maintain the frequency stability of the system because it can provide more inertia reserve to offset the frequency fluctuations caused by load changes.

[0048] The control system is used to: According to the real-time operating status of the power grid and the real-time external disturbance, the frequency, phase and amplitude of the inverter are adjusted in real time through the virtual synchronous generator.

[0049] The control system of the virtual synchronous generator monitors the state of the power grid and external disturbances in real time and dynamically adjusts the output according to this information to maintain the stability of the power system of the power grid. The control system adopts an adaptive control strategy to adjust the control parameters in real time according to the dynamic changes of the system and external disturbances to improve the system's adaptability to factors such as load changes and power grid failures.

[0050] Optionally, in the above technical solution, a camera module and a deep learning network algorithm module are also included;

[0051] The camera module is used to: collect images of the inverter mainboard and send them to the deep learning network algorithm module;

[0052] The camera module can be a single camera or a collection of multiple cameras. The camera module is installed above the inverter mainboard so that the camera module can collect images of the entire inverter mainboard. The camera in the camera module uses a high-resolution camera to ensure that the tiny components on the inverter mainboard can be clearly captured. The camera module is installed above the inverter mainboard through a bracket or a fixing device (a space reserved inside the inverter) to ensure that the camera module is firmly installed above the inverter mainboard.

[0053] The deep learning network algorithm module is used to: identify the image of the inverter mainboard and determine whether there are damaged components in the inverter mainboard.

[0054] The deep learning network algorithm module is integrated in an independent processor, which can be set on the inverter mainboard. The processor uses dedicated hardware devices such as GPU accelerators to improve processing speed and efficiency. The deep learning network algorithm module receives the image of the inverter mainboard sent by the camera module, and recognizes the image of the inverter mainboard to determine whether there are damaged components in the inverter mainboard.

[0055] Among them, the deep learning network algorithm module recognizes the image of the inverter motherboard through a pre-trained target detection algorithm. Specifically, the small target recognition algorithm based on YOLO is used to accurately recognize small targets through enhanced features, multi-scale feature extraction, attention mechanism and data enhancement, thereby improving the efficiency and accuracy of the monitoring system. Today, deep learning technology is an important branch in the field of artificial intelligence, and has made significant progress in target detection tasks in recent years. Traditional target detection methods usually require multi-stage processing processes, such as feature extraction, candidate region generation, classification and position regression, etc. These processes are usually performed independently, resulting in complex algorithms and large computational workloads. The emergence of deep learning target detection algorithms enables target detection tasks to be performed in an end-to-end manner, simplifying the process and improving accuracy. This device applies small target recognition to fault identification and processing of inverters. In the real-time damaged component monitoring system on the inverter motherboard circuit, since the components are usually small, it is necessary to adopt recognition technology for small targets. The Darknet-53 network structure used in the YOLO target detection algorithm is a deep learning model, which is part of the YOLO series of algorithms and is specifically designed for target detection tasks. The Darknet-53 network is named because it has 53 convolutional layers. This network structure is used as the backbone network (BackBone) in YOLO, which is responsible for extracting features of the input image. The design of the Darknet-53 network is unique compared to the deeper networks of the same period, such as ResNet-101 and ResNet-152. First, Darknet-53 does not use the maximum pooling layer (Maxpooling layer) for downsampling, but instead uses the convolution layer to achieve downsampling, which may be one of the reasons for its faster running speed. In addition, the number of convolution kernels and parameters of Darknet-53 is relatively small, which reduces the amount of calculation, which is also one of the reasons for its faster running speed.

[0056] like Figure 2 As shown, the location of the fault can be identified by the camera, and when the temperature sensor identifies the fault, the fire extinguishing device is activated to eliminate the fault. The two are in a parallel relationship.

[0057] Optionally, the above technical solution also includes a target detection and circuit breaker module, which is used to: when the deep learning network algorithm module identifies damaged components, implement circuit breaking measures on the circuit where the damaged components are located.

[0058] The target detection and circuit breaker module includes multiple mechanical switches. The target detection and circuit breaker module is located on the main board of the inverter and is integrated with a processor equipped with a deep learning network algorithm module. The target detection and circuit breaker modules are linked. When a problem is detected, the processor processes the information and gives an action command to the circuit breaker module.

[0059] Optionally, in the above technical solution, a temperature sensing device is also included; the temperature sensing device is used to collect the temperature of the mainboard of the inverter and send it to the control system.

[0060] Among them, the temperature sensing device is specifically a temperature sensor, which is connected to the control system through a cable. The temperature sensor monitors the temperature changes of the inverter mainboard in real time, and transmits the real-time collected temperature of the inverter mainboard to the control system through the cable.

[0061] Optionally, in the above technical solution, the control system is also used to: trigger a fire extinguishing mechanism when the temperature of the mainboard of the inverter exceeds a preset temperature threshold.

[0062] Among them, the preset temperature threshold can be set according to actual conditions.

[0063] Among them, triggering the fire extinguishing mechanism specifically refers to: triggering a fire extinguishing warning, or starting a fire extinguishing device to prevent fire accidents and ensure the safety of the inverter system and the surrounding environment.

[0064] At present, in the operation process of the inverter, in addition to the influence of power quality on the operating status, the status of the inverter body components also plays a decisive role. The components on the inverter mainboard are easily affected by factors such as the external environment and load fluctuations, resulting in damage and failure of the components. At present, the detection of damaged components on the inverter mainboard usually relies on manual inspection or regular maintenance, which has the following problems and limitations:

[0065] 1) Manual inspection is not timely: Since inverters are usually installed outdoors or at high altitudes, manual inspection requires a lot of manpower and time, and the timeliness of the inspection cannot be guaranteed.

