Self-adaptive protection parameter setting method and device for low-voltage circuit breaker and computer readable storage medium

Abstract

The invention discloses a self-adaptive protection parameter setting method and device for a low-voltage circuit breaker and a computer readable storage medium, and the method comprises the steps: S1, recording the load current data of the low-voltage circuit breaker in a preset time period every day after the load current of the low-voltage circuit breaker is initialized and put into operation, and carrying out the phase-splitting storage; s2, respectively calculating three-phase load current root-mean-square values at a preset moment; and S3, setting an overload long-time-delay tripping setting current value corresponding to the maximum value in the three-phase load current root-mean-square values according to a preset corresponding relation between the load current and an overload long-time-delay tripping setting current model. According to the method, the low-voltage circuit breaker can be dynamically adjusted according to the real-time load current condition by adopting a protection parameter self-adaptive adjustment mode, so that the protection accuracy is improved, and the probability of misoperation and rejection is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution equipment control, and in particular to a method and device for setting adaptive protection parameters of a low-voltage circuit breaker, and a computer-readable storage medium. Background Art

[0002] Currently, low-voltage circuit breaker overload protection is one of the core functions of low-voltage circuit breakers, which can protect the line and the equipment on the line, as well as the safety of people. Its core function is to detect the current of the line passing through the low-voltage circuit breaker, and trip when the current threshold and time threshold are met, so that the line is de-energized to achieve protection.

[0003] The current national standard GB / T22710-2008 7.5 requires that the protection characteristics of the basic protection functions of the controller, as long as the constants customized by the manufacturer are within the range. Different choices of this constant between manufacturers will correspond to different protection curve values. This constant has been solidified when the low-voltage circuit breaker leaves the factory. It is not flexible after leaving the factory. The setting value selection can be configured on site but cannot be automatically configured. Therefore, the overload protection of the low-voltage circuit breaker is often not accurate enough, resulting in frequent false trips and refusal to operate on site. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method, device and computer-readable storage medium for setting adaptive protection parameters of a low-voltage circuit breaker, so as to avoid mismatch between the protection curve and the actual load caused by the fixed parameters of the low-voltage circuit breaker, thereby causing false operation and refusal of protection.

[0005] In order to solve the above technical problems, the present invention provides a method for setting adaptive protection parameters of a low voltage circuit breaker, comprising:

[0006] Step S1, after the load current of the low-voltage circuit breaker is initialized and put into operation, the load current data of the low-voltage circuit breaker in a preset time period every day is recorded and saved in phases;

[0007] Step S2, calculating the root mean square value of the three-phase load current at a preset time;

[0008] Step S3, according to the preset corresponding relationship between the load current and the overload long-delay tripping setting current model, setting the overload long-delay tripping setting current value corresponding to the maximum value of the three-phase load current root mean square value.

[0009] Preferably, the method further comprises: performing protection parameter modeling according to the load of the line where the low-voltage circuit breaker is located, and downloading the model to the low-voltage circuit breaker, and adaptively setting the protection parameters of the low-voltage circuit breaker through load model matching;

[0010] Initialize the model as follows:

[0011]

[0012] Where, I is the load current, I R is the set current value, t R For setting time.

[0013] Preferably, in step S1, the preset time period per day is specifically 15 minutes.

[0014] Preferably, the step S2 specifically includes:

[0015] Determine whether the preset time has been reached. If reached, calculate the RMS value of the three-phase load current according to the following formula:

[0016]

[0017]

[0018]

[0019] In the above formula, Ia' is the RMS current value of the A phase load for 15 minutes, Ib' is the RMS current value of the B phase load for 15 minutes, Ic' is the RMS current value of the C phase load for 15 minutes, and N is the number of load current data recorded in a preset time period.

[0020] Preferably, the preset time is 0 hours and 0 minutes.

[0021] Preferably, the step S3 specifically includes:

[0022] Compare the calculated 15-minute three-phase load current root mean square value I′ a ,I b ′、I c ′, take the three-phase maximum value Imax, Imax=max(I′ a ,I b ′,I c ′);

[0023] According to the preset load current and overload long-time delay tripping setting current model correspondence table, set the overload long-time delay tripping setting current I corresponding to Imax by looking up the table. R value.

