Communication protocol converter for generator excitation system

Abstract

The utility model discloses a communication protocol converter used for a generator excitation system, comprising an STM32F407 chip, a CAN module, RS-485 modules, two paths of Ethernet modules and a B code time synchronization module, the CAN module is electrically connected with the STM32F407 chip, the CAN module is used for communicating with the generator excitation system, the RS-485 modules are electrically connected with the STM32F407 chip, the RS-485 modules are used for being connected with an external device supporting an RS-485 protocol, and the two paths of Ethernet modules are connected with the B code time synchronization module. The two paths of Ethernet modules are electrically connected with the STM32F407 chip, one path of Ethernet module is used for communicating with a generator excitation system, the other path of Ethernet module is connected with an external device supporting an MODBUS-TCP protocol, the B code time synchronization module is electrically connected with the STM32F407 chip, and the STM32F407 chip is electrically connected with the STM32F407 chip. And the B code time synchronization module is used for ensuring the time consistency of the communication protocol converter and the generator excitation system or the external equipment. The utility model has the advantages of being compatible with the generator excitation system and improving the communication efficiency of the generator excitation system and the external equipment.

Description

Technical Field

[0001] The utility model relates to the field of communications, and more particularly to a communication protocol converter for a generator excitation system. Background Art

[0002] The generator excitation system refers to the device and control system responsible for providing the excitation current to generate a rotating magnetic field within a generator set. It includes components such as the excitation power supply, excitation winding, and excitation controller. The excitation power supply is typically provided by a DC power supply, which transmits the excitation current to the generator rotor through the excitation winding. The excitation controller monitors and adjusts the excitation current to control the generator's output voltage and frequency. The primary function of the generator excitation system is to control the generator's output voltage and current, ensuring stable power output during operation.

[0003] The existing technology has the following defects: Currently, the external communication of the generator excitation system is mainly achieved through RS-485, but the transmission speed and communication efficiency of RS-485 cannot meet the growing demand of various power stations for the external communication performance of the excitation system. Utility Model Content

[0004] In order to overcome the above technical defects, the utility model provides a communication protocol converter for a generator excitation system, which is compatible with the generator excitation system and improves the communication efficiency between the generator excitation system and external equipment.

[0005] In order to solve the above problems, the present invention is implemented according to the following technical solutions: a communication protocol converter for a generator excitation system, comprising:

[0006] STM32F407 chip;

[0007] A CAN module, the CAN module is electrically connected to the STM32F407 chip, and the CAN module is used to communicate with the generator excitation system;

[0008] RS-485 module, each of which is electrically connected to the STM32F407 chip, and is used to connect to an external device that supports the RS-485 protocol;

[0009] Two Ethernet modules, both of which are electrically connected to the STM32F407 chip, one of which is used to communicate with the generator excitation system, and the other is connected to an external device that supports the MODBUS-TCP protocol;

[0010] A B-code timing module is electrically connected to the STM32F407 chip and is used to ensure the time consistency between the communication protocol converter and the generator excitation system or external equipment.

[0011] In one embodiment, the communication protocol converter further includes an RS-232 module, the RS-232 module is electrically connected to the STM32F407 chip, and the RS-232 module is used for downloading and debugging the communication protocol converter.

[0012] In one embodiment, the communication protocol converter further includes a FLASH memory, which is electrically connected to the STM32F407 chip and is used to store program codes and constant data.

[0013] In one embodiment, the communication protocol converter further includes an SRAM memory, which is electrically connected to the STM32F407 chip, and is used to store variables, stacks, and other temporary data during runtime.

[0014] In one embodiment, the communication protocol converter further includes a switch input module, which is electrically connected to the STM32F407 chip, and is used to realize the integration and logical judgment of the input quantities of different devices.

[0015] In one embodiment, the communication protocol converter further includes a switch output module, the switch output module is electrically connected to the STM32F407 chip, and the switch output module supports switch output of custom output logic.

[0016] In one embodiment, the CAN module includes a CAN transceiver, a common-mode inductor, a filter capacitor and a TVS tube, the common-mode inductor is electrically connected to the CAN transceiver, and the filter capacitor and the TVS tube are both electrically connected to the common-mode inductor.

