Method and device for detecting ct phase sequence, energy storage system and storage medium

Abstract

The application provides a CT phase sequence detection method and device, an energy storage system and a storage medium. The method comprises the following steps: controlling a three-phase inverter to receive commercial power, converting the received commercial power into direct current, storing the direct current in an energy storage battery, and charging power being P; generating a power factor; when the power factor is greater than 0.95 and less than a preset threshold, a corresponding phase line corresponds to a corresponding current transformer phase sequence. The detection method can determine whether the phase sequence of the current transformer in the three-phase inverter corresponds.

Description

Technical Field

[0001] This invention relates to the field of new energy technology, and in particular to a method, device, energy storage system and storage medium for detecting CT phase sequence. Background Technology

[0002] With the continuous development of the new energy market, the installation volume of three-phase inverters for energy storage is also increasing. Users and manufacturers alike hope for simpler operation during installation, and the ability to monitor and correct problems in real time. However, when installing current transformers (CTs), the phase sequence and installation direction are very easy to confuse.

[0003] Specifically, in a three-phase electrical system, there are three phase lines: L1, L2, and L3 (also called A, B, and C). Each phase line requires its own current transformer (CT) to measure the current in that phase. The correct phase sequence means that the CT for L1 should be installed on the L1 phase line; the CT for L2 should be installed on the L2 phase line, and so on. For example, installing the CT for L1 on the L2 phase line is considered an incorrect phase sequence connection. The CT is essentially a current sensor with fixed current inflow and outflow directions, usually marked with P1 / P2, S1 / S2, or an arrow. When correctly installed, current should flow in from the P1 side and out from the P2 side. If installed incorrectly, current will flow in from P2 and out from P1, which is called "reverse installation direction" and will cause the current polarity to completely reverse.

[0004] These two points are very easy to confuse: 1. The objective chaos of the site environment: the colors / markings of the three-phase cables themselves may be unclear, or the labels may be missing, making it difficult to quickly distinguish which cable is L1 / L2 / L3. Multiple CTs look exactly the same, making it easy to mix them up or install them in the wrong place during installation. Dense cable arrangement, limited installation space for CTs, obstructed view, and easy to misread the direction indicators. 2. Subjective errors in human operation: installation personnel are often fatigued or rushing to meet deadlines, making them prone to carelessness when checking phase sequence and direction. Inconsistencies between the drawings and the on-site wiring, or unclear markings on the drawings, lead to misunderstandings. Novices are unfamiliar with the polarity markings (P1 / P2) of the CTs and may not even notice if they install them backwards.

[0005] Confusion can have the following consequences: 1. Incorrect phase sequence connection will cause complete confusion in the inverter / meter's power calculation, resulting in abnormal three-phase power distribution. This can lead to inaccurate metering or, in severe cases, inverter errors, shutdowns, and grid connection failures. 2. Reversed direction connection will reverse the polarity of the measured current. During charging, the power factor will become negative, causing the inverter to misinterpret it as "discharging," triggering the protection mechanism and preventing the equipment from functioning properly.

[0006] In summary, determining whether the phase sequence of the current transformers in a three-phase inverter is correct has become an urgent problem to be solved. Summary of the Invention

[0007] The purpose of this invention is to provide a method, device, energy storage system and storage medium for detecting CT phase sequence.

[0008] To achieve one of the aforementioned objectives, an embodiment of the present invention provides a method for detecting the phase sequence of a current transformer (CT) in an energy storage system. The energy storage system includes a three-phase inverter and an energy storage battery. A current transformer is installed on each of the L1, L2, and L3 phase lines of the three-phase inverter. The method includes the following steps: controlling the three-phase inverter to receive mains power, converting the received mains power into direct current (DC), storing the DC power in the energy storage battery with a charging power of P, and continuing for a preset time; and acquiring the instantaneous voltage value of the L1 phase line during the charging process. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L1 ; Obtain the instantaneous voltage value of phase L2 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L2 ; Obtain the instantaneous voltage value of phase L3 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L3. ; Obtain the instantaneous current value output by the first current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the first current transformer. ; Obtain the instantaneous current value output by the second current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the second current transformer. ; Obtain the instantaneous current value output by the third current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the third current transformer. ;in, T represents one power frequency cycle; the first, second, and third current transformers are three different current transformers; power factor Among them, active power Apparent power Where k and m are both natural numbers, and the values ​​of k and m are 1, 2, and 3 respectively; when >0.95 and When the preset threshold is reached, The corresponding phase line and The corresponding current transformer phase sequence is correct. Corresponding to phase line L1, Corresponding to phase line L2, Corresponding to phase L3, Corresponding to the first current transformer, Corresponding to the second current transformer, For the third current transformer, the preset threshold is >0.

