Electric energy quality measurement and analysis method and device for traction network protection setting

Abstract

The invention discloses a traction network protection setting-oriented electric energy quality measurement and analysis method and device, and relates to the technical field of electric energy quality measurement. The method comprises the steps of obtaining electrical quantity information of a traction network in real time; performing analog-to-digital conversion on the electrical quantity information to obtain an electrical quantity data sequence; determining harmonic suppression parameters according to the electrical quantity data sequence; and adjusting a protection setting value of the traction network based on the harmonic suppression parameter. The problem that an existing traction network electric energy quality measurement and analysis technology is difficult to meet the measurement and analysis requirements of a novel AC-DC-AC type electric locomotive traction network is solved. The technical effects of high measurement stability and accurate analysis result in the traction network protection setting electric energy quality measurement and analysis process are realized.

Description

Technical Field

[0001] The present application relates to the technical field of power quality measurement, and in particular to a method and device for power quality measurement and analysis for traction network protection setting. Background Art

[0002] The electric drive system of traditional AC-DC electric locomotives mainly relies on thyristors to control the voltage on the DC side. However, when thyristors control voltage, the current will generate a large number of low-order harmonics, which will not only affect the stable operation of the railway power grid, but also cause certain damage to the electric locomotive itself and other equipment.

[0003] The new AC-DC-AC electric locomotive adopts a more complex control system, the most critical of which is the four-quadrant rectifier based on transient direct current control and the four-quadrant inverter based on direct torque control or space voltage vector control. The new AC-DC-AC electric locomotive has significant advantages over the traditional AC-DC electric locomotive. It has greater traction power, can meet the operation requirements of higher speed and greater load, and the power factor of the locomotive is significantly improved. The low-order harmonic current generated by the new AC-DC-AC electric locomotive is significantly reduced, but it still contains more high-order harmonics, and the harmonic content increases during starting, traction and braking. In recent years, due to the immature development of traction network power quality monitoring and analysis technology, traction network accidents caused by excessive harmonic content have occurred from time to time. Therefore, it is of great significance to study the power quality measurement and analysis system for traction network protection setting. Summary of the invention

[0004] The embodiment of the present application provides a method and device for measuring and analyzing power quality for traction network protection setting, thereby solving the problem that the existing traction network power quality measurement and analysis technology is difficult to meet the measurement and analysis requirements of the new AC-DC-AC type electric locomotive traction network. The technical effect of high measurement stability and accurate analysis results in the process of measuring and analyzing power quality for traction network protection setting is achieved.

[0005] In a first aspect, an embodiment of the present application provides a method for measuring and analyzing power quality for traction network protection setting, comprising: acquiring electrical quantity information of the traction network in real time; performing analog-to-digital conversion on the electrical quantity information to obtain an electrical quantity data sequence; determining harmonic suppression parameters based on the electrical quantity data sequence; and adjusting the protection setting value of the traction network based on the harmonic suppression parameters.

[0006] In combination with the first aspect, in a possible implementation, the electrical quantity information includes current information, voltage information, phase angle, power and harmonic content of the traction network; and the electrical quantity data sequence includes current data and voltage data.

[0007] In combination with the first aspect, in a second possible implementation method, the real-time acquisition of electrical quantity information of the traction network includes: sampling the continuous signal on the traction network at equal time intervals based on multiple sampling points to obtain key signal features; amplifying and filtering the key signal features to obtain the electrical quantity information.

[0008] In combination with the first aspect, in a third possible implementation method, the analog-to-digital conversion of the electrical quantity information to obtain an electrical quantity data sequence includes: analog-to-digital conversion of the electrical quantity information to obtain a switching quantity signal; and continuous sampling of the switching quantity signal at equal time intervals to obtain the electrical quantity data sequence.

