Primary and secondary collaborative planning method based on novel power distribution system

Abstract

The invention discloses a primary and secondary collaborative planning method based on a novel power distribution system, and relates to the technical field of power system optimization, and the method comprises the following specific steps: constructing a power distribution network model and fault feature analysis, designing an adaptive protection mechanism, realizing a rapid fault processing mechanism, and performing primary and secondary system collaborative planning. And implementing and verifying: implementing a planning method in the power distribution network, installing and debugging related equipment, carrying out field test, and verifying the effectiveness of an adaptive protection mechanism and a fault rapid processing mechanism, the running state of the power distribution network is monitored in real time, and the protection constant value is automatically adjusted according to the monitored fault characteristic parameters, so that the reliability of the power distribution network is improved. Therefore, the adaptive capacity of the system to a complex and changeable operation environment is remarkably improved, the dynamic adjustment mechanism can quickly respond to dynamic factors of new energy output fluctuation and load change, it is ensured that a protection strategy is always matched with the operation state of the system, and the problem of protection maloperation or operation refusal caused by rigid setting of a fixed value is effectively prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of power system optimization, and in particular to a primary-secondary collaborative planning method based on a novel power distribution system. Background Art

[0002] In the power system, the distribution system serves as a bridge between power sources and users. Its stability and reliability are of great significance to ensuring power supply. However, with the transformation of the global energy structure and the rapid development of renewable energy technology, the large-scale access of distributed new energy has brought unprecedented challenges to the traditional distribution system.

[0003] The protection technology of traditional distribution systems mainly relies on fixed protection settings and relatively simple logical judgments, which makes it difficult to accurately reflect the dynamic changes of distribution networks in real time. When distributed renewable energy sources are connected in large quantities, the fault characteristics of distribution networks become complex and diverse. Traditional protection methods often have the following problems: First, the protection settings are unreasonable, resulting in false protection or refusal to operate; second, fault detection and positioning are not accurate enough, which prolongs the fault handling time; third, there is a lack of coordinated planning of primary and secondary systems, which makes the protection mechanism mismatch with the physical structure of the distribution network, reducing the overall performance and reliability of the system. In addition, traditional protection mechanisms often rely on equipment such as voltage transformers, which may be interfered with in complex electromagnetic environments, affecting protection performance.

[0004] In view of the above problems, it is necessary to optimize the existing primary and secondary system collaborative planning method. By constructing a distribution network model and fault characteristic analysis, an adaptive protection mechanism is designed that can monitor the system operation status in real time and automatically adjust the protection setting. At the same time, the single-ended directional protection principle that does not rely on traditional voltage transformers is studied. Therefore, it is of great significance to develop a primary and secondary collaborative planning method based on a new distribution system that can comprehensively realize the above characteristics. Summary of the invention

[0005] The purpose of the present invention is to make up for the shortcomings of the existing technology and provide a primary-secondary collaborative planning method based on a new distribution system. It can design a set of adaptive protection mechanisms that can monitor the system operation status in real time and automatically adjust the protection settings by constructing a distribution network model and fault characteristic analysis. At the same time, it studies the single-ended directional protection principle that does not rely on traditional voltage transformers, and combines high-speed communication technology to achieve rapid data interaction between protection devices, significantly improving the ability to quickly handle faults.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: a primary and secondary collaborative planning method based on a new power distribution system, the method comprising the following specific steps:

[0007] S100, build distribution network model and fault characteristic analysis: build a distribution network model including distributed renewable energy, simulate the operation status under different renewable energy access scenarios, use simulation tools to analyze the impact of renewable energy access on the distribution characteristics of distribution network faults, and extract key fault parameters;

[0008] S200, design of adaptive protection mechanism: based on the analysis results, an adaptive protection algorithm is designed, and a protection setting adjustment strategy is set. The protection setting is dynamically adjusted according to the line fault characteristic parameters monitored in real time, and a single-ended directional protection principle that does not rely on traditional voltage transformers is introduced;

[0009] S300, realizing fast fault handling mechanism: researching and implementing the single-ended directional protection principle that does not rely on traditional voltage transformers, and using carrier communication and 5G high-speed communication technology to establish a fast data interaction mechanism between protection devices, while designing a fault isolation strategy to quickly locate and isolate the fault area when a fault occurs;

[0010] S400, primary and secondary system coordinated planning: Comprehensively analyze the impact of distributed renewable energy access on the primary system of the distribution network, optimize the physical form and grid structure, configure corresponding secondary protection equipment according to the requirements of adaptive protection mechanism and rapid fault handling mechanism, and formulate primary and secondary coordinated planning scheme;

[0011] S500, Implementation and Verification: Implement the planning method in the distribution network, install and commission related equipment, conduct field tests, verify the effectiveness of the adaptive protection mechanism and the fast fault handling mechanism, and make necessary adjustments and optimizations based on the test results.

