CN111769478B - Direct-current ice melting control method for power transmission line - Google Patents

Direct-current ice melting control method for power transmission line Download PDF

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Publication number
CN111769478B
CN111769478B CN202010670974.6A CN202010670974A CN111769478B CN 111769478 B CN111769478 B CN 111769478B CN 202010670974 A CN202010670974 A CN 202010670974A CN 111769478 B CN111769478 B CN 111769478B
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ice melting
direct
current
line
ice
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CN111769478A (en
Inventor
班国邦
马晓红
谢百明
文屹
曾华荣
杨旗
张露松
杨柳青
李欣
陈沛龙
毛先胤
黄欢
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Guizhou Power Grid Co Ltd
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Guizhou Power Grid Co Ltd
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
    • H02G1/00—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines
    • H02G1/02—Methods or apparatus specially adapted for installing, maintaining, repairing or dismantling electric cables or lines for overhead lines or cables
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02G—INSTALLATION OF ELECTRIC CABLES OR LINES, OR OF COMBINED OPTICAL AND ELECTRIC CABLES OR LINES
    • H02G7/00—Overhead installations of electric lines or cables
    • H02G7/16—Devices for removing snow or ice from lines or cables
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00—Circuit arrangements for ac mains or ac distribution networks
    • H02J3/36—Arrangements for transfer of electric power between ac networks via a high-tension dc link
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/60—Arrangements for transfer of electric power between AC networks or generators via a high voltage DC link [HVCD]

Abstract

The invention discloses a direct-current ice melting control method for a power transmission line, which comprises the following steps: collecting operating parameters of a direct current ice melting device based on an MMC current converter; when a system starting instruction is received, starting and unlocking the direct current ice melting device according to the running parameters and a fixed direct current voltage control mode; obtaining ice melting operation parameters; according to the obtained ice melting operation parameters, automatically melting ice according to the ice melting time preset by the lines to be melted and each line; after all lines melt ice, the direct current ice melting device automatically switches to the SATACOM mode to operate; the direct-current ice melting device solves the technical problems that in the prior art, the operation condition of the direct-current ice melting device based on the MMC current converter is changed quickly, the difficulty of manual operation is increased, particularly when a plurality of power transmission lines need ice melting operation, a large amount of equipment starting, stopping, mode conversion and other operations need to be concentrated, the operation intensity of operators is high, the efficiency is low, and the like.

Description

Direct-current ice melting control method for power transmission line
Technical Field
The invention belongs to the technical field of ice melting of power transmission lines, and particularly relates to a direct-current ice melting control method for a power transmission line.
Background
In low-temperature rain and snow weather, the damage to the power transmission line is serious, and power grid facilities are seriously damaged, even the power grid is paralyzed. The direct-current ice melting device based on the MMC current converter conducts a certain current to a transmission line, and ice can be melted by icing when the heat generated by the direct current of the line is greater than the sum of the heat dissipation capacity of a wire and the ice melting heat, so that the capability of a power grid for resisting the natural ice and snow disasters is improved, and the safe and stable operation of the power grid is guaranteed.
The ice melting device is used for melting ice on the power transmission and distribution line in the ice coating period in winter, and the function reuse is realized in other time, so that the operation reliability of the transformer substation is improved. Flexible interconnection application technique between the main change based on MMC transverter improves the equipment utilization ratio that the transformer substation becomes, including realizing dynamic reactive compensation technique etc. realizes transformer substation alternating side bus voltage dynamic control and synthesizes electric energy quality and administer.
