Micro-grid anti-countercurrent optical storage cooperative scheduling method and system

Abstract

The invention relates to the technical field of energy management, and discloses a micro-grid anti-countercurrent optical storage cooperative scheduling method and system, and the method can regulate and control the operation state of an inverter through an anti-countercurrent optical storage cooperative scheduling model, thereby preventing the countercurrent of a micro-grid. Through a simulation platform, strong tracking unscented Kalman filtering is utilized to establish an anti-countercurrent optical storage cooperative scheduling model, the reference power, the high threshold power and the ground threshold power of a bus are set, and a detection module is utilized to obtain the real-time power of the bus after each preset time interval from the starting time; and the control module is used for acquiring real-time power of the inverter, comparing the acquired real-time power with reference power, high-threshold power and low-threshold power respectively, and sending an instruction to the control module by using an anti-countercurrent optical storage cooperative scheduling model according to each comparison result so as to synchronously adjust the running state of the inverter until the end time is reached. According to the technical scheme, the problem of countercurrent of the micro-grid can be solved, and stable operation of the micro-grid is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of energy management, and particularly relates to a method and system for coordinated scheduling of a microgrid to prevent reverse power flow and energy storage. Background Art

[0002] A microgrid refers to a small power system composed of multiple distributed energy resources (such as solar energy, wind energy, etc.) and energy storage systems (such as batteries, supercapacitors, etc.), which can operate independently or be connected to the main grid and have a certain self-regulation ability. The microgrid is an important part of the future smart grid, which realizes the efficient utilization of distributed energy by combining renewable energy and energy storage technology. However, due to the intermittency and volatility of renewable energy, the operation and management of the microgrid face many challenges. When the power generated inside the microgrid exceeds the local load demand, reverse power flow will occur. Reverse power flow may cause equipment such as transmission lines and transformers to be overloaded, increase the operating load of the system, and even cause equipment damage or failure. Therefore, how to prevent the reverse power flow of the microgrid has become a technical problem that needs to be solved urgently. For this reason, the present invention proposes a method and system for coordinated scheduling of a microgrid to prevent reverse power flow and energy storage, which coordinates the operation of photovoltaic power generation and the energy storage system to prevent reverse power flow in the microgrid and achieve stable, economic and efficient operation of the microgrid. Summary of the Invention

[0003] The main object of the present invention is to provide a method and system for coordinated scheduling of a microgrid to prevent reverse power flow and energy storage, so as to solve the problem of reverse power flow in the microgrid.

[0004] The technical solution proposed by the present invention is as follows:

[0005] A method for coordinated scheduling of a microgrid to prevent reverse power flow and energy storage, which is applied to a system for coordinated scheduling of a microgrid to prevent reverse power flow and energy storage; the system includes a microgrid connected to the main grid in parallel, a detection module and a control module; the microgrid and a local load are connected to a bus; the microgrid includes photovoltaic panels and an inverter; the detection module is used to detect the real-time power of the bus; the control module is used to control the opening and closing of the inverter; the method includes:

[0006] Based on a simulation platform, a coordinated scheduling model for preventing reverse power flow and energy storage is established by using strong tracking unscented Kalman filtering;

[0007] Set the reference power, high threshold power and low threshold power of the bus;

[0008] Use the detection module to obtain the real-time power of the bus at each preset time interval since the start time, and compare the obtained real-time power with the reference power, high threshold power and low threshold power respectively;

[0009] According to the result of each comparison, use the anti-reverse current energy storage collaborative scheduling model to issue an instruction to the control module to synchronously adjust the operating state of the inverter until the termination time is reached.

[0010] Preferably, based on the simulation platform, using strong tracking unscented Kalman filter to establish an anti-reverse current energy storage collaborative scheduling model, including:

[0011] Initial state estimation: According to the existing observation data and prior knowledge, use the Kalman filter to perform an initial estimation of the state variables;

[0012] Construct sigma points: Use the mean and covariance matrix of the system state to construct a set of sigma points, including the system state and other possible states within its variance range;

[0013] Nonlinear transformation: Map the sigma points through a nonlinear model, and calculate the mean and covariance matrix of the predicted state;

[0014] Calculate the Kalman gain: According to the covariance matrix of the predicted state and the covariance matrix of the observed value, calculate the Kalman gain;

[0015] Update the state estimation: Use the difference between the Kalman gain and the observed value to update the state estimation;

[0016] Execute the steps of constructing sigma points and subsequent steps until the state estimation converges.

