A communication method for a power equipment system and a power equipment system

Abstract

This application discloses a communication method and a power equipment system for power equipment systems, belonging to the field of communication technology. The method is applied to a master control device that communicates with multiple slave devices, including: updating its own configuration parameters according to configuration information preset by a host computer; sending the configuration parameters to each slave device to update the configuration parameters of each slave device and establishing a communication link with each slave device; sending a sampling trigger command to the slave devices according to the communication link, so that the slave devices can sample and obtain sampling data according to the sampling trigger command; generating a pulse width modulation data command according to the sampling data uploaded by the slave devices, and sending the pulse width modulation data command to the slave devices to drive the slave devices to execute the pulse width modulation data command. This application realizes reliable communication between the master control device and multiple slave devices by constructing a communication method for the master control device and slave devices, thereby improving the collaborative control accuracy of the power equipment system.

Description

Technical Field

[0001] This application relates to the field of communication technology, specifically to a communication method and a power equipment system for power equipment systems. Background Technology

[0002] In power equipment systems such as multi-drive frequency converter systems, communication between the master control equipment and slave equipment is a crucial link in realizing the issuance of control commands, the feedback of sampled data, and the coordinated operation of the entire machine. Currently, power equipment systems often use wired communication methods based on electrical signals, such as differential pairs and serial level signals, to achieve basic data exchange.

[0003] Wired communication based on electrical signals suffers from poor anti-interference capabilities and insufficient transmission stability due to the complex electromagnetic environment of multi-node topologies. This leads to unreliable communication between the master control device and multiple slave devices, hindering precise coordinated control and thus limiting the coordinated control accuracy and operational reliability of power equipment systems. Therefore, achieving reliable communication between the master control device and multiple slave devices to improve the coordinated control accuracy of power equipment systems is a pressing issue that needs to be addressed. Summary of the Invention

[0004] This application provides a communication method and a power equipment system for power equipment systems, aiming to solve the problem of reliable communication between master control equipment and multiple slave equipment, and improve the collaborative control accuracy of power equipment systems.

[0005] In a first aspect, a communication method for a power equipment system is provided, applied to a master control device, which communicates with multiple slave devices. The method includes: updating its own configuration parameters according to configuration information preset by a host computer; sending the configuration parameters to each slave device to update the configuration parameters of each slave device, thereby establishing a communication link with each slave device; sending a sampling trigger command to the slave devices according to the communication link, so that the slave devices can sample and obtain sampling data according to the sampling trigger command; generating a pulse width modulation data command based on the sampling data uploaded by the slave devices, and sending the pulse width modulation data command to the slave devices to drive the slave devices to execute the pulse width modulation data command.

[0006] As one possible implementation, the configuration parameters include the carrier period and the sampling advance time. The slave device sends a sampling trigger command based on the communication link, causing the slave device to sample and obtain sampled data according to the sampling trigger command. This includes: cyclically counting based on the carrier period count value, and generating a sampling trigger signal when the count value is the sampling advance time count value or the difference between the carrier period count value and the sampling advance time count value; generating a sampling trigger command based on the sampling trigger signal, and sending the sampling trigger command to the slave device, so as to prompt the slave device to collect and upload sampled data before the master device enters an interrupt.

[0007] As one possible implementation, a pulse width modulation (PWM) data instruction is generated based on the sampling data uploaded by the slave device, and the PWM data instruction is sent to the slave device to drive the slave device to execute the PWM data instruction. This includes: calculating PWM data based on the sampling data uploaded by the slave device; and in response to a count value exceeding a preset range triggering an interrupt state, generating a PWM data instruction based on the PWM data and sending it to the slave device to drive the slave device to execute the PWM data instruction.

[0008] As one possible implementation, the method further includes: sending instructions in the form of communication frames, the communication frames including instruction words for indicating instruction type and instruction priority.

[0009] As one possible implementation, the method further includes: sending a heartbeat frame with a disconnection detection command to the slave device according to a preset heartbeat cycle, and receiving a heartbeat response from the slave device in response to the heartbeat frame; monitoring the reception time of the heartbeat response, and when the reception time of the heartbeat response exceeds the preset reception time, triggering the fault handling process of the master control device to broadcast a global shutdown command to the slave device and send fault information to the host computer.

[0010] As one possible implementation, the method further includes: sending a communication frame to the slave device so that the slave device can verify the communication frame and send a request to retransmit if the verification fails; when the number of consecutive requests to retransmit from the slave device exceeds the preset maximum number of retransmissions, performing a disconnection detection judgment, and when the result of the disconnection detection judgment is a disconnection, triggering the fault handling process of the master control device and sending fault information to the slave device.

[0011] Secondly, this application also provides a communication method for a power equipment system, applied to a slave device, wherein the slave device is communicatively connected to a master control device that performs the above-described communication method. The method includes: receiving configuration parameters sent by the master control device to update its own configuration parameters and establishing a communication link with the master control device; receiving a sampling trigger instruction sent by the master control device according to the communication link, performing sampling according to the sampling trigger instruction to obtain sampling data, so that the master control device generates a pulse width modulation data instruction based on the sampling data; receiving the pulse width modulation data instruction sent by the master control device, performing soft interlocking according to the pulse width modulation data instruction to obtain multiple drive signals, and driving multiple power devices to perform actions according to the multiple drive signals respectively.

