Research On Parallel Operation Of Three-phase Inverters Based On CAN Bus

As the shortage of energy and the requirement of high quality and reliability power supply increasing, the technology of parallel operation of inverters is widely used with fast development. In the operation of inverters, the most important problem is how to limit the circulating current between paralleled inverters and make the modules synchronized finally. The traditional method is proved that it can't meet the needs. As the operational speed of DSP(Digital Signal Processor)grow more and more fast, application of DSP in parallel inverters has been more popular.On the basis of comparison of control scheme of parallel inverters, this paper proposes a method to bring in the hot CAN Bus in industrial automation fields, which realized the distributed control, makes the system more smart and improves the reliability in practice as well. After researching and analyzing the mathematical model of single three-phase inverter, a single three-phase inverter is designed for parallel operation basing on SVPWN modulation and closed-loop control on voltage. In the research about the technology of parallel operation, the characteristic of circulating current, closed-loop voltage and power is emphasized and a scheme of power sharing basing on CAN Bus is proposed. The simulation result shows this policy is effective for the parallel system. The circuit of CAN's interface and corresponding communication module is designed based on DSP for the parallel system, which ensures the integrality and the real-time transmission of important data during the parallel operation. Under the platform of TMS320LF2407, detail of hardware and software are provided in the paper. Additionally, the key arithmetic are carried out on MATLAB software and the waveforms of simulation are given.