CN214590490U - Variable-frequency controllable current source ice melting device - Google Patents
Variable-frequency controllable current source ice melting device Download PDFInfo
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- CN214590490U CN214590490U CN202121033766.1U CN202121033766U CN214590490U CN 214590490 U CN214590490 U CN 214590490U CN 202121033766 U CN202121033766 U CN 202121033766U CN 214590490 U CN214590490 U CN 214590490U
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Abstract
The application discloses controllable current source ice-melt device of variable frequency includes: the voltage source type converter valve comprises a first voltage source type converter valve group, a second voltage source type converter valve group and a third voltage source type converter valve group; the input end of the first voltage source type converter valve group is connected with the input end of the alternating current power supply, and the output end of the first voltage source type converter valve group is connected with the first phase ice melting circuit; the input end of the second voltage source type converter valve group is connected with the input end of the alternating current power supply, and the output end of the second voltage source type converter valve group is connected with the second phase ice melting circuit; the input end of the third voltage source type converter valve group is connected with the input end of the alternating current power supply, and the output end of the third voltage source type converter valve group is connected with the third phase ice melting circuit; the isolation knife switch is arranged on the first phase ice melting circuit, the second phase ice melting circuit and the third phase ice melting circuit and used for controlling the on-off of the circuits. The method and the device can solve the technical problems that the existing ice melting technology is poor in controllability and limited in application occasions, and therefore the ice melting efficiency is low.
Description
Technical Field
The application relates to the technical field of power transmission line ice melting, in particular to a variable-frequency controllable current source ice melting device.
Background
Among various natural disasters suffered by an electric power system, ice disaster is one of the most serious threats, ice coating damages electric power equipment and interrupts power supply, uncontrollable ice shedding enlarges the disasters, and the ice coating causes large-area paralysis of domestic and foreign electric grids for many times. With the continuous improvement of the modernization level, the dependence degree of the whole society on electric power is higher and higher, and higher requirements on electric power supply are also put forward. In recent years, various global meteorological disasters are more frequent, extreme weather and climate events are more abnormal, the loss and the influence of an electric power system caused by ice disasters are more serious, the damage degree is stronger and more complex, the coping difficulty is higher and more, and timely, quick, controllable and safe deicing means are urgently needed for a power grid.
The biggest influence of ice coating on the lines of the power system is equipment damage, which causes interruption of power supply and communication, further causes large-area power failure and is difficult to recover power. The existing deicing technology has poor controllability, limited application occasions and low actual efficiency in the deicing process.
SUMMERY OF THE UTILITY MODEL
The application provides a variable-frequency controllable current source ice melting device which is used for solving the technical problems that the existing ice melting technology is poor in controllability and limited in application occasions, and therefore ice melting efficiency is low.
In view of the above, a first aspect of the present application provides a variable frequency controllable current source ice melting apparatus, including: a voltage source type converter valve and an isolation knife switch;
the voltage source type converter valve comprises a first voltage source type converter valve group, a second voltage source type converter valve group and a third voltage source type converter valve group;
the input end of the first voltage source type converter valve group is connected with the input end of an alternating current power supply, and the output end of the first voltage source type converter valve group is connected with the first phase ice melting circuit;
the input end of the second voltage source type converter valve group is connected with the input end of the alternating current power supply, and the output end of the second voltage source type converter valve group is connected with the second phase ice melting circuit;
the input end of the third voltage source type converter valve group is connected with the input end of the alternating current power supply, and the output end of the third voltage source type converter valve group is connected with the third phase ice melting circuit;
the isolation knife switch is arranged on the first-phase ice melting circuit, the second-phase ice melting circuit and the third-phase ice melting circuit and used for controlling the on-off of the circuits.
Optionally, the first voltage source converter valve group, the second voltage source converter valve group, and the third voltage source converter valve group each include two voltage source converter valves or three voltage source converter valves.
Optionally, the two voltage source converter valves are respectively connected to any two input phases of the ac power supply, or the three voltage source converter valves are respectively connected to three input phases of the ac power supply.
