A WiFi-based switching power supply collaborative control system

Abstract

This invention belongs to the field of wireless local area network (WLAN) connection management technology, specifically relating to a switching power supply collaborative control system based on WiFi communication. The system includes a wireless access point and multiple switching power supplies. The access point is divided into multiple basic service set identifiers and assigned independent coloring values, and the switching power supplies are assigned to the corresponding identifiers according to the master-slave hierarchy. The access point monitors the coloring values ​​in the physical layer preamble to identify co-channel interference, triggers the reconfiguration of the enhanced distributed channel access mechanism, sets the minimum arbitration inter-frame interval of the access category carrying the master-level collaborative control message to zero, and fixes the contention window parameters. When the minimum arbitration inter-frame interval is met, the switching power supply sends a message carrying a master-slave synchronization timing tag. The slave power supply adjusts the switching transistor conduction timing according to the tag to achieve phase locking. This invention blocks air interface preemption of control messages by co-channel devices, eliminates random backoff delay jitter in the access channel, and solves the problem of control message delay and packet loss caused by co-channel interference.

Description

Technical Field

[0001] This invention belongs to the field of wireless local area network connection management technology, specifically relating to a switching power supply collaborative control system based on WiFi communication. Background Technology

[0002] In existing wireless LAN-based switching power supply collaborative control systems, multiple switching power supplies in a master-slave hierarchy are typically connected to the same wireless access point and share a single communication channel. In this architecture, message interaction between the wireless access point and each switching power supply relies on a carrier sense multiple access (CSM) collision avoidance mechanism. When a switching power supply needs to send a master-slave synchronization control message, its wireless communication station continuously monitors the channel status at the physical layer. If the channel is detected as occupied, a backoff value is randomly selected within the contention window according to the backoff algorithm, and the power supply waits. Only when the channel remains idle for a period equal to the distributed coordination function inter-frame interval can the switching power supply compete for the right to transmit the channel and send a control message containing synchronization timing information to the slave switching power supply. The slave switching power supply then adjusts the turn-on timing of its local switching transistors based on this message to achieve phase-locked operation with the master switching power supply.

[0003] In industrial applications, numerous other wireless LAN devices operating on the same frequency band are typically present in the environment. When signals from these co-channel interfering devices are received by the physical layer of the switching power supply's wireless communication station, the carrier sense multiple access (CMA) collision avoidance mechanism will classify it as a busy channel. Because current technologies allow all switching power supplies to share a single communication channel and lack differentiated channel allocation strategies for control messages at different levels, co-channel interference signals directly block the normal transmission of master-slave synchronization control messages. This leads to unpredictable queuing delays and packet loss in the control messages, causing the slave-level switching power supply to fail to receive synchronization commands on time, resulting in a loss of synchronization between the master and slave power supply turn-on timings. Summary of the Invention

[0004] The purpose of this invention is to provide a WiFi-based switching power supply collaborative control system, which can solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A WiFi-based switching power supply collaborative control system includes a WiFi access point and multiple switching power supplies connected to the WiFi access point via a WiFi network. The WiFi access point divides multiple basic service set identifiers and assigns an independent BSS coloring value to each basic service set identifier. The WiFi access point assigns the switching power supplies at different master-slave levels to the corresponding basic service set identifiers. The WiFi access point monitors the BSS coloring value in the air interface physical layer preamble. When it identifies a co-channel interference signal with a different BSS coloring value than its own system, it triggers an enhanced distributed channel access mechanism reconfiguration. It assigns a preset minimum arbitration inter-frame interval and contention window parameters to the access category carrying the master-level switching power supply collaborative control message. When the WiFi station in the switching power supply detects that the channel is idle and meets the minimum arbitration inter-frame interval, it sends a collaborative control message carrying a master-slave synchronization timing tag. The slave-level switching power supply adjusts the conduction timing of its local switching transistors according to the received master-slave synchronization timing tag to achieve phase-locked operation with the master-level switching power supply.

[0006] Preferably, the WiFi access point's division of multiple basic service set identifiers and allocation of an independent BSS coloring value to each basic service set identifier includes: the WiFi access point pre-stores a master-slave hierarchy mapping table for the switching power supply; when the WiFi access point receives an association request frame sent by the switching power supply, it parses the power topology identity field carried in the association request frame; the WiFi access point queries the master-slave hierarchy mapping table based on the power topology identity field to determine the master-slave hierarchy position of the switching power supply; the WiFi access point generates a specific basic service set identifier corresponding to the master-slave hierarchy position; simultaneously, it calls a random number generator to generate a BSS coloring value bound to the specific basic service set identifier; and writes the BSS coloring value into the physical layer aggregation process sub-layer header of the beacon frame and broadcasts it outward.

