Electric arc detector and method for detection of undesired electric arcs pertaining thereto

FIELD: electricity.

SUBSTANCE: electric arc detector for detection of undesired electric arcs contains an antenna for receipt of the electromagnetic signal representing the electric arc and a discriminator for analysis of the signal from the antenna. The discriminator contains a spectrum analyser designed so that to enable detecting whether the signal represents a normal electric arc or an undesired electric arc. The discriminator is designed so that to enable detecting whether the signal represents a normal electric arc or an undesired electric arc by way of comparing the levels of signal at the signal spectrum frequencies corresponding to at least one partial reference spectrum and defining of an electric arc a normal one if the deviation from the reference spectrum is less than the threshold deviation. Additionally presented is a corresponding method.

EFFECT: establishment of difference between normal and undesired electric arcs.

13 cl, 3 dwg

 

The technical FIELD TO WHICH the INVENTION RELATES.

The present invention relates mainly to the detection of electric arcs, and more specifically to the establishment of differences between normal and undesirable electric arcs.

PRIOR art

The formation of an electric arc, i.e. the electric discharge can occur in many electric fields. Some arcing may be an ordinary part of the operation of the device, although some arcing is undesirable and may even be dangerous.

As a first example in power transformers, switches branches under load (POPN) used to change the connections of the branches of the transformer windings, while the transformer is energized. Occurs the formation of some of the electric arc, and it is desirable to keep such arcing inside the vacuum chamber, rather than to prevent arcing in the transformer oil. Arcing in the oil can lead to wear of the contacts and lower quality oil. It is therefore desirable to be able to establish the difference between normal arcing inside the vacuum chamber and unwanted coord is m arc outside the vacuum chamber. The exception to arcing in the oil allows the use of less expensive material contacts and increase the time between oil changes, thus allowing longer intervals between maintenance service.

As a second example, both normal and unwanted arcing can occur in electric motors, and it is desirable to set the difference between the two formations of the electric arc.

Therefore, there is a need to determine and establish the differences between the normal electric arcs and unwanted electric arcs.

SUMMARY of the INVENTION

The present invention is the provision of an electric arc detector and method of detecting and establishing the difference between the normal electric arcs and unwanted electric arcs.

According to the invention is proposed electric arc detector for detecting unwanted electric arcs. The electric arc detector includes an antenna for receiving the electromagnetic signal representing an electric arc, and a discriminator for analysis of the signal from the antenna, and the discriminator contains a spectrum analyzer configured to detect displays whether the signal nor the actual electric arc or unwanted electrical arc. The discriminator is arranged to detect, displays whether the signal is normal electric arc or unwanted electrical arc by comparing the signal levels in the frequency spectrum of the signal corresponding to at least one partial reference spectrum, and determining an electric arc as a normal arc if the deviation from the reference range is less than a threshold deviation.

The spectrum analyzer allows for the purpose of establishing differences between normal and undesirable electric arcs using only the signal from the antenna. Moreover, using the spectrum analyzer, the establishment of differences is independent of time, allowing detection of unwanted electric arc at any time. Through the use of threshold deviations usual small deviations from the ideal signal are interpreted correctly. The threshold value can be adjusted as required. Only by comparing the levels of signals at frequencies corresponding to one or more partial reference spectra, is more faithful and reliable determination, especially when the frequency range for partial support of the spectra is chosen where the difference between normal and undesirable electric arc is defined as Rel is relatively large.

The electric arc may relate to the operation of the electrical device. In other words, any electrical device, where there are normal and undesirable electric arc, will have the advantage of using the present invention, such as electrical machines such as transformers, motors, circuit breakers, etc.

The electric arc may relate to the operation of the switch branch under load of the power transformer, and a normal arc may be arc inside the vacuum chamber of the switch branch under load and unwanted arc may be an arc on the outside of the vacuum chamber. In switches of branches under load power transformers exist and normal electric arc, and the unwanted electric arc, therefore, the present invention provides a technical effect.

The electric arc detector may further comprise a band-pass filter, configured to receive an input signal from the antenna and provides an output signal to the discriminator.

The electric arc detector may further comprise a mixer, configured to receive an input signal from the bandpass filter, and the mixer is additionally connected to receive the input signal from the generator, and a lowpass filter configured to receive the input signal from the mixer and provides an output signal to the discriminator.

This makes it possible to carry out additional processing at low frequencies.

The electric arc detector may further comprise: an envelope detector, configured to receive the input signal from the low pass filter and provides an output signal to the discriminator.

