Load transfer path analysis method and system based on distribution network switch topology

Abstract

The invention relates to the technical field of intelligent load transfer of a distribution network, in particular to a load transfer path analysis method and system based on distribution network switch topology. The load transfer path analysis method based on the distribution network switch topology comprises the following steps: acquiring an operation signal of an electric appliance in a management distribution network, and calculating to obtain circuit data of the electric appliance; and the real-time temperature of each electric appliance is detected and obtained. And calculating to obtain the risk index of the electric appliance. And judging whether an operation risk exists or not according to the risk index and a standard risk index, and carrying out load transfer by correspondingly setting up an interconnection switch. When the electric appliance breaks down, heat can be generated, and unstable current can be caused, so that the load can be transferred before the electric appliance is damaged, the circuit and the electric appliance are prevented from being damaged, and meanwhile, the loss caused by power failure of the circuit can also be avoided. And the electric appliance with the best stability can be selected for power transfer, so that the safety and the stability of power utilization are ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent load transfer in a distribution network, and particularly to a method and system for analyzing load transfer paths based on a distribution network switch topology. Background Art

[0002] The distribution network switch topology is mainly applied in an electric power distribution system and is used to describe the layout, connection, and operating status of switch devices and subsystems. This topological structure helps to optimize the operation of the power grid, reduce the risk of faults, and improve power supply reliability. In the distribution network switch topology, the main devices involved are: 1. Main transformer: A device that converts high-voltage electrical energy into low-voltage electrical energy, usually located in a substation. 2. Line-side switch: Responsible for controlling and protecting the power flow between the main transformer and users. 3. Distribution transformer: Further distributes the low-voltage electrical energy from the main transformer to each user. 4. Distribution line: A wire system that connects the main transformer, distribution transformers, and various users. 5. Switching equipment: Such as circuit breakers, disconnectors, earthing switches, etc., which are used to control and protect the safe operation of the power system. The main objective of the distribution network switch topology is to achieve the balanced, stable, and reliable operation of the power system. By observing the topology diagram, we can understand the operating status, location, and connection relationship of each device, analyze the power grid load and operating conditions, formulate reasonable operating strategies, optimize resource allocation, reduce the risk of faults, and improve the quality of power supply services. At the same time, the topological structure can also be used as a tool for fault diagnosis to help us quickly locate and solve problems.

[0003] In a power system, load transfer refers to the process of temporarily taking over part of the load from a standby power source or the power grid when the load in the power system changes. This usually occurs when the power supply in the main load center is insufficient, and it is necessary to adjust the load transfer power supply to meet the power demand. Load transfer can be divided into two methods: active and passive: 1. Active load transfer: This transfer method is carried out when the power demand in the load center decreases, mainly to save energy and reduce costs. Active load transfer can be achieved by adjusting the load distribution, that is, transferring power from areas with high power density to areas with low power density. This method requires a certain ability of prediction and real-time monitoring. 2. Passive load transfer: This transfer method is carried out when the power demand in the load center increases, mainly to cope with the power shortage caused by emergencies. Passive load transfer is usually automatically completed without manual intervention. When it is detected that the power demand in a certain area increases, the control center of the power system will automatically initiate corresponding measures, such as turning on the standby power source or absorbing power from the power grid. Load transfer is an important power management strategy, which can effectively utilize and regulate power resources while meeting the power demand.

[0004] However, attention should also be paid to some potential problems in load transfer. These problems are often discovered only after an electrical appliance fails, at which time the electrical appliance or the circuit has already been damaged, resulting in economic losses. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a method for analyzing load transfer paths based on the topology of distribution network switches, which is used to predict faulty electrical appliances and transfer their loads, so as to achieve the safety and normal operation of the circuit. The method for analyzing load transfer paths based on the topology of distribution network switches may include:

[0006] S1. Obtain the operation signals of electrical appliances in the managed distribution network, and obtain the circuit data of each electrical appliance according to the operation signals.

[0007] S2. Detect and obtain the real-time temperature Ti of each electrical appliance i , where i is the number of the electrical appliance in the distribution network.

[0008] S3. Calculate and obtain the risk index Ri of the electrical appliance according to the real-time temperature Ti i and the circuit data. When an electrical appliance fails, it will generate heat and cause current instability. Before these symptoms appear, it generally does not cause damage to the electrical appliance. Therefore, we can judge through this and perform load transfer before the electrical appliance is damaged, which can not only protect the electrical appliance but also ensure the smooth output of the operation. It avoids the losses caused by the damage of electrical appliances and power outages. i

[0009] S4. Judge whether the risk index Ri of the electrical appliance i is greater than a preset standard risk index R0 标 . If so, execute S5; if not, execute S6. The preset standard risk index R0 标 can be set according to experience, and can also be the value detected through a destructive experiment on this electrical appliance. Of course, it can also be replaced by the risk index calculated from the values detected by damaged electrical appliances.

[0010] S5. Determine that the electrical appliance has an operation risk, disconnect the control switch of the electrical appliance, and perform load transfer. When it is repeatedly determined that the electrical appliance has an operation risk but there is no fault after inspection, the preset standard risk index R0 标 can be corrected, and its value can be slightly increased. If it was not determined before the equipment failed, the value of the preset standard risk index R0 标 can be reduced. The specific details are not elaborated here. The preset standard risk index R0 标It can be judged in grades and then processed in grades. The specific content of grade judgment and grade processing will not be elaborated here.