[0017] Preferably, using the detection module to obtain the real-time power of the bus at each preset time interval since the starting time, and comparing the obtained real-time power with the reference power, upper limit power, and lower limit power respectively, including:

[0018] Compare the magnitude of the real-time power obtained from the starting time to the termination time with the reference power;

[0019] If the real-time power is greater than the reference power, determine whether the real-time power is greater than the high threshold power;

[0020] If the real-time power is greater than the high threshold power, feedback the result to the control module;

[0021] If the real-time power is between the reference power and the high threshold power, return for re-detection;

[0022] If the real-time power is less than the reference power, determine whether the real-time power is less than the low threshold power;

[0023] If the real-time power is less than the low threshold power, feedback the result to the control module;

[0024] If the real-time power is between the reference power and the low threshold power, return for re-detection.

[0025] Preferably, according to each comparison result, an instruction is sent to the control module by using the anti-reverse power flow energy storage collaborative scheduling model to synchronously adjust the operating state of the inverter until the termination time, including:

[0026] If the real-time power is greater than the high threshold power, close one of the inverters;

[0027] If the real-time power is less than the low threshold power, detect whether an inverter is in use. If so, disconnect one of the inverters. If not, return for re-detection;

[0028] Execute the comparison of the real-time power and the reference power obtained during the comparison start time to the termination time, and subsequent steps.

[0029] Preferably, when the same microgrid includes multiple inverters with different powers, the high threshold power and the low threshold power are both set according to the power grading of different inverters, and each level of high threshold power or each level of low threshold power corresponds to one inverter; the inverters are turned on in ascending order of power, and the inverters are turned off in descending order of power.

[0030] Preferably, the system further includes a bidirectional watt-hour meter, which is arranged on the bus to detect whether there is reverse current; after sending an instruction to the control module by using the anti-reverse power flow energy storage collaborative scheduling model according to each comparison result to synchronously adjust the operating state of the inverter until the termination time, it further includes:

[0031] Adjust the local load to be at different loads, and adjust the operating state of the inverter according to the load conditions of the local load through the anti-reverse power flow energy storage collaborative scheduling model;

[0032] Detect whether there is reverse current in the bus through the bidirectional watt-hour meter;

[0033] If there is no reverse current in the bus, determine that the anti-reverse power flow energy storage collaborative scheduling model is qualified;

[0034] If there is reverse current in the bus, execute the step of establishing the anti-reverse power flow energy storage collaborative scheduling model by using the strong tracking unscented Kalman filter based on the simulation platform, and subsequent steps.

[0035] Preferably, the system further includes an energy storage device, a photosensitive sensor, and a driving motor; the energy storage device is electrically connected to the photovoltaic panel, and the energy storage device is used to supply power to the main power grid; the photosensitive sensor is communicatively connected to the control module, and the photosensitive sensor is used to detect the light intensity; the driving motor is communicatively connected to the control module, and the driving motor is used to drive the rotation of the photovoltaic panel; when the detection module detects that the real-time power of the bus is greater than the high threshold power and the inverter needs to be put into use, the control module issues an instruction to the driving motor to drive the photovoltaic panel to adjust the angle following the change of the sun angle, so as to improve the power generation efficiency.

[0036] Preferably, the system further includes a watt-hour meter and a current transformer; the watt-hour meter is used to measure the forward active power of the microgrid; the current transformer is used to measure the current generated by the microgrid; the calculation method of the photovoltaic power generation electricity charge is as follows:

[0037] Photovoltaic power generation electricity charge = the electricity quantity shown on the watt-hour meter × the current transformer ratio × the unit price of electricity charge.

[0038] Preferably, the system further includes a server; the server is used for: recording the load demand situation of the local load in the past period of time, and providing weather forecasts; the anti-reverse current energy storage collaborative scheduling model is further used for: summarizing the load demand rules of the local load, thereby predicting the load required by the local load at a certain time period, and adjusting the operation of the photovoltaic panel and the energy storage device according to the weather forecast.

