Distribution protection method, device, computer equipment and storage medium for low-voltage power distribution area

Abstract

The present application relates to a power distribution protection method, device, computer equipment and storage medium for a low-voltage power distribution area. The method includes: when a leakage protector detects a current residual current, determining the current type based on the change of the current residual current; when the current type is a slowly changing residual current, controlling the leakage protector to trip; when the current type is a suddenly changing residual current, if no blocking signal is detected, controlling the leakage protector to trip after delaying for a first preset time, and controlling the leakage protector to reclose after delaying for a second preset time. By judging the type of the current residual current, the present application can distinguish the reason for the generation of the residual current by the leakage protector, and timely restore power without threatening the personal safety of electric shock, thereby improving the timeliness of power restoration.

Description

Technical Field

[0001] This application relates to the technical field of power distribution, and particularly to a power distribution protection method, device, computer device, and storage medium for a low-voltage power distribution area. Background Art

[0002] Low-voltage power distribution areas are located at the end of the power distribution network. They are widely distributed and large in number, but have poor infrastructure, complex electricity consumption situations, and relatively weak management. These factors lead to frequent power outages in the power distribution areas, and the power restoration work is not only costly but also lacks timeliness. Summary of the Invention

[0003] Based on this, it is necessary to provide a power distribution protection method, device, computer device, and storage medium for a low-voltage power distribution area with high timeliness in view of the above technical problems.

[0004] In a first aspect, this application provides a power distribution protection method for a low-voltage power distribution area. The method includes: when a leakage protector detects a current residual current, determining a current type based on the change situation of the current residual current; wherein the current type includes: slow-changing residual current and sudden-changing residual current; when the current type is the slow-changing residual current, controlling the leakage protector to trip; when the current type is the sudden-changing residual current, if no blocking signal is detected, controlling the leakage protector to trip after a first preset time delay, and controlling the leakage protector to reclose after a second preset time delay.

[0005] In one embodiment, after the step of when the current type is the sudden-changing residual current, the method further includes: if a mutation of the current residual current is detected within the first preset time, controlling the leakage protector to block and trip.

[0006] In one embodiment, the method further includes: obtaining the unbalanced current and phase current of a low-voltage magnetic control circuit breaker; controlling the low-voltage magnetic control circuit breaker based on the change situations of the unbalanced current and the phase current.

[0007] In one embodiment, the step of controlling the low-voltage magnetic control circuit breaker based on the change situations of the unbalanced current and the phase current includes: if both the unbalanced current and the phase current are sudden-changing currents, controlling the low-voltage magnetic control circuit breaker based on the change situation of the phase current.

[0008] In one embodiment, the step of controlling the low-voltage magnetically controlled circuit breaker based on the change of the phase current includes: if the change of the phase current conforms to a first preset change characteristic, controlling the low-voltage magnetically controlled circuit breaker not to trip; wherein, the first preset change characteristic is the change characteristic of the phase current during lightning strike or load switching; if the change of the phase current conforms to a second preset change characteristic, controlling the low-voltage magnetically controlled circuit breaker to trip and reclosing after a third preset time delay; wherein, the second preset change characteristic is the change characteristic of the phase current during electric shock or grounding.

[0009] In one embodiment, after the step of when the residual current protector detects the current residual current, the method further includes: obtaining line state information and current environment information; wherein, the line state information includes: line load, three-phase unbalance condition, line operation duration, and the current environment information includes: temperature and humidity information; determining the cause of line abnormality based on the line state information and the current environment information.

[0010] In one embodiment, after the step of when the residual current protector detects the current residual current, the method further includes: obtaining historical current data; wherein, the historical current data includes: multiple residual currents detected by the residual current protector; determining the current fault type based on the historical current data and the current residual current; performing state adjustment on the residual current protector based on the current fault type; wherein, the state adjustment includes: adjusting the residual current protection setting value, alarm delay tripping control, or controlling the residual current protector to close.