[0009] In combination with the third possible implementation manner of the first aspect, in a fourth possible implementation manner, determining the harmonic suppression parameter according to the electrical quantity data sequence includes: performing data analysis on the electrical quantity data sequence based on a simplified fast Fourier transform to obtain each harmonic content; and determining the harmonic suppression parameter based on the each harmonic content; wherein the simplified fast Fourier transform is as follows: in, Wherein, F(k) represents the simplified fast Fourier transform function, N represents the total number of elements in the electrical quantity data sequence, n represents the logical address of the element in the electrical quantity data sequence, y represents the element in the electrical quantity data sequence, 2y represents the even sequence point, i.e., the element with an even logical address in the electrical quantity data sequence, 2y+1 represents the odd sequence point, i.e., the element with an odd logical address in the electrical quantity data sequence, f(n) represents the periodic discrete time function signal, f1(y) is the periodic discrete time function signal of the even sequence point, f2(y) is the periodic discrete time function signal of the odd sequence point, F1(k) represents the simplified fast Fourier transform function of the even sequence point in the electrical quantity data sequence, F2(k) represents the simplified fast Fourier transform function of the odd sequence point in the electrical quantity data sequence, e is a natural base, j represents a complex number, k represents the logical address of the element in the electrical quantity data sequence in the simplified fast Fourier transform function, k=0,1,...,N-1.

[0010] In combination with the first aspect, in a fifth possible implementation, after obtaining the electrical quantity data sequence, it also includes: constructing a spectrum analysis diagram of the traction network based on the electrical quantity data sequence to display the harmonic distribution of the traction network.

[0011] In the second aspect, an embodiment of the present application provides a device for measuring and analyzing power quality for traction network protection setting, including: a data acquisition module, used to collect electrical quantity information of the traction network, and convert the electrical quantity information into a switch signal to obtain an electrical quantity data sequence; a communication module, used to realize data transmission between various modules; a data processing module, used to receive and process the electrical quantity data sequence, and determine harmonic suppression parameters based on the electrical quantity data sequence, and generate a spectrum analysis diagram for display.

[0012] In conjunction with the second aspect, in a possible implementation, the data acquisition module includes: an electrical quantity acquisition component, used to perform equal time interval sampling on the traction network based on multiple sampling points to obtain key signal features; a data preprocessing unit, used to perform signal amplification and filtering processing on the key signal features to obtain the electrical quantity information;

[0013] The analog-to-digital conversion unit is used to perform analog-to-digital conversion on the electrical quantity information to obtain a switch quantity signal, and continuously sample the switch quantity signal at equal time intervals to obtain the electrical quantity data sequence.

[0014] In combination with the second aspect, in a second possible implementation method, the data processing module includes: a data receiving unit, used to receive the electrical quantity data sequence uploaded by the data acquisition module; a data analysis unit, used to perform data analysis on the electrical quantity data sequence to obtain the harmonic content of each order of the traction network, and determine the harmonic suppression parameter based on the harmonic content of each order; a data storage unit, used to store the electrical quantity information of the traction network, the electrical quantity data sequence, the harmonic suppression parameter and the protection setting value.

[0015] In combination with the second possible implementation manner of the second aspect, in a third possible implementation manner, the data processing module further includes a visualization unit for generating a spectrum analysis diagram based on the electrical quantity data sequence, and displaying the spectrum analysis diagram to a user in a visual manner.

[0016] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0017] This application obtains the electrical quantity information of the traction network in real time through multiple sampling points, meeting the real-time requirements in the process of measuring the power quality of the traction network. After that, the electrical quantity information is preprocessed and converted into analog to digital, and the electrical quantity data sequence is obtained. The simplified fast Fourier transform function is obtained through the discrete Fourier transform function, and the electrical quantity data sequence is analyzed based on the simplified fast Fourier transform function, which simplifies the analysis process of the electrical quantity data sequence in the traditional mode and realizes a faster, more stable and more efficient data analysis process.

[0018] This application determines harmonic suppression parameters by analyzing electrical data sequences, and obtains protection setting values ​​for the traction network based on the harmonic suppression parameters. This effectively solves the problem of immature development of monitoring and analysis technologies for railway traction networks in the prior art, thereby achieving high efficiency and stable process in the measurement and analysis of power quality for traction networks. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 A flow chart of a method for measuring and analyzing power quality for traction network protection setting provided in an embodiment of the present application;

[0021] Figure 2 A schematic diagram of the principle of a system for measuring and analyzing power quality for traction network protection setting provided in an embodiment of the present application;

[0022] Figure 3 A schematic diagram of the usage status of the power quality measurement and analysis method and device for traction network protection setting provided in an embodiment of the present application. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] like Figure 1 As shown, the embodiment of the present application provides a method for measuring and analyzing power quality for traction network protection setting, the method comprising:

[0025] Step 101: Acquire the electrical quantity information of the traction network in real time.

