The modulating signals of firing delay angle at the rectifier and firing lead angle at the inverter , and the excitation voltage are chosen to be control variables . the offset of the current of dc line and the extinction angle and the power angle of generator are chosen to be control outputs . then a nonlinear controller is designed for the system under study according to direct feedback linearization theory 以整流侧触发延迟角的调节信号、逆变侧触发超前角的调节信号以及发电机励磁电压作为控制变量,以直流线路电流、逆变侧关断角以及发电机功角的偏移量作为目标输出,用直接反馈线性化方法设计了系统的非线性控制器。