An IEC61850-based energy storage system communication protocol optimization method

Abstract

The application relates to the technical field of power system communication, and discloses an energy storage system communication protocol optimization method based on IEC61850, which comprises the following steps: embedding an extensible mask field in a message of an MMS confirmation type protocol data unit, preset bit positions of the extensible mask field one-to-one correspond to each interactive variable in the message, and the state of each bit position is used for representing the confirmation receiving state of the corresponding interactive variable; dividing each interactive variable into a key variable and a non-key variable according to the importance level of interactive data; and analyzing the extensible mask field at a receiving end. The key variable is instantaneously confirmed and the non-key variable is aggregated and replied through the extensible mask field, redundancy interaction is eliminated, batch control instruction response delay is reduced to the millisecond level, and thus the control communication delay is reduced; and the traditional fixed window limit is broken through, the MMS-TPO sending window scale is dynamically self-adaptively adjusted through real-time monitoring of link round trip time, the transmission stability is ensured, and the cluster total calling efficiency is greatly improved.

Description

Technical Field

[0001] This application relates to the field of power system communication technology, and for example to a method, apparatus, equipment, storage medium and product for optimizing communication protocols of energy storage systems based on IEC61850. Background Technology

[0002] As an international standard for power system automation, the IEC 61850 protocol uses the GOOSE and MMS protocols for real-time control and non-real-time monitoring, respectively. However, in large-scale energy storage cluster applications, existing protocols have the following technical shortcomings: First, the traditional MMS acknowledgment mechanism uses full receipts, resulting in redundancy during batch control and delays often exceeding 1000ms; second, the MMS-TPO transmission window is fixed at 2 frames, leading to extremely low throughput and excessively long total call times; third, GOOSE and MMS use independent timestamp generation mechanisms, resulting in large clock reference deviations, which cannot meet the high-precision time alignment requirements of energy storage system fault recording for event sequences.

[0003] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this application, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0004] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0005] This disclosure provides an optimization method for the communication protocol of an energy storage system based on IEC61850. This method effectively solves the technical problems of high communication latency of control commands, limited total data transmission throughput, and insufficient time alignment accuracy of control and monitoring event sequences in existing large-scale energy storage clusters by selectively acknowledging receipts for the MMS protocol, dynamically and adaptively adjusting the sending window size, and constructing a dual-channel time alignment mechanism based on a unified high-precision clock reference.

[0006] In some embodiments, a method for optimizing the communication protocol of an energy storage system based on IEC61850 is provided, including: An extensible mask field is embedded in the message of the MMS acknowledgment protocol data unit. The preset bits of the extensible mask field correspond one-to-one with each interactive variable in the message, and the state of each bit is used to represent the acknowledgment reception status of the corresponding interactive variable. The interactive variables are divided into key variables and non-key variables according to the importance level of the interactive data. The receiving end parses the extensible mask field and, in combination with the importance level of each interactive variable, generates an immediate individual acknowledgment receipt for key variables and a delayed aggregated receipt for non-key variables. During the communication connection establishment phase, the link round-trip time is measured and the initial transmission window size is negotiated; during the data transmission phase, the dynamic changes of the link round-trip time are monitored at a set period, and when the preset trigger condition is met, the window size renegotiation is initiated. Extend the synchronization timestamp field in the MMS message; obtain a unified clock reference, and generate source timestamps for parallel GOOSE messages and MMS messages based on the clock reference, so that the receiving end can align the control signals and monitoring data on the same time axis.

[0007] In some embodiments, the receiving end parses the expandable mask field and, in conjunction with the importance level of each interaction variable, generates immediate individual confirmation receipts for key variables and delayed aggregated receipts for non-key variables, specifically including: The scalable mask field is embedded in the reserved field of the MMS acknowledgment protocol data unit, and the state of each bit represents the acknowledgment reception state of the corresponding interactive variable. The receiving end identifies the importance level of the interactive variables, generates independent confirmation receipts for key variables and feeds them back first; for non-key variables, they are stored in the aggregated cache area. When the number of temporary storage reaches the preset aggregation threshold or the waiting time of the first variable exceeds the preset timeout threshold, an aggregated confirmation receipt containing the status information of multiple non-key variables is generated and fed back uniformly. After receiving the acknowledgment, the sending end parses the mask field and triggers single-variable priority retransmission for unacknowledged critical variables, and triggers batch retransmission for non-critical variables that have not received acknowledgment within the set timeout period.

