CN111799738A - Live automatic ice-melting system and ice-melting method for power distribution network overhead cables - Google Patents

Abstract

The invention discloses a live automatic ice-melting system and an ice-melting method for an overhead cable of a power distribution network. The system comprises: an automatic ice-melting input device, a first insulated wire connected to the output side of the automatic ice-melting input device, and The second insulated wire; the first insulated wire and the second insulated wire are used for winding on the distribution network overhead cable to be melted, and the ends of the first insulated wire and the second insulated wire are short-circuited. The method includes: monitoring and obtaining the ice coating thickness, temperature, humidity and wind speed values on the overhead cables of the distribution network, and judging whether the ice coating will melt according to the ice coating thickness, temperature, humidity and wind speed values; if the ice coating thickness reaches a warning value and the When the ice coating does not melt, the automatic input device for ice melting is controlled to output voltage and current to the first insulated wire and the second insulated wire wound on the overhead cable of the distribution network to be melted, and the ice starts to be melted. The present invention can realize the automatic switching of ice melting, and the overhead cable is not required to be cut off when the ice is melting, and the charged ice melting can be realized.

Description

Live automatic ice-melting system and ice-melting method for power distribution network overhead cables

technical field

The invention relates to the technical field of power grid ice melting, in particular to a live automatic ice melting system and an ice melting method for overhead cables of power distribution networks.

Background technique

The frequent occurrence of rain, snow and freezing disasters can cause damage to the power grid. The distribution network lines are more prone to ice disasters due to their multiple points and wide areas, and they are located in many micro-topography and micro-meteorological areas, which may lead to large-area downed poles and disconnection, which seriously affects the reliability of power supply. In recent years, in order to improve the insulation capacity and prevent personal electric shock, most of the distribution network has been transformed from the original overhead bare wires into overhead cables. The ice melting problem of overhead cables has become a new challenge.

At present, researchers have carried out a lot of research on the current ice melting technology of overhead bare conductors, and have produced good results, but the ice melting of overhead cables has not been studied. Due to the protection of the insulating layer, the overhead cable has poor heat dissipation, greater heat generation, and smaller current-carrying capacity than bare wires. If the overhead cable uses electric current to melt ice, the current is too small to reach the required calorific value so that the ice coating on the outer surface of the cable cannot be melted, and the current is too large and affects the performance of the insulating layer.

Therefore, the existing current ice melting technology cannot be applied to overhead cables. There is an urgent need to carry out research on new ice melting technology for overhead cables in distribution networks.

SUMMARY OF THE INVENTION

The invention provides an electrified automatic ice melting system and an ice melting method for overhead cables of power distribution network, which are used to solve the technical problem that the existing current ice melting technology cannot be directly used for overhead cables.

In order to solve the above-mentioned technical problems, the technical scheme proposed by the present invention is:

A live automatic ice melting system for overhead cables of power distribution network, comprising: an automatic ice melting input device, a first insulated wire and a second insulated wire connected to the output side of the automatic ice melting input device; the first insulated wire and the The second insulated wire is used for winding on the overhead cable of the power distribution network to be melted, and the ends of the first insulated wire and the second insulated wire are short-circuited.

As a further improvement of the method of the present invention:

The system also includes: an ice melting automatic control device and an ice coating/weather monitoring device, and the ice melting automatic control device is respectively connected with the automatic ice melting input device and the ice coating/weather monitoring device;

Ice coating/meteorological monitoring device, which is used to monitor and obtain the thickness of ice coating, temperature, humidity and wind speed on the overhead cable and send it to the automatic control device for ice melting;

The ice melting automatic control device is used to receive the ice coating thickness, temperature, humidity and wind speed values, and judge whether the ice coating thickness reaches the warning value, and judge whether the ice coating will melt according to the ice coating thickness, temperature, humidity and wind speed value; When the thickness of the ice coating reaches the warning value and the ice coating will not melt, the ice-melting automatic input device is controlled to start the ice-melting.

