Reliability improvement method and system for flexible direct current protection function, medium and program product
By segmenting the protection action of the flexible DC protection system and associating the respective input conditions, outputting independent protection action signals and exit signals, the problem of failure to meet any condition in the prior art causes all segments to exit, and the protection is achieved Accurate exit of functions and normal operation of the system.
Patent Information
- Application Number
- CN202411058698.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-02
- Publication Date
- 2024-12-17
AI Technical Summary
When any condition is not met, all segmented protection functions will be withdrawn, affecting the normal operation of the system.
The protection actions with the same protection function are divided into segments, and each protection action is associated with its corresponding input conditions. By outputting each protection action signal and exit signal, the independent exit of each protection action is achieved to avoid accidentally withdrawing the protection function. The specific method includes inputting the protection action signal into three-to-two logic for judgment, so as to distinguish and output the protection exit signal.
The precise exit of each section of protection actions is achieved, the accidental withdrawal protection function is avoided, and the normal operation of the DC protection system is ensured.
Smart Images
Figure CN119154227A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of direct current protection, and in particular relates to a method, system, medium and program product for improving the reliability of a flexible direct current protection function. Background Art
[0002] The overall function flow of the flexible DC protection system is to collect analog signals and obtain the protection exit through analog calculation. However, the analog signals contain all operating modes and all measurement point signals of each protection function, and there is a risk of erroneous exit of different operating modes or different protection functions. The existing flexible DC protection system, whether it is current protection, voltage protection or differential protection, considers the following segmentation methods: 1. System operating status; 2. Collecting analog measurement signals; 3. Switching signals associated with the protection. However, these conditions are currently designed for the entire protection operation and withdrawal design, and there is a defect that if any condition is not met, all segments of the entire protection function will be exited. Taking the DC low voltage protection function as an example, the same unlocking signal is associated with the first and second protection sections. When the unlocking signal disappears, both protection sections exit, resulting in the DC protection system not being able to operate normally. Specifically, Figure 1 shown. Summary of the invention
[0003] The purpose of the present invention is to provide a method, system, medium and program product for improving the reliability of flexible DC protection function, so as to solve the problem that any condition of the protection input and output design in the prior art is not met, resulting in the output of different sections of protection action, affecting the normal operation of the DC protection system.
[0004] In order to solve the above technical problems, the present invention provides a method for improving the reliability of flexible direct current protection function, the method comprising: dividing the protection action of the same protection function into segments, associating the protection action of each segment with the protection input condition corresponding to each segment, so as to output the protection action signal corresponding to each segment according to the protection input condition corresponding to each segment; and then for a certain protection action, outputting the protection output signal of the segment according to the protection action signal of the segment.
[0005] Furthermore, outputting the protection exit signal of the section according to the protection action signal of the section specifically involves inputting the protection action signals output by the three protection systems into a two-out-of-three logic to determine and output the protection exit signal.
[0006] Furthermore, the protection functions include current protection, low voltage protection and differential protection.
[0007] Furthermore, when the protection function is a low voltage protection function, the protection action is divided into low voltage protection action stage I and low voltage protection action stage II; the protection input conditions associated with low voltage protection action stage I include low voltage conditions, protection input pressure plate conditions, low voltage protection action stage I analog quantity measurement conditions and unlock input conditions, and the low voltage protection action stage I analog quantity measurement conditions include no measurement fault of the positive line voltage and no measurement fault of the negative line voltage; the low voltage condition is Among them U set is the voltage setting value, Udp is the positive line voltage, and Udn is the negative line voltage; the protection input conditions associated with the low voltage protection action II stage include overcurrent conditions, low voltage conditions, protection input pressure plate conditions and low voltage protection action II stage analog measurement conditions. The low voltage protection action II stage analog measurement conditions include no measurement fault of the positive line voltage, no measurement fault of the negative line voltage, no measurement fault of the positive line current and no measurement fault of the negative line current. The overcurrent conditions include Idp>I set or Idn>I set , where I set is the current setting value, Idn is the negative line current, and Idp is the positive line current.