[0008] In some embodiments, the step of measuring the link round-trip time and negotiating the initial transmission window size during the communication connection establishment phase includes: Define the window scale type-length-value TLV structure in the extended field of the transmission performance option MMS-TPO; The master station continuously sends test messages to the node energy storage device, records the independent round-trip time and calculates the effective average value as the initial link round-trip time; In some embodiments, the corresponding initial transmission window size is determined by matching the time segment interval in which the initial link round-trip time is located. The master station initiates bidirectional negotiation by sending the TLV structure with the negotiation status bit in the request state, and completes the negotiation of the initial transmission window size after receiving the TLV structure with the negotiation status bit in the acknowledgment state returned by the node energy storage device.

[0009] In some embodiments, the step of monitoring the dynamic changes in link round-trip time at a set period and initiating window-scale renegotiation when a preset trigger condition is met includes: The main station obtains the current real-time sampled link round-trip time according to the polling cycle, and calculates the current smoothed link round-trip time using the exponential smoothing filtering algorithm. The calculation formula is as follows:

[0010] Where RTTcurrent is the smoothed link round-trip time of the current period, RTTsample is the link round-trip time of the current real-time sample, RTTprev is the smoothed link round-trip time of the previous period, and α is the smoothing coefficient used to adjust network sensitivity, and satisfies 0<α<1. Calculate the ratio of the difference between the current smooth link round-trip time and the initial link round-trip time; when it is detected that the ratio of this difference continues to exceed the fluctuation threshold for a set tolerance time, send a window adjustment request message to the corresponding energy storage device to renegotiate the optimal window size after degradation.

[0011] In some embodiments, obtaining a unified clock reference and generating common-source timestamps for parallel GOOSE and MMS messages based on the clock reference includes: The master controller and slave controllers obtain timing signals through a time synchronization interface to maintain a unified clock reference; When assembling a GOOSE message, the sending end obtains the current time from the local clock and writes it into the timestamp field inherent in the GOOSE protocol. When assembling an MMS information report message, the sending end adds the synchronization timestamp field to the optional fields of the message and obtains the current time from the same local clock and writes it into the newly added field. The receiving terminal extracts the time data of the two types of messages respectively, normalizes them into the standard Coordinated Universal Time format based on the clock reference, and splices and reassembles the control events and monitoring events according to the order of timestamps.

[0012] In some embodiments, before classifying the interaction data into critical and non-critical variables based on their importance levels, the method further includes: Real-time acquisition of three-phase power grid physical characteristics and operational data at the grid connection point of the energy storage device, wherein the operational data includes at least the grid frequency change rate and the voltage drop depth at the grid connection point; When the rate of change of the power grid frequency or the voltage drop depth exceeds the corresponding preset threshold, it is determined that a fault has occurred in the external power grid and enters the transient emergency control mode. In the transient emergency control mode, a variable escalation strategy is activated, temporarily elevating the underlying operating environment data and cascade protection early warning status data, which are classified as non-critical variables, to critical variables, and executing immediate individual confirmation receipts and priority retransmission; the escalation strategy is revoked after the operating data returns to a steady state.

[0013] In some embodiments, an energy storage system communication protocol optimization device based on IEC61850 is provided, comprising: The selective receipt processing module is used to embed an extensible mask field in the MMS message, divide the interactive data into key variables and non-key variables according to their importance, execute immediate individual acknowledgment receipts for key variables, and execute delayed aggregate receipts for non-key variables. The dynamic window negotiation module is used to measure the link round-trip time and negotiate the initial transmission window size during the communication connection establishment phase; during the data transmission phase, it monitors the dynamic changes of the link round-trip time and initiates renegotiation when the triggering conditions are met. The dual-channel time alignment module is used to extend the synchronization timestamp field in the MMS message, obtain a unified clock reference, and generate a common timestamp for the GOOSE message and the MMS message so that the receiving end can align the event sequence.

[0014] In some embodiments, an energy storage system communication protocol optimization device based on IEC61850 is provided, including a processor and a memory storing program instructions, wherein the processor is configured to execute an energy storage system communication protocol optimization method based on IEC61850 when running the program instructions.

[0015] On another front, a computer-readable storage medium is provided, storing program instructions that, when executed, perform an optimization method for the communication protocol of an energy storage system based on IEC61850.

[0016] On another front, a computer program product is provided, which, when run by the processor of a computer device, executes an optimization method for the communication protocol of an energy storage system based on IEC61850.

[0017] The energy storage system communication protocol optimization method based on IEC61850 provided in this disclosure can achieve the following technical effects: 1. Reduced control communication latency: By introducing an extensible mask field into the MMS acknowledgment protocol data unit, and using immediate individual acknowledgment receipts for critical variables and delayed aggregated receipts for non-critical variables, redundant acknowledgment interactions in batch write scenarios are reduced; under the test conditions of the embodiments in this specification, the batch write latency is reduced from approximately 1200ms in the traditional solution to approximately 180ms.

