Phase sequence recognition device

Abstract

The application provides a phase sequence identification device, which comprises a voltage sampling unit and a voltage identification unit. The voltage sampling unit is used for collecting a multi-phase voltage vector of a high-voltage power distribution device of a power distribution network, and the multi-phase voltage vector comprises an A-phase voltage vector, a first voltage vector and a second voltage vector. The voltage identification unit is electrically connected with the voltage sampling unit. The voltage identification unit is used for performing phase shift processing on the phase of the first voltage vector and the phase of the second voltage vector to obtain corresponding first phase shift voltage vectors and second phase shift voltage vectors. The B-phase voltage vector and the C-phase voltage vector are determined according to the A-phase voltage vector, the first phase shift voltage vector and the second phase shift voltage vector. Thus, the purpose of determining the B-phase voltage vector and the C-phase voltage vector is achieved, and the problem that the existing scheme cannot determine the voltage phase sequence is solved.

Description

Technical Field

[0001] This application relates to the field of power distribution equipment technology, and more specifically, to a phase sequence identification device. Background Technology

[0002] Explosion-proof and intrinsically safe high-voltage vacuum switchgear (hereinafter referred to as high-explosive switch) is an essential switching device for underground power supply in coal mines, and intelligent microcomputer integrated protector (hereinafter referred to as protector) is an indispensable component of the high-explosive switch. The main functions of the protector are: first, to automatically, quickly, and selectively disconnect faulty components from the power system when a power grid fault occurs, ensuring the safety of personnel and equipment, and preventing accidents from occurring and escalating, thus avoiding large-scale power outages in the coal mine; second, to promptly issue alarm signals for abnormal operation of the power grid and abnormal states of certain equipment, enabling rapid handling and restoration to normal operation; and third, to utilize accumulated big data from existing power supply for intelligent analysis, intelligent judgment, and prediction of early equipment faults, optimizing the operating environment and equipment configuration to achieve safe, reliable, and economical operation of underground electrical equipment. Simultaneously, it integrates data with the energy management platform to achieve energy consumption analysis, energy-saving analysis, and decision-making functions. The protector's multiple protection functions and the reliability of the original data acquisition all rely on correct voltage and current phase sequences. However, due to various reasons (short renovation time, unclear wire numbers, unclear drawings, etc.), incorrect wiring often occurs without the person noticing. When the switch is closed, heavy load equipment is started, or the downstream substation is energized, the data is found to be incorrect (power factor, active power, reactive power), causing some protection functions to fail, which in turn leads to inaccurate power data.

[0003] If the wiring sequence needs to be adjusted, a new power outage time must be applied for, the high-explosive switch cabinet door must be opened, the wiring sequence must be sorted and adjusted. In the actual power supply situation in coal mines, many important loads cannot be disconnected after being switched on. At this time, intelligent microcomputer integrated protection devices are required to have an online automatic identification and adjustment method for voltage and current phase sequence. They can automatically adjust to the correct phase sequence without power outage / production disruption, ensuring safe and efficient production in coal mines and meeting the increasingly modern, digital, and information-based needs of coal mines.

[0004] The existing technical solutions have the following drawbacks: 1. The phase sequence adjustment scheme using manual calculation relies heavily on the waveform recording data of the relay protection. However, most relay protection systems still do not support the acquisition and transmission of waveform recording data. 2. For underground power supply systems in coal mines, manually adjusting the wiring sequence requires applying for a power outage. Then, professional technicians open the high-explosive switch cabinet door to make adjustments within the specified outage time. After the adjustment is completed, it is not known whether the adjustment is correct. It can only be seen after the circuit is closed and the downstream heavy load starts running. This method is time-consuming and labor-intensive, and there is also a possibility of making the adjustment again incorrectly. 3. The scheme of manually adjusting the protection device sampling channel locally requires the microcomputer protection to support this function. It also requires technicians to go down into the mine to make adjustments locally, which cannot meet the current needs of coal mine power supply systems for informatization, intelligence, and unmanned operation.

[0005] Currently, the explosion-proof and intrinsically safe high-voltage vacuum power distribution device for mining only has two phases, A and C, built-in. It is generally assumed that the voltage connection of phase A is not a problem, but the voltage of phase B and phase C cannot be confirmed.

[0006] The existing scheme cannot determine the current phase sequence and voltage phase sequence, that is, the existing scheme cannot determine the voltage phase sequence and current phase sequence. Summary of the Invention

[0007] The main objective of this application is to provide a phase sequence identification device to at least solve the problem that existing solutions cannot determine the voltage phase sequence.

[0008] To achieve the above objectives, according to one aspect of this application, a phase sequence identification device is provided, comprising a voltage sampling unit and a voltage identification unit; the voltage sampling unit is used to acquire multi-phase voltage vectors of a high-voltage distribution device in a power distribution network, wherein the multi-phase voltage vectors are an A-phase voltage vector, a first voltage vector, and a second voltage vector; the voltage identification unit is electrically connected to the voltage sampling unit, and the voltage identification unit is used to perform phase-shifting processing on the phases of the first voltage vector and the second voltage vector to obtain corresponding first phase-shifted voltage vectors and second phase-shifted voltage vectors, and to determine the B-phase voltage vector and the C-phase voltage vector based on the A-phase voltage vector, the first phase-shifted voltage vector, and the second phase-shifted voltage vector.

[0009] Optionally, the phase sequence identification device further includes a current sampling unit and a current identification unit. The current sampling unit is used to collect multi-phase current vectors of the high-voltage distribution device of the distribution network. The multi-phase current vectors are a first current vector and a second current vector, respectively. The first input terminal of the current identification unit is electrically connected to the current sampling unit, and the second input terminal of the current identification unit is used to receive the A-phase voltage vector. The current identification unit is used to perform phase-shifting processing on the first current vector and the second current vector to obtain a first phase-shifted current vector and a second phase-shifted current vector. Based on the A-phase voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector, the A-phase current vector and the C-phase current vector are determined.

[0010] Optionally, the phase sequence identification device further includes a phase sequence adjustment unit and a phase sequence storage unit; the input terminal of the phase sequence adjustment unit is electrically connected to the output terminal of the voltage identification unit and the output terminal of the current identification unit, respectively, and the phase sequence adjustment unit is used to adjust the phase of the voltage vector collected by the voltage sampling unit and the phase of the current vector collected by the current sampling unit; the phase sequence storage unit is electrically connected to the output terminal of the phase sequence adjustment unit, and the phase sequence storage unit is used to store the phase of the voltage vector and the phase of the current vector after adjustment by the phase sequence adjustment unit.