The second aspect of the present invention is a method of detecting unwanted electric arcs. The method contains the steps that receive the electromagnetic signal representing an electric arc using the antenna and providing the signal to the discriminator, and establish the difference discriminator between normal electric arc and unwanted electric arc, using the signal from the antenna. The establishment phase of the differences provides the steps, which use the spectrum analyzer to differentiate between normal electric arc, and the unwanted electric arc and compare the signal levels in the frequency spectrum of the signal corresponding to the at least one partial reference spectrum, determine the electric arc as normal, if the deviation from the reference range is less than a threshold deviation.

At the stage of establishing differences can be mounted on the difference between the normal electric arc inside the vacuum chamber Perek is the breaker branches under load for the power transformer and the unwanted electric arc outside the vacuum chamber.

In the identify phase deviation can be determined using the calculation of standard values.

It should be noted that any sign of the first aspect may be applied to the second aspect, and Vice versa.

In General, all terms used in the claims, should be interpreted according to their ordinary meanings in the technical field, unless explicitly defined otherwise. All references to the element, device, component, means, step must be interpreted openly as referring, at least one unit element, device, component, means, step, etc. unless explicitly stated otherwise. The steps of any method disclosed in the materials of the present application should not be carried out in the exact open order, unless expressly stated otherwise.

BRIEF DESCRIPTION of DRAWINGS

The invention is further explained in the description of the preferred variants of the embodiment with reference to the accompanying drawings, in which:

figure 1 depicts a diagram of the switch 102 branches under load transformer;

figure 2 depicts the scheme of the detector 231 electric arc, which may, for example, be used to switch branches under the load of figure 1; and

figure 3 depicts a block diagram of the sequence of operations of a method of detecting unwanted ELEH the electrical arcs.

DESCRIPTION of the PREFERRED embodiments

The present invention now will be described more fully below with reference to the accompanying drawings showing specific embodiments of the invention. This invention may, however, be embodied in many different forms and should not be construed as limited options for implementation outlined in the materials of the present application; rather, these embodiments of provided as an example so that this disclosure will be full and complete and will fully convey the scope of the invention for specialists in this field of technology. The same reference numbers indicate identical elements throughout the description.

1 shows a diagram of the switch 102 branches under the load of the transformer. Switch branch under load (POPN) is used to change the connection of the branches of the windings of the transformer when the transformer is plugged in. First will be explained the components POPN 102 followed the script of their use. As shown in figure 1, there are several connections 107a-d branches to accommodate different voltages. Some of these compounds 107a-b branches located on one side and some of these compounds 107c-d branches located on the other side. is there two selector 115a-b branches on each side. The left selector 115a branches connected to the connection 107a branch and right selector 115b branches here connected with the connection 107c branches.

The clamp 103 is used to connect the load. The clamp is connected to two vacuum switches 111a and 111b. The left vacuum switch 111a is connected to the first switch a selector. The right vacuum switch 111b is connected with the resistor 105. It should be noted that the resistance 105 may be a simple resistor or reactor resistance. Resistance 105 is additionally connected to the second switch 109b of the selector. As you can see, both switches 109a-b selector can be connected either with the left selector 115a branches, or with the right selector 115b branches.

In the situation shown in figure 1, both of the selector switch are connected with the left selector 115a branches. Although both the vacuum switch 111a-b are closed, the clamp 103 is actually connected with the left selector 115a branches, which is connected to the connection 107a branches.

Now will be described an example of how the clamp 103 is supplied with the new voltage without interrupting the power supply. In other words, the load can be connected with clip 103 in the course of this procedure.

Originally selector 115b branches connected to the connection branch corresponding to wish is the new voltage. In this example, under the desired connection branch connection is a connection 107c branches. If required, the selector 115b branches, which currently is not under load, performs any necessary switches for connecting the desired connection branch (which is required).

Then the left vacuum switch 111a is opened, thereby the first switch 109a branches can be switched so that it will connect with the right switch 115b branches. The first switch 109a branches located outside the load during switching because the left vacuum switch 111a is open.

The left vacuum switch 111a is then closed, connecting the clamp 103 through the first switch 109a branches with the right switch 115b branches. Resistance 105 prevents a short circuit between connections 107a and 107c branches.

The right vacuum switch 111b is then opened, thereby the second switch 109b branches can be switched so that it will connect with the right selector 115b branches. The second selector 109b branches located outside the load during switching because the right vacuum switch 111b is open.