[0026] On the one hand, the continuous signal on the traction network is sampled at equal time intervals by relying on multiple sampling points to obtain the continuous signal of the traction network and the key characteristics of the signal.

[0027] The sampling method of multiple sampling points on the traction network is continuous and time-equally spaced sampling, which ensures the consistency of the key features of the signal in time, that is, the time difference between the key features of the signal is fixed. This consistency helps the subsequent data processing and analysis process, making the results after processing and analysis more reliable. At the same time, due to the fixed sampling time interval, it is easier to predict the location of future sampling points, so as to better plan the process of data collection and analysis.

[0028] Moreover, continuous sampling can more completely preserve the continuous change information of the key features of the signal on the time axis, which is particularly important for applications that require high time resolution. Under equal time interval sampling, due to the uniform distribution of sampling points, the overall characteristics and local details of the key features of the signal can be better reflected, reducing the errors caused by uneven sampling intervals.

[0029] On the other hand, after obtaining the key features of the signal, it is necessary to amplify and filter the key features of the signal to obtain the electrical quantity information required subsequently.

[0030] The key features of the signals obtained by the multi-channel sampling points are the key features of the signals without any processing. They need to be amplified, filtered and other data processing operations to improve the data quality, reduce the difficulty of data analysis and enhance the data interpretability. Specifically include:

[0031] Amplify the key features of the signal at a certain ratio to observe or analyze the trends and details of the data more clearly. This operation requires the use of an electronic device called an amplifier.

[0032] Data filtering is an operation to filter out specific band frequencies in a signal, which is an important measure to suppress and prevent interference. Filtering is divided into two types: classical filtering and modern filtering. In the embodiment of the present application, data filtering uses modern filtering.

[0033] Exemplarily, the electrical quantity information includes, but is not limited to, current information, voltage information, phase angle, power, and harmonic content of the traction grid.

[0034] Step 102: Perform analog-to-digital conversion on the electrical quantity information to obtain an electrical quantity data sequence.

[0035] In the embodiment of the present application, the electrical quantity information is converted into a switch quantity signal, and the switch quantity signal is sampled at equal time intervals to obtain an electrical quantity data sequence.

[0036] After obtaining the electrical quantity data sequence, it also includes:

[0037] A spectrum analysis diagram of the traction network is constructed based on the electrical quantity data sequence to show the harmonic distribution of the traction network.

[0038] Exemplarily, the electrical quantity data sequence proposed in the embodiment of the present application includes current data and voltage data of the traction network.

[0039] Step 103: Determine harmonic suppression parameters according to the electrical quantity data sequence.

[0040] Including: by simplifying the discrete Fourier transform, a simplified fast Fourier transform is obtained, as follows:

[0041] Discrete Fourier transform is the core of determining harmonic suppression parameters according to the electrical quantity data sequence described in the embodiment of the present application, and realizes the mapping of the electrical quantity data sequence between the time domain and the frequency domain.

[0042] The Fourier transform of a periodic discrete time function signal f(n) is called the discrete Fourier transform (DFT) and can be expressed as follows:

[0043]

[0044] Wherein, F'(k) represents the Fourier transform function of the periodic discrete time function signal, N represents the total number of sequences, n represents the logical address of the elements in the sequence, n∈N, j represents a complex number, f(n) represents the periodic discrete time function signal, e is the natural base, k is the logical address of the element in the sequence in the Fourier transform function, k=0,1,2,...,N-1.

[0045] Through the above discrete Fourier transform function, it can be known that in the embodiment of the present application, when the electrical quantity information is sampled in the time domain, its frequency domain representation will undergo periodic extension. When the electrical quantity data sequence is represented as a periodic spectrum in the time domain, it will be represented as a discrete spectrum in the frequency domain.

[0046] The discrete Fourier series in the periodic sequence can be expressed as follows:

[0047]

[0048] in, for An alternative way to write The discrete Fourier series representing a periodic sequence, DFS is used to analyze periodic signals, and in the embodiment of the present application refers to the discrete Fourier series used to analyze the electrical quantity data sequence, represents a discrete time function signal of a periodic sequence, and IDFS represents the inverse discrete Fourier series.