[0024] The present invention also provides a low voltage circuit breaker adaptive protection parameter setting device, comprising:

[0025] The data recording module is used to record the load current data of the low-voltage circuit breaker in a preset time period every day after the load current of the low-voltage circuit breaker is initialized and put into operation, and save it in phases;

[0026] A calculation module, used for respectively calculating the root mean square value of the three-phase load current saved by the data recording module at a preset time;

[0027] The parameter setting module is used to set the overload long-delay tripping setting current value corresponding to the maximum value of the three-phase load current root mean square value according to the preset corresponding relationship between the load current and the overload long-delay tripping setting current model.

[0028] The present invention also provides a computer-readable storage medium, which includes a stored computer program; wherein, when the computer program is running, it controls the device where the computer-readable storage medium is located to execute the method for setting the adaptive protection parameters of the low-voltage circuit breaker.

[0029] The implementation of the present invention has the following beneficial effects: First, by adopting the method of adaptive adjustment of protection parameters, the low-voltage circuit breaker can be dynamically adjusted according to the real-time load current conditions, thereby improving the accuracy of protection and reducing the probability of false operation and refusal to operate. Secondly, using daily load data as a basis for judgment can more truly reflect the actual working state of the low-voltage circuit breaker, providing a more reliable basis for parameter setting. Furthermore, by establishing a model relationship between daily load data and the overload long-delay tripping setting current value, the scientific and systematic parameter setting is achieved, and the setting efficiency and accuracy are improved. Finally, by reducing the protection trigger time, the present invention can respond to overload conditions more quickly and effectively protect the safe operation of lines and equipment. The present invention has significant advantages and practical value in improving the protection performance of low-voltage circuit breakers, improving system stability, and ensuring the safe operation of power equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] 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 description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 The present invention is a flowchart of a method for setting adaptive protection parameters of a low-voltage circuit breaker according to an embodiment of the present invention.

[0032] Figure 2 It is a specific flow chart of a method for setting adaptive protection parameters of a low-voltage circuit breaker according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following descriptions of the embodiments refer to the accompanying drawings to illustrate specific embodiments in which the present invention may be implemented.

[0034] Please refer to Figure 1 As shown, the first embodiment of the present invention provides a method for setting parameters of a low-voltage circuit breaker adaptive protection, comprising:

[0035] Step S1, after the load current of the low-voltage circuit breaker is initialized and put into operation, the load current data of the low-voltage circuit breaker in a preset time period every day is recorded and saved in phases;

[0036] Step S2, calculating the root mean square value of the three-phase load current at a preset time;

[0037] Step S3, according to the preset corresponding relationship between the load current and the overload long-delay tripping setting current model, setting the overload long-delay tripping setting current value corresponding to the maximum value of the three-phase load current root mean square value.

[0038] Specifically, please combine Figure 2 As shown, the embodiment of the present invention performs protection parameter modeling according to the load of the line where the low-voltage circuit breaker is located, and installs the model to the low-voltage circuit breaker. The protection parameters of the low-voltage circuit breaker are adaptively adjusted through load model matching, ensuring that the protection parameters of the low-voltage circuit breaker can be adaptively adjusted as the line load changes, thereby achieving accurate protection.

[0039] Initialize the model as follows:

[0040]

[0041] Where I is the load current and the setting value I R (Unit: A) The value range is (0.4~1.0)×In, and the setting time is t R (Unit: s) The value range is 1s to 18s. Assume t R = 15s Establish the corresponding relationship table between load current I and overload long-time delay tripping setting current model as shown in Table 1 below:

[0042] Table 1 Correspondence table between load current and overload long-time delay tripping setting current model

[0043]

[0044] Step S1 initializes the load current of the low-voltage circuit breaker, specifically, the load current I=In, where In is the rated current. Then the low-voltage circuit breaker is put into operation. The load current data for 15 minutes every day is recorded and saved in phases. Assume that the three-phase current data for 15 minutes every day is:

[0045] Ia[N], N=[0,1,……95]

[0046] Ib[N], N=[0,1,……95]

[0047] Ic[N], N=[0,1,……95]

[0048] In the above formula, Ia[N] is the load current data array of phase A for 15 minutes in one day, Ib[N] is the load current data array of phase B for 15 minutes in one day, and Ic[N] is the load current data array of phase C for 15 minutes in one day.

[0049] Step S2 first determines whether the preset time has been reached. Taking 0:00 as an example, if it has reached 0:00, the three-phase load current root mean square value is calculated according to the following formula:

[0050]

[0051]

[0052]

[0053] In the above formula, Ia' is the RMS current value of phase A load for 15 minutes, Ib' is the RMS current value of phase B load for 15 minutes, Ic' is the RMS current value of phase C load for 15 minutes, and N is the number of load current data recorded in a preset time period (e.g., 15 minutes).

