摘要
光伏发电直流供电网中,光伏变换器工作于MPPT模式,但当负载变化时,负载功率的需求及直流母线电压的稳定,亦即稳定性协调控制成为电网的主要问题。基于上述问题从系统能量角度分析蓄电池的充放电原理,亦即与蓄电池所连的双向直流变换器的工作模式。提出采用直流母线分层控制来决定双向直流变换器的工作方式,分层控制可以减少双向变换器的工作时间,减少频繁启动,以减小变换器带来的功耗并延长寿命。在双向变换器自动无缝切换问题上,采用逻辑判断法来控制工作模式,实现升压/降压自动切换,并设计低压小功率实验电路进行验证。
In DC power supply based on PV,PV converter operates in MPPT mode.However,in case of load variation,stability coordination control of micro-grid becomes the main problem.In the paper,charging and discharging principle of storage were analyzed according to energy systems aiming to above problem,and the operating mode of bi-directional converter connected with storage was studied.A DC bus hierarchical control was proposed to decide operating mode of bi-directional DC/DC converter.Hierarchical control can reduce the operation hours of bi-directional converter,frequent starting,and the power dissipation,so that to prolong the lifetime of bi-directional converter.On the issue of automatic seamless switching,a logical judgment method was adopted to control its operating mode.The method can realize automatic switching between boost and buck.Finally,a low voltage small power experiment circuit was designed for testing.
出处
《计算机仿真》
北大核心
2017年第3期114-117,193,共5页
Computer Simulation
基金
山西省煤基重点科技攻关项目(省级重点)(MD2014-06)
