Power distribution network fault processing method, device and system

Abstract

The invention provides a power distribution network fault processing method, device and system, and belongs to the technical field of power distribution network automation. The method comprises the following steps: controlling an Internet of Things terminal to carry out island detection on a grid-connected point in a power distribution network; when it is determined that the island detection result is that the island range exists, an Internet of Things terminal is controlled to send an opening instruction to a grid-connected switch, so that the island range is isolated from a main network in the power distribution network; and controlling network equipment to send a charging instruction or a discharging instruction to an energy storage device through the Internet of Things terminal at least based on the battery charge state of the distributed power supply in the island range, so as to realize power balance in the island range. According to the invention, the defects that most of power distribution network fault processing schemes based on the Internet of Things in the prior art can only realize simple fault alarm and remote monitoring, and lacks an automatic fault processing mechanism and cloud intelligent decision support are overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of distribution network automation, and in particular to a distribution network fault processing method, a distribution network fault processing device, a distribution network fault processing system, a machine-readable storage medium, and a computer program product. Background Art

[0002] Traditional distribution network fault handling relies on manual inspections and centralized control, resulting in slow response, inaccurate positioning, and long recovery times, severely impacting power quality and user experience. With the rapid development of the Internet of Things (IoT), applying IoT technology to distribution network fault handling has become a key approach to improving the intelligence of distribution networks.

[0003] However, most of the existing IoT-based distribution network fault handling solutions can only achieve simple fault alarms and remote monitoring, and lack automated fault handling mechanisms and cloud-based intelligent decision-making support. Summary of the Invention

[0004] The purpose of the embodiments of the present invention is to provide a distribution network fault handling method, device and system to address the defects of the existing distribution network fault handling solutions based on the Internet of Things, which can only achieve simple fault alarms and remote monitoring, but lack automated fault handling mechanisms and cloud-based intelligent decision support.

[0005] To achieve the above objectives, an embodiment of the present invention provides a method for handling a distribution network fault, comprising:

[0006] Control the IoT terminal to perform island detection on the grid connection points in the distribution network;

[0007] When it is determined that the island detection result shows that an island range exists, controlling the Internet of Things terminal to send a tripping instruction to the grid-connected switch to isolate the island range from the main grid in the distribution network;

[0008] The control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, so as to achieve power balance within the island range.

[0009] Optionally, the control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, including:

[0010] The control network device sends a discharge instruction to the energy storage device through the Internet of Things terminal when the state of charge of the battery of the distributed power supply is less than a first set state of charge threshold.

[0011] Optionally, the control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, including:

[0012] The control network device sends a charging instruction to the energy storage device through the Internet of Things terminal when the generated power of the distributed power source is greater than the load power within the island range and the battery state of charge of the distributed power source is less than a second set state of charge threshold.

[0013] Optionally, when it is determined that the islanding detection result indicates that an islanding range exists, after controlling the IoT terminal to send a tripping instruction to the grid-connected switch, the method further includes:

[0014] The control Internet of Things terminal analyzes abnormal data within the island range to identify the fault area;

[0015] The Internet of Things terminal is controlled to send a tripping instruction to the grid-connected switch to isolate the fault area within the island range.

[0016] Optionally, the method further includes:

[0017] Based on the predicted output power of the distributed power supply in the island range, the output power of the energy storage device in the island range and the load priority in the island range, the load power supply in the island range is redistributed; the load priority in the island range includes the priority of the historical load in the fault area and the priority of the load in the non-fault area in the island range except the fault area.

[0018] Optionally, the redistribution of load power supply within the island range based on the predicted output power of the distributed power sources within the island range, the output power of the energy storage device within the island range, and the load priority within the island range includes:

[0019] When the priority of the load in the non-fault area is higher than the priority of the historical load in the fault area, the control network device sends a closing instruction to the grid-connected switch through the Internet of Things terminal, so that at least one of the predicted output power of the distributed power supply in the island range, the output power of the energy storage device in the island range and the power supply power of the main grid can supply power to the load in the non-fault area; and the backup power supply is controlled to supply power to the fault area through the Internet of Things terminal.

[0020] Optionally, during peak electricity price periods, the IoT terminal is used to control the energy storage device to supply power to the loads in the non-fault area; during low electricity price periods, the IoT terminal is used to control partial load operation in the fault area.

[0021] Optionally, the method further includes:

[0022] Control the IoT terminal to perform island detection on the grid connection points in the distribution network;

[0023] When it is determined that the islanding detection does not result in an islanding range, controlling the output frequency of the energy storage device to be consistent with the frequency of the main grid through the Internet of Things terminal;

[0024] When the voltage of the grid-connected point is within the set normal voltage range, the Internet of Things terminal is controlled to send a closing instruction to the grid-connected switch to merge the island range with the main grid in the distribution network.

[0025] Optionally, the controlling the IoT terminal to perform island detection on a grid connection point in the distribution network includes:

[0026] Control the Internet of Things terminal to perform the first island detection on the grid connection point in the distribution network using a passive detection method;

[0027] When the detection result of the first island detection shows that an island range exists, a primary alarm is triggered;

[0028] When a primary alarm is triggered, the IoT terminal is controlled to perform a second island detection on the grid connection point in the distribution network using an active detection method;

[0029] Among them, when the detection result of the second island detection shows that an island range exists, the island detection result is determined to be that an island range exists; when the detection result of the second island detection shows that no island range exists, the island detection result is determined to be that no island range exists.

[0030] Optionally, the passive detection method includes any one of a voltage / frequency threshold detection method, a phase mutation detection method, and a harmonic distortion rate detection method; the active detection method includes any one of an active frequency offset method, a sliding mode frequency drift method, and a reactive power disturbance method.

