3Y接线是什么含义、 发电机为何多采用旱形接线? What does 3Y wiring mean and why do generators often use dry wiring?

在发电机铭牌或图纸中，我们常见到发电机定子绕组的接线方式表示为Y,3 Y,5 Y等。这表示发电机是按星形方式接线。Y3表示发电机定子绕组是3路星形并联,也可以理解为3个星形接线的发电机组并联在一起。由于发电机的磁通内有较强的3次谐波,如果发电机接成△线，则3次谐波会在△内形成回路，造成附加的损耗和发热。因此发电机定子绕组一般接成Y形使3次谐波不能形成回路。

In the nameplate or drawing of the generator, we commonly see that the wiring of the generator stator winding is represented as Y, 3 Y, 5 Y, etc. This indicates that the generator is wired in a star configuration. Y3 represents that the stator winding of the generator is connected in parallel with three star shaped wires, which can also be understood as a generator with three star shaped connections connected in parallel together. Due to the strong 3rd harmonic in the magnetic flux of the generator, if the generator is connected to a delta line, the 3rd harmonic will form a loop within delta, causing additional losses and heat generation. Therefore, the stator winding of the generator is generally connected in a Y-shape to prevent the third harmonic from forming a circuit.