Power grid coordination control system and method

Abstract

The invention discloses a power grid coordination control system and method, and belongs to the technical field of power grid coordination control, a selection signal generation module is matched with a first data selector, a plurality of parallel fault signals are selected in sequence and integrated into fault codes, unified output of the multiple fault signals is achieved, and the power grid coordination control efficiency is improved. According to the invention, a single port does not need to be adapted to each fault acquisition device, the data identification process is simplified, and meanwhile, the standby inversion logic can be automatically switched through the second data selector when the power coordination controller has a fault, so that the uninterrupted energy transmission between the main power grid and the micro-grid is ensured, and the reliability of the power coordination controller is improved. Power grid supply and demand balance and load power supply stability are guaranteed, and the problem that fault identification and overall control are too complex due to multiple system ports and complex wiring caused by lack of an effective unified integration path for fault collection of core equipment of an existing power grid is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power grid coordinated control, in particular to a power grid coordinated control system and method. BACKGROUND

[0002] With the rapid development of new energy power generation technology, microgrid as an important carrier of integrating new energy generation module, energy storage module and load module, its collaborative operation with the main grid is increasingly critical. To achieve efficient energy scheduling and supply-demand balance between the main grid and the microgrid, it is usually necessary to build a bidirectional energy transfer channel with the help of a power coordination controller and a bidirectional inverter module, adjust the energy surplus and shortage through the energy storage module, such as storing energy when there is a surplus of energy and releasing energy when there is a shortage, and rely on an energy monitoring module to monitor the remaining energy state of the energy storage module in real time. In addition, the main grid, microgrid, power coordination controller and bidirectional inverter module are the core components of the system, and the stability of their operation state directly determines the overall reliability of the grid. Therefore, fault detection and rapid disposal of the above components are important links to ensure the safe and efficient operation of the grid. However, there are still many problems to be solved in the current application of power grid coordinated control and fault detection technology, which restricts the further improvement of system performance.

[0003] Chinese patent, publication number: CN116031882A, publication date: April 28, 2023, discloses an island alternating current microgrid group hierarchical coordination control method and system, which divides the microgrid group into an upper layer network with microgrids as basic units and a lower layer network with distributed power sources as basic units; obtains the state of each distributed power source and constructs a lower layer network droop control model and an upper layer network droop control model based on a consistency protocol; coordinates control of the microgrid based on the lower layer network droop control model and the upper layer network droop control model; constructs a microgrid group hierarchical structure power coordination control model based on the coordination control result, and realizes hierarchical coordination control of the microgrid group based on the microgrid group hierarchical structure power coordination control model. However, when the core equipment of the power grid fails, it lacks backup control logic, which may completely interrupt the energy transfer between the main grid and the microgrid, affecting the supply-demand balance and load power supply stability of the power grid. SUMMARY

[0004] The present application is directed to the problem that the existing power grid core equipment fault collection lacks effective unified integration path, resulting in too many system ports and complex wiring, thus causing too complex fault identification and overall control. The present application provides a power grid coordinated control system and method, which realizes unified output of multiple fault signals by cooperating the selection signal generation module with the first data selector to sequentially select and integrate multiple parallel fault signals into fault codes, without adapting separate ports for each fault collection device, simplifying the data identification process. Meanwhile, through the second data selector, when the power coordination controller fails, it can automatically switch to the standby inverter logic, ensuring uninterrupted energy transfer between the main power grid and microgrid, and guaranteeing power supply balance and load power supply stability.

[0005] In a first aspect, the technical solution provided in the embodiments of the present application is a power grid coordinated control system, comprising a first data selector, a selection signal generation module, a power grid fault judgment module, a second data selector and a fault collection module. The fault collection module collects the operating state signals of the power coordination controller, the bidirectional inverter module, the main power grid and the microgrid respectively, and sends them to the corresponding ports of the first data selector respectively. The selection signal generation module sends ordered selection signals at preset time intervals. The first data selector collects the received operating state signals of the corresponding ports based on the selection signals, and generates fault codes based on the operating state signals. The power grid fault judgment module has a preset fault identification code table, matches the fault codes with the fault identification code table, and determines the power grid fault type based on the matching result. The second data selector selects the inverter logic of the bidirectional inverter module based on the operating state of the power coordination controller. The bidirectional inverter module controls the power supply relationship between the main power grid and the microgrid based on the inverter logic.

[0006] In this scheme, the first data selector integrates multiple operating state signals, only one set of core signal transmission link is needed to complete the ordered collection of multiple device signals, greatly reducing the number of ports. At the same time, the multiple operating state signals are converted into standardized fault codes, and the subsequent power grid fault judgment module does not need to develop differentiated signal analysis algorithms for different devices, but only needs a set of fault code and fault type matching logic to realize unified processing. Through the second data selector, a double control path is constructed. When the power coordination controller is normal, the control logic output by it is selected. When the controller fails, the standby control logic is automatically switched to, ensuring that the bidirectional inverter module can still normally adjust the power supply relationship between the main power grid and the microgrid, avoiding power supply imbalance caused by single device failure.

[0007] As preferred, the fault collection module comprises a first fault collection module, a second fault collection module, a third fault collection module and a fourth fault collection module; The first fault collection module collects a direct-current voltage signal and a communication signal of the power coordination controller; The second fault collection module collects a current signal and an output signal of the bidirectional inverter module; The third fault collection module collects an alternating-current voltage signal and a grid frequency of the main grid; The fourth fault collection module collects a power generation output signal of the microgrid.

