A detection method and device for high-low crossing working conditions and a medium

Abstract

The application discloses a high-low penetration working condition detection method and device and a medium, relates to the photovoltaic field, and is used for quickly calculating the amplitude of voltage to detect the high-low penetration working condition. Each line voltage instantaneous value of a three-phase alternating current signal is obtained. The phase voltage instantaneous value of each phase is obtained according to the line voltage instantaneous value. The positive and negative sequence separation is performed on the phase voltage instantaneous value of each phase to obtain the reconstructed phase voltage instantaneous value of each phase. Each reconstructed line voltage instantaneous value is obtained according to the reconstructed phase voltage instantaneous value of each phase. The corresponding line voltage amplitude is obtained according to the reconstructed line voltage instantaneous value. Whether the current is in a high voltage penetration state or a low voltage penetration state is judged through the line voltage amplitude. The three-phase voltage instantaneous value is reconstructed through the positive and negative sequence voltage, various different power grid working conditions can be adapted, the amplitude of three line voltages is calculated through the obtained instantaneous value, and the high-low penetration working condition can be quickly and accurately recognized.

Description

Technical Field

[0001] This application relates to the photovoltaic field, and in particular to a detection method, device, and medium for high and low ride conditions. Background Technology

[0002] Photovoltaic inverters are a crucial component of photovoltaic (PV) power generation systems. A two-stage PV inverter typically consists of a boost circuit and an inverter circuit. The boost circuit raises the low voltage output from the PV array to a stable high-voltage direct current (DC), which is then converted to alternating current (AC) by the inverter circuit and fed into the grid. Fault ride-through refers to the inverter's ability to maintain continuous operation without disconnecting from the grid within a specified range and time interval when the AC output voltage exceeds the normal operating range due to a power system fault or disturbance. High Voltage Ride Through (HVRT) refers to the ability of the PV inverter to maintain continuous operation without disconnecting from the grid and to provide dynamic reactive power to support grid recovery when the AC output voltage rises due to a power system fault or disturbance, within a certain voltage drop range and time interval. Low Voltage Ride Through (LVRT) refers to the ability of the PV inverter to maintain grid connection while providing reactive power support during periods of low voltage, especially when a significant voltage drop occurs during grid connection.

[0003] Existing technologies typically calculate the amplitude of each line voltage using a sliding window root mean square method. While this method is relatively simple, the results are updated slowly, making it difficult to quickly detect high-low crossing conditions.

[0004] Therefore, providing a method to quickly calculate the current voltage amplitude to detect high and low voltage crossing conditions is a technical problem that urgently needs to be solved by those in the field. Summary of the Invention

[0005] The purpose of this application is to provide a method, apparatus, and medium for detecting high and low ride-through conditions by rapidly calculating the amplitude of the current voltage.

[0006] To address the aforementioned technical problems, this application provides a detection method for high and low crossing conditions, comprising:

[0007] Obtain the instantaneous values ​​of the line voltages of the three-phase AC signal;

[0008] The instantaneous value of the phase voltage of each phase is obtained from the instantaneous value of each line voltage;

[0009] The instantaneous phase voltage values ​​of each phase are separated by positive and negative sequence to obtain the reconstructed instantaneous phase voltage values ​​of each phase;

[0010] The instantaneous values ​​of each reconstructed line voltage are obtained based on the instantaneous values ​​of the reconstructed phase voltage of each phase;

[0011] The corresponding line voltage amplitude is obtained based on the instantaneous values ​​of each reconstructed line voltage;

[0012] The line voltage amplitude is used to determine whether the current state is a high-voltage ride-through state or a low-voltage ride-through state.

[0013] Preferably, in the above-mentioned detection method for high-voltage and low-voltage ride-through conditions, determining whether the current state is a high-voltage ride-through state or a low-voltage ride-through state based on the line voltage amplitude includes:

[0014] Determine whether the minimum value among the three current line voltage amplitudes is less than the rated voltage of the first preset ratio;

[0015] If so, then it is determined that the system is in a low-voltage ride-through state.

[0016] Preferably, in the above-mentioned detection method for high-voltage and low-voltage ride-through conditions, determining whether the current state is a high-voltage ride-through state or a low-voltage ride-through state based on the line voltage amplitude includes:

[0017] Determine whether the maximum value among the three current line voltage amplitudes is greater than the rated voltage of the second preset ratio;

[0018] If so, then it is determined that the system is in a high-voltage ride-through state.

[0019] Preferably, in the above-mentioned detection method for high-voltage and low-voltage ride-through conditions, determining whether the current state is a high-voltage ride-through state or a low-voltage ride-through state based on the line voltage amplitude includes:

[0020] Determine whether the current three line voltage amplitudes decrease within a preset time and the difference is greater than the third preset ratio of the rated voltage;

[0021] If so, then it is determined that the system is in a low-voltage ride-through state.