[0009] As a further improvement to one embodiment of the present invention, the method further includes the following step: when When <0, The installation direction of the corresponding current transformer is reversed.

[0010] As a further improvement to one embodiment of the present invention, the method based on instantaneous voltage values... Generate the effective voltage value corresponding to phase line L1 Specifically, it includes: The voltage instantaneous value is mentioned. Generate the effective voltage value corresponding to phase line L2 Specifically, it includes: The voltage instantaneous value is mentioned. Generate the effective voltage value corresponding to phase line L3. Specifically, it includes: .

[0011] As a further improvement to one embodiment of the present invention, the method based on instantaneous current value... Generate the effective value of the current output from the first current transformer. Specifically, it includes: The statement based on instantaneous current value Generate the effective value of the current output from the second current transformer. Specifically, it includes: The statement based on instantaneous current value Generate the effective value of the current output from the third current transformer. Specifically, it includes: .

[0012] This invention also provides a device for detecting the phase sequence of a current transformer (CT) in an energy storage system. The energy storage system includes a three-phase inverter and an energy storage battery. A current transformer is installed on each of the L1, L2, and L3 phase lines of the three-phase inverter. The device includes the following modules: a charging module, used to control the three-phase inverter to receive mains power, convert the received mains power into direct current (DC), store the DC power in the energy storage battery with a charging power of P, and continue for a preset time; and a preprocessing module, used to acquire the instantaneous voltage value of the L1 phase line during the charging process. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L1 ; Obtain the instantaneous voltage value of phase L2 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L2 ; Obtain the instantaneous voltage value of phase L3 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L3. ; Obtain the instantaneous current value output by the first current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the first current transformer. ; Obtain the instantaneous current value output by the second current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the second current transformer. ; Obtain the instantaneous current value output by the third current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the third current transformer. ;in, T represents one power frequency cycle; the first, second, and third current transformers are three different current transformers; power factor Among them, active power Apparent power Where k and m are both natural numbers, and the values ​​of k and m are 1, 2, and 3 respectively; the first detection module is used when >0.95 and When the preset threshold is reached, The corresponding phase line and The corresponding current transformer phase sequence is correct. Corresponding to phase line L1, Corresponding to phase line L2, Corresponding to phase L3, Corresponding to the first current transformer, Corresponding to the second current transformer, For the third current transformer, the preset threshold is >0.

[0013] As a further improvement of one embodiment of the present invention, it further includes the following module: a second detection module, used when... When <0, The installation direction of the corresponding current transformer is reversed.

[0014] As a further improvement to one embodiment of the present invention, the preprocessing module is further configured to: , , .

[0015] As a further improvement to one embodiment of the present invention, the preprocessing module is further configured to: , , .

[0016] This invention also provides an energy storage system, including: a memory for storing a computer program; and a processor communicatively connected to the memory, wherein the processor is configured to implement the above-described detection method when executing the computer program.

[0017] This invention also provides a storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the detection method described above.

[0018] Compared with the prior art, the technical advantages of the present invention are as follows: The embodiments of the present invention provide a method for detecting CT phase sequence, including a device, an energy storage system, and a storage medium, comprising the following steps: controlling a three-phase inverter to receive mains power, converting the received mains power into direct current, storing the direct current in an energy storage battery with a charging power of P; generating a power factor. ;when >0.95 and When the preset threshold is reached, The corresponding phase line and The phase sequence of the corresponding current transformers is correct. This detection method can determine whether the phase sequence of the current transformers in a three-phase inverter is correct. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the method for detecting the CT phase sequence of an energy storage system according to an embodiment of the present invention. Detailed Implementation

[0020] The following description and accompanying drawings fully illustrate specific embodiments described herein to enable those skilled in the art to practice them. Some embodiments may include or substitute parts and features of other embodiments. The scope of the embodiments herein encompasses the entire scope of the claims and all available equivalents thereof. Throughout this document, the terms “first,” “second,” etc., are used only to distinguish one element from another without requiring or implying any actual relationship or order between the elements. Indeed, a first element can also be referred to as a second element, and vice versa. Furthermore, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a structure, apparatus, or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a structure, apparatus, or device. Without further limitation, an element defined by the phrase “comprising one…” does not exclude the presence of other identical elements in the structure, apparatus, or device that includes said element. The various embodiments described herein are presented 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.