[0011] S6. Determine that there is no operation risk for the electrical appliance, keep the electrical appliance running normally, and then execute S1 to perform cyclic data acquisition and judgment.

[0012] S7. Determine whether the electrical appliance is a circuit function electrical appliance. If it is, execute S8; if not, execute S9. Here, we can divide electrical appliances into function electrical appliances and working electrical appliances. For function electrical appliances, without this electrical appliance, other electrical appliances on the same circuit cannot work properly. For working electrical appliances, skipping this electrical appliance, other electrical appliances on the same circuit can work properly.

[0013] S8. Obtain the optimal load transfer electrical appliance with the same function as the electrical appliance in the distribution network, and use the optimal load transfer electrical appliance as the target electrical appliance to complete the load transfer accordingly. When designing the distribution network circuit, we need to configure control switches on the circuits of each electrical appliance. When all the control switches on the same circuit are closed, the circuit can form a complete closed circuit. If one of the control switches is opened, the electrical appliances on the circuit cannot work. There are connection lines and connection switches corresponding to both ends between function electrical appliances, so two electrical appliances with the same function can be used as backups for each other. When one of the electrical appliances has an operation risk, disconnect the control switch corresponding to this electrical appliance, and connect both ends through the connection line and connection switch to the two ends of the electrical appliance with the same function, so as to facilitate load transfer. Of course, load transfer can also be completed through other methods.

[0014] S9. If the electrical appliance is not a circuit function electrical appliance, it proves that the electrical appliance does not affect the work of other electrical appliances, and we can avoid it through a parallel circuit.

[0015] Preferably, the circuit data may include: rated electric power P i and actual electric power P i ’.

[0016] Preferably, the real-time temperature T i The calculation specifically may include: dividing the influence area of the temperature of the electrical appliance to obtain each internal temperature interference area and sorting them. Calculate the area temperature T i j of the internal temperature interference area of the electrical appliance, and then take the maximum value Max{T i j} of the area temperature of the electrical appliance as the real-time temperature T i, through this calculation method, the maximum value in each internal temperature interference area can be obtained. Due to different working procedures, different aging degrees or damage parts caused by other forms of each electrical appliance, through this method, the temperature area with the largest change can be found, so as to facilitate timely positioning and analysis, and maximize the accuracy of analysis and positioning.

[0017] Preferred: Area temperature where j is the number of the internal temperature interference area of the electrical appliance numbered i, and P i ’ is the actual electric power of the electrical appliance numbered i, and P i is the rated electric power of the electrical appliance numbered i, and the units of both are W. σ is the Stokes constant, and its value is generally 5.67×10 -8 W / m 2 K 4 , ξ is the surface reflectivity, and its value can be obtained by looking up the table according to the material of this internal temperature interference area, and the range is between 0 and 1. φ is the environmental coefficient, and the influence of environmental temperature, humidity and wind speed on it needs to be considered, and it can be obtained according to experience. Its specific value is generally 1-10. For general electrical appliances, the internal temperature interference area is generally sealed, and the value can be 1. ɑ j is the proportion area coefficient of the internal temperature interference area numbered j, and the unit is 1 / m 2 , and its value range is between 0 and 1, and it can be obtained according to experience or experimental detection.

[0018] Preferred: Proportion area coefficient where j is the number of the internal temperature interference area of the electrical appliance numbered i, and J is the total number of the internal temperature interference areas of the electrical appliance numbered i. j = 1,..., J; A i is the total heat dissipation area of the electrical appliance numbered i, and its value is the sum of each internal temperature interference area. At this time, the internal temperature interference area needs to count all non-rated heat generation areas. A i j is the heat dissipation area of the internal temperature interference area numbered j of the electrical appliance numbered i, and these two values can be obtained according to the specific parameters of each electrical appliance and the corresponding internal temperature interference area. ε j is the scattering coefficient of the internal temperature interference area numbered j, and its value is related to the scattering ability of the temperature. The specific value range is 0.1-10, and it can be obtained by conducting experiments on each electrical appliance in advance.

[0019] Preferred: The risk index R i =R T W T +R I W I , where RT is the sub - item index of temperature fluctuation risk, R I is the sub - item index of current fluctuation risk, W T is the sub - item weight coefficient of temperature fluctuation risk, W I is the sub - item weight coefficient of current fluctuation risk.

[0020] Preferably: The calculation method of the sub - item weight coefficient W of temperature fluctuation risk T includes: counting the number N of temperature - fluctuation damages of electrical appliances of the same type damaged within a preset time period T This preset time period can be one year or one quarter, and its statistical scope can include all distribution networks that can detect real - time current and temperature. Then the sub - item weight coefficient of temperature fluctuation risk where N’ is the damage threshold of electrical appliances of this same type within the preset time period, which can be replaced by an average value or a specified value, and Norm() represents the normalization function.

[0021] Preferably: The calculation method of the sub - item weight coefficient W of current fluctuation risk I includes: counting the number N of current - fluctuation damages of electrical appliances of the same type damaged within a preset time period I This preset time period can be one year or one quarter, and its statistical scope can include all distribution networks that can detect real - time current and temperature. Then the sub - item weight coefficient of current fluctuation risk where N’ is the damage threshold of electrical appliances of this same type within the preset time period, which can be replaced by an average value or a specified value, and Norm() represents the normalization function.