[0017] In one embodiment, the Ethernet module includes an Ethernet cable interface, a network port transformer and a CH395Q chip, and the Ethernet cable interface is electrically connected to the CH395Q chip through the network port transformer.

[0018] In one embodiment, the switch input module includes a switch input interface, an indicator light and an optocoupler, and the indicator light and the optocoupler are electrically connected to the switch input interface; the switch output module includes a shift register, and the shift register has multiple data input terminals and multiple data output terminals.

[0019] In one embodiment, the number of the RS-485 modules is two, the number of the switch input modules is eight, and the number of the switch output modules is forty-eight.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] The communication protocol converter for the generator excitation system is electrically connected to the STM32F407 chip via a CAN module for communicating with the generator excitation system. Two Ethernet modules are also electrically connected to the STM32F407 chip, one of which is used for communicating with the generator excitation system, making the communication protocol converter compatible with the generator excitation system. Both RS-485 modules are electrically connected to the STM32F407 chip for connecting to external devices supporting the RS-485 protocol. The other Ethernet module is connected to an external device supporting the MODBUS-TCP protocol, thereby improving communication efficiency between the generator excitation system and external devices. A B-code timing module is also electrically connected to the STM32F407 chip to ensure timing consistency between the communication protocol converter and the generator excitation system or external devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, wherein:

[0023] Figure 1 A schematic diagram showing the internal structure of a communication protocol converter for a generator excitation system;

[0024] Figure 2 This is a schematic diagram of the internal structure of the CAN module;

[0025] Figure 3 This is the principle diagram of the RS-485 module;

[0026] Figure 4 This is the principle diagram of the Ethernet module;

[0027] Figure 5 This is a schematic diagram of the internal structure of the switch input module;

[0028] Figure 6 This is a schematic diagram of the internal structure of the switch output module.

[0029] In the figure: 1. STM32F407 chip; 2. CAN module; 3. RS-485 module; 4. Ethernet module; 5. B code timing module; 6. RS-232 module; 7. FLASH memory; 8. SRAM memory; 9. Switch input module; 10. Switch output module. DETAILED DESCRIPTION

[0030] The following describes the preferred implementation of the present invention in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention and are not used to limit the present invention. The directional words such as "upper" and "lower" involved in this article are all relative to the perspective of the drawings and are only for the convenience of description and cannot be understood as limitations on the technical solution. The "first, second..." used is only for distinguishing names and does not represent specific quantities and orders.

[0031] like Figure 1 As shown, the utility model provides a communication protocol converter for a generator excitation system, the communication protocol converter includes an STM32F407 chip 1, a CAN module 2, an RS-485 module 3, two Ethernet modules 4 and a B-code timing module 5. Among them, the CAN module 2 is electrically connected to the STM32F407 chip 1, the RS-485 modules 3 are both electrically connected to the STM32F407 chip 1, the two Ethernet modules 4 are both electrically connected to the STM32F407 chip 1, and the B-code timing module 5 is electrically connected to the STM32F407 chip 1. Specifically, the CAN module 2 and one of the Ethernet modules 4 are used for communication between different devices within the excitation system. Data from different devices in the excitation system can be transmitted to the present utility model via CAN or Ethernet for processing and storage, thereby making the communication protocol converter compatible with CAN communication and MODBUS-TCP communication between different cabinets within the generator excitation system. RS-485 module 3 is used to connect to external devices supporting the RS-485 protocol, while Ethernet module 4 connects to external devices supporting the MODBUS-TCP protocol. This not only supports connections with RS-485 devices, but also MODBUS-RTU and MODBUS-TCP communications, thereby improving communication efficiency between the generator excitation system and external devices. Furthermore, the B-code timing module 5 ensures timing consistency between the communication protocol converter and the generator excitation system or external devices.

[0032] In a specific embodiment, the internal structure principle of the CAN module 2 is as follows Figure 2As shown in the figure, CAN0_L and CAN0_H represent the signals on the CAN bus. L1 is a common-mode inductor, which attenuates common-mode interference and suppresses both internal and external interference, improving the product's anti-interference capability. C40 and C41 are filter capacitors, providing a low-impedance return path for interference, effectively reducing outgoing common-mode current and filtering external interference. D5 and D6 are TVS diodes. R13 and SW1 are used to configure the terminal resistors of the communication equipment. After passing through the protection circuit, the CAN signal is connected to the isolated CAN transceiver U2. The ADM3053 is the preferred isolated CAN transceiver. The ADM3053 creates a fully isolated interface between the STM32F407 chip 1 and the physical layer bus. It operates at a data rate of up to 1 Mbps. U2's CAN_eTX and CAN_eRX terminals are connected to the CAN interface of the STM32F407 chip 1.

