Over-current protection method and system of energy storage valve, computer equipment and storage medium

Abstract

The invention relates to an overcurrent protection method and system for an energy storage valve, computer equipment, a storage medium and a computer program product. The method comprises the following steps: acquiring real-time operation parameters of a bridge arm of the converter; wherein the real-time operation parameters at least comprise a real-time bridge arm current value and the duration of the real-time bridge arm current value; if the real-time operation parameter of the bridge arm of the converter meets the bridge arm permanent locking condition of permanent overcurrent protection, generating a permanent overcurrent protection signal, and sending the permanent overcurrent protection signal to a logic judgment unit for judgment; and if the judgment result is that the bridge arm of the converter is permanently overcurrent, carrying out bridge arm permanent locking on the bridge arm of the converter. By adopting the method, the reliability of overcurrent protection can be improved.

Description

Overcurrent protection method, system, computer equipment and storage medium for energy storage valve Technical Field

[0001] The present application relates to the field of power system energy storage technology, and in particular to an overcurrent protection method, system, computer equipment, storage medium and computer program product for an energy storage valve. Background Art

[0002] In current energy storage systems, PCS (energy storage converter) and energy storage batteries are independent of each other. Multiple PCSs connected in parallel are prone to oscillation, and the two-level / three-level PCS has low power conversion efficiency. The series and parallel connection of a large number of batteries requires the BMS (Battery Management System) to have strong battery management capabilities. There are also problems such as three-phase imbalance in the distribution network and line overload / underload.

[0003] With the development of new energy technologies, new energy storage systems have emerged that can achieve flexible regulation of the output power of the energy storage system and optimize the management capabilities of the battery pack. At the same time, they can eliminate grid-connected harmonics, reduce costs, lower the DC voltage that the battery withstands and the BMS's requirements for the battery tube control capabilities, resulting in lower system network losses and higher operational reliability.

[0004] The new energy storage valve control system is the core control device of the new energy storage system. However, the protection method of the new energy storage system is to protect it through the locking and tripping of temporary overcurrent protection. The protection method is single and the reliability is low.

[0005] Summary of the Invention

[0006] In view of the above problems, the present application provides an overcurrent protection method, system, computer equipment, storage medium and computer program product for an energy storage valve, which can solve the problems of temporary overcurrent protection locking and tripping for overcurrent protection, single overcurrent protection and low reliability.

[0007] In a first aspect, the present application provides an overcurrent protection method for an energy storage valve. The method comprises:

[0008] Acquire real-time operating parameters of the bridge arm of the converter; the real-time operating parameters at least include a real-time bridge arm current value and a duration of the real-time bridge arm current value;

[0009] If the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent blocking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment;

[0010] If the judgment result is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked.

[0011] In the above embodiment, when the bridge arm of the converter is released from temporary locking, the operating parameters of the converter are detected in real time to perform overcurrent protection. When it is detected in real time that the real-time bridge arm current value and the duration of the converter meet the permanent arm locking condition of the permanent overcurrent protection, the bridge arm of the converter is permanently locked by sending the permanent overcurrent protection signal to the logic judgment unit. When the permanent arm locking condition of the permanent overcurrent protection is met, the converter is locked and the corresponding bridge arm of the converter is protected from overcurrent, instead of directly locking the entire converter and tripping the line switch. The converter overcurrent protection is segmented, thereby improving the reliability of the overcurrent protection.

[0012] In one embodiment, before obtaining the operating parameters of the bridge arm of the converter, the method further includes:

[0013] Acquiring a first operating parameter of a bridge arm of the converter;

[0014] If the first operating parameter meets the temporary overcurrent protection start condition, a temporary overcurrent protection signal is generated;

[0015] temporarily blocking the bridge arm of the converter based on the temporary overcurrent protection signal, and recording the number of temporary blocking times of the bridge arm of the converter;

[0016] Obtaining a second operating parameter of a bridge arm of the converter;

[0017] If the second operating parameter satisfies the overcurrent protection release condition, generating an overcurrent protection release signal;

[0018] The bridge arm of the converter is unlocked based on the overcurrent protection release signal.

[0019] In the above embodiment, when the bridge arm of the converter is temporarily overcurrented, the converter is locked. By further determining whether the overcurrent protection is released, the temporary lock is unlocked to avoid the temporary lock directly tripping the line switch and causing the entire station to stop operating.

[0020] In one embodiment, the first operating parameter includes a first bridge arm current value and a duration of the first bridge arm current value, and if the first operating parameter satisfies a temporary overcurrent protection start condition, generating a temporary overcurrent protection signal includes:

[0021] If at least two valve protection units detect that the corresponding first bridge arm current value is greater than the first set current of the temporary overcurrent protection, and the overcurrent duration of the first bridge arm current value is greater than the first set duration of the temporary overcurrent protection, at least two candidate temporary overcurrent protection signals are generated;

[0022] At least two of the candidate temporary over-current protection signals are sent to a logic judgment unit, and the logic judgment unit makes a judgment based on the at least two temporary over-current protection signals to generate a temporary over-current protection signal.

[0023] In the above embodiment, when the converter bridge arm is in a temporary overcurrent state, at least two valve protection units are used for detection to generate at least two candidate temporary overcurrent protection signals, and the logic judgment unit judges the at least two candidate temporary overcurrent protection signals to generate a temporary overcurrent protection signal, thereby improving the reliability of the temporary overcurrent protection.

[0024] In one embodiment, temporarily blocking the bridge arm of the converter based on the temporary overcurrent protection signal includes:

[0025] The temporary overcurrent protection signal is sent to a valve control unit, and the bridge arm of the converter is temporarily blocked by the valve control unit.

[0026] In the above embodiment, temporary blocking is directly performed on the valve control unit side according to the temporary overcurrent protection signal sent upward, thereby improving data processing performance and reliability.

[0027] In one embodiment, the first set current has a value range of 1.2 to 2.0 rated current values, and the first set duration has a value range of 0 to 500 us.

[0028] In one embodiment, the first set current is greater than the second set current, the first set time is less than the second set time, the second set current has a value range of 0 to 1.0 rated current value, and the second set time has a value range of 0us to 3000us.

[0029] In the above embodiment, by considering the temporary overcurrent of the energy storage valve control system and the autonomous recovery of the temporary overcurrent, the set current and duration of the temporary overcurrent lockout, as well as the set current and duration of the unlocking, are set, thereby ensuring the stability and safety of the energy storage valve control system.

[0030] In one embodiment, the real-time operating parameters further include a temporary blocking number. If the real-time operating parameters of the bridge arm of the converter meet the permanent blocking condition of the bridge arm for permanent overcurrent protection, a permanent overcurrent protection signal is generated, including:

[0031] If it is detected that the number of temporary blocking times is greater than a set threshold, a permanent overcurrent protection signal is generated.

[0032] In the above embodiment, when a temporary lockout is followed by unlocking, a permanent overcurrent protection signal is generated by counting the number of temporary lockouts. This provides segmented overcurrent protection for the converter bridge arms, increasing the number of overcurrent protection options and improving the reliability of overcurrent protection.

[0033] In one embodiment, the real-time operating parameters further include a temporary blocking number. If the real-time operating parameters of the bridge arm of the converter meet the permanent blocking condition of the bridge arm for permanent overcurrent protection, a permanent overcurrent protection signal is generated, including:

[0034] When the number of temporary blocking times is less than a set threshold, if the real-time bridge arm current value and the duration meet the bridge arm permanent blocking condition of permanent overcurrent protection, a permanent overcurrent protection signal is generated.

[0035] In the above embodiment, when temporarily locked and then unlocked, after the time limit and the set value are extended and the requirements of the set value and the time limit are met, a permanent overcurrent protection signal of the single bridge arm is generated, and then the bridge arm converter valve plays a protective role, the overcurrent protection method is increased, and the reliability of the overcurrent protection is improved.

[0036] In one embodiment, if the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent blocking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment, including:

[0037] If the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, a permanent overcurrent protection signal is generated and sent to the logic judgment unit for judgment.