[0008] In the scheme, due to the essential differences between the fault causes and characteristic signals of different core devices of the grid, the classified collection can capture the key signals that can best reflect the fault state of the device. The power coordination controller is the control center, and its faults are mostly caused by abnormal hardware power supply or communication link interruption. The bidirectional inverter module is the energy conversion core, and its faults are mostly reflected in abnormal power loop or output waveform distortion. The fault core of the main grid is abnormal power supply quality, so only voltage and frequency signals need to be collected. The microgrid contains new energy power generation, and its faults are mostly related to power generation and load imbalance, so different operating state signals are collected for different modules to accurately determine whether the core device has failed.

[0009] As preferred, if the deviation degree of the direct-current voltage signal exceeds the voltage deviation threshold and / or the communication signal does not receive / send valid data frames for t consecutive time points, the first fault collection module outputs high level, otherwise outputs low level; If the peak value of the current signal exceeds the rated current deviation threshold and lasts for i time points and / or the distortion degree of the output signal exceeds the set threshold and lasts for n periods, the second fault collection module outputs high level, otherwise outputs low level; If the alternating-current voltage signal exceeds the rated voltage deviation threshold and / or the grid frequency is outside the preset frequency range and lasts for j time points, the third fault collection module outputs high level, otherwise outputs low level; If the power generation output signal exceeds the energy storage rated power deviation threshold, the fourth fault collection module outputs high level, otherwise outputs low level.

[0010] In the scheme, a standardized judgment system is constructed by the signals collected by the fault collection module, the judgment standard of whether the core equipment of the power grid appears a fault is quantified, and multi-condition superposition judgment is adopted to avoid misjudgment caused by single signal fluctuation and ensure the judgment accuracy; the judgment result is output in high / low level, so that the subsequent first data selector does not need to adapt to different types of original signals, and only needs to receive the level signal through a general digital signal interface, which greatly simplifies the hardware adaptation difficulty; at the same time, when the power grid fault judgment module generates a fault code, it does not need to perform complex analog-digital conversion or parameter calculation on the original signal, but only needs to directly read the level state, which significantly reduces the software development workload.

[0011] As preferred, the coordinated control system further comprises an energy storage module and an electric energy monitoring module, the electric energy monitoring module monitors the residual electric energy of the energy storage module in real time, and outputs a low-level signal if the residual electric energy of the energy storage module is greater than or equal to an energy storage threshold value; and outputs a high-level signal if the residual electric energy of the energy storage module is less than the energy storage threshold value.

[0012] In the scheme, since the energy storage module serves as an energy buffer between the main power grid and the micro-grid, the residual electric energy thereof directly determines the rationality of the power grid energy scheduling strategy, if the residual electric energy of the energy storage module is sufficient, the micro-grid can preferentially store the surplus electric energy generated by the new energy power generation, thereby avoiding power grid fluctuation caused by feeding energy to the main power grid; if the residual electric energy of the energy storage module is insufficient, the energy needs to be supplemented from the main power grid to prevent the energy storage from being excessively discharged and damaging the battery; the electric energy monitoring module directly feeds back the energy storage state in high / low level through real-time monitoring, so that the system can quickly obtain core data without complex calculation, compared with the traditional way of indirectly calculating the residual electric energy by collecting current or voltage signals, the energy scheduling decision delay can be greatly reduced, and blind charging and discharging caused by misjudgment of the energy storage state can be avoided.

[0013] As preferred, the first input port of the second data selector is connected with the output end of the power coordinated controller, the second input port is connected with the output end of the electric energy monitoring module, and the third input port is connected with the output end of the first fault collection module; When the power coordinated controller appears a fault, the first fault collection module sends a high-level signal to the positive power supply pin of the second data selector, after the second data selector receives the high-level signal, if the electric energy monitoring module outputs a high-level, the bidirectional inverter module is controlled to make the main power grid transmit electric energy to the micro-grid, and if the electric energy monitoring module outputs a low-level, the bidirectional inverter module is controlled to make the micro-grid transmit electric energy to the main power grid.

[0014] In the scheme, the core state of the power coordination controller is collected in real time by the first fault collection module. When the controller fails, the first fault collection module immediately sends a high level to the positive power supply pin of the second data selector, without manual intervention or additional logic judgment, to trigger the standby control path switching, avoiding the delay problem of the traditional system that needs to analyze the data by the central processor and then issue the switching instruction, thereby ensuring that the bidirectional inverter module can still obtain effective control signals at the moment of the power coordination controller failure, and completely solving the problem of energy transmission interruption between the main grid and the microgrid caused by the single-point failure of the controller. The standby control logic adopted does not use a simple fixed mode, but uses the output level of the electric energy monitoring module as the core basis to ensure that even in the scene without precise control of the controller, the grid can still maintain basic energy balance, rather than falling into the imbalance between supply and demand caused by blind power transmission.