[0012] As one possible implementation, the method further includes: monitoring the reception interval between two adjacent heartbeat frames from the master control device; determining a disconnection fault when the reception interval exceeds a preset multiple of the heartbeat cycle; executing a fault handling procedure based on the disconnection fault and sending fault information to the master control device; wherein the fault handling procedure includes: setting the drive signal to a preset safe state and writing a fault flag in the local status register to complete the local fault solidification.

[0013] As one possible implementation, the method further includes: receiving a communication frame sent by the master control device, verifying the communication frame, executing the instruction contained in the communication frame when the verification passes, and sending a request to retransmit an instruction to the master control device when the verification fails, so that the master control device retransmits the communication frame according to the retransmission instruction; when the retransmitted communication frame fails the verification or is not received, executing a fault handling procedure and sending fault information to the master control device.

[0014] Thirdly, this application also provides a power equipment system, including: a master control device and a plurality of slave devices communicatively connected to the master control device; wherein the master control device performs the communication method described above; or, the slave devices perform the communication method described above.

[0015] Compared with the prior art, the communication method and power equipment system provided in this application solve the problems of unreliable traditional wired electrical signal communication and low collaborative control accuracy by constructing a communication method for master control equipment and slave equipment, thereby realizing reliable communication between master control equipment and multiple slave equipment and improving the collaborative control accuracy of power equipment system. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram illustrating the application scenario provided in the embodiments of this application; Figure 2 This is a data interaction diagram between the master control device and the slave device provided in the embodiments of this application; Figure 3 This is a flowchart of a communication method for a power equipment system provided in an embodiment of this application. Figure 1 ; Figure 4 This is a flowchart of a communication method for a power equipment system provided in an embodiment of this application. Figure 2 ; Figure 5This is a schematic diagram of sampling triggering provided in an embodiment of this application; Figure 6 This is a schematic diagram of the retransmission mechanism provided in the embodiments of this application. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] In the description of this application, the use of "applies to" or "is configured to" implies open and inclusive language, which does not exclude the applicability to or configuration to devices performing additional tasks or steps. Additionally, the use of "based on" implies openness and inclusiveness, because processes, steps, calculations, or other actions "based on" one or more conditions or values ​​may in practice be based on additional conditions or values ​​beyond those conditions.

[0020] In this application, the term "exemplary" is used to mean "used as an example, illustration, or description." Any embodiment described as "exemplary" in this application is not necessarily to be construed as being more preferred or advantageous than other embodiments. The following description is provided to enable any person skilled in the art to make and use this application. Details are set forth in the following description for purposes of explanation. It should be understood that those skilled in the art will recognize that this application can be made without using these specific details. In other instances, well-known structures and processes are not described in detail to avoid obscuring the description of this application with unnecessary detail. Therefore, this application is not intended to be limited to the embodiments shown, but is consistent with the broadest scope of the principles and features disclosed in this application.

[0021] First, the application scenarios of this application will be described to enable those skilled in the art to understand the content of this application. For example... Figure 1 As shown in the embodiments of this application, the communication method for power equipment systems can be applied to multi-drive frequency converter systems, wherein the multi-drive frequency converter system includes a rectifier side and an inverter side.

[0022] The rectifier side includes a rectifier controller, rectifier units, and an LCL filter. External AC power from the grid is connected to the rectifier side, where two rectifier units perform AC / DC conversion, transforming AC into DC. The LCL filter is connected in series between the two rectifier units to filter out harmonics generated during rectification, optimizing power quality on the grid side. The rectifier controller, acting as the control unit on the rectifier side, establishes fiber optic communication links with both rectifier units via its own optical fiber links. It further expands these links using an added fiber optic extension module to establish fiber optic communication with the LCL filter, enabling coordinated control of multiple devices on the rectifier side. The DC power output from the rectifier units is collected on the DC bus, providing a unified DC power supply to all units on the inverter side, achieving centralized power distribution for the multi-drive inverter system.

[0023] The inverter side includes an inverter master controller and inverter units. Three inverter units are connected to the DC bus, responsible for converting DC power into AC power with adjustable frequency and voltage to drive their respective motor loads. The inverter master controller, as the control unit on the inverter side, establishes fiber optic communication links with the first and second inverter units, and further expands these links with the third inverter unit via an added fiber optic extension module, enabling precise speed regulation and operation control of each motor.

[0024] Figure 1 In this diagram, T and R represent independent transmit and receive links. The rectifier master controller and inverter master controller act as master control devices, the rectifier unit and inverter unit act as execution modules of slave devices, and the LCL filter acts as a sampling module of slave devices. They execute the communication method for power equipment systems provided in this application embodiment to realize data transmission between the rectifier and inverter sides, and to control voltage and motors. Specifically, the rectifier unit and inverter unit, as execution modules of slave devices, are responsible for uploading sampled data and executing the issued pulse width modulation data commands, while the LCL filter, as a sampling module of slave devices, is responsible for uploading sampled data.

[0025] It is understood that the above application scenarios are merely exemplary descriptions to facilitate understanding of the technical solutions of this application by those skilled in the art, and do not constitute a limitation on the scope of protection or application of this application.

