春晨 KGG硅橡胶控制电缆 耐高温控制电缆

江苏春晨电缆有限公司生产KGG硅橡胶控制电缆 ，KGG硅橡胶控制电缆 ，

三相异步电动机的定子铁芯中放置三相结构完全相同的绕组U、V、W，各相绕组在空间上互差120°电角度，如下图所示，向这三相绕组通入对称的三相交流电，如图（b）（c）所示。下面我们以两极电动机为例说明电流在不同时刻时，磁场在空间的位置。

In the stator core of three-phase asynchronous motor, U, V and W windings with identical three-phase structure are placed, and the electrical angles of each phase winding are 120 degrees different in space. As shown in the figure below, symmetrical three-phase alternating current is applied to the three-phase windings, as shown in figure (b) (c). Next, we take the bipolar motor as an example to illustrate the position of magnetic field in space at different time of current.

下图（b）所示，假设电流的瞬时值为正时是从各绕组的首端流入，（用〇中间加个×表示），末端流出（用“⊙”表示），当电流为负值时，于此相反。

As shown in figure (b) below, assuming that the instantaneous value of current is positive, it flows from the first end of each winding (represented by plus in the middle) and from the end (represented by). When the current is negative, the opposite is true.

在ωt=0的瞬间，iu=0，iv为负值，iw为正值，如图（c）所示，则V相电流从V2流进，V1流出，而W相电流从W1流进，W2流出。利用安培右手定则可以确定ωt=0瞬间由三相电流所产生的合成磁场方向，如图（d）①所示。可见这时的合成磁场是一对磁极，磁场方向与纵轴线方向为一致，上方式北极，下方是南极。

At the moment of_t = 0, IU = 0, IV is negative and IW is positive. As shown in figure (c), the V phase current flows in from V2 and out of V1, while the W phase current flows in from W1 and out of W2. The direction of the synthetic magnetic field generated by the three-phase current at the moment of_t=0 can be determined by the ampere right-hand determination, as shown in Fig. (d)1. It can be seen that the composite magnetic field at this time is a pair of magnetic poles, the direction of magnetic field is the same as the direction of the longitudinal axis, the upper Arctic, and the lower Antarctic.

在ωt=π/2时，经过了四分之一周期，iu由零变为最大值，电流由首端U1流入，末端U2流出；iv仍为负值，U相电流方向与（1）时一样；iw也变为负值，W相电流由W1流出，W2流入，其合成磁场方向如图（d）②所示，可见磁场方向已经较ωt=0时按顺时针方向转过90°。

When t = pi/2, after a quarter cycle, IU changes from zero to maximum, current flows from the first U1 to the end U2; IV is still negative, and the direction of U phase current is the same as that of (1); IW also changes to negative, W phase current flows from W1 to W2, and the direction of synthetic magnetic field is shown in figure (d). It can be seen that the direction of magnetic field is already comparable. When_t = 0, turn 90 degrees clockwise.

应用同样的分析方法可画出ωt=π,ωt=2/3*π,ωt=2π时的合成磁场，分别如图（d）③ ④ ⑤ 所示，由图中可明显地看出磁场的方向逐步按顺时针方向旋转，共计转过360°，即旋转了一周。

Using the same analysis method, we can draw the composite magnetic field when_t = pi, _t = 2/3* PI and_t = 2 pi. As shown in Figure (d) and (d) and (4) respectively, it is obvious that the direction of the magnetic field rotates clockwise step by step, totally turning 360 degrees, that is, turning for a week.