[0015] Preferably, the first input port of the power coordination controller is connected with the main grid, and the second input port is connected with the microgrid. When the power coordination controller is running normally, the electric energy output of the main grid and the microgrid is detected. If the electric energy output of the main grid is greater than or equal to the rated output of the main grid and greater than the electric energy output of the microgrid, a high level signal is sent to the second data selector to control the bidirectional inverter module to make the main grid transmit electric energy to the microgrid. If the electric energy output of the microgrid is greater than or equal to the rated output of the microgrid and greater than the electric energy output of the main grid, a low level signal is sent to the second data selector to control the bidirectional inverter module to make the microgrid transmit electric energy to the main grid.

[0016] In the scheme, since the microgrid usually integrates photovoltaic, wind power and other new energy power generation modules, its electric energy output is essentially the result of new energy power generation. When the microgrid output is greater than or equal to the rated output and greater than the main grid output, the power coordination controller controls it to feed energy to the main grid, which is equivalent to guiding the surplus new energy of the microgrid that cannot be consumed into the main grid, avoiding the waste of new energy due to the limited local load and insufficient energy storage capacity of the microgrid. When the main grid is in the valley of electricity consumption, its electric energy output is usually greater than or equal to the rated output and greater than the microgrid output. At this time, the controller controls the main grid to transmit electricity to the microgrid, which can store the surplus electric energy of the main grid to the microgrid energy storage module or supply it to the microgrid load, realizing the peak-shaving utilization of the main grid electric energy. The complementarity and energy coordination between the two realize the mode of "valley main grid energy supplement and peak microgrid energy feeding", which not only reduces the overall operation cost of the main grid, but also reduces carbon emissions and improves energy utilization efficiency.

[0017] Preferably, the first data selector includes four input ports, each of which is connected with the output end of the first, second, third and fourth fault collection modules. The selection signal comprises sequentially arranged sub-signals, four sub-signals as a period of the selection signal, each sub-signal having a different value and corresponding to an input port of the first data selector; When the first data selector receives a sub-signal, the operating state signal received by the corresponding input port is selected based on the order of the sub-signal in the selection signal, and a four-bit binary fault code is generated based on the level and order of the operating state signal.

[0018] In this scheme, the periodic sub-signals of the selection signal control the first data selector to realize time-sharing acquisition, avoiding signal distortion caused by level superposition and electromagnetic interference when the four types of signals are transmitted in parallel, thereby ensuring the accuracy of signal acquisition and providing an accurate data basis for subsequent fault location; the sub-signals of the selection signal are arranged in a fixed order, and each sub-signal is bound to a specific input port, so that the data selector does not need complex address resolution, but only needs to determine the port to be acquired by the order of the sub-signal in the period, and can generate a standard binary fault code, according to the order, only needs to determine which bits in the fault code are in high level to quickly determine which device has failed, without analog-to-digital conversion or complex algorithms, and without analyzing the original signal, significantly improving the positioning and identification efficiency of the fault.

[0019] Preferably, the power grid coordinated control system further comprises a wireless communication module and a micro-grid management platform; The wireless communication module is configured to realize communication between the first data selector and the micro-grid management platform; and the micro-grid management platform is configured to check the fault code output by the first data selector.

[0020] In this scheme, the micro-grid management platform checks the fault code output by the first data selector, including CRC (Cyclic Redundancy Check), parity check, data length check, etc., which can effectively identify the distortion of the fault code caused by electromagnetic interference and signal attenuation in the wireless transmission process, and if the unverified fault code is directly transmitted to the power grid fault judgment system, it will cause the power grid coordinated controller fault to be missed and the maintenance to be delayed; and the checking mechanism can compare the check value of the fault code with the received check information, if they are inconsistent, it is determined that the data is wrong, the first data selector is requested to resend, and the accuracy of the fault code entering the fault judgment system is ensured, avoiding the fault misjudgment caused by data error from the source.

[0021] Preferably, the power grid coordinated control system further comprises a load module and a new energy power generation module; The load module is configured to process the electric energy generated by the micro-grid; and the new energy power generation module is configured to provide new energy electric energy for the micro-grid.

[0022] In the scheme, the new energy power generation module takes renewable energy as input, and can continuously output zero-carbon green power for the micro-grid, and the load module can preferentially consume the local power generated by the new energy power generation module, avoiding the loss caused by long-distance transmission of power, and providing convenience for the mutual coordination of the main grid and the micro-grid in the subsequent power grid; The mode of the new energy power generation module supplying power for the micro-grid and the load module consuming locally can reduce the power consumption application of the micro-grid to the main grid, especially during the peak period of the main grid power consumption, the micro-grid can meet its own load demand through new energy power, and even feed energy to the main grid when the new energy output is sufficient, to share the power supply pressure of the main grid, thereby optimizing the overall load curve of the main grid, reducing the frequent start-stop problem of the unit caused by the large load peak-valley difference of the main grid, and improving the operation stability of the main grid.

[0023] In a second aspect, a technical scheme provided in an embodiment of the present application is a power grid coordination control method, comprising the following steps: S1, collecting the running state signals of the core devices in the power grid in real time, and sending them to the corresponding ports of the first data selector; S2, generating a selection signal in which the sub-signals are arranged in order based on a preset time interval; collecting the running state signals received by the corresponding ports of the first data selector based on the ordering of the sub-signals in the selection signal, and generating a fault code based on the running state signals; S3, matching the fault code with the fault identification code table based on the preset fault identification code table, and determining the fault device in the power grid based on the matching result; S4, if there is a fault device in the power grid and the power coordination controller is normal, the second data selector selects the first inversion logic of the bidirectional inversion module; if the power coordination controller fails, the second data selector selects the second inversion logic of the bidirectional inversion module; and coordinating the power supply relationship between the main grid and the micro-grid based on the first / second inversion logic.