The direct-current ice melting device based on the MMC current converter is the most used equipment for the current power transmission lines, but the operation condition of the direct-current ice melting device based on the MMC current converter is changed quickly, the difficulty of manual operation is increased, particularly when a plurality of power transmission lines need ice melting operation, a large amount of equipment is centralized to start, stop, mode conversion and other operations, and the operation intensity of operators is high and the efficiency is low.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the method is used for solving the technical problems that in the prior art, the operation condition of a direct-current ice melting device based on an MMC current converter is changed quickly, the difficulty of manual operation is increased, particularly when a plurality of power transmission lines need ice melting operation, a large amount of equipment starting, stopping, mode conversion and other operations need to be concentrated, the operation intensity of operators is high, the efficiency is low and the like.
The technical scheme of the invention is as follows:
a DC ice melting control method for a power transmission line comprises the following steps:
step 1, collecting operating parameters of a direct current ice melting device based on an MMC current converter; using the operating parameters of the direct-current ice melting device to indicate the direct-current voltage, the active power target value and the reactive power target value of the direct-current ice melting device after starting;
step 2, when a system starting instruction is received, starting and unlocking the direct current ice melting device according to the running parameters and a fixed direct current voltage control mode;
step 3, obtaining ice melting operation parameters, wherein the ice melting operation parameters are used for indicating an ice melting target line, an ice melting time of each phase and an ice melting current target value of the direct current ice melting device;
step 4, automatically melting ice according to the obtained ice melting operation parameters and the ice melting time preset by the lines to be melted and each line;
and 5, automatically switching the direct-current deicing device to the STATCOM mode to operate after all lines are deicing.
The operating parameters of the direct-current ice melting device in the step 1 are shown in a table 1:
TABLE 1
Serial number Parameter name Description of parameters
1 Ud_ref Target value of DC voltage
2 Iac_ref Reactive current target value
3 Q_ref Target value of reactive power
4 Uac_ref Target value of AC voltage
5 cosΦ_ref Target value of power factor
The operating parameters of the direct-current deicing device are necessary parameters for unlocking operation or operation in a STATCOM mode of the direct-current deicing device.
The method for starting and unlocking the direct-current ice melting device according to the fixed direct-current voltage control mode comprises the following steps:
transition from grounded to shut down: the grounding switch is manually operated by an operator and is not in the electric operation control range, so that the initial state of the target direct-current ice melting device is the shutdown state, and the state conversion between grounding and shutdown is not involved;
transition from off-stream to standby: the target direct-current ice melting device checks whether the valve cooling system is started, and if the valve cooling system is started, the connecting secondary side isolation knife switch is closed, so that the process of converting from the outage state to the standby state is realized;
transition from standby to latched: when the target direct-current deicing device checks that the direct-current system configuration and the valve cooling system meet the locking condition, the variable incoming line breaker is connected in a closed mode; when the charging is checked, the starting resistance bypass switch is closed, so that the process of converting from the standby state to the locking state is realized;
transition from the locked state to the unlocked state: and when the target direct-current ice melting device detects that the direct-current system configuration meets the unlocking condition, the direct-current voltage is raised, so that the process of converting from the locking state to the unlocking state is realized.
And the state of the target direct current ice melting device is obtained by comprehensively judging the position of the breaker or the knife separator.
The ice melting operating parameters are shown in table 2:
TABLE 2
Figure GDA0003046252710000031
Figure GDA0003046252710000041
The ice melting operation parameters are necessary parameters in the ice melting process and are used for selecting ice melting lines, ice melting time of each line and a current target value during ice melting.
And 4, according to the obtained ice melting operation parameters, when ice melting is automatically started according to the ice melting time preset by the lines to be melted and each line, switching on and off corresponding phase selection switches according to different ice melting lines in the ice melting process, switching on and off the phase selection switches according to the states of the phase selection switches corresponding to the ice melting lines, automatically dividing all the phase selection switches after ice melting of each line is finished, and switching the control modes.