[0022] Preferably, in the above-mentioned detection method for high and low voltage crossing conditions, obtaining the instantaneous phase voltage value of each phase based on the instantaneous line voltage value includes:

[0023] The instantaneous phase voltage values ​​of each phase are calculated based on the instantaneous values ​​of each line voltage and the first formula.

[0024] The first formula is:

[0025]

[0026] Among them, U a U is the instantaneous value of the phase voltage of phase A. b U is the instantaneous value of the phase voltage of phase B. c U is the instantaneous value of the phase voltage of phase C. abU is the instantaneous value of the line voltage between phase A and phase B. bc U is the instantaneous value of the line voltage between phases B and C. ca This represents the instantaneous line voltage between phases A and C.

[0027] Preferably, in the above-mentioned detection method for high and low crossover conditions, the instantaneous phase voltage values ​​of each phase are separated by positive and negative sequence to obtain the reconstructed instantaneous phase voltage values ​​of each phase, including:

[0028] The instantaneous phase voltage values ​​of each phase are separated into positive and negative sequences to obtain the positive sequence voltage d-axis component, positive sequence voltage q-axis component, negative sequence voltage d-axis component, and negative sequence voltage q-axis component.

[0029] The instantaneous values ​​of the reconstructed phase voltages for each phase are obtained according to the second formula;

[0030] The second formula is:

[0031]

[0032] Among them, U a1 U is the instantaneous value of the reconstructed phase voltage of phase A. b1 U is the instantaneous value of the reconstructed phase voltage of phase B. c1 U is the instantaneous value of the reconstructed phase voltage of phase C. p For positive sequence voltage, U n For the negative sequence voltage, ωt is the angle between the d-axis of the positive sequence voltage and the A-phase voltage, -ωt is the angle between the d-axis of the negative sequence voltage and the A-phase voltage, and θ is the angle between the q-axis of the positive sequence voltage and the d-axis of the negative sequence voltage.

[0033] Preferably, in the above-mentioned detection method for high-low crossing conditions, obtaining the instantaneous values ​​of each reconstructed line voltage based on the instantaneous values ​​of the reconstructed phase voltage of each phase includes:

[0034] The instantaneous values ​​of the reconstructed phase voltages of each phase are obtained from the instantaneous values ​​of the reconstructed line voltages and the third formula.

[0035] The third formula is:

[0036]

[0037] Among them, U ab1 U is the instantaneous value of the reconfiguration line voltage between phase A and phase B. bc1 U is the instantaneous value of the reconfiguration line voltage between phases B and C. ca1 This represents the instantaneous value of the reconstructed line voltage between phase C and phase A.

[0038] To address the aforementioned technical problems, this application also provides a detection device for high-altitude and low-altitude crossing conditions, comprising:

[0039] The acquisition module is used to acquire the instantaneous values ​​of the line voltages of the three-phase AC signal;

[0040] The first calculation module is used to obtain the instantaneous phase voltage value of each phase based on the instantaneous value of each line voltage;

[0041] The separation module is used to separate the instantaneous phase voltage values ​​of each phase into positive and negative sequences to obtain the reconstructed instantaneous phase voltage values ​​of each phase.

[0042] The second calculation module is used to obtain the instantaneous values ​​of each reconstructed line voltage based on the instantaneous values ​​of the reconstructed phase voltage of each phase;

[0043] The third calculation module is used to obtain the corresponding line voltage amplitude based on the instantaneous values ​​of each reconstructed line voltage;

[0044] The judgment module is used to determine whether the current state is a high voltage ride-through state or a low voltage ride-through state based on the line voltage amplitude.

[0045] To address the aforementioned technical problems, this application also provides a detection device for high-altitude and low-altitude crossing conditions, comprising:

[0046] Memory, used to store computer programs;

[0047] The processor is used to execute computer programs to implement the steps of the above-described detection method for high and low crossing conditions.

[0048] To address the aforementioned technical problems, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described detection method for high and low crossing conditions.

[0049] The high-voltage ride-through detection method provided in this application acquires the instantaneous values ​​of the line voltages of the three-phase AC signal; obtains the instantaneous values ​​of the phase voltages of each phase based on the instantaneous values ​​of the line voltages; separates the instantaneous values ​​of the phase voltages of each phase into positive and negative sequences to obtain the reconstructed instantaneous values ​​of the phase voltages of each phase; obtains the reconstructed instantaneous values ​​of the line voltages of each phase based on the reconstructed instantaneous values ​​of the phase voltages; obtains the corresponding line voltage amplitudes based on the reconstructed instantaneous values ​​of the line voltages; and determines whether the current state is a high-voltage ride-through or a low-voltage ride-through state based on the line voltage amplitudes. By reconstructing the instantaneous values ​​of the three-phase voltages using positive and negative sequence voltages, it can adapt to various different power grid operating conditions. By calculating the amplitudes of the three line voltages from the acquired instantaneous values, it can quickly and accurately identify high-voltage ride-through conditions.