[0007] Preferably, the monitoring of the BSS coloring value in the air interface physical layer preamble by the WiFi access point includes: the physical layer chip of the WiFi access point continuously demodulates the received radio frequency signal, extracts the signaling field in the physical layer preamble, extracts a preset length of BSS coloring bits from the signaling field, converts the BSS coloring bits into decimal values, performs a matching operation on the decimal values ​​with the locally stored set of valid BSS coloring values, and when the result of the matching operation is a mismatch, records the decimal value corresponding to the mismatch and the receiving timestamp, and reports the interference characteristics containing the decimal value to the MAC layer of the WiFi access point.

[0008] Preferably, the triggering of the enhanced distributed channel access mechanism reconfiguration includes: after the MAC layer of the WiFi access point receives interference features that are not the BSS coloring value of the local system, it searches the current enhanced distributed channel access parameter table, modifies the arbitration inter-frame interval value of the access category of the corresponding cooperative control message in the enhanced distributed channel access parameter table to zero, and sets the minimum and maximum contention window values ​​of the access category to preset fixed values. The WiFi access point generates an action management frame carrying the modified parameters and sends the action management frame to all the switching power supplies in the associated state.

[0009] Preferably, the sending of the cooperative control message carrying the master-slave synchronization timing tag includes: when the WiFi station of the master-level switching power supply detects that the duration of the channel idle state has reached the minimum arbitration inter-frame interval, the current phase value output by the local phase-locked loop circuit is encapsulated into the frame body field of the WiFi data frame to form the master-slave synchronization timing tag, a type identifier is added before the frame body field, the WiFi station encapsulates the data frame with the type identifier and the master-slave synchronization timing tag into a MAC layer header and a physical layer header, and sends the encapsulated data frame to the air interface through the antenna.

[0010] Preferably, the slave-level switching power supply adjusts the conduction timing of its local switching transistors based on the received master-slave synchronization timing tag, including: after receiving the cooperative control message, the WiFi station of the slave-level switching power supply strips the MAC layer header and physical layer header of the cooperative control message, extracts the current phase value from the frame body field, the master control chip of the slave-level switching power supply uses the current phase value as a reference phase input to the phase comparator of the local digital phase-locked loop, the phase comparator calculates the phase difference between the reference phase and the local sampled phase, converts the phase difference into a phase shift compensation amount of the pulse width modulation signal, and superimposes the phase shift compensation amount onto the original carrier phase of the pulse width modulation signal.

[0011] Preferably, the power topology identity field is generated through the following steps: after the switching power supply is powered on, it identifies its own master-slave physical topology position through the hardware pin level status; the main control chip of the switching power supply reads the hardware pin level status and queries the locally stored level-identity mapping table to generate the power topology identity field containing the hierarchical code and serial number; the switching power supply fills the power topology identity field into the vendor-specific information element of the probe request frame; after completing the association of the specific basic service set identifier, the switching power supply writes the power topology identity field and the allocated BSS coloring value into non-volatile memory to form a binding relationship table.

[0012] Preferably, the step of reporting the interference features containing the decimal value to the MAC layer of the WiFi access point includes: the physical layer of the WiFi access point cumulatively records the number of times a received decimal value that does not match the set of valid BSS coloring values ​​within a preset statistical time window; when the number exceeds a preset interference threshold, the physical layer generates an interference statistical vector containing the decimal value, the number, and the statistical time window, and sends the interference statistical vector to the enhanced distributed channel access control module of the MAC layer through the service access point primitive between the physical layer and the MAC layer.

[0013] Preferably, after the action management frame is sent to all the power supplies in the associated state, the following steps are further performed: the MAC layer of the WiFi access point starts an interference cancellation timer. During the timing of the interference cancellation timer, the WiFi access point continuously monitors the BSS coloring value in the air interface physical layer preamble. When no co-channel interference signal with a BSS coloring value other than that of the system is detected within multiple consecutive beacon intervals, the MAC layer of the WiFi access point generates an action management frame to restore the default parameters, and sends the action management frame to restore the default parameters to the power supply to restore the arbitration inter-frame interval value and contention window value of the access category.

