RU89245U1 - PORTABLE DEVICE FOR REMOTE DETERMINATION OF THE DAMAGE PLACE OF AIR LINE INSULATORS (OPTIONS) - Google Patents

Abstract

1. A portable device for remote location of damage to defective insulators of overhead lines, consisting of a unit for generating probing voltage signals, including a storage capacitor and a switch, as well as a measuring part with a voltage divider, characterized in that the storage capacitor of the unit for generating probing voltage signals is made of high voltage and the switch is made in the form of a switching arrester, the measuring part additionally includes a microprocessor, the input of which connected to the voltage divider, and the output is connected in series with the information display unit, the voltage divider is connected in parallel with the high-voltage storage capacitor, the probing voltage signal generating unit further comprises a high-voltage charger, the output of which is connected to the input of the high-voltage storage capacitor and the input of the switching spark gap, and consists of high-frequency voltage converter, the output of which is connected in series with the input of the high-voltage rectifier unit with voltage multiplication, and the output of the high-voltage rectifier unit with voltage multiplication is connected in series with the input of the protective inductor. ! 2. A portable device for remote location of damage to defective insulators of overhead lines, consisting of a unit for generating probing voltage signals, including a storage capacitor and a switch, as well as a measuring part, characterized in that the storage capacitor of the unit for generating probing voltage signals in

Description

The utility model relates to energy, mainly to electric devices, and can be used to remotely identify the zone where defective insulators of overhead power lines are located by transient parameters.

According to the first embodiment, a device is known for pulse detection of places of damage to power transmission lines (N. Tarasov. Using the method of pulse reflectometry to determine damage to cable and overhead lines, www.watson.ru.). allowing to detect damage of a stable nature on lines without operating voltage, which are inhomogeneities of the wave impedance of the lines. The device consists of an OTDR meter, wires for connecting to the line, may include a prefix to increase the amplitude of the probe pulse to a level not exceeding 100 V.

The disadvantages of the described device include: low voltage of the probe pulse, insufficient to detect insulation defects; susceptibility of the impulse to the phenomena of attenuation and shape distortion; unsuitability of use for unstable damage with residual electrical strength of insulation, high values of transition resistance at the location of the defect and sensitivity to high-frequency interference.

According to the second variant, a device is known for pulse detection of places of damage to power transmission lines (N. Tarasov. Using the method of pulse reflectometry to determine damage to cable and overhead lines, www.watson.ru.). allowing to detect damage of a stable nature on lines without operating voltage, which are inhomogeneities of the wave impedance of the lines. The device consists of an OTDR meter, wires for connecting to the line, may include a prefix to increase the amplitude of the probe pulse to a level not exceeding 100 V.

The disadvantages of the described device include: low voltage of the probe pulse, insufficient to detect insulation defects; susceptibility of the impulse to the phenomena of attenuation and shape distortion; unsuitability of use for unstable damage with residual electrical strength of insulation, high values of transition resistance at the location of the defect and sensitivity to high-frequency interference.

A high-voltage pulse generator has been developed at Mosenergo to identify places of damage to power transmission lines by pulse reflectometry (Operating experience of electrical equipment in the Mosenergo system. "Energy", Moscow, 1971. - 112 pp.), Which is used in conjunction with a non-automatic location finder (NLI) to determine places of damage to the insulation of the overhead line and is a prototype according to the first embodiment. The generator includes a probe voltage signal generating unit, consisting of a step-up transformer, a storage capacitor, a thyratron switch (switching arrester), a voltage divider and two generating lines that create rectangular voltage pulses of 1 μs and 10 μs duration. With the help of such generators, the amplitude of the probe pulses sent to the line increased to 2.5-3 kV. The control of the high-voltage pulse generator was carried out directly with the help of an ICL-5 type NLI. The reflected signal was fed to the input of the NLI. The generator is connected to the overhead line through the connection filter. In this installation, a voltage transformer of the type NOM-6 is used as a source of high voltage. With a probe pulse frequency of 30 Hz, the maximum pulse amplitude is 3 kV. The duration of the pulses generated by the generator is determined by two forming lines and is 1 μs and 10 μs, the shape of the pulses is close to rectangular. The device P5-5 is used as a line heterogeneity meter. The use of a high-voltage pulse generator has significantly reduced the time to determine the location of damage on overhead power lines.