Optionally, each voltage source converter valve includes an inductor and at least one single-phase full-bridge converter;
the inductor is connected with the single-phase full-bridge converter in series.
Optionally, the single-phase full-bridge converter includes a preset fully-controlled device and a capacitor device.
Optionally, the output ends of the first phase ice melting circuit, the second phase ice melting circuit and the third phase ice melting circuit are in short circuit in pairs through short circuit switches.
According to the technical scheme, the embodiment of the application has the following advantages:
in this application, a variable-frequency controllable current source ice melting device is provided, including: a voltage source type converter valve and an isolation knife switch; the voltage source type converter valve comprises a first voltage source type converter valve group, a second voltage source type converter valve group and a third voltage source type converter valve group; the input end of the first voltage source type converter valve group is connected with the input end of the alternating current power supply, and the output end of the first voltage source type converter valve group is connected with the first phase ice melting circuit; the input end of the second voltage source type converter valve group is connected with the input end of the alternating current power supply, and the output end of the second voltage source type converter valve group is connected with the second phase ice melting circuit; the input end of the third voltage source type converter valve group is connected with the input end of the alternating current power supply, and the output end of the third voltage source type converter valve group is connected with the third phase ice melting circuit; the isolation knife switch is arranged on the first phase ice melting circuit, the second phase ice melting circuit and the third phase ice melting circuit and used for controlling the on-off of the circuits.
According to the variable-frequency controllable current source ice melting device, the voltage source type converter valve groups are arranged on the three-phase circuit, different voltage source type converter valve groups are distributed on different single-phase ice melting circuits, and the on-off control is performed in the circuits by adopting the isolation disconnecting link, so that the ice melting of the three-phase circuit can be simultaneously realized by one-time control operation; the circuit structure is simple, ice melting can be realized on different wires according to adjustment of the isolation switch, the universality is strong, and the circuit can be applied to the ice melting of the wires under various scenes; the isolation switch is easy to operate. Therefore, the technical problems that the controllability is poor, the application occasions are limited and the ice melting efficiency is low in the conventional ice melting technology can be solved.
Drawings
Fig. 1 is a schematic structural diagram of a variable-frequency controllable current source ice melting device provided in an embodiment of the present application;
fig. 2 is a schematic diagram of an operation loop of a ground wire ice melting process provided in the embodiment of the present application;
fig. 3 is a schematic structural diagram of a static synchronous compensation circuit according to an embodiment of the present application;
fig. 4 is a circuit topology structure diagram of another variable-frequency controllable current source ice melting device provided in the embodiment of the present application;
FIG. 5 is a schematic diagram of an operation loop of a ground wire deicing process of another variable-frequency controllable current source deicing device according to the embodiment of the present application;
fig. 6 is a circuit structure diagram of another variable-frequency controllable current source ice melting device as a static synchronous compensation device according to an embodiment of the present application;
fig. 7 is a circuit topology structure diagram of a third variable-frequency controllable current source ice melting device provided in the embodiment of the present application;
fig. 8 is a schematic diagram of an operation loop of a ground wire deicing process of a third variable-frequency controllable current source deicing device according to the embodiment of the present application;
fig. 9 is a circuit structure diagram of a third variable-frequency controllable current source ice melting device as a static synchronous compensation device according to the embodiment of the present application;
fig. 10 is a schematic circuit diagram of a single fully-controlled device according to an embodiment of the present disclosure;
fig. 11 is a schematic circuit diagram of a parallel connection of dual fully-controlled devices according to an embodiment of the present disclosure;
fig. 12 is a schematic circuit diagram of a parallel connection of multiple fully-controlled devices according to an embodiment of the present disclosure;
fig. 13 is a schematic diagram of a loop in which an ice melting device melts ice on an overhead ground wire or an optical fiber composite ground wire (OPGW) when a voltage source converter valve group provided in the embodiment of the present application includes two voltage source converter valves;
fig. 14 is a schematic diagram of a loop in which an ice melting device melts ice on an overhead ground wire or an optical fiber composite ground wire (OPGW) when a voltage source converter valve group provided in the embodiment of the present application includes three voltage source converter valves;
reference numerals:
1. a first voltage source type converter valve group; 2. a second voltage source type converter valve group; 3. and a third voltage source type converter valve group.
