Auxiliary analysis method for management of negative loss line of distribution network
By analyzing multiple aspects of the distribution network damage lines, the establishment of a model assessment model was established, the problem of judging errors in the cause of damage lines in existing technologies was solved, and the effective governance of the damaged lines and the reduction of electrical loss consumption were achieved.
Patent Information
- Application Number
- CN202411026082.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-30
- Publication Date
- 2025-01-21
AI Technical Summary
When checking the causes of negative loss lines, the existing distribution network lines have different methods, which can easily lead to errors in judgment, and cannot effectively control line losses and cause power loss.
By analyzing one by one the aging of instruments and equipment, the nonlinear effects of current transformers, the consistency of CT magnification at both ends of the line, the effects of voltage transformer load factors, the effects of secondary circuit voltage drops and external environmental factors, a loss reduction potential assessment model is established and calculated The loss reduction potential of negative loss lines and formulating loss reduction methods for management.
A precise and comprehensive analysis of the damaged lines is realized, and the factors that cause negative losses are accurately judged. Through the formulation of targeted damage reduction methods, effectively treat damage lines and reduce electrical loss.
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of distribution network line loss management, and specifically relates to an auxiliary analysis method for distribution network negative loss line management. Background Art
[0002] Line loss is the energy loss generated during the transmission of electric energy through transmission lines. There are many reasons for line loss. In the line management and maintenance work of power companies, it is necessary to invest a lot of manpower and material resources to investigate the causes of line loss on the corresponding lines in order to improve the utilization rate of electric energy. At the same time, the line loss rate, as a comprehensive technical and economic indicator that characterizes the planning level of the power system and the production and operation management level of the power supply company, plays a vital role in reducing power loss and improving economic benefits. Line loss is divided into high loss and negative loss. Negative loss means that the amount of electricity on the receiving side is greater than the amount of electricity on the power supply side. Theoretically, this situation should not exist. However, in the actual statistics of the power grid, there are still a large number of negative loss areas. In the process of investigating the causes of existing negative loss lines, the investigation methods are different, which can easily lead to misjudgment of the causes of line loss, resulting in the inability to effectively control line loss and causing a large amount of electric energy loss. Therefore, it is necessary to develop an auxiliary analysis method for distribution network negative loss line management with accurate and comprehensive analysis and good negative loss management effect. Summary of the invention
[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide an auxiliary analysis method for distribution network negative loss line management which has accurate and comprehensive analysis and good negative loss management effect.
[0004] The object of the present invention is achieved by: an auxiliary analysis method for distribution network negative loss line management, characterized in that it includes the following steps: Step 1: Collect data and obtain the line loss rate of the negative-loss line; Step 2: Check whether the meter, voltage transformer, and current transformer are overdue. If the equipment is normal, proceed to step 3; if the equipment is overdue, replace the equipment; after the equipment is replaced, if the line loss is normal, record the problem; after the equipment is replaced, if the line loss is still negative, proceed to step 3; Step 3: First, analyze the nonlinear influence of the current transformer on the negative loss line. The nonlinear influence of the current transformer is due to the inherent performance characteristics of the electromagnetic core and the limitations of the processing technology in the manufacturing process, so that the secondary current of the current transformer cannot fully and accurately reflect the primary current; the measurement accuracy of the current transformer is within the load range of 20%-120%. When the load range is exceeded, the measurement error will increase. The main factor for the accuracy deviation of small loads is the hysteresis effect of the core. The smaller the load, the greater the deviation of the