双转子汽轮机采用行星齿轮连接耦合其内、外转子实现功率传递，相对于传统单转子能够有效降低最高工作转速，获得良好的动力学性能。以一种含行星齿轮连接条件的对转双转子系统为研究对象，基于MASTA内置算法，计算了行星齿轮传递误差、时变啮合刚度，建立考虑行星齿轮实际啮合过程的内、外转子耦合动力学模型，并对该模型的固有特性和不平衡响应等开展了计算分析。结果发现：双转子系统前两阶固有频率相对于主激励的单转子固有频率提高超过10%。振型包括了内转子主激励、外转子主激励以及内外转子耦合振型。通过谐响应法对内、外转子不平衡响应进行计算，得到支承轴承处内、外转子分别单独激励时的升转速扫频曲线以及工作状态下振动响应频谱图，发现转子振动通过行星齿轮传递会产生衰减。对比相同体积、相同功率输出的单、双转子振动响应，发现双转子结构振动幅值在X、Y方向分别降低为单转子的24.4%、39.7%，双转子系统具有更好的动力学性能。该研究可为含行星齿轮连接条件的对转双转子系统振动噪声控制提供技术支撑。

The double rotor steam turbine uses planetary gears to connect and couple its inner and outer rotors to achieve power transmission. Compared with the traditional single rotor, it can effectively reduce the maximum working speed and obtain better dynamic performance. In this paper, a counter rotating dual rotor system with planetary gear connection conditions is taken as the research object. Based on the MASTA built-in algorithm, the planetary gear transmission error and time-varying meshing stiffness are calculated, and the inner and outer rotor coupling dynamic model considering the actual meshing process of planetary gears is established. The inherent characteristics and unbalanced response of the model are calculated and analyzed. The results show that the natural frequencies of the first and second order of the dual rotor system are more than 10% higher than that of the single rotor under the main excitation.The vibration modes include the main excitation of the inner rotor, the main excitation of the outer rotor and the coupling vibration modes of the inner and outer rotors. The harmonic response method was used to calculate the unbalance response of the inner and outer rotors, and the frequency sweep curve of the rising speed and the vibration response spectrum under the working state were obtained when the inner and outer rotors at the support bearing were separately excited. It was found that the vibration of the rotor would be attenuated when transmitted through the planetary gear. In the study, comparing the vibration responses of single and double rotors with the same volume and power output, it is found that the vibration amplitude of the double rotor structure in the X and Y directions is reduced to 24.4% and 39.7% of that of the single rotor, respectively. The double rotor system has better dynamic performance. The research can provide technical support for vibration and noise control of counter rotating dual rotor system with planetary gear connection conditions.