一种新型的次同步扭振测量方法

提出一种基于交流励磁机三相电压信号测量扭振瞬时转速的方法，讨论了扭振测量方法的动态特性，利用三相电压的对称关系将电压取样信号3倍频，使测量方法具有较好的动态性能。对因三相电枢绕组位置不对称引起的误差进行了讨论，并给出了校正方法。所提出的扭振测量方法无需加装转速敏感元件，便于实现，且对转子胀差和横向振动的影响不敏感。

A NEW METHOD FOR MEASURING SUBSYNCHRONOUS OSCILLATION

A new m ethod for measuring the instantaneous speed during subsynchronous oscillation SSO by using the three- phase voltages of AC exciter is proposed. The dynam ic features of this m easuring m ethod are discussed. By em ploying the sym metrical relationship of the three- phase voltages,the voltage signals are tripled such that some better dynam ic characteristics can be obtained.The error stemm ed from the asym metry of the three- phase armature windings of the AC exciter is discussed and the corresponding correction m ethod is presented. This proposed method needs not any additional speed sensor and hence is convenient for implementation.Moreover,it is insensitive to the transverse vibration and the differential expansion of the rotor.