[0011] In a second aspect, the present application further provides a power distribution protection device for a low-voltage power distribution area. The device includes: a type determination module, configured to determine the current type based on the change of the current residual current when the residual current protector detects the current residual current; wherein, the current type includes: slowly changing residual current and suddenly changing residual current; a residual current protection control module, configured to control the residual current protector to trip when the current type is the slowly changing residual current; when the current type is the suddenly changing residual current, if no blocking signal is detected, controlling the residual current protector to trip after a first preset time delay and controlling the residual current protector to reclose after a second preset time delay.

[0012] In a third aspect, the present application further provides a computer device. The computer device includes a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the steps of the above method are implemented.

[0013] Fourthly, the present application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0014] For the above-mentioned power distribution protection method, device, computer equipment and storage medium in the low-voltage power distribution area, when the residual current protector detects the current residual current, the current type is determined according to the change of the current residual current, and the residual current protector is controlled to trip or reclose after a time-delay trip. By judging the type of the current residual current, the reason for the generation of the residual current by the residual current protector can be distinguished, and power can be restored in a timely manner without threatening the personal safety of electric shock, thereby improving the timeliness of power restoration. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic flow chart of the power distribution protection method in an embodiment;

[0016] Figure 2 It is a schematic structural diagram of the three-level protection in an embodiment;

[0017] Figure 3 It is a schematic flow chart of the power distribution protection method in another embodiment;

[0018] Figure 4 It is a schematic structural diagram of the phase current detection in an embodiment;

[0019] Figure 5 It is a schematic flow chart of the power distribution protection method in yet another embodiment;

[0020] Figure 6 It is a schematic flow chart of the power distribution protection method in still another embodiment;

[0021] Figure 7 It is a schematic module diagram of the power distribution protection device in an embodiment;

[0022] Figure 8 It is an internal structure diagram of the computer equipment in an embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0024] As described in the background art, power outages frequently occur in low-voltage power distribution areas. The frequent power outages are mainly due to the tripping of the distribution transformer outgoing line caused by user faults in the rural power grid, suburban areas, and cable overhead radiation under the TT wiring method. Among them, the main reasons include: leakage current generated in the low-voltage transmission line of the power distribution area (the overhead line is too low and the distance from the building does not meet the requirements; the fixing part of the pole guy wire is unreasonable, the process is poor, and there is no isolation insulator; the insulation of the pole, service / lead-out wire is aged or damaged, the wire is broken-stranded, the wire is broken, or the pole falls down, etc.); leakage current generated by household electric motor equipment (the quality of the electrical appliances is poor, such as: most of the leakage current is caused by the poor insulation of unqualified submersible pumps and is not easy to solve; when a large-power single-phase device at the end starts, when the load is three-phase unbalanced, the change in leakage current is detected).

[0025] In the related art, a leakage protection device is set to protect the safety of electricity use. For the leakage protection device, the residual current mainly includes the following two parts: the leakage current generated by the imbalance of the three-phase capacitance to the ground and the ground conductance parameters (static and with little influence), and the leakage current generated by the imbalance of the three-phase line voltage caused by reasons such as three-phase load imbalance (dynamic and with greater influence); the fault current of single-phase grounding, and the current injected into the ground at the grounding point. However, the leakage protection device generally adopts the residual current identification method of "residual current amplitude comparison + time-delay tripping", which cannot avoid the overlimit of the residual current caused by three-phase imbalance, slow insulation aging, weather and meteorological changes, the quality of electrical equipment, and poor insulation. Therefore, it will still cause frequent power outages in the low-voltage power distribution area, and there is a lack of timeliness when restoring power.

[0026] Based on this, the present application proposes a power distribution protection method, device, computer device, and storage medium for a low-voltage power distribution area to solve at least one of the above technical problems.

[0027] In one embodiment, as Figure 1 shown, a power distribution protection method for a low-voltage power distribution area is provided. Taking the application of this method to a power distribution control system as an example, it includes the following steps:

[0028] Step S110, when the leakage protector detects the current residual current, determine the current type based on the change of the current residual current.