[0031] On the other hand, an embodiment of the present invention further provides a distribution network fault handling device, comprising:

[0032] The first island detection module controls the IoT terminal to perform island detection on the grid connection points in the distribution network;

[0033] a first isolation module, which controls the IoT terminal to send a tripping instruction to the grid-connected switch when determining that the island detection result indicates that an island range exists, so as to isolate the island range from the main grid in the distribution network;

[0034] A balancing control module controls the network device to send a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, so as to achieve power balance within the island range.

[0035] Optionally, the control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, including:

[0036] The control network device sends a discharge instruction to the energy storage device through the Internet of Things terminal when the state of charge of the battery of the distributed power supply is less than a first set state of charge threshold.

[0037] Optionally, the control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, including:

[0038] The control network device sends a charging instruction to the energy storage device through the Internet of Things terminal when the generated power of the distributed power source is greater than the load power within the island range and the battery state of charge of the distributed power source is less than a second set state of charge threshold.

[0039] Optionally, the device further includes:

[0040] An identification module is used to control the IoT terminal to analyze abnormal data within the island range and identify the fault area;

[0041] The second isolation module is used to control the Internet of Things terminal to send a tripping instruction to the grid-connected switch to isolate the fault area within the island range.

[0042] Optionally, the device further includes:

[0043] An allocation module is used to redistribute the load power supply within the island range based on the predicted output power of the distributed power supply within the island range, the output power of the energy storage device within the island range, and the load priority within the island range; the load priority within the island range includes the priority of the historical load of the fault area and the priority of the load in the non-fault area within the island range except the fault area.

[0044] Optionally, the redistribution of load power supply within the island range based on the predicted output power of the distributed power sources within the island range, the output power of the energy storage device within the island range, and the load priority within the island range includes:

[0045] When the priority of the load in the non-fault area is higher than the priority of the historical load in the fault area, the control network device sends a closing instruction to the grid-connected switch through the Internet of Things terminal, so that at least one of the predicted output power of the distributed power supply in the island range, the output power of the energy storage device in the island range and the power supply power of the main grid can supply power to the load in the non-fault area; and the backup power supply is controlled to supply power to the fault area through the Internet of Things terminal.

[0046] Optionally, during peak electricity price periods, the IoT terminal is used to control the energy storage device to supply power to the loads in the non-fault area; during low electricity price periods, the IoT terminal is used to control partial load operation in the fault area.

[0047] Optionally, the device further includes:

[0048] The second island detection module is used to control the IoT terminal to perform island detection on the grid connection points in the distribution network;

[0049] A frequency control module, configured to control the output frequency of the energy storage device to be consistent with the frequency of the main grid through an IoT terminal when it is determined that the islanding detection does not result in an islanding range;

[0050] The grid-connected module is used to control the Internet of Things terminal to send a closing instruction to the grid-connected switch when the voltage of the grid-connected point is within the set normal voltage range, so as to merge the island range with the main grid in the distribution network.

[0051] On the other hand, an embodiment of the present invention further provides a distribution network fault handling system, comprising:

[0052] The IoT terminal is used to perform islanding detection on the grid connection point in the distribution network; and when it is determined that the islanding detection result indicates that an islanding range exists, it sends a tripping instruction to the grid connection switch;

[0053] A grid-connected switch, configured to isolate the island range from the main grid in the distribution network in response to the opening instruction;

[0054] A network device, configured to send a charging instruction or a discharging instruction to the energy storage device via the IoT terminal based on at least the battery charge state of the distributed power supply within the island;

[0055] An energy storage device is configured to perform charging processing in response to the charging instruction or to perform discharging processing in response to the discharging instruction, so as to achieve power balance within the island range.

[0056] On the other hand, the present invention further provides a machine-readable storage medium having a computer program stored thereon, which implements the above-mentioned distribution network fault processing method when executed by a processor.

[0057] On the other hand, the present invention further provides a computer program product, comprising a computer program, wherein the computer program implements the above-mentioned distribution network fault processing method when executed by a processor.

[0058] Through the above technical solution, the embodiments of the present invention, through a four-layer architecture consisting of network devices + IoT terminals + grid-connected switches + energy storage devices, enable IoT terminals to perceive fault characteristics in real time, grid-connected switches to control the connection and disconnection of isolated islands from the main grid, energy storage devices to dynamically regulate power supply, and network devices to globally optimize power supply processing strategies, thereby ensuring the safe and stable operation of the distribution network. Through a closed-loop architecture of "fast terminal perception - grid-connected switch control isolation - flexible energy storage regulation - cloud-based global optimization," the embodiments of the present invention address the lack of automated fault handling mechanisms and cloud-based intelligent decision-making support in existing IoT-based distribution network fault handling solutions.

[0059] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0061] Figure 1 This is one of the flow charts of the distribution network fault processing method provided by the present invention;

[0062] Figure 2 This is the second flow chart of the distribution network fault processing method provided by the present invention;

[0063] Figure 3 It is a structural diagram of the distribution network fault processing device provided by the present invention;

[0064] Figure 4 It is a structural diagram of the distribution network fault processing system provided by the present invention. DETAILED DESCRIPTION

[0065] The following describes the specific implementation of the embodiment of the present invention in detail with reference to the accompanying drawings. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiment of the present invention and is not used to limit the embodiment of the present invention.

[0066] Explanation of technical terms involved in the present invention

[0067] Islanding effect: The islanding effect refers to the phenomenon that when the distributed power sources (such as photovoltaic grid-connected power generation systems) installed at various user ends stop working due to a fault accident or power outage maintenance, they fail to detect the power outage in time and cannot quickly disconnect themselves from the mains power network, forming a self-sufficient power supply island phenomenon in which the photovoltaic grid-connected power generation system supplies power to the surrounding loads and the power company cannot control it.