[0018] 2. Improve data throughput: By using a dynamic window scale negotiation and renegotiation mechanism based on link round-trip time, the fixed sending window is expanded into a multi-level window that is adaptively adjusted according to link quality, which improves the continuous sending capability of messages while ensuring transmission stability. In the SOE total call scenario of a hundred-unit energy storage cluster in the embodiment of this specification, the total call time is shortened from about 55s to about 9s, and the operation and maintenance efficiency is improved by about 83.6%.

[0019] 3. Improved dual-channel time alignment accuracy: By enabling GOOSE and MMS messages to generate the same source timestamp based on the same clock reference, the receiving end can splice and reassemble control events and monitoring events on a unified time axis; under the test conditions of the embodiments in this specification, the event sequence alignment error is less than 0.1ms, which is about 10 times more accurate than the time deviation of more than 1ms in traditional schemes.

[0020] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0021] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein: Figure 1 This is a flowchart illustrating an overall method for optimizing the communication protocol of an energy storage system based on IEC61850, provided in an embodiment of this disclosure. Figure 2 This is a flowchart of the selective confirmation receipt optimization provided in the embodiments of this disclosure; Figure 3 This is a flowchart of the dynamic window scale negotiation provided in the embodiments of this disclosure; Figure 4 This is a block diagram of the device structure provided in the embodiments of this disclosure; Figure 5 This is a schematic diagram of an electronic device provided in an embodiment of this disclosure.

[0022] Explanation of reference numerals in the attached figures: 100: Selective receipt processing module; 200: Dynamic window negotiation module; 300: Dual-channel time alignment module; 900: Electronic devices; 901: Memory; 902: Communication interface; 903: Bus; 904: Processor. Detailed Implementation

[0023] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure is described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in presentation to simplify the drawings. The terms "first," "second," etc., in the specification, claims, and accompanying drawings of the embodiments of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of the present disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. Unless otherwise stated, the term "a plurality of" means two or more. In the embodiments of this disclosure, the character " / " indicates that the preceding and following objects are in an "or" relationship. For example, A / B means: A or B. The term "and / or" is a descriptive relationship of objects, indicating that three relationships can exist. For example, A and / or B indicates one of three relationships: A or B, or A and B. The term "correspondence" can refer to an association or binding relationship; A corresponding to B means that there is an association or binding relationship between A and B.

[0024] The IEC 61850 protocol, as an international standard in the field of power system automation, has been widely used in smart substations, energy storage power stations, and other scenarios. Its defined GOOSE and MMS protocols handle the transmission of real-time control signals and non-real-time monitoring data, respectively. However, in large-scale energy storage cluster applications, existing communication schemes based on the IEC 61850 protocol suffer from technical drawbacks such as inefficient acknowledgment mechanisms, fixed MMS-TPO windows limiting transmission performance, and insufficient time synchronization accuracy between GOOSE and MMS channels. Traditional MMS confirmed-PDUs use a full acknowledgment mode, typically resulting in batch write latency exceeding 1200ms, which cannot meet the millisecond-level response control requirements of energy storage systems. Furthermore, in SOE total call scenarios for large-scale energy storage clusters with hundreds or more units, data transmission throughput is severely insufficient, with total call times often exceeding 50 seconds. Simultaneously, due to time base discrepancies, the error between GOOSE and MMS is typically greater than 1ms, making it difficult to meet stringent requirements. To address these issues, this application provides a deeply adapted solution.

[0025] Combination Figure 1 As shown, this disclosure provides an optimization method for communication protocols of energy storage systems based on IEC 61850, applicable to a communication network consisting of a communication master station (such as an EMS energy management system) and various levels of energy storage devices (such as a PCS energy storage converter and a BMS battery management system). The method includes the following steps: S1. Optimize the selective acknowledgment mechanism for MMS acknowledgment protocol data units by embedding an extensible mask field in the protocol data unit message; classify each interaction variable into critical variables and non-critical variables according to the importance level of the energy storage system interaction data in cluster collaboration; the receiving end parses the extensible mask field and, in combination with the importance level of each interaction variable, executes an immediate individual acknowledgment strategy for critical variables and a delayed aggregation acknowledgment strategy for non-critical variables.

