RU2145118C1 - Device for checking ice load of electric power transmission lines - Google Patents

Abstract

FIELD: power plants. SUBSTANCE: transducers, which are located in points for checking ice load on wire and rope, convert signals from outputs of ice load detectors into respective voltage of direct current of same or opposite polarity. Periodic switches of power supply of transducers in points of ice load detectors and presence of commutator of channels in receiving station provides transmission of output voltage of transducers through rope-earth transmission channel into inputs of respective receivers which monitor ice load of phase wires and lightning-protection rope. EFFECT: increased functional capabilities due to simultaneous monitoring of ice load of wire and lightning-protection rope in order to control equipment for thawing ice on wires and rope. 3 dwg

Description

 The invention relates to the electric power industry and can be used for continuous monitoring of ice load on wires and cables of power lines.

 A device is known for monitoring icing load at several points of the network at monitored points with contact icing load sensors and transmitting to the dispatching station an alarm signal for each sensor with a constant current signal of appropriate duration (with time-pulse coding) according to the phase-ground circuit [1]. The disadvantages of this device are the low reliability of the contact sensor, the impossibility of continuous monitoring of ice load, as well as the need to use synchronization units at the monitored and dispatch points to recognize at which point in the network the contact sensor of the ice load was triggered.

 A device with a proximity sensor for continuous monitoring of icy loads on wires or cables of power lines with the transmission of information by DC voltage according to the scheme "insulated lightning protection cable - ground" [2]. This device, which is the closest analogue, contains a receiving unit, the input of which is shunted by the first capacitor and connected between the first ground terminal and a choke with a terminal for connecting to the ground cable of the power line, and at least one signaling device equipped with an ice load sensor a converter of the output signal of the icing load sensor to a proportional DC voltage, the output of which is shunted by a second capacitor connected between the second ground terminal and the primary winding of the transformer with a terminal for connecting to an earth cable isolated from the ground, and the input is connected to the secondary winding of the transformer.

 The voltage of the receiving unit of the analog device is determined by the larger of the voltage values at the output of the signaling devices, therefore, the described analog device does not allow to recognize where the ice load is monitored - on the wire or on the power line cable, which is necessary to control various ice melting installations on wires and cables.

 The invention is aimed at solving the problem of simultaneous continuous monitoring of ice load on the wire and cable with the transmission of information by DC voltage according to the scheme "insulated lightning protection cable - ground".

 The specified technical result is ensured by the fact that, in the device containing the receiving unit, the first capacitor connected between the first ground terminal and the inductor with the terminal for connection to the insulated lightning protection cable of the power line and made with an icing load sensor on the wire signal device equipped with a sensor output signal converter ice load into a proportional DC voltage, the output of which is connected to a second capacitor connected between the second terminal grounding and the primary winding of the transformer with the terminal of the day connecting to the lightning protection cable of the power line, and the input is connected to the secondary winding of the transformer, an additional second receiving unit and an electronic channel switch connected between the first capacitor and the inputs of both receiving units are added, and at the location of the sensors the ice the load on the wire and cable additionally introduced a second signaling device containing a signal converter of the icing load sensor into a DC voltage, two istornyh key and a frequency divider, wherein outputs of sensors are connected in parallel to the second capacitor, and the input sensors are connected to the secondary winding of the transformer through the thyristor keys, control inputs of which are connected to the outputs of the frequency divider paraphase voltage sensors.

 The essence of the claimed invention is illustrated by the functional diagram of the device shown in FIG. 1; in FIG. Figures 2 and 3 show examples of the implementation of the channel switch at the place of information reception.

 The device of FIG. 1 contains two receiving units 1 and 2 at the place of receiving information for monitoring icing load on the wire and cable, respectively. Their inputs through the electronic switch of channels 3 are shunted by the first capacitor 4 connected between the first ground terminal 5 and the inductor 6 with the terminal for connection to the ground wire 7 of the power transmission line isolated from the earth. A transformer 8 is installed at the location of the ice load sensors on the wire and the cable, the primary winding of which is connected in series with the second capacitor 9 between the cable 7 and the second ground terminal 10. The frequency divider of the supply voltage 11 is connected to the secondary winding of the transformer 8 and through thyristor switches 12 and 13 ice load signaling devices on wire 14 and on cable 15, respectively. Each of the signaling devices includes an icing load sensor and a converter of the sensor output signal to a DC voltage proportional to it. The outputs of the signaling devices 14 and 15 are connected to the second capacitor 9. The control inputs of the thyristor switches 12 and 13 are connected to the paraphase outputs of the frequency divider 11.