[0011] Optionally, determining the phase B voltage vector and phase C voltage vector based on the phase A voltage vector, the first phase-shifted voltage vector, and the second phase-shifted voltage vector includes: determining a first voltage characteristic value and a second voltage characteristic value based on the phase A voltage vector, the first phase-shifted voltage vector, and the second phase-shifted voltage vector, wherein the first voltage characteristic value is a characteristic value between the first phase-shifted voltage vector and the phase A voltage vector, and the second voltage characteristic value is a characteristic value between the second phase-shifted voltage vector and the phase A voltage vector; if the absolute value of the first voltage characteristic value is less than the absolute value of the second voltage characteristic value, determining the first voltage vector as the phase B voltage vector and determining the second voltage vector as the phase C voltage vector; if the absolute value of the first voltage characteristic value is greater than the absolute value of the second voltage characteristic value, determining the first voltage vector as the phase C voltage vector and determining the second voltage vector as the phase B voltage vector.

[0012] Optionally, after determining that the first voltage vector is the B-phase voltage vector and the second voltage vector is the C-phase voltage vector, the voltage identification unit is further configured to perform: phase shifting processing on the phase of the first phase-shifted voltage vector and the phase of the second phase-shifted voltage vector to obtain a third phase-shifted voltage vector and a fourth phase-shifted voltage vector; determining a third voltage characteristic value and a fourth voltage characteristic value based on the A-phase voltage vector, the third phase-shifted voltage vector, and the fourth phase-shifted voltage vector, wherein the third voltage characteristic value is a characteristic value between the third phase-shifted voltage vector and the A-phase voltage vector, and the fourth voltage characteristic value is a characteristic value between the fourth phase-shifted voltage vector and the A-phase voltage vector; if the absolute value of the third voltage characteristic value is less than the absolute value of the fourth voltage characteristic value, the judgment result is a correct result, wherein the judgment result determines that the first voltage vector is the B-phase voltage vector and the second voltage vector is the C-phase voltage vector.

[0013] Optionally, determining the A-phase current vector based on the A-phase voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector includes: determining a first current characteristic value and a second current characteristic value based on the A-phase voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector, wherein the first current characteristic value is a characteristic value between the first phase-shifted current vector and the A-phase voltage vector, and the second current characteristic value is a characteristic value between the second phase-shifted current vector and the A-phase voltage vector; if the absolute value of the first current characteristic value is less than a threshold value, determining the first current vector as the A-phase current vector, and then comparing the first phase-shifted current vector with the second phase-shifted current vector... The two phase-shifted current vectors are phase-shifted to obtain a third phase-shifted current vector and a fourth phase-shifted current vector. If the absolute value of the second current characteristic value is less than the threshold value, the second current vector is determined to be the A-phase current vector, and the first and second phase-shifted current vectors are phase-shifted to obtain the third and fourth phase-shifted current vectors. If the absolute value of the first current characteristic value is greater than the threshold value, and the absolute value of the second current characteristic value is greater than the threshold value, the first and second phase-shifted current vectors are phase-shifted to obtain the third and fourth phase-shifted current vectors.

[0014] Optionally, determining the C-phase current vector based on the A-phase voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector includes: performing phase-shifting processing on the first phase-shifted current vector and the second phase-shifted current vector to obtain a third phase-shifted current vector and a fourth phase-shifted current vector; determining a third current characteristic value and a fourth current characteristic value based on the A-phase voltage vector, the third phase-shifted current vector, and the fourth phase-shifted current vector, wherein the third current characteristic value is the characteristic value between the third phase-shifted current vector and the A-phase voltage vector, and the fourth current characteristic value is the characteristic value between the fourth phase-shifted current vector and the A-phase voltage vector; and determining the first current vector as the C-phase current vector if the absolute value of the third current characteristic value is less than a threshold value. The reverse sampling value of the phase current vector is used to perform phase shifting processing on the third and fourth phase-shifted current vectors to obtain the fifth and sixth phase-shifted current vectors; if the absolute value of the fourth current characteristic value is less than the threshold value, the second current vector is determined as the reverse sampling value of the C-phase current vector, and the third and fourth phase-shifted current vectors are subjected to phase shifting processing to obtain the fifth and sixth phase-shifted current vectors; if the absolute value of the third current characteristic value is greater than the threshold value, and the absolute value of the fourth current characteristic value is greater than the threshold value, the third and fourth phase-shifted current vectors are subjected to phase shifting processing to obtain the fifth and sixth phase-shifted current vectors.

[0015] Optionally, determining the phase A current vector based on the phase A voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector includes: performing phase-shifting processing on the first phase-shifted current vector and the second phase-shifted current vector to obtain a third phase-shifted current vector and a fourth phase-shifted current vector, and performing phase-shifting processing on the third phase-shifted current vector and the fourth phase-shifted current vector to obtain a fifth phase-shifted current vector and a sixth phase-shifted current vector; determining a fifth current characteristic value and a sixth current characteristic value based on the phase A voltage vector, the fifth phase-shifted current vector, and the sixth phase-shifted current vector, wherein the fifth current characteristic value is the characteristic value between the fifth phase-shifted current vector and the phase A voltage vector, and the sixth current characteristic value is the characteristic value between the sixth phase-shifted current vector and the phase A voltage vector; and determining the characteristic value between the sixth phase-shifted current vector and the phase A voltage vector based on the absolute value of the fifth current characteristic value being less than a threshold value. Under the condition of a threshold, the first current vector is determined to be the reverse sampled value of the A-phase current vector, and the fifth and sixth phase-shifted current vectors are subjected to phase-shifting processing to obtain the seventh and eighth phase-shifted current vectors; if the absolute value of the sixth current characteristic value is less than the threshold value, the second current vector is determined to be the reverse sampled value of the A-phase current vector, and the fifth and sixth phase-shifted current vectors are subjected to phase-shifting processing to obtain the seventh and eighth phase-shifted current vectors; if the absolute value of the fifth current characteristic value is greater than the threshold value, and the absolute value of the sixth current characteristic value is greater than the threshold value, the fifth and sixth phase-shifted current vectors are subjected to phase-shifting processing to obtain the seventh and eighth phase-shifted current vectors.

[0016] Optionally, determining the phase C current vector based on the phase A voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector includes: performing phase-shifting processing on the first phase-shifted current vector and the second phase-shifted current vector to obtain a third phase-shifted current vector and a fourth phase-shifted current vector; performing phase-shifting processing on the third phase-shifted current vector and the fourth phase-shifted current vector to obtain a fifth phase-shifted current vector and a sixth phase-shifted current vector; and performing phase-shifting processing on the fifth phase-shifted current vector and the sixth phase-shifted current vector to obtain a seventh phase-shifted current vector and an eighth phase-shifted current vector; based on the phase A voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector, determining the phase C current vector includes: performing phase-shifting processing on the first phase-shifted current vector and the second phase-shifted current vector to obtain a third phase-shifted current vector and a fourth phase-shifted current vector; performing phase-shifting processing on the third phase-shifted current vector and the fourth phase-shifted current vector to obtain a fifth phase-shifted current vector and a sixth phase-shifted current vector; and performing phase-shifting processing on the fifth phase-shifted current vector and the sixth phase-shifted current vector to obtain a seventh phase-shifted current vector and an eighth phase-shifted current vector; based on the phase A voltage vector, the second phase C current vector is determined to be ... The voltage vector, the seventh phase-shifting current vector, and the eighth phase-shifting current vector are used to determine the seventh current characteristic value and the eighth current characteristic value. The seventh current characteristic value is the characteristic value between the fifth phase-shifting current vector and the A-phase voltage vector, and the eighth current characteristic value is the characteristic value between the eighth phase-shifting current vector and the A-phase voltage vector. If the absolute value of the seventh current characteristic value is less than a threshold value, the first current vector is determined to be the C-phase current vector. If the absolute value of the eighth current characteristic value is less than the threshold value, the second current vector is determined to be the C-phase current vector.