The icing/meteorological monitoring device is also used to continue to monitor the thickness of the icing on the overhead cables of the distribution network during the thawing process and send it to the automatic ice thawing control device;

The ice-melting automatic control device is also used to control the ice-melting automatic input device to stop the output to the first insulated wire and the second insulated wire by monitoring and judging that the ice coating on the overhead cable of the power distribution network falls off. Disconnect the ice melting power source from the first insulated wire and the second insulated wire to end the ice melting.

The system also includes: an ice-melting power source with adjustable output voltage, which is connected with the automatic ice-melting input device to provide power for the output of ice-melting.

The ice-melting automatic control device is also connected with the ice-melting power source, so as to turn on the ice-melting power source when the ice-melting automatic input device is controlled to start the ice-melting, and turn off the ice-melting power source after the ice-melting is completed.

The present invention also provides an ice-melting method for using the above-mentioned live automatic ice-melting system for power distribution network overhead cables to melt ice for distribution network overhead cables, comprising the following steps:

Obtain the ice thickness, temperature, humidity and wind speed values on the overhead cables of the distribution network by monitoring the ice coating/meteorological monitoring device;

And judge whether the ice coating thickness reaches the warning value, and judge whether the ice coating will melt according to the ice coating thickness, temperature, humidity and wind speed value;

If the thickness of the ice coating reaches the warning value and the ice coating will not melt, control the ice melting automatic input device to output voltage and current to the first insulated wire and the second insulated wire wound on the overhead cable of the distribution network to be melted, and start melting. ice.

Preferably, the method also includes the following steps:

During the ice melting process, continue to monitor the thickness of the ice coating on the overhead cables of the distribution network through the ice coating/meteorological monitoring device;

When it is detected that the ice coating on the overhead cable of the distribution network falls, the automatic ice melting control device controls the ice melting automatic input device to stop the output to the first insulated wire and the second insulated wire, and the ice melting power supply and the first insulated wire are connected. Disconnect from the second insulated wire to end the ice melt.

Preferably, it is judged whether the icing will melt according to the thickness of the icing, temperature, humidity and wind speed, including:

If the temperature is greater than 0°C, no matter how high the humidity is, the icing will melt, the thickness of the icing will decrease, and the smaller the wind speed, the faster the decrease;

If the temperature is less than or equal to 0°C and the humidity is less than 80%, the icing will be maintained and the thickness of the icing will remain unchanged;

If the temperature is less than or equal to 0°C and the humidity is greater than or equal to 80%, the icing will increase, the thickness of the icing will increase, and the greater the wind speed, the faster the increase.

The present invention has the following beneficial effects:

1. The live automatic ice-melting system for power distribution network overhead cables of the present invention can be realized by loading the first insulated wire and the second insulated wire with ice-melting current, and by winding it on the distribution network overhead cable to be ice-melted. The ice melting of the overhead cable of the distribution network directly acts on the ice-covered layer of the overhead cable of the distribution network due to the heat generation through the insulating layers of the first insulated wire and the second insulated wire, so that the performance of the insulating layer of the overhead cable will not be affected. At the same time, there is no need for overhead cable power failure during ice melting, which can realize electrified ice melting and ensure continuous power supply during ice coating.

2. In the preferred solution, the present invention is used for the live automatic ice melting system and ice melting method for overhead cables of distribution network, which can automatically start ice melting according to the thickness of ice coating and meteorological factors, without manual wiring and operation, which is convenient and fast. Realize the live automatic ice melting of the overhead cable 1 of the distribution network.

In addition to the objects, features and advantages described above, the present invention has other objects, features and advantages. The present invention will be described in further detail below with reference to the accompanying drawings.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide further understanding of the present invention, and the exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached image:

1 is a schematic structural diagram of a live automatic ice-melting system for overhead cables in a power distribution network according to a preferred embodiment of the present invention;

FIG. 2 is a schematic flow chart of a method for automatic ice-melting with electricity used for the overhead cable 1 of a power distribution network according to a preferred embodiment of the present invention.

