矿用大功率装备全数字变频调速节能设备研发

传统有限控制集模型预测控制(FCS-MPC)存在开关频率不固定,采样频率过高等缺点,造成PWM整流器功率脉动较大;而交直交变频器前端采用三相脉宽调制整流器,可有效提高金属矿山球磨机等大功率设备的电能利用效率。三相电压型PWM整流器采用固定开关频率模型预测电流控制(MPCC-CSF),通过评价函数优化算法得到期望电压矢量来代替FCS-MPC中8个离散的电压矢量,增加了系统控制集的覆盖范围。首先,构建包含电流偏差的评价函数;然后,将数学上的二分法思想引入到评价函数中,迭代寻优得到期望电压矢量的幅值和相位,为了提高寻优效率,利用电网电压矢量构建虚拟扇区,缩小寻优范围;最后,结合脉宽调制(SVPWM)技术输出最优开关状态。对所提MPCC-CSF策略与传统的FCS-MPC方法进行的可行性和优越性的仿真和试验对比分析表明,MPCCCSF方法较传统FCS-MPC方法具有控制精度高等优点。

Research and Development of Full-digital Frequency Control Energy Saving Device for Mine Large Power Equipment

Switching frequency is not fixed and the sampling is too high for PWM rectifiers using traditional Finite Con-trol Set Model Predictive Control ( FCS-MPC) . Model Predictive Current Control with Constant Switching Frequency ( MPCC-CSF) of three-phase voltage PWM rectifier brought the AC frequency control device can effectively improve the power utiliza-tion efficiency of large power equipment. The control set was expanded by the expected voltage vector that obtained by the eval-uation function optimization algorithm to replace the eight discrete vectors in FCS-MPC. First of all,the proposed algorithm build the evaluation function which containing the deviation of the current and thenthe mathematical idea of dichotomy is intro-duced into the evaluation function,and the amplitude and phase of the expected voltage vector are obtained by iterative optimi-zation. In order to improve the optimization efficiency and reduce the optimal range,the virtual sector is constructed by the grid voltage vector. Finally,the proposed algorithm combined with the space vector pulse width modulation ( SVPWM) technology output the optimal switching state. In order to verify the feasibility and superiority of the proposed MPCC-CSF strategy,a com-parative analysis between the traditional FCS-MPC and the proposed MPCC-CSF was done by simulations and experiments. And a further summarization was performed to derive the advantages of MPCC-CSF.