Low-voltage alternating current system configuration method and configuration device

Abstract

The invention discloses a low-voltage alternating-current system configuration method and device, and relates to the technical field of substation design, and the method comprises the steps: obtaining a loop information set of a low-voltage alternating-current system; the loop information set at least comprises each initial loop and a corresponding initial sensitivity value, a circuit breaker rated current, a cable length and a load; traversing the loop information set, and when the initial sensitivity value of at least one initial loop in the loop information set is smaller than the sensitivity threshold value, obtaining a third loop adjustment set by adopting the first method; when it is judged that all the third sensitivity values in the third loop adjustment set are larger than or equal to the sensitivity threshold value, important loops in all the loops are screened out, breakers of the important loops are configured as electronic tripping breakers, and an optimal configuration set is obtained; the optimal configuration set comprises all the configured loops. The low-voltage alternating current system adjusted based on the optimal configuration set is reasonable in configuration and high in efficiency, and the power supply reliability can be guaranteed.

Description

Technical Field

[0001] The present application generally relates to the technical field of substation design, and in particular to a low-voltage AC system configuration method and configuration device. Background Art

[0002] For residential electricity, there's a clear distinction between single-phase short circuits and ground faults at existing cable ends. Generally, ground resistance is greater, and the short-circuit current from a ground fault is smaller. However, in substations, due to the presence of the earth grid, the short-circuit currents from these two faults at the cable end are similar, with the ground fault current even greater. Therefore, substations can treat ground faults as single-phase short circuits. Therefore, both phase-to-zero and phase-to-ground short circuits at the cable end should be verified according to short-circuit fault requirements.

[0003] Existing substations typically have numerous circuits. When configuring the substation's low-voltage AC system, each circuit must meet established sensitivity and step-down coordination requirements. However, the actual conditions of each circuit vary, and how to configure each circuit (i.e., the low-voltage AC system) is a technical issue that needs to be urgently addressed. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desired to provide a low-voltage AC system configuration method and configuration device that are reasonably configured and highly efficient and ensure power supply reliability.

[0005] In a first aspect, the present application provides a low-voltage AC system configuration method, comprising the following steps: Acquire a loop information set of a low-voltage AC system; the loop information set includes at least: each initial loop and an initial sensitivity value, a circuit breaker rated current, a cable length, and a load corresponding to each initial loop; Traversing the loop information set, when there is an initial loop in the loop information set whose initial sensitivity value is less than the sensitivity threshold, obtaining a third loop adjustment set using the first method; the third loop adjustment set includes at least a plurality of third loops and a third sensitivity value corresponding to each third loop; When it is determined that all the third sensitivity values ​​in the third circuit adjustment set are greater than or equal to the sensitivity threshold, important circuits among all circuits are screened, and the circuit breakers of the important circuits are configured as electronic trip circuit breakers to obtain an optimal configuration set; the optimal configuration set includes all circuits that have been configured; the electronic trip circuit breaker has a shutdown instantaneous protection function.

[0006] According to the technical solution provided in the embodiment of the present application, after obtaining the third loop adjustment set, the following steps are further included: When it is determined that there is at least one third loop in the third loop adjustment set whose third sensitivity value is less than the sensitivity threshold, marking the third loop as a loop to be adjusted; All the circuits to be adjusted are equipped with cables with new cross-sectional specifications, the fourth sensitivity value of the circuit to be adjusted is recalculated, and the relationship between the fourth sensitivity value and the sensitivity threshold is compared again, until the fourth sensitivity values ​​of all the circuits to be adjusted are greater than or equal to the sensitivity threshold, and then the screening of important circuits among all circuits is performed.