[0024] In the scheme, on the basis of realizing rapid judgment of multiple device faults and ensuring continuity of energy transmission, the operation reliability and convenience of the power grid coordination control system based on new energy storage are further improved, effectively supporting efficient cooperation between the main grid and the micro-grid, and meeting the operation requirements of the new energy power grid.

[0025] The present application has the following advantages: by cooperating the selection signal generation module with the first data selector, the present application selects and integrates multiple parallel fault signals into a fault code one by one, realizes the unified output of multiple fault signals, does not need to adapt a separate port for each fault collection device, simplifies the data identification process, and through the second data selector, when the power coordination controller fails, it can automatically switch to the backup inversion logic, ensuring uninterrupted energy transmission between the main grid and the micro-grid, and ensuring the balance between supply and demand of the power grid and the stability of load power supply.

[0026] The above description of the invention is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0027] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings. The drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings.

[0028] Figure 1 This is a schematic diagram of a power grid coordinated control system according to the present invention; Figure 2 This is a flowchart of a power grid coordinated control method according to the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only one preferred embodiment of this invention and are only used to explain this invention. They do not limit the scope of protection of this invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0030] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the operations (or steps) as sequential processes, many of the operations (or steps) can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but it may also have additional steps not included in the figures; the process may correspond to a method, function, procedure, subroutine, subroutine, etc.

[0031] Example 1: As Figure 1 As shown, in order to solve the problem that the lack of an effective unified integration path for fault acquisition of core equipment in the existing power grid leads to the problem that the system has many ports and complex wiring, resulting in overly complex fault identification and overall control, this embodiment provides a power grid coordinated control system, including a first data selector, a selection signal generation module, a power grid fault judgment module, a second data selector, a fault acquisition module, a wireless communication module, a microgrid management platform, a load module, and a new energy power generation module. The fault collection module collects the operation state signals of the power coordination controller, the bidirectional inversion module, the main power grid and the micro-grid respectively, and sends them to the corresponding ports of the first data selector respectively. The selection signal generation module sends the ordered selection signals at preset time intervals. The first data selector collects the received operation state signals of the corresponding ports based on the selection signals, and generates fault codes based on the operation state signals. The power grid fault judgment module stores a preset fault identification code table, matches the fault codes with the fault identification code table, and determines the power grid fault type based on the matching result. The second data selector selects the inversion logic of the bidirectional inversion module based on the operation state of the power coordination controller. The bidirectional inversion module controls the power supply relationship between the main power grid and the micro-grid based on the inversion logic. The wireless communication module is used to realize communication between the first data selector and the micro-grid management platform; the micro-grid management platform is used to check the fault codes output by the first data selector. The load module is used to process the electrical energy generated by the micro-grid; the new energy power generation module is used to provide new energy electrical energy for the micro-grid.

[0032] In this embodiment, the fault collection module includes a first fault collection module, a second fault collection module, a third fault collection module and a fourth fault collection module. The first fault collection module collects the DC voltage signal and the communication signal of the power coordination controller. The second fault collection module collects the current signal and the output signal of the bidirectional inversion module. The third fault collection module collects the AC voltage signal and the power grid frequency of the main power grid. The fourth fault collection module collects the power generation output signal of the micro-grid.

[0033] In this embodiment, due to the essential differences in the fault causes and characteristic signals of different core devices of the power grid, the classified collection can capture the key signals that can best reflect the fault state of the device, wherein the power coordination controller as the control center, its fault is mostly caused by hardware power supply abnormality or communication link interruption; the bidirectional inversion module as the energy conversion core, the fault is mostly reflected in the power loop abnormality or output waveform distortion; the fault core of the main power grid is power supply quality abnormality, so only the voltage and frequency signals need to be collected; the micro-grid contains new energy power generation, and the fault is mostly related to the imbalance between power generation and load balance, so different operation state signals are collected for different modules, so as to accurately determine whether the core device has failed.

[0034] In the embodiment, if the deviation degree of the direct current voltage signal exceeds the voltage deviation threshold and / or the communication signal does not receive / send valid data frame for t continuous time, the first fault collection module outputs high level, otherwise, outputs low level. If the peak value of the current signal exceeds the rated current deviation threshold and lasts for i time and / or the output signal distortion exceeds the set threshold and lasts for n periods, the second fault collection module outputs high level, otherwise, outputs low level. If the alternating current voltage signal exceeds the rated voltage deviation threshold and / or the power grid frequency is outside the preset frequency range and lasts for j time, the third fault collection module outputs high level, otherwise, outputs low level. If the power generation output signal exceeds the energy storage rated power deviation threshold, the fourth fault collection module outputs high level, otherwise, outputs low level.

[0035] The embodiment constructs a standardized judgment system for the signals of the fault collection module, quantifies the judgment standard of whether the core equipment of the power grid appears fault, adopts multi-condition superposition judgment, avoids misjudgment of single signal fluctuation, and ensures the judgment accuracy; by outputting the judgment result as high / low level, the subsequent first data selector does not need to adapt different types of original signals, only needs to receive the level signal through the general digital signal interface, greatly simplifies the hardware adaptation difficulty; at the same time, when the power grid fault judgment module generates the fault code, it does not need to perform complex analog-digital conversion or parameter calculation on the original signal, only needs to directly read the level state, significantly reduces the software development workload.