The symbols in the figure represent:

1. Overhead cable for distribution network; 2. First insulated wire; 3. Second insulated wire; 4. Automatic ice-melting input device; 5. Ice-melting automatic control device; 6. Ice-melting power supply; 7. Ice coating/weather monitoring device.

Detailed ways

The embodiments of the present invention are described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways as defined and covered by the claims.

Referring to FIG. 1, the live automatic ice melting system for power distribution network overhead cables of the present invention includes: an automatic ice melting input device 4, a first insulated wire 2 connected to the output side of the automatic ice melting input device 4 and a second The insulated wire 3; the first insulated wire 2 and the second insulated wire 3 are used for winding on the distribution network overhead cable 1 to be melted, and the ends of the first insulated wire 2 and the second insulated wire 3 are short-circuited. With the above structure, the ice-melting current can be loaded on the first insulated wire 2 and the second insulated wire 3, and the ice-melting of the distribution network overhead cable 1 can be realized by being wrapped around the distribution network overhead cable 1 to be ice-melted. The insulating layers of the first insulated wire 2 and the second insulated wire 3 directly act on the ice-covered layer of the overhead cable 1 of the distribution network, so that the performance of the insulating layer of the overhead cable 1 will not be affected. At the same time, the overhead cable 1 does not need to be powered off during ice melting, which can realize charged ice melting and ensure continuous power supply during the icing period.

During implementation, the model and length of the first insulated wire 2 and the second insulated wire 3 are selected according to the model and length of the ice-melting overhead cable 1 , for example, 1000V, 4 mm ² wires.

During implementation, the system can also be provided with an ice-melting power supply 6 with an adjustable output voltage. The ice-melting power supply 6 is connected to the automatic ice-melting input device 4 to provide power for the ice-melting output. The ice-melting power supply 6 can be designed to have an adjustable output voltage. The power supply can meet the ice-melting requirements of different lengths and different types of distribution network overhead cables 1. The maximum voltage and capacity can be selected according to the maximum length of the ice-melting distribution network overhead cables 1 (for example, the power of 30kW and the output of 200-1000V can be selected. Adjustable power supply), its output voltage can be pre-adjusted according to the model and length of the overhead cable 1 of the ice-melting distribution network.

In this embodiment, in order to realize automatic electrified ice melting, the system may further include: an ice melting automatic control device 5 and an ice coating/weather monitoring device 7, the ice melting automatic control device 5 is respectively connected with the automatic ice melting input device 4 and the ice coating/meteorological monitoring device 7. The meteorological monitoring device 7 is connected; the icing/meteorological monitoring device 7 is used to monitor and obtain the thickness, temperature, humidity and wind speed of the ice coating on the overhead cable 1 of the power distribution network and send it to the automatic ice melting control device 5; the ice melting automatic control device 5 is used to receive the ice thickness, temperature, humidity and wind speed values, and judge whether the ice thickness reaches the warning value, and judge whether the ice will melt according to the ice thickness, temperature, humidity and wind speed; if the ice thickness reaches the warning value When the value is reached and the ice coating will not melt, turn on the ice melting power source 6, and control the ice melting automatic input device to start the ice melting.

Further, in order to automatically end the ice melting, the ice coating/meteorological monitoring device 7 in this embodiment can also be used to continue to monitor the thickness of the ice coating on the overhead cable 1 of the power distribution network during the ice melting process and send it to the automatic ice melting control. Device 5; the ice melting automatic control device 5 is also used to control the ice melting automatic input device to stop the first insulated wire 2 and the first insulated wire 2 through the ice melting automatic control device 5 after the ice coating on the overhead cable 1 of the distribution network is judged by monitoring. The second insulated wire 3 is output, the ice melting power source 6 is disconnected from the first insulated wire 2 and the second insulated wire 3, the ice melting is completed, and the ice melting power source 6 is turned off.

The ice coating/weather monitoring device 7 of this embodiment is powered by solar panels and batteries, and its input side is installed on the outer surface of the overhead cable 1 or on the tower, so as to obtain the thickness, temperature, humidity and wind speed of the ice coating on the overhead cable 1 in real time. and other meteorological parameters.

