Power quality disturbance identification method and device for ship power system, medium and electronic equipment

Abstract

The application provides a power quality disturbance identification method and device of a ship power system, a computer readable medium and an electronic device. The method comprises: acquiring a bus instantaneous voltage sequence of the power system, the bus instantaneous voltage sequence comprising a plurality of bus voltage instantaneous values; determining an upper envelope sequence and a lower envelope sequence of the bus instantaneous voltage sequence, and performing normalization processing on the upper envelope sequence and the lower envelope sequence respectively to obtain a normalized upper envelope sequence and a normalized lower envelope sequence; determining a first similarity between the normalized upper envelope sequence and a predetermined Gaussian curve sequence and a second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence respectively; and determining a power quality disturbance category in the power system according to a comparison result of the first similarity and the second similarity. The application can accurately realize power quality disturbance identification on a ship power system and has a lower cost.

Description

Technical Field

[0001] This application relates to the field of power system technology, and more specifically, to a method, apparatus, computer-readable medium, and electronic device for identifying power quality disturbances in a ship's power system. Background Technology

[0002] Currently, the power of ship electrical systems is limited, the grid inertia is small, and the shock resistance is relatively weak. When the power quality of the ship's electrical system is disturbed, voltage fluctuations or distortions can cause equipment such as motors to malfunction, and in severe cases, it can lead to equipment damage and shutdown, posing a risk to navigation safety. Summary of the Invention

[0003] The embodiments of this application provide a method, apparatus, computer-readable medium, and electronic device for identifying power quality disturbances in a ship's power system, thereby enabling accurate identification of power quality disturbances in a ship's power system to at least a certain extent, thus providing a reliable basis for ship fault diagnosis, and at a lower cost.

[0004] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0005] According to one aspect of the embodiments of this application, a method for identifying power quality disturbances in a ship's power system is provided, comprising: acquiring a bus instantaneous voltage sequence of the power system, the bus instantaneous voltage sequence including multiple bus voltage instantaneous values; determining an upper envelope sequence and a lower envelope sequence of the bus instantaneous voltage sequence, and normalizing the upper envelope sequence and the lower envelope sequence respectively to obtain a normalized upper envelope sequence and a normalized lower envelope sequence; determining a first similarity between the normalized upper envelope sequence and a predetermined Gaussian curve sequence and a second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence respectively; and determining the power quality disturbance category in the power system based on the comparison result of the first similarity and the second similarity.

[0006] According to one aspect of the embodiments of this application, a power quality disturbance identification device for a ship's power system is provided. The device includes: a voltage sequence acquisition unit, configured to acquire a bus instantaneous voltage sequence of the power system, the bus instantaneous voltage sequence including multiple bus voltage instantaneous values; a determination and normalization unit, configured to determine an upper envelope sequence and a lower envelope sequence of the bus instantaneous voltage sequence, and normalize the upper envelope sequence and the lower envelope sequence respectively to obtain a normalized upper envelope sequence and a normalized lower envelope sequence; a similarity determination unit, configured to determine a first similarity between the normalized upper envelope sequence and a predetermined Gaussian curve sequence and a second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence respectively; and a disturbance category determination unit, configured to determine the power quality disturbance category in the power system based on the comparison result of the first similarity and the second similarity.

[0007] Optionally, based on the aforementioned scheme, the device further includes a disturbance determination unit; before determining the upper envelope sequence and lower envelope sequence of the instantaneous bus voltage sequence, the disturbance determination unit is used to: determine whether there is a disturbance in the power quality of the power system based on the instantaneous bus voltage sequence, wherein determining the upper envelope sequence and lower envelope sequence of the instantaneous bus voltage sequence is performed under the condition that there is a disturbance in the power quality of the power system.

[0008] Optionally, based on the aforementioned scheme, the disturbance determination unit is configured to: determine the rate of change sequence between adjacent elements of the instantaneous bus voltage sequence; determine the maximum rate of change between adjacent elements of the instantaneous bus voltage sequence based on the rate of change sequence; and determine whether a disturbance has occurred in the power quality of the power system based on the maximum rate of change.

[0009] Optionally, based on the foregoing scheme, the similarity determination unit is configured to: construct a first distance matrix between the normalized upper envelope sequence and the predetermined Gaussian curve sequence; determine a first minimum cumulative distance based on the first distance matrix, wherein the first minimum cumulative distance is used to measure the degree of difference between the normalized upper envelope sequence and the predetermined Gaussian curve sequence after optimal nonlinear time alignment; determine a first similarity between the normalized upper envelope sequence and the predetermined Gaussian curve sequence based on the first minimum cumulative distance, wherein the first similarity is negatively correlated with the first minimum cumulative distance; construct a second distance matrix between the normalized lower envelope sequence and the predetermined Gaussian curve sequence; determine a second minimum cumulative distance based on the second distance matrix, wherein the second minimum cumulative distance is used to measure the degree of difference between the normalized lower envelope sequence and the predetermined Gaussian curve sequence after optimal nonlinear time alignment; and determine a second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence based on the second minimum cumulative distance, wherein the second similarity is negatively correlated with the second minimum cumulative distance.

[0010] Optionally, based on the aforementioned scheme, the similarity determination unit is configured to: construct a first cumulative distance matrix according to the first distance matrix, wherein each element in the first cumulative distance matrix is ​​used to measure the distance of the path with the smallest total distance among all possible paths from the element at the top left corner to the current element; and determine a first minimum cumulative distance according to the first cumulative distance matrix.

[0011] Optionally, based on the aforementioned scheme, the determination and normalization unit is configured to: perform a Hilbert transform on the instantaneous bus voltage sequence to obtain a discrete voltage sequence; construct a complex signal sequence based on the discrete voltage sequence and the instantaneous bus voltage sequence; construct an upper envelope sequence based on the complex signal sequence; and invert the upper envelope sequence to obtain a lower envelope sequence.

[0012] Optionally, based on the aforementioned scheme, the disturbance category determination unit is configured as follows: if the first similarity is greater than the second similarity, the power quality disturbance category in the power system is determined to be a transient rise; if the difference between the first similarity and the second similarity is less than a predetermined difference threshold, the power quality disturbance category in the power system is determined to be a flicker; if the first similarity is less than the second similarity, the power quality disturbance category in the power system is determined to be an interruption.

[0013] According to one aspect of the embodiments of this application, a computer-readable medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method described in the above embodiments.

[0014] According to one aspect of the embodiments of this application, an electronic device is provided, including: one or more processors; and a storage device for storing one or more programs, which, when executed by the one or more processors, cause the one or more processors to perform the method described in the above embodiments.

[0015] In some embodiments of this application, the technical solutions are as follows: first, a bus instantaneous voltage sequence including multiple bus voltage instantaneous values ​​is obtained; then, the upper envelope sequence and lower envelope sequence of the bus instantaneous voltage sequence are determined; and normalization processing is performed to obtain the normalized upper envelope sequence corresponding to the upper envelope sequence and the normalized lower envelope sequence corresponding to the lower envelope sequence. Then, the first similarity between the normalized upper envelope sequence and the predetermined Gaussian curve sequence and the second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence are determined respectively. Finally, the power quality disturbance category in the power system is determined based on the comparison results of the first similarity and the second similarity. Therefore, the solution in this application only requires obtaining the instantaneous bus voltage sequence of the power system to identify power quality disturbances, significantly reducing costs. By creatively obtaining the normalized upper envelope sequence and the normalized lower envelope sequence, and identifying the power quality disturbance category based on the comparison of their similarity with a predetermined Gaussian curve sequence, the accuracy of power quality disturbance identification is improved. This provides a reliable basis for ship fault diagnosis, enhances the timeliness of troubleshooting for relevant personnel, and improves ship navigation safety. The overall solution has a lower engineering cost and can be applied to isolated power grids such as ship power systems, making it suitable for a wider range of engineering applications.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0018] Figure 1 A flowchart of a power quality disturbance identification method for a ship electrical system according to an embodiment of this application is shown;