[0014] Preferably, before encapsulating the current phase value output by the local phase-locked loop circuit into the frame body field of the WiFi data frame to form the master-slave synchronization timing tag, the following steps are performed: the master-level switching power supply reads the count value of the local real-time clock counter, performs a difference calculation between the count value and the receiving timestamp when the beacon frame sent by the WiFi access point is received, obtains the clock drift offset, the master-level switching power supply performs a concatenation calculation between the clock drift offset and the current phase value, encapsulates the concatenated data packet as the new master-slave synchronization timing tag into the frame body field, and adds a cyclic redundancy check code to the end of the frame body field.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention constructs a hierarchical communication subnet by dividing the network into multiple basic service set identifiers and assigning independent basic service set coloring values, and allocating switching power supplies to the corresponding basic service set identifiers according to their master-slave hierarchical positions. By monitoring the basic service set coloring values ​​in the physical layer preamble, it identifies co-channel interference signals not originating from the local system. Upon interference detection, it triggers a reconfiguration of the enhanced distributed channel access mechanism, setting the minimum arbitration inter-frame interval for the access category carrying the master-level switching power supply's collaborative control messages to zero and fixing the contention window parameters. These measures prevent other wireless devices in the same frequency band from preempting the air interface of the collaborative control messages, eliminate random backoff delay jitter caused by control messages when accessing the channel, and solve the problems of control message queuing delay and packet loss caused by co-channel interference.

[0016] 2. By parsing the power topology identity field in the association request frame and combining it with the master-slave hierarchy mapping table to determine the power level, the generated specific basic service set identifier and basic service set coloring value are written into the beacon frame, realizing the automatic binding of the communication subnet and physical topology. By counting the number of mismatched coloring values ​​at the physical layer and generating an interference statistics vector to report to the media access control layer when the interference threshold is exceeded, and by setting an interference cancellation timer to send an action management frame to restore default parameters after the interference disappears, dynamic adaptive adjustment of enhanced distributed channel access parameters is achieved. By splicing the real-time clock drift offset and the current phase value in the cooperative control message and adding a cyclic redundancy check code, clock deviations during message transmission are corrected, ensuring the conduction timing synchronization accuracy of the master-slave level switching power supply in a strong electromagnetic noise environment and reducing the risk of short circuits caused by timing misalignments. Attached Figure Description

[0017] Figure 1 A flowchart illustrating the overall operation of a WiFi-based switching power supply collaborative control system provided in this embodiment of the invention. Figure 2 This is a flowchart illustrating the automatic binding process between the communication subnet and the physical topology of the switching power supply, as provided in an embodiment of the present invention. Figure 3 This is a flowchart of co-channel interference detection and enhanced distributed channel access parameter reconfiguration provided in an embodiment of the present invention; Figure 4 A flowchart of the encapsulation and transmission process of the main-level switching power supply collaborative control message provided in an embodiment of the present invention; Figure 5 A flowchart of the slave-level switching power supply turn-on timing phase-locked loop adjustment provided in an embodiment of the present invention; Figure 6 The flowchart illustrates the automatic recovery process of enhanced distributed channel access parameters after interference cancellation, as provided in this embodiment of the invention. Detailed Implementation

[0018] refer to Figure 1In this embodiment, the WiFi-based switching power supply collaborative control system includes a WiFi access point and multiple switching power supplies connected to the WiFi access point via a WiFi network. Both the WiFi access point and the switching power supplies support the IEEE 802.11ax protocol specification. The WiFi access point has media access control layer and physical layer processing capabilities. The switching power supply has a built-in WiFi station module, a main control chip, a digital phase-locked loop circuit, a switching transistor drive circuit, and a power conversion main circuit. The WiFi station module and the main control chip establish a communication connection through a serial peripheral interface bus. The pulse width modulation output terminal of the main control chip is electrically connected to the input terminal of the switching transistor drive circuit, and the output terminal of the switching transistor drive circuit is electrically connected to the gate of the switching transistor in the power conversion main circuit.

[0019] In one embodiment, after the WiFi access point completes power-on initialization, it divides multiple basic service set identifiers at the MAC layer and assigns an independent BSS coloring value to each basic service set identifier. The BSS coloring value is a 6-bit unsigned integer conforming to the IEEE 802.11ax protocol specification. The BSS coloring values ​​corresponding to each basic service set identifier do not overlap and have no intersection with the pre-stored set of occupied BSS coloring values ​​in the surrounding area. Based on the master-slave topology of the switching power supply, the WiFi access point assigns switching power supplies at different positions in the master-slave layer to the corresponding basic service set identifiers, constructing a hierarchical communication subnet corresponding to the master-slave topology. Switching power supplies at the same master-slave layer access the communication subnet corresponding to the same basic service set identifier and share the BSS coloring value and channel access parameters corresponding to that subnet. The physical layer of the WiFi access point continuously monitors the air interface radio frequency signal, extracts the BSS coloring value from the physical layer preamble of the received signal, and completes the parsing and matching processing of the BSS coloring value. When a co-channel interference signal with a different BSS coloring value than that of the system is identified, the interference feature is reported to the MAC layer, triggering the MAC layer to execute the enhanced distributed channel access mechanism reconfiguration. After receiving interference characteristics, the MAC layer of the WiFi access point looks up the enhanced distributed channel access parameter table stored locally. It then assigns a preset minimum arbitration inter-frame interval and contention window parameters to the access category carrying the master-level switching power supply's collaborative control message. After parameter reconfiguration, the WiFi access point generates a management frame carrying the reconfigured parameters and sends it to all associated switching power supplies. Upon receiving the reconfigured parameters, the WiFi stations in the switching power supplies update their local channel access configuration. When the local physical layer detects that the channel is idle and the idle duration meets the minimum arbitration inter-frame interval, it acquires the master-slave synchronization timing information and encapsulates it into a collaborative control message. This message, carrying a master-slave synchronization timing tag, is sent over the air interface. Upon receiving the collaborative control message, the WiFi stations in the slave-level switching power supplies parse and verify the message, extract the master-slave synchronization timing tag, input the phase information corresponding to the timing tag into the local control link, and adjust the conduction timing of their local switching transistors according to the master-slave synchronization timing tag. This ensures that the conduction phase of the local switching transistors is consistent with the conduction phase of the master-level switching power supply, achieving phase-locked operation of the master-slave switching power supplies.

