论文部分内容阅读
针对航空变换器在负载短路时需要输出3倍额定电流的要求,提出了一种适用于航空DC/DC变换器短路限流的控制策略。在传统电压-电流双环控制DC/DC变换器的基础上,引入输出电压前馈控制,即将输出电压作为前馈信号,与电流控制器的输出信号相加共同作为调制信号与三角载波交截。通过合理设计前馈系数,保证电流控制器的输出电压在负载短路前后基本保持不变,旁路了PI补偿网络的延时影响,使得短路瞬间占空比即时修正,有效抑制了短路瞬间的电流冲击。小信号建模分析表明,输出电压前馈的引入基本不会影响原双环控制系统的稳态和动态性能。仿真和实验均验证了该控制策略的有效性。
Aiming at the requirement of 3 times of rated current output of aviation converter when the load is short-circuited, a control strategy suitable for short-circuit current limiting of aviation DC / DC converter is proposed. On the basis of the traditional voltage-current double loop control DC / DC converter, the output voltage feedforward control is introduced. The output voltage is used as the feedforward signal, which is added with the output signal of the current controller to make the modulation signal and the triangular carrier intercept. By reasonably designing the feedforward coefficient, the output voltage of the current controller can be kept substantially unchanged before and after the load short-circuit, and the delay effect of the PI compensation network is bypassed so that the duty cycle of the short-circuit moment is corrected instantaneously, effectively curbing the short-circuit current Impact. Small signal modeling analysis shows that the introduction of output voltage feed forward basically does not affect the steady state and dynamic performance of the original double loop control system. Simulation and experiment verify the effectiveness of this control strategy.