[0008] Furthermore, when the protection function is an overcurrent protection function, the protection action is divided into overcurrent protection action section I and overcurrent protection action section II; the protection input conditions associated with the overcurrent protection action section I include the protection input pressure plate condition, the transformer valve side current has no measurement fault, the converter current has no measurement fault and the overcurrent protection action section I current effective value condition, and the overcurrent protection action section I current effective value condition is specifically that the transformer valve side current effective value or the converter current effective value is greater than the maximum value of the transformer valve side current effective value section I protection setting and the converter current effective value section I protection setting; the protection input conditions associated with the overcurrent protection action section II include the protection input pressure plate condition, the transformer valve side current has no measurement fault, the converter current has no measurement fault and the overcurrent protection action section II current effective value condition, and the overcurrent protection action section II current effective value condition is specifically that the transformer valve side current effective value or the converter current effective value is greater than the maximum value of the transformer valve side current effective value section II protection setting and the converter current effective value section II protection setting.
[0009] Furthermore, when the protection function is a differential protection function, the protection action is divided into differential protection action section I and differential protection action section II; the protection input conditions associated with differential protection action section I include the protection pressure plate condition, no measurement fault on the transformer valve side current, no measurement fault on the converter current and the effective value condition of the differential protection action section I, and the effective value condition of the differential protection action section I is specifically that the effective value of the differential current is greater than the maximum value of the current section I braking value and the current section I setting value; the protection input conditions associated with differential protection action section II include the protection pressure plate condition, no measurement fault on the transformer valve side current, no measurement fault on the converter current and the effective value condition of the differential protection action section II, and the effective value condition of the differential protection action section II is specifically that the effective value of the differential current is greater than the maximum value of the current section II braking value and the current section II setting value.
[0010] In order to solve the above technical problem, the present invention further provides a computer system, including a processor, and the processor is used to execute a computer program to implement the steps of a method for improving the reliability of a flexible direct current protection function.
[0011] In order to solve the above technical problem, the present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method for improving the reliability of the flexible direct current protection function are implemented.
[0012] In order to solve the above technical problem, the present invention also provides a computer program product, including a computer program, which implements the steps of the method for improving the reliability of the flexible direct current protection function when the computer program is executed by a processor.
[0013] The beneficial effects of the above technical scheme are as follows: the present invention is an improved invention, which divides the protection action of the same protection function into segments, and each segment of the protection action is associated with the protection output condition corresponding to each segment to output the corresponding protection action signal, and outputs the corresponding protection exit signal of each segment according to the protection action signal of each segment, thereby distinguishing the protection exit signal of each segment in the protection function, realizing the independence of each segment of the protection action, and being able to exit the corresponding protection action segment when the input conditions of each segment are not met, realizing accurate protection function exit and avoiding wrong exit of the protection function, and solving the problem that any condition of the protection investment and withdrawal design in the prior art is not met, resulting in the exit of different segments of the protection action, affecting the normal operation of the protection exit function. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Figure 1 It is a low voltage protection schematic diagram of the prior art;
[0015] Figure 2 It is a schematic diagram of low voltage protection segmentation association conditions of an embodiment of a method for improving the reliability of a flexible direct current protection function of the present invention;
[0016] Figure 3It is a schematic diagram of a low voltage segmented protection outlet signal of an embodiment of a method for improving the reliability of a flexible direct current protection function of the present invention;
[0017] Figure 4 It is a schematic diagram of overcurrent protection segmentation association conditions of an embodiment of a method for improving the reliability of a flexible direct current protection function of the present invention;
[0018] Figure 5 It is a schematic diagram of differential protection segment association conditions in an embodiment of the method for improving the reliability of the flexible direct current protection function of the present invention. DETAILED DESCRIPTION
[0019] The focus of the present invention is to provide a method for improving the reliability of flexible direct current protection function, which includes: segmenting the protection action of the same protection function, associating the protection action of each segment with the protection input conditions corresponding to each segment, so as to output the protection action signals corresponding to each segment according to the protection input conditions corresponding to each segment; and then for a certain protection action, output the protection exit signal of the segment according to the protection action signal of the segment. The present invention divides the protection action of the same protection function into segments, associates the protection action of each segment with the protection output conditions corresponding to each segment to output the corresponding protection action signal, and outputs the corresponding protection exit signals of each segment according to the protection action signal of each segment, thereby distinguishing the protection exit signals of each segment in the protection function, realizing the independence of each segment protection action, and being able to exit the corresponding protection action segment when the input conditions of each segment are not met, realizing accurate protection function exit to avoid erroneous exit of the protection function, and solving the problem that any condition of the protection throw-in and throw-out design in the prior art is not met, resulting in the exit of different segments of the protection action, affecting the normal operation of the protection exit function.