The ice melting process specifically comprises the following steps:
step 4.1, according to the selected line, after combining the phase selection knife switch corresponding to the first line to be fused, automatically switching the control mode, namely switching the control mode from a direct current control voltage to a direct current control mode, and leading the line to be fused to carry out ice melting on the line by leading target direct current;
step 4.2, when the time of melting ice is up, automatically switching the control mode, namely switching the control mode from direct current control to direct current voltage control, and then dividing all phase selection switches;
step 4.3, according to the selected line, according to a second line to be fused, after a corresponding phase selection knife switch of the second line to be fused is closed, automatically switching a control mode, namely switching the control mode from a direct current control voltage to a direct current control mode, and leading the line to be fused to carry out line de-icing by leading a target direct current;
step 4.4, when the time of melting ice is up, automatically switching the control mode, namely switching the control mode from the direct current control mode to the direct current voltage control mode, and then dividing all the phase selection switches;
and 4.5, completing the ice melting of all the lines in sequence.
And the operating parameters of the direct-current ice melting device and the ice melting operating parameters are issued by substation operators through a monitoring system.
The invention has the beneficial effects that:
the method comprises the following steps: acquiring an operation parameter; when a system starting instruction is received, starting the direct-current ice melting device according to the operation parameters; obtaining ice melting parameters; automatically completing an ice melting task according to the ice melting parameters after the starting is completed; and when the ice melting is finished, the direct-current ice melting device automatically changes to the STATCOM mode to operate. According to the invention, the automatic control of the direct-current ice melting device based on the MMC current converter is realized through the one-key system starting instruction, so that the manual intervention operation is greatly reduced, and the safe and stable operation of the direct-current ice melting device is ensured; the direct-current ice melting device solves the technical problems that in the prior art, the operation condition of the direct-current ice melting device based on the MMC current converter is changed quickly, the difficulty of manual operation is increased, particularly when a plurality of power transmission lines need ice melting operation, a large amount of equipment starting, stopping, mode conversion and other operations need to be concentrated, the operation intensity of operators is high, the efficiency is low, and the like.
Drawings
FIG. 1 is a schematic flow diagram of the present invention;
FIG. 2 is a flowchart illustrating the start-up of an embodiment of the present invention;
fig. 3 is a topology diagram of a line selection option of the dc transmission line in the embodiment of the present invention.
Detailed Description
The technical solution of the present invention is further explained below with reference to the drawings attached to the specification.
The invention provides a novel control method, which aims to solve the technical problems that the operation condition of a direct-current ice melting device based on an MMC current converter is changed quickly, the difficulty of manual operation is increased, particularly when a plurality of power transmission lines need ice melting operation, a large amount of operations such as equipment starting, stopping, mode conversion and the like are concentrated, the operation intensity of an operator is high and the like, and the whole ice melting process is automatically completed after starting, and the method comprises the following steps:
(1) obtaining DC ice melting device operation parameter based on MMC transverter
Table 1: operating parameters of DC ice melting device
Serial number Parameter name Description of parameters
1 Ud_ref Target value of DC voltage
2 Iac_ref Reactive current target value
3 Q_ref Target value of reactive power
4 Uac_ref Target value of AC voltage
5 cosΦ_ref Target value of power factor
The operation parameters of the DC ice melting device of the MMC current converter are necessary parameters for unlocking operation or operation in a STATCOM mode, and are issued by a monitoring system by substation operators.
(2) Unlocking the DC ice melting device of the MMC converter, as shown in figure 2
And when a system starting instruction is received, starting and unlocking the direct-current ice melting device according to the running parameters in a fixed direct-current voltage control mode. The method comprises the following steps:
the state transition method of the target dc-ice melting apparatus will be described. The state of the target direct current ice melting device is comprehensively judged according to the position of the breaker or the knife.
1) Transition from grounded to shut down: the grounding switch is generally operated manually by an operator and is not in an electric operation control range, so that the initial state of the target direct-current ice melting device is a shutdown state, and state conversion between grounding and shutdown is not involved.
2) Transition from off-stream to standby: and the target direct-current ice melting device checks whether the valve cooling system is started or not, and if the valve cooling system is started, the connecting secondary side isolation knife switch is switched on, so that the process of converting the shutdown state into the standby state is realized.