[0050] In addition, this application also provides an apparatus and a medium, including the above-mentioned detection method for high and low crossing conditions, with the same effect. Attached Figure Description

[0051] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 A flowchart illustrating a detection method for high and low elevation crossing conditions provided in this application embodiment;

[0053] Figure 2 A schematic diagram illustrating the separation of the positive and negative sequences of instantaneous phase voltage values ​​provided in an embodiment of this application;

[0054] Figure 3 A vector diagram of positive and negative sequence voltages and three-phase voltages provided for embodiments of this application;

[0055] Figure 4 A structural diagram of a detection device for high and low crossing conditions provided in an embodiment of this application;

[0056] Figure 5 This is a structural diagram of another detection device for high and low crossing conditions provided in an embodiment of this application. Detailed Implementation

[0057] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.

[0058] The core of this application is to provide a method, device, and medium for detecting high and low voltage ride-through conditions by rapidly calculating the amplitude of the current voltage.

[0059] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0060] Photovoltaic inverters are a crucial component of photovoltaic (PV) power generation systems. A two-stage PV inverter typically consists of a boost circuit and an inverter circuit. The boost circuit raises the low voltage output from the PV array to a stable high-voltage direct current (DC), which is then converted to alternating current (AC) by the inverter circuit and fed into the grid. Fault ride-through refers to the ability of the inverter to maintain continuous operation without disconnecting from the grid within a specified range and time interval when the AC output voltage exceeds the normal operating range due to a power system fault or disturbance. High-voltage ride-through refers to the ability of the PV inverter to maintain continuous operation without disconnecting from the grid within a certain voltage drop range and time interval when the AC output voltage rises due to a power system fault or disturbance, and to provide dynamic reactive power to support grid recovery. Low-voltage ride-through refers to the ability of the PV inverter to maintain grid connection while providing reactive power support during periods of low voltage, especially when a significant voltage drop occurs during grid connection.

[0061] Existing technologies typically calculate the amplitude of each line voltage using a sliding window root mean square method, or simulate the three-phase voltage for each line voltage using a generalized integrator, and then calculate the d-axis voltage as the amplitude using a phase-locked loop. The first method is simpler, but the update results are slow and cannot quickly detect high-low ride-through conditions; the second method has a faster detection response speed, but it consumes too many software resources and places high demands on the microcontroller unit (MCU).

[0062] This application applies to scenarios requiring testing of high-voltage ride-through or low-voltage ride-through capabilities, such as grid connection acceptance of photovoltaic power plants, grid connection acceptance of wind farms, type testing of photovoltaic inverters, and low-voltage ride-through testing platforms for wind turbine generators.

[0063] To address the aforementioned technical problems, this application provides a detection method for high and low crossing conditions, such as... Figure 1 As shown, it includes:

[0064] S11: Obtain the instantaneous values ​​of the line voltages of the three-phase AC signal;

[0065] S12: Obtain the instantaneous phase voltage value of each phase based on the instantaneous value of each line voltage;

[0066] S13: Separate the instantaneous phase voltage values ​​of each phase into positive and negative sequences to obtain the reconstructed instantaneous phase voltage values ​​of each phase;

[0067] S14: Obtain the instantaneous values ​​of each reconstructed line voltage based on the instantaneous values ​​of the reconstructed phase voltages of each phase;

[0068] S15: Obtain the corresponding line voltage amplitude based on the instantaneous values ​​of each reconstructed line voltage;

[0069] S16: Determine whether the current state is a high-voltage ride-through state or a low-voltage ride-through state by measuring the line voltage amplitude.

[0070] In practical applications, it is generally necessary to determine whether a high-low ride-through condition is required by measuring the amplitude of the three-phase line voltages. This embodiment obtains the instantaneous values ​​of each line voltage of the three-phase AC signal. This embodiment does not limit how the line voltages are obtained; they can be set according to actual needs. Once the instantaneous values ​​of each line voltage are obtained, the corresponding instantaneous phase voltage values ​​for each phase can be derived.