[0049] After analysis, it can be found that when processing a sequence with an infinite period, in fact all its important information can be compressed and included in the total number of sequences N within a period. Therefore, the analysis methods and tools for finite-length sequences can also be applied to sequences with infinite periods. The discrete Fourier series (DFS) is used to analyze periodic signals, but in the embodiments of the present application, when this period is regarded as a finite-length sequence, the discrete Fourier series (DFS) can be regarded as the discrete Fourier transform (DFT) of the finite-length sequence. The discrete Fourier transform (DFT) of the finite-length sequence is a special case of the discrete Fourier series (DFS) under specific conditions, which is completely suitable for the analysis of finite-length sequences. It can be expressed as follows:

[0050]

[0051] Here, IDFT stands for Inverse Discrete Fourier Transform.

[0052] In practical applications, the discrete Fourier transform (DFT) has a large amount of calculation, which makes it difficult to realize the real-time calculation of electrical quantity information in the traction network, limiting its application. Therefore, a fast Fourier transform (FFT) method is introduced to simplify the calculation process of the discrete Fourier transform. The fast Fourier transform is divided into two categories: time extraction method (DIT-FFT) and frequency extraction method (DIP-FFT). Taking the time extraction method (DIT-FFT) as an example, the principle of fast Fourier transform is analyzed:

[0053] Suppose there is a finite length sequence with N=2 points L , where L is an integer. The sequence f(n) (n=0, 1, ..., N-1) is first divided into two groups according to the parity of n, namely f(2y)=f 1 (y), f(2y+1)=f 2 (y), y = 0, 1, ... (N / 2) - 1. Among them, f (2y) represents the function value composed of the number of calculation sequences in the sequence where n is an even number, with f 1 f(2y+1) represents the function value of the number of calculation sequences in the sequence where n is an odd number, expressed as f 2 (y) indicates that y indicates n after grouping.

[0054] Then the discrete Fourier transform (DFT) can be decomposed into two parts as follows.

[0055]

[0056] Among them, F'1(k) and F'2(k) are both discrete Fourier transforms of N / 2 points, F'1(k) is the discrete Fourier transform of even sequence points, and F'2(k) is the discrete Fourier transform of odd sequence points.

[0057] Only F'1(k) and F'2(k) need to be found, k = 0, 1, ..., N / 2-1, and all F'(k) values ​​in the interval k = 0, 1, ..., N can be obtained, thereby reducing the amount of discrete Fourier transform (DFT) calculation, reducing the calculation difficulty, and improving the efficiency and speed of the calculation.

[0058] In the embodiment of the present application, in the discrete Fourier transform process, it is first necessary to obtain a fast Fourier transform through a discrete Fourier transform, and then simplify the fast Fourier transform to obtain a simplified fast Fourier transform, wherein the simplification process of the fast Fourier transform is as follows:

[0059]

[0060] in, In the formula, F(k) represents the simplified fast discrete Fourier transform function, N represents the total number of sequences, that is, the total number of elements in the electrical quantity data sequence in the embodiment of the present application, n represents the logical address of the element in the electrical quantity data sequence, n∈N, y is the element in the electrical quantity data sequence, 2y represents the even sequence point, that is, the element with an even logical address in the electrical quantity data sequence, 2y+1 represents the odd sequence point, that is, the element with an odd logical address in the electrical quantity data sequence, f(n) represents the periodic discrete time function signal, f1(y) is the periodic discrete time function signal of the even sequence point, f2(y) is the periodic discrete time function signal of the odd sequence point, F1(k) represents the simplified fast Fourier transform function of the even sequence point in the electrical quantity data sequence, F2(k) represents the simplified fast Fourier transform function of the odd sequence point in the electrical quantity data sequence, k represents the logical address of the element in the digital signal sequence in the simplified fast Fourier transform function, k=0,1,...,N-1.

[0061] Based on the simplified fast Fourier transform, the electrical quantity data sequence is analyzed to obtain the harmonic content of the traction network.

[0062] Based on the content of each harmonic, the harmonic suppression parameters are determined.

[0063] Specifically, the calculation process of the harmonic suppression parameters is as follows.