[0012] Furthermore, the step S100 includes:

[0013] S101, collect basic data of distribution network, including grid structure, equipment parameters and distributed new energy access points;

[0014] S102, using power system simulation software to build a distribution network model including distributed renewable energy, setting different renewable energy access scenarios, and simulating various fault conditions;

[0015] S103, running the simulation model, recording and collecting line fault data, including fault current, voltage waveform and fault location, performing statistical analysis on the collected line fault data, and extracting key fault characteristic parameters.

[0016] Furthermore, the step S103 performs statistical analysis on the collected line fault data to extract key fault characteristic parameters. Specifically, for the line fault data set D = {(x1, y1), ..., (x n ,y n )}, where x iis the feature vector of the i-th fault sample, y i is the label associated with the sample, and the fault extraction formula is: z = W T φ(x)+b, where z is the extracted key fault feature parameter vector, W is the transformation matrix, whose column vector defines the mapping from the original feature space to the key feature space, φ(x) is the feature transformation function, and b is the bias vector. When a current fault occurs, the current is used as the fault feature parameter to collect the current change data before and after the fault. When a voltage fault occurs, the voltage is used as the fault feature parameter to collect the voltage change data before and after the fault. The above fault feature parameters need to be based on the protection action delay time set by the circuit breaker.

[0017] Furthermore, the step S200 includes:

[0018] S201, according to the fault characteristic analysis results, determine the protection strategy requirements and design an adaptive protection algorithm to monitor the operation status of the distribution network in real time, including current and voltage parameters;

[0019] S202, setting logic for dynamically adjusting protection settings in the algorithm, and automatically adjusting protection settings according to monitored fault characteristic parameters;

[0020] S203, integrating the algorithm into the protection device and performing on-site debugging and verification.

[0021] Furthermore, the step S201 determines the protection strategy requirements based on the line fault feature analysis results and designs an adaptive protection algorithm. Specifically, an adaptive function is defined, which outputs the protection strategy based on the real-time status and historical information. The calculation formula is: t =π(s t ,h t ), where s t represents the real-time status of the distribution network at time t, h t represents the historical information up to time t, a t It is based on t and h t The calculated protection strategy is implemented by adjusting the parameters and structure of the π function when the function is updated according to the real-time status. The iterative formula is: new =Update(π old ,Δ), where π old is the adaptive function before updating, Δ is the update amount calculated based on feedback, and π new is the updated adaptive function.

[0022] Furthermore, the step S202 includes:

[0023] (1) Formulate a protection setting adjustment strategy based on the fault identification results and the protection requirements of the power system, and optimize the formulated protection setting adjustment strategy by considering the complexity and uncertainty of the power system;

[0024] (2) According to the protection setting adjustment strategy, combined with the real-time monitored power system parameters, a new protection setting is calculated, and the calculated new protection setting is sent to the protection device to achieve dynamic adjustment of the protection setting;

[0025] (3) Collect system operation data and protection action records after the protection setting value adjustment, conduct feedback analysis, evaluate the effect of the protection setting value adjustment, check whether the expected protection effect has been achieved, and troubleshoot and handle any problems that arise.

[0026] Furthermore, the step S300 includes:

[0027] S301, research and determine the implementation scheme of the single-ended directional protection principle that does not rely on the traditional voltage transformer;

[0028] S302, design and develop a protection equipment data interaction system based on carrier communication and 5G high-speed communication technology;

[0029] S303, formulate a fault isolation strategy, including determining the criteria for fault isolation and the time sequence of isolation actions, integrating a fast fault handling mechanism in the protection device, and conducting tests.

[0030] Furthermore, the implementation scheme of step S301 that does not rely on the single-ended directional protection principle of the traditional voltage transformer is:

[0031] (1) Install high-sensitivity current and voltage sensors on one side of the DC line to detect transient traveling waves and current mutations Δi(t) and voltage mutations Δu(t);

[0032] (2) Calculate the transient power ΔP(t) based on the detected current mutation Δi(t) and voltage mutation Δu(t):

[0033] ΔP(t)=Δi(t)·Δu(t)

[0034] Calculate the transient power energy E using the trapezoidal method of numerical integration P :

[0035]

[0036] (3) Determine the fault direction based on the calculated parameters: When the transient power energy E P >0, a reverse fault occurs; transient power energy E P When <0, a positive direction fault occurs.