Detailed Description
In order to make the technical solutions of the present application better understood, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
In the description of the embodiments of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the embodiments of the present application and simplifying the description, but do not indicate or imply that the referred devices or elements must have specific orientations, be configured in specific orientations, and operate, and thus, should not be construed as limiting the embodiments of the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the embodiments of the present application, it should be noted that the terms "mounted," "connected," and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected unless explicitly stated or limited otherwise; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. Specific meanings of the above terms in the embodiments of the present application can be understood in specific cases by those of ordinary skill in the art.
The existing power grid controllable ice melting device has the operation characteristic of a controllable direct current source, at least two steps of operations are needed for melting ice on three-phase wires of an alternating current transmission line, the first step is to remove ice on two-phase wires in a one-to-one phase mode, namely a wiring mode that the two-phase wires are connected in series to form a direct current loop; and the second step is to remove the ice coated on the other phase of the wire by adopting a 'relative two-phase' mode, namely, the two phases of the wire are connected in series with the third phase of the wire after the ice melting is finished to form a direct current loop connection mode. Obviously, the three-phase wire can be completed by two steps, and the efficiency is low. The variable-frequency controllable current source ice melting device provided by the application can simultaneously melt the ice of the three-phase electric wire by only one operation.
For easy understanding, please refer to fig. 1, an embodiment of a variable-frequency controllable current source ice melting apparatus provided in the present application includes: a voltage source type converter valve and an isolation knife switch;
the voltage source type converter valve comprises a first voltage source type converter valve group 1, a second voltage source type converter valve group 2 and a third voltage source type converter valve group 3; the three voltage source type converter valve groups have the same structure and specification.
The input end of the first voltage source type converter valve group 1 is connected with the input end of an alternating current power supply, and the output end of the first voltage source type converter valve group 1 is connected with the first phase ice melting circuit; the input end of the second voltage source type converter valve group 2 is connected with the input end of the alternating current power supply, and the output end of the second voltage source type converter valve group 2 is connected with the second phase ice melting circuit; the input end of the third voltage source type converter valve group 3 is connected with the input end of the alternating current power supply, and the output end of the third voltage source type converter valve group 3 is connected with the third phase ice melting circuit. Each single-phase ice melting circuit is distributed with a voltage source type converter valve group; the current frequency of the input phase of the alternating current power supply can be adjusted within the range of 0-50/3Hz, and the current adjustment is specifically executed according to the type and the practical application scene of the ice melting line. The AC power supply is connected through the 10KV or 35KV bus of the circuit board in the figure 1 and is controlled and connected by the isolation disconnecting links K1 and K2 and the breaker QF.
The isolation knife switch is arranged on the first phase ice melting circuit, the second phase ice melting circuit and the third phase ice melting circuit and used for controlling the on-off of the circuits. Different loops can be obtained by adjusting the isolation knife switch on the circuit, and the different loops are different functional circuits. For example, referring to fig. 2, as fig. 2 shows an ice melting loop, the corresponding isolation knife-switches on each phase of ice melting circuit are closed to turn on the three-phase circuit, so as to perform ice melting processing on the three-phase electric wire at the same time.
In addition, the ice melting device can be used for melting ice only in the icing period of each year, if the ice melting device can operate in a mode of a static synchronous compensation device in the non-icing period, the utilization rate of equipment can be obviously improved, the reactive power regulation and dynamic reactive power support capability of a transformer substation where the ice melting device is located can be improved, and the availability of the ice melting device in the icing period can be ensured. Therefore, the inside of the second voltage source type converter valve group 2 can be controlled by adding some isolation knife switches (such as Scw1, Scw2, Sbv1, Sbv2, Scv and Scu). For example, referring to fig. 1 and fig. 3, if the isolation knife switch Scv2 and the isolation knife switch Scu are closed, the loop shown in fig. 3 can be obtained, and the loop is not connected with the ice melting bus, so that the static synchronous compensation device is obtained.
