永磁同步电机无位置传感器带速启动研究

针对无位置传感器永磁同步电机在带速状态下无法可靠启动的问题,通过向逆变器施加两个短时零电压矢量的方式,使电机定子三相绕组短路,根据短路电流相量在αβ坐标系下的角度变化,辨识出电机转向和转速,通过对短路电流在dq坐标系下暂态过程的解析分析,估算出电机转子位置,给出了暂态过程中短路电流幅值大小与初始转速和短路时间之间的关系,提出了具体的带速启动实现方案。在TI公司的TMS320F28027作为主控芯片的驱动系统以及带风机负载的550 W永磁同步电机组成的实验平台上对带速启动方案进行了评价,进行永磁同步电机在不同转速和短路时间情况下的带速启动实验。研究结果表明:设计的带速启动方案能够准确的根据短路电流判断出电机启动瞬间的转向、转速和转子位置,从而保证了永磁同步电机在带速状态下的可靠启动。

Start method for PMSM without position sensor in rotating conditions

Aiming at the matter that permanent magnet synchronous machine ( PMSM) with no position sensor cannot start reliably in rotating conditions, two zero-vectors were applied to inverter to make three phase stator windings of the machine had a short-circuit. Through analy-zing the angle variation of the currents in αβ coordinates, the rotational direction and speed of the machine were derived. Furthermore, through analyzing the transient state process of the currents in dq coordinates, the rotor position of the machine was estimated, the relation-ship between the initial speed, the duration of short-circuit and the amplitude of short-circuit current was put out, a start method for PMSM in rotating conditions was offered specifically. The start method mentioned above was evaluated on the experimental platform, which TMS320F28027 provided by TI was used as the master of the whole control system, and a fan was used as the load of PMSM, whose rated power is 550W, the start method was tested under different initial speed and duration of short-circuit conditions. The experimental results show that according to short-circuit currents, the start method designed, can estimate the rotation direction, initial speed and rotor position precisely, thus reliable start of PMSM in rotating conditions can be achieved.