measurement result; at the same time, when the load current is greater than 120%, the core of the current transformer will tend to saturation, and the measurement result will also show negative error characteristics. Therefore, the working range of the current transformer to ensure measurement accuracy is within 20%-120%, and it will show negative deviation when it exceeds this range; Secondly, the consistency of the CT ratio at both ends of the negative loss line is analyzed and judged. Because in actual operation, a large part of the transformation ratio at both ends of the line cannot be consistent with the CT transformation ratio value, especially in the 35KV outgoing line of the 220KV substation, most of the CT transformation ratio on the power supply side is greater than the CT transformation ratio on the receiving side. If the load is less than 5%, and the CT transformation ratio of the receiving side is less than the CT transformation ratio of the power supply side, negative line loss will occur. If the load is further reduced to 1%, the power supply side will be zero, while the power sales side will have a small amount of unreasonable power. Secondly, the influence of voltage transformer load rate on negative loss lines is analyzed. Voltage transformers are currently divided into electromagnetic and capacitive types. Under light load conditions, the secondary voltage of capacitive PT is 1.5% higher than that of electromagnetic PT. When different types of PTs are used at both ends of a 220KV line, and the secondary circuit current of the capacitive PT is small, the electric energy calculation will produce a large error, resulting in a large line loss value. Therefore, if electromagnetic PTs are used on the power supply side and capacitive PTs are used on the power sales side, negative line loss will inevitably occur when the line loss value cannot offset the positive error of PT. Finally, the influence of the secondary circuit voltage drop on the negative loss line is analyzed. The secondary circuit voltage drop refers to the percentage of the voltage drop between the secondary terminal of the voltage transformer and the terminal of the electric energy meter relative to the actual secondary voltage of the voltage transformer. The voltage transformer is the necessary channel to connect the terminal and the user-end metering device. In practical applications, there is a long transmission distance between the two terminals. In order to ensure the stability and normality of power transmission, it is usually necessary to use secondary cables and other wires to connect the two ends in series. At the same time, it is necessary to add air switches, fuses, terminal blocks and other necessary accessories to the series circuit. Whether it is the connecting cable or the series accessories, there is a certain impedance at the contact end and inside the material, which will cause a voltage drop when the current flows through the secondary circuit of the voltage transformer, which will lead to a certain deviation between the actual measurement and the true value. Step 4: Based on the situation analysis in steps 2 and 3, establish a corresponding loss reduction potential assessment model, calculate the loss reduction potential of the negative-loss line, and then formulate corresponding loss reduction methods based on the loss reduction potential and carry out loss reduction management.
[0005] The data content in step 1 includes line background information, model, length, measured parameters, power on both sides of the line, bus operating voltage, real-time operating data, and gateway metering data.
[0006] The step 3 also requires analysis of the impact of the weather and the line environment on the line loss.
[0007] Beneficial effects of the present invention: The present invention obtains accurate and comprehensive factors causing negative line loss by analyzing one by one the aging of instruments and equipment, the nonlinear influence of current transformers, the consistency of CT ratios at both ends of the line, the influence of voltage transformer load rate, the influence of secondary circuit voltage drop, the influence of external environmental factors and other aspects. Then, by establishing a loss reduction potential evaluation model, the loss reduction potential of the negative loss line is calculated, and finally a corresponding loss reduction method is formulated according to the loss reduction potential, and loss reduction management is carried out, thereby solving the problem that the negative loss of existing distribution network lines is caused by differences in investigation methods, resulting in incorrect judgment of the cause of line loss, and thus cannot be effectively managed; in general, the present invention has the advantages of accurate and comprehensive analysis and good negative loss management effect. DETAILED DESCRIPTION
[0008] The present invention is further described below.