In conclusion, the right vacuum switch 111b is closed, thereby clamp 103 is connected with the right of selector is 115b branches and compound 107c branches. Because of the resistance of 105 almost the entire current will flow through the left vacuum switch 111a and the first switch 109a branches.

Thus, it is illustrated as clamp 103 is now connected with the new connection branches, while the transformer is in a condition that ensures its connection to the network. Although all of the opening and closing of the switches under load are carried out using vacuum switches 111a-b, an electric arc in oil should not occur in normal operation. The electric arc should occur in a vacuum switches 111a-b, but the switches are designed so that they are resistant to a large number of electric arcs.

This method works the same way for connections all connections 107a-b branch on the left side, with one difference is that the switches of the selector switch in the other direction.

It should be noted that the number of connections of the branches shown in figure 1, selected for illustrative purposes only; may be provided by any number of suitable compounds of branches.

Figure 2 shows a diagram of the detector 231 electric arc, which may, for example, be used with the switch 102 branches under load figure 1.

The detector 231 electric arc contains the antenna 232, which de is achteruit electromagnetic signal 230 from the electric arc. Electromagnetic signal 230 is, for example, by radiation that can be detected, even if the electric arc is formed inside the vacuum chamber and is forced to pass through the walls of the vacuum chamber and any surrounding oil. Also the signal radiation from the electric arc in the oil can be detected in this way. Therefore, the antenna 232 is not required to be in direct contact with the source of the electric arc. The signal from the antenna 232 passes through coaxial cable 234 to the bandpass filter 236. Band-pass filter increases the bandwidth at which the signal electric arc more significant. After amplification by the amplifier 238 signal is mixed in the mixer 240 signal generator 242 to reduce the frequency of the signal. The low pass filter 244 further reduces the bandwidth. After another gain amplifier detector 246 249 optional envelope generates the envelope signal provided from the amplifier 246. In conclusion, the discriminator 248 sets the difference between the normal electric arc inside or unwanted electric arc in any place outside the vacuum chamber 111a-b (figure 1).

The discriminator 248 contains the spectrum analyzer to establish the differences between electric arcs inside the vacuum chamber and electric arcs outside the vacuum chamber. When OUTSTA electric arc may, for example, to be established by the detection signal of at least a particular amplitude and/or signal, at least a specific duration.

The discriminator 248 works by comparing the spectrum of the signal received from the antenna, with the reference spectrum. The discriminator determines an electric arc as the arc is located inside the vacuum chamber, if the deviation from the reference range is less than a threshold deviation. Alternatively, it may be detected unwanted electrical arc, if the reference spectrum displays unwanted electric arc. In other words, the signal must not be the same as the reference signal to determine a match. The deviation can be detected, for example, using the standard deviation, but can be used any other suitable mechanism for determining the deviation. The reference range may consist of one or more medspectrum or partial reference spectra selected at frequencies, where it was found that the difference between normal and undesirable electric arc is large enough. Each of these partial reference spectra has the lowest and highest frequency, forming a strip, and the reference signal level (or equivalent) between the lowest and highest frequency.

Reference spectronics in memory 250, such as random access memory (RAM, RAM), a persistent storage device (RAM, ROM), flash memory, magnetic memory, optical memory or any combination of these memory types. Comparison discriminator 248 is carried out using a controller, which may be any available for commercial purchase by the Central processing unit (CPU, CPU), a digital signal processor (DSP, DSP) or any other electronic programmable logic device.

Not necessarily the discriminator may optionally include one or more of the previous components 236, 238, 240, 242, 244, 246, 249 for a simpler implementation.

The reference spectrum stored in the memory 250 may be a spectrum showing an electric arc inside the vacuum chamber, thus, the match will indicate that this signal shows an electric arc inside the vacuum chamber. Alternative or additionally, the reference spectrum stored in the memory 250 may be a spectrum showing the electric arc on the outside of the vacuum chamber, thereby match will indicate that the signal shows an electric arc outside the vacuum chamber.

Optional instead of the previously stored reference spectrum for the previous several spectra are stored in the memory 250 as an adaptive reference spectrum. To the Yes analysis of the new signal electric arc, it can be compared, as described above, with the reference range, but then the reference range is calculated as the average of the last saved spectra, i.e. as an adaptive reference range. The average is calculated for each frequency or frequency band of the spectrum. Unwanted electrical arc will then be different and deviate from the adaptive reference spectrum. If there are several unwanted electric arcs with similar range, it will eventually shift adaptive spectrum with a degree that new unwanted electric arc will be so close to the adaptive reference spectrum that they will not be considered as spam. Here, however, assuming that the number of spectra for normal electric arcs is large enough, a few unwanted electric arcs have already been detected, thus, may be generated by an emergency or panic situation.