[0026] like Figure 2 As shown, the selective acknowledgment optimization process includes: the sender embeds an extensible mask field in the MMS acknowledgment protocol data unit and sends the message; the receiver parses the interactive variables and their corresponding mask bit states, and combines the preset importance level classification results to import critical variables into the immediate individual acknowledgment branch and non-critical variables into the aggregation cache branch; when the number of temporary storage in the aggregation cache reaches the preset aggregation threshold, or the waiting time of the first non-critical variable reaches the preset timeout threshold, an aggregation acknowledgment is generated; the sender performs single-variable priority retransmission for unacknowledged critical variables and batch retransmission for unacknowledged non-critical variables based on the mask bit states in the acknowledgment.

[0027] In specific implementation scenarios, this step aims to break the communication congestion caused by the full acknowledgment mode of the traditional MMS confirmed-PDU (Confirmed Protocol Data Unit). In the traditional mode, all variables in the PDU, regardless of their importance, need to be confirmed and acknowledged by the receiving end. This can cause an acknowledgment storm when transmitting batch control commands such as power adjustment and protection policy issuance from multiple PCS.

[0028] Specifically, this embodiment embeds a pre-defined, expandable mask field (MaskField) of a preset width into the ReservedField of the MMSconfirmed-PDU. Considering the scalability of large-scale clusters, this mask field is preferably 32-bit or 64-bit. "1" indicates that the corresponding interactive variable has been successfully received and verified, while "0" indicates that the corresponding variable has not been confirmed or the data packet is corrupted. Based on the operational requirements of the energy storage system, data importance levels are pre-defined at the application layer of the master station and each level of slave station controllers. Interactive data that affects the safe and stable operation of the cluster and requires immediate response is classified as "critical variables," such as PCS power adjustment commands, protection plate activation / deactivation status, and battery overcharge / overdischarge alarm signals. Interactive data that does not affect real-time control and is only used for statistical analysis is classified as "non-critical variables," such as power statistics counters, historical charge / discharge data, and equipment operating temperature trend data. After parsing the PDU message, the receiving end extracts the interactive variables and identifies their corresponding importance levels. For critical variables, the receiving end's communication protocol stack bypasses the conventional waiting queue, immediately generating a separate acknowledgment receipt and prioritizing its insertion into the sending queue before sending it to the master station, ensuring millisecond-level instantaneous response to control commands. For non-critical variables, they are stored in a locally allocated aggregation buffer, employing a delayed aggregation receipt strategy. For example, after accumulating a preset number (preferably 8, dynamically adjustable to 5-10 based on actual link bandwidth) of non-critical variable data, a unified aggregation acknowledgment receipt containing the status of multiple variables is generated. If the waiting time for the first non-critical variable in the buffer exceeds a set timeout threshold (e.g., 1 second), an aggregation receipt is forcibly triggered even if the threshold of 8 has not been reached, to balance transmission reliability and network efficiency. After receiving the receipt information, the sending end accurately determines the acknowledgment status of each variable by parsing the 32-bit or 64-bit mask field. For unacknowledged critical variables with a mask of "0", the sender immediately triggers a high-priority single-variable retransmission command to ensure that critical control signals are not lost or delayed. For non-critical variables, if no acknowledgment is received within the set timeout period, all unacknowledged non-critical variables are retransmitted in batches. Actual testing shows that this selective acknowledgment mechanism reduces batch write latency from 1200ms in the traditional solution to approximately 180ms, significantly improving the synchronization control performance of the energy storage cluster.

[0029] S2. Based on the IEC61850 standard, the transmission performance option MMS-TPO dynamically expands the transmission window size. During the association phase of establishing a communication connection between the master station and the energy storage device, the link round-trip time of the current network is measured, and the initial transmission window size is negotiated based on the link round-trip time. During the data transmission phase, the dynamic changes of the link round-trip time are monitored in real time according to the set monitoring cycle. When the degradation of the link transmission quality is detected to meet the preset trigger conditions, the window size dynamic renegotiation mechanism is initiated to adaptively adjust the message transmission throughput.

[0030] like Figure 3 As shown, the dynamic window scale negotiation process includes: In the association establishment phase, the master station sends a test message to the node energy storage device to obtain the initial link round-trip time, and matches the initial transmission window scale according to the initial link round-trip time; the master station initiates window scale negotiation through a TLV structure carrying the negotiation request status bit, and the slave station returns a TLV structure carrying the negotiation confirmation status bit to complete the confirmation; In the data transmission phase, the master station samples the current link round-trip time at a set period and performs smoothing calculation. When the difference between the smoothed link round-trip time and the initial link round-trip time continuously exceeds the preset fluctuation threshold and reaches the set tolerance time, the window scale renegotiation is triggered.

[0031] This step optimizes the insufficient throughput caused by the default fixed 2-frame window design of MMS-TPO in the IEC61850-8-1 standard. In the scenario of total call for energy storage clusters with hundreds or more units, the fixed 2-frame window requires the transmitter to wait for confirmation of the first two frames before sending subsequent data, which greatly limits the channel utilization.