[0026] In a first aspect, embodiments of this application provide a communication method for a power equipment system, applied to a master control device, wherein the master control device is communicatively connected to multiple slave devices.

[0027] The power equipment system includes a master control unit and multiple slave devices, each of which includes an execution module and a sampling module. The master control unit and each slave device can adopt a master-slave half-duplex or full-duplex fiber optic communication architecture. Specifically, the master control unit can establish point-to-point fiber optic communication links with the execution modules and sampling modules of each slave device. Each link can be configured with independent transmit and receive channels to achieve bidirectional, interference-free transmission. Furthermore, backup fiber optic communication links can be added for critical nodes and critical communication paths to enable failover of faulty links and improve communication reliability.

[0028] Among them, the master control device, as the leading node for timing and triggering, is responsible for sending pulse width modulation data, sampling triggering and other instructions to subordinate slave devices, and sending heartbeat frames to monitor the link status and manage the retransmission mechanism to ensure the coordinated operation of multiple devices.

[0029] Slave devices are responsible for sampling, power device driving, and local fault detection according to the instructions of the master device, and for transmitting the sampled data or fault information back to the master device. Slave devices include sampling modules and execution modules.

[0030] The sampling module is a sensing and detection node in the power equipment system, used to collect various operational data. It is typically deployed near signal detection points such as grid-side incoming lines, LCL filters, or DC buses, responsible for collecting sampling data such as voltage, current, and temperature and uploading it to the main control equipment. The execution module is a power execution node in the power equipment system, used to respond to pulse width modulation data commands from the main control equipment to drive power devices. It is usually integrated inside power modules such as rectifier units and inverter units, responsible for parsing the drive signals of power devices from the pulse width modulation data commands issued by the main control equipment, and simultaneously collecting operating status data as sampling data to upload to the main control equipment. In addition, it also handles local fault detection and fault information uploading, such as overcurrent and overtemperature.

[0031] Understandably, the master control device can be configured with a fixed number of fiber optic communication links to connect a fixed number of slave devices for fiber optic communication. When the number of slave devices increases, the master control device can be equipped with fiber optic expansion modules to expand the fiber optic communication links and connect more slave devices for fiber optic communication.

[0032] like Figure 2 and Figure 3 As shown, the communication method for power equipment systems includes steps S100 to S400, which will be described in detail below.

[0033] Step S100: Update its own configuration parameters according to the configuration information preset by the host computer.

[0034] The master control device can receive configuration information sent by the host computer via wired or wireless means, and update its configuration parameters, including communication parameters and control parameters, based on the configuration information. For example, control parameters may include modulation frequency, dead time, and dead time compensation parameters, while communication parameters may include carrier period, sampling advance time, and delay compensation time.

[0035] In the above implementation, step S100 updates the configuration parameters of the main control device through the configuration information preset by the host computer in order to adapt to the command interaction and execution of the power equipment system.

[0036] Step S200: Send the configuration parameters to each slave device to update the configuration parameters of each slave device and establish a communication link with each slave device.

[0037] The master control device generates configuration parameter commands based on the configuration parameters and sends these commands to the execution and sampling modules of each slave device via its own or extended fiber optic communication links. After initialization, the execution and sampling modules of each slave device update their configuration parameters according to the commands sent by the master control device, ensuring consistency between the configuration parameters of the master control device and each slave device to establish a handshake connection.

[0038] After the configuration parameters of the master control device and the slave devices are updated and agreed upon, the master control device and each slave device establish a communication link through handshake interaction, providing a communication foundation for subsequent command issuance and data upload.

[0039] In the communication link between the master and slave devices, instructions are sent in the form of communication frames. The design of communication frames must balance physical layer transmission compatibility with the efficiency and accuracy of logical layer instruction transmission.

[0040] For example, the communication frame uses a standardized byte transmission encoding rule at the physical layer. Each byte is transmitted as a 10-bit encoded structure, specifically 1 start bit, 8 data bits, and 1 stop bit. The transmission order follows the LSB (Least Significant Bit) principle. This standardized byte transmission encoding rule is compatible with common UART (Universal Asynchronous Receiver and Transmitter) and USART (Universal Synchronous Asynchronous Receiver and Transmitter) interfaces, which can reduce the hardware adaptation costs of master and slave devices and ensure physical layer compatibility of data transmission.

[0041] In addition, a command word is required in the communication frame to indicate the type of command encapsulated within the frame. As one implementation of the communication frame, it includes a command word representing the command type and command priority. Different command words can represent different command types, and the command priority can be determined based on the size of the command word. For example, the command word corresponding to a pulse width modulation (PWM) data command is 0001, and the command word corresponding to a retransmission request command is 0010. Since 0001 is less than 0010, the command priority of the PWM data command is lower than that of the retransmission request command.

[0042] By using the above implementation method, the instruction type and instruction priority can be represented simultaneously by the instruction word. Instruction type identification and instruction priority determination can be completed based on the same field, which shortens the instruction parsing and response time.

[0043] For example, two types of communication frames are described: one from the master device and the other from the slave device.