[0007] According to the technical solution provided in the embodiment of the present application, the first method includes the following steps: Screening the initial loops whose initial sensitivity values ​​are less than a sensitivity threshold in the loop information set to obtain a target loop set; the target loop set at least includes: a plurality of target loops and an initial sensitivity value corresponding to each of the target loops; Filtering the target circuit set for circuits whose circuit breaker rated currents are greater than a current threshold, configuring the circuit breakers of these circuits to circuit breakers corresponding to the lower limits of the rated currents according to the lower limits of the rated currents, and calculating first sensitivity values ​​corresponding to these circuits to obtain a first circuit adjustment set; the first circuit adjustment set includes at least: a plurality of first circuits and a first sensitivity value corresponding to each first circuit; Screening the first circuit adjustment set for first circuits having a cable length greater than a set length or a load greater than a set load, configuring the circuit breakers of these first circuits as circuit breakers with zero-sequence protection, and calculating the second sensitivity values ​​corresponding to these first circuits to obtain a second circuit adjustment set; the second circuit adjustment set includes at least multiple second circuits and the second sensitivity value corresponding to each second circuit; When it is determined that the cable length in the second loop adjustment set is less than or equal to the set length and the load is less than or equal to the set load, calculating the single-phase short-circuit current corresponding to each second loop; Based on the single-phase short-circuit current and the sensitivity threshold, the short-time delay protection setting of the circuit breaker of the second circuit is determined and configured, and the third sensitivity value of the second circuit is calculated again to obtain a third circuit adjustment set; the third circuit adjustment set includes at least: multiple third circuits and the third sensitivity value corresponding to each third circuit.

[0008] According to the technical solution provided in the embodiment of the present application, the single-phase short-circuit current is calculated according to the following formula: ; in, is the single-phase short-circuit current, c is the voltage coefficient, is the line voltage of the low voltage AC system, is the phase-zero impedance of the low-voltage AC system, For station use variable resistor, For station transformer, is the cable resistance, Cable reactance.

[0009] According to the technical solution provided in the embodiment of the present application, the method further includes the following steps: Screen unimportant circuits from all circuits, and configure short-time delay protection for all of the unimportant circuits.

[0010] According to the technical solution provided in the embodiment of the present application, obtaining a loop information set of a low-voltage AC system specifically includes the following steps: Calling a loop database; the loop database includes multiple loop codes and corresponding loop data units, each of the loop data units includes at least a loop identifier, a circuit breaker model of the current loop, a cable length and load, and a cable cross section; The loop data unit corresponding to the current low-voltage AC system is searched in the loop database to generate the loop information set.

[0011] According to the technical solution provided in the embodiment of the present application, the following steps are also included: Determining whether data information of the same loop code in the optimal configuration set and in the loop database is consistent; If the data information is inconsistent, the loop database is updated according to the corresponding data information in the optimal configuration set, and an update log is generated.

[0012] According to the technical solution provided in the embodiment of the present application, the electronic trip circuit breaker is obtained according to the following method: A device parameter database is called and the corresponding electronic trip circuit breaker is searched in the device parameter database; the device parameter database includes at least the device types, device parameters, and quantities that can be provided by the current cooperative manufacturer or currently stored in the warehouse; the device types include at least electronic trip circuit breakers with instantaneous shutdown protection function and circuit breakers with zero-sequence protection.

[0013] According to the technical solution provided in the embodiment of the present application, the following steps are also included: When the quantity corresponding to any device type in the device parameter database is zero, replenishment information is generated and a prompt message is issued; the replenishment information at least includes the device type and device parameters.

[0014] In a second aspect, the present application provides a low-voltage AC system configuration device capable of implementing the above-mentioned low-voltage AC system configuration method, the device comprising: A data acquisition module is used to obtain a loop information set of a low-voltage AC system; the loop information set includes at least: each initial loop and the initial sensitivity value, circuit breaker rated current, cable length and load corresponding to each initial loop; A data processing module is configured to traverse the loop information set, and when there is at least one initial loop in the loop information set whose initial sensitivity value is less than a sensitivity threshold, obtain a third loop adjustment set using a first method; the third loop adjustment set includes at least multiple third loops and corresponding third sensitivity values; when it is determined that all the third sensitivity values ​​in the third loop adjustment set are greater than or equal to the sensitivity threshold, screen important loops among all loops, and configure the circuit breakers of the important loops as electronic trip circuit breakers to obtain an optimal configuration set; the optimal configuration set includes all loops that have been configured; the electronic trip circuit breaker has a shutdown instantaneous protection function.