[0038] In the above embodiment, when temporarily locked and then unlocked, after the time limit and the set value are extended and the requirements of the set value and the time limit are met, the converter is controlled by a permanent overcurrent protection signal to perform single-arm permanent valve locking, and then the bridge arm converter valve plays a protective role, increasing the overcurrent protection method and improving the reliability of the overcurrent protection.

[0039] In one embodiment, if the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment, including:

[0040] If at least two valve protection units detect that the corresponding real-time bridge arm current value is greater than the third set current of permanent overcurrent protection and the duration is greater than the third set duration of permanent overcurrent protection, at least two candidate permanent overcurrent protection signals are generated;

[0041] Sending at least two of the candidate permanent over-current protection signals to a logic judgment unit, and performing a judgment by the logic judgment unit based on the at least two candidate permanent over-current protection signals;

[0042] If at least one of the candidate permanent overcurrent protection signals indicates that the bridge arm of the converter is permanently overcurrent, it is determined that the bridge arm of the converter is permanently overcurrent.

[0043] In the above embodiment, when temporarily locked and then unlocked, the time limit and the set value are extended, and after the valve protection unit is further tested to meet the requirements of the set value and the time limit, the candidate permanent overcurrent protection signals of multiple valve protection units are judged by the logic judgment unit to generate a permanent overcurrent protection signal to ensure the reliability of the permanent overcurrent protection signal.

[0044] In one embodiment, if the bridge arm of the converter is permanently overcurrent, permanently locking the bridge arm of the converter includes:

[0045] The permanent overcurrent protection signal is sent to a valve control unit, and the bridge arm of the converter is permanently locked by the valve control unit.

[0046] In the above embodiment, temporary blocking is directly performed on the valve control unit side according to the sent permanent overcurrent protection signal, thereby improving data processing performance and reliability.

[0047] In one embodiment, the third set current value ranges from 1.5 to 2.0 rated current values, and the third set time value ranges from 0 us to 1000 us. By setting the set current value and time limit of permanent overcurrent protection, permanent overcurrent protection is performed.

[0048] In one embodiment, the method further comprises:

[0049] If it is detected that all bridge arms of the converter are not in the state of permanent arm blocking, obtaining a third operating parameter of the bridge arm of the converter in the state of permanent arm blocking; the third operating parameter includes a third bridge arm current value of the bridge arm of the converter and a duration of the third bridge arm current value;

[0050] If the third operating parameter satisfies the permanent overcurrent protection condition of the entire bridge arm, the entire converter is locked and the line switch is tripped.

[0051] In the above embodiment, by detecting that all bridge arms of the converter are not in a state of permanent bridge arm locking, further detection of the converter is performed to lock all bridge arms and shut down the converter, and at the same time, an application is made to trip the incoming line switch, thereby avoiding the impact of the expansion of the accident scope on the system and improving the safety and stability of the system.

[0052] In one embodiment, if the third operating parameter satisfies the full-bridge arm permanent overcurrent protection condition, then locking the entire converter and tripping the line switch includes:

[0053] If the logic judgment unit or the valve control unit detects that the current value of the third bridge arm is greater than the fourth set current of the permanent overcurrent protection of the full bridge arm and the duration of the third bridge arm current value is greater than the fourth set duration of the permanent overcurrent protection of the full bridge arm, the entire converter is locked and the line switch is tripped.

[0054] In the above embodiment, the permanent overcurrent protection of the entire bridge arm of the converter is judged on the logic judgment unit or the valve control unit side, which improves the overcurrent protection method and enhances the reliability of the converter overcurrent protection.

[0055] In one embodiment, the fourth set current value ranges from 2.0 to 3.0 rated current values, and the fourth set time value ranges from 0 us to 1000 us.

[0056] In the above embodiment, by setting the set current and duration of the permanent overcurrent protection of the entire bridge arm, the impact on the system caused by the expansion of the accident scope is avoided.

[0057] In a second aspect, the present application provides an overcurrent protection system for an energy storage valve. The system includes a valve control module, an overcurrent detection module, and a logic judgment module, wherein:

[0058] The overcurrent detection module is configured to perform overcurrent detection on the real-time operating parameters of the bridge arm of the converter; if it is detected that the real-time operating parameters meet the permanent locking condition of the bridge arm of the permanent overcurrent protection of the valve control module, a permanent overcurrent protection signal is generated and sent to the logic judgment module;

[0059] The logic judgment module is used to judge the received permanent overcurrent protection signal and obtain a judgment result; if the judgment result is that the bridge arm is permanently overcurrent, the permanent overcurrent protection signal is sent to the valve control module;

[0060] The valve control module is used to respond to the permanent overcurrent protection signal and permanently lock the bridge arm of the converter.

[0061] In a third aspect, the present application further provides a computer device. The computer device includes a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are performed:

[0062] Acquire real-time operating parameters of the bridge arm of the converter; the real-time operating parameters include at least a real-time bridge arm current value and a duration of the real-time bridge arm current value;

[0063] If the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent blocking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment;

[0064] If the result of the judgment is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked. In a fourth aspect, the present application also provides a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the following steps are implemented:

[0065] Acquire real-time operating parameters of the bridge arm of the converter; the real-time operating parameters include at least a real-time bridge arm current value and a duration of the real-time bridge arm current value;

[0066] If the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent blocking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment;

[0067] If the result of the judgment is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked. In a fifth aspect, the present application also provides a computer program product. The computer program product includes a computer program, and when the computer program is executed by a processor, the following steps are implemented:

[0068] Acquire real-time operating parameters of the bridge arm of the converter; the real-time operating parameters include at least a real-time bridge arm current value and a duration of the real-time bridge arm current value;

[0069] If the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent blocking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment;

[0070] If the result of the judgment is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked. The above description is only an overview of the technical solution of this application. In order to more clearly understand the technical means of this application, it can be implemented according to the contents of the description. In order to make the above and other purposes, features and advantages of this application more obvious and easy to understand, the following specifically describes the specific implementation methods of this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0072] FIG1 is a diagram illustrating an application environment of an overcurrent protection method for an energy storage valve according to an embodiment;

[0073] FIG2 is a schematic flow chart of an overcurrent protection method for an energy storage valve according to an embodiment;

[0074] FIG3 is a current diagram of overcurrent protection in one embodiment;

[0075] FIG4 is a schematic flow chart of a method for temporary overcurrent protection in one embodiment;

[0076] FIG5 is a schematic diagram of steps of a method for temporary overcurrent protection according to another embodiment;

[0077] FIG6 is a schematic flow chart of an overcurrent protection method for an energy storage valve in another embodiment;

[0078] FIG7 is a schematic flow chart of the steps of permanent overcurrent protection in one embodiment;

[0079] FIG8 is a schematic flow chart of an overcurrent protection method for an energy storage valve in another embodiment;

[0080] FIG9 is a data interaction diagram of an overcurrent protection method for an energy storage valve according to an embodiment;

[0081] FIG10 is a schematic structural diagram of an overcurrent protection system for an energy storage valve according to an embodiment;

[0082] FIG11 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0083] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0084] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned figure descriptions are intended to cover non-exclusive inclusions.

[0085] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0086] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0087] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0088] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0089] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0090] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0091] With the development of new energy technologies, energy storage systems have become one of the more important research areas in the field. New energy storage systems can achieve flexible control of energy storage system output power and optimize battery pack management capabilities. New energy storage systems, for example, are high-voltage direct-mounted energy storage systems in high-voltage grid applications. The energy storage valve control system is the core control device of the energy storage system, and valve-controlled overcurrent detection is key to the stable operation of the entire flexible DC converter valve. The current overcurrent protection method uses temporary overcurrent protection to provide overcurrent protection by locking and tripping. This simple overcurrent protection method has low reliability.