[0020] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.
[0021] Embodiment of the method for improving the reliability of the flexible DC protection function:
[0022] The present embodiment provides a method for improving the reliability of a flexible direct current protection function, the method comprising: dividing the protection action of the same protection function into segments, associating the protection action of each segment with the protection input conditions corresponding to each segment, so as to output the protection action signals corresponding to each segment according to the protection input conditions corresponding to each segment; and then for a certain segment of protection action, outputting the protection exit signal of the segment according to the protection action signal of the segment. Specifically, outputting the protection exit signal of the segment according to the protection action signal of the segment is to input the protection action signals output by the three protection systems into a two-out-of-three logic to judge and output the protection exit signal. By performing a two-out-of-three logic judgment on the protection action signals output by the three protection systems, it is possible to avoid the situation where an error occurs in a single protection system, resulting in the wrong exit of the protection action signal.
[0023] Among them, different protection functions include current protection, low voltage protection and differential protection. When the protection function is low voltage protection function, the protection action is divided into low voltage protection action stage I and low voltage protection action stage II; the protection input conditions associated with low voltage protection action stage I include low voltage conditions, protection input pressure plate conditions, low voltage protection action stage I analog measurement conditions and unlock input conditions, and the low voltage protection action stage I analog measurement conditions include no measurement fault of positive line voltage and no measurement fault of negative line voltage; the low voltage conditions are Among them U set is the voltage setting value, Udp is the positive line voltage, and Udn is the negative line voltage; the protection input conditions associated with the low voltage protection action II stage include overcurrent conditions, low voltage conditions, protection input pressure plate conditions and low voltage protection action II stage analog measurement conditions. The low voltage protection action II stage analog measurement conditions include no measurement fault of the positive line voltage, no measurement fault of the negative line voltage, no measurement fault of the positive line current and no measurement fault of the negative line current. The overcurrent conditions include Idp>I set or Idn>I set , where I set is the current setting value, Idn is the negative line current, and Idp is the positive line current. By refining the protection input conditions, the protection action is segmented into low voltage protection action section I and low voltage protection action section II, and they are associated with different protection input conditions, so as to achieve accurate exit of different operating modes or different sections of protection functions. Among them, the protection pressure plate is a soft button for input and output set in the protection software. It is generally not used and is only used during maintenance and debugging. Unlocking and input: Unlocking refers to the operating state. The analog quantity used by some protections will only reach the rated value in the operating state. When the analog quantity is not the rated value in the operating state, it proves that a fault has occurred. Specifically, Figure 2 shown.
[0024] When the protection function is the overcurrent protection function, the protection action is divided into overcurrent protection action stage I and overcurrent protection action stage II; the protection input conditions associated with the overcurrent protection action stage I include the protection input pressure plate condition, the transformer valve side current IVY has no measurement fault, the converter current IVC has no measurement fault and the overcurrent protection action stage I current effective value condition. The overcurrent protection action stage I current effective value condition is specifically that the transformer valve side current effective value IVY_RMS or the converter current effective value IVC_RMS is greater than the transformer valve side current effective value I protection setting IVY_RMS1 and the converter current effective value I protection setting IVY_RMS1 is greater than the converter current effective value I protection setting IVY_RMS2. The maximum value of the protection setting IVC_RMS1; the protection input conditions associated with the overcurrent protection action stage II include the protection input pressure plate condition, the transformer valve side current IVY has no measurement fault, the converter current IVC has no measurement fault and the overcurrent protection action stage II current effective value condition. The overcurrent protection action stage II current effective value condition is specifically that the transformer valve side current effective value IVY_RMS or the converter current effective value IVC_RMS is greater than the maximum value of the transformer valve side current effective value II protection setting IVY_RMS2 and the converter current effective value II protection setting IVC_RMS2. Among them, the transformer valve side current effective value IVY_RMS and the converter current effective value IVC_RMS are obtained by full-cycle Fourier transform of the transformer valve side current and the converter current. Specifically, Figure 5 shown.