[0066] 2) Reliance on regular maintenance: Currently, some inverter manufacturers provide detection systems that rely on regular maintenance, such as periodic system detection or alarm functions. However, this method may not be able to detect hidden damage or faults, resulting in problems being more serious when they are discovered.

[0067] 3) Lack of real-time monitoring: Current detection systems are usually based on discrete data collection and lack real-time monitoring and response capabilities. Once a failure occurs, it may cause power grid interruption or other losses.

[0068] In the present invention, a deep learning target detection algorithm is used in combination with a circuit breaker and a temperature sensing device. Real-time monitoring and rapid response, specifically, real-time monitoring of small damaged components on the mainboard, and taking circuit breaking measures immediately when damage is found, to avoid the expansion of component failures and ensure the stable operation of the inverter system. The temperature sensing device monitors the temperature changes of the inverter mainboard. Once an abnormal situation is found, the fire extinguishing device is immediately activated to prevent fire accidents and ensure the safety of the inverter system and the surrounding environment. Timely circuit breaking protection avoids the impact of damaged components on the entire inverter system, which is conducive to extending the service life of the inverter equipment and reducing the cost of maintenance and replacement. Through automated detection of damaged components and circuit breaking protection, the need for manual inspection is reduced, the operation and maintenance costs and manpower investment are reduced, and the operating efficiency of the inverter system is improved. The advanced deep learning target detection algorithm and intelligent circuit breaking protection mechanism are adopted to effectively reduce the failure rate of the inverter system, improve the reliability and stability of the system, and can play an important role in the operation management and safety assurance of inverter systems such as solar inverter systems, which is conducive to promoting the progress and application of solar power generation technology.

[0069] like Figure 3 As shown, a control method of a power grid inverter according to an embodiment of the present invention includes:

[0070] S1. Obtain the real-time operating status and external disturbance of the power grid where the inverter is located;

[0071] S2. According to the real-time operation status of the power grid and the real-time external disturbance, the frequency, phase and amplitude of the inverter are adjusted in real time through the virtual synchronous generator.

[0072] Optionally, in the above technical solution, it also includes:

[0073] S3, collecting an image of the inverter mainboard through a camera module;

[0074] S4. Identify the image of the inverter mainboard to determine whether there are damaged components in the inverter mainboard.

[0075] Optionally, in the above technical solution, it also includes:

[0076] S5. When a damaged component is identified, a circuit breaker measure is implemented on the circuit where the damaged component is located through the target detection and circuit breaker module.

[0077] Optionally, in the above technical solution, it also includes:

[0078] S6. Collect the temperature of the inverter mainboard through a temperature sensing device.

[0079] Optionally, in the above technical solution, it also includes:

[0080] S7. When the temperature of the inverter mainboard exceeds a preset temperature threshold, the fire extinguishing mechanism is triggered.

[0081] In the above embodiments, although the steps are numbered S1, S2, etc., these are only specific embodiments given by the present invention. Those skilled in the art may adjust the execution order of S1, S2, etc. according to actual conditions, which is also within the protection scope of the present invention. It can be understood that in some embodiments, some or all of the above embodiments may be included.

[0082] In the present invention, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0083] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0084] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A control system for a power grid inverter, characterized in that: Includes virtual synchronous generator and control system; The virtual synchronous generator is used to: control the frequency, phase and amplitude of the inverter in the power grid by simulating the synchronous generator; The control system is used to adjust the frequency, phase and amplitude of the inverter in real time through the virtual synchronous generator according to the real-time operating state of the power grid and the real-time external disturbance situation.

2. A control system for a power grid inverter according to claim 1, characterized in that: It also includes a camera module and a deep learning network algorithm module; The camera module is used to: collect an image of the inverter mainboard and send it to the deep learning network algorithm module; The deep learning network algorithm module is used to: identify the image of the inverter mainboard and determine whether there are damaged components in the inverter mainboard.

3. The control system of a power grid inverter according to claim 2, characterized in that: It also includes a target detection and circuit breaker module, which is used to: when the deep learning network algorithm module identifies damaged components, implement circuit breaking measures on the circuit where the damaged components are located.

4. The control system of a power grid inverter according to claim 2, characterized in that: It also includes a temperature sensing device; the temperature sensing device is used to collect the temperature of the mainboard of the inverter and send it to the control system.

5. A control system for a power grid inverter according to claim 4, characterized in that: The control system is also used to trigger a fire extinguishing mechanism when the temperature of the mainboard of the inverter exceeds a preset temperature threshold.

6. A control method for a power grid inverter, characterized in that: include: Obtain the real-time operating status and external disturbance conditions of the power grid where the inverter is located; According to the real-time operating state of the power grid and the real-time external disturbance situation, the frequency, phase and amplitude of the inverter are adjusted in real time through the virtual synchronous generator.

7. A control method for a power grid inverter according to claim 6, characterized in that: Also includes: Capturing an image of the inverter mainboard through a camera module; The image of the inverter mainboard is identified to determine whether there are damaged components in the inverter mainboard.

8. A control method for a power grid inverter according to claim 7, characterized in that: Also includes: When a damaged component is identified, a circuit breaker measure is implemented on the circuit where the damaged component is located through the target detection and circuit breaker module.

9. The control method of a power grid inverter according to claim 7, characterized in that: Also includes: The temperature of the mainboard of the inverter is collected by a temperature sensing device.

10. A control method for a power grid inverter according to claim 9, characterized in that: Also includes: When the temperature of the mainboard of the inverter exceeds a preset temperature threshold, a fire extinguishing mechanism is triggered.

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