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全控器件励磁系统不仅具有常规励磁系统的控制功能，还能够在网侧对系统补偿无功，为发电机提供更多阻尼，从而改善系统的阻尼特性，但随着控制变量的增加和系统结构的变化，使得整个系统变的更加复杂，控制系统的设计难度加大。针对这种复杂的非线性系统，首先分析网侧无功补偿与网侧并联等效阻抗的一致性，并在此基础上推导基于三阶同步发电机模型的全控器件励磁系统的等效模型。以控制转子功角和机端电压稳定为目标，采用多变量反馈线性化方法设计基于此等效模型的两输入两输出非线性控制策略。仿真结果表明，相对于线性控制(电压自动调节器+电力系统稳定器)方法，所提非线性控制策略在系统受到大干扰的情况下，依然能较好地增强系统阻尼，并且随着补偿容量的提高，阻尼效果更好；当系统参数发生改变时，依然具有良好的控制效果，相比线性控制适应性更好。“,” Excitation system based on full controlled devices converter, with the ability of ordinary excitation system, can also supply more damping to the synchronous generator and increase the stability of power system through injecting reactive current to the grid. But as the incensement of variables and the change of the system structure, the whole system becomes more complicated and it is harder to design the control scheme. For this complicated nonlinear system, this paper first proved that compensating reactive power in grid side is equivalent to compensating shunt impendence. Based on this conclusion, this paper deduced a third-order model of this kind of excitation system. And with the main goal of controlling the rotor angle as well as the terminal voltage, a MIMO nonlinear control strategy was designed based on this model. The simulation results show that, compared with the linear control scheme (AVR+PSS), this nonlinear scheme is more effective in enhancing the system’s damping, and better effect can be achieved with the compensation capacity increasing; even if system parameters are changed, the good performance and better suitability can be maintained.