[0015] It can be seen from the above technical solution that this application has at least the following beneficial effects: The present application discloses a low-voltage AC system configuration method, which includes: obtaining a loop information set of the low-voltage AC system; the loop information set includes at least: each initial loop and the initial sensitivity value corresponding to each initial loop, the rated current of the circuit breaker, the cable length and the load; traversing the loop information set, when there is at least one initial loop in the loop information set whose initial sensitivity value is less than a sensitivity threshold, using a first method to obtain a third loop adjustment set; the third loop adjustment set includes at least multiple third loops and corresponding third sensitivity values; when it is determined that all third sensitivity values ​​in the third loop adjustment set are greater than or equal to the sensitivity threshold, screening important loops in all loops, and configuring the circuit breakers of the important loops as electronic trip circuit breakers to obtain an optimal configuration set; the optimal configuration set includes all loops that have been configured; here, the electronic trip circuit breaker has a shutdown instantaneous protection function.

[0016] Compared with the low-voltage AC system of the traditional substation, which adopts a single method to configure the sensitivity and differential coordination of each circuit, the present application takes into account the different actual conditions of each circuit. By obtaining the circuit information set of the low-voltage AC system, traversing the circuit information set, when there is at least one initial circuit in the circuit information set whose initial sensitivity value is less than the sensitivity threshold, the first method is used to obtain the third circuit adjustment set, and then when it is judged that all the third sensitivity values ​​in the third circuit adjustment set are greater than or equal to the sensitivity threshold, the important circuits in all circuits are screened, and the circuit breakers of the important circuits are configured as electronic trip circuit breakers to obtain the optimal configuration set. That is: the initial sensitivity, lower limit of the rated current, cable length and load, single-phase short-circuit current, cable cross-section and important circuits of each circuit are screened and adjusted step by step, and the sensitivity of each circuit is continuously adjusted to meet the needs, and finally the optimal configuration set is obtained. The low-voltage AC system adjusted based on this optimal configuration set is not only reasonably configured and efficient, but also can ensure power supply reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Other features, objects and advantages of the present application will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings.

[0018] Figure 1 Flowchart of a method for configuring a low voltage AC system.

[0019] Figure 2 Flowchart of the first method.

[0020] Figure 3 Block diagram of the device configured for low voltage AC system.

[0021] Numbers in the figure: 1, data acquisition module; 2, data processing module. DETAILED DESCRIPTION

[0022] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.

[0023] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0024] To make the description of the following embodiments clear and concise, a brief introduction to the related technologies is first given: Substations are a crucial component of the power system, primarily responsible for voltage conversion, electrical energy transmission and distribution, and system control and protection. Substations contain a variety of electrical equipment and circuits, including both high-voltage and low-voltage equipment. The low-voltage AC system, part of a substation, primarily refers to the electrical system on the low-voltage side. This system typically refers to the lower-voltage AC power system within a substation, typically a three-phase AC system of 380V or less. This system typically provides power to industrial, commercial, and residential users.

[0025] A circuit is a closed path in a power system from the power source to the load, formed through switches and protective devices. In substations and low-voltage AC systems, circuits can include feeder circuits, busbar circuits, and distribution circuits. Each circuit in the low-voltage AC system distributes electrical energy, protects loads, and implements power control. The operating status of the low-voltage AC system directly affects the power supply of each circuit, which in turn provides feedback to the low-voltage AC system and, ultimately, the entire substation.

[0026] Under different application scenarios and requirements, the circuit configuration of the substation will be different. In order to make each circuit meet the established sensitivity requirements and differential matching requirements, it is urgent to study how to quickly configure each circuit (i.e., low-voltage AC system) to ensure power supply reliability.

[0027] In order to make the low voltage AC system configuration method provided in the embodiment of the present application clearer and easier to understand, the method is described below with reference to the accompanying drawings. Figure 1 As shown in FIG, this figure is a flow chart of a low-voltage AC system configuration method provided in an embodiment of the present application, the method comprising the following steps: S100. Acquire a loop information set of a low-voltage AC system; the loop information set includes at least: each initial loop and an initial sensitivity value corresponding to each initial loop, a circuit breaker rated current, a cable length, and a load.