[0044] Communication frames from the master control device: Within the frame, the instruction word corresponds to the defined instruction type, including pulse width modulation data instructions, request retransmission instructions, disconnection detection instructions, reset instructions, configuration parameter instructions, sampling trigger instructions, and power device forced switching instructions. The communication frames adopt a variable length design. Communication frames for the five instruction types, such as pulse width modulation data instructions and request retransmission instructions, are 2 bytes long; communication frames for power device forced switching instructions are 3 bytes long; and communication frames for parameter configuration instructions are 18 bytes long. To ensure data transmission accuracy, communication frames from the master control device employ a CRC-8 check mechanism to verify the integrity and accuracy of the data within the frame, thus avoiding data distortion during link transmission. The engineering polynomial of the CRC-8 check mechanism is 0x07, with an initial value of 0x00. Examples of communication frames from the master control device are shown in Table 1.

[0045] Table 1

[0046] In Table 1, CMD represents the instruction type. Taking the pulse width modulation data instruction CMD_PWM as an example, the first 4 bits of the 0th byte store the A-phase PWM, B-phase PWM, C-phase PWM and PWM enable signal, and the last 4 bits store the instruction word 0001, which represents the instruction type and instruction priority; the 1st byte stores the 8-bit checksum of CRC-8.

[0047] Communication frames from slave devices: Within each frame, the instruction word corresponds to a defined instruction type. Instruction types include execution module sampling data transmission instructions, sampling module sampling data transmission instructions, retransmission request instructions, disconnection detection instructions, fault instructions, and version number instructions. Communication frames also employ a variable length design. The communication frame for execution module / sampling module sampling data transmission instructions is 15 bytes, the retransmission request instruction is 3 bytes, the disconnection detection instruction is 4 bytes, and the fault and version number instructions are 5 bytes. Communication frames from slave devices use the Modbus CRC-16 check mechanism, which satisfies the reliability requirements of data verification, is compatible with historical Modbus check specifications, and can adapt to redundant check application scenarios. The engineering polynomial of the Modbus CRC-16 check mechanism is 0xA001, with an initial value of 0xFFFF. Examples of communication frames from slave devices are shown in Table 2.

[0048] Table 2

[0049] In Table 2, CMD represents the instruction type. Taking the instruction to send sampled data (CMD_USAMP) as an example, the first 4 bits of the 0th byte are 0, and the last 4 bits represent the instruction type and instruction priority instruction word 0001; bytes 1-12 store the packaged current, voltage, and temperature sampled data, totaling 12 bytes; bytes 13-14 store the 16-bit checksum of CRC-16.

[0050] In the above implementation, step S200 updates the configuration parameters of the slave device through the master control device, initiates a handshake interaction and establishes a communication link between the master control device and the slave device with consistent configuration parameters, and transmits instructions in the form of communication frames through the communication link. The instruction type and instruction priority are simultaneously represented by instruction words in the communication frame, so as to realize efficient and standardized communication between the master control device and the slave device.

[0051] Step S300: Send a sampling trigger command to the slave device according to the communication link, so that the slave device can perform sampling according to the sampling trigger command to obtain sampling data.

[0052] The main control device may include a processor and a programmable logic device. The processor may be an ARM (Advanced RISC Machine) architecture processor, and the programmable logic device may be an FPGA (Field-Programmable Gate Array). The processor and the programmable logic device work together to generate and issue sampling trigger instructions, so that the execution module and sampling module of the slave device can perform sampling according to the sampling trigger instructions, providing data support for the subsequent generation of pulse width modulation data instructions.

[0053] As one implementation of step S300, the configuration parameters include carrier period and sampling advance time. Step S300 includes steps S310 to S320, which will be described in detail below.

[0054] Step S310: Perform cyclic counting based on the carrier period count value, and generate a sampling trigger signal when the count value is the sampling advance time count value or the difference between the carrier period count value and the sampling advance time count value.

[0055] The processor of the main control device sends configuration parameters to the programmable logic device (PLD). These parameters include the carrier period and the sampling advance time. Specifically, the carrier period refers to the time it takes for the pulse width modulation (PWM) signal to complete one full high-low level cycle. The sampling advance time refers to the time required to trigger the execution module and sampling module to collect data such as voltage, current, and motor angle. The sampling advance time can be flexibly set by the processor; if not set, a preset default value, such as 1000 clock cycles, is used. The clock cycle is the local clock cycle of the PLD in the main control device.

[0056] Programmable logic devices generate sampling trigger signals in advance based on configuration parameters. Specifically, such as... Figure 5 As shown, the programmable logic device (PLD) first converts the carrier period and sampling advance time into a count value based on the local clock. The PPWM counter inside the PPD cyclically counts the carrier period count value. For example, an overflow event is generated when the count value increases from 0 to the carrier period count value, and an underflow event is generated when the count value decreases from the carrier period count value to 0, thus triggering overflow and underflow events. Both overflow and underflow events trigger the processor to enter an interrupt state. For incrementing the count, a sampling trigger signal is sent to the processor when the PPWM counter count value equals the difference between the carrier period count value and the sampling advance time count value. For decrementing the count, a sampling trigger signal is sent to the processor when the PPWM counter count value equals the sampling advance time count value.

[0057] Step S320: Generate a sampling trigger command based on the sampling trigger signal and send the sampling trigger command to the slave device to prompt the slave device to collect and upload sampling data before the master device enters an interrupt.

