JPH0373222B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a method of supplying power supply voltage to a stator of a rotating electric machine, and particularly relates to a method for supplying power supply voltage to a stator of a rotating electrical machine, and particularly to a method for supplying power voltage to a stator of a three-phase stator winding having a winding start and a winding end for each phase. The present invention relates to a method of supplying power voltage to a stator of a rotating electric machine, in which primary lead wires are provided at the beginning of each winding, and neutral lead wires are provided at each end of the winding.

[Background of the Invention] A rotating electrical machine in which a three-phase stator winding having a winding start and a winding end for each phase is provided with a primary lead wire at each winding start and a neutral lead wire at each winding end. For example, in the stator of a three-phase motor, the power supply voltage is supplied to the primary lead wire, and the neutral lead wires are short-circuited with a shorting bar. This neutral lead wire is installed according to the customer's requirements, and is used to test the insulation of the stator winding of each phase and install the current transformer to protect the stator. Electric motors are on the rise.

By the way, in the stator of a motor that is used by supplying the power supply voltage from the primary lead wire in this way, the rated voltage, which is the power supply voltage, is directly applied to the stator winding at the beginning of the winding to which the primary lead wire is connected. Therefore, the insulation deteriorates quickly, and since the voltage applied to the stator winding at the end of the winding to which the neutral lead wire is connected is almost zero, the insulation hardly deteriorates. In other words, the insulation of the stator winding at the beginning of the winding deteriorates faster than that of the stator winding at the end of the winding, and for this reason, even if the stator winding at the end of the winding still has sufficient insulation life, the stator winding at the beginning of the winding does not. Since the insulation life of the stator is determined by the insulation life of the wires, the insulation life of the conventional stator has been relatively short.

[Object of the invention] The present invention has been made in view of the above points,
The object of the present invention is to provide a method for supplying power voltage to a stator of a rotating electric machine, which makes it possible to double the insulation life.

[Summary of the invention]

That is, the present invention applies to a rotating electrical machine in which a three-phase stator winding having a winding start and a winding end for each phase is provided with a primary lead wire at each winding start and a neutral lead wire at each winding end. In the method of supplying power voltage to the stator, the neutral lead wires of each phase are shorted together using a shorting bar to supply power voltage to the primary lead wires of each phase, and the primary lead wires of each phase are connected to each other. When the stator winding at the beginning of each phase reaches its insulation life,
Remove the shorting bar that shorted the neutral lead wires of each phase, short the primary lead wires of each phase to switch to the neutral lead wire of each phase, and remove the shorting bar to switch to the neutral lead wire of each phase. The main feature is that the power supply voltage is supplied to the wire, and as a result, the stator winding on the neutral lead wire side has a period of insulation deterioration that is approximately equal to that of the stator winding on the primary lead wire side. After the same period of time, the insulation deteriorates and reaches the end of its lifespan.

[Embodiments of the invention]

The present invention will be explained below based on the illustrated embodiments. An embodiment of the present invention is shown in FIGS. 1-4. Winding start 1a, 2a, 3 for each phase
a, and winding starts 1a, 2a, 3 of three-phase stator windings 1, 2, 3 having winding ends 1b, 2b, 3b.
The primary lead wires 4, 5, and 6 are connected to a, respectively, at the end of the winding 1.
b, 2b, 3b have neutral lead wires 7, 8, 9, respectively.
In the stator of a three-phase motor provided with
In this embodiment, the neutral lead wires 7, 8, and 9 are short-circuited with a shorting bar 10 to supply power voltage to the primary lead wires 4, 5, and 6 (see Fig. 1). , 6 are short-circuited with a short-circuiting bar 10 to supply power supply voltage to neutral lead wires 7, 8, and 9 (second
(see figure). By doing this, the stator insulation life is determined by approximately twice the period in which the stator windings 1, 2, and 3 at the beginning of winding 1a, 2a, and 3a reach their insulation life. , which made it possible to double the insulation life 3
The stator of the phase motor can be obtained.

That is, the neutral lead wires 7, 8, and 9 are short-circuited with the shorting bar 10 as shown by the solid line in the figure (see Figure 4),
It is used by supplying power supply voltage to the primary lead wires 4, 5, and 6. When used in this way, the winding starts 1a, 2 connected to the primary lead wires 4, 5, 6, respectively.
Since the rated voltage, which is the power supply voltage, is applied to the stator windings 1, 2, and 3 of a and 3a, the insulation deteriorates.
When these reach the end of their insulation life, they can be used by supplying power supply voltage from the neutral lead wires 7, 8, and 9. In other words, the primary lead wires 4, 5, and 6 are connected to the short-circuit bar 1 as shown by the two-dot chain line in the figure.
0 (see Figure 4), and the neutral lead wires 7, 8,
It is used by switching the power supply voltage to 9. In this way, the stator windings 1, 2, 3 at the winding ends 1b, 2b, 3b connected to the neutral lead wires 7, 8, 9, respectively, are replaced by the stator windings 1a, 2a, 3a at the winding beginnings. Since insulation has hardly deteriorated until windings 1, 2, and 3 deteriorate, insulation deteriorates after approximately the same period as stator windings 1, 2, and 3 at the beginning of winding 1a, 2a, and 3a. and reaches the end of its insulation life. In other words, the stator reaches its insulation life in almost twice the period of time that the stator windings 1, 2, and 3 on the winding start 1a, 2a, and 3a sides reach their insulation life, and the stator's life is longer than before. Insulation life can be doubled.

In FIG. 3, 11 is a terminal box.

〔Effect of the invention〕

As described above, the present invention has improved the stator insulation life compared to the past because the stator insulation life is determined by approximately twice the period in which the stator winding on the winding start side reaches its insulation life. It is now possible to double the lifespan, and it is possible to obtain a method for supplying power voltage to the stator of a rotating electrical machine that allows doubling the insulation life.

[Brief explanation of drawings]

FIG. 1 is a connection system diagram of stator windings when power voltage is supplied from the primary lead wire according to an embodiment of the method of supplying power voltage to the stator of a rotating electric machine according to the present invention, and FIG. A connection system diagram of the stator winding in the case of supplying the power supply voltage from the neutral lead wire according to an example, and FIG. 3 is a layout diagram showing the arrangement of the primary lead wire and the neutral lead wire in the terminal box according to the same example. , FIG. 4 is an explanatory diagram illustrating switching between the primary lead wire and the neutral lead wire in the terminal box according to the same embodiment. 1...Stator winding, 1a...Start of winding, 1b...
End of winding, 2... Stator winding, 2a... Start of winding, 2
b... End of winding, 3... Stator winding, 3a... Start of winding, 3b... End of winding, 4, 5, 6... Primary lead wire, 7, 8, 9... Neutral lead wire, 10 ...Short bar, 11...Terminal box.

Claims (1)

[Claims] 1. Fixing of a rotating electrical machine, in which a three-phase stator winding has a winding start and a winding end for each phase, and a primary lead wire is provided at each of the winding beginnings, and a neutral lead wire is provided at each of the winding ends. In the method for supplying power supply voltage to a power supply voltage, the neutral lead wires of each phase are short-circuited using a shorting bar to supply power supply voltage to the primary lead wires of each phase, and the primary lead wires of each phase are connected to each other. When the stator winding at the beginning of each phase reaches its insulation life, remove the shorting bar that shorted the neutral lead wires of each phase and short-circuit the primary lead wires of each phase. A method for supplying power supply voltage to a stator of a rotating electric machine, characterized in that the power supply voltage is supplied to the neutral lead wire of each phase from which the shorting bar is removed by switching to the neutral lead wire of each phase.