[0033] In a specific embodiment, in order to further improve the communication efficiency between the generator excitation system and the external device supporting the RS-485 protocol, the number of RS-485 modules 3 is preferably two, and the internal structure principle of the RS-485 module 3 is as follows: Figure 3 As shown in the figure: A1 and B1 represent the RS-485 signal input. L6 is a common-mode inductor, which attenuates common-mode interference and suppresses both internal and external interference, improving the product's anti-interference capability. C179 and C181 are filter capacitors, providing a low-impedance return path for interference, effectively reducing outgoing common-mode current and filtering external interference. D73 and D74 are TVS diodes. R207 and SW8 configure the terminal resistors for the communication equipment. R357 and R356 are pull-up and pull-down resistors, respectively. After passing through the protection circuit, the RS-485 signal is connected to the isolated full-duplex RS-485 transceiver chip U68. The preferred isolated full-duplex RS-485 transceiver chip is the NIS83085. The STM32F407 chip 1 controls DE1 to transmit or receive data.

[0034] In a specific embodiment, the internal structure principle of the Ethernet module 4 is as follows Figure 4As shown, J2 is the Ethernet cable interface, which connects to the Ethernet chip after passing through the Ethernet port transformer T1. The preferred Ethernet chip model is the CH395Q. The Ethernet port transformer T1 serves the following functions: 1. It amplifies the signal, increasing transmission distance; 2. It isolates the chip from the outside world, improving interference resistance and protecting devices at both ends; and 3. It prevents damage to devices on both ends when connected to different power levels. The CH395Q chip includes a built-in 10 / 100M Ethernet media transport layer (MAC) and physical layer (PHY), fully compatible with the IEEE802.3 10 / 100M protocol. It also includes built-in Ethernet protocol stack firmware for IP, DHCP, ARP, ICMP, IGMP, UDP, and TCP. The STM32F407 chip 1 can conveniently communicate with the CH395Q chip via its SPI interface.

[0035] In a specific embodiment, the communication protocol converter also includes an RS-232 module 6, which is electrically connected to the STM32F407 chip 1. The RS-232 module 6 is used for downloading and debugging the communication protocol converter, thereby ensuring the normal operation of the communication protocol converter on the generator excitation system. Furthermore, the communication protocol converter includes a 128M-bit FLASH memory 7 and a 16M-bit SRAM memory 8, and the communication protocol converter also supports SD card expansion. The FLASH memory 7 is electrically connected to the STM32F407 chip 1. The FLASH memory 7 is a non-volatile memory used to store program code and constant data. It is typically used to store microcontroller startup code, application programs, and other fixed data. The SRAM memory 8 is a volatile memory used for temporary data storage. It is typically used to store runtime variables, stacks, and other temporary data. Compared to the FLASH memory 7, the SRAM memory 8 has faster read and write speeds and higher access speeds, but the stored data is lost after a power outage or restart.

[0036] In a specific embodiment, in data processing, the data after protocol conversion is stored in the FLASH memory 7 or the SRAM memory 8, and the user can customize the communication point table, that is, the correspondence between the data and the storage address. The different external devices of the utility model can be configured with their read and write data permissions through the program, and the needs of different excitation external devices are met by opening different read and write areas. For example, the open analog data area, switch data area and command area required by the power plant monitoring system, the temperature measuring element external to the generator excitation system only needs to open a part of the data writing space. More specifically, the communication protocol converter is realized by the technical means of setting the switch input module 9 and the switch output module 10. The switch input module 9 is electrically connected to the STM32F407 chip 1, and the number of switch input modules 9 is preferably eight. The internal structure principle of the switch input module 9 is as follows. Figure 5 As shown, Bin24V1 is a digital input interface. This device utilizes a low-level active-low logic. When the input to Bin24V1 is low, indicator D8 illuminates. This is then isolated by the optocoupler HCPL181, generating a 3.3V signal at Bin3V1. After passing through the inverter (preferably the CD40106B), Bin3V1 returns to a low level and is then input to the STM32F407 chip 1 for processing. The optocoupler in the digital input module 9 isolates the external digital input circuitry from the internal circuitry connected to the STM32F407 chip 1, enhancing the device's safety.