[0092] To address this technical problem, a method for overcurrent protection of an energy storage valve is proposed. It is applied in the application environment shown in Figure 1. The energy storage valve can be, but is not limited to, a high-voltage DC direct-mounted energy storage valve, an AC direct-mounted energy storage valve, or an MMC energy storage valve. The application environment shown in Figure 1 includes valve control hosts A and B, logic judgment devices A and B, overcurrent detection devices A, B, and C, and measurement units A, B, and C. Valve control hosts A and B are redundant, and logic judgment devices A and B are redundant. The overcurrent detection device detects the real-time operating parameters of the converter's bridge arm measured by the measurement unit; the real-time operating parameters include at least the real-time bridge arm current value and the duration of the real-time bridge arm current value. When the overcurrent detection device detects that the real-time operating parameters of the converter's bridge arm meet the permanent arm lockout conditions of the permanent overcurrent protection, it generates a permanent overcurrent protection signal and transmits the permanent overcurrent protection signal to the logic judgment device for judgment. If the judgment result is that the converter's bridge arm is permanently overcurrent, the valve control host permanently locks the converter's bridge arm. By segmenting the converter's overcurrent protection, when it is detected in real time that the converter's real-time bridge arm current value and duration meet the permanent arm lockout conditions of the permanent overcurrent protection, the corresponding converter arm is permanently locked. Based on the consideration of overcurrent protection, the overcurrent protection method is further improved, avoiding a single form of overcurrent protection and improving the reliability of the overcurrent protection.

[0093] It can be understood that temporary overcurrent protection can be understood as overcurrent stage I protection; permanent overcurrent protection, that is, single bridge arm permanent overcurrent protection can be understood as overcurrent stage II protection; full bridge arm permanent overcurrent protection can be understood as overcurrent stage III protection.

[0094] In one embodiment, as shown in FIG2 , a method for overcurrent protection of an energy storage valve is provided. The method is described by taking the application environment shown in FIG1 as an example, and includes the following steps:

[0095] Step 202: Acquire real-time operating parameters of the bridge arm of the converter. The real-time operating parameters at least include a real-time bridge arm current value and a duration of the real-time bridge arm current value.

[0096] The converter includes at least one bridge arm, each corresponding to an overcurrent protection device. CT coils are added at the beginning or end of the bridge arm to detect and protect the current in the bridge arm. The overcurrent protection device protects the energy storage valve. When the overcurrent protection device triggers (either an overcurrent protection operating signal or an overcurrent protection signal), the energy storage valve submodule is locked and a trip signal is sent. The final decision signal, derived through logical analysis, is sent to the valve control unit, which locks the energy storage valve and requests a branch trip signal. This embodiment uses one bridge arm of the converter as an example for illustration.

[0097] The real-time bridge arm current value can be measured by a measuring unit. The number of measuring units can be one, two, or three. There is no limitation on the number of measuring units here. There is a corresponding mapping relationship between the bridge arm current value and the bridge arm. The corresponding bridge arm can be determined based on the collected bridge arm current value. For example, as shown in FIG3 , it is the current value measured by the overcurrent protection in one embodiment, that is, the current flowing into the energy storage valve, as shown in the dotted area 1 marked in FIG3 . For ease of understanding, the overcurrent protection in this example is illustrated with a certain bridge arm of the converter.

[0098] In an energy storage valve, when overcurrent occurs, it is necessary to protect the bridge arm flow control valve by locking the bridge arm to improve safety. Overcurrent protection includes temporary overcurrent protection and permanent overcurrent protection. Temporary overcurrent protection can be understood as temporary overcurrent that can be restored. That is, overcurrent protection caused by temporary interference in the energy storage valve is temporarily locked. The valve body is unlocked after the overcurrent disappears. This does not affect the operation of the energy storage valve, and the valve control system has the ability to self-recover. Permanent overcurrent protection can be understood as the energy storage valve cannot automatically recover after the valve body is locked. Temporary overcurrent protection and permanent overcurrent protection can be implemented locally in the energy storage valve. For example, overcurrent protection can be implemented in the overcurrent detection device of the energy storage valve.

[0099] Specifically, the energy valve control system has the ability of self-recovery. After the energy storage valve performs temporary overcurrent protection, in order to further improve the overcurrent protection method, the bridge arm current of the bridge arm of the converter in the energy storage valve is detected in real time. If the bridge arm current value is detected to meet the set current for unlocking the temporary overcurrent protection, and the duration of the bridge arm current value also reaches the set duration corresponding to the unlocking, the bridge arm is unlocked, that is, the corresponding energy storage valve is unlocked, and the real-time operating parameters of the bridge arm of the converter in the energy storage valve are detected in real time.

[0100] Step 204: If the real-time operating parameters of the bridge arm of the converter meet the permanent arm blocking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated and sent to the logic judgment unit for judgment.

[0101] Step 206: If the judgment result is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked.

[0102] Among them, the permanent locking conditions of the bridge arm of permanent overcurrent protection include reaching the set current of permanent overcurrent protection and the set time of permanent overcurrent protection. The set current and set time of permanent overcurrent protection are expanded on the basis of the set current and set time on the basis of temporary overcurrent protection. The set current of permanent overcurrent protection is greater than the set current of temporary overcurrent protection lockout, and the set time of permanent overcurrent protection is greater than the set time of temporary overcurrent protection lockout.

[0103] When determining whether the real-time operating parameters of a bridge arm of a converter meet the permanent arm lockout conditions for permanent overcurrent protection, the determination can be made in the following manner: obtaining real-time operating parameters measured by at least one measurement unit, and determining whether the bridge arm of the converter meets the permanent arm lockout conditions for permanent overcurrent protection based on the at least one real-time operating parameter. When determining whether the permanent arm lockout conditions for permanent overcurrent protection are met based on the real-time operating parameters, it can be determined whether the number of temporary lockouts in the real-time operating parameters meets the permanent arm lockout conditions for permanent overcurrent protection, or whether the bridge arm current value and duration in the real-time operating parameters meet the permanent arm lockout conditions for permanent overcurrent protection.

[0104] It is understandable that when performing overcurrent protection on the energy storage valve, in order to improve the reliability, selectivity, sensitivity, speed, controllability, safety, etc. of the overcurrent protection, the execution steps of the overcurrent protection are executed by different processing units respectively.

[0105] Specifically, when the real-time operating parameters of the converter's bridge arm meet the permanent arm lockout conditions for permanent overcurrent protection, a permanent overcurrent protection signal is generated and sent to a logic judgment unit in the logic judgment device for judgment. If the logic judgment unit determines that permanent overcurrent protection is in effect, the valve control unit of the valve control host permanently locks the bridge arm of the converter. If all bridge arms of the converter are detected to be permanently locked, the line switch is directly tripped.

[0106] In the above embodiment, when overcurrent protection is performed by real-time detection of the operating parameters of the converter, when it is detected in real time that the real-time bridge arm current value and the duration of the converter meet the permanent arm locking condition of the permanent overcurrent protection, the bridge arm of the converter is permanently locked. On the basis of temporary overcurrent protection, permanent overcurrent of the bridge arm is further considered, and the bridge arm is locked when the permanent arm locking condition of the permanent overcurrent protection is met. The overcurrent of the converter is protected in sections, thereby improving the reliability of the overcurrent protection.

[0107] When overcurrent occurs in the converter, corresponding overcurrent protection measures need to be taken according to the type of overcurrent. According to different overcurrent protection measures, the overcurrent protection mode of the energy storage valve is improved to improve the reliability of overcurrent protection.

[0108] In one embodiment, a method for temporary overcurrent protection is provided, as shown in FIG4 , including the following steps:

[0109] Step 402: Acquire a first operating parameter of a bridge arm of the converter.

[0110] The first operating parameter includes at least the first bridge arm current value and the duration of the first bridge arm current value. Temporary overcurrent protection can also be understood as single bridge arm temporary overcurrent protection.

[0111] Specifically, when the energy storage valve operates normally, temporary overcurrent protection of the energy storage valve is enabled, and a first operating parameter of a bridge arm of the converter in the energy storage valve is detected in real time by at least one measuring unit. Based on the first operating parameter, on-site protection is performed in a local valve protection unit of the energy storage valve.