[0029] Specifically, as Figure 2 shown, the leakage protector can be the leakage protector set under the three-level protection in the figure, that is, it can be the leakage protector for the total protection, branch line protection, and final protection. The leakage protector real-time monitors the current residual current in the circuit through the built-in detection device and takes it as the current residual current. The residual current refers to the current whose vector sum of the currents of each phase (including the neutral line) in the low-voltage distribution line is not zero. When there is a leakage in the line, the insulation of the equipment is damaged, etc., a residual current will be generated.

[0030] When the residual current protector detects the current residual current, it indicates that a fault has occurred in the corresponding circuit. At this time, by analyzing the change of the current residual current, the current type of the current residual current is determined. The change of the current residual current is the speed of change of the magnitude of the residual current over a period of time. Correspondingly,

[0031] The current types include: slow-changing residual current and sudden-changing residual current.

[0032] Step S120, when the current type is slow-changing residual current, control the residual current protector to trip.

[0033] Specifically, when the current type is slow-changing residual current, it indicates that the current residual current changes gradually and relatively smoothly. Such changes are usually caused by natural factors such as weather or slow aging of lines and equipment. For example, in humid weather, the insulation performance of the line gradually decreases, resulting in a slow increase in the residual current; or when the line operates for a long time, the insulation layer gradually ages, which will also cause the residual current to show a slow change trend. When it is determined that the current type is slow-changing residual current, it indicates that there are certain potential safety hazards in the line or equipment. Although the fault develops relatively slowly, if not dealt with in time, it may gradually deteriorate and eventually lead to more serious safety accidents. For example, if the line is in a humid environment for a long time, the insulation performance continues to decline, and the residual current keeps increasing, which may cause dangerous situations such as electrical fires. Therefore, to ensure safety, the residual current protector will be controlled to trip immediately to cut off the circuit, thereby preventing the further development of the fault and ensuring the safety of personnel and equipment.

[0034] Step S130, when the current type is sudden-changing residual current, if no blocking signal is detected, control the residual current protector to trip after delaying for the first preset time, and control the residual current protector to reclose after delaying for the second preset time.

[0035] Specifically, when the current type is sudden residual current, it indicates that the residual current will increase rapidly within a very short period of time. Such changes are usually caused by sudden faults, such as sudden electric shock to personnel, instantaneous grounding of the line, etc. When the current type is sudden residual current, the leakage protector will first detect whether there is a blocking signal. The blocking signal is sent after the upper-level protection device operates to cut off the fault, and is used to prevent unnecessary repeated tripping of the lower-level protection device. If the blocking signal is not detected, it indicates that the fault may not have been completely handled by the upper level or the fault only occurred within the monitoring range of this level. At this time, to ensure safety, the leakage protector will control a trip after delaying for the first preset time. By delaying for the first preset time, it can ensure more accurate fault judgment and avoid misjudging a trip due to short-term interference. After tripping to cut off the circuit, in order to restore power supply as soon as possible and reduce the impact of power outage on users, the leakage protector will be controlled to reclose after delaying for the second preset time. The setting of the second preset time is to provide a certain time for fault handling and equipment recovery to ensure that the fault has been eliminated or the danger has been lifted. It can be understood that, to ensure the personal safety of the electric shock victim, the time for tripping and reclosing after electric shock, that is, the second preset time, is the minimum time (such as 1 second) for the person to get rid of the central electric shock scenario.

[0036] The above-mentioned distribution protection method for the low-voltage substation area determines the current type according to the change of the current residual current when the leakage protector detects the current residual current, and controls the leakage protector to trip or reclose after a delayed trip according to the current type. By judging the type of the current residual current, the reason for the generation of the residual current by the leakage protector can be distinguished, and power can be restored in a timely manner without threatening the personal safety of the electric shock victim, improving the timeliness of power restoration.