Referring to Figure 2, the present invention also provides a method for melting ice using the above-mentioned live automatic ice-melting system for power distribution network overhead cables to melt the distribution network overhead cables 1, comprising the following steps:

S100: Monitor and obtain the ice thickness, temperature, humidity and wind speed values on the overhead cable 1 of the power distribution network through the ice coating/meteorological monitoring device 7. During implementation, a tension sensor or camera can be installed on the overhead cable 1 or a tower, and the ice-covered thickness of the overhead cable 1 can be obtained by force analysis or graphic analysis. Temperature and humidity, wind speed and wind direction sensors can be installed on the tower to monitor temperature, humidity and wind speed values in real time.

S200: and determine whether the thickness of the ice coating reaches the warning value, and determine whether the ice coating will melt according to the thickness of the ice coating, temperature, humidity and wind speed values. When the overhead cable 1 is designed and constructed, it is designed to withstand a certain thickness of ice (that is, the design ice thickness). For example, when the design ice thickness is 15mm, the warning value can be set to 60% of the design ice thickness during implementation, that is, the warning The value is 9mm. At the same time, if the ice coating will melt naturally, there is no need to start the ice melting. Therefore, it can be judged whether the ice coating will melt naturally according to the monitored temperature, humidity and wind speed values combined with the thickness of the ice coating. If the temperature is greater than 0°C, no matter how high the humidity is, the ice coating will melt, and the thickness of the ice coating will decrease, and the smaller the wind speed, the faster the reduction; No change; if the temperature is less than or equal to 0°C and the humidity is greater than or equal to 80%, the icing will increase, the thickness of the icing will increase, and the greater the wind speed, the faster the increase.

S300: If the ice coating thickness reaches the warning value and the ice coating will not melt, control the ice melting automatic input device to output the output to the first insulated wire 2 and the second insulated wire 3 wound on the distribution network overhead cable 1 to be melted. Voltage and current, start melting ice. During implementation, the automatic ice melting control device 5 can send a signal to start or stop the ice melting to the automatic ice melting input device 4, thereby controlling the automatic ice melting input device 4 to input or withdraw from the ice melting power supply 6, without manual wiring and operation, convenient. It is fast, and there is no need for power failure of the overhead cable 1, so that the ice melting can be realized.

S400: During implementation, during the ice melting process, continue to monitor the thickness of the ice coating on the overhead cable 1 of the distribution network through the ice coating/meteorological monitoring device 7; The ice-melting automatic control device 5 controls the ice-melting automatic input device to stop outputting to the first insulated wire 2 and the second insulated wire 3, and disconnects the ice-melting power supply 6 from the first insulated wire 2 and the second insulated wire 3. The ice power source 6 is disconnected from the insulated wire (or the ice melting power source 6 is turned off), and the ice melting is ended.

To sum up, the live automatic ice-melting system and ice-melting method for overhead cables of power distribution network of the present invention can automatically start ice-melting according to the thickness of ice coating and meteorological factors, without manual wiring and operation, which is convenient and quick. The live automatic ice melting of the overhead cable 1 of the distribution network can be realized.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. An automatic de-icing system for live power distribution network overhead cables, comprising: an automatic ice melting input device (4), a first insulated wire (2) and a second insulated wire (3) which are connected to the output side of the automatic ice melting input device (4); the first insulated wire (2) and the second insulated wire (3) are used for being wound on the power distribution network overhead cable 1 to be melted with ice, and the tail ends of the first insulated wire (2) and the second insulated wire (3) are in short circuit.