The disadvantages of the described device include: unsuitability for unstable damage to the line; insufficient probe voltage to detect insulation defects.

A high-voltage pulse generator has been developed at Mosenergo to identify places of damage to power transmission lines by pulse reflectometry (Operating experience of electrical equipment in the Mosenergo system. "Energy", Moscow, 1971. - 112 pp.), Which is used in conjunction with a non-automatic location finder (NLI) to determine places of damage to the insulation of the overhead line and is a prototype according to the second option. The generator includes a probe voltage signal generating unit, consisting of a step-up transformer, a storage capacitor, a thyratron switch (switching arrester), a voltage divider and two generating lines that create rectangular voltage pulses of 1 μs and 10 μs duration. With the help of such generators, the amplitude of the probe pulses sent to the line increased to 2.5-3 kV. The control of the high-voltage pulse generator was carried out directly with the help of an ICL-5 type NLI. The reflected signal was fed to the input of the NLI. The generator is connected to the overhead line through the connection filter. In this installation, a voltage transformer of the type NOM-6 is used as a source of high voltage. With a probe pulse frequency of 30 Hz, the maximum pulse amplitude is 3 kV. The duration of the pulses generated by the generator is determined by two forming lines and is 1 μs and 10 μs, the shape of the pulses is close to rectangular. The device P5-5 is used as a line heterogeneity meter. The use of a high-voltage pulse generator has significantly reduced the time to determine the location of damage on overhead power lines.

The disadvantages of the described device include: unsuitability for unstable damage to the line; insufficient probe voltage to detect insulation defects.

The objective of the utility model is to develop a portable device for remote location of damage to insulators of overhead power lines, the use of which would be possible for any type of damage to the insulation, including insulators with high residual electrical strength.

The technical result of applying the utility model according to the first embodiment is to increase the efficiency of the process of determining defective line insulators regardless of the value of the residual electric strength of the insulation.

The technical result of applying the utility model according to the second embodiment is to increase the efficiency of the process of determining defective line insulators regardless of the value of the residual electric strength of the insulation.

The technical result according to the first embodiment is achieved through the use of a portable device for remote location of damage to defective insulators of overhead lines, consisting of a unit for generating sounding signals, including a storage capacitor and a switch, as well as a measuring part with a voltage divider. The measuring part further includes a microprocessor associated with a voltage divider and with an information display unit. The storage capacitor of the probe signal generation block is made high-voltage, the voltage divider is connected in parallel with the high-voltage storage capacitor, and the switch is made in the form of a switching arrester. The probe signal generating unit further comprises a high-voltage charger connected to a high-voltage storage capacitor and a switching arrester, and consists of a high-frequency voltage converter, a high-voltage rectifying unit with voltage multiplication and a protective inductor.

The technical result according to the second embodiment is achieved through the use of a portable device for remote location of damage to defective insulators of overhead lines, consisting of a unit for generating sounding signals, including a storage capacitor and switch, as well as a measuring part. The measuring part includes a microprocessor, the input of which is connected to the current sensor, and the output is connected to the information display unit. The storage capacitor of the probe signal generation block is made high-voltage, the current sensor is put on the output of the high-voltage storage capacitor, and the switch is made in the form of a switching arrester. The probe signal generating unit further comprises a high-voltage charger connected to a high-voltage storage capacitor and a switching arrester, and consists of a high-frequency voltage converter, a high-voltage rectifying unit with voltage multiplication and a protective inductor.

Figure 1 shows the structural diagram of a portable device for remotely determining the location of damage to overhead line insulators according to the first embodiment, figure 2 shows the structural diagram of a portable device for remote determination of the location of damage to overhead line insulators according to the second embodiment, figure 3 shows the waveform of the probe voltage obtained as a result of computer simulation for the first embodiment, figure 4 shows the oscillogram of the probing voltage obtained as a result of of the experimental experiment on a real 10 kV line according to the first embodiment, Fig. 5 shows a current waveform during high-voltage sounding of an overhead power transmission line according to the second embodiment.