[0112] Step 404: If the first operating parameter satisfies the temporary overcurrent protection start-up condition, a temporary overcurrent protection signal is generated.

[0113] Among them, after the temporary overcurrent protection is locked, it will automatically recover and unlock the bridge arm when the preset unlocking conditions are met. The activation condition of the temporary overcurrent protection can be when the current value of the first bridge arm is greater than the first set current of the temporary overcurrent protection, and the overcurrent duration of the first bridge arm current value is greater than the first set duration of the temporary overcurrent protection. The release condition of the temporary overcurrent protection can be when the current value of the second bridge arm is less than the second set current of the temporary overcurrent protection, and the overcurrent duration of the second bridge arm current value is greater than the second set duration of the temporary overcurrent protection. The first set current is greater than the second set current, and the first set duration is less than the second set duration. The value range of the first set current is 1.2 to 2.0 rated current values, and the rated current value of 1.2 to 2.0 can be understood as (1.2 to 2.0) rated current values, that is, 1.2 to 2.0 times the rated current value; the value range of the second set current is 0 to 1.0 rated current value, and the rated current value of 0 to 1.0 can be understood as (0 to 1.0) rated current values, that is, 0 to 1.0 times the rated current value. Furthermore, the first set duration ranges from 0µs to 500µs, and the second set duration ranges from 0µs to 3000µs. The first set current and the first set duration are determined based on the temporary overcurrent protection characteristics of the energy storage valve, while the second set current and the second set duration are determined based on the self-recovery capability of the energy storage valve.

[0114] Step 406: Temporarily block the bridge arm of the converter based on the temporary overcurrent protection signal, and record the number of temporary blocking times of the bridge arm of the converter.

[0115] The recording of the temporary blocking times of the bridge arm of the converter can be understood as follows: when it is determined that the bridge arm of the converter is temporarily blocked, the temporary blocking times is increased by 1.

[0116] Step 408: Acquire a second operating parameter of the bridge arm of the converter.

[0117] The second operating parameter includes the second bridge arm current value and the duration of the second bridge arm current value.

[0118] Step 410: If the second operating parameter satisfies the overcurrent protection release condition, a release overcurrent protection signal is generated.

[0119] Among them, the overcurrent protection release condition can be that the second bridge arm current value is less than the second set current of the overcurrent protection release condition, the duration of the second bridge arm current value is greater than the second set duration of the overcurrent protection release condition, and the second set duration is greater than the first set duration.

[0120] Step 412: unlock the bridge arm of the converter based on the overcurrent protection release signal.

[0121] Specifically, if a temporary overcurrent protection action of a single bridge arm occurs and the bridge arm is locked, it is detected that the overcurrent protection function of stage I is enabled, and the real-time detection shows that the current of the second bridge arm is less than the second set current and the duration is greater than the second set time. The temporary overcurrent protection action returns, the single bridge arm locking flag is cleared, and the temporary overcurrent protection action signal, current value, and bridge arm locking times are sent to the logic judgment unit. The logic judgment unit performs a two-out-of-three judgment, and sends the judgment result to the unlocking signal to unlock the bridge arm.

[0122] It can be understood that in order to determine the reliability of the overcurrent protection of the energy storage valve, the energy storage valve can be hardware graded, and the overcurrent protection device can be implemented in a segmented manner. That is, the first operating parameters of the bridge arm of the converter are measured by three measuring units, and the collected first operating parameters are sent to the corresponding local valve protection units respectively, and on-site protection is performed by the valve protection units.

[0123] In one embodiment, if at least two valve protection units detect that the corresponding first bridge arm current value is greater than the first set current of the temporary overcurrent protection, and the overcurrent duration of the first bridge arm current value is greater than the first set duration of the temporary overcurrent protection, at least two candidate temporary overcurrent protection signals are generated; the at least two candidate temporary overcurrent protection signals are sent to the logic judgment unit, and the logic judgment unit makes a judgment based on the at least two temporary overcurrent protection signals to generate a temporary overcurrent protection signal. The temporary overcurrent protection signal is sent to the valve control unit, and the bridge arm of the converter is temporarily locked by the valve control unit. Among them, the valve protection unit and the logic judgment unit belong to different functional layers of the energy storage valve control system respectively, and the valve protection unit can also be called an overcurrent detection unit. The logic judgment unit can adopt "three-out-of-two judgment logic" when making a judgment. The number of valve control units can be two, and the two valve control units are redundant with each other.

[0124] Specifically, when the energy storage valve control system is operating normally, if the overcurrent protection function of stage I is enabled, the first operating parameter of the bridge arm is detected in real time. If the current value of the first bridge arm of the first operating parameter is greater than a first set current and lasts longer than a first set duration, temporary overcurrent protection is activated, a single bridge arm lockout flag is set, and the number of bridge arm lockouts is accumulated. At the same time, the overcurrent detection chassis sends the temporary overcurrent protection action signal, current value, and bridge arm lockout count of the chassis to the logic judgment unit. The logic judgment unit uses a two-out-of-three judgment logic to perform a two-out-of-three logical judgment based on the temporary overcurrent action signals of the three logic judgment units, and then sends the action signal to the valve control unit to temporarily lock the single bridge arm converter valve. Otherwise, the detection and judgment are continued. At least two overcurrent detection devices are used to detect and generate at least two candidate temporary overcurrent protection signals. The logic judgment device judges the at least two candidate temporary overcurrent protection signals and generates a temporary overcurrent protection signal, thereby improving the reliability of the temporary overcurrent protection.

[0125] FIG5 is a schematic diagram of the steps of a temporary overcurrent protection method in one embodiment. The energy storage valve control system can be a novel energy storage valve control system, and the temporary overcurrent protection can be understood as overcurrent stage I protection. After power-on initialization, the novel energy storage valve control system operates normally, with arm lockout count N = 0. Overcurrent stage I protection is enabled, and the arm current is monitored in real time. If the arm current exceeds a first set current Iset1 and persists for longer than a first set duration It1, temporary overcurrent protection is activated, a single arm lockout flag is set, and the arm lockout count N = N + 1 is accumulated. Simultaneously, the overcurrent detection chassis transmits its temporary overcurrent protection action signal, current value, and arm lockout count to a logic determination unit. The logic determination unit performs a two-out-of-three logical analysis based on the temporary overcurrent action signals from the three valve protection units, and then transmits the action signal to the valve control unit to temporarily lock the single-arm converter valve. Otherwise, continuous detection and determination are performed.

[0126] If a single-arm temporary overcurrent protection action occurs and the bridge arm is locked, it is detected that the overcurrent protection function of stage I is enabled, and the real-time detection of the bridge arm current is less than the second set current Iset2 and the duration is greater than the second set time It2. The temporary overcurrent protection action returns, the single-arm locking flag is cleared, and the temporary overcurrent protection action signal, current value, and bridge arm locking times are sent to the logic judgment unit for three-out-two judgment. The judgment result is sent to the unlocking signal to unlock the bridge arm.

[0127] In the above embodiment, when the bridge arm of the converter is temporarily overcurrent, it is locked. By further judging whether the overcurrent protection is released, the temporary lock is unlocked considering the recovery ability of the energy storage valve itself, so as to avoid the temporary lock directly tripping the line switch and causing the entire station to stop operating.

[0128] In another embodiment, as shown in FIG6 , a method for overcurrent protection of an energy storage valve is provided. The method is described by taking the application environment in FIG1 as an example, and includes the following steps:

[0129] Step 602: When the bridge arm of the converter is released from temporary blocking, obtain the real-time operating parameters of the bridge arm of the converter; the real-time operating parameters include the number of temporary blocking times.

[0130] The temporary closing times are the times the bridge arm is temporarily closed. Each time the energy storage valve is temporarily closed, the temporary closing times of the corresponding bridge arm are updated. The updating method may be to accumulate the temporary closing times of the bridge arm.

[0131] Step 604: If it is detected that the number of temporary blocking times is greater than a set threshold, a permanent overcurrent protection signal is generated.