[0017] Optionally, after determining that the first current vector is the reverse sampled value of the C-phase current vector, the current identification unit is further configured to perform the following steps: process the first current vector to obtain a mirrored first current vector; use the mirrored first current vector as the C-phase current vector; after determining that the second current vector is the reverse sampled value of the C-phase current vector, the current identification unit is further configured to perform the following steps: process the second current vector to obtain a mirrored second current vector; use the mirrored second current vector as the C-phase current vector.

[0018] By applying the technical solution of this application, the phases of the first voltage vector and the second voltage vector are phase-shifted to obtain the corresponding first phase-shifted voltage vector and second phase-shifted voltage vector. Based on the A-phase voltage vector, the first phase-shifted voltage vector, and the second phase-shifted voltage vector, the B-phase voltage vector and the C-phase voltage vector are determined, thereby achieving the purpose of determining the B-phase voltage vector and the C-phase voltage vector, and thus solving the problem that the existing solution cannot determine the voltage phase sequence. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0020] Figure 1A schematic diagram of a phase sequence identification device provided in an embodiment of this application is shown;

[0021] Figure 2 A schematic diagram of the current vector with the phase A voltage vector Ua as the reference (horizontal axis) is shown;

[0022] Figure 3 A schematic diagram of another phase sequence identification device provided according to an embodiment of this application is shown.

[0023] The above figures include the following reference numerals:

[0024] 110 Voltage sampling unit; 120 Current sampling unit; 210 Voltage identification unit; 211 Voltage calculation unit; 212 PSEV unit; 220 Current identification unit; 221 Current calculation unit; 222 PSEC unit; 310 Phase sequence adjustment unit; 410 Phase sequence storage unit. Detailed Implementation

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this application described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] For ease of description, the following explains some of the nouns or terms used in the embodiments of this application:

[0029] PSEV, Phase Shift Eigenvalue Identification Method for Voltage, is a method for identifying the phase shift eigenvalues ​​of voltage.

[0030] PSEC, Phase Shift Eigenvalue Identification Method for Current, is a method for identifying the phase shift characteristics of current.

[0031] As described in the background section, current mine explosion-proof and intrinsically safe high-voltage vacuum power distribution devices only have two-phase current transformers, A and C. It is generally assumed that the voltage connection of phase A is not a problem, but the voltages of phase B and phase C cannot be confirmed. Existing solutions cannot determine the current phase sequence and voltage phase sequence. In other words, existing solutions cannot determine the voltage phase sequence and current phase sequence. To solve the problem that existing solutions cannot determine the voltage phase sequence, embodiments of this application provide a phase sequence identification device.

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0033] This application provides a phase sequence identification device, such as... Figure 1 As shown, the phase sequence identification device includes a voltage sampling unit 110 and a voltage identification unit 210. The voltage sampling unit 110 is used to collect multi-phase voltage vectors of the high-voltage distribution device in the power distribution network. The multi-phase voltage vectors are the A-phase voltage vector, the first voltage vector, and the second voltage vector. The voltage identification unit 210 is electrically connected to the voltage sampling unit 110. The voltage identification unit 210 is used to perform phase shifting processing on the phase of the first voltage vector and the phase of the second voltage vector to obtain the corresponding first phase-shifted voltage vector and the second phase-shifted voltage vector. Based on the A-phase voltage vector, the first phase-shifted voltage vector, and the second phase-shifted voltage vector, the B-phase voltage vector and the C-phase voltage vector are determined.

[0034] In the aforementioned phase sequence identification device, by performing phase-shifting processing on the phases of the first voltage vector and the second voltage vector, corresponding first and second phase-shifted voltage vectors are obtained. Based on the A-phase voltage vector, the first and second phase-shifted voltage vectors, the B-phase and C-phase voltage vectors are determined, thereby achieving the purpose of determining the B-phase and C-phase voltage vectors and solving the problem that existing solutions cannot determine the voltage phase sequence. The PSEV method is used to determine the B-phase and C-phase voltage vectors.

[0035] In one embodiment of this application, the phase sequence identification device further includes a current sampling unit 120 and a current identification unit 220. The current sampling unit 120 is used to collect multi-phase current vectors of the high-voltage power distribution device of the power distribution network. The multi-phase current vectors are a first current vector and a second current vector. The first input terminal of the current identification unit 220 is electrically connected to the current sampling unit 120. The second input terminal of the current identification unit 220 is used to receive the A-phase voltage vector. The current identification unit 220 is used to perform phase-shifting processing on the first current vector and the second current vector to obtain a first phase-shifted current vector and a second phase-shifted current vector. Based on the A-phase voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector, the A-phase current vector and the C-phase current vector are determined.

[0036] Specifically, the first and second current vectors are phase-shifted by the current identification unit to obtain the first and second phase-shifted current vectors. Based on the A-phase voltage vector, the first and second phase-shifted current vectors, the A-phase current vector and the C-phase current vector are determined, thus achieving the goal of determining the A-phase and C-phase current vectors and solving the problem that existing schemes cannot determine the current phase sequence. The PSEC method is used to determine the A-phase and C-phase current vectors.

[0037] In one embodiment of this application, the phase sequence identification device further includes a phase sequence adjustment unit 310 and a phase sequence storage unit 410; the input terminal of the phase sequence adjustment unit 310 is electrically connected to the output terminal of the voltage identification unit 210 and the output terminal of the current identification unit 220, respectively; the phase sequence adjustment unit 310 is used to adjust the phase of the voltage vector collected by the voltage sampling unit 110 and the phase of the current vector collected by the current sampling unit 120; the output terminal of the phase sequence adjustment unit 310 is electrically connected to the phase sequence storage unit 410, and the phase sequence storage unit 410 is used to store the phase of the voltage vector and the phase of the current vector after adjustment by the phase sequence adjustment unit 310.

[0038] Specifically, the phase sequence storage unit simultaneously feeds back the voltage phase sequence value and the current phase sequence value to the voltage identification unit and the current identification unit for calculation, thereby judging the rationality and correctness of the phase sequence adjustment scheme and achieving the effect of closed-loop verification.

