The Research of Parallel Current-sharing for Modular High-power DC Power Supply
|School||Hebei University of Technology|
|Course||Communication and Information System|
|Keywords||switching power supply modular parallel current-sharing decoupling control state space robustness|
Compared with the traditional linear power supplies, the switching power supply is moreefficient, more smaller and more lighter, so it is widely used around the world. With the switchpower supply into the rapid development of the new period, a variety of new technologiesemerging, and the most prominent manifestation of the switching power supply is modular. Fortoday’s electronic power learning, a major field of study is the research and development ofhigh-power switching power supply, and also derives out many unprecedented researchdirections, including the critical technology for large power supply system-parallelcurrent-sharing technology of the switching power supply.For the high power supply composed of multiple power modules in parallel, when theoutput load change occurs, the output current of the system should be kept constant. Firstly, thispaper introduces the principle of parallel current-sharing, and then analyzes the commoncurrent-sharing methods, points out that the traditional current-sharing methods are inadequate,finally puts forward a new current-sharing method. The new current-sharing method not only canrealize current-sharing fast, but also can realize constant current output.The coupling between the parallel power module is the key problems of the parallelcurrent-sharing control to solve.Usually,every module needs to consider uniformly and conductcontrol regulation simultaneously, in order to achieve the purpose of current-sharing. It is hard tocontrol if the system demands high dynamic characteristics. And decoupling control caneliminate the coupling relationship between the each module by the decoupling method, thenrealizes the independence control of each module, reduces the difficulty of designing controlsystem and adjusting greatly.In order to verify the correctness of theory analysis,this paper models the modular parallelpower system with the state space method, then designs the decoupling control system by usingdiagonal matrix decoupling method, and finally uses SIMULINK to test the decoupling performance, dynamic current-sharing performance, tracking performance and robustness ofcurrent-sharing control system adding the decoupling control. The simulation results show thatthe current-sharing control system not only can realize stable static current-sharing control,butalso has a good dynamic response characteristics.