[0132] The threshold can be pre-set based on actual needs. It represents the threshold for the number of temporary lockouts and can be manually set based on project requirements. When the number of temporary lockouts N during operation exceeds the set threshold M, the system enters permanent lockout. The set threshold can be 50 times, and the set threshold is not greater than 120 times. Permanent lockout of a bridge arm can be understood as permanent lockout of a single bridge arm.

[0133] Step 606: Send the permanent overcurrent protection signal to the logic judgment unit for judgment. If the judgment result is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked.

[0134] In one embodiment, if at least two valve protection units detect that the number of temporary lockouts exceeds a set threshold, at least two candidate permanent overcurrent protection signals are generated; the at least two candidate permanent overcurrent protection signals are sent to a logic judgment unit, which makes a judgment based on the at least two temporary and permanent protection signals to generate a permanent overcurrent protection signal. The temporary overcurrent protection signal is sent to a valve control unit, which permanently locks the bridge arm of the converter. In other words, at the energy storage valve, local permanent overcurrent protection is performed by at least two valve protection units, the generated candidate permanent overcurrent protection signal is sent to the logic judgment unit for judgment, and the valve control unit permanently locks the single-bridge-arm converter valve. The energy storage valve protection hardware is graded and segmented, improving the overcurrent protection method and enhancing the reliability of the overcurrent protection.

[0135] In the above embodiment, when a temporary lockout is followed by unlocking, the number of temporary lockouts is counted. If the number of temporary lockouts exceeds a set threshold, the inverter arm is permanently locked. By implementing segmented overcurrent protection for the inverter arm, additional overcurrent protection methods are provided, thereby improving the reliability of overcurrent protection.

[0136] In one embodiment, as shown in FIG7 , a permanent overcurrent protection step is provided. The method is described by taking the application environment in FIG1 as an example, including the following steps:

[0137] Step 702: Acquire real-time operating parameters of the bridge arm of the converter.

[0138] Specifically, when the bridge arm of the converter is released from temporary blocking, the real-time operating parameters of the bridge arm of the converter are obtained. Alternatively, the real-time operating parameters of the bridge arm of the converter are directly obtained.

[0139] Step 704: If it is detected that the number of temporary blocking times in the real-time operating parameters is greater than a set threshold, the bridge arm of the converter is permanently blocked.

[0140] Specifically, when the energy storage valve is operating normally, permanent overcurrent protection is enabled. If it is detected that the number of temporary lockouts is greater than the set threshold, a permanent overcurrent protection signal is generated, and a single bridge arm permanent lockout flag is set for the bridge arm corresponding to the real-time bridge arm current value, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment. If it is judged that the bridge arm corresponding to the real-time bridge arm current value is permanently overcurrent, the permanent overcurrent protection signal is sent to the valve control unit for control, and the bridge arm of the converter is permanently locked based on the permanent overcurrent protection signal.

[0141] Step 706: If it is detected that the real-time bridge arm current value and the duration in the real-time operating parameters meet the bridge arm permanent blocking condition of the permanent overcurrent protection, the bridge arm of the converter is permanently blocked.

[0142] The permanent arm lockout condition for the permanent overcurrent protection can be that the real-time arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection. The third set current value ranges from 1.5 to 2.0 rated current values, and the third set duration value ranges from 0 us to 1000 us. The 1.5 to 2.0 rated current value can be understood as (1.5 to 2.0) rated current values, that is, 1.5 to 2.0 times the rated current value. Specifically, when the energy storage valve is operating normally, permanent overcurrent protection is enabled. If it is detected that the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the bridge arm corresponding to the real-time bridge arm current value is set with a single bridge arm permanent locking flag, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment. If it is judged that the bridge arm corresponding to the real-time bridge arm current value is permanently overcurrent, the permanent overcurrent protection signal is sent to the valve control unit for control, and the bridge arm of the converter is permanently locked based on the permanent overcurrent protection signal.

[0143] Furthermore, in view of the fact that the existing energy storage valve has a single overcurrent protection mode and low reliability of overcurrent protection, the hardware of the energy storage valve is layered to achieve overcurrent protection, improve overcurrent protection and enhance the reliability of overcurrent protection.

[0144] In one embodiment, if at least two valve protection units detect that the corresponding real-time bridge arm current value is greater than the third set current of permanent overcurrent protection and the duration is greater than the third set duration of permanent overcurrent protection, at least two candidate permanent overcurrent protection signals are generated; the at least two candidate permanent overcurrent protection signals are sent to the logic judgment unit, and the logic judgment unit makes a judgment based on the at least two candidate permanent overcurrent protection signals to generate a permanent overcurrent protection signal. The permanent overcurrent protection signal is sent to the valve control unit to permanently lock the bridge arm of the converter. When performing permanent overcurrent protection, the valve protection unit performs on-site protection in a hardware hierarchical and overcurrent protection segmented manner. After generating the candidate permanent overcurrent protection signal, the logic judgment unit performs a logical judgment to determine the final permanent overcurrent protection signal and sends it to the valve control unit to permanently lock the bridge arm. This allows for multi-level and multi-directional overcurrent protection of the energy storage valve, thereby improving the reliability of the energy storage valve.

[0145] In the above embodiment, by obtaining the number of temporary blocking times of the bridge arm of the converter, or by real-time detecting the bridge arm current value and the duration of the bridge arm current value, it is determined whether permanent overcurrent protection is triggered. By layering the system hardware and segmenting the overcurrent protection, the reliability of the energy storage valve overcurrent protection is improved.

[0146] In another embodiment, an overcurrent protection method for an energy storage valve is provided. The method is described by taking the application environment in FIG. 1 as an example, as shown in FIG. 8 , including the following steps:

[0147] Step 802: Acquire real-time operating parameters of the bridge arm of the converter; the real-time operating parameters at least include the real-time bridge arm current value and the duration of the real-time bridge arm current value.

[0148] Step 804: When the real-time operating parameters of the bridge arm of the converter meet the permanent blocking condition of the bridge arm of the permanent overcurrent protection, a permanent overcurrent protection signal is generated and sent to the logic judgment unit for judgment.

[0149] Among them, the temporary overcurrent protection and permanent overcurrent protection of the energy storage valve can be achieved by the above-mentioned methods, which will not be described in detail here.

[0150] Step 806: If the result of the judgment is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked.

[0151] Step 808: If it is detected that all bridge arms of the converter are not in the bridge arm permanent blocking state, obtain the third operating parameter of the bridge arm of the converter that is in the bridge arm permanent blocking state.

[0152] The third operating parameter includes a third bridge arm current value of the bridge arm of the converter and a duration of the third bridge arm current value. The third operating parameter can be obtained by the measuring unit.

[0153] It can be understood that the full-arm permanent overcurrent protection is after the single-arm permanent overcurrent protection is executed. If it is detected that all the bridge arms of the converter are not in the permanent arm lock state, in order to avoid three-phase imbalance and serious impact on the other two bridge arms, the circuit breaker should be tripped in time to prevent the expansion of the fault.

[0154] Step 810: If the third operating parameter satisfies the full-bridge arm permanent overcurrent protection condition, the entire converter is locked and the line switch is tripped.

[0155] Among them, the permanent overcurrent protection condition for the entire bridge arm can be that after the permanent overcurrent protection of a single bridge arm, the bridge arm current value detected in real time is greater than the fourth set current of the permanent overcurrent protection of the entire bridge arm and the duration is greater than the fourth set duration of the permanent overcurrent protection of the entire bridge arm. The fourth set current value range is 2.0 to 3.0 rated current values, and the fourth set duration range is 0us to 1000us. The fourth set current value and the fourth set duration are determined based on the electrical and insulation tolerance time of other bridge arms in the energy storage system, which can avoid the impact on the system caused by the expansion of the accident scope. The rated current value of 2.0 to 3.0 can be understood as (2.0 to 3.0) rated current values, that is, 2.0 to 3.0 times the rated current value.