[0064] The fundamental current, 2nd harmonic, 3rd harmonic, 5th harmonic and 7th harmonic of the traction network are calculated by simplified fast Fourier transform, and the harmonic suppression parameters are calculated based on the above current values:

[0065]

[0066] Among them, K hIt represents the harmonic suppression parameter, I1 represents the effective value of the fundamental current of the locomotive load, I2, I3, I5 and I7 represent the effective value of the 2nd harmonic current, the effective value of the 3rd harmonic current, the effective value of the 5th harmonic current and the effective value of the 7th harmonic current of the locomotive load respectively.

[0067] Step 104: Adjust the protection setting value of the traction network based on the harmonic suppression parameters.

[0068] It should be noted that the protection setting value of the traction network includes the traction network protection resistor setting value and the traction network protection reactance setting value.

[0069] Specifically, take the calculation of the distance protection setting value of the traction network as an example. The calculation process is as follows:

[0070]

[0071] Among them, R set Represents the setting value of the traction network distance protection resistor, X set Represents the setting value of the traction network distance protection reactance. L,min is the minimum load impedance, is the load impedance angle, K is the line impedance angle. When the load is at its maximum, the voltage at the protection installation is the lowest. The impedance measured at this time is the minimum load impedance. rel is the reliability coefficient, X1 is the reactance within the length of the traction network point (unit: Ω / km), and L is the length of the contact network (unit: km).

[0072] Therefore, the protection setting value of the traction network in the embodiment of the present application is determined by combining the harmonic suppression parameters obtained in step 103 and the traction network distance protection resistor setting value and the traction network distance protection reactance setting value obtained in step 104:

[0073]

[0074] Among them, R' set is the resistance setting value adjusted according to the harmonic content, X' set It is the reactance setting value adjusted according to the harmonic content. After adjustment, the protection setting value of the traction network is determined.

[0075] When K h When >0, the distance protection impedance action boundary is adjusted accordingly to reduce the impact of harmonics.

[0076] like Figure 3 As shown in the figure, due to the inrush current generated by the autotransformer in the sub-area, the autotransformers in other AT stations also generate inrush current, and the second and third harmonics in the excitation current are rich. Figure 3As shown, by monitoring and analyzing the second and third harmonics in the excitation inrush current, the protection setting values ​​are adjusted in time according to the second and third harmonic contents, and then the power supply parameters of the traction network are adjusted according to the protection setting values, harmonic blocking is achieved, and false operation of the traction network protection is avoided. The power quality is monitored in real time, and the setting values ​​of the protection devices are adjusted in time to improve the reliability and stability of the traction network and reduce the operation and maintenance costs and risks.

[0077] like Figure 2 As shown, the embodiment of the present application also provides a device for measuring and analyzing power quality for traction network protection setting, specifically, including a data acquisition module, a communication module and a data processing module.

[0078] The data acquisition module is used to collect the electrical quantity information of the traction network and convert the electrical quantity information into a switch quantity signal to obtain an electrical quantity data sequence.

[0079] Specifically, the data acquisition module includes:

[0080] The electrical quantity acquisition component is used to perform sampling at equal time intervals on the traction network based on multiple sampling points to obtain key signal features.

[0081] It should be noted that the electrical quantity collection components include but are not limited to analog sensors and / or transmitters used to collect information such as voltage, current, excitation voltage, excitation current, active power, reactive power, etc. of the traction network, as well as other intelligent sensors with high precision and fast response speed.

[0082] The data preprocessing unit is used to amplify and filter the key features of the signal to obtain electrical quantity information.

[0083] The analog-to-digital conversion unit is used to perform analog-to-digital conversion on electrical quantity information to obtain a switch quantity signal, and continuously sample the switch quantity signal at equal time intervals to obtain an electrical quantity data sequence.

[0084] The communication module is used to realize data transmission between the data acquisition module and the data processing module.

[0085] The data processing module is used to receive and process the electrical quantity data sequence, determine the harmonic suppression parameters based on the electrical quantity data sequence, and generate a spectrum analysis diagram for display.

[0086] Specifically, the data processing module includes:

[0087] The data receiving unit is used to receive the electrical quantity data sequence uploaded by the data acquisition module.

