A high-precision distributed inverter synchronous control communication system

Abstract

The present invention provides a high-precision distributed frequency converter synchronous control communication system, and constructs the network sites where all distributed frequency converters are located into a positive and negative bidirectional ring communication network, and each station calculates the transmission delay by sending network test data to adjacent stations ;Set one of the network stations as the master station, assign the station number, and establish a communication master-slave network; the master station configures the time chain table, and the slave station calculates compensation parameters; device, and then complete the control cycle and synchronization cycle of the communication system.

Description

Technical field[0001]The invention relates to a synchronous communication system, in particular to a high-precision distributed frequency converter synchronous control communication system.Background technique[0002]With the development of modern industry, the application performance of high-power multi-machine linkage systems is constantly improving. For a multi-motor speed control system controlled by distributed inverters, synchronization between inverters is the key to improving control performance. Take a belt-connected multi-motor system as an example, such as heavy-load synchronous start, power output balance control, etc.; the inverter connected to each motor is provided with synchronization signals and shared control commands by communication cables.[0003]In conventional multi-machine control, taking the typical CAN bus as an example, most MCU chips have integrated CAN controllers, and the application cost is low. The bus-type connection can achieve relatively high synchroni...

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Problems solved by technology

[0003] In the conventional multi-machine control, taking the typical CAN bus as an example, most MCU chips have integrated CAN controllers, the application cost is low, and the bus connection can achieve relatively high synchronization. The delay needs to be manually measured and calculated, and then input into the software; the disadvantage is that the frame length specified in the CAN protocol standard is uncertain, the communication delay is uncertain, and the communication distance is inversely proportional to the speed, which determines the synchronization and real-time performance of CAN bus communication. It is not ideal for places with high performance requirements

[0004] Relying on the typical representative EtherCat protocol of ring series topology communication, it is an open-architecture fieldbus system based on 100M Ethernet. The protocol stipulates that the slave station detects the time difference of data loopback, which is used to eliminate the clock skew of sub-equipment, and can achieve relatively high The disadvantage is that the frame of the Ethernet standard protocol is more complex, and the development is difficult. In the application of a small data volume system, the efficiency is low under the same baud rate and cannot respond in real time; at the same time, the EtherCat protocol requires a dedicated substation, which cannot Realize the flexible conversion of the master-slave station, and the cost of the sub-station module is still relatively high

[0005] In summary, it is suitable for the synchronous control process of distributed frequency converters, and it is necessary to provide real-time, synchronous, flexible, and low-cost communication protocols at the same time. The existing communication protocols cannot meet the requirements.

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