An uninterrupted DC ice-melting device

A technology of DC ice melting and DC conversion circuit, which is applied in the installation of cables, a single AC network with different frequencies, electrical components, etc., can solve the problems of long ice melting time, low practical feasibility and large workload, etc. To achieve the effect of simple control method, strong ice melting pertinence and high reliability

Active Publication Date: 2016-03-02
STATE GRID CORP OF CHINA +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage is that only two phases can be melted at a time, the time for melting ice is long, the workload of knife switch operation and manual setting of short-circuit lines is large, and power failure is required.
At present, the cost of large-capacity voltage source converters based on fully controlled devices is very high, so this method is not feasible in practice
[0006] To sum up, in the existing ice-melting technology, the power-off ice-melting method affects the normal power supply of the line, and the manual connection of the short-circuit line and the power-off operation are heavy and take a long time; It does not have the conditions for general promotion, and it is necessary to seek a new type of non-stop ice melting technology with high cost performance

Method used

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  • An uninterrupted DC ice-melting device
  • An uninterrupted DC ice-melting device
  • An uninterrupted DC ice-melting device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0050] Non-stop DC deicing device based on on-load tap changer, as attached Figure 6 shown. The device includes a voltage regulating circuit, an AC-DC conversion circuit, a resonant circuit I and a resonant circuit II; the voltage regulating circuit is an on-load voltage regulating transformer; its primary side is connected to the power supply bus in the station, such as a 35kV bus in a typical 220kV substation, Its secondary side is connected with the AC-DC conversion circuit and the resonant circuit I in turn.

[0051] The AC-DC conversion circuit includes an uncontrollable rectification circuit or a controllable rectification circuit. In this embodiment, a diode uncontrollable rectification circuit is used. and ice-melting current demand to inject DC voltage into the line to obtain ice-melting current.

[0052] A resonant circuit I is connected between the positive and negative poles of the DC end of the AC-DC conversion circuit. When the device injects DC current into t...

Embodiment 2

[0056] This embodiment is basically the same as Embodiment 1, but the difference is that the main circuit structure is based on the power electronic voltage regulating circuit, as shown in the attached Figure 7 shown. The rectifier transformer isolates the power supply bus, steps down the voltage, rectifies it through diodes, and then inverts the DC voltage into AC voltage through the VSC. It is then connected in series to the ice-melting circuit through a step-up transformer and a diode rectifier bridge. Through diode uncontrolled rectification and VSC active inverter, the VSC AC output voltage is flexible and quickly adjustable to obtain an AC voltage that can vary in a wide range, and then through the transformer step-up and uncontrolled rectification circuit AC-DC conversion, Get the DC voltage needed to melt the ice.

[0057] Suppose the input voltage of the voltage regulating circuit is Uv1, the transformation ratio of the first stage transformer is k1, the first stag...

Embodiment 3

[0063] This embodiment is basically the same as Embodiment 1, but the difference lies in that the main circuit structure is based on the power electronic voltage regulation circuit, using voltage source converters connected back to back, and adding a tap changer, such as the attached Figure 8 shown. When there is a demand for ice melting, the rectifier transformer isolates the power supply bus, steps down the voltage and rectifies it through the voltage source converter VSC1, and then inverts the DC voltage into an AC voltage through VSC2. It is then connected in series to the ice-melting circuit through a step-up transformer and a diode rectifier bridge. Through diode uncontrolled rectification and VSC active inverter, the VSC AC output voltage is flexible and quickly adjustable to obtain an AC voltage that can vary in a wide range, and then through the transformer step-up and uncontrolled rectification circuit AC-DC conversion, Get the DC voltage needed to melt the ice.

...

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PUM

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Abstract

An uninterrupted direct current deicing device. The deicing device is mounted inside a substation at one side of a line, and all operations can be implemented for the deicing device inside the substation. The deicing device comprises a voltage regulation circuit, an alternating current / direct current conversion circuit, a first resonant circuit, and a second resonant circuit. One end of the voltage regulation circuit is connected to a power supply bus in the substation, and the other end is connected to the alternating current / direct current conversion circuit and the first resonant circuit successively; the second resonant circuit is configured between a sectionalized bus where a non-deicing line resides and a sectionalized bus where a deicing line resides in the substation. In the deicing device, without affecting normal power supply, a direct current deicing current is superposed on a deicing line, and the deicing current is made to circulate only in the deicing line and does not interfere with an important device such as a main transformer inside the substation. The deicing device achieves high deicing efficiency and has a small capacity.

Description

technical field [0001] The invention belongs to the technical field of power electronics, and in particular relates to a non-stop DC ice-melting device. Background technique [0002] Icing of power lines often occurs in some areas in winter, which brings serious disasters to the power grid. The methods to solve the problem of icing are divided into mechanical deicing or thermal deicing, and thermal deicing is divided into two types: power-off de-icing and non-power-off de-icing. [0003] Thermal deicing in power outages has been applied in power grids, and the implementation methods include AC short-circuit up-current deicing and DC current deicing. In the former, 2 to 3 ice-melting lines are connected in series through knife switch operation, one end is artificially short-circuited, and the other end is connected to an AC power supply for short-circuit ice-melting. Its advantage is that no special equipment is needed, and the production site is practical. The disadvantag...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): H02G7/16
CPCH02G1/02H02G7/16H02J3/02
Inventor荆平周飞宋洁莹邱宇峰苏雪源詹建荣陈颖
OwnerSTATE GRID CORP OF CHINA