The portable device for remotely determining the location of damage to overhead line insulators according to the first embodiment consists of a unit for generating a sounding voltage signal (BSS) 1 connected to a measuring part (IC) 2. A block for generating a sounding voltage signal (BSS) 1 includes a high-voltage charger ( VZU) 3, the output of which is connected to the input of the high-voltage storage capacitor C _n , and the input of the switching spark gap FV. The high-voltage charger (VZU) 3 is portable and incorporates a high-frequency voltage converter (PNV) 4, the output of which is connected in series with the input of the high-voltage rectifier unit with voltage multiplication (BVV) 5, and the output of the high-voltage rectifier block with voltage multiplication ( BVV) 5 is connected in series with the input of the protective inductor (DZ) 6.

The measuring part (IC) 2 of the device consists of a voltage divider R1-R2, connected in parallel with the high-voltage storage capacitor C _n , a microprocessor (MP) 7, the input of which is connected by a voltage divider R1-R2, and the output is connected in series with the information display unit (BOI) 8 The information display unit (BOI) 8 can be implemented, for example, using the following technical solutions: in the form of a digital indicator, a portable computer, when using a digital indicator and a portable computer.

The portable device for remotely determining the location of damage to overhead line insulators according to the second embodiment consists of a unit for generating a sounding voltage signal (BSS) 1 connected to a measuring part (IC) 2. A block for generating a sounding voltage signal (BSS) 1 includes a high-voltage charger ( VZU) 3, the output of which is connected to the input of the high-voltage storage capacitor C _n , and the input of the switching spark gap FV. The high-voltage charger (VZU) 3 is portable and incorporates a high-frequency voltage converter (PNV) 4, the output of which is connected in series with the input of the high-voltage rectifier unit with voltage multiplication (BVV) 5, and the output of the high-voltage rectifier block with voltage multiplication ( BVV) 5 is connected in series with the input of the protective inductor (DZ) 6.

The measuring part (IC) 2 of the device consists of a current sensor TA mounted on the output of the high-voltage storage capacitor C _n , a microprocessor (MP) 7, the input of which is connected to the current sensor TA, and the output is connected in series with the information display unit (BOI) 8. Block information display (BOI) 8 can be implemented, for example, using the following technical solutions: in the form of a digital indicator, a portable computer, when using a digital indicator and a portable computer.

Consider the work of a portable device for remote location of damage to insulators of overhead lines in the first embodiment (figure 1).

Before starting a measurement on a previously disconnected power line, it is necessary to ground the casing of the high-voltage charging device (VZU) 3, the outputs of the high-voltage storage capacitor C _n and the voltage divider R1-R2. The high-voltage storage capacitor C _{n is} charged from the high-voltage charging device (BPS) 1, which is part of the probing voltage signal generating unit (BPS) 3, and is switched by a switching arrester FV to the line. The formation of high-voltage probing voltage occurs in a high-voltage charger (VZU) 3, consisting of a high-frequency voltage converter (NVD) 4, a high-voltage rectifier unit with voltage multiplication (BVV) 5 and a protective inductor (DZ) 6. Moreover, in a high-frequency voltage converter (NVD) ) 4, the voltage of the external source is converted to a high-frequency voltage with a larger amplitude, after which it is rectified in the high-voltage rectifier unit (BVV) 5 and multiplied by a plitudy and supply the high voltage storage capacitor CH through the protective choke (RS) 6, which protects the high-voltage rectifier unit (BVV) 5 large discharge current from the high voltage storage capacitor C _n. As a result of the discharge of the high-voltage storage capacitor C _n when switching to the power line, a high-voltage probing voltage with a maximum amplitude of 100% phase to 50% of the test insulation voltage of the line, propagating along the line, causes an electrical breakdown of insulation, both with residual electric strength and with low transition resistance ("metal" circuit), which will allow to detect insulation damage, including unstable nature and, in turn, will increase the efficiency of process for determining defective line insulators. At the same time, a complex oscillatory process arises in the line, including the “slow” and “fast” wave processes and independent of the magnitude of the transition resistance at the site of damage. The period of the “slow” oscillation process depends on the distance to the breakdown location, since the total inductance of the oscillatory circuit is directly proportional to the distance to the location of the defective insulators, which allows you to remotely determine the location of damage to defective insulators. Through the voltage divider R1-R2, this oscillatory process (Fig. 3) enters the measuring part (IC) 2, where it is recorded and processed by the microprocessor (MP) 7 and displayed by the information display unit (BOI) 8, consisting, for example, of a digital indicator or portable computer.