When no isolation knife switch is added to the voltage source type converter valve group, a topological structure of the voltage source type converter valve group also exists, please refer to fig. 4, and a combined circuit formed by the voltage source type converter valve group is connected with the three-phase ice melting circuit through the isolation knife switches S1, S2 and S3. The ice melting process loop formed when switches S1, S2, and S3 were closed is shown in FIG. 5. When the switches S1, S2 and S3 are opened, a static synchronous compensator in a delta connection relationship can be formed, as shown in fig. 6.
According to the variable-frequency controllable current source ice melting device provided by the embodiment of the application, the voltage source type converter valve groups are arranged on the three-phase circuit, different voltage source type converter valve groups are distributed on different single-phase ice melting circuits, and the on-off control is performed in the circuits by adopting the isolation disconnecting links, so that the ice melting of the three-phase circuit can be simultaneously realized by one-time control operation; the circuit structure is simple, ice melting can be realized on different wires according to adjustment of the isolation switch, the universality is strong, and the circuit can be applied to the ice melting of the wires under various scenes; the isolation switch is easy to operate. Therefore, the technical problems that the existing ice melting technology is poor in controllability and limited in application occasions, and accordingly ice melting efficiency is low can be solved.
Further, the first voltage source converter valve group 1, the second voltage source converter valve group 2, and the third voltage source converter valve group 3 each include two voltage source converter valves or three voltage source converter valves.
Further, two voltage source type converter valves are respectively connected to any two input phases of the alternating current power supply, or three voltage source type converter valves are respectively connected to three input phases of the alternating current power supply.
It can be understood that, as shown in fig. 1, in the case that the voltage source converter valve group includes two voltage source converter valves (i.e., SM1 … SMn in fig. 1), optionally two ac power input phases are respectively connected to the two voltage source converter valves, two voltage source converter valves are connected in parallel to each single-phase ice melting circuit, an ice melting loop formed by on-off control through an isolation knife switch is shown in fig. 2, and a static synchronous compensation device is formed as shown in fig. 3.
If the voltage source type converter valve group comprises three voltage source type converter valves, please refer to fig. 7, each ac power input phase is connected in parallel with three voltage source type converter valves, and the line connected to the single-phase ice melting circuit comprises three voltage source type converter valves, the ice melting circuit formed by on-off control of the isolation knife-switch is shown in fig. 8, and the formed static synchronous compensation device is shown in fig. 9.
Further, each voltage source type converter valve comprises an inductor and at least one single-phase full-bridge converter; the inductor is connected in series with the single-phase full-bridge converter.
Further, the single-phase full-bridge current converter comprises a preset full-control type device and a capacitor device.
It should be noted that the inductor is installed at the input phase end of the near-ac power supply, and is connected in series with the single-phase full-bridge converter and then connected with the output phase to the single-phase ice melting circuit. Each pre-set fully controlled device includes an anti-parallel diode.
The preset fully-controlled device may adopt a single fully-controlled device, and the specific structure is shown in fig. 10; besides a single fully-controlled device, a dual fully-controlled device can be connected in parallel, and the specific structure is shown in fig. 11; in addition, a plurality of fully-controlled devices can be connected in parallel, and the specific structure is shown in fig. 12.
Further, the output ends of the first phase ice melting circuit, the second phase ice melting circuit and the third phase ice melting circuit are in short circuit in pairs through short circuit switches.
