RU2490653C2 - Conductor insulation failure detection - Google Patents

Abstract

FIELD: instrument making.

SUBSTANCE: electromagnetic field resonance oscillations are excited in oscillatory circuit comprising inductance and capacitor which is galvanically isolated from measuring circuit. Note here that capacitor and insulated conductor are place in fluid to displace said conductor relative to capacitor. Note also that insulated conductor insulation failure is detected by variation in electromagnetic field oscillatory circuit resonance oscillation frequency.

EFFECT: higher sensitivity.

2 cl, 1 dwg

Description

Technical field

The invention relates to measuring technique and can be used to determine wire insulation defects, for example, air gaps inside the wire insulation (or between the insulation and the wire when they are not snug) or the lack of insulation in certain places on the surface of the wire.

State of the art

The closest analogue - the prototype of the proposed method for determining defects in insulation of wires is a method of measuring the electrical characteristics of the medium (see the description in the application for the invention of the Russian Federation No. 99105386, IPC G01N 27/00, published on January 20, 2001).

In this method, a sample of the test medium is placed inside a capacitive sensor included in the oscillatory circuit, in which resonant oscillations of the electromagnetic field are excited, the test medium is electrically applied to the test medium, the molecules of the test medium are polarized, and their own electric field of the test medium interacts with the electric field capacitive sensor.

As a result of this, the capacitance of the capacitive sensor is changed and the period of resonant oscillations of the electromagnetic field of the oscillatory circuit is determined. In this case, the change in the period of resonant oscillations of the electromagnetic field of the oscillatory circuit is a measure of the change in the dielectric constant of the test medium.

In this method of measuring the electrical characteristics of the media, the dielectric constant of the test media is determined.

In the proposed method, defects in insulation of wires are determined.

Disclosure of invention

The objective of the invention is to expand the arsenal of technical means for determining defects in insulation of wires (insulated wires) and increase sensitivity.

The problem is solved using the characteristics specified in the 1st paragraph of the claims common with the prototype, such as in an oscillatory circuit that contains an inductor and capacitor, and is galvanically isolated from the measuring circuit, resonant oscillations of the electromagnetic field are excited, and distinctive essential features such as a capacitor and an insulated wire are placed in a liquid medium, the insulated wire is moved relative to the capacitor, and insulation defects of the insulated wire are detected lyayut by changing the resonant frequency of the electromagnetic field oscillations of the oscillatory circuit.

In paragraph 2 of the formula is reflected in the form of a liquid medium, namely, the liquid medium is preferably distilled water or ethyl alcohol.

The placement of the capacitor and insulated wire in a liquid medium increases the sensitivity of the device that implements the technical implementation of the proposed method. In this case, a liquid medium with a higher dielectric constant tends to "unload" and "shift" part of the electric voltage to the insulation of the wire with a lower dielectric constant (see the book, edited by Yu.V. Koritsky. Handbook of electrical materials: 3 vol. T. 1 - M .: Energoatomizdat, 1986, p. 24).

The above set of essential features allows you to get the following technical result - the expansion of the arsenal of technical means for determining defects in wire insulation and increasing sensitivity.

Brief Description of the Drawing

The drawing shows a structural diagram of a device that implements the technical implementation of the proposed method for determining defects in insulation of wires.

The implementation of the invention

A device that implements the technical implementation of the proposed method for determining wire insulation defects contains an oscillating circuit 1 (see. Fig.) And a measuring circuit 4.

The oscillation circuit 1 contains a capacitor 3 and an inductor 2 of the oscillatory circuit 1. The plates of the capacitor 3 are made in the form of two metal rings and are connected to the first and second terminals of the inductor 2 of the oscillatory circuit 1. At the same time, the plates of the capacitor 3 cover the insulated wire 5.

The insulated wire 5 and the capacitor 3 are placed in a liquid medium 6 (indicated by a dashed line in the drawing), which is distilled water or ethyl alcohol.

The measuring circuit 4 contains an inductor 7 for pumping energy into the oscillatory circuit 1, an inductor 8 for reading the frequency of the resonant oscillations of the oscillatory circuit 1, an OR element 9, a transistor 10, a comparator 11, and a computing device (not shown in the figure).

The second 12 input of the OR element 9 is the start input of continuous undamped resonant vibrations of the electromagnetic field of the oscillatory circuit 1. The output of the OR element 9 is connected to the base of the transistor 10, the emitter of which is connected to the "General" power output.