[0039] In one embodiment of this application, determining the phase B voltage vector and the phase C voltage vector based on the phase A voltage vector, the first phase-shifted voltage vector, and the second phase-shifted voltage vector includes: determining a first voltage characteristic value and a second voltage characteristic value based on the phase A voltage vector, the first phase-shifted voltage vector, and the second phase-shifted voltage vector, wherein the first voltage characteristic value is a characteristic value between the first phase-shifted voltage vector and the phase A voltage vector, and the second voltage characteristic value is a characteristic value between the second phase-shifted voltage vector and the phase A voltage vector; if the absolute value of the first voltage characteristic value is less than the absolute value of the second voltage characteristic value, determining the first voltage vector as the phase B voltage vector and determining the second voltage vector as the phase C voltage vector; if the absolute value of the first voltage characteristic value is greater than the absolute value of the second voltage characteristic value, determining the first voltage vector as the phase C voltage vector and determining the second voltage vector as the phase B voltage vector.

[0040] The method for calculating eigenvalues ​​is as follows: [The text abruptly ends here, likely due to an incomplete sentence or a formatting error.] sum vector Perform a cross product, then divide the result by... vector magnitude sum The product of the magnitudes of vectors, and the formula is:

[0041]

[0042] Specifically, assuming the A-phase voltage wiring is correct, there is only one possibility for an incorrect voltage phase sequence: the B-phase and C-phase voltage wiring sequences are reversed. In this case, rotate the first and second voltage vectors counterclockwise by 120° (i.e., shift by +120°). Calculate the characteristic value λu1 between the first phase-shifted voltage vector (after the +120° phase shift) and the A-phase voltage vector.

[0043] And the characteristic value λu2 between the second phase-shifted voltage vector after the phase of the second voltage vector is +120° and the A-phase voltage vector, the absolute values ​​of the two characteristic values ​​are compared, and the characteristic value with the smaller absolute value corresponds to the true B-phase voltage, and the other phase is the C-phase voltage.

[0044] In one embodiment of this application, after determining that the first voltage vector is the B-phase voltage vector and the second voltage vector is the C-phase voltage vector, the voltage identification unit is further configured to perform: phase shifting processing on the phase of the first phase-shifted voltage vector and the phase of the second phase-shifted voltage vector to obtain a third phase-shifted voltage vector and a fourth phase-shifted voltage vector; determining a third voltage characteristic value and a fourth voltage characteristic value based on the A-phase voltage vector, the third phase-shifted voltage vector, and the fourth phase-shifted voltage vector, wherein the third voltage characteristic value is a characteristic value between the third phase-shifted voltage vector and the A-phase voltage vector, and the fourth voltage characteristic value is a characteristic value between the fourth phase-shifted voltage vector and the A-phase voltage vector; and determining that the judgment result is correct when the absolute value of the third voltage characteristic value is less than the absolute value of the fourth voltage characteristic value, wherein the judgment result is that the first voltage vector is the B-phase voltage vector and the second voltage vector is the C-phase voltage vector.

[0045] Specifically, to further confirm the correctness of the calculation results, the phase B voltage vector and the phase C voltage vector were rotated counterclockwise by 240° each. Taking the phase B voltage vector as the first voltage vector and the phase C voltage vector as the second voltage vector, the characteristic values ​​of the third phase-shifted voltage vector obtained after the phase of the first phase-shifted voltage vector is increased by 120° and compared with the phase A voltage vector were calculated again.

[0046] The characteristic values ​​of the fourth phase-shifted voltage vector obtained after the phase of the second phase-shifted voltage vector is increased by 120° and the characteristic value of the A-phase voltage vector are calculated. At this time, the absolute value of the latter characteristic value must be less than the absolute value of the former characteristic value. After calculating and comparing the characteristic values, the actual voltage channels of phase B and phase C can be obtained. Then, the phase sequence adjustment unit performs the corresponding phase sequence adjustment (phase sequence exchange) according to the calculation results, and stores and records the final phase sequence adjustment scheme in the phase sequence storage unit.

[0047] In one embodiment of this application, determining the A-phase current vector based on the aforementioned A-phase voltage vector, the aforementioned first phase-shifted current vector, and the aforementioned second phase-shifted current vector includes: determining a first current characteristic value and a second current characteristic value based on the aforementioned A-phase voltage vector, the aforementioned first phase-shifted current vector, and the aforementioned second phase-shifted current vector, wherein the first current characteristic value is a characteristic value between the aforementioned first phase-shifted current vector and the aforementioned A-phase voltage vector, and the second current characteristic value is a characteristic value between the aforementioned second phase-shifted current vector and the aforementioned A-phase voltage vector; if the absolute value of the aforementioned first current characteristic value is less than a threshold value, determining the aforementioned first current vector as the aforementioned A-phase current vector, and adjusting the aforementioned first phase-shifted current vector... The first and second phase-shifted current vectors are phase-shifted to obtain the third and fourth phase-shifted current vectors. If the absolute value of the second current characteristic value is less than the threshold value, the second current vector is determined to be the A-phase current vector, and the first and second phase-shifted current vectors are phase-shifted to obtain the third and fourth phase-shifted current vectors. If the absolute value of the first current characteristic value is greater than the threshold value, and the absolute value of the second current characteristic value is also greater than the threshold value, the first and second phase-shifted current vectors are phase-shifted to obtain the third and fourth phase-shifted current vectors.

[0048] Specifically, four angle values, α°, (α°+60°), (α°+180°), and (α°+240°), are selected as phase shift angle values. Assuming that the two currents obtained from the current sampling unit are Isa and Isc, the sampling currents Isa and Isc are first rotated counterclockwise by α degrees, that is, the phases of Isa and Isc are shifted forward by α degrees, resulting in two vectors, (Isa+α°) and (Isc+α°) (i.e., the first and second phase shift current vectors, respectively). Then, the eigenvalues ​​λa1 and λc1 of (Isa+α°) with respect to the phase voltage vector Ua are calculated respectively.

[0049] Due to the existence of actual sampling calculation errors, a threshold value of 0.1 is set here. If the absolute value of the characteristic value λa1, |λa1| < 0.1, then the sampled current Isa is the actual current of phase A. If the absolute value of the characteristic value λc1, |λc1| < 0.1, then the sampled current Isc is the actual current of phase A. If |λa1| > 0.1 and |λc1| > 0.1, then neither the sampled currents Isa nor Isc are the actual current of phase A, and further judgment is required.

[0050] In one embodiment of this application, determining the C-phase current vector based on the A-phase voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector includes: performing phase-shifting processing on the first and second phase-shifted current vectors to obtain a third and a fourth phase-shifted current vector; determining a third and a fourth current characteristic value based on the A-phase voltage vector, the third phase-shifted current vector, and the fourth phase-shifted current vector, wherein the third current characteristic value is the characteristic value between the third phase-shifted current vector and the A-phase voltage vector, and the fourth current characteristic value is the characteristic value between the fourth phase-shifted current vector and the A-phase voltage vector; and determining the first current vector if the absolute value of the third current characteristic value is less than a threshold value. Using the reverse sampled value of the aforementioned C-phase current vector, the aforementioned third and fourth phase-shifted current vectors are phase-shifted to obtain the fifth and sixth phase-shifted current vectors; if the absolute value of the aforementioned fourth current characteristic value is less than the aforementioned threshold value, the aforementioned second current vector is determined as the reverse sampled value of the aforementioned C-phase current vector, and the aforementioned third and fourth phase-shifted current vectors are phase-shifted to obtain the fifth and sixth phase-shifted current vectors; if the absolute value of the aforementioned third current characteristic value is greater than the aforementioned threshold value, and the absolute value of the aforementioned fourth current characteristic value is greater than the aforementioned threshold value, the aforementioned third and fourth phase-shifted current vectors are phase-shifted to obtain the fifth and sixth phase-shifted current vectors.