An example of a voltage waveform modeled on a computer, according to the second embodiment, is shown in Fig. 3, and also, in Fig. 4, for comparison, a voltage waveform taken from a real 10 kV line as a result of a field experiment is shown. The oscillatory processes in figure 3 and figure 4 are slightly different, due to a small deviation of the calculated parameters of the line from the experimental.

Consider the work of a portable device for remote location of damage to insulators of overhead lines according to the second option (figure 2).

Before starting a measurement on a previously disconnected power line, it is necessary to ground the housing of the high-voltage charging device (HVM) 3, the outputs of the high-voltage storage capacitor C _n and the voltage divider R1-R2. The high-voltage storage capacitor C _{n is} charged from the high-voltage charging device (BMS) 3 included in the probe sound signal generation unit (BPS) 1 and is switched using a switching arrester FV per line. The formation of high-voltage probing voltage occurs in a high-voltage charger (VZU) 3, consisting of a high-frequency voltage converter (NVD) 4, a high-voltage rectifier unit with voltage multiplication (BVV) 5 and a protective inductor (DZ) 6. Moreover, in a high-frequency voltage converter (NVD) ) 4, the voltage of the external source is converted to a high-frequency voltage with a larger amplitude, after which it is rectified in the high-voltage rectifier unit (BVV) 5 and multiplied by a plitudy and supply the high voltage storage capacitor C _H through the protective choke (RS) 6, which protects the high-voltage rectifier unit (BVV) 5 large discharge current from the high voltage storage capacitor C _n. As a result of the discharge of the high-voltage storage capacitor C _n when switching to the power line, a high-voltage probing voltage with a maximum amplitude of 100% phase to 50% of the test insulation voltage of the line, propagating along the line, causes an electrical breakdown of insulation, both with residual electric strength and with low transition resistance ("metal" circuit), which will allow to detect insulation damage, including unstable nature and, in turn, will increase the efficiency of process for determining defective line insulators. At the same time, a complex oscillatory process arises in the line, which includes the “slow” and “fast” wave processes and does not depend on the magnitude of the transition resistance at the site of damage. The period of the “slow” oscillation process depends on the distance to the breakdown location, since the total inductance of the oscillatory circuit is directly proportional to the distance to the location of the defective insulators, which allows you to remotely determine the location of damage to defective insulators. Through the current transformer TA, this oscillatory process (Fig. 5) enters the measuring part (IC) 2, where it is recorded and processed by the microprocessor (MP) 7 and displayed by the information display unit (BOI) 8, consisting, for example, of a digital indicator or a portable computer .

An example of a waveform of a current modeled on a computer according to the second embodiment is shown in FIG. As can be seen from the waveform, the oscillatory process of the current is more prone to distortion by the wave process, which can complicate the determination of the time interval that is a multiple of the oscillation period and adversely affect the measurement accuracy as a whole.

The device, as a whole, is small-sized, which allows it to be quite easily transferred during operation.

The distance to the defective insulator is determined by the period of the oscillatory process T _X voltage or current arising from high-voltage sensing, using specific line parameters and calculated expressions obtained on the basis of the initial relations for the frequency of free oscillations of the oscillatory circuit. The calculation of the distance in the device is implemented in a microprocessor (MP) 7 using various algorithms. For example, for the oscillatory circuit formed by the inductance of the loop “phase wire - ground" L _X with the capacity of the high-voltage storage capacitor C _n has the frequency of natural oscillations of the circuit ω _X determined without taking into account and taking into account the attenuation (loss) according to formulas (1) and (2), respectively :

where ω _X = 2πf _X or ω _X = 2π / T _X is the frequency of natural oscillations of the circuit formed by the capacitance of the high-voltage storage capacitor C _n and the line inductance;

T _X - period of oscillation of the transition process;

L _X = L _{0 ·} l _X , r _X = r ₀ · l _X — inductance and resistance of the line to the magnetic field at a distance l _X ;

L ₀ , r ₀ - specific inductance and line resistance.