[0068] Method Example

[0069] Please refer to Figure 1 , an embodiment of the present invention provides a distribution network fault processing method, comprising:

[0070] Step 100: Control the Internet of Things terminal to perform island detection on the grid connection point in the distribution network.

[0071] The present invention handles distribution network faults based on a collaborative system architecture of "network equipment + IoT terminal + grid-connected switch + energy storage device". The network equipment can use various devices that play an analytical and decision-making role in the cloud, such as a distribution cloud master station (referred to as the cloud master station). The network equipment of the embodiment of the present invention is described using the cloud master station as an example. The IoT terminal has a communication module (such as a 5G communication module, etc.) that can communicate with the network equipment, grid-connected switch, and energy storage device respectively.

[0072] This embodiment of the present invention first controls an IoT terminal to perform islanding detection on a grid connection point in the distribution network. Islanding detection is the detection of the islanding effect. In this embodiment of the present invention, islanding detection can be performed on grid connection points in the distribution network using a combination of passive and active detection methods.

[0073] The controlling of the IoT terminal to perform island detection on the grid connection point in the distribution network includes:

[0074] Step 110: Control the Internet of Things terminal to perform a first island detection on the grid connection point in the distribution network using a passive detection method.

[0075] Step 120: When the detection result of the first island detection shows that an island range exists, a primary alarm is triggered.

[0076] The passive detection method includes any one of a voltage / frequency threshold detection method, a phase mutation detection method, and a harmonic distortion rate detection method. That is, the passive detection method can select a voltage / frequency threshold detection method, a phase mutation detection method, or a harmonic distortion rate detection method. The embodiment of the present invention is described using the voltage / frequency threshold detection method as an example. The IoT terminal collects the grid connection point voltage U (unit: volt / V) and frequency f (unit: hertz / Hz) at a sampling rate of 10kHz. The IoT terminal calculates the voltage change rate dU / dt and the frequency deviation ΔZ / Δt. If dU / dt>10%Un / s and Δf>0.5Hz / s, a primary alarm is triggered.

[0077] In other embodiments, the IoT terminal in the phase mutation detection method determines the formation of an islanding effect by the phase difference mutation of the voltage and current at the grid connection point. A phase difference threshold (for example, ±5°) is set, and an island is formed when the phase difference exceeds the set phase difference threshold. The IoT terminal in the harmonic distortion rate detection method utilizes the low voltage harmonic distortion rate (Total Harmonic Distortion, THD) characteristic (usually <5%) during normal operation of the distribution network. When an island is formed, the load impedance is significantly higher than the grid impedance, causing the harmonic current to generate a high THD voltage at the load end. The formation of an island is determined by monitoring whether the THD exceeds a threshold (such as 5%). The voltage harmonic distortion rate Among them, U1 is the effective value of the fundamental voltage, U2, U3, ..., U n is the effective value of each harmonic voltage.

[0078] Step 130: When the primary alarm is triggered, control the IoT terminal to perform a second islanding detection on the grid connection point in the distribution network using an active detection method.

[0079] If the second islanding detection result indicates that an islanding range exists, the islanding detection result is determined to be an islanding range; if the second islanding detection result indicates that an islanding range does not exist, the islanding detection result is determined to be an islanding range not existing. The active detection method includes any one of an active frequency shift method, a sliding mode frequency drift method, and a reactive power perturbation method. That is, the active detection method can select the active frequency shift method, the sliding mode frequency drift method, or the reactive power perturbation method.

[0080] For example, the embodiment of the present invention is illustrated by taking the reactive power disturbance method as an example. The IoT terminal is controlled to inject a disturbance signal of a set frequency (for example, 12.5 Hz) into the power grid. If the impedance change rate ΔZ / Δt exceeds a threshold value (such as 20Ω / s), it is determined that an island is formed. In other embodiments, the active frequency offset method actively disturbs the output current frequency of the grid-connected inverter to deviate from the rated frequency of the grid (such as 50 Hz), thereby triggering a frequency protection mechanism when an island occurs. The sliding mode frequency drift method forms a positive feedback mechanism of frequency drift by controlling the phase difference between the output current of the inverter and the voltage at the grid connection point. When the distribution network is normal, the phase difference is clamped close to zero by the power grid; after an island occurs, the accumulated phase difference causes the frequency to continue to deviate from the rated value until protection is triggered.

[0081] Step 300: When it is determined that the island detection result shows that an island range exists, control the Internet of Things terminal to send a tripping instruction to the grid-connected switch to isolate the island range from the main grid in the distribution network.

[0082] When the detection result of the second island detection shows that there is an island range, the Internet of Things terminal is controlled to send a tripping instruction to the grid-connected switch to isolate the island range from the main grid in the distribution network. The island range refers to the area where the distributed power source (mainly refers to photovoltaic power generation, wind power discharge, hydropower, hydrogen energy, etc. excluding energy storage devices, and the embodiment of the present invention takes photovoltaic power generation as an example) continues to supply power after being disconnected from the main grid. The embodiment of the present invention can use the Internet of Things terminal to quickly collect the power information of each load before the fault and the rated power and adjustment capability of the distributed power source in the power outage line, and upload this information to the cloud master station. The cloud master station determines a reasonable island range based on this information and sends an island division instruction to the Internet of Things terminal. It should be noted that after the island range is isolated from the main grid in the distribution network, the power generation device (photovoltaic power generation, wind power discharge, energy storage device, etc.) connected to the power outage line continues to be self-sufficient in power supply to maintain the safe and stable operation of the island.

[0083] The embodiment of the present invention controls the Internet of Things terminal to send a tripping instruction to the grid-connected switch, thereby isolating the island range from the main grid in the distribution network, achieving rapid physical isolation, preventing the spread of faults, and ensuring equipment safety.

