基于全阶观测器的三电平逆变器异步电机无速度传感器矢量控制系统

Sensorless Vector Control System of Induction Motor Fed by Three-Level Inverter Using a Full Order Observer

采用全阶观测器的方法在三电平逆变器平台上实现了异步电机的无速度传感器矢量控制。针对观测器中增益矩阵选择困难的问题,采用解析推导的方法借助数学软件完整地得出了六组增益矩阵,并指出了采用不同状态变量时增益矩阵之间的联系。全阶观测器只需要两路直流母线电压和两路电机电流信号,可以在全速域范围内准确的观测磁链和转速,并成功的将观测得到的转速和磁链用于闭环矢量控制中。仿真和实验表明基于全阶观测器的矢量控制系统动静态性能良好,对电机参数变化具有较好的鲁棒性。采用预励磁的方法可以在减小起动电流的同时增大起动转矩,保证系统的低速稳定运行。

Speed sensorless vector control of an induction motor fed by three-level inverter is realized based on a full order adaptive flux observer. To solve the problem of gain matrix selection, analytical method is used with the help of mathematical software and six groups of solutions are obtained. Also the relationship between different gain matrixes when the state variables are different is given. Only the upper and the lower DC link voltage and two phases of motor current are needed to observe the flux linkage and rotor speed. The observer exhibits excellent performance in the whole speed range and the estimated speed and flux are used in the close loop control successfully. Simulation and experimental results prove that the observer-based sensorless vector control system has a good performance in steady-state accuracy and dynamic tracking, and it is robust to motor parameter variation. By using pre-excitation, the starting current is reduced while increasing the starting torque, which guarantees working steadily in low speed.