[0156] It is understandable that the energy storage valve has more than one bridge arm. After detecting the permanent overcurrent protection of a single bridge arm, if it is detected that the third operating parameter of any bridge arm meets the permanent overcurrent protection condition of the entire bridge arm, the entire converter is locked and the line switch is tripped.

[0157] Specifically, when the energy storage valve is operating normally, the full-arm permanent overcurrent protection function is enabled. It detects whether any arm has a permanent overcurrent event. If not, the detection continues. If so, it determines whether all arms are fully locked. If so, the overcurrent protection ends. If not, the current value of the third arm of the locked arm is detected in real time. If the third arm current value exceeds a fourth set current and lasts for a period longer than a fourth set time, the three-phase full-arm converter is locked, the full-arm converter permanent lockout flag is set, and the line switch is tripped, pending shutdown for maintenance.

[0158] In the above embodiment, by segmenting the overcurrent protection of the energy storage valve, temporary overcurrent protection is used to implement overcurrent protection caused by temporary interference in the bridge arm, and the valve body is temporarily locked. After the overcurrent disappears, the valve body is unlocked without affecting the operation of the energy storage valve. The valve control system has the ability to self-recover; on the basis of temporary overcurrent protection, the time limit and the set value are extended. After the requirements of the set value and the time limit are met, the single bridge arm permanent valve is locked to protect the bridge arm flow converter valve; on the basis of permanent overcurrent protection, after the permanent locking of a single bridge arm is detected, the entire bridge arm is locked and the incoming line switch is opened according to the electrical and insulation tolerance time of the other bridge arms, thereby avoiding the impact on the system caused by the expansion of the accident scope, improving the overcurrent protection method, and improving the reliability of the energy storage valve.

[0159] On the basis of segmenting the overcurrent protection mode of the energy storage valve, by grading the system hardware and realizing permanent overcurrent protection of the whole bridge arm on the side of the logic judgment unit or the valve control unit, the overcurrent protection mode is further improved, and the reliability of the energy storage system is enhanced.

[0160] In one embodiment, if the logic judgment unit or the valve control unit detects that the current value of the third bridge arm is greater than the fourth set current of the permanent overcurrent protection of the full bridge arm and the duration of the third bridge arm current value is greater than the fourth set duration of the permanent overcurrent protection of the full bridge arm, the entire converter is locked and the line switch is tripped.

[0161] Specifically, when the energy storage valve is operating normally, after the permanent overcurrent protection is triggered, the protection function of the permanent overcurrent protection of the full-bridge arm is enabled, and the permanent overcurrent protection of the full-bridge arm is performed through the logic judgment unit or the valve control unit. If the logic judgment unit or the valve control unit detects that the current value of the third bridge arm is greater than the fourth set current of the permanent overcurrent protection of the full-bridge arm and the duration of the current value of the third bridge arm is greater than the fourth set duration of the permanent overcurrent protection of the full-bridge arm, the three-phase full-bridge arm converter is locked, the permanent locking flag of the full-bridge arm converter is set, and the line switch is tripped, waiting for shutdown and maintenance.

[0162] In one embodiment, a data interaction diagram of an overcurrent protection method for an energy storage valve is shown in Figure 9. The method includes valve control units A and B, logic judgment units A and B, valve protection units A, B, and C, and measurement units A, B, and C. Valve control units A and B are redundant, and logic judgment units A and B are redundant. Overcurrent protection stages I and II of the energy storage valve are implemented using the valve protection unit, while overcurrent protection stage III is implemented using the logic judgment unit or the valve control unit. The energy storage valve control system operates normally after power-on initialization. The bridge arm current of the converter in the energy storage valve control system is measured by three measuring units. The three valve protection units detect the first operating parameter of the bridge arm in real time. If the first bridge arm current value of the first operating parameter is greater than the first set current and the duration is greater than the first set time, the temporary overcurrent protection is activated, the single bridge arm locking flag is set, and the number of bridge arm locking times is accumulated. At the same time, the overcurrent detection chassis sends the temporary overcurrent protection action signal, current value, and bridge arm locking times of the chassis to the logic judgment unit. The logic judgment unit performs a three-out-of-two logic judgment based on the temporary overcurrent action signals of the three logic judgment units based on the three-out-of-two judgment logic, and then sends the action signal to the valve control unit. The single bridge arm converter valve is temporarily locked through the valve control unit. Otherwise, the detection and judgment are continued.

[0163] If a single bridge arm temporary overcurrent protection action occurs and the bridge arm is locked, the three valve protection units detect that the overcurrent protection function of stage I is enabled, and the three valve protection units detect that the current of the second detection bridge arm is less than the second set current Iset2 and the duration is greater than the second set time It2, the temporary overcurrent protection action returns, the single bridge arm locking flag is cleared, and the temporary overcurrent protection action signal, current value, and bridge arm locking times are sent to the logic judgment unit for three-out-two judgment, and the judgment result is sent to the unlocking signal, and the bridge arm is unlocked through the valve control unit. On the basis of overcurrent section I, when the energy storage valve control system is operating normally, the protection of overcurrent section II is enabled. If the three valve protection units detect that the number of temporary lockouts is greater than the set threshold, or the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, three single-bridge arm permanent overcurrent protection actions are generated, and the single-bridge arm lockout flag is set. At the same time, the valve protection unit sends the permanent overcurrent protection action signal, current value, and bridge arm lockout times to the logic judgment unit, and after a two-out-of-three logic judgment is performed based on the permanent overcurrent action signals of the three valve protection units, the action signal is sent to the valve control unit for permanent locking of the single-bridge arm converter valve. Otherwise, continuous detection and judgment are performed.

[0164] When the energy storage valve control system is operating normally, after the permanent overcurrent protection is triggered, the protection function of the permanent overcurrent protection of the full-bridge arm is enabled, and the permanent overcurrent protection of the full-bridge arm is performed through the logic judgment unit or the valve control unit. If the logic judgment unit or the valve control unit detects that the current value of the third bridge arm is greater than the fourth set current of the permanent overcurrent protection of the full-bridge arm and the duration of the current value of the third bridge arm is greater than the fourth set duration of the permanent overcurrent protection of the full-bridge arm, the three-phase full-bridge arm converter is locked, the permanent locking flag of the full-bridge arm converter is set, and the line switch is tripped, waiting for shutdown and maintenance.

[0165] It can be understood that after temporary overcurrent protection is activated, overcurrent protection in Section I, which has a low set value and a low time limit, can be discontinued when the current returns to normal. A permanent lockout occurs when Section I lockout exceeds the limit, or when the high set value and time limit of Section II are exceeded. Section III locks out other bridge arms after Section II is activated and the high current set value and time limit are exceeded, preventing the scope of the accident from expanding. Specifically, by dividing the bridge arm overcurrent protection into Section III, with Sections I and II protected by the valve protection unit and Section III protected by the logic judgment unit or valve control unit, and employing energy storage valve protection with hardware tiering and software segmentation, a comprehensive, multi-layered approach to overcurrent protection is implemented, achieving selective fault isolation at the time of a fault, improving the overcurrent protection strategy, and enhancing the reliability of the energy storage valve.

[0166] Based on the same inventive concept, the embodiments of the present application also provide an energy storage valve for implementing the above-mentioned energy storage valve overcurrent protection method. The solution provided by this system is similar to the solution described in the above-mentioned method. Therefore, the specific limitations of the embodiments of the overcurrent protection system for one or more energy storage valves provided below can be found in the above-mentioned limitations of the overcurrent protection method for energy storage valves, and will not be repeated here.

[0167] In one embodiment, as shown in FIG10 , an overcurrent protection system for an energy storage valve is provided. The system includes an overcurrent detection module 1002 , a logic judgment module 1004 , and a valve control module 1006 , wherein:

[0168] The overcurrent detection module 1002 is used to perform overcurrent detection on the real-time operating parameters of the bridge arm of the converter; if it is detected that the real-time operating parameters meet the permanent locking condition of the bridge arm of the permanent overcurrent protection of the valve control module, a permanent overcurrent protection signal is generated and sent to the logic judgment module.