[0084] Step 500: Control the network device to send a charging instruction or a discharging instruction to the energy storage device through the IoT terminal based on at least the battery charge state of the distributed power supply within the island range, so as to achieve power balance within the island range.

[0085] During island operation, the cloud master controls the charging and discharging of energy storage devices through IoT terminals based on data trends within the island to maintain power balance within the island. If an imbalance in supply and demand occurs on the island, the cloud master adjusts the energy storage device's charging and discharging strategy to accommodate load fluctuations.

[0086] In one embodiment, the control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based at least on the battery charge state of the distributed power supply within the island range, including: when the battery charge state of the distributed power supply is less than a first set charge state threshold, the control network device sends a discharging instruction to the energy storage device through the Internet of Things terminal.

[0087] For example, if a power grid failure occurs or the state of charge (SOC) of a distributed power source (e.g., photovoltaic) battery is less than 30%, indicating insufficient photovoltaic power generation and requiring the energy storage device to discharge, the IoT terminal immediately sends a discharge instruction to the energy storage device via the communication module. The energy storage device discharges in response to the discharge instruction to achieve power balance within the island. Specifically, the IoT terminal sends the discharge instruction to the grid-connected switch, which sends the discharge instruction to the energy storage device, which then discharges in response to the discharge instruction.

[0088] In another embodiment, the control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based at least on the battery charge state of the distributed power supply within the island range, including: when the generated power of the distributed power supply is greater than the load power within the island range and the battery charge state of the distributed power supply is less than a second set charge state threshold, the control network device sends a charging instruction to the energy storage device through the Internet of Things terminal.

[0089] For example, if the photovoltaic power generation is greater than the load power within the island and the photovoltaic battery's state of charge (SOC) is less than 80%, it indicates excess photovoltaic power generation and the excess photovoltaic power needs to be stored in an energy storage device. The IoT terminal then sends a charging instruction to the energy storage device, which then charges in response to the discharge instruction to achieve power balance within the island. Specifically, the IoT terminal sends a charging instruction to the grid-connected switch, which then sends a charging instruction to the energy storage device, which then charges in response to the charging instruction.

[0090] Therefore, the cloud master station controls the charging and discharging of the energy storage device through the IoT terminal based on the data change trend within the island, thereby maintaining power balance within the island.

[0091] The embodiment of the present invention integrates the passive detection method with the active detection method, realizing a leapfrog upgrade of the microgrid from "passive protection" to "active self-healing", and providing a complete technical path for the construction of a highly reliable and highly resilient distributed energy network for the new power system. The embodiment of the present invention uses a four-layer architecture of network equipment + Internet of Things terminal + grid-connected switch + energy storage device to realize the real-time perception of fault characteristics by the Internet of Things terminal, the connection and disconnection of the island range with the main grid by the grid-connected switch, the dynamic regulation of power supply by the energy storage device, and the global optimization of power supply processing strategy by the network equipment to ensure the safe and stable operation of the distribution network. The embodiment of the present invention solves the problem of the lack of automated fault handling mechanism and cloud-based intelligent decision-making support in the existing distribution network fault handling scheme based on the Internet of Things through the closed-loop architecture of "terminal rapid perception-grid-connected switch control isolation-energy storage flexible regulation-cloud-based global optimization".

[0092] For other aspects of the present invention, please refer to Figure 2 In step 300, when it is determined that the island detection result indicates that an island range exists, after controlling the IoT terminal to send a tripping instruction to the grid-connected switch, the method further includes:

[0093] Step 410: Control the IoT terminal to analyze the abnormal data in the island range and identify the fault area. Step 420: Control the IoT terminal to send a tripping instruction to the grid-connected switch to isolate the fault area in the island range.

[0094] For example, the control Internet of Things terminal uses a trained machine learning model (such as a long short-term memory network or a random forest model, etc.) to analyze the abnormal data in the island range (such as abnormal voltage, frequency, harmonic distortion rate and phase angle, etc.) to identify the fault type. The machine learning model can be supervised based on the sample abnormal data and the fault type label of the sample abnormal data. The control Internet of Things terminal then uses the propagation time difference of the traveling wave generated by the fault on the transmission line to calculate the location of the fault point based on the double-end traveling wave ranging method, thereby determining the fault area. The control Internet of Things terminal then sends a tripping command to the grid-connected switch to isolate the fault area within the island range. This achieves optimized scheduling isolation, further discovers and isolates the fault area within the island range, and prevents the spread of the fault.

[0095] In other aspects of the embodiment of the present invention, after step 500, the following steps are further included:

[0096] Step 600: Redistribute the power supply to the loads within the island range based on the predicted output power of the distributed power sources within the island range, the output power of the energy storage device within the island range, and the load priority within the island range; the load priority within the island range includes the priority of the historical loads in the fault area and the priority of the loads in the non-fault areas within the island range except the fault area.

[0097] In this embodiment of the present invention, the cloud master control station formulates a reasonable fault recovery plan based on the grid's operating status and power flow distribution within the isolated island. During the fault recovery process, the cloud master control station remotely controls the grid-connected switches via an IoT terminal, isolating the faulty area and restoring power to non-faulty areas.

[0098] In one embodiment, the reallocation of power supply to the loads within the island range based on the predicted output power of the distributed power sources within the island range, the output power of the energy storage device within the island range, and the load priority within the island range includes: when the priority of the load in the non-fault area is higher than the priority of the historical load in the fault area, controlling the network device to send a closing instruction to the grid-connected switch through the Internet of Things terminal, so that at least one of the predicted output power of the distributed power sources within the island range, the output power of the energy storage device within the island range, and the power supply power of the main grid supplies power to the loads in the non-fault area; and controlling the backup power supply to supply power to the fault area through the Internet of Things terminal.