3) Transition from standby to latched: and when the target direct-current deicing device checks that the direct-current system configuration and the valve cooling system meet the locking condition, the variable incoming line breaker is connected. When the charging is checked to be completed, the starting resistance bypass switch is closed, so that the process of converting from the standby state to the locking state is realized.
4) Transition from the locked state to the unlocked state: and when the target direct-current ice melting device detects that the direct-current system configuration meets the unlocking condition, the direct-current voltage is raised, so that the process of converting from the locking state to the unlocking state is realized.
(3) Obtaining parameters required for the ice melting process, as shown in attached Table 2
Table 2: ice melting parameter of DC ice melting device
Figure GDA0003046252710000071
The ice melting parameters of the direct-current ice melting device of the MMC current converter are necessary parameters in the ice melting process, are used for selecting ice melting lines, ice melting time of each line and a current target value during ice melting, and are issued by a monitoring system by substation operators.
(4) Automatically melting ice according to the obtained ice melting parameters
According to the power transmission line topology shown in fig. 3 as an example, the corresponding phase selection switches are switched on and off according to different ice melting circuits in the ice melting process, the states of the phase selection switches corresponding to the ice melting circuits are shown in table 3, the phase selection switches are automatically divided into phases after ice melting of each circuit is finished, and the control mode is switched. The method comprises the following steps:
table 3: pending line option switch state
Ice melting line Switch 1 Switch 2 Switch 3 Switch 4 Switch 5 Switch 6
A-B Combination of Chinese herbs Is divided into Is divided into Is divided into Combination of Chinese herbs Is divided into
A-C Combination of Chinese herbs Is divided into Is divided into Is divided into Is divided into Combination of Chinese herbs
B-C Is divided into Combination of Chinese herbs Is divided into Is divided into Is divided into Combination of Chinese herbs
A-BC Combination of Chinese herbs Is divided into Is divided into Is divided into Combination of Chinese herbs Combination of Chinese herbs
B-AC Is divided into Combination of Chinese herbs Is divided into Combination of Chinese herbs Is divided into Combination of Chinese herbs
C-AB Is divided into Is divided into Combination of Chinese herbs Combination of Chinese herbs Combination of Chinese herbs Is divided into
1) And according to the selected line, after a phase selection knife switch corresponding to the first line to be melted is closed, automatically switching the control mode, namely switching the control mode from a direct current control voltage to a direct current control mode, and introducing a target direct current to the line to be melted for melting the ice of the line.
2) When the time of the ice melting line is up, the control mode is automatically switched, namely the control mode is switched from the direct current control mode to the direct current voltage control mode, and then all the phase selection switches are switched.
3) And according to the selected line, according to the second line to be melted, after a corresponding phase selection knife switch of the second line to be melted is closed, automatically switching the control mode, namely switching the control mode from the direct current control voltage to the direct current control mode, and introducing the target direct current to the line to be melted for melting the ice of the line.
4) When the time of the ice melting line is up, the control mode is automatically switched, namely the control mode is switched from the direct current control mode to the direct current voltage control mode, and then all the phase selection switches are switched.
5) And thus, melting ice of all lines is completed.
(5) And after all lines are de-iced, the direct current de-icing device automatically changes to the STATCOM mode to operate.

Claims (8)

1. A DC ice melting control method for a power transmission line comprises the following steps:
step 1, collecting operating parameters of a direct current ice melting device based on an MMC current converter; using the operating parameters of the direct-current ice melting device to indicate the direct-current voltage, the active power target value and the reactive power target value of the direct-current ice melting device after starting;
step 2, when a system starting instruction is received, starting and unlocking the direct current ice melting device according to the running parameters and a fixed direct current voltage control mode;
step 3, obtaining ice melting operation parameters, wherein the ice melting operation parameters are used for indicating an ice melting target line, an ice melting time of each phase and an ice melting current target value of the direct current ice melting device;
step 4, automatically melting ice according to the obtained ice melting operation parameters and the ice melting time preset by the lines to be melted and each line;
and 5, automatically switching the direct-current deicing device to the STATCOM mode to operate after all lines are deicing.