[0039] The present invention also proposes a microgrid anti-reverse current energy storage collaborative scheduling system, which applies the microgrid anti-reverse current energy storage collaborative scheduling method; the system includes a microgrid connected to the main power grid in parallel, a detection module, and a control module; the microgrid and the local load are connected to a bus; the microgrid includes a photovoltaic panel and an inverter; the detection module is used to detect the real-time power of the bus; the control module is used to control the opening and closing of the inverter.

[0040] Through the above technical solutions, the following beneficial effects can be achieved:

[0041] The anti-reverse power flow energy storage and grid-connected collaborative scheduling method proposed by the present invention can adjust the operating state of the inverter through the established anti-reverse power flow energy storage and grid-connected collaborative scheduling model, thereby preventing reverse power flow in the microgrid. In specific applications, an anti-reverse power flow energy storage and grid-connected collaborative scheduling model is established based on a simulation platform, and the reference power, high threshold power, and low threshold power are set respectively according to the actual operating conditions of the power grid and local load. The detection module can obtain the real-time power of the bus after each preset time interval from the starting time, and compare the obtained real-time power with the reference power, high threshold power, and low threshold power respectively. According to the comparison results each time, an instruction is sent to the control module by using the anti-reverse power flow energy storage and grid-connected collaborative scheduling model to synchronously adjust the operating state of the inverter until the end time is reached. To sum up, the anti-reverse power flow energy storage and grid-connected collaborative scheduling method proposed by the present invention can control the microgrid to provide power to the local load according to the load demand of the local load, prevent reverse power flow in the microgrid, and is beneficial to the stable and efficient operation of the microgrid. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0043] Figure 1 It is a flowchart of the steps of the first embodiment of the anti-reverse power flow energy storage and grid-connected collaborative scheduling method of the microgrid of the present invention;

[0044] Figure 2 It is a flowchart of the opening and closing of the inverter of the I bus in an embodiment of the anti-reverse power flow energy storage and grid-connected collaborative scheduling method of the microgrid of the present invention;

[0045] Figure 3 It is a flowchart of the opening and closing of the inverter of the II bus in an embodiment of the anti-reverse power flow energy storage and grid-connected collaborative scheduling method of the microgrid of the present invention.

[0046] The realization, functional characteristics, and advantages of the object of the present invention will be further described in conjunction with the embodiments and with reference to the drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0048] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a certain specific posture (as shown in the attached drawings). If the specific posture changes, the directional indications will also change accordingly.

[0049] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0050] In the present invention, unless otherwise clearly specified and limited, terms such as "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0051] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions conflicts with each other or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0052] The present invention provides a microgrid anti-reverse power flow energy storage and grid-connected collaborative scheduling method and system.

[0053] Please refer to Figures 1 to 3 , in the first embodiment of a microgrid anti-reverse power flow energy storage and grid-connected collaborative scheduling method proposed by the present invention, this method is applied to a microgrid anti-reverse power flow energy storage and grid-connected collaborative scheduling system; the system includes a microgrid connected to the main grid in parallel, a detection module (here it can be a power sensor) and a control module (here it can be a PLC module, i.e., a programmable logic controller module); the microgrid and local loads are connected to a bus; the microgrid includes photovoltaic panels and an inverter; the detection module is used to detect the real-time power of the bus; the control module is used to control the opening and closing of the inverter; this embodiment includes the following steps:

[0054] Step S110: Based on a simulation platform, use a strong tracking unscented Kalman filter to establish an anti-reverse power flow energy storage and grid-connected collaborative scheduling model;

[0055] Strong tracking unscented Kalman filter is an improved Kalman filter algorithm. It adapts to nonlinear systems by introducing nonlinear transformations and uses the method of unscented Kalman filter to update state estimates. Compared with the traditional Kalman filter algorithm, strong tracking unscented Kalman filter can better handle the uncertainties existing in the system model and measurement model, thus obtaining more accurate state estimation results and improving the performance and robustness of the system.

[0056] In this embodiment, the anti-reverse power flow energy storage and power grid coordinated scheduling model is established using Matlab software and Python programming language.