[0051] Specifically, the sampled currents Isa and Isc are rotated counterclockwise by (a+60) degrees, shifting their phases forward by (a+60) degrees to obtain two vectors: (Isa+a°+60°) and (Isc+a°+60°) (i.e., the third and fourth phase-shifted current vectors, respectively). Then, the eigenvalues ​​λa2 and λc2 of (Isa+a°+60°) with respect to the phase voltage vector Ua are calculated. Due to actual sampling calculation errors, a threshold value of 0.1 is set here. If the absolute value of the eigenvalue λa2 is |λa2| < 0.1, then the sampled current Isa is the reverse sampled value of the actual C-phase current. The sampled current needs to be mirrored to obtain the actual C-phase current. If the absolute value of the eigenvalue λc2 is |λc2| < 0.1, then the sampled current Isc is the reverse sampled value of the actual C-phase current. The sampled current needs to be mirrored to obtain the actual C-phase current. If |λa2| > 0.1 and |λc2| > 0.1, then neither the sampled currents Isa nor Isc are the reverse sampled values ​​of the actual C-phase current, and further judgment is required.

[0052] In one embodiment of this application, determining the phase A current vector based on the aforementioned phase A voltage vector, the aforementioned first phase-shifted current vector, and the aforementioned second phase-shifted current vector includes: performing phase-shifting processing on the aforementioned first phase-shifted current vector and the aforementioned second phase-shifted current vector to obtain a third phase-shifted current vector and a fourth phase-shifted current vector, and performing phase-shifting processing on the aforementioned third phase-shifted current vector and the aforementioned fourth phase-shifted current vector to obtain a fifth phase-shifted current vector and a sixth phase-shifted current vector; determining a fifth current characteristic value and a sixth current characteristic value based on the aforementioned phase A voltage vector, the aforementioned fifth phase-shifted current vector, and the aforementioned sixth phase-shifted current vector, wherein the fifth current characteristic value is the characteristic value between the aforementioned fifth phase-shifted current vector and the aforementioned phase A voltage vector, and the sixth current characteristic value is the characteristic value between the aforementioned sixth phase-shifted current vector and the aforementioned phase A voltage vector; and determining the absolute value of the aforementioned fifth current characteristic value. If the value is less than the threshold value, the first current vector is determined as the reverse sampled value of the A-phase current vector, and the fifth and sixth phase-shifted current vectors are phase-shifted to obtain the seventh and eighth phase-shifted current vectors; if the absolute value of the sixth current characteristic value is less than the threshold value, the second current vector is determined as the reverse sampled value of the A-phase current vector, and the fifth and sixth phase-shifted current vectors are phase-shifted to obtain the seventh and eighth phase-shifted current vectors; if the absolute value of both the fifth and sixth current characteristic values ​​is greater than the threshold value, the fifth and sixth phase-shifted current vectors are phase-shifted to obtain the seventh and eighth phase-shifted current vectors.

[0053] Specifically, the sampled currents Isa and Isc are rotated counterclockwise by (a+180) degrees, that is, the phases of Isa and Isc are shifted forward by (a+180) degrees, resulting in two vectors: (Isa+a°+180°) and (Isc+a°+180°) (i.e., the fifth and sixth phase-shifted current vectors, respectively). Then, the eigenvalues ​​λa3 of (Isa+a°+180°) with respect to the phase voltage vector Ua and λc3 of (Isc+a°+180°) with respect to Ua are calculated. Due to the existence of actual sampling calculation errors, a threshold value of 0.1 is set here. If the absolute value of the eigenvalue λa3 is |λa3| < 0.1, then the sampled current Isa is the reverse sampled value of the actual current of phase A. The sampled current needs to be mirrored to obtain the actual current of phase A. If the absolute value of the eigenvalue λc3 is |λc3| < 0.1, then the sampled current Isc is the reverse sampled value of the actual current of phase A. The sampled current needs to be mirrored to obtain the actual current of phase A. If |λa3| > 0.1 and |λc3| > 0.1, then neither the sampled currents Isa nor Isc are the reverse sampled values ​​of the actual current of phase A, and further judgment is required.

[0054] In one embodiment of this application, determining the phase C current vector based on the aforementioned phase A voltage vector, the aforementioned first phase-shifted current vector, and the aforementioned second phase-shifted current vector includes: performing phase-shifting processing on the aforementioned first phase-shifted current vector and the aforementioned second phase-shifted current vector to obtain a third phase-shifted current vector and a fourth phase-shifted current vector; performing phase-shifting processing on the aforementioned third phase-shifted current vector and the aforementioned fourth phase-shifted current vector to obtain a fifth phase-shifted current vector and a sixth phase-shifted current vector; and performing phase-shifting processing on the aforementioned fifth phase-shifted current vector and the aforementioned sixth phase-shifted current vector to obtain a seventh phase-shifted current vector and an eighth phase-shifted current vector; based on the above... The A-phase voltage vector, the seventh phase-shifting current vector, and the eighth phase-shifting current vector are described. A seventh current characteristic value and an eighth current characteristic value are determined. The seventh current characteristic value is the characteristic value between the fifth phase-shifting current vector and the A-phase voltage vector. The eighth current characteristic value is the characteristic value between the eighth phase-shifting current vector and the A-phase voltage vector. If the absolute value of the seventh current characteristic value is less than a threshold value, the first current vector is determined to be the C-phase current vector. If the absolute value of the eighth current characteristic value is less than the threshold value, the second current vector is determined to be the C-phase current vector.

[0055] Specifically, the sampled currents Isa and Isc are rotated counterclockwise by (a+240) degrees, that is, their phases are shifted forward by (a+240) degrees, resulting in two vectors (Isa+a+240) and (Isc+a+240) (i.e., the seventh and eighth phase-shifted current vectors, respectively). Then, the eigenvalues ​​λa4 and λc4 of (Isa+a°+240°) with respect to Ua are calculated. Due to the existence of actual sampling calculation errors, a threshold value of 0.1 is set here. If the absolute value of λa4, |λa4|, is less than 0.1, then the sampled current Isa is the actual current of phase C. If the absolute value of λc4, |λc4|, is less than 0.1, then the sampled current Isc is the actual current of phase C.

[0056] After the four-step phase shifting scheme, the actual current of phase A and the actual current of phase C can be obtained. Then, the phase sequence adjustment unit performs the corresponding phase sequence adjustment (phase sequence exchange or mirroring) according to the calculation results, and stores the final phase sequence adjustment scheme in the phase sequence storage unit.