[0071] Three-phase system operation is divided into symmetrical operation and asymmetrical operation. Asymmetrical operation includes single-phase or two-phase short circuits, unbalanced three-phase loads, and single-phase operation. When studying asymmetrical operation conditions, we first assume that the three phases have synchronous and sinusoidal voltages, and that the currents are associated with equal constant impedances or admittances in each phase. We then solve the equations using linear equations and calculate the results using the symmetrical component method. Voltage, current, and impedance voltage are decomposed into three components: positive sequence, negative sequence, and zero sequence. The positive, negative, and zero sequence components are introduced to analyze situations where the system voltage and current are asymmetrical, decomposing the asymmetrical components into symmetrical components (positive and negative sequences) and a zero-sequence component in the same direction. Any three-phase system can be decomposed into these three components (somewhat like the composition and decomposition of forces, but in many cases, the value of one component is zero). For an ideal power system, due to three-phase symmetry, the values ​​of the negative and zero-sequence components are both zero (this is why we often say that only the positive sequence component exists under normal conditions). When a system malfunctions, the three phases become asymmetrical. This allows for the identification of negative-sequence and zero-sequence components with amplitude (sometimes only one type exists). Therefore, by detecting these two components that should not be present, it can be determined that the system is faulty (especially the zero-sequence component in the case of a single-phase ground fault). A three-phase power system consists of three phases A, B, and C, with a phase difference of 120°. Based on the phase sequence of these three phases, positive-sequence, negative-sequence, and zero-sequence components are distinguished.

[0072] Preferably, a phase-locked loop based on a second-order general integrator (SOGI) is used to separate the positive and negative sequences, such as... Figure 2 As shown, the instantaneous values ​​of the three-phase voltages are passed through a dual generalized integrator to obtain the positive and negative sequence voltages on the dq axis. The positive sequence voltage on the q axis is used as the input to the phase-locked loop (PLL) and phase-locking is achieved through a PI controller. After phase-locking is completed, the positive sequence voltage on the q axis is approximately equal to 0. The vector diagram of the positive and negative sequence voltages on the dq axis versus the three-phase voltages is shown below. Figure 3 As shown, the angle between the positive-sequence d-axis and the phase A voltage is wt, and the angle between the negative-sequence d-axis and the phase A voltage is -wt. Therefore, by separating the instantaneous phase voltage values ​​of each phase into positive and negative sequences, the reconstructed instantaneous phase voltage values ​​of each phase are obtained.

[0073] By reconstructing the instantaneous phase voltage values, the instantaneous values ​​of each reconstructed line voltage are obtained, and the corresponding line voltage amplitudes are calculated. Operators can determine whether the current state is a high-voltage ride-through or a low-voltage ride-through state based on the line voltage amplitude. This embodiment does not limit the specific conditions for determining whether the current state is a high-voltage ride-through or a low-voltage ride-through state based on the line voltage amplitude; these conditions can be set according to actual needs.

[0074] The high-voltage ride-through detection method provided in this application involves acquiring the instantaneous values ​​of the line voltages of the three-phase AC signal; obtaining the instantaneous values ​​of the phase voltages of each phase based on the instantaneous values ​​of the line voltages; separating the instantaneous values ​​of the phase voltages of each phase into positive and negative sequences to obtain the reconstructed instantaneous values ​​of the phase voltages of each phase; obtaining the reconstructed instantaneous values ​​of the line voltages of each phase based on the reconstructed instantaneous values ​​of the phase voltages of each phase; obtaining the corresponding line voltage amplitudes based on the reconstructed instantaneous values ​​of the line voltages; and determining whether the current state is a high-voltage ride-through or a low-voltage ride-through state based on the line voltage amplitudes. By reconstructing the instantaneous values ​​of the three-phase voltages using positive and negative sequence voltages, this method can adapt to various different power grid operating conditions. By calculating the amplitudes of the three-phase line voltages from the acquired instantaneous values, it can quickly and accurately identify high-voltage ride-through conditions.

[0075] This embodiment provides a preferred solution for determining whether the current voltage is in a high-voltage ride-through state or a low-voltage ride-through state based on the line voltage amplitude, including:

[0076] Determine whether the minimum value among the three current line voltage amplitudes is less than the rated voltage of the first preset ratio;

[0077] If so, then it is determined that the system is in a low-voltage ride-through state.

[0078] my country's latest grid connection standards specify requirements for the low-voltage ride-through capability of photovoltaic (PV) power plants. These standards stipulate that when a power system fault or disturbance causes a voltage drop at the PV system's grid connection point, the PV grid-connected power generation system should be able to maintain grid connection within a certain voltage drop range and time interval. If necessary, reactive power can be injected into the grid to raise the grid connection point voltage until the grid returns to normal. Typically, the low-voltage ride-through requirement is a reactive current response time ≤30ms and a settling time ≤60ms; therefore, low-voltage ride-through faults must be identified as quickly as possible. This application determines whether the minimum value among the current three line voltage amplitudes is less than a first preset proportion of the rated voltage. For example, if the minimum value among the current three line voltage amplitudes is less than 90% of the rated voltage, it is determined to be in a low-voltage ride-through state. Obviously, the first preset proportion can be set according to actual needs; this embodiment does not limit the specific value.

[0079] In addition, this embodiment provides another judgment condition, which determines whether the current state is a high-voltage ride-through state or a low-voltage ride-through state based on the line voltage amplitude, including:

[0080] Determine whether the current three line voltage amplitudes decrease within a preset time and the difference is greater than the third preset ratio of the rated voltage;

[0081] If so, then it is determined that the system is in a low-voltage ride-through state.