[0028] Specifically, obtaining the loop information set of the low-voltage AC system includes the following steps: Calling a loop database; the loop database includes multiple loop codes and corresponding loop data units, each loop data unit including at least a loop identifier, a circuit breaker model of the current loop, a cable length and load, and a cable cross section; The loop data unit corresponding to the current low-voltage AC system is searched in the loop database to generate a loop information set.

[0029] It should be noted that the circuit database is shown in Table 1. The circuit identifier indicates whether a circuit is an important circuit. For example, "01" indicates an important circuit, and "02" indicates a non-important circuit. Important circuits here include the main transformer air cooling circuit, the power / lighting distribution box circuit, and the fan power supply for the main transformer intelligent control cabinet. Non-important circuits include the household outlets, lighting circuits, and water pump circuits in each compartment. "Xxxx" and "Yyyy" in Table 1 represent different circuit breaker models, "C1" and "C2" in Table 1 represent different cable lengths, "F1" and "F2" in Table 1 represent different loads, and "J1" and "J2" in Table 1 represent different cable cross-sections. These letters simply represent different data and do not have any relationship in size or order.

[0030] Here, Table 1 is only used as an example and is not intended to limit the present application. Actual data will form a loop database based on actual conditions.

[0031] Table 1 Circuit database

[0032] Among them, in the circuit information set: the initial circuit refers to the circuit directly obtained from the circuit database; the circuit breaker rated current can be obtained from the corresponding product manual based on different circuit breaker models; the cable length and load can also be directly obtained from the circuit database; The protection sensitivity of a low-voltage AC circuit breaker typically refers to its ability to respond to fault currents. Specifically, it determines whether the circuit breaker can promptly disconnect the circuit when the fault current reaches a certain value, thereby protecting the circuit and equipment from damage. Calculating protection sensitivity may involve multiple parameters, including the circuit breaker's rated current, trip current setting, and time-current characteristic curve.

[0033] That is, the initial sensitivity can be calculated based on the ratio of the operating current (tripping current) to the rated current, the time-current characteristic curve, or the ratio of the short-circuit current to the rated current.

[0034] The operating current refers to the minimum fault current at which a circuit breaker can operate (open), the rated current refers to the maximum normal operating current the circuit breaker can continuously carry, and the short-circuit current refers to the maximum expected short-circuit current the circuit breaker is required to open. The sensitivity of a circuit breaker can also be described by its time-current characteristic curve. This curve shows the circuit breaker's operating time for different fault currents. The higher the sensitivity, the shorter the circuit breaker's ability to open the circuit for smaller fault currents. Different circuit breaker types (such as C and D) have different time-current characteristic curves, and therefore, their protection sensitivity calculation methods and applications vary. In actual applications, the calculation and selection of protection sensitivity must be based on the specific electrical system parameters and circuit breaker specifications to ensure the appropriate level of protection. Other factors, such as load type, line length, and cable type, are often considered when designing and selecting a circuit breaker.

[0035] S200. Traverse the loop information set. When there is at least one initial loop in the loop information set whose initial sensitivity value is less than the sensitivity threshold, use the first method to obtain a third loop adjustment set; the third loop adjustment set includes at least multiple third loops and corresponding third sensitivity values.

[0036] It should be noted that the sensitivity threshold can be set according to actual needs.

[0037] like Figure 2 As shown, the first method includes the following steps: S201. Filter initial circuits whose initial sensitivity values ​​are less than a sensitivity threshold in a circuit information set to obtain a target circuit set; the target circuit set includes at least: multiple target circuits and an initial sensitivity value corresponding to each target circuit.

[0038] Among them, if the initial sensitivity value is greater than or equal to the sensitivity threshold, the corresponding initial loop does not need to be adjusted, and the current loop configuration is the optimal configuration solution.

[0039] Here, the target loop set refers to the loop set that does not meet the sensitivity requirement.