[0088] The data analysis unit is used to perform data analysis on the electrical quantity data sequence to obtain the harmonic content of each order of the traction network and determine the harmonic suppression parameters based on the content of each order of the harmonic.

[0089] The data storage unit is used to store the electrical quantity information, electrical quantity data sequence, harmonic suppression parameters and protection setting values ​​of the traction network.

[0090] Exemplarily, the data processing module further includes a visualization unit for generating a spectrum analysis diagram based on the electrical quantity data sequence, and displaying the spectrum analysis diagram to a user in a visual manner.

[0091] This application sets the power supply parameters of the traction network and obtains the electrical quantity information of the traction network in real time through multiple sampling points, thus meeting the real-time demand in the process of measuring the power quality of the traction network. At the same time, by converting the electrical quantity information into analog-to-digital data sequence, a faster, more stable and more efficient analog-to-digital conversion process is achieved.

[0092] The present application determines harmonic suppression parameters by using a simplified fast Fourier transform calculation method for an electrical data sequence, obtains protection setting values ​​for a traction network based on the harmonic suppression parameters, and implements a faster and more convenient calculation process for an electrical data sequence.

[0093] This application effectively solves the problems in the prior art of the immature development of monitoring and analysis technology for railway traction networks and the high rate of traction network accidents caused by excessive harmonic content, thereby achieving efficient and stable technical effects for the power quality measurement and analysis process of the traction network.

[0094] Although the present application provides method operation steps as described in the embodiments or flowcharts, more or fewer operation steps may be included based on conventional or non-creative labor. The order of steps listed in this embodiment is only one way of executing the order of many steps and does not represent the only execution order. When the actual device or client product is executed, it can be executed in sequence or in parallel according to the method shown in this embodiment or the accompanying drawings (for example, in a parallel processor or multi-threaded processing environment).

[0095] Some modules in the apparatus described in the present application can be described in the general context of computer executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc. that perform specific tasks or implement specific abstract data types. The present application can also be practiced in distributed computing environments, in which tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0096] The devices or modules described in the above application embodiments can be implemented by computer chips or entities, or by products with certain functions. For the convenience of description, the above devices are described in various modules according to their functions. When implementing the embodiments of the present application, the functions of each module can be implemented in the same or multiple software and / or hardware. Of course, the module that implements a certain function can also be implemented by combining multiple sub-modules or sub-units.

[0097] The methods, devices or modules described in this application can be implemented in the form of computer-readable program codes. The controller can be implemented in any appropriate manner. For example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program codes (such as software or firmware) that can be executed by the (micro) processor, logic gates, switches, application-specific integrated circuits (English: Application Specific Integrated Circuit; Abbreviation: ASIC), programmable logic controllers and embedded microcontrollers. Examples of controllers include but are not limited to the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20 and Silicone Labs C8051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art also know that in addition to implementing the controller in a purely computer-readable program code, the controller can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps. Therefore, this controller can be considered as a hardware component, and the devices included in it for implementing various functions can also be regarded as structures within the hardware component. Or even, the means for realizing various functions may be regarded as both a software module for realizing the method and a structure within a hardware component.

[0098] In addition, each functional module in each embodiment of the present invention may be integrated into one processing module, or each module may exist independently, or two or more modules may be integrated into one module.

[0099] The above storage media include but are not limited to random access memory (RAM), read-only memory (ROM), cache, hard disk (HDD) or memory card. The memory can be used to store computer program instructions.

[0100] It can be known from the description of the above implementation methods that those skilled in the art can clearly understand that the present application can be implemented by means of software plus necessary hardware. Based on such an understanding, the technical solution of the present application can be essentially or partly contributed to the prior art in the form of a software product, or it can be reflected in the implementation process of data migration. The computer software product can be stored in a storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a mobile terminal, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present application or certain parts of the embodiments.

[0101] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. All or part of this application can be used in many general or special computer system environments or configurations. For example: personal computers, server computers, handheld devices or portable devices, tablet devices, mobile communication terminals, multi-processor systems, microprocessor-based systems, programmable electronic devices, network PCs, minicomputers, mainframe computers, distributed computing environments including any of the above systems or devices, etc.