[0082] This embodiment determines whether the difference in the magnitude of the three current line voltages within a preset time period exceeds a third preset proportion of the rated voltage. In other words, it determines whether the magnitude of the three current line voltages decreases significantly within a certain period. For example, if the difference in the magnitude of the three current line voltages within a preset time period exceeds 5% of the rated voltage (i.e., the decrease is greater than 5% of the rated voltage), then it is determined that the voltage is in a low-voltage ride-through state. Obviously, the second preset proportion can be set according to actual needs; this embodiment does not limit the specific value.

[0083] High-voltage ride-through (HVRT) refers to the ability of a photovoltaic (PV) power station to maintain continuous operation without disconnecting from the grid when a power system fault or disturbance causes a sudden voltage surge in the PV power station's grid connection voltage, within a certain voltage surge range and time interval. This embodiment provides a preferred solution that determines whether the current state is HVRT or LVRT based on the line voltage amplitude, including:

[0084] Determine whether the maximum value among the three current line voltage amplitudes is greater than the rated voltage of the second preset ratio;

[0085] If so, then it is determined that the system is in a high-voltage ride-through state.

[0086] This embodiment determines whether the maximum value among the three current line voltage amplitudes is greater than a second preset ratio of the rated voltage. For example, if the maximum value among the three current line voltage amplitudes is greater than 110% of the rated voltage, then it is determined that the voltage is in a high-voltage ride-through state. Obviously, the third preset ratio can be set according to actual needs, and this embodiment does not limit the specific value.

[0087] Based on the above embodiments, this embodiment provides a specific solution for obtaining the instantaneous phase voltage value of each phase based on the instantaneous line voltage value, including:

[0088] The instantaneous phase voltage values ​​of each phase are calculated based on the instantaneous values ​​of each line voltage and the first formula.

[0089] The first formula is:

[0090]

[0091] Among them, U a U is the instantaneous value of the phase voltage of phase A. b U is the instantaneous value of the phase voltage of phase B. c U is the instantaneous value of the phase voltage of phase C. ab U is the instantaneous value of the line voltage between phase A and phase B.bc U is the instantaneous value of the line voltage between phases B and C. ca This represents the instantaneous line voltage between phases A and C.

[0092] When the instantaneous values ​​U of each line voltage are obtained a U b U c Then, the instantaneous phase voltage U of each phase is calculated using the first formula. ab U bc U ca .

[0093] Then, the instantaneous phase voltage values ​​of each phase are separated by positive and negative sequence to obtain the reconstructed instantaneous phase voltage values ​​of each phase, including:

[0094] The instantaneous phase voltage values ​​of each phase are separated into positive and negative sequences to obtain the positive sequence voltage d-axis component, positive sequence voltage q-axis component, negative sequence voltage d-axis component, and negative sequence voltage q-axis component.

[0095] The instantaneous values ​​of the reconstructed phase voltages for each phase are obtained according to the second formula;

[0096] The second formula is:

[0097]

[0098] Among them, U a1 U is the instantaneous value of the reconstructed phase voltage of phase A. b1 U is the instantaneous value of the reconstructed phase voltage of phase B. c1 U is the instantaneous value of the reconstructed phase voltage of phase C. p For positive sequence voltage, U n For the negative sequence voltage, ωt is the angle between the d-axis of the positive sequence voltage and the A-phase voltage, -ωt is the angle between the d-axis of the negative sequence voltage and the A-phase voltage, and θ is the angle between the q-axis of the positive sequence voltage and the d-axis of the negative sequence voltage.

[0099] like Figure 3 As shown, calculate the instantaneous value U of the reconstructed phase voltage for each phase. a1 U b1 U c1 .

[0100] The instantaneous values ​​of each reconstructed line voltage are obtained based on the instantaneous values ​​of the reconstructed phase voltage of each phase, including:

[0101] The instantaneous values ​​of the reconstructed phase voltages of each phase are obtained from the instantaneous values ​​of the reconstructed line voltages and the third formula.

[0102] The third formula is:

[0103]

[0104] Among them, U ab1U is the instantaneous value of the reconfiguration line voltage between phase A and phase B. bc1 U is the instantaneous value of the reconfiguration line voltage between phases B and C. ca1 This represents the instantaneous value of the reconstructed line voltage between phase C and phase A.