[0054] Next, in step S3, the calculated 15-minute three-phase load current root mean square value I′ is compared with a ,I b ′、I c ′, take the maximum value of the three phases, which is defined as Imax, that is, Imax=max(I′ a ,I b ′,I c ′). According to the preset load current and overload long-delay tripping setting current model correspondence table shown in Table 1 above, the overload long-delay tripping setting current I corresponding to Imax is set by, for example, looking up the table. R Value, for example: Imax=0.65In, then set I R =0.6×In.

[0055] The present invention significantly improves the protection accuracy of the field operation of the low-voltage circuit breaker by optimizing the protection parameter setting method, thereby effectively reducing the probability of false operation and refusal to operate. Specifically, in the traditional setting method, when t R When set to 15s, if the commonly used parameter setting method is used, I R The value is usually set to 1.0. Taking the load current of 225A as an example, under this condition, the action time of the overload long-time delay protection is as long as 666.7s.

[0056] However, after adopting the adaptive protection parameter setting method proposed in the present invention, I can be set more accurately according to the actual load current situation. R At the same load current of 225A and t R Under the condition of 15s, according to the method of the present invention, I R The value is set to 0.9. This slight adjustment brings a significant effect: the action time of the overload long-delay protection is shortened to 540s. This significant time reduction proves the effectiveness of the present invention in improving the protection performance and response speed of low-voltage circuit breakers. In this way, it is possible to ensure that the low-voltage circuit breaker responds to overload conditions in a shorter time, thereby more reliably protecting the safe operation of the line and equipment.

[0057] The innovation of the present invention is mainly reflected in the following aspects:

[0058] First, the strategy of adaptive adjustment of protection parameters is innovatively adopted. This strategy realizes dynamic and adaptive adjustment of protection parameters under the premise of complying with the basic protection function requirements of GB / T22710-2008 7.5 controller. This adjustment method enables low-voltage circuit breakers to provide corresponding protection more accurately according to real-time system requirements.

[0059] Secondly, the present invention uniquely uses daily load data as the basis for adjusting protection parameters. By analyzing the size of the daily load data, the overload long-delay tripping setting current I that matches it is set. R This protection parameter setting method driven by actual load data significantly improves the adaptability and accuracy of low-voltage circuit breakers in practical applications.

[0060] Finally, the present invention also innovatively establishes the daily load data and the overload long-delay tripping setting current I R The model relationship between the values. Through this model, we can more systematically and scientifically understand and predict the optimal protection parameters required by low-voltage circuit breakers under different daily load conditions. This model not only improves the design efficiency, but also provides strong support for the intelligent and adaptive development of low-voltage circuit breakers.

[0061] Corresponding to the method for setting parameters of a low-voltage circuit breaker adaptive protection according to the first embodiment of the present invention, the second embodiment of the present invention further provides a device for setting parameters of a low-voltage circuit breaker adaptive protection, including:

[0062] The data recording module is used to record the load current data of the low-voltage circuit breaker in a preset time period every day after the load current of the low-voltage circuit breaker is initialized and put into operation, and save it in phases;

[0063] A calculation module, used for respectively calculating the root mean square value of the three-phase load current saved by the data recording module at a preset time;

[0064] The parameter setting module is used to set the overload long-delay tripping setting current value corresponding to the maximum value of the three-phase load current root mean square value according to the preset corresponding relationship between the load current and the overload long-delay tripping setting current model.

[0065] Corresponding to the low-voltage circuit breaker adaptive protection parameter setting method of the aforementioned embodiment 1 of the present invention, the third embodiment of the present invention also provides a computer-readable storage medium, and the computer-readable storage medium includes a stored computer program; wherein, when the computer program is running, it controls the device where the computer-readable storage medium is located to execute the low-voltage circuit breaker adaptive protection parameter setting method.

[0066] Preferably, the computer program can be divided into one or more modules / units (such as computer program 1, computer program 2, ...), and the one or more modules / units are stored in the memory and executed by the processor to complete the present invention. The one or more modules / units can be a series of computer program instruction segments that can complete specific functions, and the instruction segments are used to describe the execution process of the computer program in the device.