[0099] In the embodiment of the present invention, the cloud master station performs global energy scheduling. After receiving the fault alarm, the cloud master station isolates itself in the fault area, calls the historical load of the fault area and the predicted output power of photovoltaics, generates an optimized scheduling strategy, and reallocates the power supply priority according to the importance of the load and the status of the energy storage device.

[0100] For example, a city's power grid covers critical facilities such as Industrial Area A, Commercial Area B, Residential Area C, and Hospital D. One day, the grid's cloud master station receives a fault alert for a transmission line, requiring the partial load shift from Industrial Area A, which is supplied by that line. The fault occurs in Industrial Area A. Commercial Area B, Residential Area C, and Hospital D are not affected. To address this, the system needs to re-prioritize power supply based on historical load data from Industrial Area A and the photovoltaic power predicted by a machine learning model, combined with the real-time status of energy storage devices and load importance.

[0101] First, data collection and analysis are performed. Machine learning models (such as long short-term memory networks) are used to predict that the photovoltaic output power in the next hour will be 50MW (based on historical weather data and real-time irradiance). Historical data shows that the load peak in Industrial Area A, the fault area, is between 18:00 and 20:00, with an average power of 30MW. The current total load of the power grid is 200MW, of which Industrial Area A accounts for 30MW, Commercial Area B accounts for 40MW, Residential Area C accounts for 50MW, and Hospital D accounts for 20MW. Energy storage device status: battery energy storage remaining capacity is 40MWh, and the maximum charge and discharge power is 20MW. The load priority is: Hospital D (critical load) > Residential Area C > Commercial Area B > Industrial Area A.

[0102] Based on the concept of isolating the faulty area and restoring power to non-faulty areas, power supply priorities are adjusted. For the non-faulty area, the first step is to ensure critical loads. Hospital D maintains full power of 20MW. The control network equipment sends a closing command to the grid-connected switch via an IoT terminal, and Hospital D is directly powered by the main grid. The second step is to utilize photovoltaic and energy storage devices. The control network equipment sends a closing command to the grid-connected switch via an IoT terminal. The predicted photovoltaic power of 50MW is preferentially supplied to Residential Area C (50MW demand), with the remaining shortfall being supplemented by the main grid. The energy storage device discharges 20MW, which, together with the remaining photovoltaic power (50MW - 50MW = 0), supports a portion of the load (20MW) in Commercial Area B. The remaining 20MW demand is covered by the main grid, thus ensuring power restoration in the non-faulty area. For the faulty area, the third step is to transfer the load from Industrial Area A. The original 30MW load in Industrial Area A is transferred to the backup power source. The backup power source includes a backup line, which can either reduce non-critical loads through demand response mechanisms or activate emergency generators. Due to the fault, the backup line capacity is limited, and can only provide 10MW. The remaining 20MW of demand is reduced through the demand response mechanism, or emergency generators are activated. The load redistribution strategy is shown in Table 1 below:

[0103] Table 1

[0104]

[0105] The cloud master sends the optimized charging and discharging strategy to the IoT terminal, which then forwards it to the energy storage device. The energy storage device then supplies power to Commercial Area B.

[0106] In addition, in other aspects of the embodiments of the present invention, the power supply strategy can also be adjusted based on electricity prices. During peak electricity price periods, the IoT terminal is used to control the energy storage device to supply power to the loads in the non-fault area; during low electricity price periods, the IoT terminal is used to control partial load operation in the fault area. For example, based on economic considerations. During peak electricity price periods (18:00-22:00), the energy storage device is used for discharge first to reduce the purchase of high-priced electricity from the power grid. And part of the load of industrial area A is adjusted to operate during low electricity price periods (such as after 22:00) to reduce electricity costs.

[0107] By combining photovoltaic forecasts, energy storage device status, and real-time electricity prices, this embodiment of the present invention allows the cloud master station to rapidly adjust power supply priorities after a fault, ensuring that critical loads (such as hospitals) in non-faulty areas are not affected while optimizing the economic efficiency and stability of overall grid operation. This invention enables global energy scheduling to dynamically make power supply decisions in complex fault scenarios.

[0108] In other aspects of the embodiment of the present invention, after step 600, the following steps are further included:

[0109] Step 700: Control the IoT terminal to perform island detection on the grid connection points in the distribution network;

[0110] Step 800: When it is determined that the island detection does not include an island range, the output frequency of the energy storage device is controlled to be consistent with the frequency of the main grid through the IoT terminal;

[0111] Step 900: When the voltage of the grid-connected point is within a set normal voltage range, control the Internet of Things terminal to send a closing instruction to the grid-connected switch to merge the island range with the main grid in the distribution network.

[0112] Control the IoT terminal to perform island detection on the grid connection points in the distribution network. Here, the grid connection points in the distribution network can be detected for islanding based on the same method as step 100, combined with the passive detection method and the active detection method. Then, through pre-synchronization control, the IoT terminal adjusts the inverter output frequency of the energy storage device to make it consistent with the main grid frequency. Check whether the voltage of the grid connection point is within the set normal voltage range (for example, within the nominal voltage ±5% range, the 220V power grid allows 199V~231V). When the voltage is normal, control the IoT terminal to send a closing command to the grid connection switch to achieve grid connection within the island range. Retry the connection when the voltage is abnormal (the delay or number limit can be increased).