[0037] (4) Fault judgment criteria inside and outside the forward zone: Perform 6-scale wavelet decomposition on the fault current signal collected by the protection device, obtain the first-scale high-frequency energy E1 and the sixth-scale low-frequency energy E6, and define the ratio K of E1 to E6 P for:

[0038]

[0039] Where K is the proportionality coefficient, and the K value is selected by comprehensively considering the sampling frequency and the time window length;

[0040] Whether it occurs in the protected area using the high-low frequency energy ratio K P As the criterion for protection action inside and outside the zone: when K P >K0, the fault occurs in the protection zone, otherwise it occurs outside the zone; if it is judged to be a fault in the zone, the protection action is immediately started, including disconnecting the faulty line and issuing an alarm signal; K0 is the protection action threshold, and K0 is taken as 1.

[0041] (5) Assuming that the fault occurs between two monitoring points and the traveling wave propagates from the fault point to the two monitoring points, the detected traveling wave signal is analyzed using digital signal processing technology to extract the waveform, traveling wave velocity v, and the time difference Δt between the traveling wave and the two monitoring points;

[0042] The following formula is used for analysis and calculation:

[0043]

[0044] where c is the speed of light in a vacuum, μ r is the relative magnetic permeability, ε r is the relative dielectric constant;

[0045] Δt=t2-t1

[0046] Where t1 is the time when the traveling wave reaches monitoring point 1, and t2 is the time when the traveling wave reaches monitoring point 2;

[0047] Define the fault location x, and calculate the fault location through the traveling wave velocity v and the time difference Δt when the traveling wave reaches the two monitoring points. The formula is as follows:

[0048]

[0049] Furthermore, the step S400 includes:

[0050] S401, comprehensively analyze the impact of distributed renewable energy access on the primary system of the distribution network, including power flow distribution and voltage stability, and optimize the physical form and grid structure of the distribution network based on the analysis results;

[0051] S402, configuring corresponding secondary protection devices according to the requirements of the adaptive protection mechanism and the rapid fault processing mechanism;

[0052] S403, formulate a planning scheme for the coordinated work of the primary and secondary systems, including protection setting, communication protocol selection and data transmission path planning, and evaluate the planning scheme.

[0053] Furthermore, the step S500 includes:

[0054] S501: Install and debug equipment in the actual distribution network according to the planned solution, and conduct comprehensive system coordination;

[0055] S502, monitor the actual operation of the system, collect and analyze the operation data, evaluate the effect of adaptive protection and rapid fault handling mechanism, and the effectiveness of primary and secondary system coordinated planning;

[0056] S503: Optimize and adjust the system according to the evaluation result.

[0057] Compared with the existing technology, this primary and secondary collaborative planning method based on the new distribution system has the following beneficial effects:

[0058] 1. The present invention monitors the operating status of the distribution network in real time and automatically adjusts the protection setting according to the monitored fault characteristic parameters, thereby significantly improving the system's adaptability to complex and changeable operating environments. This dynamic adjustment mechanism can quickly respond to dynamic factors such as new energy output fluctuations and load changes, ensuring that the protection strategy always matches the system operating status, and effectively preventing protection misoperation or refusal to operate due to rigid setting of the setting value.

[0059] 2. The present invention can quickly identify the fault type, direction and location through an adaptive protection mechanism and trigger corresponding protection actions. At the same time, combined with the single-ended directional protection principle that does not rely on traditional voltage transformers and high-speed communication technology, the data interaction between protection devices is faster and more accurate, thereby significantly shortening the time for fault location and processing.

[0060] 3. The present invention combines transient traveling waves and transient power to comprehensively analyze and locate faults, thereby providing a more comprehensive understanding and analysis of fault events. At the same time, the trapezoidal method is used for numerical integration to improve the accuracy of transient power energy calculation, thereby optimizing the performance of the protection scheme and improving the fault response speed and system reliability.

[0061] Other advantages, objectives and features of the present invention will be set forth in part in the following description and, in part, will be apparent to those skilled in the art based on an examination of the following or may be taught from the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0063] Figure 1 This is a process operation diagram of a primary-secondary collaborative planning method based on a new distribution system.

[0064] Figure 2 This is a flow chart of a primary-secondary collaborative planning method based on a new distribution system.

[0065] Figure 3 The figure is a flow chart of a rapid fault handling mechanism based on a new type of power distribution system. DETAILED DESCRIPTION

[0066] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] Embodiment 1

[0068] This embodiment describes in detail the specific steps of using a primary-secondary collaborative planning method based on a new power distribution system.