[0009] Embodiment: An auxiliary analysis method for distribution network negative loss line management, characterized by comprising the following steps: Step 1: Collect data, i.e. line background information, model, length, measured parameters, power on both sides of the line, busbar operating voltage, real-time operating data, and gateway metering data, and obtain the line loss rate of the negative-loss line through calculation; Step 2: Check whether the meter, voltage transformer, and current transformer are overdue. If the equipment is normal, proceed to step 3; if the equipment is overdue, replace the equipment; after the equipment is replaced, if the line loss is normal, record the problem; after the equipment is replaced, if the line loss is still negative, proceed to step 3; Step 3: First, analyze the nonlinear influence of the current transformer on the negative loss line. The nonlinear influence of the current transformer is due to the inherent performance characteristics of the electromagnetic core and the limitations of the processing technology in the manufacturing process, so that the secondary current of the current transformer cannot fully and accurately reflect the primary current; the measurement accuracy of the current transformer is within the load range of 20%-120%. When the load range is exceeded, the measurement error will increase. The main factor for the accuracy deviation of small loads is the hysteresis effect of the core. The smaller the load, the greater the deviation of the measurement result; at the same time, when the load current is greater than 120%, the core of the current transformer will tend to saturation, and the measurement result will also show negative error characteristics. Therefore, the working range of the current transformer to ensure measurement accuracy is within 20%-120%, and it will show negative deviation when it exceeds this range; Secondly, the consistency of the CT ratio at both ends of the negative loss line is analyzed and judged. Because in actual operation, a large part of the transformation ratio at both ends of the line cannot be consistent with the CT transformation ratio value, especially in the 35KV outgoing line of the 220KV substation, most of the CT transformation ratio on the power supply side is greater than the CT transformation ratio on the receiving side. If the load is less than 5%, and the CT transformation ratio of the receiving side is less than the CT transformation ratio of the power supply side, negative line loss will occur. If the load is further reduced to 1%, the power supply side will be zero, while the power sales side will have a small amount of unreasonable power. Secondly, the influence of voltage transformer load rate on negative loss lines is analyzed. Voltage transformers are currently divided into electromagnetic and capacitive types. Under light load conditions, the secondary voltage of capacitive PT is 1.5% higher than that of electromagnetic PT. When different types of PTs are used at both ends of a 220KV line, and the secondary circuit current of the capacitive PT is small, the electric energy calculation will produce a large error, resulting in a large line loss value. Therefore, if electromagnetic PTs are used on the power supply side and capacitive PTs are used on the power sales side, negative line loss will inevitably occur when the line loss value cannot offset the positive error of PT. Finally, the impact of secondary circuit voltage drop on negative-loss lines is analyzed. Secondary circuit voltage drop refers to the percentage of voltage drop between the secondary terminal of the voltage transformer and the terminal of the electric energy meter relative to the actual secondary voltage of the voltage transformer. The voltage transformer is the only way to connect the terminal and the metering device at the user end. In actual applications, there is a long transmission distance between the two terminals. In order to ensure the stability and normal power transmission, it is usually necessary to use secondary cables and other wires to connect the two ends in series. At the same time, it is necessary to add air switches, fuses, terminal blocks and other necessary accessories to the series circuit. Whether it is connecting cables or series accessories, there is a certain impedance at the contact end and inside the material, which will cause a voltage drop when the current flows through the secondary circuit of the voltage transformer, which will lead to a certain deviation between the actual measurement and the true value; at the same time, it is also necessary to analyze the impact of meteorology and the environment in which the line is located on line loss.
[0010] Step 4: Based on the situation analysis in steps 2 and 3, establish a corresponding loss reduction potential assessment model, calculate the loss reduction potential of the negative-loss line, and then formulate corresponding loss reduction methods based on the loss reduction potential and carry out loss reduction management.
[0011] The analysis method described in the present invention first eliminates the influence caused by aging and failure of the instruments and equipment by inspecting the instruments and equipment, and then analyzes the influence of nonlinearity of the current transformer, the detection of CT ratio consistency at both ends of the line, the influence of the voltage transformer load rate, the influence of the secondary circuit voltage drop, the influence of external environmental factors and other aspects one by one, so as to obtain accurate and comprehensive factors causing negative line loss. Then, according to the obtained factors causing negative line loss, a loss reduction potential evaluation model is established, and the loss reduction potential of the negative loss line is calculated according to the actual situation. After completing the above operations, a corresponding loss reduction method is formulated according to the loss reduction potential, and a comprehensive loss reduction management is carried out, so as to solve the problem that the negative loss of the existing distribution network line is caused by the difference in the investigation method, resulting in the wrong judgment of the cause of the line loss, and then the problem that it cannot be effectively managed; in general, the present invention has the advantages of accurate and comprehensive analysis and good negative loss management effect.
[0012] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the specific implementation modes of the present invention can still be modified or replaced by equivalents, and any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.