[0019] Figure 2 A flowchart illustrating a method for identifying power quality disturbances in a ship's electrical system according to an embodiment of this application is shown. Figure 3A structural block diagram of a power quality disturbance identification system for a ship's electrical system according to an embodiment of this application is shown; Figure 4 An embodiment according to this application is shown. Figure 1 A flowchart of the steps preceding step 130 in the embodiment; Figure 5 A detailed flowchart illustrating an embodiment of this application is provided for determining whether a disturbance in the power quality of the power system occurs based on the instantaneous bus voltage sequence. Figure 6 A detailed flowchart illustrating the determination of the upper and lower envelope sequences of the instantaneous bus voltage sequence according to an embodiment of this application is shown. Figure 7 A block diagram of a power quality disturbance identification device for a ship's electrical system according to an embodiment of this application is shown; Figure 8 A schematic diagram of the structure of a computer system suitable for implementing the electronic device of the present application is shown. Detailed Implementation

[0020] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0021] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0022] In the embodiments of this application, the terms "module" or "unit" refer to a computer program or part of a computer program that has a predetermined function and works with other related parts to achieve a predetermined goal, and can be implemented wholly or partially using software, hardware (such as processing circuitry or memory), or a combination thereof. Similarly, a processor (or multiple processors or memory) can be used to implement one or more modules or units. Furthermore, each module or unit can be part of an overall module or unit that includes the functionality of that module or unit.

[0023] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0024] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0025] Driven by the trends of diversified and modular ship functions, the scale and architecture of ship electrical systems have experienced significant growth and become increasingly complex. Compared to land-based power grids, ship electrical systems are essentially isolated maritime power grids. Furthermore, with the development of ship technology, ships have high load power and frequent start-stop cycles due to changing operating conditions, posing a challenge to their electrical systems. Ship electrical systems have limited generator power, low grid inertia, and relatively weak shock resistance. When power quality disturbances occur in the ship's electrical system, voltage fluctuations or distortions can cause motors and other equipment to malfunction, potentially leading to equipment damage and shutdown. Moreover, the poor self-healing capability of ship electrical systems means that failure to promptly and effectively disconnect faulty lines can further expand the fault area, affecting the entire ship's power supply, drastically increasing navigational safety risks, and significantly increasing the threat to crew safety. Timely identification of power quality disturbances in ship electrical systems provides a reliable basis for ship fault diagnosis, enabling appropriate measures to be taken, improving the reliability of the ship's electrical system, and preventing personal and property losses.

[0026] Most of the power quality disturbance identification methods in related technologies are designed for land power grids. The applicability of these methods to ship power systems needs further verification. However, current ships have long sailing distances and long service lives, are mostly customized designs, and operate offline in isolated areas. Applying these power quality disturbance identification methods to ship power systems would make it difficult to obtain effective offline data, and the engineering cost would be relatively high, resulting in poor engineering application scenarios.

[0027] Based on this, this application first provides a method for identifying power quality disturbances in a ship's power system. This method can be applied to isolated power grids such as ship power systems, and is a power quality disturbance identification method with wide engineering application scenarios and low cost.

[0028] Figure 1 A flowchart of a power quality disturbance identification method for a ship's electrical system according to an embodiment of this application is shown. Figure 1The method shown can be performed by a power quality monitoring system on board the ship, which may include a controller. See also... Figure 1 As shown, the power quality disturbance identification method for the ship's electrical system may include the following steps: Step 110: Obtain the instantaneous bus voltage sequence of the power system, wherein the instantaneous bus voltage sequence includes multiple instantaneous bus voltage values.

[0029] The power system can be a ship's power system.

[0030] The bus instantaneous voltage sequence includes bus instantaneous voltage values ​​that can be normalized bus instantaneous voltage values.

[0031] Specifically, the power system may include a main switchboard, on which a bus voltage sensor may be configured; the original instantaneous value of the bus voltage can be collected in real time by the bus voltage sensor configured on the main switchboard, and a normalized instantaneous value of the bus voltage can be obtained based on the original instantaneous value of the bus voltage.

[0032] The bus voltage sensor can continuously sample for a predetermined duration at a predetermined sampling rate to obtain a sequence of original instantaneous bus voltage values, including multiple original instantaneous bus voltage values.

[0033] The predetermined sampling rate can be 1 kHz or other sampling rates; the predetermined duration can be 0.2 seconds or other durations.

[0034] A total of n sampling points were collected to form the instantaneous voltage sequence of the bus. It can also form sampling time series. , n=1,2,3,…n.

[0035] When the predetermined sampling rate is 1kHz and the predetermined duration is 0.2 seconds, n can be 200, meaning a total of 200 sampling points can be collected for the bus instantaneous voltage sequence. It can include 200 elements.

[0036] Bus instantaneous voltage sequence Specifically, it can be: =[0.0000，0.3090，0.5878，0.8090，0.9511，1.0000，0.9511，0.8090，0.5878，0.3090，0.0000，-0.3090，-0.5878，-0.8090，-0.9511，-1.0000，-0.9511，-0.8090，-0.5878，-0.3090，-0.0000，0.3090，0.5878，0.8090，0.9511，1.0000，0.9511，0.8090，0.5878，0.3090，0.0000，-0.3090，-0.5878，-0.8090，-0.9511，-1.0000，-0.9511，-0.8090，-0.5878，-0.3090，-0.0000，0.3090，0.5878，0.8090，0.9511，1.0000，0.9511，0.8090，0.5878，0.3090，-0.0000，-0.3090，-0.5878，-0.8090，-0.9511，-1.0000，-0.9511，-0.8090，-0.5878，-0.3090，-0.0000，0.3090，0.5878，0.8090，0.9511，1.0000，0.9511，0.8090，0.5878，0.3090，-0.0000，-0.3090，-0.5878，-0.8090，-0.9511，-2.0400，-1.9402，-1.6504，-1.1991，-0.6304，-0.0000，0.6304，1.1991，1.6504，1.9402，2.0400，1.9402，1.6504，1.1991，0.6304，0.0000，-0.6304，-1.1991，-1.6504，-1.9402，-2.0400，-1.9402，-1.6504，-1.1991，-0.6304，0.0000，0.6304，1.1991，1.6504，1.9402，2.0400，1.9402，1.6504，1.1991，0.6304，-0.0000，-0.6304，-1.1991，-1.6504，-1.9402，-2.0400，-1.9402，-1.6504，-1.1991，-0.6304，0.0000，0.6304，1.1991，1.6504，1.9402，2.0400，0.9511，0.8090，0.5878，0.3090，-0.0000，-0.3090，-0.5878，-0.8090, -0.9511, -1.0000, -0.9511, -0.8090, -0.5878, -0.3090, 0.0000, 0.3090, 0.5878, 0.8090, 0.9511, 1.0000, 0.9511, 0.8090, 0.5878, 0.3090, -0. 0000, -0.3090, -0.5878, -0.8090, -0.9511, -1.0000, -0.9511, -0.8090, -0.5878, -0.3090, -0.0000, 0.3090, 0.5878, 0.8090, 0.9511, 1.0000, 0.9511 , 0.8090, 0.5878, 0.3090, -0.0000, -0.3090, -0.5878, -0.8090, -0.9511, -1.0000, -0.9511, -0.8090, -0.5878, -0.3090, 0.0000, 0.3090, 0.5878, 0.8 090, 0.9511, 1.0000, 0.9511, 0.8090, 0.5878, 0.3090, -0.0000, -0.3090, -0.5878, -0.8090, -0.9511, -1.0000, -0.9511, -0.8090, -0.5878, -0.3090].

[0037] Figure 2 A schematic flowchart illustrating a method for identifying power quality disturbances in a ship's electrical system according to an embodiment of this application is shown. Please refer to... Figure 2 As shown, the process may include the following: Step 201: Real-time sampling of the instantaneous value of the main bus voltage, and based on the normalized instantaneous value of the bus voltage, forming a bus instantaneous voltage sequence and a sampling time sequence.