[0020] Table 1. Correspondence between Basic Service Set Identifier, Master-Slave Hierarchy, and BSS Coloring Value in this Embodiment Table 1 is used to clarify the configuration correspondence of the hierarchical communication subnet in this embodiment. By binding the basic service set identifier with the master-slave level, the communication resources of the switching power supply at different levels are isolated, avoiding channel resource competition of control messages at different levels. At the same time, the independent BSS coloring value enables accurate identification and filtering of co-channel interference.

[0021] This embodiment fully implements the basic operation process of the system. Through hierarchical basic service set identifier division and BSS coloring value allocation, a communication subnet architecture matching the physical topology is constructed. Through physical layer BSS coloring value monitoring, rapid identification of non-system co-channel interference is achieved. Through interference-triggered enhanced distributed channel access mechanism reconfiguration, the channel access priority of the master-level switching power supply collaborative control message is guaranteed, eliminating random delay and packet loss of control message channel access caused by co-channel interference. Through master-slave synchronization timing tags in the collaborative control message, the conduction timing synchronization of the master and slave switching power supplies is achieved, completing the core function of phase-locked operation.

[0022] refer to Figure 2 In a preferred embodiment, the WiFi access point pre-stores a master-slave hierarchy mapping table for the switching power supply during the initialization phase. This table stores the corresponding relationships between hierarchy codes, master-slave hierarchy attributes, basic service set identifier allocation rules, and BSS coloring value ranges. When the WiFi access point receives an association request frame from the switching power supply, it parses the frame body field of the association request frame and extracts the power supply topology identity field carried in the frame. This power supply topology identity field contains the switching power supply's hierarchy code and unique device identifier information. The WiFi access point queries the pre-stored master-slave hierarchy mapping table based on the extracted hierarchy code to match the master-slave hierarchy position corresponding to the switching power supply. Based on the allocation rules in the master-slave hierarchy mapping table, it generates a specific basic service set identifier corresponding to this master-slave hierarchy position. Simultaneously, it calls a local random number generator to generate a BSS coloring value bound to the specific basic service set identifier. The BSS coloring value generated by the random number generator is within the value range corresponding to this master-slave hierarchy and is not occupied by other basic service set identifiers in the system. After the WiFi access point completes the binding of the Basic Service Set Identifier and the BSS coloring value, it writes the bound BSS coloring value into the corresponding signaling field of the physical layer aggregation process sub-layer header of the beacon frame, and broadcasts the beacon frame outward according to the preset beacon interval, so that the corresponding layer of switching power supply can receive and parse the configuration information in the beacon frame.

[0023] Furthermore, during the power-on initialization phase, the switching power supply generates its own power topology identity field. After power-on, the switching power supply identifies its physical location in the master-slave topology through the hardware pin level states. The master control chip reads the combination of hardware pin level states, queries the locally stored level-identity mapping table, matches the corresponding level code, and combines it with the unique device serial number pre-stored on the device to generate a power topology identity field containing the level code and serial number. After generating the power topology identity field, the switching power supply fills this field into the vendor-specific information element of the probe request frame and sends probe request frames to surrounding WiFi access points. Upon receiving a probe response frame from a WiFi access point with a corresponding specific basic service set identifier, the switching power supply sends an association request frame to that specific basic service set identifier, completing the association process with the corresponding communication subnet. After the switching power supply completes the association of a specific basic service set identifier, it writes the local power topology identity field, the allocated BSS coloring value, and the basic service set identifier into the local non-volatile memory to form a binding relationship table. The binding relationship table is stored after the switching power supply is powered off. When the switching power supply is powered on again, it can directly read the binding relationship table and initiate the association process to the corresponding basic service set identifier without repeating the topology identity recognition and configuration information acquisition process.