[0022] Preferably: The calculation method of the sub - item index R of temperature fluctuation risk T can include the sub - item index of temperature fluctuation risk where T’ is the operating environment temperature of the current electrical appliance.

[0023] Preferably: The calculation method of the sub - item index R of temperature fluctuation risk T can include: calculating the temperature - rise value ΔT = T i - T', where T’ is the operating environment temperature of the current electrical appliance. Then, taking time as the abscissa and temperature as the ordinate to construct a plane coordinate system, and then inserting the temperature - rise values corresponding to each time point into the coordinate system to obtain each coordinate point, and then connecting each coordinate point in chronological order to form a temperature - rise curve, and then calculating the sub - item index of temperature fluctuation risk where m is the order of differentiation of the current time point of the temperature - rise curve, M is the total order of differentiation of the current time point of the temperature - rise curve, m = 1, …, M; k mis the m-th order coefficient at the current time point of the temperature rise curve, k 0 is the curve coefficient, ΔT m is the m-th order derivative at the current time point of the temperature rise curve. By calculating the temperature fluctuation risk sub-index in this way, not only the influence of the current value can be considered, but also the trend of the value development can be considered, which can make a better judgment. The k 0 and k m The specific values of can be obtained according to experience, and specifically, the influence of the trend of each stage of development on the temperature rise value should be considered.

[0024] Preferably: k 0 = 1 / T’, where T’ is the operating environment temperature of the current electrical appliance.

[0025] Preferably: the m-th order coefficient at the current time point of the temperature rise curve where a is the trend influence base number, and its value is greater than 1. Generally, it can be taken as 2. Since the trend change of temperature is slow, generally, the total number of derivative orders M at the current time point of the temperature rise curve is 0 or 1.

[0026] Preferably: the current fluctuation risk sub-index R I The calculation method can also include: calculating the current fluctuation value where U i is the rated voltage of the i-th electrical appliance. Then, taking time as the abscissa and the current fluctuation value as the ordinate, a plane coordinate system is constructed. Then, the current fluctuation values corresponding to each time point are inserted into the coordinate system to obtain each coordinate point. Then, each coordinate point is connected in sequence according to the time order to form a current fluctuation curve. Then, the current fluctuation risk sub-index is calculated where n is the derivative order at the current time point of the current fluctuation curve, N is the total derivative order at the current time point of the current fluctuation curve, n = 1, …, N; k n is the n-th order coefficient at the current time point of the current fluctuation curve, ΔI n is the n-th order derivative at the current time point of the current fluctuation curve. By calculating the current fluctuation risk sub-index in this way, the instantaneous change of the current can be fully calculated, and it can quickly analyze whether the electrical appliance has a fault, providing a data basis for timely judgment and positioning.

[0027] Preferably: the n-th order coefficient at the current time point of the current fluctuation curve where b is the current trend influence base number, and its value is greater than 1. Generally, it can be taken as 2. Of course, other value settings are not excluded. Since the current fluctuation changes greatly at the moment of the fault occurrence, we need to give preference to considering the value of its derivative here. N generally takes the value of 3, and specific details are not elaborated here, I iis the rated current of the electrical appliance numbered i. Through the two-way calculation of temperature and current, the interference of one item can be avoided, and the accuracy of judgment can be improved.

[0028] Preferably: The method for obtaining the optimal load transfer electrical appliance may include: obtaining the real-time current I of the electrical appliances with the same function in the distribution network s , where s is the number of the electrical appliances with the same function, excluding the electrical appliances without operation risks. Then calculate and obtain its operation stability index Q s , and use the electrical appliance with the largest operation stability index Q s as the optimal load transfer electrical appliance to set up the load transfer path.

[0029] Preferably: The operation stability index where R s is the risk index of the electrical appliance with the same function numbered s, P s ’ is the current electric power of the electrical appliance with the same function numbered s, and Us is the rated voltage of the electrical appliance with the same function numbered s. By setting up the load transfer path through this method, the electrical appliance with the best stability can be selected for transfer, so that the circuit after load transfer can be the most stable, ensuring the safety and stability of power consumption, and thus avoiding power supply losses.

[0030] The present invention also proposes a load transfer path analysis system based on the distribution network switch topology, which is used to predict the faulty electrical appliances and transfer their loads. The load transfer path analysis system based on the distribution network switch topology may include:

[0031] Circuit data detection module: used to obtain the operation signals of the electrical appliances in the managed distribution network and obtain the circuit data of each electrical appliance according to the operation signals. The circuit data may include: rated electric power P i and actual electric power P i ’.

[0032] Real-time temperature acquisition module: used to detect and obtain the real-time temperature T of each electrical appliance i , the real-time temperature acquisition module may be a temperature sensing module, and may also calculate and obtain the real-time temperature T through the rated electric power P i and actual electric power P i ’. i .

[0033] Calculation and analysis module, used to calculate and obtain the risk index R of the electrical appliance according to the real-time temperature T i of the electrical appliance and the circuit data i .

[0034] Judgment and analysis module, used to judge the risk index R of the electrical appliance iIs it greater than a preset standard risk index R 标 , if not, it is determined that the electrical appliance has no operation risk, and the electrical appliance is kept operating normally. If so, it is determined that the electrical appliance has an operation risk, the control switch of the electrical appliance is disconnected, and load transfer is performed. It is also determined whether the electrical appliance is a circuit function electrical appliance. If so, the optimal load transfer electrical appliance with the same function as the electrical appliance in the distribution network is obtained, and the optimal load transfer electrical appliance is used as the target electrical appliance to complete the load transfer accordingly. If not, the electrical appliance is not a circuit function electrical appliance, which proves that the electrical appliance does not affect the operation of other electrical appliances, and we can avoid it through a parallel circuit.