[0105] Take U ab1 =U a1 -U b1 For example,

[0106] Therefore, the line voltage amplitude between phase A and phase B is:

[0107] U here abp Line voltage amplitude between phase A and phase B The positive sequence voltage d-axis component The positive-sequence voltage q-axis component is approximately zero. The negative sequence voltage d-axis component This represents the q-axis component of the negative sequence voltage. Similarly, the line voltage amplitude between phases B and C, and between phases C and A, can be obtained. The line voltage amplitude is used to determine whether the current voltage is in a high-voltage ride-through or low-voltage ride-through state. Reconstructing the instantaneous values ​​of the three-phase voltages using positive and negative sequence voltages can adapt to various power grid conditions, reduce computational load, and quickly calculate the amplitudes of the three-phase line voltages, enabling rapid and accurate identification of high- and low-voltage ride-through conditions.

[0108] In the above embodiments, the detection method for high and low elevation crossing conditions has been described in detail. This application also provides embodiments corresponding to the detection device for high and low elevation crossing conditions. It should be noted that this application describes the embodiments of the device part from two perspectives: one is based on the functional module, and the other is based on the hardware.

[0109] From the perspective of functional modules Figure 4 A structural diagram of another detection device for high and low crossing conditions provided in this application embodiment is shown below. Figure 4 As shown, it includes:

[0110] The acquisition module 41 is used to acquire the instantaneous values ​​of the line voltages of the three-phase AC signal;

[0111] The first calculation module 42 is used to obtain the instantaneous phase voltage value of each phase based on the instantaneous value of each line voltage;

[0112] The separation module 43 is used to separate the instantaneous phase voltage values ​​of each phase in positive and negative order to obtain the reconstructed instantaneous phase voltage values ​​of each phase.

[0113] The second calculation module 44 is used to obtain the instantaneous values ​​of each reconstructed line voltage based on the instantaneous values ​​of the reconstructed phase voltage of each phase.

[0114] The third calculation module 45 is used to obtain the corresponding line voltage amplitude based on the instantaneous values ​​of each reconstructed line voltage;

[0115] The judgment module 46 is used to determine whether the current state is a high voltage ride-through state or a low voltage ride-through state based on the line voltage amplitude.

[0116] Specifically, the acquisition module 41 acquires the instantaneous values ​​of the line voltages of the three-phase AC signal; the first calculation module 42 obtains the instantaneous values ​​of the phase voltages of each phase based on the instantaneous values ​​of the line voltages; the separation module 43 separates the instantaneous values ​​of the phase voltages of each phase into positive and negative sequences to obtain the reconstructed instantaneous values ​​of the phase voltages of each phase; the second calculation module 44 obtains the instantaneous values ​​of the reconstructed line voltages of each phase based on the instantaneous values ​​of the reconstructed phase voltages of each phase; the third calculation module 45 obtains the corresponding line voltage amplitude based on the instantaneous values ​​of the reconstructed line voltages; and the judgment module 46 determines whether the current state is a high-voltage ride-through state or a low-voltage ride-through state based on the line voltage amplitude.

[0117] Since the embodiments of the apparatus and the embodiments of the method correspond to each other, please refer to the description of the embodiments of the method for the embodiments of the apparatus, which will not be repeated here.

[0118] Figure 5 A structural diagram of another detection device for high and low crossing conditions provided in this application embodiment is shown below. Figure 5 As shown, the detection device for high and low crossing conditions includes: a memory 50 for storing computer programs;

[0119] The processor 51 is used to execute a computer program to implement the steps of the method for obtaining user operation habit information as described in the above embodiment (detection method for high and low crossing conditions).

[0120] The detection device for high and low crossing conditions provided in this embodiment may include, but is not limited to, smartphones, tablets, laptops, or desktop computers.

[0121] The processor 51 may include one or more processing cores, such as a quad-core processor or an octa-core processor. The processor 51 may be implemented using at least one of the following hardware forms: Digital Signal Processor (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 51 may also include a main processor and a coprocessor. The main processor, also known as the Central Processing Unit (CPU), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 51 may integrate a Graphics Processing Unit (GPU), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor 51 may also include an Artificial Intelligence (AI) processor, which is used to handle computational operations related to machine learning.

[0122] The memory 50 may include one or more computer-readable storage media, which may be non-transitory. The memory 50 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In this embodiment, the memory 50 is used to store at least the following computer program 501, which, after being loaded and executed by the processor 51, is capable of implementing the relevant steps of the high / low crossing condition detection method disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 50 may also include an operating system 502 and data 503, etc., and the storage method may be temporary storage or permanent storage. The operating system 502 may include Windows, Unix, Linux, etc. The data 503 may include, but is not limited to, the data involved in implementing the high / low crossing condition detection method.

[0123] In some embodiments, the detection device for high and low crossing conditions may further include a display screen 52, an input / output interface 53, a communication interface 54, a power supply 55, and a communication bus 56.

[0124] Those skilled in the art will understand that Figure 5 The structure shown does not constitute a limitation on the detection device for high and low crossing conditions and may include more or fewer components than shown.