[0024] In this embodiment, the random number generator uses a linear congruential generation algorithm, and the corresponding mathematical expression is: in, The random sequence value output by the random number generator. The preset multiplier coefficient, The preset increment coefficient, The generated random sequence value is mapped to a 6-bit BSS coloring value after modulo operation, with the value range being a preset legal interval.

[0025] Table 2. Mapping Relationship between Hardware Level States and Hierarchical Codes and Master-Slave Hierarchy in this Embodiment Table 2 defines the hardware identification rules for the switching power supply topology. By mapping the hardware pin level combinations to the hierarchical codes, the master-slave hierarchical position of the switching power supply is automatically identified without the need for manual configuration of hierarchical information, thus improving the convenience of system deployment and the flexibility of topology adaptation.

[0026] This embodiment refines the allocation process of basic service set identifiers and BSS coloring values. It realizes the automatic generation of switching power supply topology identity through hardware pin level identification and mapping table matching. It realizes the automatic binding of communication subnet and physical topology through parsing of association request frames and master-slave hierarchy mapping table query. It simplifies the association process of repeated power-on by storing the binding relationship table in non-volatile memory, and realizes the adaptive configuration and rapid deployment of system topology.

[0027] refer to Figure 3 In a preferred embodiment, the physical layer chip of the WiFi access point continuously performs down-conversion, analog-to-digital conversion, and orthogonal frequency division multiplexing demodulation processing on the received air interface radio frequency signal. It extracts the signaling field from the physical layer preamble, truncates a preset length of BSS coloring bits from the signaling field, and converts the truncated BSS coloring bits into decimal values ​​according to a preset bit order. The physical layer of the WiFi access point performs a matching operation with a locally stored set of valid BSS coloring values. When the matching operation results in a mismatch, the received signal is determined to be a non-local co-channel interference signal. The physical layer records the decimal value corresponding to the mismatch and the reception timestamp, where the reception timestamp is the local clock count value corresponding to the moment the physical layer completes preamble demodulation.

[0028] Furthermore, within a preset statistical time window, the physical layer of the WiFi access point accumulates the number of occurrences of received decimal values ​​that do not match the set of valid BSS coloring values. When the accumulated number exceeds a preset interference threshold, the physical layer generates an interference statistical vector containing the decimal value, the accumulated number, and the statistical time window information. This interference statistical vector is then sent to the enhanced distributed channel access control module of the MAC layer via the service access point primitive between the physical layer and the MAC layer. Upon receiving the interference statistical vector corresponding to a BSS coloring value other than that of the local system, the MAC layer of the WiFi access point searches the currently stored enhanced distributed channel access parameter table. This table stores the arbitration inter-frame interval, minimum contention window value, maximum contention window value, and transmission opportunity limitation parameters corresponding to different access categories. The MAC layer modifies the arbitration inter-frame interval value of the access category corresponding to the cooperative control message in the enhanced distributed channel access parameter table to zero, and simultaneously sets the minimum and maximum contention window values ​​of that access category to preset fixed values, thus completing the reconfiguration of the enhanced distributed channel access parameters. The WiFi access point generates an action management frame carrying the modified parameters and broadcasts the action management frame to all associated power supplies. After receiving the action management frame, the power supply parses and updates the locally stored enhanced distributed channel access parameter table. Subsequent channel access processes are executed using the updated parameters.

[0029] refer to Figure 6 Furthermore, while sending an action management frame carrying the reconfigured parameters, the MAC layer of the WiFi access point starts an interference cancellation timer. During the timing of the interference cancellation timer, the physical layer of the WiFi access point continuously monitors the BSS coloring value in the air interface physical layer preamble. When no co-channel interference signal with a BSS coloring value other than that of this system is detected within multiple consecutive beacon intervals, the MAC layer of the WiFi access point generates an action management frame to restore the default parameters and sends the action management frame to all associated switching power supplies. After receiving the action management frame, the switching power supply restores the local enhanced distributed channel access parameter table to the default configuration and executes the normal channel access procedure.

[0030] In this embodiment, the formula for calculating the bit order conversion of the BSS coloring value is: in, Color the converted decimal BSS values. The preset BSS coloring bit length, The value of the i-th bit in the extracted BSS coloring bits is either 0 or 1.

[0031] In this embodiment, the formula for matching BSS coloring values ​​is: in, To match the results of the operation, This is the set of legal BSS coloring values ​​stored locally in this system. A matching result of 1 indicates a successful match, and a matching result of 0 indicates a failed match.