[0036] In the embodiment, the coordinated control system further includes an energy storage module and an electric energy monitoring module, the electric energy monitoring module monitors the residual electric energy of the energy storage module in real time, if the residual electric energy of the energy storage module is greater than or equal to the energy storage threshold, the electric energy monitoring module outputs a low level signal; If the residual electric energy of the energy storage module is less than the energy storage threshold, the electric energy monitoring module outputs a high level signal.

[0037] In the embodiment, the energy storage module serves as an energy buffer between the main power grid and the micro-grid, and its residual electric energy directly determines the rationality of the power grid energy scheduling strategy, if the residual electric energy of the energy storage is sufficient, the micro-grid can preferentially store the new energy power generation surplus electric energy, avoiding the power grid fluctuation caused by feeding energy to the main power grid; if the residual electric energy of the energy storage is insufficient, the electric energy needs to be supplemented from the main power grid to prevent the energy storage from over-discharging and damaging the battery; the electric energy monitoring module directly feeds back the energy storage state through real-time monitoring and high / low level intuitive feedback, so that the system can quickly obtain the core data without complex calculation, compared with the traditional way of indirectly calculating the residual electric energy by collecting current or voltage signals, the energy scheduling decision delay can be greatly reduced, and blind charging and discharging caused by misjudgment of the energy storage state are avoided.

[0038] In this embodiment, the first input port of the second data selector is connected with the output of the power coordination controller, the second input port is connected with the output of the power monitoring module, and the third input port is connected with the output of the first fault acquisition module. When the power coordination controller fails, the first fault acquisition module sends a high-level signal to the positive power supply pin of the second data selector. After receiving the high-level signal, if the power monitoring module outputs a high level, the second data selector controls the bidirectional inverter module to make the main power grid transmit power to the micro-grid; if the power monitoring module outputs a low level, the second data selector controls the bidirectional inverter module to make the micro-grid transmit power to the main power grid.

[0039] Specifically, the second data selector can intelligently realize the selection output of signals: when the third input port is low (i.e., the power coordination controller is not faulty), the output end will automatically select the signal from the first input port (from the power coordination controller) for output; when the third input port is high (i.e., the power coordination controller is faulty), the output end will quickly switch to select the signal from the second input port (from the power monitoring module) for output; at the same time, the output end of the second data selector will stably send the selected signal to the bidirectional inverter module. Through the automatic switching mechanism, the problem of interruption of energy transmission between the main power grid and the micro-grid caused by single failure of the power coordination controller is effectively avoided, and the continuity of energy transmission is ensured when the controller fails, which significantly improves the fault tolerance and operation stability of the system.

[0040] The power monitoring module accurately detects whether the remaining power of the energy storage module is lower than a set threshold value such as 50% in real time; if the remaining power of the energy storage module is lower than the threshold value, the power monitoring module immediately sends a high level to the second data selector; if the remaining power of the energy storage module is higher than the threshold value, the power monitoring module continuously sends a low level to the second data selector. Through dynamic monitoring of the remaining power of the energy storage module, the system can real-time master the reserve condition of the energy storage resource, provide key power data support for subsequent operation mode switching of the bidirectional inverter module, ensure that the energy transmission direction matches the state of energy storage and power grid demand, and avoid excessive discharge of energy storage or waste of power.

[0041] The first fault acquisition module of the embodiment acquires the core state of the power coordination controller in real time. When the controller fails, the first fault acquisition module immediately sends a high level to the positive power supply pin of the second data selector, without manual intervention or additional logic judgment, to trigger the standby control path switching, avoiding the delay problem of the traditional system that needs to analyze the data by the central processor and then issue the switching instruction, thereby ensuring that the bidirectional inverter module can still obtain effective control signals at the moment of the power coordination controller failure, and completely solving the problem that the controller single-point failure causes the energy transmission interruption between the main grid and the microgrid. The standby control logic adopted does not use a simple fixed mode, but uses the output level of the electric energy monitoring module as the core basis to ensure that even in the scene without precise controller regulation, the grid can still maintain basic energy balance, rather than falling into the imbalance between supply and demand caused by blind power transmission.

[0042] In the embodiment, the first input port of the power coordination controller is connected with the main grid, and the second input port is connected with the microgrid. When the power coordination controller is normally running, the electric energy output of the main grid and the microgrid is detected. If the electric energy output of the main grid is greater than or equal to the rated output of the main grid and greater than the electric energy output of the microgrid, a high level signal is sent to the second data selector to control the bidirectional inverter module to make the main grid transmit electric energy to the microgrid. If the electric energy output of the microgrid is greater than or equal to the rated output of the microgrid and greater than the electric energy output of the main grid, a low level signal is sent to the second data selector to control the bidirectional inverter module to make the microgrid transmit electric energy to the main grid.