[0057] Step S120: Set the reference power, high threshold power, and low threshold power of the busbar.

[0058] Specifically, the reference power refers to the standard power level during the normal operation of the power system, usually based on the rated power or design capacity of the system. The purpose of setting the reference power is to provide a reference standard for the normal operation of the power system. The reference power, high threshold power, and low threshold power are all determined according to the actual operating conditions of the power grid and local load. Among them, the high threshold power is greater than the reference power, and the low threshold power is less than the reference power. In this embodiment, the reference power is 300kW.

[0059] Step S130: Use the detection module to obtain the real-time power of the busbar at each preset time interval since the start time, and compare the obtained real-time power with the reference power, high threshold power, and low threshold power respectively.

[0060] Specifically, the start time and end time can be determined according to the sunshine duration in the area. In this embodiment, the start time is 8 am, the end time is 5 pm, and the preset time interval is 1 minute.

[0061] Step S140: According to the comparison results each time, use the anti-reverse power flow energy storage and power grid coordinated scheduling model to send instructions to the control module to synchronously adjust the operating state of the inverter until the end time is reached.

[0062] Specifically, if the real-time power exceeds the set high threshold power, the microgrid starts to output power to the local load; if the real-time power is lower than the set high threshold power, the microgrid stops outputting power to the local load.

[0063] The microgrid reverse power flow prevention and energy storage collaborative scheduling method proposed by the present invention can adjust the operating state of the inverter through the established reverse power flow prevention and energy storage collaborative scheduling model, thereby preventing reverse power flow in the microgrid. In specific applications, a reverse power flow prevention and energy storage collaborative scheduling model is established based on a simulation platform, and the reference power, high threshold power, and low threshold power are respectively set according to the actual operating conditions of the power grid and local load. The detection module can obtain the real-time power of the bus at each preset time interval since the start time, and compare the obtained real-time power with the reference power, high threshold power, and low threshold power respectively. According to the result of each comparison, an instruction is sent to the control module by using the reverse power flow prevention and energy storage collaborative scheduling model to synchronously adjust the operating state of the inverter until the end time is reached. To sum up, the microgrid reverse power flow prevention and energy storage collaborative scheduling method proposed by the present invention can control the microgrid to supply power to the local load according to the load demand of the local load, prevent reverse power flow in the microgrid, and is beneficial to the stable and efficient operation of the microgrid.

[0064] In the second embodiment of a microgrid reverse power flow prevention and energy storage collaborative scheduling method proposed by the present invention, based on the first embodiment, step S110 includes the following steps:

[0065] Step S210: Initialize state estimation: Use the Kalman filter to perform an initial estimation of the state variables according to the existing observation data and prior knowledge.

[0066] Step S220: Construct sigma points: Use the mean and covariance matrix of the system state to construct a set of sigma points, including the system state and other possible states within its variance range.

[0067] Step S230: Nonlinear transformation: Map the sigma points through a nonlinear model and calculate the mean and covariance matrix of the predicted state.

[0068] Step S240: Calculate the Kalman gain: Calculate the Kalman gain according to the covariance matrix of the predicted state and the covariance matrix of the observed value.

[0069] Step S250: Update state estimation: Update the state estimation using the difference between the Kalman gain and the observed value.

[0070] Step S260: Execute the steps of constructing sigma points and subsequent steps until the state estimation converges.

[0071] In the third embodiment of a microgrid reverse power flow prevention and energy storage collaborative scheduling method proposed by the present invention, based on the first embodiment, step S130 includes the following steps:

[0072] Step S310: Compare the magnitude of the real-time power obtained from the start time to the end time with the reference power.

[0073] Step S320: If the real-time power is greater than the reference power, determine whether the real-time power is greater than the high threshold power;

[0074] Step S330: If the real-time power is greater than the high threshold power, feedback the result to the control module;

[0075] Step S340: If the real-time power is between the reference power and the high threshold power, return for re-detection;

[0076] Step S350: If the real-time power is less than the reference power, determine whether the real-time power is less than the low threshold power;

[0077] Step S360: If the real-time power is less than the low threshold power, feedback the result to the control module;

[0078] Step S370: If the real-time power is between the reference power and the low threshold power, return for re-detection.

