| Inverter is one kind of power electronic devices which transform direct current to alternating current. Inverter is widely using in electrical and electronic devices. While inverter play a important role in uninterrupted power supply, frequency converter, rail transit system. In today's society energy problem is increasingly prominent, so inverter has become the research focus in the field of the industry, the commerce, the civil and etc.With the developing of the power electronics, we make the integrated and modular requirements of inverter.Then the integration of IGBT power module appears, even more frequency converter module appears. Based on the power module I built the inverter modules system, then analyse the characteristics and advantages of the inverter modules system. Analysis and compare are put into the filter circuits, whose output amplitude frequency characteristics and phase frequency characteristics are mentioned in this paper, then their features are summarized.Various capacity of topological can be built based on the inverter modules. This paper takes the topological combined with cascading and paralleling as an example to study and analyze. This method improves the capacity and redundancy of the inverter, having certain application prospect. Simulation results show that the system using double closed-loop control strategy can output high quality waveforms.The circulating current analysis is given in the inverter parallel system isolated by transformers.The reason causes circulating current is analyzed based on mathematical model. Uniform modulation and other two control strategies are presented to these parallel system. Finally, experiments are given to verificate the theoretical analysis. |