[0037] In one embodiment, in step S130, after the step when the current type is sudden residual current, the distribution protection method further includes: if a mutation of the current residual current is detected within the first preset time, control the leakage protector to block the trip.

[0038] Specifically, when it is determined that the current type is sudden residual current, continue to monitor whether the current residual current mutates again within the first preset time. If the current residual current mutates again within the first preset time, it indicates that the upper-level protection device has detected a fault and operated to cut off the faulty line. Therefore, the residual current in the faulty line will change, and this change can be detected by the leakage protector of the lower-level protection device. If the lower-level protection device does not block the trip at this time, it will cause unnecessary overstep tripping and expand the power outage range. For example, assume that a branch line has a grounding fault, and the upper-level branch line protection device quickly operates to cut off the branch line. At this time, the residual current in the faulty line will suddenly change. If the leakage protector of the lower-level protection on this branch line does not block the trip, it will cause power outage for users who should not have a power outage.

[0039] In one embodiment, as Figure 3 shown, the distribution protection method for the low-voltage power distribution area further includes the following steps:

[0040] Step S210, obtaining the unbalanced current and phase current of the low-voltage magnetic control circuit breaker.

[0041] Specifically, as Figure 4 shown, in the circuit system of the low-voltage power distribution area, the unbalanced current and phase current of the low-voltage magnetic control circuit breaker are obtained through measuring devices such as current transformers (CTs). For the phase current, the current values of the three phases A, B, and C can be directly measured from the three-phase line respectively; the unbalanced current can be obtained by calculating the vector sum of the three-phase currents, which reflects the unbalanced degree of the three-phase load and possible abnormal conditions such as leakage.

[0042] Step S220, controlling the low-voltage magnetic control circuit breaker based on the changes in the unbalanced current and phase current.

[0043] Specifically, for different fault scenarios, the changes in the unbalanced current and phase current will be different. By detecting such differences, the current fault can be judged, and then the low-voltage magnetic control circuit breaker can be controlled to perform corresponding actions to protect the power distribution of the circuit system in the low-voltage power distribution area. And when there are no abnormalities in the unbalanced current and phase current, the low-voltage magnetic control circuit breaker is controlled not to operate.

[0044] In one embodiment, in step S220, the step of controlling the low-voltage magnetic control circuit breaker based on the changes in the unbalanced current and phase current includes: if both the unbalanced current and the phase current are sudden change currents, then controlling the low-voltage magnetic control circuit breaker based on the change in the phase current.

[0045] Specifically, if it is judged that both the unbalanced current and the phase current are sudden change currents, that is, when the current magnitude suddenly changes, it indicates that there is an abnormal situation in the circuit. For example, during a lightning strike, the line current will change violently in a short time, resulting in simultaneous mutations of the unbalanced current and the phase current; when a large device starts or stops, due to its large starting current or sudden change in operating state, it will also cause mutations of the unbalanced current and the phase current; when a person gets an electric shock or the line is grounded, the unbalanced current and the phase current will also mutate. At this time, the corresponding faults can be distinguished based on the change in the phase current, and then the state of the low-voltage magnetic control circuit breaker can be controlled.

[0046] In one embodiment, the step of controlling the low-voltage magnetic control circuit breaker based on the change in the phase current includes: if the change in the phase current conforms to the first preset change characteristic, then controlling the low-voltage magnetic control circuit breaker not to trip; where the first preset change characteristic is the change characteristic of the phase current during lightning strikes or load switching.

[0047] Specifically, during normal operation, the phase current has its specific fluctuation range and pattern. During lightning strikes or load switching, the phase current will mutate. During a lightning strike, the powerful lightning impulse will instantaneously change the electromagnetic field in the line, triggering a sudden increase or fluctuation in the phase current. This change is often a short spike pulse. During load switching when large equipment starts or stops, due to the large starting current of the equipment or the sudden change in the operating state, the phase current will also mutate. However, as the equipment enters a stable operating state, the current will gradually return to normal. When both the unbalanced current and the phase current are mutant currents, the phase current will be compared with a pre-set first preset change characteristic to determine whether they match. If the change situation of the phase current conforms to the first preset change characteristic, the low-voltage magnetically controlled circuit breaker is controlled not to trip. This is because although the current change caused by lightning strikes or load switching is relatively intense instantaneously, in most cases, it will not cause persistent severe damage to the line and equipment. If the circuit breaker trips at this time, it will lead to unnecessary power outages and affect the normal power consumption of users.