[0038] Figure 3 A structural block diagram of a power quality disturbance identification system for a ship's electrical system according to an embodiment of this application is shown. Please refer to... Figure 3 As shown, the power quality disturbance identification system of the ship's power system may include a real-time sampling module 301, which can sample the instantaneous value of the main bus voltage in real time.

[0039] Figure 4 An embodiment according to this application is shown. Figure 1 A flowchart of the steps preceding step 130 in this embodiment. Please refer to [link / reference]. Figure 4 As shown, before determining the upper and lower envelope sequences of the instantaneous bus voltage sequence, the power quality disturbance identification method for the ship's power system may further include the following steps: Step 120: Determine whether there is a disturbance in the power quality of the power system based on the instantaneous bus voltage sequence.

[0040] Step 130 is executed only if there is a disturbance in the power quality of the power system; if there is no disturbance in the power quality of the power system, step 130 and subsequent steps can be skipped, meaning the entire process can end or return to step 110. The advantage of doing this is that it can effectively save computing resources.

[0041] In other words, the determination of the upper and lower envelope sequences of the instantaneous bus voltage sequence can be carried out under the condition that the power quality of the power system is disturbed.

[0042] Figure 5 A detailed flowchart illustrating an embodiment of this application is provided for determining whether a disturbance in the power quality of the power system has occurred based on the instantaneous bus voltage sequence. Please refer to [link to relevant documentation]. Figure 5 As shown, determining whether there is a disturbance in the power quality of the power system based on the instantaneous bus voltage sequence can specifically include the following steps: Step 510: Determine the rate of change sequence between adjacent elements of the instantaneous bus voltage sequence.

[0043] The rate of change sequence can be obtained as follows: For each element in the instantaneous bus voltage sequence except the first element, determine the difference between the element and the element preceding and adjacent to it; obtain the acquisition time difference between the element and the element preceding and adjacent to it; determine the rate of change corresponding to the element based on the acquisition time difference; determine the rate of change corresponding to each element in the instantaneous bus voltage sequence except the first element in turn to obtain the rate of change sequence.

[0044] Specifically, the rate of change sequence can be obtained using the following formula. : , in, This is the instantaneous voltage sequence of the busbar. Bus instantaneous voltage sequence The sampling time interval.

[0045] Bus instantaneous voltage sequence Taking the aforementioned 200 elements as an example, based on the bus instantaneous voltage sequence The obtained rate of change sequence It can be: =[0.0015，0.0015，0.0013，0.0009，0.0005，0.0000，-0.0005，-0.0009，-0.0013，-0.0015，-0.0015，-0.0015，-0.0013，-0.0009，-0.0005，-0.0000，0.0005，0.0009，0.0012，0.0015，0.0015，0.0015，0.0012，0.0009，0.0005，-0.0000，-0.0005，-0.0009，-0.0012，-0.0015，-0.0015，-0.0015，-0.0013，-0.0009，-0.0005，0.0000，0.0005，0.0009，0.0012，0.0015，0.0015，0.0015，0.0012，0.0009，0.0005，0.0000，-0.0005，-0.0009，-0.0013，-0.0015，-0.0015，-0.0015，-0.0012，-0.0009，-0.0005，-0.0000，0.0005，0.0009，0.0013，0.0015，0.0015，0.0015，0.0012，0.0009，0.0005，-0.0000，-0.0005，-0.0009，-0.0013，-0.0015，-0.0015，-0.0015，-0.0012，-0.0009，-0.0031，-0.0025，0.0010，0.0019，0.0026，0.0030，0.0032，0.0030，0.0025，0.0019，0.0010，-0.0000，-0.0010，-0.0019，-0.0025，-0.0030，-0.0032，-0.0030，-0.0025，-0.0019，-0.0010，0.0000，0.0010，0.0019，0.0026，0.0030，0.0032，0.0030，0.0026，0.0019，0.0010，-0.0000，-0.0010，-0.0019，-0.0026，-0.0030，-0.0032，-0.0030，-0.0025，-0.0019，-0.0010，0.0000，0.0010，0.0019，0.0026，0.0030，0.0032，0.0030，0.0026，0.0019，0.0010，-0.0025，-0.0031，-0.0009，-0.0012，-0.0015，-0.0015，-0.0015，-0.0012, -0.0009, -0.0005, 0.0000, 0.0005, 0.0009, 0.0013, 0.0015, 0.0015, 0.0015, 0.0012, 0.0009, 0.0005, -0.0000, -0.0005, -0.0009, -0.0013, -0. 0015, -0.0015, -0.0015, -0.0012, -0.0009, -0.0005, 0.0000, 0.0005, 0.0009, 0.0013, 0.0015, 0.0015, 0.0015, 0.0013, 0.0009, 0.0005, -0.0000, -0.0 005, -0.0009, -0.0013, -0.0015, -0.0015, -0.0015, -0.0013, -0.0009, -0.0005, 0.0000, 0.0005, 0.0009, 0.0013, 0.0015, 0.0015, 0.0015, 0.0012, 0. 0009, 0.0005, 0.0000, -0.0005, -0.0009, -0.0012, -0.0015, -0.0015, -0.0015, -0.0012, -0.0009, -0.0005, 0.0000, 0.0005, 0.0009, 0.0012, 0.0015].

[0046] Step 520: Determine the maximum rate of change between adjacent elements of the instantaneous bus voltage sequence based on the rate of change sequence.

[0047] The instantaneous voltage sequence of the bus can be determined by the following formula. The maximum rate of change between adjacent elements: , in, It is a sequence of rates of change. This represents the maximum rate of change.

[0048] Based on the rate of change sequence provided in the above example From the data, we can obtain: 0.0032.

[0049] Step 530: Determine whether there is a disturbance in the power quality of the power system based on the maximum rate of change.

[0050] A disturbance in power quality in a power system can be determined by comparing the maximum rate of change with a predetermined maximum rate of change threshold. If the maximum rate of change exceeds the predetermined maximum rate of change threshold, a disturbance in power quality can be identified in the power system.

[0051] The predetermined maximum rate of change threshold can be a set threshold. It can be 0.2 or other values.

[0052] The predetermined maximum rate of change threshold can be obtained based on historical monitoring data.

[0053] Please continue reading Figure 2 As shown, in step 202, the maximum rate of change of the instantaneous voltage sequence of the bus is calculated and compared with the setting threshold to determine whether there is a disturbance in the power quality of the ship's power system.

[0054] Please continue reading Figure 3 As shown, the power quality disturbance identification system of a ship's power system may include a power quality disturbance discrimination module 302, which compares the maximum rate of change of the instantaneous voltage sequence of the bus with a set threshold to determine whether there is a disturbance in the power quality of the ship's power system.

[0055] Please continue reading Figure 1 Step 130: Determine the upper envelope sequence and lower envelope sequence of the instantaneous voltage sequence of the bus, and normalize the upper envelope sequence and the lower envelope sequence respectively to obtain the normalized upper envelope sequence and the normalized lower envelope sequence.

[0056] The upper and lower envelope sequences of the instantaneous bus voltage sequence can be obtained separately using the Hilbert transform.

[0057] Please continue reading Figure 2 As shown, in step 203, the upper and lower envelope sequences are obtained by performing Hilbert transform on the instantaneous voltage sequence of the bus, and then normalized to obtain the normalized upper and lower envelope sequences.

[0058] Please continue reading Figure 3 As shown, the power quality disturbance identification system of the ship's power system may include a signal processing module 303, which can perform Hilbert transform on the instantaneous voltage sequence of the bus to obtain the upper and lower envelope sequences and perform normalization processing.

[0059] Figure 6 A detailed flowchart illustrating the determination of the upper and lower envelope sequences of the instantaneous bus voltage sequence according to an embodiment of this application is shown. Please refer to... Figure 6As shown, determining the upper and lower envelope sequences of the instantaneous bus voltage sequence can specifically include the following steps: Step 610: Perform Hilbert transform on the instantaneous voltage sequence of the bus to obtain a discrete voltage sequence.

[0060] Specifically, the instantaneous voltage sequence of the bus can be expressed by the following formula. Perform the Hilbert transform: , in, For the instantaneous voltage sequence of the bus Discrete voltage sequences obtained by performing Hilbert transform.