[0035] The positioning and alarm module is used for alarming and sending the electrical appliance with operation risk to maintenance personnel.

[0036] Preferably, the load transfer path analysis system based on the distribution network switch topology further includes a correction module for correcting the preset standard risk index R 标 When it is repeatedly determined that the electrical appliance has an operation risk but there is no fault during maintenance, the preset standard risk index R 标 can be corrected, and its value can be slightly increased. If it is not determined before the equipment fails, the value of the preset standard risk index R 标 can be reduced, so that the standard risk index can be updated in time, and the accuracy of the determination can be improved. Details are not described here.

[0037] The technical effects and advantages of the present invention: When an electrical appliance fails, it will generate heat and cause current instability. Before these signs appear, it generally will not cause damage to the electrical appliance. Therefore, through this determination, load transfer can be performed before the electrical appliance is damaged, thus avoiding damage to the circuit and the electrical appliance, and also avoiding losses caused by circuit power outages. Then an alarm can be sent to send the number of the electrical appliance with operation risk to the maintenance personnel, so as to facilitate the maintenance personnel to perform maintenance and troubleshoot faults in a timely manner. When the troubleshooting is completed or it is determined that there is no risk, normal power supply can be resumed. Through the two-way calculation of temperature and current, the interference of one item can be avoided, and the accuracy of the judgment is improved. By using this method to set up the load transfer path, the electrical appliance with the best stability can be selected for transfer, so that the circuit after load transfer is the most stable, ensuring the safety and stability of power consumption, and thus avoiding power supply losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is a schematic flowchart of the load transfer path analysis method based on the distribution network switch topology proposed by the present invention.

[0039] Figure 2 It is a structural block diagram of a load transfer path analysis system based on the distribution network switch topology proposed by the present invention.

[0040] Figure 3 It is a schematic diagram of the calculation process of the real-time temperature in the load transfer path analysis method based on the distribution network switch topology proposed by the present invention.

[0041] Figure 4 It is a schematic diagram of the calculation process of the optimal load transfer electrical appliance in the load transfer path analysis method based on the distribution network switch topology proposed by the present invention. Detailed implementation manners

[0042] The embodiments of the present disclosure will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present disclosure and should not be construed as a limitation of the present disclosure. On the contrary, the embodiments of the present disclosure include all changes, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0043] Embodiment 1

[0044] Refer to Figure 1 , in this embodiment, a load transfer path analysis method based on the distribution network switch topology is proposed, which is used to predict a faulty electrical appliance and transfer its load to achieve the safety and normal operation of the circuit. The load transfer path analysis method based on the distribution network switch topology may include:

[0045] S1. Obtain the operation signals of the electrical appliances in the managed distribution network, and obtain the circuit data of each electrical appliance according to the operation signals; the circuit data may include: the rated electric power P i and the actual electric power P i’, where i is the number of the electrical appliance in the management power grid, and the operation signal can be obtained through the background service center. In the actual working process, each electrical appliance in the power grid will receive the operation instruction sent by the background service center, and then work according to the program of the instruction issued by the operation instruction. Through the operation instruction, the current operation status data of each electrical appliance can be obtained without dispute. Through the current operation status data, the name of the operating electrical appliance, the operating program, and the rated electric power of the operating program can be obtained. As long as we obtain the control signals of each electrical appliance, we can obtain the working programs of those electrical appliances in advance, and through the operating program, we can obtain its rated electric power. When numbering the electrical appliances in the power grid, the number sorting method can be sorted according to its failure rate. Those with a large failure rate are ranked in the front, and those with a small failure rate are ranked in the back. Of course, other sorting methods are not excluded, and specific details are not elaborated here. The management power grid is the circuit composed of all relevant electrical appliances in the power grid. Generally, as a management power grid is fixed, specific details are not elaborated here. The actual electric power P i ’ can be obtained by detection. Of course, detecting the rated current and the actual current can also have the same effect. The detection of current is mainly applied to high-voltage short-circuit protection, motor control, DC / DC converters, system power consumption management, current management of secondary batteries, battery management, etc. Advantages: Simple and direct: Only a small resistor and a voltage measuring device are needed to achieve. Low cost: Current detection resistors and voltage measuring devices are usually inexpensive. Strong real-time performance: It can directly reflect the current change in the circuit. Disadvantages: Limited accuracy: Affected by resistor accuracy and temperature changes. May introduce additional impedance: Especially in low-side current detection, additional impedance may be introduced, affecting the circuit performance. Advantages of electric power detection: Comprehensiveness: It can provide complete information on the energy consumption in the circuit. Applicable to complex circuits: When it is necessary to understand the overall performance of the circuit, electric power detection is more applicable. Disadvantages: Increased complexity: It is necessary to measure voltage and current simultaneously and perform calculations. High cost: More measuring devices and computing resources are required. Generally, it is more common to choose electric power.

