Current sharing technology in parallel operation of inverters

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Current sharing technology in parallel operation of inverters [Copy link]

The capacity of a single power supply component is limited. In order to increase the capacity of the power supply and improve the reliability of power supply, power supply parallel connection technology is often used. For example, if 50 power supplies are connected in parallel, even if several of them fail, the normal operation of the entire system will not be affected due to the redundancy of the power supply system. Parallel connection technology can also be used to achieve large-capacity inverter power supplies. Since inverter power supplies usually use new fully controlled power switching devices to form unit modules, the capacity of a single inverter power supply module is very limited due to the capacity of the power switching devices. By connecting multiple modules in parallel to expand the capacity, not only can the advantages of new fully controlled power switching devices be fully utilized, the system volume can be reduced, and the noise can be reduced, but also the dynamic response speed of the system and the versatility of the inverter converter can be improved.

However, the parallel operation of AC power supplies is much more complicated than the parallel operation of DC power supplies. It requires not only that the output voltage amplitudes of the two power supplies are equal, but also that their frequencies and phases are strictly consistent. In order to make each parallel module work reliably, the most important thing is to solve the current sharing problem. This article analyzes the generation of circulating current and introduces several methods to solve the current sharing problem.