[0021] Embodiment 1 of the present invention provides a method for detecting the phase sequence of a current transformer (CT) in an energy storage system. The energy storage system includes a three-phase inverter and an energy storage battery. A current transformer is installed on each of the L1, L2, and L3 phase lines of the three-phase inverter. Figure 1 As shown, it includes the following steps: Step 101: Control the three-phase inverter to receive mains power, convert the received mains power into DC power, store the DC power in the energy storage battery with a charging power of P, and continue for a preset time; here, mains power refers to the AC power commonly used in homes and factories, that is, the civil / industrial power directly supplied by the power grid. The domestic standard is AC power with a voltage of 220V and a frequency of 50Hz.

[0022] Step 102: Obtain the instantaneous voltage value of phase L1 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L1 ; Obtain the instantaneous voltage value of phase L2 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L2 ; Obtain the instantaneous voltage value of phase L3 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L3. ; Obtain the instantaneous current value output by the first current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the first current transformer. ; Obtain the instantaneous current value output by the second current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the second current transformer. ; Obtain the instantaneous current value output by the third current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the third current transformer. ;in, T represents one power frequency cycle; the first, second, and third current transformers are three different current transformers; power factor Among them, active power Apparent power Where k and m are both natural numbers, and the values ​​of k and m are 1, 2 and 3 respectively; here, a voltage meter is installed on each phase line to measure the instantaneous voltage value.

[0023] Step 103: When >0.95 and When the preset threshold is reached, The corresponding phase line and The corresponding current transformer phase sequence is correct. Corresponding to phase line L1, Corresponding to phase line L2, Corresponding to phase L3, Corresponding to the first current transformer, Corresponding to the second current transformer, For the third current transformer, the preset threshold is >0.

[0024] Apparent power is the product of the effective values ​​of voltage and current in an AC circuit, reflecting the circuit's "capacity," and is measured in VA (volt-ampere). Single-phase circuit: .

[0025] Apparent power calculation for a three-phase four-wire inverter (with neutral line), single-phase apparent power (each phase calculated independently). In a star-connected (Y-connected) three-phase system with a neutral line, the voltage and current of each phase are sampled independently; effective phase voltage value: , , (These represent the voltages of L1, L2, and L3 relative to the neutral line N, respectively). Effective value of phase current: , , (The line currents of L1, L2, and L3 are equal to the phase currents). The apparent power of each phase is: , , The total apparent power of the three phases is the direct sum of the apparent power of the three phases: .

[0026] For the apparent power calculation of a three-phase three-wire inverter (without a neutral line), for a three-phase system without a neutral line (delta connection, or star connection without a neutral line), we usually sample the line voltage and line current. There are two calculation methods: 1. Line voltage / line current method (most commonly used): When the three phases are balanced (equal amplitudes of three-phase voltage and current, phase difference of 120°), the formula for total apparent power is: , This is the effective value of the line voltage (e.g., 380V). This is the effective value of the line current (such as the current per phase).

[0027] 2. Line voltage-line current pairwise product method (three-phase unbalanced scenario): When the three phases are unbalanced, the above balance formula is no longer applicable. It is necessary to use the pairwise combination of line voltage and line current for calculation, corresponding to the "two-watt method" principle of three-phase power meters: , , , These are the three-phase line voltages (the voltages between L1-L2, L2-L3, and L3-L1). , , These are the three-phase line currents.

[0028] The steps to calculate "single-phase apparent power" are as follows: Step 1: Voltage sampling. Use a meter to sample the instantaneous voltage values ​​of phases L1, L2, and L3 in real time. and , T is one power frequency cycle, such as 20ms / 50Hz. Calculate the effective value: .

[0029] Step 2: Current sampling. The first, second, and third current transformers output the instantaneous values ​​of the three-phase currents, respectively. , , Similarly, the effective values ​​were calculated: .