[0046] S2. Detect and obtain the real-time temperature T of each electrical appliance i , where i is the number of the electrical appliance in the power grid, and the real-time temperature T iThe detection can be obtained through the temperature sensing module. The specific structure of the temperature sensing module is the prior art and will not be elaborated here. The detection position of the temperature sensing module is not the operation position or the operation object of the electrical appliance, but the component area where faults are most likely to occur or the position where the temperature is most likely to rise, such as the position where its circuit board is located. Generally, after an abnormal phenomenon occurs in an electrical appliance, an abnormal current causes an overload or short circuit of the load, and the electrical equipment may overheat. At this time, the metal shell or other heat dissipation parts of the equipment will emit an abnormal smell, and the operation sound of the equipment may also become unstable, which is a precursor to a fault in the electrical appliance. Generally, the real-time temperature T obtained through detection i , may not necessarily represent the maximum temperature of the electrical appliance. If the circuit board of the electrical appliance has a large area or is relatively complex, installing temperature sensing modules at different positions of each electrical appliance will increase the equipment cost. Refer to Figure 3 , we can also calculate through the rated power consumption and the actual power. Specifically, it can include: dividing the influence area of the electrical appliance temperature to obtain each internal temperature interference area and sorting them. Generally, the influence area can be divided by temperature difference, component tolerance temperature, etc. Specifically, it needs to be obtained according to the range of the circuit board in the electrical appliance, the divided space, and the tolerance temperature of each component. If the structure is simple and the range is small, the internal temperature interference area can be 1. The specific division method is not the protection subject of this application and will not be elaborated here. Then, the area temperature of the internal temperature interference area of the electrical appliance can be calculated where j is the number of the internal temperature interference area of the electrical appliance numbered i, P i ’ is the actual electric power of the electrical appliance numbered i, and P i is the rated electric power of the electrical appliance numbered i. The units of both are watts. σ is the Stokes constant, and its value is generally 5.67×10 -8 W / m 2 K 4 , ξ is the surface reflectivity, and its value can be obtained by looking up the table according to the material of this internal temperature interference area. The range is between 0 and 1. The specific value-taking method is not the protection theme of this application and will not be elaborated here. φ is the environmental coefficient, and the influence of environmental temperature, humidity, and wind speed on it needs to be considered. It can be obtained based on experience. Its specific value is generally 1 - 10. For general electrical appliances, the internal temperature interference area is generally sealed, and the value can be 1. Other situations will not be elaborated here. ɑ j is the area ratio coefficient of the internal temperature interference area numbered j, with the unit of 1 / m 2 , and its value range is between 0 and 1. It can be obtained based on experience or experimental detection. Of course, it can also be obtained through calculation. Specifically, it can be the area ratio coefficient where Ai is the total heat dissipation area of the electrical appliance numbered i, and its value is the sum of each internal temperature interference area. At this time, all non-rated heat generation areas need to be counted for the internal temperature interference area, and the specific details are not elaborated here. A i j is the heat dissipation area of the internal temperature interference area numbered j of the electrical appliance numbered i. These two values can be obtained according to the specific parameters of each electrical appliance and the corresponding internal temperature interference area, and the specific details are not elaborated here. ε j is the scattering coefficient of the internal temperature interference area numbered j, and its value is related to the scattering ability of temperature. The specific value range is 0.1 - 10, and it can be obtained by conducting experiments on each electrical appliance in advance. The specific value-taking method is not the protected subject of this application, and the specific details are not elaborated here. Then, take the maximum value Max{T i j} of the section temperature of the electrical appliance as the real-time temperature T i . By calculating in this way, the maximum value in each internal temperature interference area can be obtained. Due to different working procedures, different aging degrees or damage parts caused by other forms of each electrical appliance, the temperature area with the largest change can be found through this method, so as to facilitate timely positioning and analysis, and maximize the accuracy of analysis and positioning.