[0079] In one embodiment, the reference power is set to 300 kW, the high threshold power is set to 450 kW, and the low threshold power is set to 200 kW.

[0080] In the fourth embodiment of a microgrid anti-reverse power flow energy storage and grid-connected collaborative scheduling method proposed by the present invention, based on the third embodiment, step S140 includes the following steps:

[0081] Step S410: If the real-time power is greater than the high threshold power, close one of the inverters;

[0082] Step S420: If the real-time power is less than the low threshold power, detect whether an inverter is in use. If so, disconnect one of the inverters. If not, return for re-detection;

[0083] Step S430: Execute the comparison of the real-time power and the reference power obtained during the comparison start time to the end time, and subsequent steps.

[0084] Please refer to Figure 2 , in one embodiment, a total of 4 inverters with a capacity of 110 kW each are connected to the 1# grid connection point, with a total capacity of 440 kW, and are connected to a 1000 kVA transformer. The reference power is set to 300 kW, the high threshold power is set to 450 kW, the low threshold power is set to 200 kW, the start time is 8:00 am, and the end time is 17:00 pm.

[0085] 1# Point of common coupling, determines the inverter input by detecting the real-time power on the 10kV Busbar I every minute starting at 8:00 am every day. Each detection first determines whether the current real-time power is greater than 300kW; if the real-time power is greater than 300kW, it continues to determine whether the real-time power is greater than 450kW; if it is not greater than 450kW, it returns for re-detection; if it is greater than 450kW, it first detects and closes the 1#-1 inverter, and then the second detection closes the 1#-2 inverter, and so on in a cycle. Each detection only attempts to close one inverter until all inverters are input; if the real-time power is less than 300kW, it continues to determine whether the real-time power is greater than 200kW. If it is greater than 200kW, it returns for re-detection. If it is not greater than 200kW, it detects whether there is an inverter in use; if there is no inverter in use, it returns for re-detection; if there is an inverter in use, it disconnects the inverters in sequence according to the detection results until there is no inverter in use. The detection task ends after 17:00 every day, otherwise the detection task is continuously executed in a cycle.

[0086] Preferably, when the same microgrid includes multiple inverters with different powers, both the high threshold power and the low threshold power are set according to the power grading of different inverters. Each level of high threshold power or each level of low threshold power corresponds to one inverter; the inverters are turned on in ascending order of power, and the inverters are turned off in descending order of power.

[0087] Please refer to Figure 3 , in an embodiment, the 2# point of common coupling is connected to 2 inverters of 110kW and 2 inverters of 60kW, with a total capacity of 340kW, and is connected to the 3# 1000kVA transformer. The 3# point of common coupling is connected to 2 inverters of 110kW and 2 inverters of 60kW, with a total capacity of 340kW, and is connected to the 4# 1000kVA transformer. The 4# point of common coupling is connected to 3 inverters of 110kW and 3 inverters of 60kW, with a total capacity of 510kW, and is connected to the 5# 1000kVA transformer. The 5# point of common coupling is connected to 3 inverters of 110kW, 1 inverter of 60kW and 2 inverters of 30kW, with a total capacity of 450kW, and is connected to the 6# 1000kVA transformer. The reference power is set to 300kW, the first-level high threshold power is 340kW, the second-level high threshold power is 370kW, the third-level high threshold power is 450kW, the start time is 8:00 am, and the end time is 17:00 pm.

[0088] At the grid connection points of 2#, 3#, 4#, and 5#, the inverter is determined to be connected by detecting the real-time power on the 10 kV section II bus every minute starting at 8:00 every morning. Each detection first determines whether the current real-time power is greater than 300 kW; if the real-time power is greater than 300 kW, it continues to determine whether the real-time power is greater than 340 kW; if it is not greater than 340 kW, it returns for re-detection; if it is greater than 340 kW, it detects whether all 30 kW inverters are closed; if not all are closed, the 30 kW inverters are closed sequentially according to the detection results, and re-detection is performed each time one is connected. Only one inverter is attempted to be closed each time, until all inverters are connected; if all 30 kW inverters are already in use, it further determines whether the real-time power is greater than 370 kW; if it is not greater than 370 kW, it returns for re-detection; if it is greater than 370 kW, it detects whether all 60 kW inverters are in use; if not all are in use, the 60 kW inverters are closed sequentially according to the detection results, and re-detection is performed each time one is connected. Only one inverter is attempted to be closed each time, until all inverters are connected; if all 60 kW inverters are already in use, it further determines whether the real-time power is greater than 450 kW; if it is not greater than 450 kW, it returns for re-detection; if it is greater than 450 kW, it detects whether all 110 kW inverters are in use; if not all are in use, the 110 kW inverters are closed sequentially according to the detection results, and re-detection is performed each time one is connected. Only one inverter is attempted to be closed each time, until all inverters are connected. If all 110 kW inverters are already in use, it returns for re-detection. The detection task ends after 17:00 every afternoon, otherwise the detection task is continuously looped. The disconnection process of the inverter is the same as above.