[0057] like Figure 2 As shown, Figure 2 The diagram shows the current vector with the A-phase voltage vector Ua as the reference (horizontal axis). Current phase sequence errors are quite complex and can occur in several ways, mainly including the following:

[0058] The first scenario: The directions of phase A current and phase C current are correct, but the line sequence of phase A current and phase C current is reversed. Figure 2 In the example, I1 and I2, I1 corresponds to the sampling current of phase C and I2 corresponds to the sampling current of phase A. In practice, their phase sequence should be swapped, that is, I1 is the current of phase A and I2 is the current of phase C.

[0059] The second scenario: The wiring sequence of phase A current and phase C current is correct, but the wiring direction of phase A current is incorrect, while the wiring direction of phase C current is correct. Figure 2 In the diagram, I3 and I2 correspond to the sampling current of phase C and phase A, respectively. Since the current of phase C is correct, I2 is the actual current of phase C. The sampling current of phase A is 180° out of phase with the actual current, so it needs to be mirrored. Therefore, the actual current of phase A is -I3.

[0060] The third scenario: The wiring sequence of phase A current and phase C current is correct, the wiring direction of phase A current is correct, but the wiring direction of phase C current is incorrect. Figure 2 In the sampled currents I1 and I4, I1 corresponds to the sampled current of phase A and I4 corresponds to the sampled current of phase C. Since the current of phase A is correct, I1 is the actual current of phase A. The sampled current of phase C is 180° out of phase with the actual current, so it needs to be mirrored. That is, the actual current of phase C is -I4.

[0061] The fourth scenario: The wiring sequence of phase A current and phase C current is correct, but the wiring direction of phase A current is incorrect, and the wiring direction of phase C current is also incorrect. Figure 2 In the diagram, I3 corresponds to the sampling current of phase A, and I4 corresponds to the sampling current of phase C. The phase A sampling current is 180° out of phase with the actual current, so it needs to be mirrored, i.e., the actual current of phase A is -I3. The phase C sampling current is 180° out of phase with the actual current, so it needs to be mirrored, i.e., the actual current of phase C is -I4.

[0062] The fifth scenario: The wiring sequence of phase A current and phase C current is incorrect; the wiring direction of phase A current is incorrect; the wiring direction of phase C current is incorrect, such as... Figure 2 In the diagram, I4 corresponds to the sampling current of phase A, and I3 corresponds to the sampling current of phase C. Because both the phase A and phase C currents have incorrect wiring sequences and directions, it is necessary to adjust the wiring sequence of phase A and phase C, and then mirror them separately. Finally, the actual current of phase A is -I3, and the actual current of phase C is -I4. Finally, there is a completely correct wiring method, where the wiring sequence and directions are both correct. In this case, I1 is both the sampling current of phase A and the actual current of phase A, and I2 is both the sampling current of phase C and the actual current of phase C.

[0063] like Figure 2 As shown, assume that the I1 current lags behind the Ua phase voltage by an angle α, meaning the angle between the I1 current and the Ua phase voltage is (-α) degrees; the I2 current lags behind the Uc (i.e., the C phase voltage vector) by an angle α, meaning the angle between the I2 current and the Uc phase voltage is (-α) degrees, and the angle between the I2 current and the Ua phase voltage is (-α - 240) degrees; the I3 current differs from the I1 current by 180°, meaning the angle between the I3 current and the Ua phase voltage is (-α - 180) degrees; the I4 current differs from the I2 current by 180°, meaning the angle between the I4 current and the Ua phase voltage is (-α - 240 + 180) degrees. Therefore, we can also derive that the angle between the I1 current and the I4 current is 60°, the angle between the I4 current and the I3 current is 120°, and the angle between the I3 current and the I2 current is 60°.

[0064] In one embodiment of this application, after determining that the first current vector is the reverse sampled value of the C-phase current vector, the current identification unit is further configured to perform the following steps: processing the first current vector to obtain a mirrored first current vector; using the mirrored first current vector as the C-phase current vector; after determining that the second current vector is the reverse sampled value of the C-phase current vector, the current identification unit is further configured to perform the following steps: processing the second current vector to obtain a mirrored second current vector; using the mirrored second current vector as the C-phase current vector.

[0065] Specifically, the subsequent processing method for the reverse sampled value of the A-phase current vector is similar. Here, only the reverse sampled value of the C-phase current vector is described. The subsequent processing method for the reverse sampled value of the A-phase current vector will not be repeated. After determining that the first current vector is the reverse sampled value of the C-phase current vector, the first current vector is processed to obtain the mirrored first current vector. The mirrored first current vector is used as the C-phase current vector. After determining that the second current vector is the reverse sampled value of the C-phase current vector, the second current vector is processed to obtain the mirrored second current vector. The mirrored second current vector is used as the C-phase current vector, thereby determining the C-phase current vector.

[0066] The phase sequence identification device solves the problem of incorrect voltage or current wiring caused by human error during the installation or replacement of the intelligent microcomputer integrated protector built into the explosion-proof and intrinsically safe high-voltage vacuum power distribution device in coal mines. This leads to discrepancies between the voltage and current sampling channel data and the actual values, resulting in inaccurate analog values ​​for subsequent measurement and calculation, as well as inaccurate analog values ​​for protection calculation. In severe cases, this may cause the protector to malfunction or fail to operate during a real fault.

[0067] Based on the PSEV voltage phase shift characteristic value identification method and the PSEC current phase shift characteristic value identification method, online microprocessor-based phase sequence identification and adjustment of microprocessor-based protection devices was achieved. Compared with existing phase sequence adjustment methods, which rely on expert calculations and manual adjustment of voltage and current wiring sequences underground, this method enables automatic identification and adjustment of the voltage and current phase sequences of microprocessor-based protection devices. Furthermore, it eliminates the need for high-voltage power distribution device tripping and power outages, and requires no manual intervention, achieving online identification and adjustment. This significantly reduces the tripping and power outage time of high-voltage power distribution devices and ensures the safety of underground power supply equipment in coal mines.

[0068] This application also provides another phase sequence identification device, such as Figure 3 As shown, the phase sequence identification device consists of a voltage sampling unit 110, a current sampling unit 120, a voltage calculation unit 211, a current calculation unit 221, a PSEV unit 212, a PSEC unit 222, a phase sequence adjustment unit 310, and a phase sequence storage unit 410.

[0069] The voltage sampling unit is used to sample the three-phase voltage data of the power supply system (A, B, C) in real time after passing through the PT (voltage transformer). Taking 32-point sampling as an example, three array spaces of 32 are opened in the data area to store the voltage sampling values ​​in real time. The sampling values ​​in the array spaces are updated in real time through a loop, so that the sampling values ​​in the array spaces are always the latest sampling values. The sampling values ​​in the array spaces are shared with the voltage calculation unit data, which facilitates calculation.