[0069] For the distribution network model construction and fault characteristic analysis stage (S100), a distribution network model including distributed renewable energy is constructed, the operating status under different renewable energy access scenarios is simulated, and the impact of renewable energy access on the distribution characteristics of distribution network faults is analyzed by using simulation tools, and key fault parameters are extracted; the basic data of the distribution network is comprehensively collected, including a detailed grid structure diagram, technical parameters of various equipment, the location and capacity of distributed renewable energy access points, etc., and advanced power system simulation software (such as MATLAB / Simulink, PSASP, etc.) is used to construct a distribution network model including distributed renewable energy based on the collected data. The model fully considers the output characteristics, load changes, network topology and other factors of renewable energy, and sets a variety of renewable energy access scenarios in the model to simulate the operating status under different weather conditions and load levels, as well as various possible fault conditions, and simulate various fault conditions; the simulation model is run to record and collect line fault data, including fault current, voltage waveform and fault location, and the collected line fault data is statistically analyzed to extract key fault characteristic parameters. Through simulation operation, a large amount of fault data is recorded and collected, and in-depth statistical analysis is performed on the collected line fault data to extract key fault characteristic parameters. Specifically, for the line fault data set D = {(x1, y1),…, (x n ,y n )}, where x i is the feature vector of the i-th fault sample, y i is the label associated with the sample, and the fault extraction formula is: z = W T φ(x)+b, where z is the extracted key fault feature parameter vector, W is the transformation matrix, whose column vector defines the mapping from the original feature space to the key feature space, φ(x) is the feature transformation function, and b is the bias vector. When a current fault occurs, the current is used as the fault feature parameter to collect the current change data before and after the fault. When a voltage fault occurs, the voltage is used as the fault feature parameter to collect the voltage change data before and after the fault. The above fault feature parameters need to be based on the protection action delay time set by the circuit breaker to provide data support for the subsequent adaptive protection mechanism design.

[0070] For the stage of designing an adaptive protection mechanism (S200), based on the analysis results, the requirements of the protection mechanism are clarified, including the protection range, protection speed, and protection sensitivity, and an adaptive protection algorithm is designed. The algorithm can monitor the operating status of the distribution network in real time, including key parameters such as current and voltage. The algorithm is provided with logic for dynamically adjusting the protection constants, and automatically adjusts the protection constants according to the monitored fault characteristic parameters to adapt to changes in system operating conditions. In the algorithm design, the single-ended directional protection principle that does not rely on traditional voltage transformers is introduced to improve the reliability and accuracy of the protection. At the same time, carrier communication and 5G high-speed communication technology are used to establish a fast data interaction mechanism between protection devices to provide technical support for rapid fault processing. The adaptive protection algorithm is integrated into the protection device, and on-site debugging and verification are carried out. By simulating fault conditions, the effectiveness and reliability of the protection mechanism are verified to ensure that faults can be responded to accurately and quickly in actual operation.

[0071] Design an adaptive protection algorithm, set the protection setting adjustment strategy, dynamically adjust the protection setting according to the line fault characteristic parameters monitored in real time, and introduce the single-ended directional protection principle that does not rely on traditional voltage transformers; determine the protection strategy requirements based on the fault characteristic analysis results, and design an adaptive protection algorithm to monitor the operating status of the distribution network in real time, including current and voltage parameters; define an adaptive function that outputs the protection strategy based on the real-time status and historical information. The calculation formula is: t =π(s t ,h t ), where s t represents the real-time status of the distribution network at time t, h t represents the historical information up to time t, a t It is based on t and h t The calculated protection strategy is implemented by adjusting the parameters and structure of the π function when the function is updated according to the real-time status. The iterative formula is: new =Update(π old ,Δ), where π old is the adaptive function before updating, Δ is the update amount calculated based on feedback, and π new is the updated adaptive function.

[0072] The logic of dynamically adjusting the protection setting is set in the algorithm, and the protection setting is automatically adjusted according to the monitored fault characteristic parameters; the protection setting adjustment strategy is formulated according to the fault identification results and the protection requirements of the power system, and the formulated protection setting adjustment strategy is optimized considering the complexity and uncertainty of the power system; according to the protection setting adjustment strategy, the new protection setting is calculated in combination with the real-time monitored power system parameters, and the calculated new protection setting is sent to the protection device to achieve dynamic adjustment of the protection setting; the system operation data and protection action records after the protection setting adjustment are collected, and feedback analysis is performed to evaluate the effect of the protection setting adjustment, check whether the expected protection effect is achieved, and troubleshoot and handle the problems that arise. The algorithm is integrated into the protection device, and on-site debugging and verification are performed.

