静止式中频电源组网系统模式切换暂态过程控制

Control of Mode Conversion Transient Process of Medium Frequency Solid-State Power Supply

静止式中频电源组网系统模式切换暂态控制对于整个系统的稳定运行有着至关重要的作用。为此,分析了静止式中频电源组网过程中带与不带本地负载时组网、独立运行的原理,并以此为基础,深入研究开关顺序对组网系统模式切换暂态过程的影响,得出组网时模式开关先闭合、脱网时静态开关先分断为最优开关顺序的结论;同时,为了保证组网单元在组网和脱网过程中以较小的电流冲击实现模式切换的平稳过渡,提出一种静止式中频电源组网系统模式切换平滑控制策略,即通过电流峰值的平均分配及峰值、相位的平滑调节,实现从机单元的无冲击并网,并给出具体实施步骤。仿真和实验结果证明了模式切换暂态过程理论分析的正确性及平滑控制的有效性。

The mode conversion transient process is very important to the 400 Hz solid-state power supply integration system. For this reason, this paper analyzes the principle of network building, its independent operation with or without local loads during the integration process, and the effects of different switching sequences on mode conversion transient process. The conclusion is that the mode switch（MS） must turn on before the solid-state switch（SSS） at the on-grid state, while the SSS must turn off before the MS at the off-grid state. Therefore, a strategy of smooth control for the system which includes some concrete steps is proposed. It can achieve grid connection without shock by the average distribution of peak currents and smooth the adjustments of peak current and phase. Case study has verified the method for smooth control.