[0089] Preferably, the system further includes a bidirectional watt-hour meter, which is arranged on the bus to detect whether there is a reverse current; in the fifth embodiment of a microgrid anti-reverse current energy storage and photovoltaic collaborative scheduling method proposed by the present invention, based on the first embodiment, after step S140, the following steps are further included:

[0090] Step S510: Adjust the local load to be at different loads, and adjust the operating state of the inverter according to the load condition of the local load through the anti-reverse current energy storage and photovoltaic collaborative scheduling model;

[0091] Step S520: Detect whether there is a reverse current on the bus through the bidirectional watt-hour meter;

[0092] Step S530: If there is no reverse current on the bus, determine that the anti-reverse current energy storage and photovoltaic collaborative scheduling model is qualified;

[0093] Step S540: If there is a reverse current on the bus, execute the steps after establishing the anti-reverse current energy storage and photovoltaic collaborative scheduling model using strong tracking unscented Kalman filtering based on the simulation platform.

[0094] Specifically, this embodiment provides an effect verification scheme for the anti-reverse current photovoltaic-storage collaborative scheduling model.

[0095] Preferably, the system further includes an energy storage device, a photosensitive sensor, and a driving motor; the energy storage device is electrically connected to the photovoltaic panel, and the energy storage device is used to supply power to the main grid; the photosensitive sensor is communicatively connected to the control module, and the photosensitive sensor is used to detect the light intensity; the driving motor is communicatively connected to the control module, and the driving motor is used to drive the rotation of the photovoltaic panel; when the detection module detects that the real-time power of the bus is greater than the high threshold power and the inverter needs to be put into use, the control module sends an instruction to the driving motor to drive the photovoltaic panel to adjust the angle following the change of the sun angle to improve the power generation efficiency.

[0096] Specifically, the photovoltaic panel can be adjusted to an appropriate angle according to the load demand of the local load and the power reserve of the energy storage device to meet the power supply to the local load and charge the energy storage device. The number of driving motors is 2 to drive the photovoltaic panel to adjust the angle of the photovoltaic panel in 2 dimensions (usually the east-west direction and the north-south direction) to improve the power generation efficiency.

[0097] Preferably, the system further includes a metering watt-hour meter and a current transformer; the metering watt-hour meter is used to measure the forward active power of the microgrid; the current transformer is used to measure the current generated by the microgrid; the calculation method of photovoltaic power generation electricity fee is:

[0098] Photovoltaic power generation electricity fee = the electricity quantity shown on the metering watt-hour meter × the current transformer ratio × the unit price of electricity fee.

[0099] Preferably, the system further includes a server; the server is used for: recording the load demand situation of the local load in the past period of time and providing weather forecasts; the anti-reverse current photovoltaic-storage collaborative scheduling model is further used for: summarizing the load demand law of the local load, thereby predicting the load required by the local load at a certain time period, and adjusting the operation of the photovoltaic panel and the energy storage device according to the weather forecast.

[0100] The anti-reverse current photovoltaic-storage collaborative scheduling model can predict the power generation capacity of the photovoltaic panels according to future weather conditions, and combine the power reserve of the energy storage device to evaluate whether the power generation after the photovoltaic panels and the reserve power of the energy storage device can meet the load demand of the local load, and adjust the operation of the photovoltaic panels and the energy storage device accordingly. When the load demand of the local load can be met, the local load is powered by the photovoltaic panels or the energy storage device alone, or the photovoltaic panels stop working after assuming a certain electrical load, and the remaining electrical load is borne by the energy storage device; if the load demand of the local load cannot be met, the photovoltaic panels will always be at the optimal power generation angle, and while powering the local load, store energy for the energy storage device in advance to ensure the stable power supply of the microgrid in subsequent periods.

