The Inverter Optimal Design And Synchronization Control

Uninterruptible power supply (UPS) provide a stable, continuous, uninterrupted power supply, widely used in the power supply as well as power outage protection of critical load. The inverter is an important part of the UPS system, the performance of the inverter will directly affect the overall performance of the UPS system.When UPS system fails and recoveries from fault, it will switch between the inverter operation and grid operation, in order to realize uninterrupted power supply to the load and without too large inrush current, it needs to ensure that the UPS inverter output is synchronized with the grid. When there is no transformer isolation in UPS inverter output, to avoid the DC circulation system is too large, it tends to limit the inverter output DC drift voltage to avoid the DC circulation too large.This paper focuses on the synchronous control of the inverter output with power grid and the inverter output the DC drift voltage suppression. The output phase is able to track the instruction phase by introducing a feedback control of the output voltage phase. Adding the DC drift voltage control loop can effectively reduce the inverter output DC offset voltage. A30kVA three-level inverter is developed on the basis of the above study, and the control method described above is verified on the platform. Experimental results show that the control method is able to achieve the inverter output with the grid synchronization as well as the suppression of the DC drift of the inverter output voltage.In order to reduce the volume of the inverter system, this paper theoretically derives inverter cooling system design, providing theoretical guidance for the thermal design of the inverter. Finally, the test of the three-level IGBT module provided by a company is been done, getting the loss of the three-level IGBT module data.