[0067] The processor may be a central processing unit (CPU), or other general-purpose processors, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor, or the processor may be any conventional processor. The processor is the control center of the device, and various parts of the device are connected using various interfaces and lines.

[0068] The memory mainly includes a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function, etc., and the data storage area can store related data, etc. In addition, the memory can be a high-speed random access memory, or a non-volatile memory, such as a plug-in hard disk, a smart memory card (SmartMedia Card, SMC), a secure digital (Secure Digital, SD) card, and a flash card (Flash Card), etc., or the memory can also be other volatile solid-state storage devices.

[0069] It should be noted that the above-mentioned device may include but is not limited to a processor and a memory, which can be understood by those skilled in the art.

[0070] Regarding the working principle and process of the above embodiment, please refer to the description of the above embodiment 1 of the present invention, which will not be repeated here.

[0071] It can be seen from the above description that compared with the prior art, the beneficial effects brought by the embodiments of the present invention are: first, by adopting the method of adaptive adjustment of protection parameters, the low-voltage circuit breaker can be dynamically adjusted according to the real-time load current situation, thereby improving the accuracy of protection and reducing the probability of false operation and refusal to operate. Secondly, using daily load data as a basis for judgment can more truly reflect the actual working state of the low-voltage circuit breaker, providing a more reliable basis for parameter setting. Furthermore, by establishing a model relationship between daily load data and the overload long-delay tripping setting current value, the scientific and systematic parameter setting is achieved, and the setting efficiency and accuracy are improved. Finally, by reducing the protection trigger time, the present invention can respond to overload conditions more quickly and effectively protect the safe operation of lines and equipment. The present invention has significant advantages and practical value in improving the protection performance of low-voltage circuit breakers, improving system stability, and ensuring the safe operation of power equipment.

[0072] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for setting adaptive protection parameters of a low voltage circuit breaker, characterized in that: include: Step S1, after the load current of the low-voltage circuit breaker is initialized and put into operation, the load current data of the low-voltage circuit breaker in a preset time period every day is recorded and saved in phases; Step S2, calculating the root mean square value of the three-phase load current at a preset time; Step S3, according to the preset corresponding relationship between the load current and the overload long-delay tripping setting current model, setting the overload long-delay tripping setting current value corresponding to the maximum value of the three-phase load current root mean square value.

2. The method according to claim 1, characterized in that Also includes: The protection parameter model is built according to the load of the line where the low-voltage circuit breaker is located, and the model is downloaded to the low-voltage circuit breaker. The protection parameters of the low-voltage circuit breaker are adaptively set through load model matching; Initialize the model as follows: Where, I is the load current, I R is the set current value, t R For setting time.

3. The method according to claim 1, characterized in that In step S1, the preset time period each day is specifically 15 minutes.

4. The method according to claim 3, characterized in that The step S2 specifically includes: Determine whether the preset time has been reached. If reached, calculate the RMS value of the three-phase load current according to the following formula: In the above formula, Ia' is the RMS current value of the A phase load for 15 minutes, Ib' is the RMS current value of the B phase load for 15 minutes, Ic' is the RMS current value of the C phase load for 15 minutes, and N is the number of load current data recorded in a preset time period.

5. The method according to claim 4, characterized in that The preset time is specifically 0 hours and 0 minutes.

6. The method according to claim 4, characterized in that The step S3 specifically includes: Compare the calculated 15-minute three-phase load current root mean square value I′ a , I′ b , I′ c The size of the three-phase maximum value Imax is taken, Imax=max(I′ a ,I′ b ,I′ c ); According to the preset load current and overload long-time delay tripping setting current model correspondence table, set the overload long-time delay tripping setting current I corresponding to Imax by looking up the table. R value.

7. A low voltage circuit breaker adaptive protection parameter setting device, characterized in that: include: The data recording module is used to record the load current data of the low-voltage circuit breaker in a preset time period every day after the load current of the low-voltage circuit breaker is initialized and put into operation, and save it in phases; A calculation module, used for respectively calculating the root mean square value of the three-phase load current saved by the data recording module at a preset time; The parameter setting module is used to set the overload long-delay tripping setting current value corresponding to the maximum value of the three-phase load current root mean square value according to the preset corresponding relationship between the load current and the overload long-delay tripping setting current model.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program; wherein, when the computer program is run, it controls the device where the computer-readable storage medium is located to execute the method for setting the adaptive protection parameters of a low-voltage circuit breaker according to any one of claims 1 to 6.

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