Claims
1. An auxiliary analysis method for distribution network negative loss line management, characterized in that: The following steps are involved: Step 1: Collect data and obtain the line loss rate of the negative-loss line; Step 2: Check whether the meter, voltage transformer and current transformer are out of service. If the equipment is normal, proceed to step 3; If the equipment is out of service, replace the equipment; if the line loss is normal after the equipment is replaced, record the problem; if the line loss is still negative after the equipment is replaced, go to step 3; Step 3: First, analyze the nonlinear influence of the current transformer on the negative loss line. The nonlinear influence of the current transformer is due to the inherent performance characteristics of the electromagnetic core and the limitations of the processing technology in the manufacturing process, so that the secondary current of the current transformer cannot fully and accurately reflect the primary current; the measurement accuracy of the current transformer is within the load range of 20%-120%. When the load range is exceeded, the measurement error will increase. The main factor for the accuracy deviation of small loads is the hysteresis effect of the core. The smaller the load, the greater the deviation of the measurement result; at the same time, when the load current is greater than 120%, the core of the current transformer will tend to saturation, and the measurement result will also show negative error characteristics. Therefore, the working range of the current transformer to ensure measurement accuracy is within 20%-120%, and it will show negative deviation when it exceeds this range; Secondly, the consistency of the CT ratio at both ends of the negative loss line is analyzed and judged. Because in actual operation, a large part of the transformation ratio at both ends of the line cannot be consistent with the CT transformation ratio value, especially in the 35KV outgoing line of the 220KV substation, most of the CT transformation ratio on the power supply side is greater than the CT transformation ratio on the receiving side. If the load is less than 5%, and the CT transformation ratio of the receiving side is less than the CT transformation ratio of the power supply side, negative line loss will occur. If the load is further reduced to 1%, the power supply side will be zero, while the power sales side will have a small amount of unreasonable power. Secondly, the influence of voltage transformer load rate on negative loss lines is analyzed. Voltage transformers are currently divided into electromagnetic and capacitive types. Under light load conditions, the secondary voltage of capacitive PT is 1.5% higher than that of electromagnetic PT. When different types of PTs are used at both ends of a 220KV line, and the secondary circuit current of the capacitive PT is small, the electric energy calculation will produce a large error, resulting in a large line loss value. Therefore, if electromagnetic PTs are used on the power supply side and capacitive PTs are used on the power sales side, negative line loss will inevitably occur when the line loss value cannot offset the positive error of PT. Finally, the influence of the secondary circuit voltage drop on the negative loss line is analyzed. The secondary circuit voltage drop refers to the percentage of the voltage drop between the secondary terminal of the voltage transformer and the terminal of the electric energy meter relative to the actual secondary voltage of the voltage transformer. The voltage transformer is the necessary channel to connect the terminal and the user-end metering device. In practical applications, there is a long transmission distance between the two terminals. In order to ensure the stability and normality of power transmission, it is usually necessary to use secondary cables and other wires to connect the two ends in series. At the same time, it is necessary to add air switches, fuses, terminal blocks and other necessary accessories to the series circuit. Whether it is the connecting cable or the series accessories, there is a certain impedance at the contact end and inside the material, which will cause a voltage drop when the current flows through the secondary circuit of the voltage transformer, which will lead to a certain deviation between the actual measurement and the true value. Step 4: Based on the situation analysis in steps 2 and 3, establish a corresponding loss reduction potential assessment model, calculate the loss reduction potential of the negative-loss line, and then formulate corresponding loss reduction methods based on the loss reduction potential and carry out loss reduction management.
2. The auxiliary analysis method for managing the negative loss line of the distribution network according to claim 1, characterized in that: The data content in step 1 includes line background information, model, length, measured parameters, power on both sides of the line, bus operating voltage, real-time operating data, and gateway metering data.
3. The auxiliary analysis method for managing the negative loss line of a distribution network according to claim 1, characterized in that: The step 3 also requires analysis of the impact of the weather and the line environment on the line loss.