[0169] The logic judgment module 1004 is used to judge the received permanent overcurrent protection signal and obtain a judgment result; if the judgment result is that the bridge arm is permanently overcurrent, the permanent overcurrent protection signal is sent to the valve control module 1006.

[0170] The valve control module 1006 is used to respond to the permanent overcurrent protection signal and permanently lock the bridge arm of the converter.

[0171] In the above embodiment, overcurrent protection is performed by real-time detection of the operating parameters of the converter. When it is detected in real time that the real-time bridge arm current value and the duration of the converter meet the permanent arm permanent locking condition of the permanent overcurrent protection, the permanent overcurrent protection signal is sent to the logic judgment unit to achieve permanent arm locking of the bridge arm of the converter. When the permanent arm locking condition of the permanent overcurrent protection is met, the bridge arm is locked and the corresponding bridge arm of the converter is protected from overcurrent, instead of directly locking the entire converter and tripping the line switch. The overcurrent protection of the converter is segmented, thereby improving the reliability of the overcurrent protection.

[0172] Optionally, in one embodiment, the overcurrent detection module 1002 is also used to perform overcurrent detection on the first operating parameter of the bridge arm of the converter. If the first operating parameter meets the temporary overcurrent protection start-up condition, a temporary overcurrent protection signal is generated, the number of temporary locking times of the bridge arm of the converter is recorded, and the temporary overcurrent protection signal is sent to the logic judgment module.

[0173] Optionally, in one embodiment, the logic judgment module 1004 is further configured to judge the received temporary overcurrent protection signal to obtain a judgment result; if the judgment result is temporary overcurrent, the temporary overcurrent protection signal is sent to the valve control module.

[0174] Optionally, in one embodiment, the valve control module 1006 is further configured to temporarily lock the bridge arm of the converter in response to a temporary overcurrent protection signal.

[0175] Optionally, in one embodiment, the overcurrent detection module 1002 is also used to perform overcurrent detection on the second operating parameter of the bridge arm of the converter. If the second operating parameter meets the overcurrent protection release condition, an overcurrent protection release signal is generated and the overcurrent protection release signal is sent to the logic judgment module 1004.

[0176] Optionally, in one embodiment, the logic judgment module 1004 is further configured to judge the received overcurrent protection release signal to obtain a judgment result; if the judgment result is that the overcurrent is released, the overcurrent protection release signal is sent to the valve control module.

[0177] Optionally, in one embodiment, the valve control module 1006 is further configured to unlock the bridge arm of the converter in response to the overcurrent protection release signal.

[0178] Optionally, in one embodiment, the logic judgment module 1004 is also used to perform overcurrent detection on the third operating parameter of the bridge arm of the converter that is in permanent arm locking when it is detected that all bridge arms of the converter are not in permanent arm locking; if the third operating parameter meets the full-bridge-arm permanent overcurrent protection condition, a full-bridge-arm permanent overcurrent protection signal is generated; and the full-bridge-arm permanent overcurrent protection signal is sent to the valve control module 1006.

[0179] Optionally, in one embodiment, the valve control module 1006 is further configured to respond to a full-bridge arm permanent overcurrent protection signal to lock the entire converter and trip the line switch.

[0180] Optionally, in one embodiment, the valve control module 1006 is further used to perform overcurrent detection on the third operating parameter of the bridge arm of the converter that is in permanent arm lock when it is detected that all bridge arms of the converter are not in permanent arm lock. If the third operating parameter meets the permanent overcurrent protection condition of the entire bridge arm, the entire converter is locked and the line switch is tripped.

[0181] Optionally, in one embodiment, the overcurrent detection module 1002 is also used to generate at least two candidate temporary overcurrent protection signals if at least two valve protection modules detect that the corresponding first bridge arm current value is greater than the first set current of the temporary overcurrent protection, and the overcurrent duration of the first bridge arm current value is greater than the first set duration of the temporary overcurrent protection; and send the at least two candidate temporary overcurrent protection signals to the logic judgment module.

[0182] Optionally, the logic judgment module 1004 is further configured to make a judgment based on at least two temporary overcurrent protection signals to generate a temporary overcurrent protection signal.

[0183] Optionally, the valve control module 1006 is further configured to temporarily block a bridge arm of the converter.

[0184] Optionally, in one embodiment, the overcurrent detection module 1002 is further configured to generate a permanent overcurrent protection signal if it is detected that the number of temporary blocking times is greater than a set threshold.

[0185] Optionally, in one embodiment, the overcurrent detection module 1002 is also used to generate a permanent overcurrent protection signal when the number of temporary lockouts is less than a set threshold and the real-time bridge arm current value and duration meet the permanent lockout conditions of the bridge arm for permanent overcurrent protection.

[0186] Optionally, in one embodiment, the overcurrent detection module 1002 is also used to generate a permanent overcurrent protection signal if the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, and send the permanent overcurrent protection signal to the logic judgment module for judgment.

[0187] Optionally, in one embodiment, the logic judgment module 1004 is further used to make a judgment based on the at least two candidate permanent overcurrent protection signals generated by the overcurrent detection module 1002 if at least two candidate permanent overcurrent protection signals are received; if at least one candidate permanent overcurrent protection signal indicates that the bridge arm of the converter is permanently overcurrent, it is determined that the bridge arm of the converter is permanently overcurrent.

[0188] Optionally, in one embodiment, the valve control module 1006 is further configured to permanently lock the bridge arm of the converter based on the permanent overcurrent protection signal.

[0189] Optionally, in one embodiment, the valve control module 1006 is further configured to lock the entire converter and trip the line switch if the third operating parameter satisfies the full-arm permanent overcurrent protection condition. The various modules of the energy storage valve overcurrent protection system described above can be implemented in whole or in part via software, hardware, or a combination thereof. These modules can be embedded in or independent of a processor in a computer device in hardware form, or stored in a computer device memory in software form, allowing the processor to call and execute the corresponding operations of each module.

[0190] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be shown in Figure 11. The computer device includes a processor, memory, a communication interface, a display screen, and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner. The wireless manner may be achieved through WiFi, a mobile cellular network, NFC (near field communication), or other technologies. When the computer program is executed by the processor, an overcurrent protection method for an energy storage valve is implemented. The display screen of the computer device may be a liquid crystal display or an electronic ink display screen. The input device of the computer device may be a touch layer covering the display screen, or may be a key, trackball, or touchpad provided on the computer device housing, or may be an external keyboard, touchpad, or mouse.

[0191] Those skilled in the art will understand that the structure shown in FIG11 is merely a block diagram of a portion of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0192] In one embodiment, a computer device is further provided, including a memory and a processor. The memory stores a computer program, and the processor implements the steps in the above method embodiments when executing the computer program.

[0193] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0194] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0195] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0196] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, database or other media used in the embodiments provided in this application may include at least one of non-volatile and volatile memory. Non-volatile memory may include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory may include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, distributed databases based on blockchains. The processor involved in the various embodiments provided herein may be, but are not limited to, a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic unit, a data processing logic unit based on quantum computing, and the like.

[0197] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0198] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present patent application shall be determined by the appended claims.

Claims

1. A method for overcurrent protection of an energy storage valve, characterized in that: The method comprises: Acquire real-time operating parameters of the bridge arm of the converter; the real-time operating parameters include at least a real-time bridge arm current value and a duration of the real-time bridge arm current value; If the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent blocking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment; If the judgment result is that the bridge arm of the converter is permanently overcurrent, the bridge arm of the converter is permanently locked.

2. The method according to claim 1, characterized in that Before obtaining the real-time operating parameters of the bridge arm of the converter, the method further includes: Acquiring a first operating parameter of a bridge arm of the converter; If the first operating parameter meets the temporary overcurrent protection start condition, a temporary overcurrent protection signal is generated; temporarily blocking the bridge arm of the converter based on the temporary overcurrent protection signal, and recording the number of temporary blocking times of the bridge arm of the converter; Obtaining a second operating parameter of a bridge arm of the converter; If the second operating parameter satisfies the overcurrent protection release condition, generating an overcurrent protection release signal; The bridge arm of the converter is unlocked based on the overcurrent protection release signal.