[0048] In one embodiment, the step of controlling the low-voltage magnetically controlled circuit breaker based on the change situation of the phase current includes: if the change situation of the phase current conforms to the second preset change characteristic, controlling the low-voltage magnetically controlled circuit breaker to trip and reclosing after a third preset time delay; where the second preset change characteristic is the change characteristic of the phase current during electric shock or grounding.

[0049] Specifically, electric shock and grounding faults will cause current leakage, which will not only pose a serious threat to personal safety but may also trigger dangers such as electrical fires. It is necessary to quickly cut off the power supply to ensure safety. During an electric shock, the human body is connected to the circuit to form a current path, causing abnormal changes in the phase current, and both the magnitude and phase of the current will change; when the line is grounded, a large amount of current flows to the ground, which will also cause the phase current to fluctuate greatly and deviate from the normal range. When it is determined that the change situation of the phase current conforms to the second preset change characteristic, the low-voltage magnetically controlled circuit breaker will be immediately controlled to trip to cut off the faulty circuit. At the same time, after tripping, it will be reclosed after the third preset time to provide a certain time for fault troubleshooting and equipment recovery. If the fault is instantaneous, such as when a person accidentally touches an electric shock and quickly breaks away, after this period of time, the system returns to normal and power supply can be restored after reclosing; if the fault still exists, the circuit breaker will detect abnormal current again after reclosing and trip again to avoid the continuous presence of danger. In some embodiments, the third preset time is the minimum time for a person to break away from the central electric shock scenario (such as 1 second).

[0050] In one embodiment, as Figure 5 shown, after the step of detecting the current residual current by the leakage protector in step S110, the power distribution protection method further includes:

[0051] Step S310, obtaining the line status information and the current environmental information.

[0052] Specifically, when the residual current protector detects the current residual current, it indicates that there is an abnormality in the circuit. At this time, the line status information and the current environmental information are obtained again. The line status information includes: line load, three-phase imbalance situation, and line operation duration. The line load can be obtained by installing power monitoring devices on the low-voltage substation lines, such as smart meters, current transformers, etc., to collect the current magnitude in the line in real time, and then calculate the line load according to the voltage and current data. The three-phase imbalance situation can be monitored by the power monitoring device for the magnitude and phase of the three-phase current. The three-phase imbalance will cause additional heating of the line and equipment, reduce the service life of the equipment, and also generate zero-sequence current, increasing the possibility of abnormal residual current. The line operation duration can be obtained by recording the time when the line is put into use. As the operation duration increases, the components of the line gradually age, the insulation performance decreases, the mechanical strength of the wire decreases, and problems such as breakage and fracture are more likely to occur, thereby triggering leakage, short circuit and other faults. The current environmental information includes: temperature and humidity information, which can be obtained by installing temperature and humidity sensors in the substation area. The environmental temperature and humidity have a significant impact on the line. When the humidity is high, the insulation performance of the line insulation material will decrease, and moisture may penetrate into the interior of the insulation layer, reducing its resistance value and causing an increase in leakage current. In a humid environment, a water film is likely to form on the surface of the insulator of the overhead line, making its insulation performance worse. Too high temperature will cause the line conductor to expand, accelerating the aging of the insulation material; too low temperature may make the conductor brittle and easy to break.

[0053] Step S320, determine the cause of the line abnormality based on the line status information and the current environmental information.