2. The live automatic ice melting system for overhead cables of a power distribution network of claim 1, further comprising: the ice-melting automatic control device (5) and the ice-coating/meteorological monitoring device (7), wherein the ice-melting automatic control device (5) is respectively connected with the automatic ice-melting input device (4) and the ice-coating/meteorological monitoring device (7);

the icing/meteorological monitoring device (7) is used for monitoring and acquiring icing thickness, temperature, humidity and wind speed values on the overhead cable 1 and sending the icing thickness, temperature, humidity and wind speed values to the automatic ice melting control device (5);

the ice-melting automatic control device (5) is used for receiving the ice-coating thickness, the temperature, the humidity and the wind speed value, judging whether the ice-coating thickness reaches a warning value or not, and judging whether the ice-coating is melted or not according to the ice-coating thickness, the temperature, the humidity and the wind speed value; and controlling the automatic ice melting input device to melt ice if the ice coating thickness reaches a warning value and the ice coating cannot be melted.

3. The live automatic ice melting system for overhead cables of a power distribution network of claim 2,

the icing/meteorological monitoring device (7) is also used for continuously monitoring the icing thickness on the overhead cable 1 of the power distribution network and sending the icing thickness to the automatic ice melting control device (5) in the ice melting process;

and the automatic ice melting control device (5) is also used for controlling the automatic ice melting input device to stop outputting to the first insulated wire (2) and the second insulated wire (3) through the automatic ice melting control device (5) after the ice coating on the power distribution network overhead cable 1 is judged to drop through monitoring, disconnecting the ice melting power supply (6) from the first insulated wire (2) and the second insulated wire (3), and ending ice melting.

4. The live automatic de-icing system for overhead cables of a power distribution network according to any one of claims 1 to 3, characterized in that it further comprises: and the ice melting power supply (6) is adjustable in output voltage, and the ice melting power supply (6) is connected with the automatic ice melting input device (4) to provide power for ice melting output.

5. The live-line automatic ice melting system for the overhead cables of the power distribution network as claimed in claim 4, wherein the automatic ice melting control device (5) is further connected with the ice melting power supply (6) to turn on the ice melting power supply (6) when controlling the automatic ice melting switching device to start melting ice and turn off the ice melting power supply (6) after the end of melting ice.

6. A method for melting ice on the overhead cable 1 of the power distribution network by using the electrified automatic ice melting system for the overhead cable of the power distribution network as claimed in any one of claims 2 to 5, which is characterized by comprising the following steps:

the icing thickness, the temperature, the humidity and the wind speed value on the overhead cable 1 of the power distribution network are monitored and obtained through an icing/meteorological monitoring device (7);

judging whether the thickness of the ice coating reaches a warning value or not, and judging whether the ice coating can be ablated or not according to the thickness of the ice coating, the temperature, the humidity and the wind speed value;

and if the thickness of the coated ice reaches the warning value and the coated ice cannot be melted, controlling the automatic ice melting input device to output voltage and current to the first insulated wire (2) and the second insulated wire (3) wound on the power distribution network overhead cable 1 to be melted, and starting to melt the ice.

7. A method of melting ice according to claim 6, further comprising the steps of:

in the ice melting process, the ice coating thickness on the overhead cable 1 of the power distribution network is continuously monitored through an ice coating/meteorological monitoring device (7);

when the situation that the ice coating on the overhead cable 1 of the power distribution network falls is monitored, the ice melting automatic input device is controlled by the ice melting automatic control device (5) to stop outputting to the first insulated wire (2) and the second insulated wire (3), the ice melting power supply (6) is disconnected from the first insulated wire (2) and the second insulated wire (3), and ice melting is finished.

8. A method of melting ice according to claim 6 or 7, wherein said determining if said ice coating will ablate from said values of ice coating thickness, temperature, humidity and wind speed comprises:

if the temperature is higher than 0 ℃, no matter how high the humidity is, the ice coating can be ablated, the ice coating thickness is reduced, and the wind speed is reduced faster as the wind speed is smaller;

if the temperature is less than or equal to 0 ℃ and the humidity is less than 80%, the ice coating can be maintained, and the ice coating thickness is unchanged;

if the temperature is less than or equal to 0 ℃ and the humidity is greater than or equal to 80%, the icing will grow, the thickness of the icing will increase, and the wind speed will increase faster the greater.

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