[0073] For the stage of realizing the rapid fault handling mechanism (S300), the single-ended directional protection principle that does not rely on the traditional voltage transformer is studied and implemented, and the carrier communication and 5G high-speed communication technology are used to establish a rapid data interaction mechanism between protection devices. At the same time, a fault isolation strategy is designed to quickly locate and isolate the fault area when a fault occurs; highly sensitive current and voltage sensors are installed on one side of the DC line to detect transient traveling waves and current mutations Δi(t) and voltage mutations Δu(t); transient power ΔP(t) is calculated based on the detected current mutations Δi(t) and voltage mutations Δu(t):

[0074] ΔP(t)=Δi(t)·Δu(t);

[0075] Calculate the transient power energy E using the trapezoidal method of numerical integration P :

[0076]

[0077] Determine the fault direction based on the calculated parameters: When the transient power energy E P >0, a reverse fault occurs; transient power energy E P <0, a positive fault occurs; Fault criterion inside and outside the positive zone: perform 6-scale wavelet decomposition on the fault current signal collected by the protection device, obtain the first-scale high-frequency energy E1 and the sixth-scale low-frequency energy E6, and define the ratio K of E1 to E6 P for:

[0078]

[0079] Where K is the proportionality coefficient, and the K value is selected by comprehensively considering the sampling frequency and the time window length;

[0080] Whether it occurs in the protected area using the high-low frequency energy ratio K P As the criterion for protection action inside and outside the zone: when KP >K0, the fault occurs in the protection zone, otherwise it is a fault outside the zone; if it is judged to be a fault in the zone, the protection action is immediately started, including disconnecting the faulty line and sending an alarm signal; K0 is the protection action threshold, and K0 is taken as 1; Assuming that the fault occurs between two monitoring points, and the traveling wave propagates from the fault point to the two monitoring points, the detected traveling wave signal is analyzed using digital signal processing technology to extract the waveform, the traveling wave speed v and the time difference Δt when the traveling wave reaches the two monitoring points;

[0081] The following formula is used for analysis and calculation:

[0082]

[0083] where c is the speed of light in a vacuum, μ r is the relative magnetic permeability, ε r is the relative dielectric constant;

[0084] Δt=t2-t1

[0085] Where t1 is the time when the traveling wave reaches monitoring point 1, and t2 is the time when the traveling wave reaches monitoring point 2;

[0086] Define the fault location x, and calculate the fault location through the traveling wave velocity v and the time difference Δt when the traveling wave reaches the two monitoring points. The formula is as follows:

[0087]

[0088] Design and develop a data interaction system for protection equipment based on carrier communication and 5G high-speed communication technology; formulate a fault isolation strategy, including determining the criteria for fault isolation and the time sequence of isolation actions, integrate a rapid fault handling mechanism into the protection equipment, and conduct tests.

[0089] The solution should be able to accurately determine the fault direction and locate the fault location without relying on voltage transformers. It should design and develop a protection equipment data interaction system based on carrier communication or high-speed communication technologies such as 5G. The system should be able to achieve fast and accurate data transmission and sharing between protection devices, provide real-time and comprehensive information support for rapid fault handling, formulate detailed fault isolation strategies, including determining the criteria for fault isolation, the time sequence of isolation actions, etc., integrate a rapid fault handling mechanism in the protection equipment, and conduct on-site testing to ensure that the fault area can be quickly located and isolated when a fault occurs, reducing the scope and time of the fault's impact on the system.

[0090] For the primary and secondary system collaborative planning stage (S400),

[0091] Comprehensively analyze the impact of distributed renewable energy access on the primary system of the distribution network, optimize the physical form and grid structure, configure corresponding secondary protection equipment according to the needs of adaptive protection mechanism and rapid fault handling mechanism, and formulate a primary and secondary coordinated planning scheme; Comprehensively analyze the impact of distributed renewable energy access on the primary system of the distribution network, including power flow distribution, voltage stability and other aspects. According to the analysis results, optimize the physical form and grid structure of the distribution network, improve the operation efficiency and stability of the system, and configure corresponding secondary protection equipment according to the needs of adaptive protection mechanism and rapid fault handling mechanism. These devices should be able to meet the requirements of the protection mechanism for data collection, processing, transmission and other aspects to ensure the effective implementation of the protection mechanism. At the same time, formulate a planning scheme for the coordinated work of the primary and secondary systems, including protection setting, communication protocol selection, data transmission path planning and other aspects. Carry out detailed evaluation and optimization of the planning scheme to ensure its feasibility and effectiveness in actual operation.

[0092] For the implementation and verification phase (S500), the equipment is installed and debugged in the actual distribution network according to the planning scheme. The planning method is implemented in the distribution network, the relevant equipment is installed and debugged, field tests are conducted, and comprehensive system joint debugging is carried out, including the linkage test between the protection mechanism and the primary system, the reliability test of the communication system, etc. Through the joint debugging, potential problems and hidden dangers are discovered and solved, the effectiveness of the adaptive protection mechanism and the rapid fault handling mechanism is verified, and necessary adjustments and optimizations are made according to the test results. According to the planning scheme, the equipment is installed and debugged in the actual distribution network, and comprehensive system joint debugging is carried out; the actual operation of the system is monitored, the operation data is collected and analyzed, the effect of the adaptive protection and the rapid fault handling mechanism and the effectiveness of the coordinated planning of the primary and secondary systems are evaluated, and all equipment can operate normally and meet the requirements of the protection mechanism. At the same time, the actual operation of the system is monitored, the operation data is collected and analyzed, and the necessary adjustments and optimizations are made to the system according to the evaluation results and feedback to improve its performance and reliability. Optimize and adjust the system.