[0047] S3. According to the real-time temperature T i and the rated electric power P i , the actual electric power P i ’, calculate to obtain the risk index R i of the electrical appliance. When the electrical appliance fails, it will generate heat and cause current instability. Before these symptoms appear, it generally will not cause damage to the electrical appliance. Therefore, through this judgment, load transfer can be carried out before the electrical appliance is damaged, which can not only protect the electrical appliance but also ensure the smooth output of the operation. It avoids the losses caused by the damage of the electrical appliance and power outage. Of course, the possibility of instantaneous damage to the electrical appliance is not excluded. The calculation method of the risk index R i is various. The risk index R i = R T W T + R I W I , where R T is the temperature fluctuation risk sub-index, R I is the current fluctuation risk sub-index, W T is the temperature fluctuation risk sub-weight coefficient, W I is the current fluctuation risk sub-weight coefficient. The temperature fluctuation risk sub-weight coefficient W T and the current fluctuation risk sub-weight coefficient W IIt can be set according to the sensitivity of electrical appliances to temperature and current fluctuations, and its value is controlled within the range of 0-1. The higher the sensitivity, the larger the value. Specifically, it can be set through experiments or manual assignment. Of course, it can also be obtained through calculation. If obtained through calculation, it can include: counting the same type of damaged electrical appliances within a preset time period, including the number N of current fluctuation damages and temperature fluctuation damages T and N I , this preset time period can be one year or one quarter, and its statistical scope can include all distribution networks that can detect real-time current and temperature. Details are not described here. Then the temperature fluctuation risk sub-item weight coefficient where N’ is the damage threshold of the same type of electrical appliances within the preset time period, which can be replaced by the average value or a specified value. Norm() represents the normalization function. The normalization function is a prior art, and there are various forms of the normalization calculation formula. Commonly used ones are linear normalization and standardization. Linear normalization converts the original data to the range of [0, 1] through the following formula. Standardization normalizes the original data set to a data set with a mean of 0 and a variance of 1 through the following formula. These normalization methods are selected according to actual application requirements and specific data situations, which can improve the effect of data processing and the training effect of the model. Details are not described here. Through this method, we can distinguish between temperature sensitivity and current sensitivity, so as to facilitate quantitative calculation. The calculated values are more accurate and agile, and it is convenient to carry out load transfer in a timely manner. The temperature fluctuation risk sub-item index R T and the current fluctuation risk sub-item index R I can be obtained by the real-time temperature T i of the electrical appliance and the rated electric power P i 、the actual electric power P i ’. The specific calculation method can include the temperature fluctuation risk sub-item index where T’ is the operating environment temperature of the current electrical appliance, and this value can be obtained through weather forecasts or environmental detection. The calculation method of the temperature fluctuation risk sub-item index can also include calculating the temperature rise value ΔT = T i -T', then constructing a plane coordinate system with time as the abscissa and temperature as the ordinate, and then inserting the temperature rise values corresponding to each time point into the coordinate system to obtain each coordinate point, and then connecting each coordinate point in chronological order to form a temperature rise curve, and then calculating the temperature fluctuation risk sub-item index where m is the order of differentiation of the current time point of the temperature rise curve, M is the total order of differentiation of the current time point of the temperature rise curve, m = 1,..., M; k m is the m-order coefficient of the current time point of the temperature rise curve, k 0 is the curve coefficient, ΔTm is the m-th derivative of the current time point of the temperature rise curve. By calculating the temperature fluctuation risk sub-index in this way, not only the influence of the current value can be considered, but also the trend of the value development can be considered, which can make a better judgment. The k 0 and k m The specific values of can be obtained according to experience. Specifically, the influence of the development trend of each stage on the temperature rise value should be considered. Generally, k 0 can be 1 / T’, where a is the base number of the trend influence, and its value is greater than 1. Generally, it can be taken as 2. Of course, other numerical settings are not excluded. Since the trend change of temperature is slow, generally, the value of the total derivative order M of the current time point of the temperature rise curve is 0 or 1. Of course, other numerical settings are not excluded, and specific details are not elaborated here. The current fluctuation risk sub-index R I The calculation method can also include: calculating the current fluctuation value where U i is the rated voltage of the electrical appliance numbered i. Then, taking time as the abscissa and the current fluctuation value as the ordinate, a plane coordinate system is constructed. Then, the current fluctuation values corresponding to each time point are inserted into the coordinate system to obtain each coordinate point. Then, each coordinate point is connected in sequence according to the time order to form a current fluctuation curve. Then, the current fluctuation risk sub-index is calculated where n is the derivative order of the current time point of the current fluctuation curve, N is the total derivative order of the current time point of the current fluctuation curve, n = 1,..., N; k n is the n-th coefficient of the current time point of the current fluctuation curve, ΔI n is the n-th derivative of the current time point of the current fluctuation curve. By calculating the current fluctuation risk sub-index in this way, the instantaneous change of the current can be fully calculated, and it can quickly analyze whether the electrical appliance has a fault, providing a data basis for timely judgment and positioning. k n The specific value of can be obtained according to experience. Specifically, the influence of the development trend of each stage on the current fluctuation value should be considered where b is the base number of the current trend influence, and its value is greater than 1. Generally, it can be taken as 2. Of course, other numerical settings are not excluded. Since the current fluctuation changes greatly at the moment of the fault occurrence, we need to give preference to considering the value of its derivative here. N generally takes a value less than or equal to 3, and specific details are not elaborated here. I i is the rated current of the electrical appliance numbered i. By calculating both temperature and current, the interference of one item can be avoided, improving the accuracy of judgment.

[0048] S4. Judge whether the risk index R i of the electrical appliance is greater than a preset standard risk index R标 , if so, execute S5; if not, execute S6. The preset standard risk index R 标 can be set according to experience, and can also be the value detected by conducting a destructive experiment on the electrical appliance. Of course, it can also be replaced by the risk index calculated from the value detected by the damaged electrical appliance. Its specific value is not the subject protected by this application and will not be elaborated here.

[0049] S5. Determine that the electrical appliance has an operation risk, disconnect the control switch of the electrical appliance, and perform load transfer. When the electrical appliance fails, it will generate heat and cause current instability. Before these symptoms appear, it generally will not cause damage to the electrical appliance. Therefore, by making this determination, we can perform load transfer before the electrical appliance is damaged, thus avoiding damage to the circuit and the electrical appliance, and also avoiding the losses caused by circuit power outages. Then an alarm can be sent, and the number of the electrical appliance with an operation risk is sent to the maintenance personnel, so as to facilitate the maintenance personnel to promptly perform maintenance and troubleshoot faults. When the troubleshooting is completed or it is determined that there is no risk, normal power supply can be restored. When it is repeatedly determined that the electrical appliance has an operation risk but there is no fault during maintenance, the preset standard risk index R 标 can be corrected. Its value can be slightly increased. If it was not determined before the equipment failure, the value of the preset standard risk index R 标 can be reduced. The specific details will not be elaborated here. The preset standard risk index R 标 can be determined in levels and then processed in levels. The level determination and level processing will not be elaborated here.