[0032] In this embodiment, the formula for calculating the duration of the arbitration inter-frame interval is as follows: in, The duration of the arbitration inter-frame interval. The short inter-frame interval as specified in the protocol. This represents the number of arbitration frame intervals. The duration of the time slot as specified in the agreement.

[0033] The formula for calculating the retreat time in this embodiment is: in, To avoid the length of time, From 0 to the competition window size A random integer between [a certain value], when the minimum and maximum values ​​of the competition window are set to the same fixed value, the competition window size [is determined]. The backoff time is a fixed value, eliminating the delay jitter caused by random backoff.

[0034] Table 3 Comparison of Default Configuration and Interference Triggered Reconfiguration of Enhanced Distributed Channel Access Parameters in This Embodiment Table 3 is used to clarify the changes in channel access parameters for each access category before and after interference is triggered. By setting the number of arbitration inter-frame intervals for the corresponding access category of the cooperative control message to zero and setting the contention window to a fixed value, the highest channel access priority of the cooperative control message in the same-frequency interference environment is guaranteed, and random delay of channel access is eliminated.

[0035] This embodiment refines the detection, reporting, and processing procedures for co-channel interference. By extracting and matching BSS coloring bits at the physical layer, it achieves accurate identification of co-channel interference from other systems. By accumulating interference occurrences within a statistical time window and using threshold judgment, it achieves reliable triggering of interference events. By reconfiguring the enhanced distributed channel access parameters triggered by interference, it achieves dynamic improvement of the channel access priority of the cooperative control message. By using an interference cancellation timer and continuous interference monitoring, it achieves automatic recovery of channel access parameters after the interference disappears, balancing the system's anti-interference capability with the fair use of channel resources.

[0036] refer to Figure 4 In a preferred embodiment, after receiving the reconfigured enhanced distributed channel access parameters from the WiFi access point, the WiFi station of the main-level switching power supply updates its local channel access configuration. The physical layer continuously performs idle channel evaluation operations and monitors the occupancy status of the air interface channel in real time. When the physical layer detects that the channel is idle and the duration of the idle state reaches the minimum arbitration inter-frame interval after reconfiguration, it sends a channel availability indication to the main control chip. After receiving the channel availability indication, the main control chip reads the current phase value output by the local digital phase-locked loop circuit and prepares for the encapsulation and transmission of the cooperative control message.

[0037] Furthermore, before encapsulating the current phase value output by the local phase-locked loop circuit into the frame body field of the WiFi data frame, the main-stage switching power supply reads the current count value of the local real-time clock counter, calculates the difference between this count value and the timestamp of the most recent beacon frame received from the WiFi access point, and obtains the clock drift offset. The main-stage switching power supply concatenates the calculated clock drift offset with the current phase value, encapsulates the concatenated data packet as a new master-slave synchronization timing tag into the frame body field of the WiFi data frame, adds a type identifier to the beginning of the frame body field to identify the cooperative control message, and adds a cyclic redundancy check (CRC) code to the end of the frame body field to verify the transmission integrity of the frame body data. The WiFi station encapsulates the data frame with the type identifier, master-slave synchronization timing tag, and CRC code into a MAC layer header and a physical layer header, fills the physical layer header with the BSS coloring value of the corresponding communication subnet, and transmits the encapsulated data frame to the air interface through the RF antenna.

[0038] refer to Figure 5 Furthermore, after receiving the cooperative control message from the WiFi station of the primary switching power supply, the message is demodulated at the physical layer and parsed at the MAC layer. The MAC layer header and physical layer header of the cooperative control message are stripped off, and the frame body field is extracted. First, it is verified whether the type identifier at the beginning of the frame body field matches the preset cooperative control message identifier. If the match is successful, the frame body field is subjected to cyclic redundancy check. If the check is successful, the master-slave synchronization timing tag in the frame body field is extracted, and the clock drift offset and the current phase value of the primary switching power supply are obtained. The master control chip of the slave-level switching power supply corrects the current phase value based on the clock drift offset to obtain the corrected reference phase. The reference phase is then input to the phase comparator of the local digital phase-locked loop. The phase comparator calculates the phase difference between the reference phase and the local sampled phase. After periodically correcting the phase difference, it is input to the loop filter. The loop filter outputs the phase shift compensation amount of the pulse width modulation signal. The master control chip superimposes the phase shift compensation amount onto the original carrier phase of the pulse width modulation signal to generate the adjusted pulse width modulation signal. This adjusted signal is then output to the switching transistor drive circuit. The switching transistor drive circuit adjusts the conduction timing of the local switching transistor to ensure that the conduction phase of the local switching transistor is consistent with the conduction phase of the master-level switching power supply, thus achieving phase-locked operation.