[0032] To enable dynamic window adjustment, this disclosure defines a dedicated window scale type-length-value (TLV) structure within a reserved field not occupied in the MMS-TPO extended fields. Specifically, the Type field is identified as 0x0A (a dedicated custom identifier); the Length field is fixed at 4 bytes; and the Value field contains three subfields: window scale identifier, multi-level window size options (selectable for 4 / 8 / 16 frames), and a negotiation status bit. The negotiation status bit indicates that the current TLV structure is in the interactive stage of the window scale negotiation process. Preferably, 0x00 represents the negotiation request state, and 0x01 represents the negotiation confirmation state. This design ensures backward compatibility with the existing IEC61850 standard.

[0033] During the Association phase of communication connection establishment, the master station sends three 128-byte test messages to each node, records the round-trip time (RTT) of each frame, and calculates the average value to reduce measurement errors caused by occasional jitter and obtain the initial link RTT. Based on the initial RTT, the master station performs optimal window matching: when RTT ≤ 50ms (excellent link quality), the master station sends a TLV structure with the negotiation status bit in the request state, and the slave station returns a TLV structure with the negotiation status bit in the acknowledgment state to complete the acknowledgment, negotiating the sending window size to 16 frames to maximize throughput; when 50ms < RTT ≤ 100ms (medium link quality), the negotiation window size is 8 frames to balance throughput and stability; when RTT > 100ms (moderate link quality), the negotiation window size is 4 frames to ensure transmission reliability in extreme network environments.

[0034] In actual data transmission, the master station continuously polls the current sampled link round-trip time with a monitoring period of 100ms. To eliminate the interference of transient network jitter on the window adjustment mechanism, this disclosure introduces an exponential smoothing filter algorithm to calculate the current smoothed link round-trip time. The specific calculation formula is as follows:

[0035] Where RTTcurrent is the smoothed link round-trip time for the current period, RTTsample is the link round-trip time sampled in real time, RTTprev is the smoothed link round-trip time for the previous period, and α is the smoothing coefficient used to adjust network sensitivity, satisfying 0 < α < 1.

[0036] This formula allows the system to more smoothly and accurately reflect the true long-term quality trend of the link. The master station calculates the difference between the current smoothed RTT and the initial negotiated RTT in real time. When this difference exceeds a preset fluctuation threshold (preferably 20%), and this threshold exceeds the threshold for a set tolerance time, the master station determines that the network environment has deteriorated, such as LAN congestion or electromagnetic interference. It then immediately sends a window adjustment request message to the corresponding energy storage device to renegotiate the optimal window size after degradation, such as reducing it from 16 frames to 8 frames. Through this dynamic window technology, the total call time of the large-scale energy storage cluster SOE (Sequence of Events) was reduced from 55 seconds to 9 seconds in actual tests, improving the operation and maintenance efficiency by 83.6%.

[0037] S3. Construct a seamless time alignment mechanism for GOOSE and MMS dual channels. Extend the synchronization timestamp field with the same source as the GOOSE protocol in the specified area of ​​the MMS information report message. Obtain a unified clock reference through a high-precision time synchronization network, and generate the same source timestamp for parallel GOOSE messages and MMS messages based on the unified clock reference, so that the receiving end can accurately align and fuse the extracted control signal events and monitoring data events on the same time axis based on the same source timestamp.

[0038] In traditional solutions, GOOSE message timestamps are generated based on the device's local clock, while MMS message timestamps are generated synchronously by the master station clock. Since their time bases are independent, millisecond-level misalignment often occurs between control signals (GOOSE) and monitoring data (MMS) during fault recording and action sequence troubleshooting. This is unacceptable for differential protection and fault location requiring extremely high precision. To achieve nanosecond-level dual-channel alignment, both the master and slave controllers in this embodiment connect to a network conforming to the IEEE 1588-2008 PTP precision clock synchronization protocol via built-in time synchronization modules. The system supports master-slave synchronization mode, is equipped with an independent clock crystal, and has a clock deviation calibration period set to 10ms. The underlying hardware continuously tracks the master clock frequency and performs phase compensation by capturing PTP interaction messages such as Sync, Follow_Up, Delay_Req, and Delay_Resp, ensuring that the clock synchronization accuracy of all nodes within the entire communication network is controlled within ±100ns. During the message assembly phase, when the sending end generates a GOOSE message, it obtains the current absolute time from the high-precision local clock and writes it into the original protocol's inherent time field.