The distance to the defective insulator is determined by the period of oscillation of the transient process Т _X , using specific line parameters and calculated expressions obtained on the basis of the initial relations for the frequency of the oscillatory circuit. The determination of the distance in the proposed method is implemented based on the following relationships:

a) for a lossless oscillatory circuit and a known specific inductance of the loop "phase wire - ground":

;

b) for the oscillatory circuit, taking into account losses and known specific inductance and active resistance of the loop "phase wire - ground":

;

where l _X is the distance to the MP, m;

T _X - period of oscillation of the transition process;

L ₀ - specific inductance of the discharge loop "phase wire - ground";

C _H is the capacitance of the storage capacitor;

r ₀ - active resistance of the discharge loop "phase wire - ground", determined taking into account the surface effect at the frequency of the oscillatory process.

The distance to the defective insulator can be determined using the ratio of the transient oscillation period T _X during the breakdown of defective insulation at a distance l _X and the transient oscillation period T _{предварительно} previously taken during sounding of the undamaged phase of the line or using the ratio of time intervals with the same frequency of the indicated oscillation periods transition process. The determination of the distance in this case is implemented on the basis of the formula:

where T _X is the period of oscillation of the transition process;

T _∑ - period of oscillations of the transition process during artificial breakdown at the end of the overhead line;

l _X is the distance to the MP, m;

l _∑ - the total length of the overhead line, which can be simplified to set the topographic length of the overhead line or more accurately determined taking into account the wire sag, as well as by preliminary measurement using pulse reflectometry or another method.

The value of l _X can be refined using correction coefficients obtained by calculation. If the total physical length of the line is known, other distance determination algorithms can be implemented using T _∑ , the period of oscillations of the transient process when simulating breakdown of insulation at one of the phases at the end of the line.

Thus, the use of the device according to the first embodiment makes it possible to identify defective insulators, including those with residual electric strength, which are almost impossible to determine by other known methods, with the exception of a complex of direct tests of VL insulators.

The main advantages of the device include the possibility of creating a high-voltage probing voltage sufficient for the breakdown of weakened insulation and the possibility of application in case of insulation damage, including an unstable one.

The application of the proposed device makes it possible to create a high-voltage probe voltage sufficient to create a breakdown at the location of the insulation defect regardless of the magnitude of the residual electric strength, which allows you to remotely determine the distance to the defective insulators.

Claims (2)

1. A portable device for remote location of damage to defective insulators of overhead lines, consisting of a unit for generating probing voltage signals, including a storage capacitor and a switch, as well as a measuring part with a voltage divider, characterized in that the storage capacitor of the unit for generating probing voltage signals is made of high voltage and the switch is made in the form of a switching arrester, the measuring part additionally includes a microprocessor, the input of which connected to the voltage divider, and the output is connected in series with the information display unit, the voltage divider is connected in parallel with the high-voltage storage capacitor, the probing voltage signal generating unit further comprises a high-voltage charger, the output of which is connected to the input of the high-voltage storage capacitor and the input of the switching spark gap, and consists of high-frequency voltage converter, the output of which is connected in series with the input of the high-voltage rectifier unit with voltage multiplication, and the output of the high-voltage rectifier unit with voltage multiplication is connected in series with the input of the protective inductor. 2. A portable device for remote location of damage to defective insulators of overhead lines, consisting of a unit for generating probing voltage signals, including a storage capacitor and a switch, as well as a measuring part, characterized in that the storage capacitor of the unit for generating probing voltage signals is made high-voltage, and the switch made in the form of a switching arrester, the measuring part includes a microprocessor, the input of which is connected to a current sensor, and the output is is connected to the information display unit, the current sensor is put on the output of the high-voltage storage capacitor, the probing voltage signal generation unit additionally contains a high-voltage charger, the output of which is connected to the input of the high-voltage storage capacitor and the input of the switching arrester, and consists of a high-frequency voltage converter, the output of which is sequentially connected to the input of the high-voltage rectifier unit with voltage multiplication, and the output is high ovoltnogo rectifier unit with a voltage multiplying successively connected to the input of the protective choke.