[0061] Based on the bus instantaneous voltage sequence data provided in the above example, the discrete voltage sequence is obtained. It can be: =[0.0000，0.3090，0.5878，0.8090，0.9511，1.0000，0.9511，0.8090，0.5878，0.3090，-0.0000，-0.3090，-0.5878，-0.8090，-0.9511，-1.0000，-0.9511，-0.8090，-0.5878，-0.3090，-0.0000，0.3090，0.5878，0.8090，0.9511，1.0000，0.9511，0.8090，0.5878，0.3090，0.0000，-0.3090，-0.5878，-0.8090，-0.9511，-1.0000，-0.9511，-0.8090，-0.5878，-0.3090，-0.0000，0.3090，0.5878，0.8090，0.9511，1.0000，0.9511，0.8090，0.5878，0.3090，-0.0000，-0.3090，-0.5878，-0.8090，-0.9511，-1.0000，-0.9511，-0.8090，-0.5878，-0.3090，-0.0000，0.3090，0.5878，0.8090，0.9511，1.0000，0.9511，0.8090，0.5878，0.3090，-0.0000，-0.3090，-0.5878，-0.8090，-0.9511，-2.0400，-1.9402，-1.6504，-1.1991，-0.6304，-0.0000，0.6304，1.1991，1.6504，1.9402，2.0400，1.9402，1.6504，1.1991，0.6304，0.0000，-0.6304，-1.1991，-1.6504，-1.9402，-2.0400，-1.9402，-1.6504，-1.1991，-0.6304，0.0000，0.6304，1.1991，1.6504，1.9402，2.0400，1.9402，1.6504，1.1991，0.6304，-0.0000，-0.6304，-1.1991，-1.6504，-1.9402，-2.0400，-1.9402，-1.6504，-1.1991，-0.6304，0.0000，0.6304，1.1991，1.6504，1.9402，2.0400，0.9511，0.8090，0.5878，0.3090，-0.0000，-0.3090，-0.5878，-0.8090, -0.9511, -1.0000, -0.9511, -0.8090, -0.5878, -0.3090, 0.0000, 0.3090, 0.5878, 0.8090, 0.9511, 1.0000, 0.9511, 0.8090, 0.5878, 0.3090, -0. 0000, -0.3090, -0.5878, -0.8090, -0.9511, -1.0000, -0.9511, -0.8090, -0.5878, -0.3090, -0.0000, 0.3090, 0.5878, 0.8090, 0.9511, 1.0000, 0.9511 , 0.8090, 0.5878, 0.3090, -0.0000, -0.3090, -0.5878, -0.8090, -0.9511, -1.0000, -0.9511, -0.8090, -0.5878, -0.3090, 0.0000, 0.3090, 0.5878, 0.8 090, 0.9511, 1.0000, 0.9511, 0.8090, 0.5878, 0.3090, -0.0000, -0.3090, -0.5878, -0.8090, -0.9511, -1.0000, -0.9511, -0.8090, -0.5878, -0.3090].

[0062] Step 620: Construct a complex signal sequence based on the discrete voltage sequence and the instantaneous bus voltage sequence.

[0063] A complex signal sequence is a constructed analytic signal. A complex signal sequence can be obtained as follows: , in, It is a discrete voltage sequence. It is a complex signal sequence. This is the instantaneous voltage sequence of the bus.

[0064] Step 630: Construct an upper envelope sequence based on the complex signal sequence.

[0065] In one embodiment of this application, constructing an upper envelope sequence based on the complex signal sequence includes: obtaining the modulus of the complex signal sequence to obtain the upper envelope sequence.

[0066] Specifically, the upper envelope sequence can be obtained through the following calculation method: , in, It is a complex signal sequence. Used to calculate the modulus. This is the upper envelope sequence.

[0067] The upper envelope sequence obtained from the above data It can be: =[0.7901，0.9603，0.9465，0.9882，0.9889，1.0001，1.0083，1.0050，1.0161，1.0062，1.0162，1.0050，1.0113，1.0027，1.0039，1.0000，0.9965，0.9978，0.9914，0.9966，0.9898，0.9967，0.9920，0.9980，0.9970，1.0000，1.0030，1.0020，1.0079，1.0033，1.0099，1.0034，1.0082，1.0022，1.0032，1.0000，0.9967，0.9976，0.9909，0.9960，0.9882，0.9957，0.9899，0.9972，0.9959，1.0000，1.0045，1.0034，1.0127，1.0060，1.0172，1.0067，1.0154，1.0047，1.0068，1.0000，0.9928，0.9937，0.9775，0.9878，0.9670，0.9851，0.9680，0.9885，0.9858，1.0003，1.0218，1.0213，1.0731，1.0501，1.1341，1.0823，1.2031，1.1097，1.4143，2.1299，2.0180，1.9439，2.0243，1.9578，2.0392，1.9896，2.0457，2.0188，2.0433，2.0402，2.0362，2.0524，2.0291，2.0564，2.0261，2.0540，2.0286，2.0476，2.0356，2.0400，2.0445，2.0335，2.0516，2.0297，2.0543，2.0297，2.0516，2.0335，2.0445，2.0400，2.0356，2.0476，2.0286，2.0540，2.0261，2.0564，2.0291，2.0524，2.0362，2.0402，2.0433，2.0188，2.0457，1.9896，2.0392，1.9578，2.0243，1.9439，2.0180，2.1299，1.4143，1.1097，1.2031，1.0823，1.1341，1.0501，1.0731，1.0213，1.0218，1.0003，0.9858，0.9885，0.9680，0.9851，0.9670，0.9878，0.9775, 0.9937, 0.9928, 1.0000, 1.0068, 1.0047, 1.0154, 1.0067, 1.0172, 1.0060, 1.0127, 1.0034, 1.0045, 1.0000, 0.9959, 0.9972, 0.9899, ​​0.9957, 0.9882, 0.9960, 0.9909, 0.9976, 0.9967, 1.0000, 1.0032, 1.0022, 1.0082, 1.0034, 1.0099, 1 .0033, 1.0079, 1.0020, 1.0030, 1.0000, 0.9970, 0.9980, 0.9920, 0.9967, 0.9898, 0.9966, 0.9914, 0.9978, 0.9965, 1.0000, 1.0039, 1.0027, 1.0113, 1.0050, 1.0162, 1.0062, 1.0161, 1.0050, 1.0083, 1.0001, 0.9889, 0.9882, 0.9465, 0.9603].

[0068] Step 640: Invert the upper envelope sequence to obtain the lower envelope sequence.

[0069] The lower envelope sequence can be obtained through the following calculation method: , in, The upper envelope sequence, This is the lower envelope sequence.