[0070] The current sampling unit is used to sample the AC two-phase current data in the power supply system in real time after passing through the CT (current transformer). (Currently, high-voltage vacuum power distribution devices only have AC two-phase CTs). The current is also sampled at 32 points. Two array spaces of 32 are opened in the data area to store the current sampling values ​​in real time. The sampling values ​​in the array spaces are updated in real time through a loop, so that the sampling values ​​in the array spaces are always the latest sampling values. The sampling values ​​in the array spaces are shared with the current calculation unit for easy calculation.

[0071] The voltage calculation unit is used to perform real-time calculations based on the three-phase voltage sampling values ​​in the data space. Here, the voltage phase sequence value sent by the phase sequence storage unit is first used to perform DFT calculation to obtain the real part, imaginary part, and effective value of each phase voltage. Based on the calculation results, it is determined whether voltage phase sequence adjustment is required. If voltage phase sequence adjustment is required, the calculated value is sent to the PSEV unit for analysis and judgment. If no adjustment is required, the PESV unit is skipped.

[0072] The current calculation unit is used to perform real-time calculations based on the two-phase current sampling values ​​in the data space. Here, the current phase sequence values ​​sent by the phase sequence storage unit are used to perform DFT calculations to obtain the real and imaginary parts, effective values, power, and power factor of the A and C phase currents, respectively. Based on the calculation results, it is determined whether current phase sequence adjustment is required. If current phase sequence adjustment is required, the calculated values ​​are sent to the PSEC unit for analysis and judgment. If no adjustment is required, the PSEC unit is skipped.

[0073] The function of the PSEV unit is to analyze and judge the various values ​​sent by the voltage calculation unit to obtain the final voltage phase sequence value. The PSEV unit uses a voltage phase shift characteristic value identification method for judgment, which can effectively identify the actual voltage phase sequence value. The PSEV unit sends the identified voltage phase sequence value to the phase sequence adjustment unit.

[0074] The PSEC unit analyzes and judges the various values ​​sent by the current calculation unit to obtain the final current phase sequence value. The PSEC unit uses a current phase shift characteristic value identification method to judge, which can effectively identify the actual current phase sequence value. The PSEC unit sends the identified current phase sequence value to the phase sequence adjustment unit.

[0075] The phase sequence adjustment unit selects an appropriate adjustment scheme based on the voltage phase sequence value identified by the PSEV unit and the current phase sequence value identified by the PSEC unit, and reasonably adjusts the sampling channel and the sampled value to ensure that the sampled value is consistent with the actual value. The phase sequence adjustment unit then sends the adjusted phase sequence value to the phase sequence storage unit.

[0076] The main function of the phase sequence storage unit is to store the voltage phase sequence value and current phase sequence value sent by the phase sequence adjustment unit. At the same time, the phase sequence storage unit feeds back the voltage phase sequence value and current phase sequence value to the voltage calculation unit and current calculation unit respectively for calculation, thereby judging the rationality and correctness of the phase sequence adjustment scheme and achieving the effect of closed-loop verification.

[0077] It should be noted that the above electrical connection can be a direct electrical connection or an indirect electrical connection. A direct electrical connection means that two devices are directly connected, while an indirect electrical connection means that there are other devices such as capacitors and resistors connected between the connected A and B.

[0078] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0079] As can be seen from the above description, the embodiments of this application achieve the following technical effects:

[0080] The phase sequence identification device of this application obtains the corresponding first phase-shifted voltage vector and second phase-shifted voltage vector by performing phase-shifting processing on the phase of the first voltage vector and the phase of the second voltage vector. Based on the A-phase voltage vector, the first phase-shifted voltage vector and the second phase-shifted voltage vector, the B-phase voltage vector and the C-phase voltage vector are determined, thereby achieving the purpose of determining the B-phase voltage vector and the C-phase voltage vector, and thus solving the problem that the existing solution cannot determine the voltage phase sequence.

[0081] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A phase sequence identification device, characterized in that, include: A voltage sampling unit is used to collect multi-phase voltage vectors of high-voltage distribution devices in a power distribution network. The multi-phase voltage vectors are A-phase voltage vector, first voltage vector, and second voltage vector. A voltage identification unit is electrically connected to the voltage sampling unit. The voltage identification unit is used to perform phase shifting processing on the phase of the first voltage vector and the phase of the second voltage vector to obtain the corresponding first phase-shifted voltage vector and second phase-shifted voltage vector. Based on the A-phase voltage vector, the first phase-shifted voltage vector and the second phase-shifted voltage vector, the B-phase voltage vector and the C-phase voltage vector are determined. The phase sequence identification device further includes a current sampling unit and a current identification unit. The current sampling unit is used to collect multi-phase current vectors of the high-voltage distribution device of the distribution network. The multi-phase current vectors are a first current vector and a second current vector, respectively. The first input terminal of the current identification unit is electrically connected to the current sampling unit, and the second input terminal of the current identification unit is used to receive the A-phase voltage vector. The current identification unit is used to perform phase-shifting processing on the first current vector and the second current vector to obtain a first phase-shifted current vector and a second phase-shifted current vector. Based on the A-phase voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector, the A-phase current vector and the C-phase current vector are determined.

2. The phase sequence identification device according to claim 1, characterized in that, The phase sequence identification device further includes: A phase sequence adjustment unit, wherein the input terminal of the phase sequence adjustment unit is electrically connected to the output terminal of the voltage identification unit and the output terminal of the current identification unit, respectively, and the phase sequence adjustment unit is used to adjust the phase of the voltage vector acquired by the voltage sampling unit and the phase of the current vector acquired by the current sampling unit; A phase sequence storage unit is electrically connected to the output terminal of the phase sequence adjustment unit. The phase sequence storage unit is used to store the phase of the voltage vector and the phase of the current vector after being adjusted by the phase sequence adjustment unit.

3. The phase sequence identification device according to claim 1, characterized in that, Based on the A-phase voltage vector, the first phase-shifted voltage vector, and the second phase-shifted voltage vector, the B-phase voltage vector and the C-phase voltage vector are determined, including: Based on the A-phase voltage vector, the first phase-shifted voltage vector, and the second phase-shifted voltage vector, a first voltage characteristic value and a second voltage characteristic value are determined. The first voltage characteristic value is the characteristic value between the first phase-shifted voltage vector and the A-phase voltage vector, and the second voltage characteristic value is the characteristic value between the second phase-shifted voltage vector and the A-phase voltage vector. If the absolute value of the first voltage characteristic value is less than the absolute value of the second voltage characteristic value, the first voltage vector is determined to be the B-phase voltage vector, and the second voltage vector is determined to be the C-phase voltage vector. If the absolute value of the first voltage characteristic value is greater than the absolute value of the second voltage characteristic value, the first voltage vector is determined to be the C-phase voltage vector, and the second voltage vector is determined to be the B-phase voltage vector.

