六脉波双变量交交变频工频调压闭环研究

Study on 6-pulse Double-Variable Cross-Frequency Control Power Frequency Regulator Closed-loop

在基于六脉波双变量交交变频基础上,为了避免电机在软启动过程中由变频段(低于50HZ)向工频(50 HZ)调压段切换时因频率极差较大而导致的机械特性变软,提高电机起动至共频段转速的控制性能,抑制由37.5 HZ向50 HZ切换时引起的瞬时冲击电流,以满足工业控制对调速精度的要求。通过采用增量式PID控制算法对调压时间常数进行控制,将调压时间常数偏移量作为控制量形成闭环,实现闭环调节。大量的仿真与实验结果均表明在闭环调节的作用下,电机转速超调量较小,几乎可以无静差的稳定运行于1400 r/min,实现了由变频段向工频调压段切换时的软过度。

Based on the six-pulse bivariate cross-converter based on, in order to avoid the motor in the soft startprocess from the variable frequency band （below 50 HZ） to the power frequency （50 HZ） voltage regulator section when the frequency difference caused by the larger The mechanical properties are softened, which improves the control performance of the motor starting to the common-band rotation speed, and suppresses the instantaneous inrush current caused when switching from 37.5 HZ to 50 HZ,so as to meet the requirements of the industrialcontrol on the speed regulation accuracy. Through the use of incremental PID control algorithm to control the time constant of pressure regulation, the pressure control time constant offset is used as a control quantity to form aclosed loop, and closed-loop adjustment is realized. A large number of simulation and experimental results show thatunder the effect of closed-loop regulation, the overshoot of the motor speed is small, and it can be operated with stability of almost no static difference at 1400 r/min, and the switching from the variable frequency band to the power frequency voltage regulation section is realized. Soft over.