[0058] The processor generates a sampling trigger instruction CMD_TRG based on the sampling trigger signal and sends it to the programmable logic device (PLD). The PLD, through an established point-to-point fiber optic communication link, sends the CMD_TRG instruction to each execution module and sampling module. This pre-triggers the execution and sampling modules to collect and upload sampling data such as current, voltage, and motor angle, enabling the main control device to receive and parse the sampling data before the processor enters an interrupt, thus obtaining the pulse width modulation data for execution.

[0059] As a further implementation of step S300, when the configuration parameters also include a delay compensation time, the sampling trigger command carries the delay compensation time to prompt the slave device to respond to the delay compensation time and collect and upload the sampling data in advance.

[0060] The processor also carries a delay compensation time t_comp in the sampling trigger instruction CMD_TRG to prompt the execution module and sampling module of the slave device to respond to the delay compensation time t_comp carried in the sampling trigger instruction CMD_TRG, trigger the ADC sampling circuit in advance, so as to further compensate for the transmission delay of the optical fiber communication link, ensure that the sampling time point of the slave device is accurately aligned with the carrier period start time point, and improve the sampling trigger accuracy.

[0061] As a further implementation of step S300, to reduce timing jitter, a high-precision phase-locked loop and clock distribution circuit are used at the hardware level of the main control device to provide a stable and consistent local clock for the processor and programmable logic devices. At the logic level of the programmable logic devices, a synchronous cross-clock domain FIFO or a dual-clock domain pulse synchronization circuit is used to realize the synchronization and transmission of sampling trigger signals between different clock domains.

[0062] In the above implementation, steps S310 to S320, by setting a sampling advance time, issue the sampling trigger command CMD_TRG in advance to prompt the slave device to collect and upload sampling data in advance. Furthermore, by setting a delay compensation time t_comp, the transmission delay of the command is further compensated, ensuring that the sampling time point of the slave device is precisely aligned with the carrier cycle start time point. This method ensures that the sampling data is aligned with the carrier cycle, avoiding data mis-sampling while allowing sufficient time for the master control device to process the sampling data, thereby improving the processing efficiency of the master control device.

[0063] Step S400: Generate a pulse width modulation data instruction based on the sampling data uploaded by the slave device, and send the pulse width modulation data instruction to the slave device to drive the slave device to execute the pulse width modulation data instruction.

[0064] The master control device receives the sampling data uploaded in real time by the execution module and sampling module of the slave device. Through the control algorithm, combined with the pre-configured carrier period, modulation frequency, dead time and dead time compensation parameters, it obtains the pulse width modulation data that represents the three-phase PWM waveform and generates the pulse width modulation data instruction. The pulse width modulation data instruction is then sent to the execution module of the slave device to achieve precise control of the execution module.

[0065] As one embodiment of step S400, step S400 includes steps S410 and S420, which will be described in detail below.

[0066] Step S410: Calculate pulse width modulation data based on the sampling data uploaded by the slave device.

[0067] Specifically, the processor of the master control device receives sampled data of the current carrier cycle collected by the execution module and sampling module of the slave device through a programmable logic device. It parses the sampled data and extracts real-time current, voltage, and motor angle, comparing these with the target current, voltage, and motor angle to determine the duty cycle of the PWM waveform for the next carrier cycle. The processor synchronizes the duty cycle of the PWM waveform for the next carrier cycle to the PWM waveform generator. Based on pre-configured carrier cycle, modulation frequency, dead time, and dead time compensation parameters, the PWM waveform generator generates the three-phase PWM waveform for the next carrier cycle, obtaining the pulse width modulation data for the next carrier cycle.

[0068] Step S420: In response to the count value exceeding the preset range triggering the interrupt state, generate a pulse width modulation data instruction based on the pulse width modulation data and send it to the slave device to drive the slave device to execute the pulse width modulation data instruction.

[0069] Specifically, such as Figure 5 As shown, the pulse width modulation counter inside the programmable logic device (PLD) increments from 0 to the carrier cycle count, cyclically counting. A preset range is set to (0, the carrier cycle count value). When the count value is the carrier cycle count value or 0, an overflow and underflow event are generated. The PLD sends a level signal to the processor, causing the processor to enter an interrupt state. The processor in the interrupt state then sends the pre-calculated pulse width modulation data for the next carrier cycle to the PLD.

[0070] After receiving pulse width modulation data from the processor, the programmable logic device encapsulates it into a pulse width modulation data instruction in the form of a communication frame, and sends it to the execution module of the slave device through an optical fiber communication link to drive the execution module to execute the pulse width modulation data instruction.

[0071] In the above embodiment, steps S410 to S420 complete the parsing of sampled data and the calculation of pulse width modulation data before the processor enters the interrupt state. After the processor enters the interrupt state, it quickly generates modulation pulse data instructions based on the pre-calculated pulse width modulation data to drive the execution module of the slave device. This effectively shortens the time occupied by the processor in the interrupt state, enabling rapid driving of the execution module.

[0072] In addition to steps S100 to S400 above, a disconnection detection mechanism is introduced into the communication method in order to monitor the connection status with the slave device in real time.

[0073] As one possible implementation of the disconnection detection mechanism, the disconnection detection mechanism in step S500 specifically includes steps S510 to S520, which will be described in detail below.