[0043] Specifically, the power coordination controller comprehensively acquires the grid operation data of the main grid and the microgrid, including key parameters such as voltage and current; at the same time, the power coordination controller also sends signals to the second data selector to effectively control the operation mode of the bidirectional inverter module. The controller acquires real-time operation data of the grid to ensure that a reasonable energy coordination strategy can be made based on the actual working conditions of the main grid and the microgrid, so that the operation mode of the bidirectional inverter module is accurately matched with the supply and demand state of the grid, and the rationality and efficiency of energy transmission between the main grid and the microgrid are guaranteed. The bidirectional inverter module realizes the bidirectional conversion of electric energy between the main grid and the microgrid; at the same time, the bidirectional inverter module timely receives the signals sent by the second data selector; when the signal received by the bidirectional inverter module is high level, it accurately controls the main grid to transmit electric energy to the microgrid; when the signal received by the bidirectional inverter module is low level, it stably controls the microgrid to transmit electric energy to the main grid. The bidirectional conversion function of the module guarantees the bidirectional smoothness of energy transmission between the main grid and the microgrid, which can supplement the electric energy of the microgrid when the main grid electric energy is sufficient, and can feedback the excess electric energy of the microgrid (such as the output of the new energy generation module) to the main grid, realizing the optimal allocation and efficient utilization of energy between the grids.

[0044] The embodiment is because the micro-grid usually integrates photovoltaic, wind power and other new energy power generation modules, and the power output is essentially the conversion result of new energy power generation. When the micro-grid output is greater than or equal to the rated output and greater than the main grid output, the power coordination controller controls the micro-grid to feed energy to the main grid, which is equivalent to guiding the surplus new energy of the micro-grid that cannot be absorbed into the main grid, avoiding the waste of new energy due to the limited local load and insufficient energy storage capacity of the micro-grid. When the main grid is in the power valley, its power output is usually greater than or equal to the rated output and greater than the micro-grid output. At this time, the controller controls the main grid to supply power to the micro-grid, which can store the surplus power of the main grid in the micro-grid energy storage module or supply it to the micro-grid load, realizes the peak-shaving utilization of the main grid power, and the complementation and energy coordination between the two realize the mode of "valley main grid power compensation and peak micro-grid power feeding". In the case of reducing the overall operation cost of the main grid, carbon emissions can also be reduced and energy utilization efficiency can be improved.

[0045] In the embodiment, the first data selector includes four input ports, each of which is connected to the output end of the first fault acquisition module, the second fault acquisition module, the third fault acquisition module and the fourth fault acquisition module respectively. The selection signal includes sequentially arranged sub-signals, and four sub-signals are taken as a period of the selection signal, each sub-signal has a different value and corresponds to an input port of the first data selector. When the first data selector receives a sub-signal, the running state signal received by the corresponding input port is selected based on the order of the sub-signal in the selection signal, and a four-bit binary fault code is generated based on the level and order of the running state signal.

[0046] The embodiment realizes time-sharing acquisition by the periodic sub-signals of the selection signal to control the first data selector, avoids signal distortion caused by level superposition and electromagnetic interference when the four types of signals are transmitted in parallel, thereby ensuring the accuracy of signal acquisition and providing an accurate data basis for subsequent fault positioning. Through the fixed order arrangement of the sub-signals of the selection signal and the binding of each sub-signal to a specific input port, the data selector does not need complex address resolution, but only needs to determine the port to be collected by the order of the sub-signal in the period, and can generate a standard binary fault code therefrom. According to the order, it can quickly determine which device has a fault by determining which bits in the fault code are at a high level, without analog-digital conversion or complex algorithms, and without analyzing the original signal, thereby significantly improving the positioning and identification efficiency of the fault.

[0047] Specifically, the embodiment is further described through a complete identification process: The selection signal generation module continuously and stably sends a series of ordered selection signals at intervals of approximately 30 seconds. These selection signals are 00, 01, 10, and 11. By regularly outputting these selection signals, this module provides a precise control basis for the first data selector to systematically filter fault signals, ensuring the regularity and controllability of the fault signal selection process and preventing chaotic fault signal acquisition due to disordered selection signals.

[0048] The first data selector, based on a series of selection signals output by the selection signal generation module, efficiently selects fault signals from ports A, B, C, and D sequentially for output. Simultaneously, it accurately generates a four-bit binary fault code, which is then sent to the wireless communication module. The wireless communication module then reliably transmits the fault code to the microgrid management platform, which subsequently forwards it to the grid fault diagnosis module. By orderly selecting and encoding multiple parallel fault signals, the complex system port adaptation issues caused by parallel transmission of multiple fault signals are avoided. This simplifies the signal transmission path and the system's fault signal reception logic, making fault signal transmission more efficient and easier to identify.

[0049] The power grid fault diagnosis module accurately determines whether faults have occurred in the power coordination controller, bidirectional inverter module, main grid, and microgrid based on a received series of fault signals. Simultaneously, the module pre-stores a fault identification code table matching the series of fault signals. This table consists of a four-bit binary identification code and its corresponding fault type, as shown in Table 1. The module then compares each received fault code with the codes in its table, identifying the fault type corresponding to the matching code to determine the power grid fault. This allows maintenance personnel to quickly locate specific faulty equipment and fault types without having to check the fault status of each device individually, significantly improving fault diagnosis efficiency in multi-device fault scenarios and saving valuable time in fault handling.