[0050] S6. Determine that the electrical appliance does not have an operation risk and keep the electrical appliance running normally.

[0051] S7. Determine whether the electrical appliance is a circuit function electrical appliance. If so, execute S8; if not, execute S9. Here, we can divide electrical appliances into function electrical appliances and working electrical appliances. Function electrical appliances are those without which other electrical appliances on the same circuit cannot work properly, such as power supplies, transformers, etc. Working electrical appliances are those that can work properly without this electrical appliance, such as lighting lamps, etc. The specific details will not be elaborated here.

[0052] S8. Obtain the optimal load-transfer electrical appliance with the same function as the electrical appliance in the distribution network. Use the optimal load-transfer electrical appliance as the target electrical appliance to complete the load transfer through corresponding erection. Specifically, it can include obtaining the nodes at both ends of the electrical appliance and the nodes at both ends of the optimal load-transfer electrical appliance, and corresponding erection through the tie switch. When designing the distribution network circuit, control switches need to be configured on the circuits of each electrical appliance. When all the control switches on the same circuit are closed, it ensures that the circuit forms a complete closed circuit. If one of the control switches is disconnected, the electrical appliances on the circuit cannot work. There are tie lines and tie switches corresponding to both ends between each functional electrical appliance, so two electrical appliances with the same function can be used as backups for each other. When one of the electrical appliances has an operation risk, disconnect the corresponding control switch of the electrical appliance, and connect both ends through the tie line and tie switch to both ends of the electrical appliance with the same function, so as to facilitate load transfer. The detailed content in the erection is specific circuit knowledge. Of course, the load transfer can also be completed through existing erection methods, which will not be elaborated here. When there are multiple electrical appliances with the same function in the distribution network, refer to Figure 4 When there are multiple electrical appliances with the same function in the distribution network, the method for obtaining the optimal load-transfer electrical appliance can include: obtaining the real-time current I of the electrical appliances with the same function in the distribution network s , where s is the number of the electrical appliances with the same function, excluding the electrical appliances without operation risk. Then calculate and obtain its operation stability index Q s , and use the electrical appliance with the maximum operation stability index Q s as the optimal load-transfer electrical appliance to erect the load transfer path. The operation stability index Q s can be obtained through calculation, specifically it can be where R s is the risk index of the electrical appliance with the number s of the same function, P s ’ is the current electric power of the electrical appliance with the number s of the same function, and Us is the rated voltage of the electrical appliance with the number s of the same function. By erecting the load transfer path through this method, the electrical appliance with the best stability can be selected for transfer, so that the circuit after load transfer can be the most stable, ensuring the safety and stability of power consumption, and thus avoiding power supply losses.

[0053] S9. If the electrical appliance is not a circuit functional electrical appliance, it proves that the electrical appliance does not affect the work of other electrical appliances, and we can avoid it through a parallel circuit. The parallel circuit can connect a circuit in parallel with the electrical appliance, and a resistor with a resistance similar to that of the electrical appliance, the same electrical appliance or wire can be connected to the circuit. When designing, the general rules of circuit design need to be considered, which will not be elaborated here.

[0054] Embodiment 2

[0055] A load transfer path analysis system based on the distribution network switch topology, which is used to predict faulty electrical appliances and transfer their loads. The load transfer path analysis system based on the distribution network switch topology may include:

[0056] Circuit data detection module: It is used to obtain the operation signals of electrical appliances in the managed distribution network and obtain the circuit data of each electrical appliance according to the operation signals. The circuit data may include: rated electric power P i and actual electric power P i ’.

[0057] Real-time temperature acquisition module: It is used to detect and obtain the real-time temperature T of each electrical appliance i , the real-time temperature acquisition module may be a temperature sensing module, and may also calculate and obtain the real-time temperature T through the rated electric power P i and actual electric power P i ’. i .

[0058] Calculation and analysis module, which is used to calculate the risk index R of the electrical appliance according to the real-time temperature T i and circuit data of the electrical appliance i .

[0059] Judgment and analysis module, which is used to judge whether the risk index R of the electrical appliance i is greater than a preset standard risk index R 标 . If not, it is determined that the electrical appliance has no operation risk and the electrical appliance is kept running normally. If so, it is determined that the electrical appliance has an operation risk, the control switch of the electrical appliance is disconnected, and load transfer is performed. It also judges whether the electrical appliance is a circuit function electrical appliance. If so, the optimal load transfer electrical appliance with the same function as the electrical appliance in the distribution network is obtained, the nodes at both ends of the electrical appliance and the nodes at both ends of the optimal load transfer electrical appliance are obtained, and they are connected through the tie switch. If not, the electrical appliance is not a circuit function electrical appliance, which means that the electrical appliance does not affect the work of other electrical appliances, and we can avoid it through a parallel line.

[0060] Positioning and alarm module, which is used to alarm and send the electrical appliance with operation risk to the maintenance personnel.

[0061] The load transfer path analysis system based on the distribution network switch topology further includes a correction module, which is used to correct the preset standard risk index R 标 . When it is repeatedly determined that the electrical appliance has an operation risk but there is no fault during maintenance, the preset standard risk index R 标 can be corrected, and its value can be slightly increased. If there is no determination before the equipment fails, the preset standard risk index R标 The value can be reduced, so that the standard risk index can be updated in a timely manner, and the accuracy of judgment can be improved. Details are not elaborated herein.