[0074] Step S510: Send a heartbeat frame with a disconnection detection command to the slave device according to the preset heartbeat cycle, and receive the heartbeat response returned by the slave device in response to the heartbeat frame.

[0075] Specifically, the master control device sends a heartbeat frame with a disconnection detection command (CMD_OFF) to the slave device according to a preset heartbeat cycle. The heartbeat frame carries information about the number of handshakes and receives a heartbeat response from the slave device. The heartbeat cycle can be flexibly configured by the host computer; if not configured, a default cycle, such as 5000 clock cycles, can be used.

[0076] Step S520: Monitor the heartbeat response reception time. When the heartbeat response reception time exceeds the preset reception time, trigger the fault handling process of the master control device to broadcast a global shutdown command to the slave device and send fault information to the host computer.

[0077] Specifically, the master control device continuously monitors the heartbeat response reception time of each slave device. When it detects that a slave device has not responded to the heartbeat frame after a preset reception time, it determines that a fault has occurred. At this time, the master control device executes the fault handling procedure: broadcasting a global shutdown command to the subordinate slave devices and sending fault information to the host computer or a higher-level processor.

[0078] In the above implementation, steps S510 to S520 establish a disconnection detection mechanism to monitor the communication link between the master control device and the slave device, thereby enabling timely location of faulty slave devices and achieving communication link monitoring and fault location.

[0079] In addition to step S500 above, if errors occur in the transmitted data when the master device sends instructions to the slave device, it may cause the slave device to malfunction. Similarly, if errors occur in the transmitted data when the slave device returns a response to the master device, it may cause the master device to fail to control. Therefore, step S600, a retransmission mechanism, is introduced into the communication method.

[0080] As one implementation of the retransmission mechanism, the retransmission mechanism in step S600 specifically includes steps S610 to S620, which will be described in detail below.

[0081] Step S610 includes: sending a communication frame to the slave device so that the slave device can verify the communication frame and send a request to resend if the verification fails.

[0082] Specifically, such as Figure 6 As shown, the master device sends communication frames to the slave device. The slave device performs CRC (Cyclic redundancy check) verification on each received communication frame. When the verification passes, it parses and executes the instructions in the communication frame. When the verification fails, it sends a request to the master device to resend the instructions.

[0083] Step S620: When the number of times the master control device continuously receives retransmission requests from the slave device exceeds the preset maximum number of retransmissions, a disconnection detection judgment is performed. If the result of the disconnection detection judgment is a disconnection, the fault handling process of the master control device is triggered and a fault information is sent to the slave device. The disconnection detection judgment refers to verifying the communication frames reported by the slave device and recording the number of verification failures. When the number of verification failures exceeds the preset number, it is determined to be a disconnection.

[0084] Specifically, when the master device receives a retransmission request command from the slave device, it performs a CRC check on the retransmission request command and records the number of times the check fails, to be used for disconnection detection. If the check passes, it compares whether the number of retransmission requests corresponding to the current communication frame reaches the preset maximum number of retransmissions, such as 5 times. If it is less than or equal to the preset maximum number of retransmissions, it sets the retransmission interval according to the exponential delay or fixed delay rule and retransmits the communication frame to the slave device. If it exceeds the preset maximum number of retransmissions, it performs a disconnection detection.

[0085] The disconnection detection is determined by counting the number of failed verifications. When the number of failed verifications exceeds a preset number, a disconnection is determined. At this time, the master control device sends fault information to the slave devices and triggers the fault handling process to broadcast a global shutdown command to the slave devices and send fault information to the host computer.

[0086] The maximum number of retransmissions can be set as needed. For critical instructions such as sampling trigger instructions and power device forced switching instructions, the maximum number of retransmissions can be reduced.

[0087] In the above implementation, steps S610 to S620 establish a retransmission mechanism to retransmit fault frames, thereby enhancing the communication stability between the master control device and the slave device.

[0088] Secondly, embodiments of this application also provide a communication method for a power equipment system, applied to a slave device, wherein the slave device communicates with an execution device such as... Figure 3 The communication method shown illustrates the communication connection between the master control device and the communication device.

[0089] like Figure 2 and Figure 4 As shown, a communication method for a power equipment system includes steps B100 to B300.

[0090] B100: Receives configuration parameters sent by the master control device to update its own configuration parameters and establishes a communication link with the master control device.

[0091] After the slave device is powered on and initialized, it receives configuration parameter instructions from the master device through a fiber optic communication link, parses the configuration parameter instructions, and updates the configuration parameters of the execution module and the sampling module to ensure that they are consistent with the configuration parameters of the master device. The slave device with consistent configuration parameters establishes a communication link with the master device through a handshake interaction, providing a communication foundation for subsequent instruction reception and data upload.

[0092] B200: Receives sampling trigger instructions sent by the master control device according to the communication link, performs sampling according to the sampling trigger instructions to obtain sampling data, so that the master control device can generate pulse width modulation data instructions based on the sampling data.

[0093] In this process, the slave device responds to the sampling trigger command issued by the master control device, the drive execution module collects and uploads the sampled data including the running status data, and the ADC sampling circuit of the drive sampling module collects and uploads the sampled data including the current, voltage, and motor angle, so that the master control device can generate pulse width modulation data commands based on the sampled data.