[0040] S202. Filter the target circuit set for circuits whose circuit breaker rated currents are greater than the current threshold, configure the circuit breakers of these circuits as circuit breakers corresponding to the lower limit values ​​of the rated currents according to the lower limit values ​​of the rated currents, and calculate the first sensitivity values ​​corresponding to these circuits to obtain a first circuit adjustment set; the first circuit adjustment set includes at least: multiple first circuits and a first sensitivity value corresponding to each first circuit.

[0041] The current threshold can be set according to actual needs. This solution takes into account the demand for future load increases and first determines whether the rated current of the current circuit breaker is appropriate.

[0042] Specifically, in the target circuit set, if the rated current of the circuit breaker is greater than the current threshold, it means that the current of the current target circuit is too large and needs to be replaced, that is, the circuit breakers of these circuits are configured as circuit breakers with the lower limit value corresponding to the corresponding rated current; and the first sensitivity values ​​corresponding to the circuits with these newly configured circuit breakers are calculated to obtain the first circuit adjustment set. Here, the calculation method of the first sensitivity value is the same as the calculation method of the initial sensitivity value and will not be repeated. Since the sensitivity value of the circuit changes after the circuit breaker is replaced, it is also necessary to verify other influencing factors, that is, execute step S203.

[0043] If the rated current of the circuit breaker of the circuit is less than or equal to the current threshold, it means that the current circuit breaker configuration of the target circuit meets the usage requirements and there is no need to replace the circuit breaker. The current circuit configuration is the optimal configuration solution.

[0044] S203. Filter first circuits in the first circuit adjustment set whose cable length is greater than a set length or whose load is greater than a set load, configure the circuit breakers of these first circuits as circuit breakers with zero-sequence protection, and calculate the second sensitivity values ​​corresponding to these first circuits to obtain a second circuit adjustment set; the second circuit adjustment set includes at least multiple second circuits and the second sensitivity value corresponding to each second circuit.

[0045] Among them, the set length and set load can be set according to actual needs.

[0046] In the first loop adjustment set, if the cable length of the loop is greater than the set length or the load is greater than the set load, it means that the current loop cannot solve the single-phase short-circuit sensitivity problem by adjusting the instantaneous or short-delay tripping current. This type of first loop needs to be replaced with a new circuit breaker, that is, the circuit breakers of these first loops are configured as circuit breakers with zero-sequence protection, and the second sensitivity values ​​corresponding to these first loops are calculated to obtain the second loop adjustment set. Here, the calculation method of the second sensitivity value is the same as the calculation method of the initial sensitivity value, and will not be repeated. Since the sensitivity value of the loop changes after the circuit breaker is replaced in this step, it is also necessary to verify other influencing factors, that is, execute step S204.

[0047] In addition, a circuit breaker with zero-sequence protection refers to an electronic trip circuit breaker with ground protection or a thermal-magnetic circuit breaker plus a zero-sequence module, where the zero-sequence module refers to a zero-sequence CT + current relay + shunt release.

[0048] If the cable length of the loop is less than or equal to the set length and the load is less than or equal to the set load, the corresponding initial loop does not need to be adjusted and the current loop configuration is the optimal configuration solution.

[0049] S204: When it is determined that the cable length in the second circuit adjustment set is less than or equal to the set length and the load is less than or equal to the set load, calculate the single-phase short-circuit current corresponding to each second circuit.

[0050] The single-phase short-circuit current is calculated according to the following formula: ; in, is the single-phase short-circuit current, c is the voltage coefficient, is the line voltage of the low voltage AC system, is the phase-zero impedance of the low-voltage AC system, For station use variable resistor, For station transformer, is the cable resistance, Cable reactance.

[0051] S205. Determine and configure the short-time delay protection setting of the circuit breaker of the second circuit based on the single-phase short-circuit current and the sensitivity threshold, and recalculate the third sensitivity value of the second circuit to obtain a third circuit adjustment set; the third circuit adjustment set includes at least: multiple third circuits and the third sensitivity value corresponding to each third circuit.

[0052] It should be noted that the short-time delay protection setting is calculated according to the following formula: ; in, It is the short-time delay protection setting value. It is the overload long-time protection setting value. For time.