[0039] In this embodiment, the formula for calculating the clock drift offset is: in, This is the clock drift offset. This is the current count value of the real-time clock counter. The timestamp of the most recent beacon frame received. This is the nominal transmission interval for beacon frames.

[0040] The formula for calculating the correction of the reference phase in this embodiment is as follows: in, This is the corrected reference phase. The current phase value of the main stage switching power supply. The carrier period of the pulse width modulation signal.

[0041] In this embodiment, the formulas for calculating the phase difference and correcting the period are as follows: in, For phase difference, For the local sampling phase of the slave-level switching power supply, This is a sign function that outputs 1 when the input value is greater than 0, -1 when it is less than 0, and 0 when it is equal to 0.

[0042] In this embodiment, the loop filter uses a proportional-integral control algorithm, and the corresponding formula for calculating the phase shift angle compensation is as follows: in, This is the phase shift angle compensation amount. This is a preset proportional coefficient. The preset integral coefficient, The phase difference obtained from the nth sampling is... This represents the cumulative number of samples taken.

[0043] The formula for calculating the carrier phase adjustment in this embodiment is: in, The adjusted carrier phase, This represents the original carrier phase of the pulse width modulation signal.

[0044] Table 4. Field structure table of master-slave synchronization time sequence tag in this embodiment. Table 4 is used to clarify the field structure and physical meaning of the master-slave synchronization timing tag in the collaborative control message. Through standardized field encapsulation, reliable transmission and parsing of timing information and clock drift correction information between the master and slave switching power supplies are ensured.

[0045] This embodiment refines the generation, encapsulation, transmission, and parsing process of collaborative control messages. By splicing clock drift offsets into the master-slave synchronization timing tags, it corrects the phase error caused by clock deviation between the master and slave switching power supplies and message transmission delay. Cyclic redundancy check codes ensure the integrity of timing information transmission. Through phase comparison, loop filtering, and phase adjustment of digital phase-locked loops, it achieves precise synchronization of the switching transistor turn-on timing of the master and slave switching power supplies, reduces the risk of circuit failures caused by timing misalignment, and improves the system's operational stability in complex electromagnetic environments.

Claims

1. A switching power supply collaborative control system based on WiFi communication, characterized in that, The system includes a WiFi access point and multiple switching power supplies connected to the WiFi access point via a WiFi network. The WiFi access point is divided into multiple basic service set identifiers and each basic service set identifier is assigned an independent BSS coloring value. The WiFi access point assigns the switching power supplies at different positions in the master-slave hierarchy to the corresponding basic service set identifiers. The WiFi access point monitors the BSS coloring value in the air interface physical layer preamble. When it identifies a co-channel interference signal with a different BSS coloring value than that of its own system, it triggers an enhanced distributed channel access mechanism reconfiguration. It assigns a preset minimum arbitration inter-frame interval and contention window parameters to the access category carrying the master-level switching power supply cooperative control message. When the WiFi station in the switching power supply detects that the channel is idle and meets the minimum arbitration inter-frame interval, it sends a cooperative control message carrying a master-slave synchronization timing tag. The slave-level switching power supply adjusts the conduction timing of its own switching transistors according to the received master-slave synchronization timing tag to achieve phase-locked operation with the master-level switching power supply.

2. The WiFi-based switching power supply collaborative control system according to claim 1, characterized in that, The process of dividing the WiFi access point into multiple basic service set identifiers and assigning an independent BSS coloring value to each basic service set identifier includes: the WiFi access point pre-stores a master-slave hierarchy mapping table for the switching power supply; when the WiFi access point receives an association request frame sent by the switching power supply, it parses the power topology identity field carried in the association request frame; the WiFi access point queries the master-slave hierarchy mapping table based on the power topology identity field to determine the master-slave hierarchy position of the switching power supply; the WiFi access point generates a specific basic service set identifier corresponding to the master-slave hierarchy position; simultaneously, it calls a random number generator to generate a BSS coloring value bound to the specific basic service set identifier; and writes the BSS coloring value into the physical layer aggregation process sub-header of the beacon frame and broadcasts it outward.

3. The WiFi-based switching power supply collaborative control system according to claim 1, characterized in that, The monitoring of the BSS coloring value in the air interface physical layer preamble of the WiFi access point includes: the physical layer chip of the WiFi access point continuously demodulates the received radio frequency signal, extracts the signaling field in the physical layer preamble, extracts a preset length of BSS coloring bits from the signaling field, converts the BSS coloring bits into decimal values, performs a matching operation on the decimal values ​​with the locally stored set of valid BSS coloring values, and when the result of the matching operation is a mismatch, records the decimal value corresponding to the mismatch and the receiving timestamp, and reports the interference characteristics containing the decimal value to the MAC layer of the WiFi access point.