[0113] This embodiment of the present invention is based on a collaborative self-healing system consisting of a "cloud master station + IoT-enabled terminal + grid-connected switch + energy storage device." Using 5G communications, it implements photovoltaic power monitoring, dynamic energy storage regulation, and rapid fault response, addressing grid stability issues under high-penetration photovoltaic access and improving substation energy efficiency and user power supply reliability. Through a closed-loop architecture of "fast terminal perception - grid-connected switch control isolation - flexible energy storage regulation - cloud-based global optimization," this embodiment of the present invention enables autonomous decision-making throughout the entire process of isolated microgrids, from fault isolation to power restoration. This provides a highly reliable and flexible solution for smart distribution networks with a high proportion of renewable energy access.

[0114] Device embodiment

[0115] Please refer to Figure 3 On the other hand, an embodiment of the present invention further provides a distribution network fault processing device, comprising:

[0116] The first island detection module 301 controls the IoT terminal to perform island detection on the grid connection point in the distribution network;

[0117] The first isolation module 302 controls the IoT terminal to send a tripping instruction to the grid-connected switch to isolate the island range from the main grid in the distribution network when the island detection result indicates that an island range exists;

[0118] The balancing control module 303 controls the network device to send a charging instruction or a discharging instruction to the energy storage device through the IoT terminal based on at least the battery charge state of the distributed power supply within the island range, so as to achieve power balance within the island range.

[0119] Optionally, the control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, including:

[0120] The control network device sends a discharge instruction to the energy storage device through the Internet of Things terminal when the state of charge of the battery of the distributed power supply is less than a first set state of charge threshold.

[0121] Optionally, the control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, including:

[0122] The control network device sends a charging instruction to the energy storage device through the Internet of Things terminal when the generated power of the distributed power source is greater than the load power within the island range and the battery state of charge of the distributed power source is less than a second set state of charge threshold.

[0123] Optionally, the device further includes:

[0124] An identification module is used to control the IoT terminal to analyze abnormal data within the island range and identify the fault area;

[0125] The second isolation module is used to control the Internet of Things terminal to send a tripping instruction to the grid-connected switch to isolate the fault area within the island range.

[0126] Optionally, the device further includes:

[0127] An allocation module is used to redistribute the load power supply within the island range based on the predicted output power of the distributed power supply within the island range, the output power of the energy storage device within the island range, and the load priority within the island range; the load priority within the island range includes the priority of the historical load of the fault area and the priority of the load in the non-fault area within the island range except the fault area.

[0128] Optionally, the redistribution of load power supply within the island range based on the predicted output power of the distributed power sources within the island range, the output power of the energy storage device within the island range, and the load priority within the island range includes:

[0129] When the priority of the load in the non-fault area is higher than the priority of the historical load in the fault area, the control network device sends a closing instruction to the grid-connected switch through the Internet of Things terminal, so that at least one of the predicted output power of the distributed power supply in the island range, the output power of the energy storage device in the island range and the power supply power of the main grid can supply power to the load in the non-fault area; and the backup power supply is controlled to supply power to the fault area through the Internet of Things terminal.

[0130] Optionally, during peak electricity price periods, the IoT terminal is used to control the energy storage device to supply power to the loads in the non-fault area; during low electricity price periods, the IoT terminal is used to control partial load operation in the fault area.

[0131] Optionally, the device further includes:

[0132] The second island detection module is used to control the IoT terminal to perform island detection on the grid connection points in the distribution network;

[0133] A frequency control module, configured to control the output frequency of the energy storage device to be consistent with the frequency of the main grid through an IoT terminal when it is determined that the islanding detection does not result in an islanding range;

[0134] The grid-connected module is used to control the Internet of Things terminal to send a closing instruction to the grid-connected switch when the voltage of the grid-connected point is within the set normal voltage range, so as to merge the island range with the main grid in the distribution network.

[0135] Optionally, the controlling the IoT terminal to perform island detection on a grid connection point in the distribution network includes:

[0136] Control the Internet of Things terminal to perform the first island detection on the grid connection point in the distribution network using a passive detection method;

[0137] When the detection result of the first island detection shows that an island range exists, a primary alarm is triggered;

[0138] When a primary alarm is triggered, the IoT terminal is controlled to perform a second island detection on the grid connection point in the distribution network using an active detection method;

[0139] Among them, when the detection result of the second island detection shows that an island range exists, the island detection result is determined to be that an island range exists; when the detection result of the second island detection shows that no island range exists, the island detection result is determined to be that no island range exists.

[0140] Optionally, the passive detection method includes any one of a voltage / frequency threshold detection method, a phase mutation detection method, and a harmonic distortion rate detection method; the active detection method includes any one of an active frequency offset method, a sliding mode frequency drift method, and a reactive power disturbance method.

[0141] The distribution network fault processing device includes a processor and a memory. The above-mentioned first island detection module 301, first isolation module 302, balance control module 303, etc. are all stored in the memory as program units, and the processor executes the above-mentioned program units stored in the memory to realize corresponding functions.

[0142] The processor includes a kernel, which calls the corresponding program unit from the memory. There can be one or more kernels.

[0143] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0144] On the other hand, please refer to Figure 4 , an embodiment of the present invention further provides a distribution network fault handling system, comprising:

[0145] A network device (the embodiment of the present invention is described using the cloud master station 10 as an example), configured to send a charging instruction or a discharging instruction to the energy storage device 40 via the IoT terminal 20 based on at least the battery charge state of the distributed power supply within the island range;

[0146] The Internet of Things terminal 20 is used to perform island detection on the grid connection point in the distribution network; and when it is determined that the island detection result indicates that an island range exists, send a trip command to the grid connection switch 30;

[0147] A grid-connected switch 30, configured to isolate the island range from the main grid in the distribution network in response to the opening instruction;

[0148] The energy storage device 40 is configured to perform charging processing in response to the charging instruction or to perform discharging processing in response to the discharging instruction, so as to achieve power balance within the island range.

