JPH06141461A - Detecting device for grounding of rotor winding of rotating electric machine - Google Patents

Abstract

PURPOSE:To provide a grounding detecting device which can detect the ground current of a rotor winding in a noncontact manner with easy maintenance in a rotating electric machine such as a generator or the like provided with an exciter. CONSTITUTION:A power supply 14 and a shape memorizing alloy 15 are connected to a rotor winding 4, and they are connected to a rotor shaft 2. On the other hand, an optical sensor head 16 which detects the deformation of the shape memorizing alloy 15 attached to the side face of a bracket, an optical signal from the optical sensor head 16 is input to a photoelectric converter 18 by an optical fiber, the optical signal is converted into an electric signal, the electric signal is input to a judgment circuit 17, and an alarm 20 is actuated by an output from the judgment circuit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for detecting grounding of a rotor winding of a rotary electric machine such as a generator using a brushless exciter.

[0002]

2. Description of the Related Art As shown in FIG. 5, a conventional rotor winding grounding detecting device (hereinafter simply referred to as a grounding detecting device) includes a field grounding detecting electric brush 1 and a rotor 2 of a rotating electric machine. (For example, the rotor shaft having a smooth surface) is contacted, and the ground current from the electric brush 1 operates the field ground detection relay 3 to detect the grounding of the rotor winding 4. In the figure, 5 is an exciter and 6 is a rectifier.

[0003]

In this ground contact detecting device, the electric brush on the stationary side of the rotating electric machine is in contact with the rotor and is sliding, so that even if the sliding location is, for example, a smooth rotating shaft. Electric brush wears. Therefore, maintenance is required to replace the electric brush when the rotating electric machine is continuously operated for a long time.

The object of the present invention is to solve the above-mentioned problems.
An object is to provide a ground detection device that requires no maintenance.

[0005]

According to the present invention, a rotor winding is electrically connected to a rotor shaft through a shape memory alloy and a power source, and the shape of the shape memory alloy is provided on the stationary side of a rotating electric machine. It is detected by the photodetector circuit. This optical detection circuit connects an optical fiber to an optical sensor head consisting of a light emitting part and a light receiving part, converts this optical signal into an electric signal by a photoelectric converter and inputs it to a judgment circuit, and outputs an alarm from this judgment circuit. To operate the vessel.

[0006]

In the present invention, the shape memory alloy is deformed when a ground current flows, and this is detected by the optical sensor, so that there is no sliding portion and maintenance such as replacement of parts due to wear is not required.

[0007]

1 is a partial side sectional view of a generator equipped with a rotor winding grounding detection device according to an embodiment of the present invention.
Is a rotor core, around which a rotor winding 4 is wound.
Reference numeral 12 is a stator frame, and 13 is a bracket. Rotor shaft 2
Is equipped with a brushless exciter (rotating side) 5 and a rectifier 6, which supply an exciting current to the rotor winding 4. In such a generator, the rotation side of the ground detection device connects the rotor winding 4 to the rotor shaft 2 via the power supply 14 and the shape memory alloy 15. Optical sensor head 1 on the stationary side
6 is fixed to the bracket 13, and the optical sensor head 16
The optical fiber 17 is drawn out from the optical fiber 17, and a photoelectric converter 18 is connected to the tip of the optical fiber 17 to convert an optical signal into an electric signal, the electric signal is input to the determination circuit 19, and the alarm device 20 is activated by the output.

FIG. 2 is a connection diagram on the rotating side of the ground detecting device.
Those denoted by the same reference numerals as those in FIG. 5 are the same parts. The shape memory alloy 15 used here has a function of generating Joule heat due to its electric resistance value when an electric current flows, and deforming at a certain temperature of this heat. FIG. 3 is a connection diagram of the stationary side of the ground detection device, which includes a light projecting unit 16A and a light receiving unit 16B.
The optical sensor head 16 composed of is provided on the side surface of the bracket 13 and is fixed at a position facing the shape memory alloy 15. An optical fiber 17 is connected to the optical sensor head 16, and an optical signal from the light receiving section 16B is incident on a photoelectric converter 18. The optical signal is converted by the photoelectric converter 18 into an electric signal, and a determination circuit 19 is provided. To enter. The output of the determination circuit 19 causes the alarm device 20 to sound. The alarm device 20 may be a display device (illumination display), or both may be used together.

FIG. 4 shows a detailed configuration of the decision circuit 19 in FIG. 3, in which the electric signal from the photoelectric converter 18 is applied to the reference voltage V _{S in the} comparator section 22 having the same reference voltage source 21.
Compared to. The output of the comparator unit 22 is input to the OR gate 23, the output of the OR gate 23 is ANDed with the clock pulse of the pulse oscillator 25 in the AND gate 24, and this output is input to the counter 26. The count value of the counter 26 is compared and input by the digital comparator 27, and the comparison reference value is given from the setter 28.
The comparator 27, which compares the magnitudes of both, obtains an output when the count value of the counter 26 exceeds a reference numerical value, and this output is input to the storage circuit 29. On the other hand, the output of the OR gate 23 is input to the differentiating circuit 30, and the output of the differentiating circuit 30 is input to the delay circuit 31. This output is input to the storage circuit 29 and output.

[0010]

In the ground detection device according to the present invention, the photodetector circuit is installed on the stationary side of the rotating electric machine, and the shape memory alloy provided on the rotor shaft is protected by the ground current from the rotor winding by the photodetector circuit. Since the deformation is detected, there are no sliding points and no parts need to be replaced, making maintenance extremely easy.

[Brief description of drawings]

FIG. 1 is a partial side sectional view of a generator equipped with a ground detection device according to an embodiment of the present invention.

FIG. 2 is a connection diagram on the rotation side of the ground detection device in FIG.

FIG. 3 is a connection diagram of the stationary side of the ground detection device in FIG.

FIG. 4 is a configuration diagram of a determination circuit in FIG.

FIG. 5 is a connection diagram of a conventional ground detection device.

[Explanation of symbols]

 2 rotor shaft 4 rotor winding 13 power supply 15 shape memory alloy 16 optical sensor head 16A light projecting section 16B light receiving section 17 optical fiber 18 photoelectric converter 19 determination circuit 20 alarm device

Claims (2)

[Claims] 1. A rotor winding is electrically connected to a rotor shaft through a shape memory alloy and a power source, and the shape of the shape memory alloy is detected by a photodetection circuit provided on the stationary side of a rotating electric machine. A rotor winding ground detection device for a rotating electric machine, comprising: 2. The determination circuit according to claim 1, wherein the optical detection circuit has an optical fiber connected to an optical sensor head including a light projecting portion and a light receiving portion, and the optical signal is converted into an electric signal by a photoelectric converter. A detector for grounding a rotor winding of a rotating electric machine, characterized in that an alarm device is activated by the output from this determination circuit.