Using adaptive reference spectra provides dynamic adaptive adjustment, if there are long-term trends, when the range of normal electric arc changes with time.

May not necessarily be considered the amount of electric arcs in the series of electric arcs. A series of electric arcs is the number of arcs associated with one complete switching from odnorazovaya branch to another. If the number deviates from the preset value, it may indicate the presence of an unwanted electric arc.

Using the spectrum analyzer, the discriminator can thus make a distinction between the normal electric arc inside the vacuum chamber of the switch branch under load and unwanted electric arc outside the vacuum chamber. The output signal of this analysis is provided on the clamp 252.

In addition to the implementation of the detection and to differentiate between normal and undesirable electric arcs switch branches under load, as described above, embodiments of the invention can be used for other applications. For example, embodiments of the invention can be used to detect and to differentiate between normal and unwanted arcing electric motors, circuit breakers or other electrical devices with normal and unwanted arcing.

Figure 3 depicts a block diagram of the sequence of operations illustrating a method of detecting electrical arcs switch branches under load.

At the initial stage 360 receiving the electromagnetic signal, the electromagnetic signal representing elektrichesky arc take from the antenna.

At step 362 compare the spectrum with the reference spectrum of the signal electric arc is compared with the reference spectrum. The reference spectrum may be continuous spectrum, or it can be one or more medspectrum, where each pospects is part of the signal frequency. For example, there may be one or more specific characteristics frequency plots, which are analyzed, while other frequencies are ignored and are not compared. This allows more accurate and reliable determination of the differences between normal and undesirable electric arc. The reference spectra are chosen to be the frequency at which the difference between the normal and the unwanted electric arc is relatively large. The comparison between the received signal and the reference spectrum may, for example, be carried out using the calculation of standard values.

At step 364 conditions between normal or unwanted electric arc determines displays whether the signal representing the electric arc, normal, permissible electric arc, or it displays unwanted electric arc.

If the reference range in the previous step 362 displays the normal electric arc, the deviation is smaller than a threshold deviation from it, indicates that the signal which displays a normal electric arc. Otherwise, the signal is determined as an indication of undesirable electric arc.

Conversely, if the reference range in the previous step 362 displays unwanted electric arc, the deviation is smaller than a threshold deviation from it, indicates that the signal displays unwanted electric arc. Otherwise, the signal is determined as an indication of undesirable electric arc.

If the signal is determined as the normal signal of the electric arc, the process continues to step 366 normal electric arc. Otherwise, the process continues to step 368 unwanted electric arc.

At step 366 normal electric arc can be generated signal indicating that detektirovaniya electric arc is a normal arc. Optional for normal electric arc is not generated no signal.

At step 368 unwanted electric arc can be generated signal indicating that detektirovaniya electric arc is undesirable electric arc. Other devices can respond to this signal, for example, providing a warning to the operator, or in an emergency situation, disconnecting electrical power from the machine that produces unwanted electric arc.

The invention is a General manner described above with reference to some embodiments of. However, as is easily understandable to a person skilled in the art other embodiments of, other than those which have been disclosed above are equally possible within the scope of the invention as defined by the attached claims.

1. The electric arc detector for detecting unwanted electric arcs, comprising:
antenna (232) for receiving the electromagnetic signal (230), shows an electric arc; and
the discriminator (248) to analyze the signal from the antenna (232)containing the spectrum analyzer is arranged to detect, displays whether the signal is normal electric arc or unwanted electric arc,
characterized in that
the discriminator is arranged to detect, displays whether the signal is normal electric arc or unwanted electric arc, by comparing the signal levels in the frequency spectrum of the signal corresponding to the at least one partial reference spectrum, and determining an electric arc as a normal arc if the deviation from the reference range is less than a threshold deviation.

2. The electric arc detector according to claim 1, in which the electric arc refers to the operation of the electrical device.

3. The electric arc detector according to claim 1 or 2, in which electronic the historical arc refers to the switch (102) branches under load of the power transformer, normal electric arc is an electrical arc inside the vacuum chamber (111) unit switch (102) branches under load and the unwanted electric arc is an electrical arc on the outside of the vacuum chamber (111).

4. The electric arc detector according to claim 1 or 2, in which the reference range is adaptive reference spectrum, calculated as the average of the predetermined number of many recently analyzed the spectra of the signal.