[0125] The high-voltage ride-through detection device provided in this application includes a memory and a processor. When the processor executes the program stored in the memory, it can implement the following method: a high-voltage ride-through detection method, which involves acquiring the instantaneous values ​​of the line voltages of the three-phase AC signal; obtaining the instantaneous values ​​of the phase voltages of each phase based on the instantaneous values ​​of the line voltages; separating the instantaneous values ​​of the phase voltages of each phase into positive and negative sequences to obtain the reconstructed instantaneous values ​​of the phase voltages of each phase; obtaining the instantaneous values ​​of the reconstructed phase voltages of each phase; obtaining the corresponding instantaneous values ​​of the line voltages based on the instantaneous values ​​of the reconstructed phase voltages; and determining whether the current state is a high-voltage ride-through state or a low-voltage ride-through state based on the line voltage amplitudes. By reconstructing the instantaneous values ​​of the three-phase voltages using positive and negative sequence voltages, it can adapt to various different power grid operating conditions. By calculating the amplitudes of the three-phase line voltages using the acquired instantaneous values, it can quickly and accurately identify high-voltage ride-through states.

[0126] Finally, this application also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps described in the above embodiment of the detection method for high-low crossing conditions.

[0127] It is understood that if the methods in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and executes all or part of the steps of the methods in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0128] The computer-readable storage medium provided in this embodiment stores a computer program. When the processor executes the program, it can implement the following method: a method for detecting high-voltage and low-voltage ride-through conditions, which involves acquiring the instantaneous values ​​of the line voltages of the three-phase AC signals; obtaining the instantaneous values ​​of the phase voltages of each phase based on the instantaneous values ​​of the line voltages; separating the instantaneous values ​​of the phase voltages of each phase into positive and negative sequences to obtain the reconstructed instantaneous values ​​of the phase voltages of each phase; obtaining the instantaneous values ​​of the reconstructed phase voltages of each phase; obtaining the corresponding line voltage amplitudes based on the instantaneous values ​​of the reconstructed line voltages; and determining whether the current state is a high-voltage ride-through or a low-voltage ride-through state based on the line voltage amplitudes. By reconstructing the instantaneous values ​​of the three-phase voltages using positive and negative sequence voltages, it can adapt to various different power grid operating conditions. By calculating the amplitudes of the three-phase line voltages using the acquired instantaneous values, it can quickly and accurately identify high-voltage and low-voltage ride-through conditions.

[0129] The above provides a detailed description of the detection method, apparatus, and medium for high and low crossing conditions provided in this application. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make several improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

[0130] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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 a process, method, article, or apparatus. Without further limitations, 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 said element.

Claims

1. A detection method for high-altitude and low-altitude crossing conditions, characterized in that, include: Obtain the instantaneous values ​​of the line voltages of the three-phase AC signal; The instantaneous value of the phase voltage of each phase is obtained based on the instantaneous value of each line voltage; The instantaneous phase voltage values ​​of each phase are separated by positive and negative sequence to obtain the reconstructed instantaneous phase voltage values ​​of each phase; The instantaneous values ​​of each reconstructed line voltage are obtained based on the instantaneous values ​​of the reconstructed phase voltages of each phase; The corresponding line voltage amplitude is obtained based on the instantaneous values ​​of each reconstructed line voltage; The line voltage amplitude is used to determine whether the current state is a high-voltage ride-through state or a low-voltage ride-through state. The step of determining whether the current voltage is in a high-voltage ride-through state or a low-voltage ride-through state based on the line voltage amplitude includes: Determine whether the minimum value among the three current line voltage amplitudes is less than the rated voltage of the first preset ratio; If so, then it is determined that it is in a low-voltage ride-through state; Determine whether the maximum value among the three current line voltage amplitudes is greater than the rated voltage of the second preset ratio; If so, then it is determined that it is in a high-voltage ride-through state; Determine whether the current three line voltage amplitudes decrease in value within a preset time and the difference is greater than the third preset ratio of the rated voltage; If so, then it is determined that it is in a low-voltage ride-through state; Wherein, obtaining the instantaneous phase voltage value of each phase based on the instantaneous line voltage value includes: The instantaneous phase voltage value of each phase is calculated based on the instantaneous line voltage value and the first formula. The first formula is: in, The instantaneous value of the phase voltage of phase A. The instantaneous value of the phase voltage of phase B. The instantaneous value of the phase voltage of phase C. The instantaneous value of the line voltage between phase A and phase B. The instantaneous value of the line voltage between phase B and phase C. The instantaneous value of the line voltage between phase A and phase C; The step of separating the instantaneous phase voltage values ​​of each phase into positive and negative sequences to obtain the reconstructed instantaneous phase voltage values ​​of each phase includes: The instantaneous phase voltage values ​​of each phase are separated into positive and negative sequences to obtain the positive sequence voltage d-axis component, positive sequence voltage q-axis component, negative sequence voltage d-axis component, and negative sequence voltage q-axis component. The instantaneous values ​​of the reconstructed phase voltages for each phase are obtained according to the second formula; The second formula is: in, The instantaneous value of the reconstructed phase voltage of phase A. The instantaneous value of the reconstructed phase voltage of phase B. The instantaneous value of the reconstructed phase voltage of phase C. The positive sequence voltage. The negative sequence voltage, Let be the angle between the d-axis of the positive sequence voltage and the A-phase voltage. Let be the angle between the d-axis of the negative sequence voltage and the A-phase voltage. The angle between the q-axis of the positive-sequence voltage and the d-axis of the negative-sequence voltage; Wherein, obtaining the instantaneous value of each reconstructed line voltage based on the instantaneous value of the reconstructed phase voltage of each phase includes: The instantaneous values ​​of each reconstructed phase voltage are obtained based on the instantaneous values ​​of each phase reconstructed phase voltage and the third formula; The third formula is: in, The instantaneous value of the reconstructed line voltage between phase A and phase B. The instantaneous value of the reconstructed line voltage between phase B and phase C. The instantaneous value of the reconstructed line voltage between phase C and phase A.