[0102] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A method for measuring and analyzing power quality for traction network protection setting, characterized in that: include: Obtain the electrical quantity information of the traction network in real time; Performing analog-to-digital conversion on the electrical quantity information to obtain an electrical quantity data sequence; Determining harmonic suppression parameters according to the electrical quantity data sequence; The protection setting value of the traction network is adjusted based on the harmonic suppression parameter.

2. The method according to claim 1, characterized in that The electrical quantity information includes current information, voltage information, phase angle, power and harmonic content rate of the traction network; The electrical quantity data sequence includes current data and voltage data.

3. The method according to claim 1, characterized in that The real-time acquisition of electrical quantity information of the traction network includes: Based on multiple sampling points, continuous signals on the traction network are sampled at equal time intervals to obtain key features of the signals; The key features of the signal are amplified and filtered to obtain the electrical quantity information.

4. The method according to claim 1, characterized in that: The step of performing analog-to-digital conversion on the electrical quantity information to obtain an electrical quantity data sequence includes: Performing analog-to-digital conversion on the electrical quantity information to obtain a switch quantity signal; The switch quantity signal is continuously sampled at equal time intervals to obtain the electrical quantity data sequence.

5. The method according to claim 4, characterized in that The determining of harmonic suppression parameters according to the electrical quantity data sequence comprises: Performing data analysis on the electrical quantity data sequence based on fast Fourier transform to obtain the content of each harmonic; Determining harmonic suppression parameters based on the contents of each harmonic; Wherein, the fast Fourier transform is as follows: in, In the formula, F(k) represents the fast Fourier transform function, N represents the total number of elements in the electrical quantity data sequence, n represents the logical address of the element in the electrical quantity data sequence, y is the element in the electrical quantity data sequence, 2y represents the even sequence point, that is, the element with an even logical address in the electrical quantity data sequence, 2y+1 represents the odd sequence point, that is, the element with an odd logical address in the electrical quantity data sequence, f(n) represents the periodic discrete time function signal, f1(y) is the periodic discrete time function signal of the even sequence point, f2(y) is the periodic discrete time function signal of the odd sequence point, F1(k) represents the fast Fourier transform function of the even sequence point in the electrical quantity data sequence, F2(k) represents the fast Fourier transform function of the odd sequence point in the electrical quantity data sequence, e is a natural base, j represents a complex number, k represents the logical address of the element in the electrical quantity data sequence in the fast Fourier transform function, k=0,1,...,N-1.

6. The method according to claim 1, characterized in that After obtaining the electrical quantity data sequence, the method further includes: A spectrum analysis diagram of the traction network is constructed based on the electrical quantity data sequence to display the harmonic distribution of the traction network.

7. A device for performing a method for measuring and analyzing power quality for traction network protection setting, characterized in that: include: A data acquisition module is used to collect electrical quantity information of the traction network and convert the electrical quantity information into a switch quantity signal to obtain an electrical quantity data sequence; Communication module, used to realize data transmission between various modules; The data processing module is used to receive and process the electrical quantity data sequence, determine harmonic suppression parameters based on the electrical quantity data sequence, and generate a spectrum analysis diagram for display.

8. The device according to claim 7, characterized in that The data acquisition module comprises: An electrical quantity acquisition component is used to perform sampling at equal time intervals on the traction network based on multiple sampling points to obtain key signal features; A data preprocessing unit, used for performing signal amplification and filtering processing on the key features of the signal to obtain the electrical quantity information; The analog-to-digital conversion unit is used to perform analog-to-digital conversion on the electrical quantity information to obtain a switch quantity signal, and continuously sample the switch quantity signal at equal time intervals to obtain the electrical quantity data sequence.

9. The device according to claim 7, characterized in that The data processing module comprises: A data receiving unit, used for receiving the electrical quantity data sequence uploaded by the data acquisition module; A data analysis unit, configured to perform data analysis on the electrical quantity data sequence to obtain the harmonic content of each order of the traction network, and determine harmonic suppression parameters based on the harmonic content of each order of the harmonic; A data storage unit is used to store the electrical quantity information of the traction network, the electrical quantity data sequence, the harmonic suppression parameters and the protection setting value.

10. The device according to claim 9, characterized in that The data processing module further includes a visualization unit for generating a spectrum analysis diagram based on the electrical quantity data sequence, and displaying the spectrum analysis diagram to a user in a visualized manner.

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