基于SEDC和SSDC抑制HVDC系统SSO的研究

摘要

Based on AC-DC system, additional excitation damping controller design (SEDC) and sub-synchronous damping controller (SSDC) are designed by the same design principles, and the two controllers compensate the electrical damping of shaft natural oscillation frequency.Using the test signal method, their abilities to compensate electrical damping are compared, and the results are verified using time domain simulation.The results show that the SSDC can provide greater electrical damping than SEDC at compensation point, and inhibit the SSO more effectively.A qualitative physical explanation is provided for the results.Taking SEDC as object to be investigated, the influences of parameters on the inhibition of SSO are studied.The electrical damping can be enhanced by increasing the gain of SEDC, but the nearby damping is shifted.The gain's positive role of inhibiting SSO will appear when the natural oscillation frequency is stable.Setting appropriate parameters of SEDC, such as filter quality factor and order, is required for increasing the positive electrical damping of the natural oscillation frequency.%基于交直流系统按相同的设计原理设计了附加励磁阻尼控制器(SEDC)和次同步阻尼控制器(SSDC),采用测试信号法比较了两者对于轴系自然扭振频率处电气阻尼的补偿能力,用时域仿真的方法验证了比较的结果.结果表明:SSDC比SEDC在补偿点处能提供更大的电气阻尼,从而更利于抑制SSO.对此结果进行了定性的物理解释.以SEDC为研究对象,分析了其参数对抑制SSO的影响.SEDC放大倍数的电气阻尼补偿具有阻尼转移现象,只有在次同步振荡自然扭振频率不偏移的条件下才能发挥提高放大倍数对于抑制SSO的正面作用.对附加阻尼控制器设置适当的滤波器品质因数和阶数参数才能在固有振荡频率处有明显的正阻尼.