[0054] Specifically, after obtaining the line status information and the current environmental information, by comparing with the collected historical data, the cause of the residual current, that is, the cause of the line abnormality (such as severe three-phase imbalance, aging, grounding, etc.) can be determined. At the same time, by analyzing the influence of the weather on each branch line, the insulation performance of the line can be evaluated, and the aging degree of each branch line can be analyzed. For example, if the line load is high for a long time, the three-phase imbalance is serious, and the operation duration is long, then the possibility of accelerated line aging is very high. The insulation layer of the aging line may be damaged, resulting in leakage and causing abnormal residual current. In a humid environment, if an abnormal increase in residual current is detected and the line operation duration is long, it may be that the humidity causes the insulation performance of the line to decrease, resulting in leakage. If the line load is also high at this time, this situation will be further aggravated. When the environmental temperature is too high and the line load is large, it may cause the line temperature to be too high due to poor heat dissipation, accelerating insulation aging, and then triggering a line fault.

[0055] In one embodiment, as Figure 6As shown, after the step in step S110 when the residual current protector detects the current residual current, the power distribution protection method further includes:

[0056] Step S410, obtaining historical current data.

[0057] Specifically, the power distribution control system will record and store the residual current data detected by the residual current protector and use it as historical current data. The historical current data covers the residual current conditions in different time periods and different power consumption scenarios. It includes the tiny residual current fluctuations during normal power consumption and the abnormal residual current records during minor leakage faults. Through long-term accumulation, the historical current data can reflect the change rules and trends of the residual current in this area.

[0058] Step S420, determining the current fault type based on the historical current data and the current residual current.

[0059] Specifically, when determining the current fault type, the amplitude and change trend of the current residual current can be compared and analyzed according to the historical current data to determine the current fault type. For example, if the amplitude of the current residual current far exceeds the historical normal range and is close to or exceeds the residual current amplitude at the time of tripping due to leakage faults in history, it means that a relatively serious leakage fault has occurred; on the contrary, if the amplitude of the current residual current is only slightly higher than the historical normal range, it may be a minor fault caused by slight moisture in the line or mild aging of equipment insulation. If the current residual current shows a continuous upward trend, and similar trends in historical data are often accompanied by aggravated equipment aging or the gradual development of faults, then it can be determined that there may be problems of aggravated equipment aging or deteriorating potential faults currently. If the current residual current suddenly changes significantly, similar to the sudden change of the residual current caused by instantaneous interferences such as lightning strikes and load switching in history, it may be affected by similar external interferences.

[0060] Step S430, adjusting the state of the residual current protector based on the current fault type.

[0061] Specifically, after determining the current fault type, the state of the leakage protector is adjusted again. The state adjustment includes one of the following: adjusting the leakage protection setting value, alarm delay tripping control, and controlling the closing of the leakage protector. For example, if it is determined that the current fault is a minor leakage caused by aging of the line insulation, resulting in a slight excess of the residual current beyond the normal range but not reaching a dangerous level, the leakage protection setting value can be appropriately increased. This can avoid frequent tripping due to minor leakage caused by normal aging of the line and ensure the continuity of power supply. When it is determined that the current fault may pose a potential risk but will not cause a serious threat to personnel and equipment for the time being, alarm delay tripping control is adopted to delay the tripping time and leave time for maintenance personnel to troubleshoot and handle the fault. During the delay period, the change of the residual current is continuously monitored. If the residual current rises sharply or reaches the dangerous threshold, tripping will occur immediately. If it is determined that the current fault has been eliminated, for example, after maintenance personnel repair the line or equipment and determine that the residual current has returned to the normal range based on historical current data and the current residual current, the closing of the leakage protector can be controlled to restore power supply. In some cases, when the residual current is briefly abnormal, which may be caused by momentary interference and the residual current returns to normal after the interference disappears, the closing of the leakage protector can also be automatically controlled to reduce the power outage time and improve the reliability of power supply.

[0062] It should be understood that although the steps in the flowcharts involved in the above-described embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-described embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be executed alternately or in turn with at least a part of other steps or steps in other steps.