[0025] When the protection function is a differential protection function, the protection action is divided into differential protection action section I and differential protection action section II; the protection input conditions associated with differential protection action section I include the protection pressure plate condition, the transformer valve side current IVY has no measurement fault, the converter current IVC has no measurement fault and the differential protection action section I current effective value condition, and the differential protection action section I current effective value condition is specifically that the differential current effective value I_RMS is greater than the maximum value of the current section I braking value I_RES1 and the current section I setting value I_SET1; the protection input conditions associated with differential protection action section II include the protection pressure plate condition, the transformer valve side current has no measurement fault, the converter current has no measurement fault and the differential protection action section II current effective value condition, and the differential protection action section II current effective value condition is specifically that the differential current effective value I_RMS is greater than the maximum value of the current section II braking value I_RES2 and the current section II setting value I_SET2. Among them, the differential current effective value I_RMS is specifically obtained by subjecting the transformer valve side current IVY and the converter current IVC to full-cycle Fourier transformation to obtain the imaginary part and real part of the transformer valve side current IVY and the converter current, calculating the difference between the imaginary part of the transformer valve side current and the converter current and the difference between the real part of the transformer valve side current and the converter current IVC, and calculating the differential current effective value I_RMS by the difference between the imaginary part of the transformer valve side current IVY and the converter current IVC and the difference between the real part of the transformer valve side current IVY and the converter current IVC. The current I segment braking value I_RES1 and the current II segment braking value I_RES2 are current braking values set according to the actual needs of differential protection, and the current I segment setting value I_SET1 and the current II segment setting value I_SET2 are current setting values set according to the actual needs of differential protection. The current braking value I_RES is the maximum value of the transformer valve side current effective value IVY_RMS and the converter current effective value IVC_RMS. The transformer valve side current effective value IVY_RMS and the converter current effective value IVC_RMS are obtained by full-cycle Fourier transform of the transformer valve side current IVY and the converter current IVC. Figure 4 shown.
[0026] The specific implementation method is to transmit the protection action signals of each protection action of the same protection logic of the protection host (such as DC low voltage protection action stage I, DC low voltage protection action stage II) to the three-out-of-two device respectively, and implement the three-out-of-two logic judgment of the protection action signals of the three protection systems, namely, the DC low voltage protection action stage I of the A protection system, the DC low voltage protection action stage I of the B protection system, and the DC low voltage protection action stage I of the C protection system in a three-out-of-two logic judgment device, and then output the protection exit signal to prevent the mis-exit of protection caused by the mixed judgment of the DC low voltage protection action stage I of the A protection system and the DC low voltage protection action stage II of the A protection system, thereby ensuring the normal operation of the DC protection system. Specifically, Figure 3 shown.
[0027] The present invention outputs protection exit signals of different segments for the protection action of the same protection function in segments and associates different input conditions. When the input conditions disappear, the corresponding protection action segments are exited, thereby achieving accurate protection function exit and avoiding erroneous exit of the protection function, and solving the problem in the prior art that different segments of the protection action are exited when a certain condition is not met.
[0028] Computer System Embodiment:
[0029] The present invention also provides a computer system, including a processor, which executes a computer program to implement the steps of the method for improving the reliability of the flexible direct current protection function. The specific process, principle and effect have been described in detail in the embodiment of the method for improving the reliability of the flexible direct current protection function, and will not be repeated here.
[0030] Computer readable storage medium embodiment:
[0031] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for improving the reliability of the flexible direct current protection function are implemented. The specific process, principle and effect have been described in detail in the embodiment of the method for improving the reliability of the flexible direct current protection function, and will not be repeated here.
[0032] Computer program product embodiment:
[0033] The present invention also provides a computer program product, including a computer program, which implements the steps of the method for improving the reliability of the flexible direct current protection function when executed by a processor. The specific process, principle and effect have been described in detail in the embodiment of the method for improving the reliability of the flexible direct current protection function, and will not be repeated here.
[0034] Specific implementation methods are given above, but the present invention is not limited to the described implementation methods. The basic idea of the present invention lies in the above basic scheme. For ordinary technicians in this field, it does not take creative work to design various deformed models, formulas, and parameters according to the teachings of the present invention. Changes, modifications, substitutions, and variations of the implementation methods without departing from the principles and spirit of the present invention still fall within the scope of protection of the present invention.