[0053] S300. When it is determined that all third sensitivity values ​​in the third circuit adjustment set are greater than or equal to the sensitivity threshold, important circuits among all circuits are screened, and the circuit breakers of the important circuits are configured as electronic trip circuit breakers to obtain an optimal configuration set; the optimal configuration set includes all circuits that have been configured; the electronic trip circuit breaker has a shutdown instantaneous protection function.

[0054] It's important to note that the circuit breakers used in the third circuit adjustment set obtained in the preceding steps already have short-delay protection. However, their instantaneous protection cannot be disabled, and the instantaneous protection setting is twice the short-delay protection setting. This can easily cause the three-phase short-circuit current at the lower-level head end of most short cable circuits to exceed the instantaneous protection setting of the upper-level circuit breaker, resulting in an over-tripping phenomenon. Therefore, it's necessary to screen important circuits and replace their circuit breakers to address this issue.

[0055] The electronic trip circuit breaker is obtained according to the following method: Call the device parameter database and search for the corresponding electronic trip circuit breaker in the device parameter database; the device parameter database at least includes the device types, device parameters, and quantities that can be provided by the current cooperative manufacturer or stored in the current warehouse; the device types at least include electronic trip circuit breakers with instantaneous shutdown protection function and circuit breakers with zero-sequence protection.

[0056] By replacing the circuit breakers of important circuits with electronic trip circuit breakers with instantaneous shutdown protection function, the coordination problem of the upper and lower levels can be ensured by relying on the time difference.

[0057] Here, the device parameter database is shown in Table 2. "M1," "M2," and so on in Table 2 represent specific parameters of different circuit breakers, such as model and function; "Q1," "Q2," and so on in Table 2 represent different quantities. Furthermore, these letters simply represent different parameters or values ​​and have no relationship of size or order.

[0058] Table 2 Device parameter database

[0059] In addition, the method further comprises the following steps: When the quantity corresponding to any device type in the device parameter database is zero, replenishment information is generated and a prompt message is issued; the replenishment information includes at least the device type and device parameters.

[0060] Among them, when the quantity of a device in the device parameter database is zero, it means that the device is out of stock in the device parameter database and needs to be replenished as soon as possible, that is, replenishment information is generated, and prompt information is used to remind staff to replenish the stock.

[0061] Furthermore, after obtaining the third loop adjustment set, the following steps are also included: When it is determined that there is at least one third loop in the third loop adjustment set whose third sensitivity value is less than the sensitivity threshold, marking the third loop as a loop to be adjusted; All circuits to be adjusted are equipped with cables with new cross-sectional specifications, the fourth sensitivity value of the circuit to be adjusted is recalculated, and the relationship between the fourth sensitivity value and the sensitivity threshold is compared again until the fourth sensitivity values ​​of all circuits to be adjusted are greater than or equal to the sensitivity threshold, and then the important circuits among all circuits are screened.

[0062] It should be noted that if the third sensitivity value of at least one third loop in the third loop adjustment set is less than the sensitivity threshold, it indicates that there are still loops that do not meet the requirements. These loops are marked as loops to be adjusted, and cables with new cross-sectional specifications are reconfigured for all loops to be adjusted. The fourth sensitivity value of the loop to be adjusted is then recalculated, and the fourth sensitivity value is again compared with the sensitivity threshold until the fourth sensitivity values ​​of all loops to be adjusted are greater than or equal to the sensitivity threshold, and step S300 is then executed. Here, the cable with new cross-sectional specifications refers to a cable with a larger cross-sectional area than the current cable.

[0063] Furthermore, the method further comprises the following steps: Filter out unimportant circuits from all circuits and configure short-time delay protection for all unimportant circuits.

[0064] Among them, short-delay protection is configured for all unimportant circuits, and different short-delay times are set for each level of switch to ensure that the lower level acts first and the upper level acts later, that is, the time difference is relied upon to ensure the coordination of the upper and lower levels.

[0065] Furthermore, the method further comprises the following steps: Determine whether the data information of the same loop code in the optimal configuration set and in the loop database is consistent; If the data information is inconsistent, the loop database is updated according to the corresponding data information in the optimal configuration set, and an update log is generated.