[0101] The present invention also provides a microgrid anti-reverse current photovoltaic-storage collaborative scheduling system, which applies the microgrid anti-reverse current photovoltaic-storage collaborative scheduling method; the system includes a microgrid connected to the main grid in parallel, a detection module and a control module; the microgrid and the local load are connected to the bus; the microgrid includes photovoltaic panels and an inverter; the detection module is used to detect the real-time power of the bus; the control module is used to control the opening and closing of the inverter.

[0102] Furthermore, the system further includes a protection device and an alarm device; the protection device is communicatively connected to the control module, and the protection device is used to adjust the photovoltaic power generation when the positive active power and current of the microgrid reach the set value; the alarm device is used to issue an alarm when the protection device fails.

[0103] Specifically, the protection device includes a main protection and a backup protection; the main protection is used to automatically switch and control when the positive active power and current in the microgrid reach the set value to adjust the photovoltaic power generation; the backup protection is used to issue an alarm through the alarm device after the main protection fails to prompt manual cutting of the photovoltaic power generation switch.

[0104] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0105] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made by using the description and drawings of the present invention under the concept of the present invention, or directly / indirectly applied to other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A microgrid anti-reverse power flow energy storage and grid-connected photovoltaic collaborative scheduling method, characterized in that Applied to the anti-reverse power flow energy storage and coordinated dispatching system of a microgrid; the system includes a microgrid connected to the main grid in parallel, a detection module, and a control module; the microgrid and local loads are connected to a bus; the microgrid includes photovoltaic panels and an inverter; The detection module is used to detect the real-time power of the bus; The control module is used to control the opening and closing of the inverter; the method includes: Based on a simulation platform, use strong tracking unscented Kalman filter to establish an anti-reverse power flow energy storage and coordinated dispatching model; Set the reference power, high threshold power, and low threshold power of the bus; Use the detection module to obtain the real-time power of the bus at each preset time interval since the start time, and compare the obtained real-time power with the reference power, high threshold power, and low threshold power respectively; According to the comparison results each time, use the anti-reverse power flow energy storage and coordinated dispatching model to send instructions to the control module to synchronously adjust the operating state of the inverter until the end time is reached.

2. The microgrid anti-reverse power flow energy storage and power generation coordinated scheduling method according to claim 1, wherein The establishing of the anti-reverse power flow energy storage and coordinated dispatching model based on a simulation platform using strong tracking unscented Kalman filter includes: Initial state estimation: According to existing observation data and prior knowledge, use a Kalman filter to perform an initial estimation of the state variables; Construct sigma points: Use the mean and covariance matrix of the system state to construct a set of sigma points, including the system state and other possible states within its variance range; Nonlinear transformation: Map the sigma points through a nonlinear model, and calculate the mean and covariance matrix of the predicted state; Calculate the Kalman gain: According to the covariance matrix of the predicted state and the covariance matrix of the observed value, calculate the Kalman gain; Update state estimation: Use the difference between the Kalman gain and the observed value to update the state estimation; Execute the steps of constructing sigma points and subsequent steps until the state estimation converges.

3. The microgrid anti-reverse power flow energy storage and power generation collaborative scheduling method according to claim 1, characterized in that The obtaining of the real-time power of the bus at each preset time interval since the start time using the detection module and comparing the obtained real-time power with the reference power, upper limit power, and lower limit power respectively includes: Compare the size of the real-time power obtained from the start time to the end time with the reference power; If the real-time power is greater than the reference power, determine whether the real-time power is greater than the high threshold power; If the real-time power is greater than the high threshold power, feedback the result to the control module; If the real-time power is between the reference power and the high threshold power, return for re-detection; If the real-time power is less than the reference power, determine whether the real-time power is less than the low threshold power; If the real-time power is less than the low threshold power, feedback the result to the control module; If the real-time power is between the reference power and the low threshold power, return for re-detection.