Claims
1. A method for improving the reliability of flexible DC protection function, characterized in that: The method includes: dividing the protection actions of the same protection function into segments, associating the protection actions of each segment with the protection input conditions corresponding to each segment, so as to output the protection action signals corresponding to each segment according to the protection input conditions corresponding to each segment; and then for a certain protection action, outputting the protection exit signal of the segment according to the protection action signal of the segment.
2. The method for improving the reliability of flexible direct current protection function according to claim 1, characterized in that: Outputting the protection exit signal of the section according to the protection action signal of the section specifically involves inputting the protection action signals output by the three protection systems into a three-out-of-two logic to perform judgment and output the protection exit signal.
3. The method for improving the reliability of flexible DC protection function according to claim 1, characterized in that: The protection functions include overcurrent protection, low voltage protection and differential protection.
4. The method for improving the reliability of flexible direct current protection function according to claim 3, characterized in that: When the protection function is a low voltage protection function, the protection action is divided into low voltage protection action stage I and low voltage protection action stage II; the protection input conditions associated with low voltage protection action stage I include low voltage conditions, protection input pressure plate conditions, low voltage protection action stage I analog quantity measurement conditions and unlock input conditions, and the low voltage protection action stage I analog quantity measurement conditions include no measurement fault of the positive line voltage and no measurement fault of the negative line voltage; the low voltage conditions are Among them U set is the voltage setting value, Udp is the positive line voltage, and Udn is the negative line voltage; the protection input conditions associated with the low voltage protection action II stage include overcurrent conditions, low voltage conditions, protection input pressure plate conditions and low voltage protection action II stage analog quantity measurement conditions, the low voltage protection action II stage analog quantity measurement conditions include positive line voltage without measurement fault, negative line voltage without measurement fault, positive line current without measurement fault and negative line current without measurement fault, and the overcurrent conditions include Idp>I set or Idn>I set , where I set is the current setting value, Idn is the negative line current, and Idp is the positive line current.
5. The method for improving the reliability of flexible DC protection function according to claim 3, characterized in that: When the protection function is an overcurrent protection function, the protection action is divided into overcurrent protection action section I and overcurrent protection action section II; the protection input conditions associated with the overcurrent protection action section I include the protection input pressure plate condition, the transformer valve side current has no measurement fault, the converter current has no measurement fault and the overcurrent protection action section I current effective value condition, and the overcurrent protection action section I current effective value condition is specifically that the transformer valve side current effective value or the converter current effective value is greater than the maximum value of the transformer valve side current effective value section I protection setting and the converter current effective value section I protection setting; the protection input conditions associated with the overcurrent protection action section II include the protection input pressure plate condition, the transformer valve side current has no measurement fault, the converter current has no measurement fault and the overcurrent protection action section II current effective value condition, and the overcurrent protection action section II current effective value condition is specifically that the transformer valve side current effective value or the converter current effective value is greater than the maximum value of the transformer valve side current effective value section II protection setting and the converter current effective value section II protection setting.
6. The method for improving the reliability of flexible direct current protection function according to claim 3, characterized in that: When the protection function is a differential protection function, the protection action is divided into differential protection action section I and differential protection action section II; the protection input conditions associated with differential protection action section I include the protection pressure plate condition, no measurement fault on the transformer valve side current, no measurement fault on the converter current and the effective value condition of the differential protection action section I, and the effective value condition of the differential protection action section I is specifically that the effective value of the differential current is greater than the maximum value of the current section I braking value and the current section I setting value; the protection input conditions associated with differential protection action section II include the protection pressure plate condition, no measurement fault on the transformer valve side current, no measurement fault on the converter current and the effective value condition of the differential protection action section II, and the effective value condition of the differential protection action section II is specifically that the effective value of the differential current is greater than the maximum value of the current section II braking value and the current section II setting value.
7. A computer system comprising a processor, characterized in that: The processor is used to execute a computer program to implement the steps of the method for improving the reliability of a flexible direct current protection function as claimed in any one of claims 1 to 6.
8. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for improving the reliability of the flexible direct current protection function as claimed in any one of claims 1 to 6 are implemented.
9. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method for improving the reliability of the flexible direct current protection function as claimed in any one of claims 1 to 6 are implemented.