六脉波双变量交交变频调速系统最佳压频比控制策略研究

发布时间：2018-05-16 13:46

本文选题：双变量 + 在线连续　；参考：《河南理工大学》2015年硕士论文

【摘要】：异步电动机带载运行时,特别是轻载运行时,为了保持电机的磁通恒定不变,传统上采用的电压频率协调控制方式是恒压频比控制。但恒压频比控制更多是从电机自身来考虑问题的,没有考虑电机具体的工作条件,比如负载特性,电压等级等,没有使交交变频器与异步电动机的工作状况更好的进行匹配,致使异步电动机的力能指标,比如功率因数和效率并没有达到最优,没有实现节能的目的。因此,本文提出了最佳压频比控制策略,并结合交交变频器在线实时连续变频控制算法使电机始终运行在综合力能指标较高的经济状态。首先,在传统的用余弦交点法离线计算触发时刻,以查表方式实现对晶闸管脉冲触发的基础上,提出了基于双变量控制理论的交交变频器在线实时连续变频控制策略,圆满的解决了晶闸管脉冲触发时刻实时计算的问题,实现了交交变频器输出频率的实时连续变化。其次,构建了Matlab仿真模型,分别对同一电机在不同频率下带负载时的情况以及不同电机带负载时的情况进行了对比仿真研究。通过大量的仿真总结出了电机的效率和功率因数随压频比变化的一般规律,找到了使电机的综合力能指标最优的最佳压频比值。最后,通过具体的实验,验证了仿真结论,并结合交交变频器在线实时连续变频控制策略实现了最佳压频比在线连续变频,使异步电动机始终以较高的力能指标经济运行。
[Abstract]:In order to keep the flux constant when the asynchronous motor is in operation with load, especially in the light load, the traditional voltage frequency coordinated control is constant voltage frequency ratio control. But the constant voltage frequency ratio control is more from the motor itself, not considering the specific working conditions of the motor, such as load characteristics, voltage grade, and so on, did not make the AC-AC converter and the asynchronous motor work better matching. As a result, the force and energy index of asynchronous motor, such as power factor and efficiency, is not optimal, and the purpose of energy saving is not realized. Therefore, this paper puts forward the optimal control strategy of pressure-frequency ratio, and combines with AC-AC frequency converter on-line real-time continuous frequency conversion control algorithm to make the motor always run in the economic state of high comprehensive force and energy index. Firstly, based on the traditional off-line calculation of trigger time using cosine intersection method and the realization of thyristor pulse trigger by table lookup, an on-line real-time continuous frequency conversion control strategy for AC / AC converter based on the bivariate control theory is proposed. The real-time calculation of the trigger time of thyristor pulse is solved successfully, and the output frequency of AC / AC converter is changed continuously in real time. Secondly, the Matlab simulation model is constructed, and the case of the same motor with load at different frequency and the case of different motor with load are compared and simulated respectively. Through a large number of simulations, the general law of the motor efficiency and power factor changing with the voltage frequency ratio is summarized, and the optimum voltage frequency ratio is found to make the comprehensive force and energy index of the motor optimal. Finally, through the concrete experiment, the simulation conclusion is verified, and combined with the AC-AC converter on-line real-time continuous frequency conversion control strategy, the optimal voltage frequency ratio on-line continuous frequency conversion is realized, which makes the asynchronous motor always run economically with higher force and energy index.
【学位授予单位】：河南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM921.51;TM343

【相似文献】