[0093] Embodiment 2

[0094] Based on the first embodiment, this embodiment describes in detail a specific application of an adaptive protection mechanism based on a primary-secondary collaborative planning method for a novel power distribution system.

[0095] Deploy high-precision current and voltage sensors, as well as sensors for monitoring the output of distributed renewable energy, at key locations in the distribution network to ensure real-time and accurate acquisition of system operation data. Use data acquisition systems (such as SCADA systems) to collect sensor data in real time, and use data encryption and compression technology to reduce the burden of data transmission. Preprocess the collected data, including denoising, filtering, data synchronization, etc., to ensure data quality and accuracy, and provide a reliable data basis for subsequent analysis.

[0096] The algorithm is used to perform deep mining on the preprocessed data to extract key fault characteristic parameters. Specifically, for the line fault data set D = {(x1, y1),…, (x n ,y n )}, where x i is the feature vector of the i-th fault sample, y i is the label associated with the sample, and the fault extraction formula is: z = W T φ(x)+b, where z is the extracted key fault feature parameter vector, W is the transformation matrix, whose column vector defines the mapping from the original feature space to the key feature space, φ(x) is the feature transformation function, and b is the bias vector. These parameters include but are not limited to fault type, fault location, fault duration, fault current waveform, etc. The extracted fault features are optimized through feature selection, feature dimensionality reduction and other technologies to reduce redundant information and improve the processing efficiency and accuracy of subsequent algorithms.

[0097] According to the actual situation and protection requirements of the distribution network, the adaptive protection algorithm is initialized, including protection setting, protection range, and protection strategy. The algorithm receives data from sensors in real time and identifies faults according to preset criteria. Once a line fault is detected, the protection action is immediately started. According to the real-time monitored fault characteristic parameters and the operating status of the system, the algorithm dynamically adjusts the protection setting to adapt to changes in system operating conditions. During the adjustment process, the algorithm considers historical information and real-time status, and improves the accuracy and reliability of protection by iteratively optimizing the protection strategy. Specifically, an adaptive function is defined, which outputs the protection strategy according to the real-time status and historical information. The calculation formula is: t =π(s t ,h t ), where s t represents the real-time status of the distribution network at time t, h t represents the historical information up to time t, a t It is based on t and h t The calculated protection strategy is implemented by adjusting the parameters and structure of the π function when the function is updated according to the real-time status. The iterative formula is: new =Update(π old ,Δ), where π old is the adaptive function before updating, Δ is the update amount calculated based on feedback, and π new is the updated adaptive function.

[0098] Based on the calculation results of the adaptive protection algorithm, new protection settings are calculated. These settings take into account the real-time status of the system, fault characteristics and protection strategy requirements. The new protection settings are sent to the corresponding protection devices through a secure and reliable communication method. During the sending process, data encryption and verification mechanisms are used to ensure the security and integrity of the data. After receiving the new protection settings, the protection device immediately updates the settings to ensure that the protection action can be performed according to the new protection settings in subsequent operation.

[0099] Through the SCADA system or other monitoring means, the operating status and protection effect of the protection equipment are monitored in real time, and key indicators such as protection action records, fault isolation time, system recovery time, etc. are recorded. The protection effect is evaluated to check whether the expected protection effect has been achieved. The evaluation indicators include the accuracy of protection action, the speed of fault isolation, the time of system recovery, etc. According to the evaluation results and feedback, the adaptive protection mechanism is optimized and adjusted. The optimization content may include algorithm improvement, adjustment of protection settings, optimization of communication protocols, etc. Through continuous optimization, the performance and reliability of the adaptive protection mechanism are improved.

[0100] Embodiment 3

[0101] The protection plan for the urban core area of ​​the urban grid is as follows: distributed photovoltaic power sources are connected to the grid through 380 / 220V voltage; the 10kV cable network grid structure is a cable single-ring network, double-ring network, and double-end structure. The load types are mainly government agencies, residents' lives, hospitals, schools, and charging stations. The grid contains new elements such as storage;

[0102] In terms of secondary equipment configuration: the 10kV line is equipped with three-stage overcurrent protection and three-phase primary reclosing, the 10kV distribution transformer is equipped with two-stage overcurrent protection + zero-sequence overcurrent protection, "three remote" distribution automation terminal and other functions; following the principles of "no large-scale demolition and construction" and "one terminal per substation", new substations and existing substations with distributed power source access are deployed with substation terminals, and existing substations without distributed photovoltaic access are still mainly equipped with concentrators.