[0070] The lower envelope sequence obtained from the above data It can be: =[-0.7901，-0.9603，-0.9465，-0.9882，-0.9889，-1.0001，-1.0083，-1.0050，-1.0161，-1.0062，-1.0162，-1.0050，-1.0113，-1.0027，-1.0039，-1.0000，-0.9965，-0.9978，-0.9914，-0.9966，-0.9898，-0.9967，-0.9920，-0.9980，-0.9970，-1.0000，-1.0030，-1.0020，-1.0079，-1.0033，-1.0099，-1.0034，-1.0082，-1.0022，-1.0032，-1.0000，-0.9967，-0.9976，-0.9909，-0.9960，-0.9882，-0.9957，-0.9899，-0.9972，-0.9959，-1.0000，-1.0045，-1.0034，-1.0127，-1.0060，-1.0172，-1.0067，-1.0154，-1.0047，-1.0068，-1.0000，-0.9928，-0.9937，-0.9775，-0.9878，-0.9670，-0.9851，-0.9680，-0.9885，-0.9858，-1.0003，-1.0218，-1.0213，-1.0731，-1.0501，-1.1341，-1.0823，-1.2031，-1.1097，-1.4143，-2.1299，-2.0180，-1.9439，-2.0243，-1.9578，-2.0392，-1.9896，-2.0457，-2.0188，-2.0433，-2.0402，-2.0362，-2.0524，-2.0291，-2.0564，-2.0261，-2.0540，-2.0286，-2.0476，-2.0356，-2.0400，-2.0445，-2.0335，-2.0516，-2.0297，-2.0543，-2.0297，-2.0516，-2.0335，-2.0445，-2.0400，-2.0356，-2.0476，-2.0286，-2.0540，-2.0261，-2.0564，-2.0291，-2.0524，-2.0362，-2.0402，-2.0433，-2.0188，-2.0457，-1.9896，-2.0392，-1.9578，-2.0243，-1.9439，-2.0180, -2.1299, -1.4143, -1.1097, -1.2031, -1.0823, -1.1341, -1.0501, -1.0731, -1.0213, -1.0218, -1.0003, -0.9858, -0.9885, -0.9680, -0.9851, -0.9670, -0.9878, -0.9775, -0 0.9937, -0.9928, -1.0000, -1.0068, -1.0047, -1.0154, -1.0067, -1.0172, -1.0060, -1.0127, -1.0034, -1.0045, -1.0000, -0.9959, -0.9972, -0.9899, ​​-0.9957, -0.9882, -0.9960, -0 0.9909, -0.9976, -0.9967, -1.0000, -1.0032, -1.0022, -1.0082, -1.0034, -1.0099, -1.0033, -1.0079, -1.0020, -1.0030, -1.0000, -0.9970, -0.9980, -0.9920, -0.9967, -0.9898, - 0.9966, -0.9914, -0.9978, -0.9965, -1.0000, -1.0039, -1.0027, -1.0113, -1.0050, -1.0162, -1.0062, -1.0161, -1.0050, -1.0083, -1.0001, -0.9889, -0.9882, -0.9465, -0.9603].

[0071] By analyzing the upper envelope sequence respectively and lower envelope sequence By performing normalization separately, we can obtain the normalized upper envelope sequence. and normalized lower envelope sequence .

[0072] Specifically, the normalized upper envelope sequence can be calculated using the following formula. : , in, The upper envelope sequence, This is the normalized upper envelope sequence.

[0073] That is, the normalized upper envelope sequence can be obtained by subtracting 1 from each element in the upper envelope sequence.

[0074] The normalized upper envelope sequence obtained from the above data It can be: =[-0.2099，-0.0397，-0.0535，-0.0118，-0.0111，0.0001，0.0083，0.0050，0.0161，0.0062，0.0162，0.0050，0.0113，0.0027，0.0039，0.0000，-0.0035，-0.0022，-0.0086，-0.0034，-0.0102，-0.0033，-0.0080，-0.0020，-0.0030，0.0000，0.0030，0.0020，0.0079，0.0033，0.0099，0.0034，0.0082，0.0022，0.0032，0.0000，-0.0033，-0.0024，-0.0091，-0.0040，-0.0118，-0.0043，-0.0101，-0.0028，-0.0041，0.0000，0.0045，0.0034，0.0127，0.0060，0.0172，0.0067，0.0154，0.0047，0.0068，0.0000，-0.0072，-0.0063，-0.0225，-0.0122，-0.0330，-0.0149，-0.0320，-0.0115，-0.0142，0.0003，0.0218，0.0213，0.0731，0.0501，0.1341，0.0823，0.2031，0.1097，0.4143，1.1299，1.0180，0.9439，1.0243，0.9578，1.0392，0.9896，1.0457，1.0188，1.0433，1.0402，1.0362，1.0524，1.0291，1.0564，1.0261，1.0540，1.0286，1.0476，1.0356，1.0400，1.0445，1.0335，1.0516，1.0297，1.0543，1.0297，1.0516，1.0335，1.0445，1.0400，1.0356，1.0476，1.0286，1.0540，1.0261，1.0564，1.0291，1.0524，1.0362，1.0402，1.0433，1.0188，1.0457，0.9896，1.0392，0.9578，1.0243，0.9439，1.0180，1.1299，0.4143，0.1097，0.2031，0.0823，0.1341，0.0501，0.0731，0.0213，0.0218，0.0003，-0.0142，-0.0115, -0.0320, -0.0149, -0.0330, -0.0122, -0.0225, -0.0063, -0.0072, 0.0000, 0.0068, 0.0047, 0.0154, 0.0067, 0.0172, 0.0060, 0.0127, 0.0034, 0.0045, 0.0000, -0.0041, -0.0028, -0.0101, -0.0043, -0.0118, -0.0040, -0.0091, -0.0024, -0.0033, 0.0000, 0.0032, 0.0022, 0.0 082, 0.0034, 0.0099, 0.0033, 0.0079, 0.0020, 0.0030, 0.0000, -0.0030, -0.0020, -0.0080, -0.0033, -0.0102, -0.0034, -0.0086, -0.0022, -0.0035, 0.0000, 0.0039, 0.0027, 0.0113, 0.0050, 0.0162, 0.0062, 0.0161, 0.0050, 0.0083, 0.0001, -0.0111, -0.0118, -0.0535, -0.0397].

[0075] The normalized lower envelope sequence can be calculated using the following formula. : , in, The lower envelope sequence, This is the normalized lower envelope sequence.

[0076] That is, the normalized lower envelope sequence can be obtained by adding 1 to each element in the lower envelope sequence.

[0077] The normalized lower envelope sequence obtained from the above data It can be: =[0.2099，0.0397，0.0535，0.0118，0.0111，-0.0001，-0.0083，-0.0050，-0.0161，-0.0062，-0.0162，-0.0050，-0.0113，-0.0027，-0.0039，-0.0000，0.0035，0.0022，0.0086，0.0034，0.0102，0.0033，0.0080，0.0020，0.0030，-0.0000，-0.0030，-0.0020，-0.0079，-0.0033，-0.0099，-0.0034，-0.0082，-0.0022，-0.0032，-0.0000，0.0033，0.0024，0.0091，0.0040，0.0118，0.0043，0.0101，0.0028，0.0041，-0.0000，-0.0045，-0.0034，-0.0127，-0.0060，-0.0172，-0.0067，-0.0154，-0.0047，-0.0068，-0.0000，0.0072，0.0063，0.0225，0.0122，0.0330，0.0149，0.0320，0.0115，0.0142，-0.0003，-0.0218，-0.0213，-0.0731，-0.0501，-0.1341，-0.0823，-0.2031，-0.1097，-0.4143，-1.1299，-1.0180，-0.9439，-1.0243，-0.9578，-1.0392，-0.9896，-1.0457，-1.0188，-1.0433，-1.0402，-1.0362，-1.0524，-1.0291，-1.0564，-1.0261，-1.0540，-1.0286，-1.0476，-1.0356，-1.0400，-1.0445，-1.0335，-1.0516，-1.0297，-1.0543，-1.0297，-1.0516，-1.0335，-1.0445，-1.0400，-1.0356，-1.0476，-1.0286，-1.0540，-1.0261，-1.0564，-1.0291，-1.0524，-1.0362，-1.0402，-1.0433，-1.0188，-1.0457，-0.9896，-1.0392，-0.9578，-1.0243，-0.9439，-1.0180，-1.1299，-0.4143，-0.1097，-0.2031, -0.0823, -0.1341, -0.0501, -0.0731, -0.0213, -0.0218, -0.0003, 0.0142, 0.0115, 0.0320, 0.0149, 0.0330, 0.0122, 0.0225, 0.0063, 0.0072, -0.0000, -0. 0068, -0.0047, -0.0154, -0.0067, -0.0172, -0.0060, -0.0127, -0.0034, -0.0045, -0.0000, 0.0041, 0.0028, 0.0101, 0.0043, 0.0118, 0.0040, 0.0091, 0.0024, 0.0 033, -0.0000, -0.0032, -0.0022, -0.0082, -0.0034, -0.0099, -0.0033, -0.0079, -0.0020, -0.0030, -0.0000, 0.0030, 0.0020, 0.0080, 0.0033, 0.0102, 0.0034, 0. 0086, 0.0022, 0.0035, -0.0000, -0.0039, -0.0027, -0.0113, -0.0050, -0.0162, -0.0062, -0.0161, -0.0050, -0.0083, -0.0001, 0.0111, 0.0118, 0.0535, 0.0397].