[0149] Among them, the cloud master station 10 (cloud-based decision-making layer) serves as the hub of the distribution network fault handling system, responsible for data processing, policy formulation, and remote monitoring; it executes rigid / flexible control instructions issued by the cloud master station 10. The IoT terminal 20 (edge sensing and control layer) monitors the voltage, frequency, phase, power, and waveform distortion rate of the grid connection point in real time; it uses a fusion algorithm analysis method to determine the operating status; it executes the rigid / flexible control instructions issued by the cloud master station 10, completing islanding detection, energy storage charging and discharging control, and preliminary fault isolation. The grid-connected switch 30 (fast execution layer) supports 10ms switching between grid-connected and islanding modes, controls the connection and disconnection of the microgrid to the main grid, realizes photovoltaic access / isolation, energy storage charging and discharging, and load power supply, and ensures the safe and stable operation of the system.

[0150] The IoT terminal 20 is also used to analyze the abnormal data of the island range and identify the fault area; send a tripping instruction to the grid-connected switch 30 to isolate the fault area in the island range. Control the IoT terminal 20 to perform island detection on the grid-connected point in the distribution network. The IoT terminal 20 is also used to control the output frequency of the energy storage device 40 to be consistent with the frequency of the main grid when it is determined that the island detection does not exist in the island range; send a closing instruction to the grid-connected switch 30 when the voltage at the grid-connected point is within the set normal voltage range to merge the island range with the main grid in the distribution network.

[0151] The cloud master station 10 is also used to redistribute the load power supply within the island range based on the predicted output power of the distributed power source within the island range, the output power of the energy storage device 40 within the island range, and the load priority within the island range; the load priority within the island range includes the priority of the historical load of the fault area and the priority of the load in the non-fault area within the island range except the fault area.

[0152] This embodiment of the present invention is based on a collaborative self-healing system consisting of a "cloud master station 10 + IoT-enabled terminals 20 + grid-connected switches 30 + energy storage devices 40." Using 5G communications, it implements photovoltaic power monitoring, dynamic energy storage regulation, and rapid fault response. This addresses grid stability issues associated with high-penetration photovoltaic access, improving substation energy efficiency and user power supply reliability. Through a closed-loop architecture encompassing rapid terminal sensing, grid-connected switch 30 control isolation, flexible energy storage regulation, and cloud-based global optimization, this embodiment enables autonomous decision-making throughout the entire process of isolated microgrids, from fault isolation to power restoration. This provides a highly reliable and resilient solution for smart distribution networks with a high proportion of renewable energy access.

[0153] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a machine-readable storage medium. When the computer program is executed by a processor, the computer can execute a distribution network fault handling method, which includes: controlling an Internet of Things terminal to perform island detection on a grid-connected point in the distribution network; when it is determined that the island detection result is that an island range exists, controlling the Internet of Things terminal to send a tripping instruction to a grid-connected switch to isolate the island range from the main grid in the distribution network; controlling a network device to send a charging instruction or a discharging instruction to an energy storage device through the Internet of Things terminal based at least on the battery charge state of a distributed power source within the island range to achieve power balance within the island range.

[0154] On the other hand, the present invention also provides a machine-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute a distribution network fault handling method, the method comprising: controlling an Internet of Things terminal to perform island detection on a grid-connected point in the distribution network; when it is determined that the result of the island detection is that an island range exists, controlling the Internet of Things terminal to send a tripping instruction to a grid-connected switch to isolate the island range from the main grid in the distribution network; controlling a network device to send a charging instruction or a discharging instruction to an energy storage device through the Internet of Things terminal based at least on the battery charge state of a distributed power source within the island range to achieve power balance within the island range.

[0155] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0156] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0157] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for handling distribution network faults, characterized in that: include: Control the IoT terminal to perform island detection on the grid connection points in the distribution network; When it is determined that the island detection result shows that an island range exists, controlling the Internet of Things terminal to send a tripping instruction to the grid-connected switch to isolate the island range from the main grid in the distribution network; The control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, so as to achieve power balance within the island range.

2. The method for handling distribution network faults according to claim 1, wherein: The control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, including: The control network device sends a discharge instruction to the energy storage device through the Internet of Things terminal when the state of charge of the battery of the distributed power supply is less than a first set state of charge threshold.

3. The method for handling distribution network faults according to claim 1, wherein: The control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, including: The control network device sends a charging instruction to the energy storage device through the Internet of Things terminal when the generated power of the distributed power source is greater than the load power within the island range and the battery state of charge of the distributed power source is less than a second set state of charge threshold.

4. The method for handling distribution network faults according to claim 1, wherein: After determining that the island detection result indicates that an island range exists, controlling the IoT terminal to send a tripping instruction to the grid-connected switch, the method further includes: The control Internet of Things terminal analyzes abnormal data within the island range to identify the fault area; The Internet of Things terminal is controlled to send a tripping instruction to the grid-connected switch to isolate the fault area within the island range.

5. The method for handling distribution network faults according to claim 4, wherein: The method further comprises: Based on the predicted output power of the distributed power supply in the island range, the output power of the energy storage device in the island range and the load priority in the island range, the load power supply in the island range is redistributed; the load priority in the island range includes the priority of the historical load in the fault area and the priority of the load in the non-fault area in the island range except the fault area.

6. The method for handling distribution network faults according to claim 5, characterized in that: The redistribution of power supply to loads within the island range based on the predicted output power of the distributed power sources within the island range, the output power of the energy storage device within the island range, and the load priority within the island range includes: When the priority of the load in the non-fault area is higher than the priority of the historical load in the fault area, the control network device sends a closing instruction to the grid-connected switch through the Internet of Things terminal, so that at least one of the predicted output power of the distributed power supply in the island range, the output power of the energy storage device in the island range and the power supply power of the main grid can supply power to the load in the non-fault area; and the backup power supply is controlled to supply power to the fault area through the Internet of Things terminal.