[0039] Meanwhile, in the optional header area of ​​the MMSInformationReport message, the system has added an 8-byte "GOOSE-Timestamp" synchronization timestamp field. This field is forced to use a 1 / 4μs step counter format completely consistent with the GOOSE protocol. When generating an MMS message, the system also reads the timestamp from the same high-precision local clock and writes it to the "GOOSE-Timestamp" field. This same-source writing mechanism ensures that the time difference between the timestamp generation of the two types of messages is ≤0.01ms. This extended field is disabled by default and can be dynamically enabled through master station configuration commands to adapt to specific operation and maintenance debugging scenarios. When the operation and maintenance receiving terminal captures dual-channel messages, it extracts the inherent timestamp of GOOSE and the "GOOSE-Timestamp" field of the MMS message in parallel, converts them uniformly into the standard UTC (Coordinated Universal Time) format, and constructs a unified event sequence table containing action commands and status feedback. This scheme significantly reduces time base deviation, with the final event sequence alignment error being <0.1ms, which is 10 times more accurate than traditional schemes and can meet the needs of high-precision application scenarios in energy storage systems.

[0040] To enhance the communication response survivability of large-scale energy storage clusters under transient grid fault conditions, embodiments of this disclosure also provide an adaptive dynamic cascading adjustment mechanism based on importance level. In some complex application scenarios (such as the Northwest 100 MW-level new energy distribution and storage project), energy storage systems often need to participate in the primary frequency regulation, inertial response, or high and low voltage ride-through of the grid. When a severe grid fault occurs (such as a line short circuit or the disconnection of a large-capacity unit), the instantaneous voltage drop and frequency mutation will generate massive amounts of underlying operating environment data and cascaded protection early warning status data.

[0041] To this end, the communication system collects real-time, high-frequency data on the physical characteristics of the three-phase power grid at the grid connection point of the energy storage device. This includes at least the grid frequency change rate (df / dt), the effective value of the three-phase voltage at the grid connection point (used to calculate the voltage drop depth), and the phase offset. The system has preset frequency emergency change thresholds and high / low voltage ride-through thresholds. When the grid frequency change rate or voltage drop depth exceeds the preset threshold, the master station controller determines that an external power grid fault has occurred, and the energy storage system communication bus is forcibly switched from normal operation mode to transient emergency control mode. In this emergency mode, the master station immediately activates the variable escalation strategy. Data on the underlying operating environment of the energy storage unit (such as cell-level transient current and IGBT junction temperature mutation values) and cascaded protection warning status data, which were originally classified as "non-critical variables" under static configuration (i.e., originally subject to delayed aggregation acknowledgment strategy), are temporarily escalated to "critical variables." This means that during the valuable fault ride-through window, this extended data will be fully applicable to the "instant individual confirmation acknowledgment strategy and single-variable priority retransmission mechanism" in step S1.

[0042] This mechanism ensures that, within the few seconds when the power grid is most vulnerable and fault data is most concentrated, the underlying tracing data can penetrate the communication network and reach the master station in the highest priority and most reliable manner. This helps to avoid the loss of critical fault information caused by the massive amount of stray data washing over the "aggregation waiting buffer" in traditional solutions. Once the three-phase power grid physical characteristic operating data recovers and remains stable within the normal steady-state dead zone for a certain period of time, the system automatically cancels the escalation strategy and resumes normal communication classification, thus achieving a balance between survivability under extreme operating conditions and daily communication efficiency.

[0043] Combination Figure 4 Based on the aforementioned IEC61850 energy storage system communication protocol optimization method, this disclosure provides an IEC61850-based energy storage system communication protocol optimization device, comprising: The selective acknowledgment processing module 100 is used to optimize the selective acknowledgment mechanism for MMS acknowledgment protocol data units. It embeds an extensible mask field in the message to distinguish between critical variables and non-critical variables, and executes differentiated immediate individual acknowledgment or delayed aggregated acknowledgment strategies. The dynamic window negotiation module 200 is used to dynamically expand the transmission window size based on the MMS-TPO transmission performance option of the IEC61850 standard. During the association phase, it calculates the initial window size based on the link round-trip time and monitors the fluctuation of the link round-trip time in real time during the data transmission phase to trigger dynamic renegotiation of the window size. The dual-channel time alignment module 300 is used to construct a seamless time alignment mechanism between GOOSE and MMS. It extends a synchronization timestamp field of the same origin as the GOOSE protocol within a designated area of ​​the MMS information report message, and generates a timestamp of the same origin based on a unified high-precision clock reference for the receiving end to achieve accurate alignment of event sequences. The device provided in this disclosure significantly improves communication real-time performance, data throughput, and time synchronization accuracy through deep coupling optimization of the underlying hardware and software protocols, adapting to the highly dynamic and clustered characteristics of energy storage scenarios. Given that the implementation schemes and methods for solving the problems of the device are similar, the specific implementation methods of the device in the embodiments of this specification can refer to the foregoing method embodiments, and will not be repeated here.