[0103] Information flow: Information on 10kV busbars and switches in substations within the power supply grid is transmitted to the dispatching automation master station through the dispatching data network; information on 10kV line switch stations, substation terminals, etc. is uploaded to the distribution automation master station via wireless / optical fiber; information on concentrators is uploaded to the power consumption information collection master station via wireless;

[0104] Control flow: The dispatching automation master station directly controls the 10kV busbar, switches, etc. in the substation; the distribution 10kV line switchgear, substation terminals, etc. are all controlled by the distribution automation master station.

[0105] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A primary and secondary collaborative planning method based on a new distribution system, characterized in that: The method comprises the following specific steps: S100, build distribution network model and fault characteristic analysis: build a distribution network model including distributed renewable energy, simulate the operation status under different renewable energy access scenarios, use simulation tools to analyze the impact of renewable energy access on the distribution characteristics of distribution network faults, and extract key fault parameters; S200, design of adaptive protection mechanism: based on the analysis results, an adaptive protection algorithm is designed, and a protection setting adjustment strategy is set. The protection setting is dynamically adjusted according to the line fault characteristic parameters monitored in real time, and a single-ended directional protection principle that does not rely on traditional voltage transformers is introduced; S300, realizing fast fault handling mechanism: researching and implementing the single-ended directional protection principle that does not rely on traditional voltage transformers, and using carrier communication and 5G high-speed communication technology to establish a fast data interaction mechanism between protection devices, while designing a fault isolation strategy to quickly locate and isolate the fault area when a fault occurs; S400, primary and secondary system coordinated planning: Comprehensively analyze the impact of distributed renewable energy access on the primary system of the distribution network, optimize the physical form and grid structure, configure corresponding secondary protection equipment according to the requirements of adaptive protection mechanism and rapid fault handling mechanism, and formulate primary and secondary coordinated planning scheme; S500, Implementation and Verification: Implement the planning method in the distribution network, install and commission related equipment, conduct field tests, verify the effectiveness of the adaptive protection mechanism and the fast fault handling mechanism, and make necessary adjustments and optimizations based on the test results.

2. According to claim 1, a primary and secondary collaborative planning method based on a new power distribution system is characterized in that: The step S100 includes: S101, collect basic data of distribution network, including grid structure, equipment parameters and distributed new energy access points; S102, using power system simulation software to build a distribution network model including distributed renewable energy, setting different renewable energy access scenarios, and simulating various fault conditions; S103, running the simulation model, recording and collecting line fault data, including fault current, voltage waveform and fault location, performing statistical analysis on the collected line fault data, and extracting key fault characteristic parameters.

3. The primary and secondary collaborative planning method based on a new power distribution system according to claim 2 is characterized in that: The step S103 is to statistically analyze the collected line fault data and extract key line fault characteristic parameters. Specifically, for the line fault data set D = {x1, y1, ..., x n ,y n }, where x i is the feature vector of the i-th fault sample, y i is the label associated with the sample, and the fault extraction formula is: z = W T φx+b, where z is the extracted key fault feature parameter vector, W is the transformation matrix, whose column vector defines the mapping from the original feature space to the key feature space, φx is the feature transformation function, and b is the bias vector. When a current fault occurs, the current is used as the fault feature parameter to collect the current change data before and after the fault. When a voltage fault occurs, the voltage is used as the fault feature parameter to collect the voltage change data before and after the fault. The above fault feature parameters need to be based on the protection action delay time set by the circuit breaker.

4. According to claim 1, a primary and secondary collaborative planning method based on a new power distribution system is characterized in that: The step S200 includes: S201, according to the fault characteristic analysis results, determine the protection strategy requirements and design an adaptive protection algorithm to monitor the operation status of the distribution network in real time, including current and voltage parameters; S202, setting logic for dynamically adjusting protection settings in the algorithm, and automatically adjusting protection settings according to monitored fault characteristic parameters; S203, integrating the algorithm into the protection device and performing on-site debugging and verification.

5. The primary and secondary collaborative planning method based on a new power distribution system according to claim 4 is characterized in that: In step S201, according to the line fault characteristic analysis result, the protection strategy requirement is determined, and an adaptive protection algorithm is designed. Specifically, an adaptive function is defined, which outputs the protection strategy according to the real-time status and historical information. The calculation formula is: t =πs t ,h t , where s t represents the real-time status of the distribution network at time t, h t represents the historical information up to time t, a t It is based on t and h t The calculated protection strategy is implemented by adjusting the parameters and structure of the π function when the function is updated according to the real-time status. The iterative formula is: new =Updateπ old ,Δ, where π old is the adaptive function before updating, Δ is the update amount calculated based on feedback, and π new is the updated adaptive function.