2. A detection device for high-altitude and low-altitude crossing conditions, characterized in that, include: The acquisition module is used to acquire the instantaneous values ​​of the line voltages of the three-phase AC signal; The first calculation module is used to obtain the instantaneous phase voltage value of each phase based on the instantaneous line voltage value of each phase; The separation module is used to separate the instantaneous phase voltage values ​​of each phase in positive and negative order to obtain the reconstructed instantaneous phase voltage values ​​of each phase. The second calculation module is used to obtain the instantaneous values ​​of each reconstructed line voltage based on the instantaneous values ​​of the reconstructed phase voltage of each phase; The third calculation module is used to obtain the corresponding line voltage amplitude based on the instantaneous values ​​of each reconstructed line voltage; The judgment module is used to determine whether the current state is a high voltage ride-through state or a low voltage ride-through state based on the line voltage amplitude. The step of determining whether the current voltage is in a high-voltage ride-through state or a low-voltage ride-through state based on the line voltage amplitude includes: Determine whether the minimum value among the three current line voltage amplitudes is less than the rated voltage of the first preset ratio; If so, then it is determined that it is in a low-voltage ride-through state; Determine whether the maximum value among the three current line voltage amplitudes is greater than the rated voltage of the second preset ratio; If so, then it is determined that it is in a high-voltage ride-through state; Determine whether the current three line voltage amplitudes decrease in value within a preset time and the difference is greater than the third preset ratio of the rated voltage; If so, then it is determined that it is in a low-voltage ride-through state; Wherein, obtaining the instantaneous phase voltage value of each phase based on the instantaneous line voltage value includes: The instantaneous phase voltage value of each phase is calculated based on the instantaneous line voltage value and the first formula. The first formula is: in, The instantaneous value of the phase voltage of phase A. The instantaneous value of the phase voltage of phase B. The instantaneous value of the phase voltage of phase C. The instantaneous value of the line voltage between phase A and phase B. The instantaneous value of the line voltage between phase B and phase C. The instantaneous value of the line voltage between phase A and phase C; The step of separating the instantaneous phase voltage values ​​of each phase into positive and negative sequences to obtain the reconstructed instantaneous phase voltage values ​​of each phase includes: The instantaneous phase voltage values ​​of each phase are separated into positive and negative sequences to obtain the positive sequence voltage d-axis component, positive sequence voltage q-axis component, negative sequence voltage d-axis component, and negative sequence voltage q-axis component. The instantaneous values ​​of the reconstructed phase voltages for each phase are obtained according to the second formula; The second formula is: in, The instantaneous value of the reconstructed phase voltage of phase A. The instantaneous value of the reconstructed phase voltage of phase B. The instantaneous value of the reconstructed phase voltage of phase C. The positive sequence voltage. The negative sequence voltage, Let be the angle between the d-axis of the positive sequence voltage and the A-phase voltage. Let be the angle between the d-axis of the negative sequence voltage and the A-phase voltage. The angle between the q-axis of the positive-sequence voltage and the d-axis of the negative-sequence voltage; Wherein, obtaining the instantaneous value of each reconstructed line voltage based on the instantaneous value of the reconstructed phase voltage of each phase includes: The instantaneous values ​​of each reconstructed phase voltage are obtained based on the instantaneous values ​​of each phase reconstructed phase voltage and the third formula; The third formula is: in, The instantaneous value of the reconstructed line voltage between phase A and phase B. The instantaneous value of the reconstructed line voltage between phase B and phase C. The instantaneous value of the reconstructed line voltage between phase C and phase A.

3. A detection device for high-altitude and low-altitude crossing conditions, characterized in that, include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of the detection method for high and low crossing conditions as described in claim 1.

4. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the detection method for high and low crossing conditions as described in claim 1.

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