[0030] Step 3: Single-phase apparent power calculation. For each pair of "phase voltage-current" combinations (including combinations with incorrect phase sequence), calculate the corresponding apparent power: k is the phase voltage number. When k=1, it corresponds to phase line L1; when k=2, it corresponds to phase line L2; when k=3, it corresponds to phase line L3; when m=1, it corresponds to the first current transformer; when m=2, it corresponds to the second current transformer; when m=3, it corresponds to the third current transformer.

[0031] Step 4, Power Factor Calculation (Key Judgment): Use the previously calculated active power... Divide by apparent power The power factor is obtained as follows: When k=m (phase sequence is correct) and CT direction is correct, >0.95, and ,Right now <Preset threshold.

[0032] Active power is calculated by summing the products of sampled current and voltage over a period of 20ms. ,in, It is the phase difference between voltage and current. This refers to the power factor (PF). In scenarios where the inverter is charging a battery, the inverter actively controls the current and voltage to be almost in phase, meaning... ,at this time: , The charging power per phase is .

[0033] When the phase sequence is incorrect, the power factor (PF) will drop significantly, and the phase difference between phases L1 / L2 / L3 of the three-phase power supply will be significant. .when At that time, voltage and current From different phases, phase difference ,at this time: Therefore, the calculated active power It will be much smaller Even negative values, corresponding to It will also be much less than 0.95. For example: multiplying the voltage of L1 by the current of L2, the phase difference... ,at this time Power factor It does not meet the condition of >0.95 at all.

[0034] If you only look at There is a possibility of misjudgment: when the three phases are unbalanced, the power of other phases may be close to 1000W; noise or sampling errors may cause the power of the incorrect combination to approach the target value. If only looking at... There is also a possibility of misjudgment: when the load is purely resistive, the voltage and current of different phases may accidentally match in phase. When the apparent power is very small, even if the phase difference is large, PF may be misjudged as close to 1 due to calculation errors. The scheme uses two conditions simultaneously: Ensure that the phase difference between voltage and current is small enough, and that they are indeed in phase; Ensuring the power amplitude matches expectations and eliminating interference from noise, imbalance, and other factors are two complementary conditions that significantly reduce the probability of misjudgment, making it a very reliable design in engineering.

[0035] This embodiment also includes the following steps: when When <0, The installation direction of the corresponding current transformer is reversed.

[0036] Here, when the current transformer is connected in reverse, the CT direction will be reversed, which will cause the measured current phase to reverse. At this point, the current i(t) becomes -i(t), and the phase difference... Become ,at this time: Therefore, the calculated active power It will be a negative value, corresponding to It does not meet the conditions either.

[0037] In this embodiment, the voltage instantaneous value is used as the basis. Generate the effective voltage value corresponding to phase line L1 Specifically, it includes: The voltage instantaneous value is mentioned. Generate the effective voltage value corresponding to phase line L2 Specifically, it includes: The voltage instantaneous value is mentioned. Generate the effective voltage value corresponding to phase line L3. Specifically, it includes: .

[0038] In this embodiment, the method based on instantaneous current value Generate the effective value of the current output from the first current transformer. Specifically, it includes: The statement based on instantaneous current value Generate the effective value of the current output from the second current transformer. Specifically, it includes: The statement based on instantaneous current value Generate the effective value of the current output from the third current transformer. Specifically, it includes: .

[0039] Embodiment 2 of the present invention provides a detection device for the phase sequence of a current transformer (CT) in an energy storage system. The energy storage system includes a three-phase inverter and an energy storage battery. A current transformer is installed on each of the L1, L2, and L3 phase lines of the three-phase inverter. The device includes the following modules: a charging module, used to control the three-phase inverter to receive mains power, convert the received mains power into direct current (DC), store the DC power in the energy storage battery with a charging power of P, and continue for a preset time; and a preprocessing module, used to acquire the instantaneous voltage value of the L1 phase line during the charging process. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L1 ; Obtain the instantaneous voltage value of phase L2 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L2 ; Obtain the instantaneous voltage value of phase L3 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L3. ; Obtain the instantaneous current value output by the first current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the first current transformer. ; Obtain the instantaneous current value output by the second current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the second current transformer. ; Obtain the instantaneous current value output by the third current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the third current transformer. ;in, T represents one power frequency cycle; the first, second, and third current transformers are three different current transformers; power factor Among them, active power Apparent power Where k and m are both natural numbers, and the values ​​of k and m are 1, 2, and 3 respectively; the first detection module is used when >0.95 and When the preset threshold is reached, The corresponding phase line and The corresponding current transformer phase sequence is correct. Corresponding to phase line L1, Corresponding to phase line L2, Corresponding to phase L3, Corresponding to the first current transformer, Corresponding to the second current transformer, For the third current transformer, the preset threshold is >0.

