JPH0576156A - Device for detecting short-circuit across field winding layers - Google Patents

Abstract

PURPOSE:To provide a field winding layer short device wherein a detecting probe is surely mounted and fixed and its mounting position can be confirmed, with a rotor easily extractable and reinsertable, in a field winding layer short test for a generator under continuous operation. CONSTITUTION:A detecting probe 3 with a built-in pickup coil is set up adjacently to an external peripheral surface of a rotor 1 and further movably in a radial direction through ventilating ducts 4 of a stator core 2, in an air gap formed between the rotor 1 and the stator core 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to attachment of a probe for detecting a field winding interlayer short circuit provided in an air gap of a rotary electric machine.

[0002]

2. Description of the Related Art For example, in a turbine generator, there are a plurality of grooves axially provided on the outer peripheral surface of a rotor formed in the shape of a round rod, in which field windings are wound and embedded. An electromagnet is formed by energizing this.

Should an interlayer short circuit occur between the field winding conductors buried in the rotor groove, magnetic and thermal imbalance will occur in the rotor, resulting in large rotational vibrations and a large generator vibration. Driving may be impossible.

The inter-layer short circuit between the field winding conductors which causes such a problem occurs when the centrifugal force due to the high speed rotation of the rotor and the force due to the temperature rise during operation are acting. , Had to detect during rotation.

As this detection method, the difference between the local leakage magnetic flux on the outer peripheral surface of the rotor and the leakage magnetic flux generated by the field winding which does not cause the interlayer short circuit is detected to detect the field causing the interlayer short circuit with high sensitivity. A method of identifying a groove in which a magnetic winding conductor is embedded is known.

This method is disclosed in, for example, Japanese Unexamined Patent Publication No. 1-234035, in a cylindrical probe 3 provided close to the air gap on the outer peripheral surface of the rotor 1 as shown in FIGS. By embedding a pickup coil (not shown) and crossing the leakage flux 7 generated by the field winding 6 with the pickup coil, the irregularity of the voltage waveform is detected, and the field winding conductor in which the interlayer short circuit has occurred is embedded. It identifies the entrapped groove.

[0007]

However, in this detection device, the probe 3 needs to be fixed in close proximity to the rotor surface, and must be projected further toward the rotor surface side than the outer diameter surface of the retaining ring. It became an obstacle when pulling out or re-inserting the child 1 from the inside of the stator. Therefore, when the rotor is pulled out and reinserted, it is necessary to slide the tab wedge cross-sections of the probe wedge 14 containing the probe 3 and the stator wedge 15 in the axial direction of the air gap to remove them from the stator wedge 15. This work is in a fairly narrow place, and it was very difficult to fix the lead wires 12 and the like so that they would not be blown off by the wind.

In the present invention, the probe of the inter-layer short-circuit detecting device for the field winding is removed by removing the rotor by eliminating the conventional drawbacks as described above.
It is an object of the present invention to provide a device that can be moved in the radial direction without obstruction during re-insertion and facilitates maintenance and fixation.

[0009]

SUMMARY OF THE INVENTION The present invention is a device for detecting an interlayer short circuit occurring in a field winding embedded in a rotor groove of a rotary electric machine, which comprises a stator core of the rotary electric machine and a rotary core. A probe with a built-in pickup coil is provided in the air gap formed between the outer circumference of the stator and the outer circumferential surface of the rotor, and the probe is embedded in the stator core. Is supported and fixed to the inner spacing piece by a probe stopper, and a probe slide mechanism is provided at one end of the probe stopper to allow the probe to slide in the radial direction.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 and FIG. 2 are schematic diagrams showing the essential parts of an embodiment of a field winding interlayer short-circuit detecting device according to the present invention. FIG. 1 shows a probe 3 incorporating a pickup coil of the interlayer short-circuit detecting device. The state of being inserted into the stator core 2 and being incorporated in the air gap of the rotating electric machine is shown. FIG. 2 shows how the probe 3 is attached. Insert the probe 3 into a part of the cooling ventilation duct 4 provided in the axial direction of the stator core 2,
The positions in the axial direction and the circumferential direction are set, and the probe stopper 18 is inserted and fixed to the inner spacing piece 19. The probe 3 is fixed to the probe guide 17 attached to the stator frame so as to be movable in the radial direction on the outer diameter side of the iron core.

In the above structure, the probe 3 is attached to the inner spacing piece 19 which constitutes the cooling ventilation duct 4 provided in the axial direction in the fixed iron core, so that the fixation can be surely made firm, and , Probe 3 with probe guide 17
Is fixed so as to be movable in the radial direction, the probe 3
Is easy to set, and the rotor 1 can be pulled out and reinserted easily without disassembling the device. The main effects of this example are shown below.

1) Since the fixed position of the probe 3 is outside the stator core, the mounting state can be visually confirmed, and the gap between the rotor surface and the probe can be easily adjusted. Therefore, highly reliable detection is possible. It is possible.

2) In the probe 3, by adjusting the probe guide 17 and sliding it in the radial direction, the protrusion dimension from the inner peripheral surface of the stator core can be changed, so that the probe wedge 14 is inserted when the rotor is inserted or withdrawn. There is no need to disassemble, improving the reliability of probe mounting.

3) Since the inter-layer short circuit detection of the field winding can slide the probe 3 in the radial direction inside the probe guide 17 as shown in FIG. 2, after mounting the probe,
There is no need to disassemble the probe wedge when inserting or pulling out the rotor, so that recovery is facilitated, and it becomes possible to easily perform the inter-layer short circuit detection test of the field winding as well as the generator continuous operation.

[0016]

As described above, according to the present invention,
By installing the probe of the inter-layer short circuit detector for the field winding in the air duct so that it can move in the radial direction, the probe mounting part can be securely fixed with a simple structure and the mounting position can be confirmed, and the rotor can be pulled out. It is possible to provide an interlayer short-circuit detection device for field windings that can be easily reinserted.

In addition, the field winding inter-layer short circuit detection test during continuous operation of the generator can be solved by the problem that the probe cannot be fixed due to a defect in the probe mounting portion. It is possible to avoid the process of discharging and refilling the hydrogen gas in the machine, such as discharging and refilling, which may cause an explosion depending on the hydrogen gas concentration.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment in which a probe for detecting a field winding interlayer short circuit according to the present invention is mounted in a stator core.

FIG. 2 is a detailed view of the probe mounting portion of FIG.

FIG. 3 is an overall configuration diagram in which a conventional field winding interlayer short-circuit detection probe is mounted in an air gap of a rotating electric machine.

FIG. 4 is a detailed view of the probe mounting portion of FIG.

[Explanation of symbols]

1 ... Rotor 2 ... Stator core 3 ... Probe 4 ... Ventilation duct 5 ... Rotor groove 6 ... Field winding 7 ... Leakage magnetic flux 8 ... Armature winding 10 ... Stator frame outer peripheral plate 12 ... Lead wire 13 … Voltage indicator 14… Probe wedge 15… Stator wedge 16… Rotator wedge 17… Probe guide 18… Probe stopper 19… Inner spacing piece

Claims (1)

[Claims] 1. A device for detecting an interlayer short circuit occurring in a field winding embedded in a rotor groove of a rotating electric machine, wherein the device rotates in an air gap formed between the stator and the rotor. A field winding inter-layer short-circuit detection device, characterized in that a probe having a built-in pickup coil is attached to the outer peripheral surface of the stator so as to be movable in the radial direction via a stator core ventilation duct.