4. The WiFi-based switching power supply collaborative control system according to claim 1, characterized in that, The triggering of the enhanced distributed channel access mechanism reconfiguration includes: after the MAC layer of the WiFi access point receives interference features that are not the BSS coloring value of the local system, it searches the current enhanced distributed channel access parameter table, modifies the arbitration inter-frame interval value of the access category of the corresponding cooperative control message in the enhanced distributed channel access parameter table to zero, and sets the minimum and maximum contention window values ​​of the access category to preset fixed values. The WiFi access point generates an action management frame carrying the modified parameters and sends the action management frame to all the switching power supplies in the associated state.

5. The WiFi-based switching power supply collaborative control system according to claim 1, characterized in that, The sending of the cooperative control message carrying the master-slave synchronization timing tag includes: when the WiFi station of the master-level switching power supply detects that the duration of the channel idle state has reached the minimum arbitration inter-frame interval at the local physical layer, it encapsulates the current phase value output by the local phase-locked loop circuit into the frame body field of the WiFi data frame to form the master-slave synchronization timing tag, adds a type identifier before the frame body field, and the WiFi station encapsulates the data frame with the type identifier and the master-slave synchronization timing tag into a MAC layer header and a physical layer header, and sends the encapsulated data frame to the air interface through the antenna.

6. The WiFi-based switching power supply collaborative control system according to claim 5, characterized in that, The slave-level switching power supply adjusts the conduction timing of its local switching transistors based on the received master-slave synchronization timing tag, including: after receiving the cooperative control message, the WiFi station of the slave-level switching power supply strips the MAC layer header and physical layer header of the cooperative control message, extracts the current phase value from the frame body field, the master control chip of the slave-level switching power supply uses the current phase value as a reference phase input to the phase comparator of the local digital phase-locked loop, the phase comparator calculates the phase difference between the reference phase and the local sampled phase, converts the phase difference into a phase shift compensation amount of the pulse width modulation signal, and superimposes the phase shift compensation amount onto the original carrier phase of the pulse width modulation signal.

7. The WiFi-based switching power supply collaborative control system according to claim 2, characterized in that, The power topology identity field is generated through the following steps: After the switching power supply is powered on, it identifies its own master-slave physical topology position through the hardware pin level status. The main control chip of the switching power supply reads the hardware pin level status and queries the locally stored level-identity mapping table to generate the power topology identity field containing the hierarchical code and serial number. The switching power supply fills the power topology identity field into the vendor-specific information element of the probe request frame. After completing the association of the specific basic service set identifier, the switching power supply writes the power topology identity field and the allocated BSS coloring value into non-volatile memory to form a binding relationship table.

8. The WiFi-based switching power supply collaborative control system according to claim 3, characterized in that, The step of reporting the interference features containing the decimal value to the MAC layer of the WiFi access point includes: the physical layer of the WiFi access point cumulatively records the number of times a received decimal value that does not match the set of valid BSS coloring values ​​within a preset statistical time window; when the number exceeds a preset interference threshold, the physical layer generates an interference statistical vector containing the decimal value, the number, and the statistical time window, and sends the interference statistical vector to the enhanced distributed channel access control module of the MAC layer through the service access point primitive between the physical layer and the MAC layer.

9. The WiFi-based switching power supply collaborative control system according to claim 4, characterized in that, After the action management frame is sent to all the power supplies in the associated state, the following steps are performed: the MAC layer of the WiFi access point starts an interference cancellation timer. During the timing of the interference cancellation timer, the WiFi access point continuously monitors the BSS coloring value in the air interface physical layer preamble. When no co-channel interference signal with a BSS coloring value other than that of this system is detected within multiple consecutive beacon intervals, the MAC layer of the WiFi access point generates an action management frame to restore the default parameters. The action management frame to restore the default parameters is sent to the power supply to restore the arbitration inter-frame interval value and contention window value of the access category.

10. The WiFi-based switching power supply collaborative control system according to claim 5, characterized in that, Before encapsulating the current phase value output by the local phase-locked loop circuit into the frame body field of the WiFi data frame to form the master-slave synchronization timing tag, the following steps are performed: the master switching power supply reads the count value of the local real-time clock counter, performs a difference calculation between the count value and the receiving timestamp when the beacon frame sent by the WiFi access point is received, obtains the clock drift offset, the master switching power supply performs a concatenation operation between the clock drift offset and the current phase value, encapsulates the concatenated data packet as the new master-slave synchronization timing tag into the frame body field, and adds a cyclic redundancy check code to the end of the frame body field.

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