[0040] This embodiment also includes the following module: a second detection module, used when... When <0, The installation direction of the corresponding current transformer is reversed.

[0041] In this embodiment, the preprocessing module is further used for: , , .

[0042] In this embodiment, the preprocessing module is further used for: , , .

[0043] Embodiment 3 of the present invention provides an energy storage system, including: a memory for storing a computer program; and a processor communicatively connected to the memory, wherein the processor is configured to implement the detection method in Embodiment 1 when executing the computer program.

[0044] In practice, this energy storage system is capable of performing the following operations: Step 1: System Installation and Cloud Platform Connection. First, complete the hardware installation and electrical connection of the energy storage inverter, battery, and current transformer (CT). The energy storage inverter is equipped with a network communication module, supporting two access methods: wireless connection via a Wi-Fi stick; and access to the cloud platform via a network cable and Ethernet interface, using the W5500 chip and TCP / IP protocol. After the device is connected to the home network, the three-phase grid voltage, current, power, and other data collected by the CT are uploaded to the cloud platform in real time for visualization and monitoring.

[0045] Step Two: Transmission and Preprocessing of Control Commands. The cloud platform sends phase sequence detection control commands to the WIFI stick or Ethernet communication module via TCP / IP protocol. The communication module then transmits the commands to the Energy Management System (EMS) built into the energy storage inverter. After receiving the commands, the EMS first confirms that the current metering device is a CT (Cyclic Transmission Device), and then generates a standard CAN (Controller Area Network) protocol command with a length of 8 bytes (the command content can be set to 00 01 00 00 00 00 00 00), and sends it to the meter module built into the inverter, notifying it to enter the detection method process in Example One. At the same time, the EMS determines that the device is in grid-connected status and the battery is normally connected, and then enters the phase sequence adaptive mode to set the inverter's battery charging power parameters.

[0046] Step 3: Execution of the phase sequence adaptive correction function. The inverter draws power from the grid and charges the battery according to the charging power command issued by the EMS. The meter module performs parameter correction based on the real-time collected three-phase grid data. This process lasts approximately 3 minutes. During the correction process, the meter module continuously feeds back the detection status to the EMS via the CAN protocol (e.g., sending the command 01 0000 00 00 00 00 00, where the leftmost byte 01 indicates that the meter module is currently in the phase sequence detection process). After the phase sequence detection is completed, the meter module sends the detection status and result to the EMS via the CAN protocol. The command content can be set to 0201 00 00 00 00 00 00, where the first byte 02 indicates the end of the detection process, and the second byte 01 indicates the success of the detection. After receiving the detection end information, the EMS exits the phase sequence adaptive mode and issues a control command to stop the inverter from charging the battery. Finally, the EMS uploads the phase sequence detection result to the cloud platform; if the detection fails, the user can trigger the phase sequence detection process again through the cloud platform.

[0047] Embodiment 3 of the present invention provides a storage medium on which a computer program is stored. When the computer program is executed by a processor, it implements the steps of the detection method in Embodiment 1.

[0048] It should be noted that although the steps are described in a specific order above, it does not mean that the steps must be executed in the above specific order. In fact, some of these steps can be executed concurrently, or even in a different order, as long as the required function can be achieved.

[0049] This invention can be a system, method, and / or computer program product. A computer program product may include a readable storage medium having computer-readable program instructions loaded thereon for causing a processor to implement various aspects of the invention.

[0050] A readable storage medium can be a tangible device that holds and stores instructions for use by an instruction execution device. Readable storage media can include, for example, but not limited to, electrical storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination thereof. More specific examples (a non-exhaustive list) of readable storage media include: portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), static random access memory (SRAM), portable compact disc read-only memory (CD-ROM), digital multifunction disc (DVD), memory sticks, floppy disks, mechanical encoding devices, such as punch cards or recessed protrusions storing instructions thereon, and any suitable combination thereof.