4. The microgrid anti-reverse power flow energy storage and grid-connected collaborative scheduling method according to claim 3, characterized in that, The sending of instructions to the control module according to the comparison results each time using the anti-reverse power flow energy storage and coordinated dispatching model to synchronously adjust the operating state of the inverter until the end time is reached includes: If the real-time power is greater than the high threshold power, close one of the inverters; If the real-time power is less than the low threshold power, detect whether an inverter is in use. If so, disconnect one of the inverters. If not, return for re-detection; Execute the comparison of the real-time power obtained from the start time to the end time with the reference power, and subsequent steps.

5. The microgrid anti-reverse power flow energy storage and grid-connected collaborative scheduling method according to claim 4, wherein When the same microgrid includes multiple inverters with different powers, the high threshold power and the low threshold power are both set according to the power grading of different inverters, and each level of high threshold power or each level of low threshold power corresponds to one inverter; the inverters are turned on in ascending order of power, and the inverters are turned off in descending order of power.

6. The microgrid anti-reverse power flow energy storage and grid-connected collaborative scheduling method according to claim 1, characterized in that The system further includes a bidirectional electricity meter, which is arranged on the bus to detect whether there is a reverse current; according to each comparison result, the anti-reverse current energy storage and photovoltaic collaborative scheduling model is used to send an instruction to the control module to synchronously adjust the operating state of the inverter until the end time is reached. Subsequently, it also includes: Adjust the local load to different loads, and according to the load conditions of the local load, the anti-reverse current energy storage and photovoltaic collaborative scheduling model is used to adjust the operating state of the inverter; Detect whether there is a reverse current in the bus through the bidirectional electricity meter; If there is no reverse current in the bus, determine that the anti-reverse current energy storage and photovoltaic collaborative scheduling model is qualified; If there is a reverse current in the bus, execute the steps of establishing an anti-reverse current energy storage and photovoltaic collaborative scheduling model based on a simulation platform using strong tracking unscented Kalman filtering, and subsequent steps.

7. The microgrid anti-reverse power flow energy storage and grid-connected collaborative scheduling method according to claim 1, characterized in that The system further includes an energy storage device, a photosensitive sensor, and a driving motor; the energy storage device is electrically connected to the photovoltaic panel, and the energy storage device is used to supply power to the main grid; the photosensitive sensor is communicatively connected to the control module, and the photosensitive sensor is used to detect the light intensity; the driving motor is communicatively connected to the control module, and the driving motor is used to drive the photovoltaic panel to rotate; when the detection module detects that the real-time power of the bus is greater than the high threshold power and the inverter needs to be put into use, the control module sends an instruction to the driving motor to drive the photovoltaic panel to adjust the angle according to the change of the sun angle to improve the power generation efficiency.

8. The microgrid anti-reverse power flow energy storage and grid-connected collaborative scheduling method according to claim 1, wherein, The system further includes a metering electricity meter and a current transformer; the metering electricity meter is used to measure the forward active power of the microgrid; the current transformer is used to measure the current generated by the microgrid; the calculation method of photovoltaic power generation electricity bill is: Photovoltaic power generation electricity bill = the electricity quantity shown on the metering electricity meter × the current transformer ratio × the electricity price per unit.

9. The microgrid anti-reverse power flow energy storage and power generation collaborative scheduling method according to claim 7, wherein The system further includes a server; the server is used to: record the load demand conditions of the local load in the past period of time, and provide weather forecasts; the anti-reverse current energy storage and photovoltaic collaborative scheduling model is also used to: summarize the load demand rules of the local load, so as to predict the load required by the local load at a certain time period, and adjust the operation of the photovoltaic panel and the energy storage device according to the weather forecast.

10. A microgrid anti-reverse power flow energy storage and grid-connected collaborative scheduling system, characterized in that, Apply the microgrid anti-backflow photovoltaics and energy storage collaborative scheduling method according to any one of claims 1-9; the system includes a microgrid connected to the main grid, a detection module, and a control module; the microgrid and local loads are connected to a bus; the microgrid includes photovoltaic panels and an inverter; the detection module is used to detect the real-time power of the bus; the control module is used to control the opening and closing of the inverter.

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