[0094] B300: Receives pulse width modulation data commands sent by the main control device, executes soft interlocking according to the pulse width modulation data commands to obtain multiple drive signals, and drives multiple power devices to perform actions according to the multiple drive signals.

[0095] The execution module of the slave device includes multiple power devices. The execution module of the slave device receives pulse width modulation data commands issued by the master device, parses the pulse width modulation data commands to obtain pulse width modulation data, performs soft interlocking on the pulse width modulation data to obtain drive signals for multiple power devices, and drives multiple power devices to perform actions according to the multiple drive signals.

[0096] Specifically, the execution module features a three-phase bridge arm topology, with each phase independently configured with upper and lower bridge arm power devices. These upper and lower bridge arm power devices can employ IGBTs (Insulated-Gate Bipolar Transistors) to achieve power conversion and output. Through the switching of the upper and lower bridge arm power devices, the DC bus voltage is inverted into a three-phase AC voltage suitable for the load motor's requirements, thereby driving the motor.

[0097] The execution module parses the pulse width modulation data instructions to extract the three-phase PWM signals, which control the power devices of the three-phase bridge arms respectively. The upper and lower bridge arm power devices of each phase cannot be turned on simultaneously; therefore, soft interlocking is performed on each phase PWM signal to generate drive signals for the upper and lower bridge arm power devices, driving them to mutually exclude each other from turning on and off. Simultaneously, the execution module performs upper and lower bridge simultaneous conduction detection, dead-time control, and narrow-pulse protection. Once a risk is detected, the fault handling procedure is immediately executed and fault information is reported, achieving safe operation of the three-phase bridge arms.

[0098] In addition to steps B100 to B300 above, step B400, a disconnection detection mechanism, is introduced into the communication method.

[0099] As one possible implementation of the disconnection detection mechanism, the disconnection detection mechanism in step B400 will be described in detail below.

[0100] Step B400: Monitor the reception interval between two adjacent heartbeat frames from the master control device. When the reception interval exceeds a preset multiple of the heartbeat cycle, it is determined to be a disconnection fault. Execute the fault handling procedure according to the disconnection fault and send fault information to the master control device. The fault handling procedure includes: setting the drive signal to a preset safe state and writing a fault flag in the local status register to complete the local fault fixation.

[0101] Specifically, the slave device, based on its built-in handshake counter, continuously monitors the reception interval between two adjacent heartbeat frames after a successful handshake. The slave device pre-configures a disconnection fault redundancy coefficient function code B509 to represent the fault tolerance capability for disconnection detection; its maximum value can be 10, and its minimum value can be 0. If the disconnection fault redundancy coefficient function code B509 is not configured with a specific value, it defaults to 0.

[0102] If B509 is 0, it indicates no redundancy configuration: when the slave device detects a heartbeat frame reception interval exceeding 1.5 times the heartbeat cycle, it immediately determines it as a disconnection fault. If B509 is not 0, it indicates redundancy configuration: a disconnection fault is only determined when the slave device detects a heartbeat frame reception interval exceeding B509 × 1.5 times the heartbeat cycle. The slave device responds to the disconnection fault by executing the fault handling procedure and sending fault information to the master device.

[0103] In the above implementation, step B400 sets up a disconnection detection mechanism to monitor the communication links of slave devices and master devices, and to detect faulty communication links in a timely manner.

[0104] In addition to step B400 above, step B500, a retransmission mechanism, is introduced into the communication method.

[0105] As one implementation of the retransmission mechanism, the retransmission mechanism in step B500 specifically includes steps B510 to B520, which will be described in detail below.

[0106] Step B510: Receive the communication frame sent by the master control device, verify the communication frame, execute the instruction contained in the communication frame when the verification passes, and send a request to retransmit the instruction to the master control device when the verification fails, so that the master control device can retransmit the communication frame according to the retransmission instruction. Specifically, such as Figure 6 As shown, the slave device is configured to: upon receiving communication frames such as pulse width modulation data instructions and configuration parameter instructions from the master device, first perform CRC check on the communication frame; if the check passes, the slave device executes the instructions carried in the communication frame; if the check fails, it sends a request to retransmit an instruction to the master device.

[0107] Step B520: When the retransmitted communication frame fails the verification or is not received, execute the fault handling procedure and send fault information to the main control device.

[0108] Specifically, the slave device performs CRC verification on the communication frames retransmitted by the master device. When the verification passes, the slave device executes the instructions carried in the retransmitted communication frame. When the verification fails or the retransmitted communication frame is not received for an extended period, the slave device executes a fault handling procedure and sends fault information to the master device. The fault handling procedure includes: setting the drive signal to a preset safe state and writing a fault flag in the local status register to complete the local fault fixation.

[0109] It should be noted that the communication methods described above for slave devices and for master devices work together to enable communication and interaction between the master device and each slave device in the power equipment system.

[0110] Thirdly, embodiments of this application also provide a power equipment system, including: a main control device and a plurality of slave devices communicatively connected to the main control device; wherein, the main control device performs, for example... Figure 3 The communication method shown; or, the slave device performs, as... Figure 4 The communication method shown.

[0111] As one implementation of master control equipment and slave equipment, the master control equipment includes a rectifier master control and an inverter master control, and the slave equipment includes a rectifier unit and an inverter unit as execution modules and a filter unit as a sampling module.