[0044] Combination Figure 5As shown, this disclosure provides an electronic device including a processor 904 and a memory 901. Optionally, the device may further include a communication interface 902 and a bus 903. The processor 904, communication interface 902, and memory 901 can communicate with each other via the bus 903. The communication interface 902 can be used for information transmission. In actual hardware configuration, the electronic device can adopt a distributed master-slave controller architecture. The master controller preferably uses a multi-core processor such as ARM Cortex-A9, with a clock speed of 1GHz or higher, 2GB of memory, and supports multi-threaded parallel processing; the slave controller preferably uses an ARM Cortex-M4 processor, responsible for local PCS / BMS data acquisition and communication execution. The communication interface module includes independent gigabit GOOSE Ethernet interfaces and 100Mbps / gigabit adaptive MMS Ethernet interfaces. The processor 904 can call logical instructions in the memory 901 to execute the communication optimization method of the above embodiments.

[0045] Furthermore, the logic instructions in the aforementioned memory 901 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0046] The memory 901, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor 904 executes functional applications and data processing by running the program instructions / modules stored in the memory 901, thereby implementing the methods in the above embodiments.

[0047] The memory 901 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 901 may include high-speed random access memory and may also include non-volatile memory.

[0048] This disclosure provides a computer program product, which is a software product that mainly implements the methods of this specification through a computer program.

[0049] This disclosure provides a computer-readable storage medium storing computer-executable instructions configured to perform the above-described method.

[0050] The aforementioned computer-readable storage medium is preferably a non-transitory computer-readable storage medium.

[0051] The technical solutions of this disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of this disclosure. The aforementioned storage medium is preferably a non-transitory storage medium, including: a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and other media capable of storing program code.

[0052] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes the element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0053] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0054] The methods and products (including but not limited to devices and equipment) disclosed in the embodiments herein can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units may be merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms. Units described as separate components may or may not be physically separate, and components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to implement this embodiment according to actual needs. Furthermore, the functional units in the embodiments of this disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0055] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks, and the operations or steps corresponding to different blocks in the flowchart and block diagram descriptions, may occur in a different order than indicated in the drawings or descriptions. For example, two consecutive blocks or operation steps may actually be executed substantially in parallel, or sometimes in reverse order, depending on the functions involved. Sometimes there is no specific order between different operations or steps. Each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A method for optimizing the communication protocol of an energy storage system based on IEC61850, characterized in that, include: An extensible mask field is embedded in the message of the MMS acknowledgment protocol data unit. The preset bits of the extensible mask field correspond one-to-one with each interactive variable in the message, and the state of each bit is used to characterize the acknowledgment reception state of the corresponding interactive variable. The interactive variables are divided into critical variables and non-critical variables according to the importance level of the interactive data. The receiving end parses the scalable mask field and, in conjunction with the importance level of each interactive variable, generates an immediate individual confirmation receipt for key variables and a delayed aggregated receipt for non-key variables. During the communication connection establishment phase, the link round-trip time is measured and the initial transmission window size is negotiated; During the data transmission phase, the dynamic changes in the link round-trip time are monitored at a set period. When the preset triggering conditions are met, window scale renegotiation is initiated. Extend the synchronization timestamp field in the MMS message; obtain a unified clock reference, and generate source timestamps for parallel GOOSE messages and MMS messages based on the clock reference, so that the receiving end can align the control signals and monitoring data on the same time axis.

2. The method according to claim 1, characterized in that, The receiving end parses the expandable mask field and, based on the importance level of each interaction variable, generates immediate individual confirmation receipts for key variables and delayed aggregated receipts for non-key variables. Specifically, this includes: The scalable mask field is embedded in the reserved field of the MMS acknowledgment protocol data unit, and the state of each bit represents the acknowledgment reception state of the corresponding interactive variable. The receiving end identifies the importance level of the interactive variables, generates independent confirmation receipts for key variables and feeds them back first; for non-key variables, they are stored in the aggregated cache area. When the number of temporary storage reaches the preset aggregation threshold or the waiting time of the first variable exceeds the preset timeout threshold, an aggregated confirmation receipt containing the status information of multiple non-key variables is generated and fed back uniformly. After receiving the acknowledgment, the sending end parses the mask field and triggers single-variable priority retransmission for unacknowledged critical variables, and triggers batch retransmission for non-critical variables that have not received acknowledgment within the set timeout period.