[0078] Step 140: Determine the first similarity between the normalized upper envelope sequence and the predetermined Gaussian curve sequence, and the second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence.

[0079] The similarity between the normalized upper envelope sequence or the normalized lower envelope sequence and the predetermined Gaussian curve sequence can be calculated directly. Alternatively, the distance between the normalized upper envelope sequence or the normalized lower envelope sequence and the predetermined Gaussian curve sequence can be calculated first, and the similarity between the normalized upper envelope sequence or the normalized lower envelope sequence and the predetermined Gaussian curve sequence can be calculated based on this distance. In this case, the distance can be negatively correlated with the similarity.

[0080] The first similarity between the normalized upper envelope sequence and the predetermined Gaussian curve sequence and the second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence can be determined by Dynamic Time Warping (DTW).

[0081] In one embodiment of this application, determining the first similarity between the normalized upper envelope sequence and the predetermined Gaussian curve sequence, and the second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence, respectively, includes: constructing a first distance matrix between the normalized upper envelope sequence and the predetermined Gaussian curve sequence; determining a first minimum cumulative distance based on the first distance matrix, wherein the first minimum cumulative distance is used to measure the degree of difference between the normalized upper envelope sequence and the predetermined Gaussian curve sequence after optimal nonlinear time alignment; and determining the similarity between the normalized upper envelope sequence and the predetermined Gaussian curve sequence based on the first minimum cumulative distance. A first similarity is obtained between the predetermined Gaussian curve sequence and the predetermined Gaussian curve sequence, wherein the first similarity is negatively correlated with the first minimum cumulative distance; a second distance matrix is ​​constructed between the normalized lower envelope sequence and the predetermined Gaussian curve sequence; a second minimum cumulative distance is determined based on the second distance matrix, wherein the second minimum cumulative distance is used to measure the degree of difference between the normalized lower envelope sequence and the predetermined Gaussian curve sequence after optimal nonlinear time alignment; a second similarity is determined between the normalized lower envelope sequence and the predetermined Gaussian curve sequence based on the second minimum cumulative distance, wherein the second similarity is negatively correlated with the second minimum cumulative distance.

[0082] Pre-defined Gaussian curve sequence It can be calculated using the following formula: , in, Let be the height of the peak of the Gaussian curve, b be the coordinates of the peak center, and c be the standard deviation. This is a sampling time series.

[0083] The value of b can be 1, the value of c can be 0.1, and the value of c can be 0.02.

[0084] Therefore, a predetermined Gaussian curve sequence is required. It can be: =[0.0000，0.0000，0.0000，0.0000，0.0000，0.0000，0.0000，0.0000，0.0000，0.0000，0.0000，0.0001，0.0001，0.0001，0.0001，0.0001，0.0001，0.0002，0.0002，0.0003，0.0003，0.0004，0.0005，0.0006，0.0007，0.0009，0.0011，0.0013，0.0015，0.0018，0.0022，0.0026，0.0031，0.0037，0.0043，0.0051，0.0060，0.0070，0.0082，0.0095，0.0111，0.0129，0.0149，0.0172，0.0198，0.0228，0.0261，0.0299，0.0340，0.0387，0.0439，0.0497，0.0561，0.0632，0.0710，0.0796，0.0889，0.0991，0.1103，0.1223，0.1353，0.1494，0.1645，0.1806，0.1979，0.2163，0.2357，0.2563，0.2780，0.3008，0.3247，0.3495，0.3753，0.4020，0.4296，0.4578，0.4868，0.5162，0.5461，0.5762，0.6065，0.6368，0.6670，0.6968，0.7261，0.7548，0.7827，0.8096，0.8353，0.8596，0.8825，0.9037，0.9231，0.9406，0.9560，0.9692，0.9802，0.9888，0.9950，0.9988，1.0000，0.9988，0.9950，0.9888，0.9802，0.9692，0.9560，0.9406，0.9231，0.9037，0.8825，0.8596，0.8353，0.8096，0.7827，0.7548，0.7261，0.6968，0.6670，0.6368，0.6065，0.5762，0.5461，0.5162，0.4868，0.4578，0.4296，0.4020，0.3753，0.3495，0.3247，0.3008，0.2780，0.2563，0.2357，0.2163，0.1979，0.1806，0.1645，0.1494，0.1353，0.1223，0.1103, 0.0991, 0.0889, 0.0796, 0.0710, 0.0632, 0.0561, 0.0497, 0.0439, 0.0387, 0.0340, 0.0299, 0.0261, 0.0228, 0.0198, 0.0172, 0.0149, 0.0129, 0.0111, 0.0095, 0.0082, 0.0070, 0.0060, 0.0051, 0.0043, 0.0037, 0.0031, 0.0026, 0.0022, 0 .0018, 0.0015, 0.0013, 0.0011, 0.0009, 0.0007, 0.0006, 0.0005, 0.0004, 0.0003, 0.0003, 0.0002, 0.0002, 0.0001, 0.0001, 0.0001, 0.0001, 0.0001, 0.0001, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000, 0.0000.

[0085] The first distance matrix can be determined based on the Mahalanobis distance between the elements of the normalized upper envelope sequence and the predetermined Gaussian curve sequence. The elements of the first distance matrix can be the squares of the Mahalanobis distances between the elements of the normalized upper envelope sequence and the predetermined Gaussian curve sequence.

[0086] Specifically, the first distance matrix can be obtained in the following way. : , in, Let i = 1, 2, 3, ..., n, j = 1, 2, 3, ..., n. Let be the Mahalanobis distance between the i-th element of the normalized upper envelope sequence and the j-th element of the predetermined Gaussian curve sequence, that is... ; It is the square of the Mahalanobis distance between the i-th element of the normalized upper envelope sequence and the j-th element of the predetermined Gaussian curve sequence.

[0087] Similarly, the second distance matrix can be determined based on the Mahalanobis distance between the elements of the normalized lower envelope sequence and the predetermined Gaussian curve sequence. The elements of the second distance matrix can be the squares of the Mahalanobis distances between the elements of the normalized lower envelope sequence and the predetermined Gaussian curve sequence.

[0088] Specifically, the second distance matrix can be obtained as follows: : , in, Let i = 1, 2, 3, ..., n, j = 1, 2, 3, ..., n. Let be the Mahalanobis distance between the i-th element of the normalized lower envelope sequence and the j-th element of the predetermined Gaussian curve sequence, that is... ; It is the square of the Mahalanobis distance between the i-th element of the normalized lower envelope sequence and the j-th element of the predetermined Gaussian curve sequence.

[0089] In one embodiment of this application, determining the first minimum cumulative distance based on the first distance matrix includes: constructing a first cumulative distance matrix based on the first distance matrix, wherein each element in the first cumulative distance matrix is ​​used to measure the distance of the path with the smallest total distance among all possible paths from the top-left element to the current element; and determining the first minimum cumulative distance based on the first cumulative distance matrix.

[0090] The minimum cumulative distance, also known as the minimum cumulative distance of dynamic DTW, is the distance between two sequences corresponding to the optimal alignment path. It is also a quantitative indicator that measures the overall morphological difference between two sequences under optimal elastic alignment, and measures the "total cost after elastic alignment".

[0091] The minimum cumulative distance is the dynamic normalization distance. The first minimum cumulative distance is the dynamic normalization distance corresponding to the normalized upper envelope sequence. The second minimum cumulative distance is the dynamic normalization distance corresponding to the normalized lower envelope sequence. .

[0092] The value of element D[i,j] in the cumulative distance matrix D represents the distance of the path with the smallest total distance among all possible paths from the starting point (0,0) to (i,j).

[0093] The recursive formula for calculating D[i,j] can be: D[i,j]=cost(i,j)+min(D[i-1,j],D[i,j-1,D[i-1,j-1]), Where cost(i,j) is the value of the element at position (i,j) in the distance matrix.