Referring to fig. 1 and 7, the output ends of the three single-phase ice melting circuits are short-circuited through the isolation knife-switch, specifically, the lines where Sab and Sbc are located are short-circuited at the tail end of the three-phase wire, and when the wire is subjected to ice melting operation, the short-circuit lines where Sg1 and Sg2 are located are in a disconnected state, so that the three-phase ice melting circuits are connected to form a wire ice melting loop; when the overhead ground wire and the optical fiber composite ground wire (OPGW) need to be de-iced, the Sg1 and the Sg2 are closed, and the Sab and the Sbc are opened. Referring to fig. 13 and 14, fig. 13 is a schematic diagram of a loop in which an ice melting device melts ice on an overhead ground wire or an optical fiber composite ground wire (OPGW) when a voltage source converter valve group includes two voltage source converter valves; fig. 14 is a schematic diagram of a loop in which the ice melting device melts ice on an overhead ground wire or an optical fiber composite ground wire (OPGW) when the voltage source converter valve group includes three voltage source converter valves.
It can be found that the ice melting device provided by the embodiment of the application can meet the ice melting requirements of various different power transmission and distribution lines, can better ensure the power quality in the operating condition, and hardly has influence on the alternating current system. The preset full-control device is utilized to meet the requirement of large variation range of current for deicing the ground wires, so that the deicing device can be used for deicing various ground wires.
The above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.
Claims (6)
1. A variable-frequency controllable current source ice melting device is characterized by comprising: a voltage source type converter valve and an isolation knife switch;
the voltage source type converter valve comprises a first voltage source type converter valve group, a second voltage source type converter valve group and a third voltage source type converter valve group;
the input end of the first voltage source type converter valve group is connected with the input end of an alternating current power supply, and the output end of the first voltage source type converter valve group is connected with the first phase ice melting circuit;
the input end of the second voltage source type converter valve group is connected with the input end of the alternating current power supply, and the output end of the second voltage source type converter valve group is connected with the second phase ice melting circuit;
the input end of the third voltage source type converter valve group is connected with the input end of the alternating current power supply, and the output end of the third voltage source type converter valve group is connected with the third phase ice melting circuit;
the isolation knife switch is arranged on the first-phase ice melting circuit, the second-phase ice melting circuit and the third-phase ice melting circuit and used for controlling the on-off of the circuits.
2. The variable-frequency controllable current source ice melting device according to claim 1, wherein the first voltage source converter valve group, the second voltage source converter valve group and the third voltage source converter valve group each include two voltage source converter valves or three voltage source converter valves.
3. The variable-frequency controllable current source ice melting device according to claim 2, wherein the two voltage source type converter valves are respectively connected to any two input phases of the alternating current power supply, or the three voltage source type converter valves are respectively connected to three input phases of the alternating current power supply.
4. The variable-frequency controllable current source ice melting device according to claim 2, wherein each voltage source converter valve comprises an inductor and at least one single-phase full bridge converter;
the inductor is connected with the single-phase full-bridge converter in series.
5. The variable frequency controllable current source ice melting apparatus according to claim 4, wherein said single phase full bridge inverter comprises a preset fully controlled device and a capacitor device.
6. The variable-frequency controllable current source ice melting device according to claim 1, wherein the output ends of the first phase ice melting circuit, the second phase ice melting circuit and the third phase ice melting circuit are shorted in pairs by a short-circuit knife switch.
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| CN202121033766.1U CN214590490U (en) | 2021-05-14 | 2021-05-14 | Variable-frequency controllable current source ice melting device |
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| CN202121033766.1U CN214590490U (en) | 2021-05-14 | 2021-05-14 | Variable-frequency controllable current source ice melting device |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113131428A (en) * | 2021-05-14 | 2021-07-16 | 南方电网科学研究院有限责任公司 | Variable-frequency controllable current source ice melting device |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113131428A (en) * | 2021-05-14 | 2021-07-16 | 南方电网科学研究院有限责任公司 | Variable-frequency controllable current source ice melting device |
| WO2022237023A1 (en) * | 2021-05-14 | 2022-11-17 | 南方电网科学研究院有限责任公司 | Variable-frequency controllable current source ice melting apparatus |
| CN113131428B (en) * | 2021-05-14 | 2023-02-28 | 南方电网科学研究院有限责任公司 | Variable-frequency controllable current source ice melting device |
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