3. The method according to claim 1, characterized in that, The process of measuring link round-trip time and negotiating initial transmission window size during the communication connection establishment phase includes: Define the window scale type-length-value TLV structure in the extended field of the transmission performance option MMS-TPO; The master station continuously sends test messages to the node energy storage device, records the independent round-trip time and calculates the effective average value as the initial link round-trip time; Based on the time segment interval in which the initial link round-trip time is located, the corresponding initial transmission window size is determined. The master station initiates bidirectional negotiation by sending the TLV structure with the negotiation status bit in the request state, and completes the negotiation of the initial transmission window size after receiving the TLV structure with the negotiation status bit in the acknowledgment state returned by the node energy storage device.

4. The method according to claim 3, characterized in that, The process of monitoring the dynamic changes in link round-trip time at a set period, and initiating window-scale renegotiation when a preset trigger condition is met, includes: The main station obtains the current real-time sampled link round-trip time according to the polling cycle, and calculates the current smoothed link round-trip time using the exponential smoothing filtering algorithm. The calculation formula is as follows: Where RTTcurrent is the smoothed link round-trip time of the current period, RTTsample is the link round-trip time of the current real-time sample, RTTprev is the smoothed link round-trip time of the previous period, and α is the smoothing coefficient used to adjust network sensitivity, and satisfies 0<α<1. Calculate the ratio of the difference between the current smooth link round-trip time and the initial link round-trip time; when it is detected that the ratio of this difference continues to exceed the fluctuation threshold for a set tolerance time, send a window adjustment request message to the corresponding energy storage device to renegotiate the optimal window size after degradation.

5. The method according to claim 1, characterized in that, The step of obtaining a unified clock reference and generating common-source timestamps for parallel GOOSE and MMS messages based on the clock reference includes: The master controller and slave controllers obtain timing signals through a time synchronization interface to maintain a unified clock reference; When assembling a GOOSE message, the sending end obtains the current time from the local clock and writes it into the timestamp field inherent in the GOOSE protocol. When assembling an MMS information report message, the sending end adds the synchronization timestamp field to the optional fields of the message and obtains the current time from the same local clock and writes it into the newly added field. The receiving terminal extracts the time data of the two types of messages respectively, normalizes them into the standard Coordinated Universal Time format based on the clock reference, and splices and reassembles the control events and monitoring events according to the order of timestamps.

6. The method according to claim 1, characterized in that, Before categorizing interactive data into critical and non-critical variables based on their importance level, the following steps are also included: Real-time acquisition of three-phase power grid physical characteristics and operational data at the grid connection point of the energy storage device, wherein the operational data includes at least the grid frequency change rate and the voltage drop depth at the grid connection point; When the rate of change of the power grid frequency or the voltage drop depth exceeds the corresponding preset threshold, it is determined that a fault has occurred in the external power grid and enters the transient emergency control mode. In the transient emergency control mode, a variable escalation strategy is activated, temporarily elevating the underlying operating environment data and cascade protection early warning status data, which are classified as non-critical variables, to critical variables, and executing immediate individual confirmation receipts and priority retransmission; the escalation strategy is revoked after the operating data returns to a steady state.

7. A communication protocol optimization device for energy storage systems based on IEC61850, characterized in that, include: The selective receipt processing module is used to embed an extensible mask field in the MMS message, divide the interactive data into key variables and non-key variables according to their importance, execute immediate individual acknowledgment receipts for key variables, and execute delayed aggregate receipts for non-key variables. The dynamic window negotiation module is used to measure the link round-trip time and negotiate the initial transmission window size during the communication connection establishment phase; during the data transmission phase, it monitors the dynamic changes of the link round-trip time and initiates renegotiation when the triggering conditions are met. The dual-channel time alignment module is used to extend the synchronization timestamp field in the MMS message, obtain a unified clock reference, and generate a common timestamp for the GOOSE message and the MMS message so that the receiving end can align the event sequence.

8. A communication protocol optimization device for energy storage systems based on IEC61850, characterized in that, It includes a processor and a memory storing program instructions, the processor being configured to, when executing the program instructions, perform the energy storage system communication protocol optimization method based on IEC61850 as described in any one of claims 1 to 6.

9. A computer-readable storage medium storing program instructions, characterized in that, When the program instructions are executed, they perform the energy storage system communication protocol optimization method based on IEC61850 as described in any one of claims 1 to 6.

10. A computer program product, characterized in that, When the computer program product is run by the processor of the computer device, it executes the energy storage system communication protocol optimization method based on IEC61850 as described in any one of claims 1 to 6.

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