[0094] After obtaining the cumulative distance matrix, the value in the lower right corner of the matrix can be used as the minimum cumulative distance.

[0095] Of course, the optimal regularized path, i.e. the path with the minimum cumulative distance, can also be determined based on the first distance matrix, and the minimum cumulative distance can be obtained based on the optimal regularized path.

[0096] The first minimum cumulative distance and the second minimum cumulative distance can be obtained in the same way; the first similarity and the second similarity can be obtained in the same way.

[0097] The first minimum cumulative distance obtained from the above data It can be: =10.7229.

[0098] The second minimum cumulative distance obtained from the above data It can be: =99.9281.

[0099] The first similarity can be obtained in the following way: , in, The first similarity score, This is the first minimum cumulative distance.

[0100] The first similarity score obtained from the above data can be: =0.0853.

[0101] The second similarity can be obtained in the following way: , in, For the second similarity, This is the second minimum cumulative distance.

[0102] The second similarity obtained from the above data can be: =0.0099.

[0103] Step 150: Determine the power quality disturbance category in the power system based on the comparison result of the first similarity and the second similarity.

[0104] First, the second upward correction similarity and the second downward correction similarity can be determined based on the second similarity. If the first similarity is above the second upward correction similarity, the power quality disturbance category in the power system is determined to be a transient rise. If the first similarity is below the second downward correction similarity, the power quality disturbance category in the power system is determined to be an interruption. If the first similarity is between the second upward correction similarity and the second downward correction similarity, the power quality disturbance category in the power system can be determined to be flicker, and the second downward correction similarity is less than the second upward correction similarity.

[0105] A second upwardly corrected similarity can be obtained by increasing the second similarity by a first predetermined proportion or a first predetermined value; a second downwardly corrected similarity can be obtained by decreasing the second similarity by a second predetermined proportion or a second predetermined value. The first predetermined proportion and the second predetermined proportion can be the same or different; the first predetermined value and the second predetermined value can be the same or different.

[0106] In one embodiment of this application, determining the power quality disturbance category in the power system based on the comparison result of the first similarity and the second similarity includes: if the first similarity is greater than the second similarity, then determining the power quality disturbance category in the power system as a transient rise; if the difference between the first similarity and the second similarity is less than a predetermined difference threshold, then determining the power quality disturbance category in the power system as a flicker; if the first similarity is less than the second similarity, then determining the power quality disturbance category in the power system as an interruption.

[0107] When the first similarity is greater than the second similarity, and the difference between the first and second similarities (or the absolute value of the difference between the first and second similarities) reaches a predetermined difference threshold, the power quality disturbance in the power system can be determined to be a transient rise; when the first similarity is less than the second similarity, and the difference between the first and second similarities (or the absolute value of the difference between the second and first similarities) reaches a predetermined difference threshold, the power quality disturbance in the power system can be determined to be an interruption.

[0108] When the absolute value of the difference between the first similarity and the second similarity is less than a predetermined difference threshold, the power quality disturbance in the power system can be identified as flicker. The predetermined difference threshold can be a very small value, that is, when the first similarity is approximately equal to the second similarity, the power quality disturbance in the power system can be identified as flicker.

[0109] Specifically, the types of power quality disturbances in a power system can be determined in the following ways: , Among them, if Approximately equal to If so, the power quality disturbance in the power system can be classified as flicker.

[0110] Based on the above data, due to Significantly greater than Therefore, it can be determined that a voltage spurt has occurred in the ship's electrical system; a voltage spurt is a temporary increase in voltage. If Significantly smaller than Therefore, it can be determined that a voltage interruption has occurred in the ship's electrical system.

[0111] Please continue reading Figure 2 As shown, in step 204, the upper and lower envelope sequences are compared with the set Gaussian curve sequence through dynamic normalization to determine the degree of similarity, thereby identifying the specific type of power quality disturbance.

[0112] Please continue reading Figure 3 As shown, the power quality disturbance identification system of a ship's power system may include a disturbance type identification module 304, which can identify the specific power quality disturbance type by dynamically normalizing the upper and lower envelope sequences and the set Gaussian curve sequence to determine the degree of similarity.

[0113] Once the power quality disturbance categories in the power system are obtained, they can be pushed to users so that users can promptly diagnose ship faults based on the power quality disturbance categories and take timely measures to eliminate the faults.

[0114] The following describes an embodiment of the apparatus described in this application, which can be used to execute the power quality disturbance identification method for ship electrical systems described in the above embodiments of this application. For details not disclosed in the apparatus embodiments of this application, please refer to the embodiments of the power quality disturbance identification method for ship electrical systems described above in this application.

[0115] Figure 7 A block diagram of a power quality disturbance identification device for a ship's electrical system according to an embodiment of this application is shown. (Refer to...) Figure 7 As shown, a power quality disturbance identification device 700 for a ship's electrical system according to an embodiment of this application includes: a voltage sequence acquisition unit 710, a determination and normalization unit 720, a similarity determination unit 730, and a disturbance category determination unit 740. The voltage sequence acquisition unit 710 is used to acquire the instantaneous bus voltage sequence of the power system, which includes multiple instantaneous bus voltage values; the determination and normalization unit 720 is used to determine the upper envelope sequence and the lower envelope sequence of the instantaneous bus voltage sequence, and to normalize the upper envelope sequence and the lower envelope sequence respectively to obtain the normalized upper envelope sequence and the normalized lower envelope sequence; the similarity determination unit 730 is used to determine the first similarity between the normalized upper envelope sequence and the predetermined Gaussian curve sequence and the second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence respectively; the disturbance category determination unit 740 is used to determine the power quality disturbance category in the power system based on the comparison result of the first similarity and the second similarity.

[0116] Optionally, based on the aforementioned scheme, the device further includes a disturbance determination unit; before determining the upper envelope sequence and lower envelope sequence of the instantaneous bus voltage sequence, the disturbance determination unit is used to: determine whether there is a disturbance in the power quality of the power system based on the instantaneous bus voltage sequence, wherein determining the upper envelope sequence and lower envelope sequence of the instantaneous bus voltage sequence is performed under the condition that there is a disturbance in the power quality of the power system.

[0117] Optionally, based on the aforementioned scheme, the disturbance determination unit is configured to: determine the rate of change sequence between adjacent elements of the instantaneous bus voltage sequence; determine the maximum rate of change between adjacent elements of the instantaneous bus voltage sequence based on the rate of change sequence; and determine whether a disturbance has occurred in the power quality of the power system based on the maximum rate of change.

[0118] Optionally, based on the aforementioned scheme, the similarity determination unit 730 is configured to: construct a first distance matrix between the normalized upper envelope sequence and the predetermined Gaussian curve sequence; determine a first minimum cumulative distance based on the first distance matrix, wherein the first minimum cumulative distance is used to measure the degree of difference between the normalized upper envelope sequence and the predetermined Gaussian curve sequence after optimal nonlinear time alignment; determine a first similarity between the normalized upper envelope sequence and the predetermined Gaussian curve sequence based on the first minimum cumulative distance, wherein the first similarity is negatively correlated with the first minimum cumulative distance; construct a second distance matrix between the normalized lower envelope sequence and the predetermined Gaussian curve sequence; determine a second minimum cumulative distance based on the second distance matrix, wherein the second minimum cumulative distance is used to measure the degree of difference between the normalized lower envelope sequence and the predetermined Gaussian curve sequence after optimal nonlinear time alignment; and determine a second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence based on the second minimum cumulative distance, wherein the second similarity is negatively correlated with the second minimum cumulative distance.

[0119] Optionally, based on the aforementioned scheme, the similarity determination unit 730 is configured to: construct a first cumulative distance matrix according to the first distance matrix, wherein each element in the first cumulative distance matrix is ​​used to measure the distance of the path with the smallest total distance among all possible paths from the element in the upper left corner to the current element; and determine a first minimum cumulative distance according to the first cumulative distance matrix.

