A can-bus-based inverter parallel system and its carrier synchronization method

Abstract

The invention discloses an inverter parallel system based on a CAN (controller area network) bus and a carrier synchronization method of the inverter parallel system. The system is characterized by comprising a central monitor, a host and N slaves, wherein the central monitor is used for monitoring working states of the host and the N slaves and can assign a new host when the system has a single-point failure or a multi-point failure; the host is used for sending carrier synchronization signals and monitoring working states of the N slaves; the N slaves are used for receiving the carrier synchronization signals and realizing carrier synchronization and can determine a new host independently when the parallel system has the single-point failure or the multi-point failure. The problem of failure of carrier synchronization when the parallel system has the single-point failure or the multi-point failure can be solved at the system level, and the reliability and the accuracy of carrier synchronization of the parallel system can be improved, so that free switching of modules and high-capacity modular parallel connection can be realized on the premise of carrier synchronization.

Description

technical field [0001] The invention relates to the field of grid-connected inverters, in particular to a CAN bus-based inverter parallel system and a carrier synchronization method thereof. Background technique [0002] In the high-power power electronic modular parallel system, the circulating current problem is the key technology for the reliable parallel operation of inverters. The parallel operation of common AC and DC bus redundant grid-connected inverters is likely to cause circulation problems, which will seriously distort the grid-connected current, increase losses, and reduce system efficiency. Inconsistency factors such as modulating waves and carriers of each module can easily cause module overcurrent and inter-module circulation. For the circulating current problem caused by the parallel operation of grid-connected inverters with this structure, it is generally used to suppress the circulating current by injecting positive and negative sequence currents or adju...

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Problems solved by technology

[0004] The purpose of the present invention is to overcome the deficiencies in the prior art, and provide a CAN bus-based inverter parallel system and its carrier synchronization method with high accuracy and reliability, in order to solve the problem of parallel system occurrence from the system level. The problem that the carrier cannot be synchronized when single-point or multi-point failure improves the reliability and accuracy of the carrier synchronization of the parallel system, so that the free switching of modules and large-capacity modular parallel connection can be realized under the premise of carrier synchronization

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