中文摘要：

由于波浪的波动性和随机性,直驱式波浪发电系统的输出功率时刻波动.为满足并网要求,必须对输出功率进行平滑控制.将储能系统应用于波电输出功率平滑,选择具有响应速度快、循环寿命长特点的超级电容器储能系统,提出了2种功率平滑控制策略：一种基于低通滤波原理,通过滤除输出功率中的高频分量来平滑波动;另一种基于波电功率预测技术,滚动预测输出平均功率,克服了传统方法中平均功率难以获取的缺点.通过在理想波浪和实际波浪条件下的仿真,验证了所提出策略的有效性.

英文摘要：

The randomness and fluctuation of wave cause the fluctuation of output power of the direct-drive wave ener- gy conversion system （DDWECS）. The output power has to be smoothed in order to satisfy the grid-connected require- ments. In this paper, the energy storage system （ESS）is introduced to smooth the output power of DDWECS, and ultra capacitor energy storage system is selected because of fast response times and long cycle life. Two smoothing strategies are proposed： one is based on tow-pass filtering methods, output power is smoothed by filtering the high frequency components; the other is based on output power prediction of wave generation, predicted average output power is ob- tained constantly, which overcomes disadvantages of traditional method. The simulations are carried out under the reg- ular and irregular waves to test the effectiveness of the proposed strategies.