[0063] Based on the same inventive concept, an embodiment of the present application also provides a power distribution protection device for implementing the power distribution protection method for a low-voltage power distribution area described above. The implementation solutions provided by this device to solve problems are similar to those described in the above method. Therefore, the specific limitations in one or more embodiments of the power distribution protection device provided below can refer to the limitations on the power distribution protection method in the above text and will not be repeated here.

[0064] In one embodiment, as Figure 7 shown, a power distribution protection device is provided, including: a type determination module 510 and a leakage protection control module 520, where:

[0065] A type determination module 510, configured to determine the current type based on the change of the current residual current when the residual current protector detects the current residual current; wherein, the current types include: slow-changing residual current and sudden-changing residual current;

[0066] A residual current protector control module 520, configured to control the residual current protector to trip when the current type is slow-changing residual current; when the current type is sudden-changing residual current, if no blocking signal is detected, control the residual current protector to trip after delaying for a first preset time, and control the residual current protector to reclose after delaying for a second preset time.

[0067] In one embodiment, the residual current protector control module 520 is further configured to control the residual current protector to block and trip if a sudden change in the current residual current is detected within the first preset time.

[0068] In one embodiment, the power distribution protection device further includes: a circuit breaker control module, configured to obtain the unbalanced current and phase current of the low-voltage magnetic control circuit breaker; and control the low-voltage magnetic control circuit breaker based on the change of the unbalanced current and phase current.

[0069] In one embodiment, the circuit breaker control module is further configured to control the low-voltage magnetic control circuit breaker based on the change of the phase current if both the unbalanced current and the phase current are sudden-change currents.

[0070] In one embodiment, the circuit breaker control module is further configured to control the low-voltage magnetic control circuit breaker not to trip if the change of the phase current conforms to a first preset change characteristic; wherein, the first preset change characteristic is the change characteristic of the phase current during lightning strike or load switching; if the change of the phase current conforms to a second preset change characteristic, control the low-voltage magnetic control circuit breaker to trip and reclose after delaying for a third preset time; wherein, the second preset change characteristic is the change characteristic of the phase current during electric shock or grounding.

[0071] In one embodiment, the power distribution protection device further includes: an abnormality analysis module, configured to obtain the line status information and the current environment information; wherein, the line status information includes: line load, three-phase unbalance condition, line operation duration, and the current environment information includes: temperature and humidity information; and determine the cause of the line abnormality based on the line status information and the current environment information.

[0072] In one embodiment, the power distribution protection device further includes: a status adjustment module, configured to obtain historical current data; wherein, the historical current data includes: multiple residual currents detected by the residual current protector; determine the current fault type based on the historical current data and the current residual current; and perform status adjustment on the residual current protector based on the current fault type; wherein, the status adjustment includes: adjusting the residual current protection value, warning slow trip control, and controlling the residual current protector to close.

[0073] Each module in the above-mentioned power distribution protection device can be implemented in whole or in part by software, hardware, or a combination thereof. Each of the above modules can be embedded in or independent of a processor in a computer device in hardware form, or stored in a memory in the computer device in software form, so that the processor can call and execute the operations corresponding to each of the above modules.

[0074] In one embodiment, a computer device is provided. The computer device can be a terminal, and its internal structure diagram can be as Figure 8 shown. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface, the display unit, and the input device are connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used for exchanging information between the processor and external devices. The communication interface of the computer device is used for communicating with external terminals in a wired or wireless manner. The wireless manner can be implemented through WIFI, a mobile cellular network, NFC (Near Field Communication), or other technologies. The computer program, when executed by the processor, implements a power distribution protection method for a low-voltage power distribution area. The display unit of the computer device is used to form a visually visible picture, which can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer covering the display screen, or a button, a trackball, or a touchpad provided on the outer shell of the computer device, or an external keyboard, touchpad, or mouse, etc.

[0075] Those skilled in the art can understand that Figure 8 the structure shown in

[0076] is only a block diagram of some structures related to the solution of this application, and does not constitute a limitation on the computer device to which the solution of this application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine some components, or have different component arrangements.