[0050] Table 1. Fault Identification Code Table Four-bit binary identification code Corresponding faulty device Fault type description 0000 None None of the power coordination controller, bidirectional inverter module, main grid, microgrid is faulty 0001 Microgrid Only the microgrid is faulty, and the rest of the devices are operating normally 0010 Main grid Only the main grid is faulty, and the rest of the devices are operating normally 0011 Main grid, microgrid Both the main grid and the microgrid are faulty, and the rest of the devices are operating normally 0100 Bidirectional inverter module Only the bidirectional inverter module is faulty, and the rest of the devices are operating normally 0101 Bidirectional inverter module, microgrid Both the bidirectional inverter module and the microgrid are faulty, and the rest of the devices are operating normally 0110 Bidirectional inverter module, main grid Both the bidirectional inverter module and the main grid are faulty, and the rest of the devices are operating normally 0111 Bidirectional inverter module, main grid, microgrid Both the bidirectional inverter module, main grid, and microgrid are faulty, and the power coordination controller is operating normally 1000 Power coordination controller Only the power coordination controller is faulty, and the rest of the devices are operating normally 1001 Power coordination controller, microgrid Both the power coordination controller and the microgrid are faulty, and the rest of the devices are operating normally 1010 Power coordination controller, main grid Both the power coordination controller and the main grid are faulty, and the rest of the devices are operating normally 1011 Power coordination controller, main grid, microgrid Both the power coordination controller, main grid, and microgrid are faulty, and the bidirectional inverter module is operating normally 1100 Power coordination controller, bidirectional inverter module Both the power coordination controller and the bidirectional inverter module are faulty, and the rest of the devices are operating normally 1101 Power coordination controller, bidirectional inverter module, microgrid Both the power coordination controller, bidirectional inverter module, and microgrid are faulty, and the main grid is operating normally 1110 Power coordination controller, bidirectional inverter module, main grid Both the power coordination controller, bidirectional inverter module, and main grid are faulty, and the microgrid is operating normally 1111 Power coordination controller, bidirectional inverter module, main grid, microgrid Both the power coordination controller, bidirectional inverter module, main grid, and microgrid are faulty The table above shows all the possible faults of various core components in the power grid and their corresponding fault codes.

[0051] Example 2: As Figure 2 As shown, this embodiment also provides a power grid coordinated control method, including the following steps: S1: Real-time acquisition of operating status signals of core equipment in the power grid and transmission to the corresponding port of the first data selector; S2: generating a selection signal in which the sub-signals are arranged in order based on a preset time interval; collecting the operation state signals received by the corresponding ports of the first data selector based on the order of the sub-signals in the selection signal, and generating a fault code based on the operation state signals; S3: matching the fault code with a preset fault identification code table, and determining the fault equipment in the power grid based on the matching result; S4: if there is a fault equipment in the power grid and the power coordination controller is normal, the second data selector selects the first inverter logic of the bidirectional inverter module; if the power coordination controller fails, the second data selector selects the second inverter logic of the bidirectional inverter module; and the power supply relationship between the main power grid and the micro-grid is coordinated based on the first / second inverter logic.

[0052] On the basis of realizing fast judgment of multiple equipment faults and guaranteeing continuity of energy transmission, the operation reliability and convenience of the power grid coordination control system based on new energy storage are further improved, efficient cooperation of the main power grid and the micro-grid is effectively supported, and the operation requirements of the new energy power grid are met.

[0053] From the above embodiments, at least the following substantial effects are obtained: (1) The first data selector is used for integrating multiple operation state signals, so that the ordered collection of multiple equipment signals can be completed by only one set of core signal transmission link, the number of ports is greatly reduced, and the multiple operation state signals are converted into standardized fault codes, so that the subsequent power grid fault judgment module does not need to develop differentiated signal analysis algorithms for different equipment, and only one set of matching logic of fault codes and fault types is needed to realize unified processing; (2) The second data selector constructs a double control path, when the power coordination controller is normal, the control logic output by the power coordination controller is selected, when the controller fails, the standby control logic is automatically switched to, so that the bidirectional inverter module can still normally adjust the power supply relationship between the main power grid and the micro-grid, and the imbalance between supply and demand of the power grid caused by single equipment failure is avoided; (3) The power grid fault judgment module compares the received fault codes with the preset fault code identification table, so that the fault conditions of the main power grid, the micro-grid, the power coordination controller and the bidirectional inverter module can be quickly determined, and the problem that it is difficult to quickly determine the cause when multiple equipment fails is effectively solved.

[0054] The specific embodiments described above are the preferred embodiments of the power grid coordination control system and method of the application, and do not limit the specific implementation range of the application, the range of the application includes but is not limited to the specific embodiments, and equivalent changes made according to the shape and structure of the application are within the protection scope of the application.

Claims

1. A power grid coordination control system, wherein the power grid includes a main power grid, a microgrid, a power coordination controller, and a bidirectional inverter module, characterized in that: It includes a first data selector, a selection signal generation module, a power grid fault judgment module, a second data selector, and a fault acquisition module; The fault acquisition module collects the operating status signals of the power coordination controller, the bidirectional inverter module, the main power grid and the microgrid respectively, and sends them to the corresponding ports of the first data selector respectively; The selection signal generation module sends ordered selection signals at preset time intervals; The first data selector acquires the received operating status signal of the corresponding port based on the selection signal, and generates a fault code based on the operating status signal; The power grid fault judgment module stores a preset fault identification code table, matches the fault code with the fault identification code table, and determines the power grid fault type based on the matching result; The second data selector selects the inverter logic of the bidirectional inverter module based on the operating status of the power coordination controller; The bidirectional inverter module controls the power supply relationship between the main power grid and the microgrid based on inverter logic.