[0051] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for detecting the phase sequence of a CT (Continuous Transmission) in an energy storage system, the energy storage system comprising: A three-phase inverter and an energy storage battery, wherein a current transformer is installed on each of the L1, L2, and L3 phase lines of the three-phase inverter; characterized by comprising the following steps: The three-phase inverter is controlled to receive mains power, convert the received mains power into DC power, store the DC power in the energy storage battery with a charging power of P, and continue for a preset time. Obtain the instantaneous voltage value of phase L1 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L1 ; Obtain the instantaneous voltage value of phase L2 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L2 ; Obtain the instantaneous voltage value of phase L3 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L3. ; Obtain the instantaneous current value output by the first current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the first current transformer. ; Obtain the instantaneous current value output by the second current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the second current transformer. ; Obtain the instantaneous current value output by the third current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the third current transformer. ;in, T represents one power frequency cycle; the first, second, and third current transformers are three different current transformers; power factor Among them, active power Apparent power Where k and m are both natural numbers, and the values ​​of k and m are 1, 2 and 3 respectively; when >0.95 and When the preset threshold is reached, The corresponding phase line and The corresponding current transformer phase sequence is correct. Corresponding to phase line L1, Corresponding to phase line L2, Corresponding to phase L3, Corresponding to the first current transformer, Corresponding to the second current transformer, For the third current transformer, the preset threshold is >

0.

2. The detection method according to claim 1, characterized in that, It also includes the following steps: when When <0, The installation direction of the corresponding current transformer is reversed.

3. The detection method according to claim 1, characterized in that, The voltage instantaneous value Generate the effective voltage value corresponding to phase line L1 Specifically, it includes: ; The voltage instantaneous value Generate the effective voltage value corresponding to phase line L2 Specifically, it includes: ; The voltage instantaneous value Generate the effective voltage value corresponding to phase line L3. Specifically, it includes: .

4. The detection method according to claim 1, characterized in that, The basis is the instantaneous value of the current. Generate the effective value of the current output from the first current transformer. Specifically, it includes: ; The basis is the instantaneous value of the current. Generate the effective value of the current output from the second current transformer. Specifically, it includes: ; The basis is the instantaneous value of the current. Generate the effective value of the current output from the third current transformer. Specifically, it includes: .

5. A device for detecting the phase sequence of a CT in an energy storage system, the energy storage system comprising: A three-phase inverter and an energy storage battery, wherein a current transformer is installed on each of the L1, L2, and L3 phase lines of the three-phase inverter; characterized in that it includes the following modules: The charging module is used to control the three-phase inverter to receive mains power, convert the received mains power into DC power, store the DC power in the energy storage battery with a charging power of P, and continue for a preset time. The preprocessing module is used to obtain the instantaneous voltage value of phase L1 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L1 ; Obtain the instantaneous voltage value of phase L2 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L2 ; Obtain the instantaneous voltage value of phase L3 during charging. Based on instantaneous voltage value Generate the effective voltage value corresponding to phase line L3. ; Obtain the instantaneous current value output by the first current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the first current transformer. ; Obtain the instantaneous current value output by the second current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the second current transformer. ; Obtain the instantaneous current value output by the third current transformer during the charging process. Based on instantaneous current value Generate the effective value of the current output from the third current transformer. ;in, T represents one power frequency cycle; the first, second, and third current transformers are three different current transformers; power factor Among them, active power Apparent power Where k and m are both natural numbers, and the values ​​of k and m are 1, 2 and 3 respectively; The first detection module is used when... >0.95 and When the preset threshold is reached, The corresponding phase line and The corresponding current transformer phase sequence is correct. Corresponding to phase line L1, Corresponding to phase line L2, Corresponding to phase L3, Corresponding to the first current transformer, Corresponding to the second current transformer, For the third current transformer, the preset threshold is >

0.

6. The detection device according to claim 5, characterized in that, It also includes the following modules: The second detection module is used when... When <0, The installation direction of the corresponding current transformer is reversed.

7. The detection device according to claim 5, characterized in that, The preprocessing module is also used for: , , .

8. The detection device according to claim 5, characterized in that, The preprocessing module is also used for: , , .

9. An energy storage system, characterized in that, include: Memory, used to store computer programs; A processor, communicatively connected to the memory, is configured to implement the detection method as described in any one of claims 1 to 4 when executing the computer program.

10. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the detection method according to any one of claims 1 to 4.

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