[0120] Optionally, based on the aforementioned scheme, the determination and normalization unit 720 is configured to: perform a Hilbert transform on the instantaneous bus voltage sequence to obtain a discrete voltage sequence; construct a complex signal sequence based on the discrete voltage sequence and the instantaneous bus voltage sequence; construct an upper envelope sequence based on the complex signal sequence; and invert the upper envelope sequence to obtain a lower envelope sequence.

[0121] Optionally, based on the aforementioned scheme, the disturbance category determination unit 740 is configured as follows: if the first similarity is greater than the second similarity, the power quality disturbance category in the power system is determined to be a transient rise; if the difference between the first similarity and the second similarity is less than a predetermined difference threshold, the power quality disturbance category in the power system is determined to be a flicker; if the first similarity is less than the second similarity, the power quality disturbance category in the power system is determined to be an interruption.

[0122] Figure 8 A schematic diagram of the structure of a computer system suitable for implementing the electronic device of the present application is shown.

[0123] It should be noted that, Figure 8 The computer system 800 of the electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0124] like Figure 8 As shown, the computer system 800 includes a CPU 801, which can perform various appropriate actions and processes according to a program stored in ROM 802 or a program loaded into RAM 803 from storage portion 808, such as performing the methods described in the above embodiments. The RAM 803 also stores various programs and data required for system operation. The CPU 801, ROM 802, and RAM 803 are interconnected via bus 804. An I / O interface 805 is also connected to bus 804.

[0125] The following components are connected to I / O interface 805: an input section 806 including a keyboard, mouse, etc.; an output section 807 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 808 including a hard disk, etc.; and a communication section 809 including a network interface card such as a LAN (Local Area Network) card, modem, etc. The communication section 809 performs communication processing via a network such as the Internet. A drive 810 is also connected to I / O interface 805 as needed. A removable medium 811, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., is installed on drive 810 as needed so that computer programs read from it can be installed into storage section 808 as needed.

[0126] Specifically, according to embodiments of this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 809, and / or installed from removable medium 811. When the computer program is executed by CPU 801, it performs various functions defined in the system of this application.

[0127] It should be noted that the computer-readable medium shown in the embodiments of this application can be a computer-readable signal medium, a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fiber, portable compact disc read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such transmitted data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to wireless, wired, etc., or any suitable combination thereof.

[0128] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. Each block in a flowchart or block diagram may represent a module, segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0129] The units described in the embodiments of this application can be implemented in software or hardware, and the described units can also be located in a processor. The names of these units do not necessarily limit the specific unit itself.

[0130] In one aspect, this application also provides a computer-readable medium, which may be included in the electronic device described in the above embodiments; or it may exist independently and not assembled into the electronic device. The computer-readable medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to perform the methods described in the above embodiments.

[0131] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of this application, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0132] Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, touch terminal, or network device, etc.) to execute the methods according to the embodiments of this application.

[0133] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0134] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for identifying power quality disturbances in a ship's electrical system, characterized in that, include: Obtain the instantaneous bus voltage sequence of the power system, wherein the instantaneous bus voltage sequence includes multiple instantaneous bus voltage values; The upper envelope sequence and lower envelope sequence of the instantaneous voltage sequence of the bus are determined, and the upper envelope sequence and the lower envelope sequence are normalized respectively to obtain the normalized upper envelope sequence and the normalized lower envelope sequence. The first similarity between the normalized upper envelope sequence and the predetermined Gaussian curve sequence and the second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence are determined respectively. The power quality disturbance category in the power system is determined based on the comparison result of the first similarity and the second similarity.

2. The method for identifying power quality disturbances in a ship's electrical system according to claim 1, characterized in that, Before determining the upper and lower envelope sequences of the instantaneous bus voltage sequence, the method further includes: The determination of whether the power quality in the power system is disturbed is based on the instantaneous bus voltage sequence, wherein the determination of the upper envelope sequence and the lower envelope sequence of the instantaneous bus voltage sequence is performed under the condition that the power quality in the power system is disturbed.

3. The method for identifying power quality disturbances in a ship's electrical system according to claim 2, characterized in that, The step of determining whether there is a disturbance in the power quality of the power system based on the instantaneous bus voltage sequence includes: Determine the rate of change sequence between adjacent elements of the instantaneous bus voltage sequence; The maximum rate of change between adjacent elements of the instantaneous bus voltage sequence is determined based on the rate of change sequence; The power quality disturbance in the power system is determined based on the maximum rate of change.

4. The method for identifying power quality disturbances in a ship's electrical system according to claim 1, characterized in that, The determination of the first similarity between the normalized upper envelope sequence and the predetermined Gaussian curve sequence, and the second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence, respectively, includes: Construct a first distance matrix between the normalized upper envelope sequence and the predetermined Gaussian curve sequence; A first minimum cumulative distance is determined based on the first distance matrix. The first minimum cumulative distance is used to measure the degree of difference between the normalized upper envelope sequence and the predetermined Gaussian curve sequence after optimal nonlinear time alignment. The first similarity between the normalized upper envelope sequence and the predetermined Gaussian curve sequence is determined based on the first minimum cumulative distance, and the first similarity is negatively correlated with the first minimum cumulative distance. Construct a second distance matrix between the normalized lower envelope sequence and the predetermined Gaussian curve sequence; The second minimum cumulative distance is determined based on the second distance matrix. The second minimum cumulative distance is used to measure the degree of difference between the normalized lower envelope sequence and the predetermined Gaussian curve sequence after optimal nonlinear time alignment. The second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence is determined based on the second minimum cumulative distance, and the second similarity is negatively correlated with the second minimum cumulative distance.

5. The method for identifying power quality disturbances in a ship's electrical system according to claim 4, characterized in that, Determining the first minimum cumulative distance based on the first distance matrix includes: A first cumulative distance matrix is ​​constructed based on the first distance matrix. Each element in the first cumulative distance matrix is ​​used to measure the distance of the path with the smallest total distance among all possible paths from the top-left element to the current element. The first minimum cumulative distance is determined based on the first cumulative distance matrix.

6. The method for identifying power quality disturbances in a ship's electrical system according to claim 1, characterized in that, Determining the upper envelope sequence and lower envelope sequence of the instantaneous voltage sequence of the bus includes: Perform a Hilbert transform on the instantaneous voltage sequence of the bus to obtain a discrete voltage sequence; Construct a complex signal sequence based on the discrete voltage sequence and the instantaneous bus voltage sequence; Construct an upper envelope sequence based on the complex signal sequence; The upper envelope sequence is inverted to obtain the lower envelope sequence.

7. The method for identifying power quality disturbances in a ship's electrical system according to claim 1, characterized in that, Determining the power quality disturbance category in the power system based on the comparison result of the first similarity and the second similarity includes: If the first similarity is greater than the second similarity, then the power quality disturbance category in the power system is determined to be transient. If the difference between the first similarity and the second similarity is less than a predetermined difference threshold, then the power quality disturbance category in the power system is determined to be flicker. If the first similarity is less than the second similarity, then the power quality disturbance category in the power system is determined to be an interruption.

8. A power quality disturbance identification device for a ship's electrical system, characterized in that, The device includes: A voltage sequence acquisition unit is used to acquire the instantaneous bus voltage sequence of a power system, wherein the instantaneous bus voltage sequence includes multiple instantaneous bus voltage values; The determination and normalization unit is used to determine the upper envelope sequence and the lower envelope sequence of the instantaneous voltage sequence of the bus, and to normalize the upper envelope sequence and the lower envelope sequence respectively to obtain the normalized upper envelope sequence and the normalized lower envelope sequence. The similarity determination unit is used to determine the first similarity between the normalized upper envelope sequence and the predetermined Gaussian curve sequence and the second similarity between the normalized lower envelope sequence and the predetermined Gaussian curve sequence, respectively. The disturbance category determination unit is used to determine the power quality disturbance category in the power system based on the comparison result of the first similarity and the second similarity.

9. A computer-readable medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the power quality disturbance identification method for a ship's power system as described in any one of claims 1 to 7.

10. An electronic device, characterized in that, include: One or more processors; A storage device for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement the power quality disturbance identification method for a ship power system as described in any one of claims 1 to 7.

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