[0077] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the processor executes the computer program, the steps in the above method embodiments are implemented.

[0078] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, database, or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memories. Non-volatile memories can include read-only memory (ROM), magnetic tapes, floppy disks, flash memories, optical memories, high-density embedded non-volatile memories, resistive random access memories (ReRAM), magnetoresistive random access memories (MRAM), ferroelectric random access memories (FRAM), phase change memories (PCM), graphene memories, etc. Volatile memories can include random access memory (RAM) or external cache memories, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The databases involved in the embodiments provided in the present application can include at least one of relational databases and non-relational databases. Non-relational databases can include distributed databases based on blockchain, etc., without limitation. The processors involved in the embodiments provided in the present application can be general-purpose processors, central processors, graphics processors, digital signal processors, programmable logics, data processing logics based on quantum computing, etc., without limitation.

[0079] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0080] The above-described embodiments merely represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the patent scope of the present application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all fall within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A power distribution protection method for a low voltage area, characterized in that: The method comprises: When the leakage protector detects the current residual current, the current type is determined based on the change of the current residual current; wherein the current type includes: slowly changing residual current and suddenly changing residual current; When the current type is the slowly varying residual current, controlling the leakage protector to trip; When the current type is the sudden residual current, if no locking signal is detected, the leakage protector is controlled to trip after a first preset delay time, and the leakage protector is controlled to reclose after a second preset delay time; Obtain unbalanced current and phase current of low voltage magnetic circuit breaker; Controlling the low-voltage magnetically controlled circuit breaker based on the changes of the unbalanced current and the phase current comprises: if both the unbalanced current and the phase current are sudden change currents, controlling the low-voltage magnetically controlled circuit breaker based on the changes of the phase current; Wherein, the step of controlling the low-voltage magnetically controlled circuit breaker based on the change of the phase current includes: if the change of the phase current meets the first preset change characteristic, controlling the low-voltage magnetically controlled circuit breaker not to trip; wherein, the first preset change characteristic is the change characteristic of the phase current when lightning strikes or load switching; if the change of the phase current meets the second preset change characteristic, controlling the low-voltage magnetically controlled circuit breaker to trip and overlap after a delay of a third preset time; wherein, the second preset change characteristic is the change characteristic of the phase current when electric shock or grounding occurs; Acquire historical current data; wherein the historical current data includes: a plurality of residual currents detected by the leakage protector; Determine a current fault type based on the historical current data and the current residual current; The state of the leakage protector is adjusted based on the current fault type; wherein the state adjustment includes: adjusting the leakage protector setting value, alarm slow tripping control, and controlling the leakage protector closing.

2. The power distribution protection method for low voltage substations according to claim 1, characterized in that: After the step of when the current type is the sudden residual current, the method further includes: If a sudden change in the current residual current is detected within the first preset time, the leakage protector is controlled to lock and trip.

3. The power distribution protection method for low voltage substations according to claim 1, characterized in that: After the step of detecting the current residual current by the leakage protector, the method further comprises: Acquire line status information and current environment information; wherein the line status information includes: line load, three-phase imbalance, and line operation time, and the current environment information includes: temperature and humidity information; The cause of the line abnormality is determined based on the line status information and the current environment information.

4. A power distribution protection device for a low voltage area, characterized in that: The device is used to execute the power distribution protection method for the low voltage area according to any one of claims 1 to 3, and comprises: A type determination module, used for determining the current type based on the change of the current residual current when the residual current is detected by the leakage protector; wherein the current type includes: slowly changing residual current and suddenly changing residual current; The leakage protection control module is used to control the leakage protector to trip when the current type is the slowly changing residual current; when the current type is the sudden changing residual current, if no locking signal is detected, the leakage protector is controlled to trip after a first preset delay time, and the leakage protector is controlled to reclose after a second preset delay time.

5. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 3 are implemented.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 3 are implemented.

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