[0037] In addition, the switch output module 10 is electrically connected to the STM32F407 chip 1, and the number of the switch output modules 10 is preferably 48. The internal structure principle of the switch output module 10 is as follows: Figure 6As shown, the 74HC595 is a shift register, SIA is the shift register serial data input, and SIA_SCK is the shift register clock input. Each rising edge of the input shifts the data input into the shift register one bit. SIA_RCK is the 74HC595 internal storage register clock input, valid on rising edges. Each rising edge of the input shifts the data from one bit register to another. DOA17-DOA24 are the outputs of the 74HC595. Serial data is converted into parallel data via the switch output module 10, and each subsequent parallel data output is used as a switch output. In summary, the present invention offers a significant level of customization, allowing for customized communication point tables, switch input logic, and switch output logic for different users and devices connected to the generator excitation system. As for the communication method of the traditional generator excitation system, according to the different needs of users, it is necessary to modify the hardware and programs of multiple internal or external devices on the generator excitation system. However, after all data collection and processing are completed, the utility model only needs to modify the point table and judgment logic to meet customer needs, improve the compatibility of the generator excitation system, and better meet the needs of users.

[0038] For other structures of the communication protocol converter for a generator excitation system described in the present invention, refer to the prior art.

[0039] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A communication protocol converter for a generator excitation system, characterized in that: include: STM32F407 chip; A CAN module, the CAN module is electrically connected to the STM32F407 chip, and the CAN module is used to communicate with the generator excitation system; RS-485 module, each of which is electrically connected to the STM32F407 chip, and is used to connect to an external device that supports the RS-485 protocol; Two Ethernet modules, both of which are electrically connected to the STM32F407 chip, one of which is used to communicate with the generator excitation system, and the other is connected to an external device that supports the MODBUS-TCP protocol; A B-code timing module is electrically connected to the STM32F407 chip and is used to ensure the time consistency between the communication protocol converter and the generator excitation system or external equipment.

2. The communication protocol converter for a generator excitation system according to claim 1, characterized in that: It also includes an RS-232 module, which is electrically connected to the STM32F407 chip and is used for downloading and debugging the communication protocol converter.

3. The communication protocol converter for a generator excitation system according to claim 2, characterized in that: It also includes a FLASH memory, which is electrically connected to the STM32F407 chip and is used to store program codes and constant data.

4. The communication protocol converter for a generator excitation system according to claim 3, characterized in that: It also includes an SRAM memory, which is electrically connected to the STM32F407 chip and is used to store variables, stacks and other temporary data during runtime.

5. The communication protocol converter for a generator excitation system according to claim 4, characterized in that: It also includes a switch input module, which is electrically connected to the STM32F407 chip and is used to realize the synthesis and logical judgment of the input quantities of different devices.

6. The communication protocol converter for a generator excitation system according to claim 5, characterized in that: It also includes a switching output module, which is electrically connected to the STM32F407 chip and supports switching output of custom output logic.

7. The communication protocol converter for a generator excitation system according to claim 1, characterized in that: The CAN module includes a CAN transceiver, a common-mode inductor, a filter capacitor and a TVS tube. The common-mode inductor is electrically connected to the CAN transceiver, and the filter capacitor and the TVS tube are both electrically connected to the common-mode inductor.

8. The communication protocol converter for a generator excitation system according to claim 1, characterized in that: The Ethernet module includes an Ethernet cable interface, a network port transformer and a CH395Q chip, and the Ethernet cable interface is electrically connected to the CH395Q chip through the network port transformer.

9. The communication protocol converter for a generator excitation system according to claim 6, characterized in that: The switch input module includes a switch input interface, an indicator light and an optocoupler, and the indicator light and the optocoupler are both electrically connected to the switch input interface; the switch output module includes a shift register, and the shift register has multiple data input terminals and multiple data output terminals.

10. The communication protocol converter for a generator excitation system according to claim 9, characterized in that: The number of the RS-485 modules is two, the number of the switch input modules is eight, and the number of the switch output modules is forty-eight.

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