风电和光伏本身固有的间歇性、波动性在规模化并网后会对电网的安全稳定运行带来不利影响。随着风力发电和光伏发电的快速发展，这个问题日益突出，因此大规模电池储能系统相应技术研究十分重要。能量转换系统（power conversion system，PCS）是电池储能系统的一个重要组成部分，分别对PCS的2个组成部分——变流器和滤波器进行比较分析。结合现有电池技术，认为与传统的包含DC/DC和DC/AC环节组成的变流器相比，仅含有DC/AC环节的变流器与由Z源网络和DC/AC环节组成的变流器，具有能量转换效率更高、控制更简单的特点；与传统L滤波器和LC滤波器相比，LCL滤波器可以更好地抑制高次谐波，有效地降低电感的值，提高系统的动态性能，并且受电网的影响较小；提出了2种新的PCS拓扑结构。

After large-scale wind power and photovoltaic power is connected with the grid, the inherent intermittent and volatility of wind power and photovoltaic power may have adversely affects on the security and stability of power grid. With the rapid development of wind power and photovoltaic power generation, this problem is increasingly outstanding. So it is very important to development the technology research of large-scale battery energy storage system (BESS). The article respectively carried out comparative analysis on the converter and the filter, which were the components of power conversion system (PCS) as an important component of BESS. Based on the existing battery technology, the results show that the converter only containing DC/AC link and the converter containing Z-source network and DC/AC link both have the characteristics of higher energy conversion efficiency and simple control, compared with traditional converter which contains DC/DC link and DC/AC link. Compared with the traditional L filter and LC filter, the LCL filter can restrain high harmonics better, effectively reduce the inductance value, improve the dynamic performance of the system, and be less affected by the grid. Combined with analysis conclusion, the article put forward two new topological structures of PCS.