3. The method according to claim 2, characterized in that The first operating parameter includes a first bridge arm current value and a duration of the first bridge arm current value. If the first operating parameter satisfies a temporary overcurrent protection start condition, generating a temporary overcurrent protection signal includes: If at least two valve protection units detect that the corresponding first bridge arm current value is greater than the first set current of the temporary overcurrent protection, and the overcurrent duration of the first bridge arm current value is greater than the first set duration of the temporary overcurrent protection, at least two candidate temporary overcurrent protection signals are generated; At least two of the candidate temporary over-current protection signals are sent to a logic judgment unit, and the logic judgment unit makes a judgment based on the at least two temporary over-current protection signals to generate a temporary over-current protection signal.

4. The method according to claim 3, characterized in that Temporarily blocking the bridge arm of the converter based on the temporary overcurrent protection signal includes: The temporary overcurrent protection signal is sent to a valve control unit, and the bridge arm of the converter is temporarily blocked by the valve control unit.

5. The method according to claim 2, characterized in that The first set current has a value range of 1.2 to 2.0 rated current values, and the first set time has a value range of 0 to 500 us.

6. The method according to claim 2, characterized in that The temporary overcurrent protection release condition includes a second set current and a second set time, the first set current is greater than the second set current, the first set time is less than the second set time, the second set current value range is 0 to 1.0 rated current value, and the second set time value range is 0 to 3000us.

7. The method according to claim 1, characterized in that The real-time operating parameters also include the number of temporary blocking times. If the real-time operating parameters of the bridge arm of the converter meet the permanent blocking condition of the bridge arm for permanent overcurrent protection, a permanent overcurrent protection signal is generated, including: If it is detected that the number of temporary blocking times is greater than a set threshold, a permanent overcurrent protection signal is generated.

8. The method according to claim 1, characterized in that The real-time operating parameters also include the number of temporary blocking times. If the real-time operating parameters of the bridge arm of the converter meet the permanent blocking condition of the bridge arm for permanent overcurrent protection, a permanent overcurrent protection signal is generated, including: When the number of temporary blocking times is less than a set threshold, if the real-time bridge arm current value and the duration meet the bridge arm permanent blocking condition of permanent overcurrent protection, a permanent overcurrent protection signal is generated.

9. The method according to claim 1, characterized in that If the real-time operating parameters of the bridge arm of the converter meet the permanent arm permanent blocking condition of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment, including: If the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, a permanent overcurrent protection signal is generated and sent to the logic judgment unit for judgment.

10. The method according to claim 9, characterized in that If the real-time bridge arm current value is greater than the third set current of the permanent overcurrent protection and the duration is greater than the third set duration of the permanent overcurrent protection, a permanent overcurrent protection signal is generated, and the permanent overcurrent protection signal is sent to the logic judgment unit for judgment, including: If at least two valve protection units detect that the corresponding real-time bridge arm current value is greater than the third set current of permanent overcurrent protection and the duration is greater than the third set duration of permanent overcurrent protection, at least two candidate permanent overcurrent protection signals are generated; Sending at least two of the candidate permanent over-current protection signals to a logic judgment unit, and performing a judgment by the logic judgment unit based on the at least two candidate permanent over-current protection signals; If at least one of the candidate permanent overcurrent protection signals indicates that the bridge arm of the converter is permanently overcurrent, it is determined that the bridge arm of the converter is permanently overcurrent.

11. The method according to claim 10, characterized in that If the bridge arm of the converter is permanently overcurrented, the bridge arm of the converter is permanently locked, comprising: The permanent overcurrent protection signal is sent to a valve control unit, and the bridge arm of the converter is permanently locked by the valve control unit.

12. The method according to claim 9, characterized in that The third set current has a value range of 1.5 to 2.0 of the rated current value, and the third set time has a value range of 0 to 1000 us.

13. The method according to any one of claims 1, 8 or 9, characterized in that: The method further comprises: If it is detected that all bridge arms of the converter are not in the state of permanent arm blocking, obtaining a third operating parameter of the bridge arm of the converter in the state of permanent arm blocking; the third operating parameter includes a third bridge arm current value of the bridge arm of the converter and a duration of the third bridge arm current value; If the third operating parameter satisfies the permanent overcurrent protection condition of the entire bridge arm, the entire converter is locked and the line switch is tripped.

14. The method according to claim 13, characterized in that If the third operating parameter satisfies the full-bridge arm permanent overcurrent protection condition, the entire converter is locked and the line switch is tripped, comprising: If the logic judgment unit or the valve control unit detects that the current value of the third bridge arm is greater than the fourth set current of the permanent overcurrent protection of the full bridge arm and the duration of the third bridge arm current value is greater than the fourth set duration of the permanent overcurrent protection of the full bridge arm, the entire converter is locked and the line switch is tripped.

15. The method according to claim 14, characterized in that The fourth set current value range is 2.0 to 3.0 rated current values, and the fourth set time value range is 0 to 1000 us.

16. An overcurrent protection system for an energy storage valve, characterized in that: The system includes a valve control module, an overcurrent detection module and a logic judgment module, wherein: The overcurrent detection module is configured to perform overcurrent detection on the real-time operating parameters of the bridge arm of the converter; if it is detected that the real-time operating parameters meet the permanent locking condition of the bridge arm of the permanent overcurrent protection of the valve control module, a permanent overcurrent protection signal is generated and sent to the logic judgment module; The logic judgment module is used to judge the received permanent overcurrent protection signal and obtain a judgment result; if the judgment result is that the bridge arm is permanently overcurrent, the permanent overcurrent protection signal is sent to the valve control module; The valve control module is used to respond to the permanent overcurrent protection signal and permanently lock the bridge arm of the converter.

17. The system according to claim 16, wherein: The overcurrent detection module is configured to perform overcurrent detection on the acquired first operating parameter of the bridge arm of the converter, and if the first operating parameter satisfies a temporary overcurrent protection initiation condition, generate a temporary overcurrent protection signal, record the number of temporary blocking times of the bridge arm of the converter, and transmit the temporary overcurrent protection signal to the logic judgment module; The logic judgment module is used to judge the received temporary overcurrent protection signal and obtain a judgment result; if the judgment result is temporary overcurrent, the temporary overcurrent protection signal is sent to the valve control module; The valve control module is configured to temporarily lock the bridge arm of the converter in response to the temporary overcurrent protection signal; The overcurrent detection module is further configured to perform overcurrent detection on the acquired second operating parameter of the bridge arm of the converter, and if the second operating parameter satisfies an overcurrent protection release condition, generate an overcurrent protection release signal, and send the overcurrent protection release signal to the logic judgment module; The logic judgment module is used to judge the received overcurrent protection release signal to obtain a judgment result; if the judgment result is that the overcurrent is released, the overcurrent protection release signal is sent to the valve control module; The valve control module is used to respond to the overcurrent protection release signal to unlock the bridge arm of the converter.

18. The system according to claim 16, wherein: The logic judgment module is further configured to perform overcurrent detection on a third operating parameter of a bridge arm of the converter that is in the permanent arm blocking state when detecting that all bridge arms of the converter are not in the permanent arm blocking state; If the third operating parameter satisfies the full-bridge-arm permanent overcurrent protection condition, a full-bridge-arm permanent overcurrent protection signal is generated; Sending the full-bridge arm permanent overcurrent protection signal to the valve control module; The valve control module is used to respond to the full-bridge arm permanent overcurrent protection signal, lock the entire converter and trip the line switch.

19. The system according to claim 16, wherein: The valve control module is also used to perform overcurrent detection on the third operating parameter of the bridge arm of the converter that is in permanent arm locking when it is detected that all bridge arms of the converter are not in permanent arm locking. If the third operating parameter meets the permanent overcurrent protection condition of the entire bridge arm, the entire converter is locked and the line switch is tripped.

20. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 16 are implemented.

21. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 16 are implemented.

22. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 16 are implemented.

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