现代电子技术

针对当前滑模观测器在控制频率与电机基波电流频率比值较低的低载波比工况下，观测误差较大、甚至引发电机失步的问题，提出一种基于复矢量滑模观测器和速度前馈正交锁相环的无感控制算法，以提高低载波比工况下无感观测的准确性。针对反电动势观测稳定性问题，提出一种增益闭环调节的复矢量滑模观测器，采用复矢量建模方式替代传统标量建模方法，有效抑制低载波比工况下因耦合增强导致的观测不稳定现象；针对无感位置检测精度低的问题，提出一种速度前馈正交锁相环算法，利用反电动势观测值构造速度前馈项以提高无感速度估算的响应速度，并将算法中得到的电机速度估算值作为反馈用于解耦，从而获取反电动势观测值中的转子角度正余弦值，提高电机无感位置检测的精度。实验结果表明，所提算法不仅在低载波比工况下具有较好的观测性能，在载波比不足的极限工况下也能够实现稳定观测。该算法有助于解决高基频运行下因载波比下降而引发的无感估算问题，具有一定的工程应用价值。

In allusion to the issue that the current sliding mode observer has large observation errors and even causes motor out⁃of⁃step under low carrier ratio conditions where the ratio of control frequency to motor fundamental current frequency is low, a sensorless control algorithm based on complex vector sliding mode observer and speed feedforward quadrature phase⁃locked loop (PLL) is proposed to improve the accuracy of sensorless observation under low carrier ratio conditions. For the back electromotive force (back⁃EMF) observation stability, a complex vector sliding mode observer with gain closed⁃loop regulation is proposed, which uses the complex vector modeling approach instead of the traditional scalar modeling method, effectively suppressing the observation instability caused by enhanced coupling under low carrier ratio conditions. In allusion to the issue of low precision in sensorless position detection, a speed feedforward orthogonal PLL algorithm is proposed. In this algorithm, the observed back electromotive force is used to construct the speed feedforward term, thereby improving the response speed of sensorless speed estimation. The estimated motor speed obtained from the algorithm is used as feedback for decoupling, so as to obtain the sine and cosine values of the rotor angle from the observed back electromotive force, and enhance the precision of sensorless position detection for the motor. The experimental results show that the proposed algorithm not only has good observation performance under the condition of low carrier ratio, but also can achieve stable observation under the extreme condition of insufficient carrier ratio. The proposed algorithm is helpful to solve the sensorless estimation problem caused by the decrease of carrier ratio under high fundamental frequency operation, and has a certain engineering application value.