6. The primary and secondary collaborative planning method based on a new power distribution system according to claim 4 is characterized in that: The step S202 includes: (1) Formulate a protection setting adjustment strategy based on the fault identification results and the protection requirements of the power system, and optimize the formulated protection setting adjustment strategy by considering the complexity and uncertainty of the power system; (2) According to the protection setting adjustment strategy, combined with the real-time monitored power system parameters, a new protection setting is calculated, and the calculated new protection setting is sent to the protection device to achieve dynamic adjustment of the protection setting; (3) Collect system operation data and protection action records after the protection setting value adjustment, conduct feedback analysis, evaluate the effect of the protection setting value adjustment, check whether the expected protection effect has been achieved, and troubleshoot and handle any problems that arise.

7. The primary and secondary collaborative planning method based on a new power distribution system according to claim 1 is characterized in that: The step S300 includes: S301, research and determine the implementation scheme of the single-ended directional protection principle that does not rely on the traditional voltage transformer; S302, design and develop a protection equipment data interaction system based on carrier communication and 5G high-speed communication technology; S303, formulate a fault isolation strategy, including determining the criteria for fault isolation and the time sequence of isolation actions, integrating a fast fault handling mechanism in the protection device, and conducting tests.

8. The primary and secondary collaborative planning method based on a new power distribution system according to claim 6 is characterized in that: The implementation scheme of step S301, which does not rely on the single-ended directional protection principle of the traditional voltage transformer, is as follows: (1) Install high-sensitivity current and voltage sensors on one side of the DC line to detect transient traveling waves and current mutations Δi(t) and voltage mutations Δu(t); (2) Calculate the transient power ΔP(t) based on the detected current mutation Δi(t) and voltage mutation Δu(t): ΔP(t)=Δi(t)·Δu(t) Calculate the transient power energy E using the trapezoidal method of numerical integration P : (3) Determine the fault direction based on the calculated parameters: When the transient power energy E P >0, a reverse fault occurs; transient power energy E P When <0, a positive direction fault occurs. (4) Fault judgment criteria inside and outside the forward zone: Perform 6-scale wavelet decomposition on the fault current signal collected by the protection device, obtain the first-scale high-frequency energy E1 and the sixth-scale low-frequency energy E6, and define the ratio K of E1 to E6 P for: Where K is the proportionality coefficient, and the K value is selected by comprehensively considering the sampling frequency and the time window length; Whether it occurs in the protected area using the high-low frequency energy ratio K P As the criterion for protection action inside and outside the zone: when K P >K0, the fault occurs in the protection zone, otherwise it occurs outside the zone; if it is judged to be a fault in the zone, the protection action is immediately started, including disconnecting the faulty line and issuing an alarm signal; K0 is the protection action threshold, and K0 is taken as 1. (5) Assuming that the fault occurs between two monitoring points and the traveling wave propagates from the fault point to the two monitoring points, the detected traveling wave signal is analyzed using digital signal processing technology to extract the waveform, traveling wave velocity v, and the time difference Δt between the traveling wave and the two monitoring points; The following formula is used for analysis and calculation: where c is the speed of light in a vacuum, μ r is the relative magnetic permeability, ε r is the relative dielectric constant; Δt=t2-t1 Where t1 is the time when the traveling wave reaches monitoring point 1, and t2 is the time when the traveling wave reaches monitoring point 2; Define the fault location x, and calculate the fault location through the traveling wave velocity v and the time difference Δt when the traveling wave reaches the two monitoring points. The formula is as follows:

9. The primary and secondary collaborative planning method based on a new power distribution system according to claim 1 is characterized in that: The step S400 includes: S401, comprehensively analyze the impact of distributed renewable energy access on the primary system of the distribution network, including power flow distribution and voltage stability, and optimize the physical form and grid structure of the distribution network based on the analysis results; S402, configuring corresponding secondary protection devices according to the requirements of the adaptive protection mechanism and the rapid fault processing mechanism; S403, formulate a planning scheme for the coordinated work of the primary and secondary systems, including protection setting, communication protocol selection and data transmission path planning, and evaluate the planning scheme.

10. The primary and secondary collaborative planning method based on a new power distribution system according to claim 1 is characterized in that: The step S500 includes: S501: Install and debug equipment in the actual distribution network according to the planned solution, and conduct comprehensive system coordination; S502, monitor the actual operation of the system, collect and analyze the operation data, evaluate the effect of adaptive protection and rapid fault handling mechanism, and the effectiveness of primary and secondary system coordinated planning; S503: Optimize and adjust the system according to the evaluation result.

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