[0062] The above specific implementation manners do not constitute a limitation on the protection scope of the present disclosure. Those skilled in the art should understand that various modifications, combinations, sub - combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. A load transfer path analysis method based on distribution network switch topology, characterized in that: The load transfer path analysis method based on the distribution network switch topology includes: S1. Obtaining operation signals of electrical appliances in the management distribution network, and obtaining circuit data of each electrical appliance according to the operation signals; S2. Detect and obtain the real-time temperature T of each electrical appliance i , where i is the number of the electrical appliance in the distribution network; S3, according to the real-time temperature T of the electrical appliances i and circuit data to calculate the risk index R of electrical appliances i ; S4. Determine the risk index R of electrical appliances i Is it greater than a preset standard risk index R 标 , if yes, execute S5, if no, execute S6; S5. Determine that the electrical appliance has an operation risk, and disconnect the control switch of the electrical appliance; S6. Determine that there is no operating risk for the electrical appliance; S7, determining whether the electrical appliance is a circuit function electrical appliance, if yes, executing S8, if no, executing S9; S8, obtaining an optimal load transfer electrical appliance with the same function as the electrical appliance in the distribution network, and setting up a corresponding electrical appliance with the optimal load transfer electrical appliance as the target electrical appliance to complete the load transfer; S9. Avoid it by connecting lines in parallel.

2. According to claim 1, a load transfer path analysis method based on distribution network switch topology is characterized in that: The circuit data includes: rated power P i and the actual electrical power P i '.

3. According to the load transfer path analysis method based on distribution network switch topology according to claim 1, it is characterized in that: Real-time temperature T i The calculation includes: dividing the area affected by the temperature of the electrical appliance to obtain each internal temperature interference area and sorting them; calculating the area temperature of the internal temperature interference area of ​​the electrical appliance Then take the maximum value of the area temperature of the electrical appliance As the real-time temperature T i .

4. According to claim 1, a method for analyzing a load transfer path based on a distribution network switch topology, characterized in that: The risk index R i =R T W T +R I W I , where R T is the temperature fluctuation risk sub-index, R I is the current fluctuation risk sub-index, W T is the temperature fluctuation risk sub-item weight coefficient, W I It is the sub-item weight coefficient of current fluctuation risk.

5. The load transfer path analysis method based on distribution network switch topology according to claim 4 is characterized in that: Temperature fluctuation risk sub-item weight coefficient W T The calculation method includes: the number of temperature fluctuation damages of electrical appliances of the same type within a preset time period is N T Statistics show that the temperature fluctuation risk sub-item weight coefficient Wherein N' is the damage threshold of the same type of electrical appliances within a preset time period, and Norm() represents a normalization function.

6. According to claim 4, a method for analyzing a load transfer path based on a distribution network switch topology, characterized in that: Current fluctuation risk sub-item weight coefficient W I The calculation method includes: the number of current fluctuation damages of electrical appliances of the same type within a preset time period is N I Statistics show that the sub-item weight coefficient of current fluctuation risk is Wherein N' is the damage threshold of the same type of electrical appliances within a preset time period, and Norm() represents a normalization function.

7. The load transfer path analysis method based on distribution network switch topology according to claim 1 is characterized in that: The method for obtaining the optimal load transfer power supply electrical appliance includes: obtaining the real-time current I of the electrical appliance with the same function in the distribution network s , where s is the serial number of electrical appliances with the same function; calculate and obtain its operation stability index Q s and the operating stability index Q s The largest electrical appliance is used as the optimal load and then transferred to the electrical appliance.

8. The load transfer path analysis method based on distribution network switch topology according to claim 7 is characterized in that: The operation stability index Where R s is the risk index of electrical appliances with the same function numbered s, P s ' is the current power of the electrical appliance with the same function numbered s, U s It is the rated voltage of electrical appliances with the same function and number s.

9. A load transfer path analysis system based on distribution network switch topology, characterized in that: The load transfer path analysis system based on distribution network switch topology includes: A circuit data detection module is used to obtain the operation signals of electrical appliances in the management distribution network, and obtain the circuit data of each electrical appliance according to the operation signals; The real-time temperature acquisition module is used to detect and obtain the real-time temperature T of each electrical appliance. i , where i is the number of the electrical appliance in the distribution network; The calculation and analysis module is used to calculate the real-time temperature T of the electrical appliances. i The risk index R of electrical appliances is calculated by using the circuit data i ; The judgment analysis module is used to judge the risk index R of electrical appliances. i Is it greater than a preset standard risk index R 标 If not, it is determined that the electrical appliance does not have an operating risk and the electrical appliance is kept in normal operation; if yes, it is determined that the electrical appliance has an operating risk, the control switch of the electrical appliance is disconnected, and the load is transferred; it is determined whether the electrical appliance is a circuit functional electrical appliance. If yes, the optimal load transfer electrical appliance with the same function as the electrical appliance in the distribution network is obtained, and the optimal load transfer electrical appliance is used as the target appliance for corresponding construction to complete the load transfer; if not, it is avoided through parallel lines; The positioning alarm module is used to send an alarm signal.

10. A load transfer path analysis system based on distribution network switch topology according to claim 7, characterized in that: It includes a correction module for adjusting the preset standard risk index R 标 Make corrections.

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