7. The method for handling distribution network faults according to claim 6, wherein: During peak electricity price periods, the IoT terminal is used to control the energy storage device to supply power to the loads in the non-fault area; during low electricity price periods, the IoT terminal is used to control partial load operation in the fault area.

8. The method for handling distribution network faults according to claim 1, wherein: The method further comprises: Control the IoT terminal to perform island detection on the grid connection points in the distribution network; When it is determined that the islanding detection does not result in an islanding range, controlling the output frequency of the energy storage device to be consistent with the frequency of the main grid through the Internet of Things terminal; When the voltage of the grid-connected point is within the set normal voltage range, the Internet of Things terminal is controlled to send a closing instruction to the grid-connected switch to merge the island range with the main grid in the distribution network.

9. The method for handling distribution network faults according to any one of claims 1 to 8, characterized in that: The controlling Internet of Things terminal to perform island detection on the grid connection point in the distribution network includes: Control the Internet of Things terminal to perform the first island detection on the grid connection point in the distribution network using a passive detection method; When the detection result of the first island detection shows that an island range exists, a primary alarm is triggered; When a primary alarm is triggered, the IoT terminal is controlled to perform a second island detection on the grid connection point in the distribution network using an active detection method; Among them, when the detection result of the second island detection shows that an island range exists, the island detection result is determined to be that an island range exists; when the detection result of the second island detection shows that no island range exists, the island detection result is determined to be that no island range exists.

10. The method for handling distribution network faults according to claim 9, characterized in that: The passive detection method includes any one of a voltage / frequency threshold detection method, a phase mutation detection method, and a harmonic distortion rate detection method; the active detection method includes any one of an active frequency offset method, a sliding mode frequency drift method, and a reactive power disturbance method.

11. A distribution network fault handling device, characterized in that: include: The first island detection module controls the IoT terminal to perform island detection on the grid connection points in the distribution network; a first isolation module, which controls the IoT terminal to send a tripping instruction to the grid-connected switch when determining that the island detection result indicates that an island range exists, so as to isolate the island range from the main grid in the distribution network; A balancing control module controls the network device to send a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, so as to achieve power balance within the island range.

12. The distribution network fault handling device according to claim 11, characterized in that: The control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, including: The control network device sends a discharge instruction to the energy storage device through the Internet of Things terminal when the state of charge of the battery of the distributed power supply is less than a first set state of charge threshold.

13. The distribution network fault handling device according to claim 11, characterized in that: The control network device sends a charging instruction or a discharging instruction to the energy storage device through the Internet of Things terminal based on at least the battery charge state of the distributed power supply within the island range, including: The control network device sends a charging instruction to the energy storage device through the Internet of Things terminal when the generated power of the distributed power source is greater than the load power within the island range and the battery state of charge of the distributed power source is less than a second set state of charge threshold.

14. The distribution network fault processing device according to claim 11, characterized in that: The device further comprises: An identification module is used to control the IoT terminal to analyze abnormal data within the island range and identify the fault area; The second isolation module is used to control the Internet of Things terminal to send a tripping instruction to the grid-connected switch to isolate the fault area within the island range.

15. The distribution network fault processing device according to claim 14, characterized in that: The device further comprises: An allocation module is used to redistribute the load power supply within the island range based on the predicted output power of the distributed power supply within the island range, the output power of the energy storage device within the island range, and the load priority within the island range; the load priority within the island range includes the priority of the historical load of the fault area and the priority of the load in the non-fault area within the island range except the fault area.

16. The distribution network fault processing device according to claim 15, characterized in that: The redistribution of power supply to loads within the island range based on the predicted output power of the distributed power sources within the island range, the output power of the energy storage device within the island range, and the load priority within the island range includes: When the priority of the load in the non-fault area is higher than the priority of the historical load in the fault area, the control network device sends a closing instruction to the grid-connected switch through the Internet of Things terminal, so that at least one of the predicted output power of the distributed power supply in the island range, the output power of the energy storage device in the island range and the power supply power of the main grid can supply power to the load in the non-fault area; and the backup power supply is controlled to supply power to the fault area through the Internet of Things terminal.

17. The distribution network fault handling device according to claim 16, characterized in that: During peak electricity price periods, the IoT terminal is used to control the energy storage device to supply power to the loads in the non-fault area; during low electricity price periods, the IoT terminal is used to control partial load operation in the fault area.

18. The distribution network fault handling device according to claim 11, characterized in that: The device further comprises: The second island detection module is used to control the IoT terminal to perform island detection on the grid connection points in the distribution network; A frequency control module, configured to control the output frequency of the energy storage device to be consistent with the frequency of the main grid through an IoT terminal when it is determined that the islanding detection does not result in an islanding range; The grid-connected module is used to control the Internet of Things terminal to send a closing instruction to the grid-connected switch when the voltage of the grid-connected point is within the set normal voltage range, so as to merge the island range with the main grid in the distribution network.

19. A distribution network fault handling system, comprising: IoT terminals are used to detect islanding at connection points in the distribution network; And when it is determined that the island detection result shows that an island range exists, a tripping instruction is sent to the grid-connected switch; A grid-connected switch, configured to isolate the island range from the main grid in the distribution network in response to the opening instruction; A network device, configured to send a charging instruction or a discharging instruction to the energy storage device via the IoT terminal based on at least the battery charge state of the distributed power supply within the island; An energy storage device is configured to perform charging processing in response to the charging instruction or to perform discharging processing in response to the discharging instruction, so as to achieve power balance within the island range.

20. A machine-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the distribution network fault processing method according to any one of claims 1 to 10 is implemented.

21. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the distribution network fault processing method according to any one of claims 1 to 10 is implemented.

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