[0066] It should be noted that after the above steps, the low-voltage AC system has an optimal configuration. The data corresponding to each circuit will change accordingly. If the final optimal configuration set is inconsistent with certain data in the circuit database, the corresponding circuit (circuit data unit) will need to be updated. For example, the display interface for generating the configuration plan includes a touch panel. Under normal circumstances, the circuit code boxes corresponding to each circuit in the low-voltage AC system are all green. After the optimal configuration set is obtained based on the above steps, if the optimal configuration set is inconsistent with the data in the circuit database, the corresponding circuit code box on the display interface will turn red, indicating that the circuit requires a configuration update. If the optimal configuration set is consistent with the data in the circuit database, the corresponding circuit code box on the display interface will turn green, indicating that the circuit does not need to be updated. Clicking the red circuit code box on the touch panel will update the data in the corresponding circuit data unit and generate an update log. This update log records the updates to the circuit database for subsequent tracking and improvement.

[0067] This application also provides a low-voltage AC system configuration device, which can implement the above-mentioned low-voltage AC system configuration method, such as Figure 3 As shown, the device includes: Data acquisition module 1 is used to obtain a loop information set of the low-voltage AC system; the loop information set includes at least: each initial loop and the initial sensitivity value corresponding to each initial loop, the rated current of the circuit breaker, the cable length and the load; Data processing module 2 is configured to traverse the loop information set and, when there is at least one initial loop in the loop information set whose initial sensitivity value is less than the sensitivity threshold, obtain a third loop adjustment set using the first method; the third loop adjustment set includes at least a plurality of third loops and corresponding third sensitivity values; When it is determined that all third sensitivity values ​​in the third circuit adjustment set are greater than or equal to the sensitivity threshold, important circuits among all circuits are screened, and the circuit breakers of the important circuits are configured as electronic trip circuit breakers to obtain the optimal configuration set; the optimal configuration set includes all circuits that have been configured; the electronic trip circuit breaker has a shutdown instantaneous protection function.

[0068] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention herein is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features having similar functions disclosed in this application.

Claims

1. A low voltage AC system configuration method, characterized in that: The following steps are involved: Acquire a loop information set of a low voltage AC system; the loop information set includes at least: each initial loop and an initial sensitivity value, a circuit breaker rated current, a cable length and a load corresponding to each initial loop; Traversing the loop information set, when there is at least one initial loop in the loop information set whose initial sensitivity value is less than the sensitivity threshold, adopting the first method to obtain a third loop adjustment set; the third loop adjustment set at least includes a plurality of third loops and corresponding third sensitivity values; When it is determined that all the third sensitivity values ​​in the third circuit adjustment set are greater than or equal to the sensitivity threshold, important circuits among all circuits are screened, and the circuit breakers of the important circuits are configured as electronic trip circuit breakers to obtain an optimal configuration set; the optimal configuration set includes all circuits that have been configured; the electronic trip circuit breaker has a function of shutting down instantaneous protection.

2. A low voltage AC system configuration method according to claim 1, characterized in that: After obtaining the third loop adjustment set, the following steps are also included: When it is determined that there is at least one third loop in the third loop adjustment set whose third sensitivity value is less than the sensitivity threshold, marking the third loop as a loop to be adjusted; All the circuits to be adjusted are equipped with cables with new cross-sectional specifications, the fourth sensitivity values ​​of the circuits to be adjusted are recalculated, and the fourth sensitivity value is compared with the sensitivity threshold again, until the fourth sensitivity values ​​of all the circuits to be adjusted are greater than or equal to the sensitivity threshold, and then the screening of important circuits among all circuits is performed.