 The device operates as follows.

 When the ice load on the wire or cable increases, the output constant voltage of the signaling devices 14 and 15, respectively, increases, the supply voltage of which is periodically turned on and off using thyristor switches 12 and 13 with a frequency specified by the frequency divider 11. As a result, the second capacitor 9 is periodically charged by the output signaling voltage 14 or 15.

 Simultaneous continuous monitoring of the ice load on the wire and cable of the power line is provided in the device by transmitting information by DC voltage of different polarity or one polarity, but in different ranges of its change. In this case, information about the value of the ice load on the wire is transmitted in the first case by voltage of positive polarity, and in the second - by voltage of positive polarity in the range 0-U1; information on the magnitude of the hungry cable load is transmitted in the first case by voltage of negative polarity, and in the second by voltage of positive polarity in the range U2 - U3, moreover, U2> U1. With this method of transmitting information about the icy load on the wire and cable, no synchronization is required in the operation of the equipment installed at the place of receiving information and at the location of the sensors on the power line, which greatly simplifies the equipment and increases the reliability of its operation.

 Thus, when transmitting information about the magnitude of the ice load with a DC voltage of different polarity, the capacitor 9 and, therefore, the capacitor 4 will be periodically charged with a voltage of different polarity. At the same time, it is sufficient to use the diode circuit shown in FIG. 2, and the input of the receiving unit 1 receives a voltage of positive polarity proportional to the ice load on the wire, and the input of the receiving unit 2 receives a voltage of negative polarity proportional to the ice load on the cable.

 When transmitting information about the magnitude of the ice load with a DC voltage of the same polarity with different ranges of its change for a wire and a cable, the circuit shown in FIG. 3. In this case, the channel 3 switch consists of two electronic keys 16 and 17 connected between the capacitor 4 and the input of the corresponding receiving unit 1 or 2. The electronic key inputs are connected to the paraphase outputs of the comparator 18, which controls the voltage on the capacitor 4. If the capacitor 4 is charged the output voltage of the first detector 14, varying in the range 0-U1, then the comparator 18 is in an unused state, the electronic switch 17 is closed, and the electronic switch 16 is open, and the voltage from the capacitor 4 is fed to the input of the first th receiving unit 1, which controls the icing load on the wire. If the capacitor 4 is charged by the output voltage of the second detector 15, varying in the range U2-U3, then the comparator 18 is in the activated state, the electronic key 16 is closed, and the electronic key 17 is open, and the voltage from the capacitor 4 is supplied to the input of the second receiving unit 2, which controls icy load on the cable.

Sources of information
1. Dyakov A.F., Levchenko I.I. The experience of dealing with icing on power lines // Electric stations. 1982. N1. S.50-54.

 2. A. S. 1539885 (USSR). Device for monitoring ice load on wires or cables of power lines / Yu.I. Lyskov, V. S. Molodtsov, M. M. Mid // 01/30/90. Bull. N4.

Claims (1)

 A device for controlling the icy load of power lines, comprising a receiving unit, a first capacitor connected between the first ground terminal and a choke with a terminal for connecting to an insulated lightning protection cable of power lines, and a signal device made with an icing load sensor equipped with a converter for output of the icing load sensor to a proportional DC voltage, the output of which is connected to a second capacitor connected between the second terminal is grounded and a primary winding of a transformer with a terminal for connecting power lines to a lightning protection cable, characterized in that a second receiving unit and an electronic channel commutator are inserted into the device, the inputs of the receiving units are connected to the first capacitor via an electronic switch, and a second signaling device with an ice load sensor is additionally introduced equipped with a converter of the output signal of the icing load sensor to a DC voltage, two thyristor switches and a frequency divider alizatorov, wherein the outputs of sensors are connected in parallel to the second capacitor, and their inputs are connected to the secondary winding of the transformer through the thyristor keys, control inputs of which are connected to the outputs of the paraphase frequency divider connected to the secondary winding of the transformer.

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