5. The electric arc detector according to claim 1 or 2, additionally containing a bandpass filter (236), configured to receive an input signal from the antenna (232) and provides an output signal to the discriminator (248).

6. The electric arc detector according to claim 3, in which the reference range is adaptive reference spectrum, calculated as the average of the predetermined number of many recently analyzed the spectra of the signal.

7. The electric arc detector according to claim 3, additionally containing a bandpass filter (236), configured to receive an input signal from the antenna (232) and provides an output signal to the discriminator (248).

8. The electric arc detector according to claim 5, further comprising:
mixer (240), configured to receive the input signal from the band pass filter (236), and mixer (240) d is further connected to receive the input signal from the generator (242), and
the low pass filter (244), configured to receive an input signal from the mixer (240) and provides an output signal to the discriminator (248).

9. The electric arc detector according to claim 7, further comprising:
mixer (240), configured to receive the input signal from the band pass filter (236), and mixer (240) is additionally connected to receive the input signal from the generator (242), and
the low pass filter (244), configured to receive an input signal from the mixer (240) and provides an output signal to the discriminator (248).

10. The electric arc detector of claim 8 or 9, further comprising:
detector (249) envelope made with the possibility of receiving the input signal from the low pass filter and provides an output signal to the discriminator (248).

11. Method of detecting unwanted arcs containing phases in which:
take electromagnetic signal (230), shows an electric arc using the antenna (232), and provide the signal to the discriminator (248); and
set in the discriminator (248) the difference between the normal electric arc and unwanted electric arc, using the signal from the antenna (232) and using the spectrum analyzer to establish the differences between a normal arc and unwanted electric arc,
different is the present, what
the establishment phase of the differences provides the steps, which compare the signal levels in the frequency spectrum of the signal corresponding to the at least one partial reference spectrum, and determine the electric arc as a normal arc if the deviation from the reference range is less than a threshold deviation.

12. The method according to claim 11, in which at the stage of establishing differences establish the difference between the normal electric arc inside the vacuum chamber of the switch branch under load for the power transformer and the unwanted electric arc outside the vacuum chamber.

13. The method according to claim 11 or 12, in which the step of determining the deviation is determined using the calculation of standard values.



 

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EFFECT: increase in reliability of device switching on and decrease of its weight and dimensions.

2 dwg

FIELD: electrotechnical equipment.

SUBSTANCE: innovation is designated for the application to schemes for measuring parameters and the control of quality of the electrotechnical equipment and presupposes application of a noncontrollable gas-discharge arrestor as a protecting device for DC circuit installments having inductivity due to inductive current arising during the DC circuit break as a result of self inductance; after the arrestor discharge caused by the discharge voltage, the burning of the normal glow discharge is supported by the diminishing (due to the putout of the energy accumulated in the inductance) inductive current until the current is able to support the glow discharge; the glow gas discharge transforms into the dark discharge; the amperage and the voltage are diminishing to nil in proportion of the energy putout accumulated in the inductance.

EFFECT: enhancement of the efficiency of the equipment protection from the inductive current irrespective the polarity of the operation voltage and electromotance.

1 cl, 5 dwg

FIELD: electricity.

SUBSTANCE: according to method of arcless switching, prior to current switching at section of circuit, comprising parallel-connected circuit breaker and load, current pulse is sent through circuit breaker, and its value is equal to, and direction is opposite to accordingly value - I0 and direction of switched current. Synchronously with current pause, at switched section of circuit, circuit breaker electrodes are opened at the specified distance relative to each other, at the same time current pulse is sent through circuit breaker by connection of artificial long line (ALL) in parallel, which is previously charged to voltage of U0=I0·ρ, where ρ=(10-1·10-3)Rl - wave resistance of ALL, and Rl - load resistance. Then prior to or at the moment of current pause termination, circuit is broken between the second and third or third and fourth links of artificial long line, as current in inductance accordingly reaches the third or fourth link of zero value.

EFFECT: reduced weight and dimensional parametres of artificial long line used to create current pause at switching section of circuit by possibility to use only two or three capacitors in ALL with working voltage equal to product of switched current and load resistance.

4 dwg

FIELD: electricity.

SUBSTANCE: arc-quenching system includes contacts and insulation case in the form of hollow tube with slots on internal surface positioned over gaps along the whole case length. Each slot features through orifices opposite to each other. System features longitudinal magnetic blowout device.

EFFECT: enhanced heat transfer from electric arc to environment, increased arc-quenching ability due to arc rotation between case slots and reduced exhaust gas effect on internal case surface.

2 dwg

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