4. The phase sequence identification device according to claim 3, characterized in that, After determining that the first voltage vector is the B-phase voltage vector and the second voltage vector is the C-phase voltage vector, the voltage identification unit is further configured to perform: The phases of the first phase-shifted voltage vector and the second phase-shifted voltage vector are phase-shifted to obtain the third phase-shifted voltage vector and the fourth phase-shifted voltage vector. Based on the A-phase voltage vector, the third phase-shifted voltage vector, and the fourth phase-shifted voltage vector, a third voltage characteristic value and a fourth voltage characteristic value are determined. The third voltage characteristic value is the characteristic value between the third phase-shifted voltage vector and the A-phase voltage vector, and the fourth voltage characteristic value is the characteristic value between the fourth phase-shifted voltage vector and the A-phase voltage vector. If the absolute value of the third voltage characteristic value is less than the absolute value of the fourth voltage characteristic value, the judgment result is correct. The judgment result is that the first voltage vector is determined to be the B-phase voltage vector, and the second voltage vector is determined to be the C-phase voltage vector.

5. The phase sequence identification device according to claim 1, characterized in that, Determining the phase A current vector based on the phase A voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector includes: Based on the A-phase voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector, a first current characteristic value and a second current characteristic value are determined. The first current characteristic value is the characteristic value between the first phase-shifted current vector and the A-phase voltage vector, and the second current characteristic value is the characteristic value between the second phase-shifted current vector and the A-phase voltage vector. If the absolute value of the first current characteristic value is less than the threshold value, the first current vector is determined to be the A-phase current vector, and the first phase-shifted current vector and the second phase-shifted current vector are phase-shifted to obtain the third phase-shifted current vector and the fourth phase-shifted current vector. If the absolute value of the second current characteristic value is less than the threshold value, the second current vector is determined to be the A-phase current vector, and the first phase-shifted current vector and the second phase-shifted current vector are subjected to phase-shifting processing to obtain the third phase-shifted current vector and the fourth phase-shifted current vector. If the absolute value of the first current characteristic value is greater than the threshold value, and the absolute value of the second current characteristic value is greater than the threshold value, the first phase-shifted current vector and the second phase-shifted current vector are subjected to phase-shifting processing to obtain the third phase-shifted current vector and the fourth phase-shifted current vector.

6. The phase sequence identification device according to claim 1, characterized in that, Determining the phase C current vector based on the phase A voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector includes: The first phase-shifted current vector and the second phase-shifted current vector are subjected to phase-shifting processing to obtain the third phase-shifted current vector and the fourth phase-shifted current vector; Based on the A-phase voltage vector, the third phase-shifting current vector, and the fourth phase-shifting current vector, a third current characteristic value and a fourth current characteristic value are determined. The third current characteristic value is the characteristic value between the third phase-shifting current vector and the A-phase voltage vector, and the fourth current characteristic value is the characteristic value between the fourth phase-shifting current vector and the A-phase voltage vector. If the absolute value of the third current characteristic value is less than the threshold value, the first current vector is determined to be the reverse sample value of the C-phase current vector. The third phase-shifted current vector and the fourth phase-shifted current vector are subjected to phase-shifting processing to obtain the fifth phase-shifted current vector and the sixth phase-shifted current vector. If the absolute value of the fourth current characteristic value is less than the threshold value, the second current vector is determined to be the reverse sample value of the C-phase current vector, and the third and fourth phase-shifted current vectors are phase-shifted to obtain the fifth and sixth phase-shifted current vectors. If the absolute value of the third current characteristic value is greater than the threshold value, and the absolute value of the fourth current characteristic value is greater than the threshold value, the third phase-shifted current vector and the fourth phase-shifted current vector are subjected to phase-shifting processing to obtain the fifth phase-shifted current vector and the sixth phase-shifted current vector.

7. The phase sequence identification device according to claim 1, characterized in that, Determining the phase A current vector based on the phase A voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector includes: The first phase-shifted current vector and the second phase-shifted current vector are phase-shifted to obtain the third phase-shifted current vector and the fourth phase-shifted current vector, and the third phase-shifted current vector and the fourth phase-shifted current vector are phase-shifted to obtain the fifth phase-shifted current vector and the sixth phase-shifted current vector. Based on the A-phase voltage vector, the fifth phase-shifting current vector, and the sixth phase-shifting current vector, the fifth current characteristic value and the sixth current characteristic value are determined. The fifth current characteristic value is the characteristic value between the fifth phase-shifting current vector and the A-phase voltage vector, and the sixth current characteristic value is the characteristic value between the sixth phase-shifting current vector and the A-phase voltage vector. If the absolute value of the fifth current characteristic value is less than the threshold value, the first current vector is determined to be the reverse sampled value of the A-phase current vector. The fifth phase-shifted current vector and the sixth phase-shifted current vector are subjected to phase-shifting processing to obtain the seventh phase-shifted current vector and the eighth phase-shifted current vector. If the absolute value of the sixth current characteristic value is less than the threshold value, the second current vector is determined to be the reverse sample value of the A-phase current vector, and the fifth and sixth phase-shifted current vectors are subjected to phase-shifting processing to obtain the seventh and eighth phase-shifted current vectors. If the absolute value of the fifth current characteristic value is greater than the threshold value, and the absolute value of the sixth current characteristic value is greater than the threshold value, the fifth phase-shifting current vector and the sixth phase-shifting current vector are subjected to phase-shifting processing to obtain the seventh phase-shifting current vector and the eighth phase-shifting current vector.

8. The phase sequence identification device according to claim 1, characterized in that, Determining the phase C current vector based on the phase A voltage vector, the first phase-shifted current vector, and the second phase-shifted current vector includes: The first phase-shifted current vector and the second phase-shifted current vector are phase-shifted to obtain the third phase-shifted current vector and the fourth phase-shifted current vector. The third phase-shifted current vector and the fourth phase-shifted current vector are phase-shifted to obtain the fifth phase-shifted current vector and the sixth phase-shifted current vector. The fifth phase-shifted current vector and the sixth phase-shifted current vector are phase-shifted to obtain the seventh phase-shifted current vector and the eighth phase-shifted current vector. Based on the A-phase voltage vector, the seventh phase-shifting current vector, and the eighth phase-shifting current vector, determine the seventh current characteristic value and the eighth current characteristic value. The seventh current characteristic value is the characteristic value between the fifth phase-shifting current vector and the A-phase voltage vector, and the eighth current characteristic value is the characteristic value between the eighth phase-shifting current vector and the A-phase voltage vector. If the absolute value of the seventh current characteristic value is less than the threshold value, the first current vector is determined to be the C-phase current vector; If the absolute value of the eighth current characteristic value is less than the threshold value, the second current vector is determined to be the C-phase current vector.

9. The phase sequence identification device according to claim 6, characterized in that, After determining that the first current vector is the reverse sampled value of the C-phase current vector, the current identification unit is further configured to perform the following steps: The first current vector is processed to obtain the mirrored first current vector; The mirrored first current vector is taken as the C-phase current vector; After determining that the second current vector is the reverse sampled value of the C-phase current vector, the current identification unit is further configured to perform the following steps: The second current vector is processed to obtain the mirrored second current vector; The mirrored second current vector is used as the C-phase current vector.

Images