中文摘要：

将逆变器模拟为同步发电机的特性,可提升电网对分布式电源的接纳能力,然而同步逆变器在并网瞬间存在较大的冲击电流,为此,提出了一种预同步并网方法。首先介绍了同步逆变器的原理,并分析其并网过程存在的问题,在此基础上提出了预同步的并网方法并介绍锁相环的设计,同时也对主电路和控制参数进行了设计。最后通过10 k W的原理样机进行实验验证,实验结果验证了所提方法的有效性。

英文摘要：

The power grid＇s ability of accepting distributed generation（DG） can be lifted by mimicking the grid-connected inverter as synchronous generator,however there is a larger impulse current at the grid-connecting moment of synchronverter,for this reason,a pre-synchronization method for grid-connection is proposed.Firstly,the principle of synchronverter is presented and the existing troubles during its grid-connection are analyzed.On this basis,a pre-synchronization method for grid-connection is given and the design of phase-lock loop is described,meanwhile the design of the main circuit and control parameters are presented.Finally,experimental verification of the proposed method is performed by a prototype with the capacity of 10 kW and experimental results show that the proposed method is effective.