Failure processing method and frequency converter multi-machine primary-and-secondary control system

Abstract

The invention discloses a failure processing method and a frequency converter multi-machine primary-and-secondary control system. The failure processing method comprises the steps that a primary frequency converter is switched to be in a failure state and sends a main machine switching order through a fourth sending terminal when the primary frequency converter is in failure, and the primary frequency converter forwards command words and/or data words through the fourth sending terminal, wherein the command words and/or the data words are received by the primary frequency converter through a fourth receiving terminal and are from a second secondary frequency converter; a fifth secondary frequency converter which meets agent requirements of the primary frequency converter is switched to be an agent primary frequency converter after the fifth secondary frequency converter receives the main machine switching order, wherein the agent primary frequency converter carries out operation according to operating parameters before the failure of the primary frequency converter, and the fifth secondary frequency converter is one of a first secondary frequency converter, a second secondary frequency converter and N third secondary frequency converters. According to the technical scheme, the failure processing method and the frequency converter multi-machine primary-and-secondary control system are beneficial to improving stable reliability of a frequency converter system.

Description

technical field [0001] The present invention mainly relates to the technical field of power electronics, and in particular to a fault handling method and a multi-machine master-slave control system for frequency converters. Background technique [0002] In the frequency converter master-slave control system, the products on the market at this stage are mainly based on the RS485 bus communication method for the design of the communication between the master and slave machines. The structure of the 485 bus communication method is as follows: figure 1 As shown, the console transmits the system operating frequency to each inverter through the 485 bus, and each inverter transmits the status feedback information to the console through the bus. In addition, the system start-stop signal given by the console and the torque signal sent from the main inverter to the slave inverter are all realized through separate hard-wired connections. The problem of this method in the field applic...

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Problems solved by technology

The problem of this method in field application is that the wiring of various control lines is complicated, and the wiring of the serial bus is too long

[0003] In the process of research and practice, the inventor found that the existing inverter system has some defects in the application of dual-machine and multi-machine master-slave control: the communication mode of 485 bus has weak anti-interference in the communication mode between master and slave machines , the disadvantage of poor signal transmission stability

Due to the limitations of communication methods, it is difficult to carry out ultra-long-distance signal transmission

Moreover, the control structure of the master-slave system is complex, multiple signal lines work at the same time, and the installation and operation are cumbersome

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