2. The power grid coordinated control system according to claim 1, characterized in that: The fault acquisition module includes a first fault acquisition module, a second fault acquisition module, a third fault acquisition module, and a fourth fault acquisition module; The first fault acquisition module acquires the DC voltage signal and communication signal of the power coordination controller; The second fault acquisition module acquires the current signal and output signal of the bidirectional inverter module; The third fault acquisition module acquires the AC voltage signal and grid frequency of the main power grid; The fourth fault acquisition module acquires the power output signal of the microgrid.

3. A power grid coordinated control system according to claim 2, characterized in that: If the deviation of the DC voltage signal exceeds the voltage deviation threshold and / or the communication signal fails to receive / send valid data frames for t consecutive time periods, the first fault acquisition module outputs a high level; otherwise, it outputs a low level. If the peak value of the current signal exceeds the rated current deviation threshold and lasts for i time periods and / or the distortion of the output signal exceeds the set threshold and lasts for n cycles, then the second fault acquisition module outputs a high level; otherwise, it outputs a low level. If the AC voltage signal exceeds the rated voltage deviation threshold and / or the power grid frequency is outside the preset frequency range and lasts for j moments, the third fault acquisition module outputs a high level; otherwise, it outputs a low level. If the power generation output signal exceeds the energy storage rated power deviation threshold, the fourth fault acquisition module outputs a high level; otherwise, it outputs a low level.

4. A power grid coordinated control system according to claim 3, characterized in that: The coordinated control system also includes an energy storage module and an energy monitoring module. The energy monitoring module monitors the remaining energy of the energy storage module in real time. If the remaining energy of the energy storage module is greater than or equal to the energy storage threshold, the energy monitoring module outputs a low-level signal. If the remaining energy of the energy storage module is less than the energy storage threshold, the energy monitoring module outputs a high-level signal.

5. A power grid coordinated control system according to claim 4, characterized in that: The first input port of the second data selector is connected to the output of the power coordination controller, the second input port is connected to the output of the power monitoring module, and the third input port is connected to the output of the first fault acquisition module. When the power coordination controller malfunctions, the first fault acquisition module sends a high-level signal to the positive power supply pin of the second data selector. After receiving the high-level signal, if the power monitoring module outputs a high level, the second data selector controls the bidirectional inverter module to supply power from the main grid to the microgrid. If the power monitoring module outputs a low level, the bidirectional inverter module controls the microgrid to supply power from the main grid to the main grid.

6. A power grid coordinated control system according to claim 5, characterized in that: The first input port of the power coordination controller is connected to the main power grid, and the second input port is connected to the microgrid. When the power coordination controller is operating normally, it detects the power output of the main grid and the microgrid. If the power output of the main grid is greater than or equal to the rated output of the main grid and greater than the power output of the microgrid, it sends a high-level signal to the second data selector to control the bidirectional inverter module to send power from the main grid to the microgrid. If the power output of the microgrid is greater than or equal to the rated power output of the microgrid and greater than the power output of the main grid, a low-level signal is sent to the second data selector to control the bidirectional inverter module to send power from the microgrid to the main grid.

7. A power grid coordinated control system according to claim 2, characterized in that: The first data selector includes four input ports, each of which is connected to the output of the first fault acquisition module, the second fault acquisition module, the third fault acquisition module, and the fourth fault acquisition module, respectively. The selection signal includes sub-signals arranged in sequence. The four sub-signals are used as one cycle of the selection signal. Each sub-signal has a different value and corresponds to an input port of the first data selector. When the first data selector receives a sub-signal, it selects the corresponding input port to receive the operating status signal based on the order of the sub-signal in the selection signal, and generates a four-bit binary fault code based on the level and order of the operating status signal.

8. A power grid coordinated control system according to claim 1, characterized in that: The power grid coordination and control system also includes a wireless communication module and a microgrid management platform; The wireless communication module is used to enable communication between the first data selector and the microgrid management platform; the microgrid management platform is used to verify the fault codes output by the first data selector.

9. A power grid coordinated control system according to claim 1, characterized in that: The power grid coordination and control system also includes a load module and a new energy power generation module; The load module is used to process the electrical energy generated by the microgrid; the new energy power generation module is used to provide new energy to the microgrid.

10. A power grid coordinated control method, applicable to the power grid coordinated control system described in any one of claims 1-9, characterized in that: Includes the following steps: S1. Real-time acquisition of operating status signals of core equipment in the power grid and transmission to the corresponding port of the first data selector; S2. Generate a selection signal that arranges the sub-signals in sequence based on a preset time interval; Based on the sorting of sub-signals in the selection signal, the operating status signal received by the corresponding port of the first data selector is collected, and a fault code is generated based on the operating status signal. S3. Match the fault codes with the preset fault identification code table, and determine the faulty equipment in the power grid based on the matching results; S4. If there is a faulty device in the power grid and the power coordination controller is normal, the second data selector selects the first inverter logic of the bidirectional inverter module; if the power coordination controller fails, the second data selector selects the second inverter logic of the bidirectional inverter module; the power supply relationship between the main power grid and the microgrid is coordinated based on the first / second inverter logic.

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