[0112] It is understood that the communication method and power equipment system provided in this application solve the problems of unreliable traditional wired electrical signal communication and low collaborative control accuracy by constructing a communication method for master control equipment and slave equipment, thereby realizing reliable communication between master control equipment and multiple slave equipment and improving the collaborative control accuracy of power equipment system.

[0113] The foregoing has provided a detailed description of a communication method and a power equipment system for power equipment systems according to embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and its core ideas. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application. In addition, the descriptions of each embodiment in the above embodiments have different emphases; parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments.

Claims

1. A communication method for a power equipment system, characterized in that, Applied to a master control device, wherein the master control device is communicatively connected to multiple slave devices, the method includes: Update its own configuration parameters according to the preset configuration information of the host computer; The configuration parameters are sent to each of the slave devices to update the configuration parameters of each slave device and establish a communication link with each of the slave devices; A sampling trigger command is sent to the slave device via the communication link, so that the slave device performs sampling according to the sampling trigger command to obtain sampling data; A pulse width modulation (PWM) data instruction is generated based on the sampling data uploaded by the slave device, and the PWM data instruction is sent to the slave device to drive the slave device to execute the PWM data instruction.

2. The communication method according to claim 1, characterized in that, The configuration parameters include carrier period and sampling advance time; the step of the slave device sending a sampling trigger command according to the communication link, so that the slave device performs sampling to obtain sampling data according to the sampling trigger command, includes: The system performs a cyclic count based on the carrier period count value, and generates a sampling trigger signal when the count value is the count value of the sampling advance time or the difference between the count value of the carrier period and the count value of the sampling advance time. A sampling trigger command is generated based on the sampling trigger signal, and the sampling trigger command is sent to the slave device to prompt the slave device to collect and upload the sampling data before the master device enters an interrupt.

3. The communication method according to claim 2, characterized in that, The step of generating a pulse width modulation (PWM) data instruction based on the sampled data uploaded by the slave device, and sending the PWM data instruction to the slave device to drive the slave device to execute the PWM data instruction, includes: Calculate pulse width modulation data based on the sampled data uploaded by the slave device; In response to the count value exceeding a preset range triggering an interrupt state, a pulse width modulation data instruction is generated based on the pulse width modulation data and sent to the slave device to drive the slave device to execute the pulse width modulation data instruction.

4. The communication method according to claim 1, characterized in that, The method further includes: sending instructions in the form of communication frames, the communication frames including instruction words for indicating instruction type and instruction priority.

5. The communication method according to claim 1, characterized in that, The method further includes: According to a preset heartbeat cycle, a heartbeat frame with a disconnection detection command is sent to the slave device to receive a heartbeat response from the slave device in response to the heartbeat frame. The system monitors the reception time of the heartbeat response. When the reception time of the heartbeat response exceeds the preset reception time, it triggers the fault handling process of the master control device to broadcast a global shutdown command to the slave device and send fault information to the host computer.

6. The communication method according to claim 1, characterized in that, The method further includes: A communication frame is sent to the slave device so that the slave device can verify the communication frame and send a retransmission request if the verification fails. When the number of times the request to retransmit the command received from the slave device is greater than the preset maximum number of retransmissions, a disconnection detection judgment is performed. If the result of the disconnection detection judgment is a disconnection, the fault handling process of the master control device is triggered and a fault information is sent to the slave device.

7. A communication method for a power equipment system, applied to a slave device, wherein the slave device is communicatively connected to a master control device performing the communication method according to any one of claims 1 to 6, characterized in that, The method includes: It receives configuration parameters sent by the master control device to update its own configuration parameters and establishes a communication link with the master control device; The main control device receives a sampling trigger command sent by the main control device according to the communication link, and performs sampling according to the sampling trigger command to obtain sampling data, so that the main control device generates a pulse width modulation data command based on the sampling data; The system receives the pulse width modulation data instruction sent by the main control device, executes a soft interlock to obtain multiple drive signals according to the pulse width modulation data instruction, and drives multiple power devices to perform actions according to the multiple drive signals.

8. The communication method according to claim 7, characterized in that, The method further includes: The system monitors the interval between two consecutive heartbeat frames from the main control device. When the interval exceeds a preset multiple of the heartbeat cycle, it determines that a disconnection fault has occurred. Based on the disconnection fault, the system executes a fault handling procedure and sends fault information to the main control device. The fault handling process includes: setting the drive signal to a preset safe state and writing a fault flag into the local status register to complete the local fault fixation.

9. The communication method according to claim 7, characterized in that, The method further includes: The system receives communication frames sent by the master control device, verifies the communication frames, executes the instructions contained in the communication frames when the verification passes, and sends a request to retransmit a command to the master control device when the verification fails, so that the master control device retransmits the communication frames according to the retransmission command. When the retransmitted communication frame fails verification or is not received, a fault handling procedure is executed and a fault information is sent to the main control device.

10. A power equipment system, characterized in that, include: A master control device and multiple slave devices that are communicatively connected to the master control device; The main control device executes the communication method as described in any one of claims 1 to 6; Alternatively, the slave device performs the communication method as described in any one of claims 7 to 9.

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