3. A low voltage AC system configuration method according to claim 1, characterized in that: The first method comprises the following steps: Screening the initial loops whose initial sensitivity values ​​are less than the sensitivity threshold in the loop information set to obtain a target loop set; the target loop set at least includes: a plurality of target loops and an initial sensitivity value corresponding to each of the target loops; Screening the circuits in the target circuit set whose circuit breaker rated current is greater than the current threshold, configuring the circuit breakers of these circuits as circuit breakers corresponding to the lower limit values ​​of the corresponding rated currents according to the lower limit values ​​of the rated currents, and calculating the first sensitivity values ​​corresponding to these circuits to obtain a first circuit adjustment set; the first circuit adjustment set at least includes: a plurality of first circuits and a first sensitivity value corresponding to each first circuit; Screening the first circuits in the first circuit adjustment set, the first circuits having a cable length greater than a set length or a load greater than a set load, configuring the circuit breakers of these first circuits as circuit breakers with zero-sequence protection, and calculating the second sensitivity values ​​corresponding to these first circuits to obtain a second circuit adjustment set; the second circuit adjustment set at least includes a plurality of second circuits and a second sensitivity value corresponding to each second circuit; When it is determined that the cable length in the second loop adjustment set is less than or equal to the set length and the load is less than or equal to the set load, calculating the single-phase short-circuit current corresponding to each second loop; According to the single-phase short-circuit current and the sensitivity threshold, the short-delay protection setting of the circuit breaker of the second circuit is determined and configured, and the third sensitivity value of the second circuit is calculated again to obtain a third circuit adjustment set; the third circuit adjustment set includes at least: multiple third circuits and the third sensitivity value corresponding to each third circuit.

4. A low voltage AC system configuration method according to claim 3, characterized in that: The single-phase short-circuit current is calculated according to the following formula: ； in, is the single-phase short-circuit current, c is the voltage coefficient, is the line voltage of the low voltage AC system, is the phase-zero impedance of the low voltage AC system, For station use variable resistor, For station transformer, is the cable resistance, Cable reactance.

5. A low voltage AC system configuration method according to claim 1, characterized in that: The method further comprises the following steps: Screen unimportant circuits from among all circuits, and configure short-time delay protection for all of the unimportant circuits.

6. A low voltage AC system configuration method according to claim 1, characterized in that: Get the loop information set of the low voltage AC system, specifically The following steps are involved: Calling a loop database; the loop database includes a plurality of loop codes and corresponding loop data units, each of the loop data units includes at least a loop identifier, a circuit breaker model of the current loop, a cable length and load, and a cable cross section; The loop data unit corresponding to the current low-voltage AC system is searched in the loop database to generate the loop information set.

7. A low voltage AC system configuration method according to claim 6, characterized in that: The following steps are also included: Determine whether data information of the same loop code in the optimal configuration set and in the loop database is consistent; If the data information is inconsistent, the loop database is updated according to the corresponding data information in the optimal configuration set, and an update log is generated.

8. A low voltage AC system configuration method according to claim 1, characterized in that: The electronic trip circuit breaker is obtained according to the following method: Calling a device parameter database, and searching the device parameter database for the corresponding electronic trip circuit breaker; The device parameter database includes at least the device types, device parameters, and quantities that can be provided by the current cooperative manufacturer or stored in the current warehouse; the device types include at least electronic trip circuit breakers with instantaneous protection shutdown function and circuit breakers with zero-sequence protection.

9. A low voltage AC system configuration method according to claim 8, characterized in that: The following steps are also included: When the quantity corresponding to any device type in the device parameter database is zero, replenishment information is generated and a prompt message is issued; the replenishment information at least includes the device type and device parameters.

10. A low voltage AC system configuration device, capable of implementing a low voltage AC system configuration method according to any one of claims 1 to 9, characterized in that: The device comprises: A data acquisition module, used to obtain a loop information set of a low voltage AC system; the loop information set includes at least: each initial loop and an initial sensitivity value corresponding to each initial loop, a circuit breaker rated current, a cable length and a load; A data processing module is used to traverse the loop information set, and when there is at least one initial loop in the loop information set whose initial sensitivity value is less than the sensitivity threshold, adopt the first method to obtain a third loop adjustment set; the third loop adjustment set includes at least multiple third loops and corresponding third sensitivity values; when it is judged that all the third sensitivity values ​​in the third loop adjustment set are greater than or equal to the sensitivity threshold, screen important loops in all loops, and configure the circuit breakers of the important loops as electronic trip circuit breakers to obtain an optimal configuration set; the optimal configuration set includes all loops that have been configured; the electronic trip circuit breaker has a function of shutting down instantaneous protection.

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