The first and second conclusions of the inductor 7 of pumping energy into the oscillating circuit 1 are connected respectively to the collector of the transistor 10 and the positive terminal 13 of the DC power source (not shown) of the measuring circuit 4.

The first and second conclusions of the inductance coil 8 of reading the frequency of the resonant vibrations of the oscillatory circuit 1 are connected respectively to the output "General" power and direct input of the comparator 11, to the inverse input of which a reference voltage is supplied. The output of the comparator 11 is connected to the first input of the OR element 9 and the computing device.

The inductor 2 of the oscillatory circuit 1, the inductor 7 of pumping energy into the oscillatory circuit 1 and the inductor 8 of reading the frequency of the resonant oscillations of the oscillatory circuit 1 can be performed by winding the wire on the dielectric frame.

In the drawing, the arrow shows the direction of movement of the insulated wire 5 relative to the capacitor 3.

A device that implements the technical implementation of the proposed method for determining defects in insulation of wires, works as follows.

After turning on the power from the parallel channel of the computing device to the second 12 input element OR 9 serves a single positive impulse. As a result, a positive pulse arrives at the base of the transistor 10, which opens the transistor 10, and a current begins to flow through the induction coil 7 of the energy pumping into the oscillation circuit 1, which induces the EMF - the electromotive force of induction in the oscillatory circuit 1, in which resonant oscillations of the electromagnetic field occur.

The frequency of the resonant oscillations of the electromagnetic field of the oscillatory circuit 1 is measured by taking the frequency from the inductor 8 of reading the frequency of the resonant oscillations of the oscillatory circuit 1, which then goes to the direct input of the comparator 11, to the inverse input of which the reference voltage is supplied. From the output of the comparator 11, the positive rectangular signals arrive at the first input of the OR element 9 (at the second 12 input of the OR element 9, a logic zero level is supplied at this time) and to the computing device.

From the output of the OR element 9, rectangular pulses arrive at the base of the transistor 10, upon opening of which a current flows through the inductor 7 of the pumping energy into the oscillation circuit 1, and when it changes, an induction emf arises in the oscillatory circuit 1. Under the influence of EMF induction in the oscillatory circuit 1, currents occur, consistent with the direction of the current in the oscillatory circuit 1 in each half-cycle of the oscillations of the oscillatory circuit 1.

In the positive half-cycle of oscillations in the oscillation circuit 1, energy is pumped during an increase in the current in the inductor 7 of pumping energy into the oscillation circuit 1. In the negative half-cycle, the energy is pumped during the decrease in the current in the inductor 7 of energy pumping in the oscillator circuit 1, since energy transfer occurs at moments of change in current in the inductor 7 of pumping energy into the oscillation circuit 1.

Thus, in the oscillating circuit 1, continuous undamped resonant oscillations of the electromagnetic field are excited with energy pumping at certain points in time, the amplitude of the oscillations is increased at these moments, and these oscillations are converted into positive rectangular signals.

The insulated wire 5 is moved relative to the capacitor 3, and the violation of the insulation integrity of the insulated wire 5 is determined by changing the frequency of the resonant vibrations of the electromagnetic field of the oscillating circuit 1.

Industrial applicability

A device that implements the proposed method for determining wire insulation defects can be made of available elements and materials in the conditions of radio production. The proposed method for determining wire insulation defects will find wide application in the application devices of the present invention, other private automation of flow measurement will be obvious to specialists.

This description and examples are considered as material illustrating the invention, the essence of which and the scope of patent claims are defined in the following claims, a combination of essential features and their equivalents.

The proposed method can be used to determine the air gaps inside the insulation of the wire (or between the insulation and the wire when they are loose) or the lack of insulation in separate places on the surface of the wire.

Claims (2)

1. The method of determining insulation defects of wires, which consists in the fact that in an oscillating circuit that contains an inductor and a capacitor and is galvanically isolated from the measuring circuit, resonant vibrations of the electromagnetic field are excited, characterized in that the capacitor and insulated wire are placed in a liquid medium, move the insulated wire relative to the capacitor, and the violation of the integrity of the insulation of the insulated wire is determined by changing the frequency of the resonant oscillations by the electric agnitic field of the oscillatory circuit. 2. The method according to claim 1, characterized in that the liquid medium is preferably distilled water or ethyl alcohol.