2. The direct-current deicing control method for the power transmission line according to claim 1, characterized in that: the operating parameters of the direct-current ice melting device in the step 1 are shown in a table 1:
TABLE 1
Serial number Parameter name Description of parameters 1 Ud_ref Target value of DC voltage 2 Iac_ref Reactive current target value 3 Q_ref Target value of reactive power 4 Uac_ref Target value of AC voltage 5 cosΦ_ref Target value of power factor
The operating parameters of the direct-current deicing device are necessary parameters for unlocking operation or operation in a STATCOM mode of the direct-current deicing device.
3. The direct-current deicing control method for the power transmission line according to claim 1, characterized in that: the method for starting and unlocking the direct-current ice melting device according to the fixed direct-current voltage control mode comprises the following steps:
transition from grounded to shut down: the grounding switch is manually operated by an operator and is not in the electric operation control range, so that the initial state of the target direct-current ice melting device is the shutdown state, and the state conversion between grounding and shutdown is not involved;
transition from off-stream to standby: the target direct-current ice melting device checks whether the valve cooling system is started, and if the valve cooling system is started, the connecting secondary side isolation knife switch is closed, so that the process of converting from the outage state to the standby state is realized;
transition from standby to latched: when the target direct-current deicing device checks that the direct-current system configuration and the valve cooling system meet the locking condition, the variable incoming line breaker is connected in a closed mode; when the charging is checked, the starting resistance bypass switch is closed, so that the process of converting from the standby state to the locking state is realized;
transition from the locked state to the unlocked state: and when the target direct-current ice melting device detects that the direct-current system configuration meets the unlocking condition, the direct-current voltage is raised, so that the process of converting from the locking state to the unlocking state is realized.
4. The direct-current deicing control method for the power transmission line according to claim 3, characterized in that: and the state of the target direct current ice melting device is obtained by comprehensively judging the position of the breaker or the knife separator.
5. The direct-current deicing control method for the power transmission line according to claim 1, characterized in that: the ice melting operating parameters are shown in table 2:
TABLE 2
Figure FDA0003046252700000021
Figure FDA0003046252700000031
The ice melting operation parameters are necessary parameters in the ice melting process and are used for selecting ice melting lines, ice melting time of each line and a current target value during ice melting.
6. The direct-current deicing control method for the power transmission line according to claim 1, characterized in that: and 4, according to the obtained ice melting operation parameters, when ice melting is automatically started according to the ice melting time preset by the lines to be melted and each line, switching on and off corresponding phase selection switches according to different ice melting lines in the ice melting process, switching on and off the phase selection switches according to the states of the phase selection switches corresponding to the ice melting lines, automatically dividing all the phase selection switches after ice melting of each line is finished, and switching the control modes.
7. The direct-current deicing control method of the power transmission line according to claim 6, characterized in that: the ice melting process specifically comprises the following steps:
step 4.1, according to the selected line, after combining the phase selection knife switch corresponding to the first line to be fused, automatically switching the control mode, namely switching the control mode from a direct current control voltage to a direct current control mode, and leading the line to be fused to carry out ice melting on the line by leading target direct current;
step 4.2, when the time of melting ice is up, automatically switching the control mode, namely switching the control mode from direct current control to direct current voltage control, and then dividing all phase selection switches;
step 4.3, according to the selected line, according to a second line to be fused, after a corresponding phase selection knife switch of the second line to be fused is closed, automatically switching a control mode, namely switching the control mode from a direct current control voltage to a direct current control mode, and leading the line to be fused to carry out line de-icing by leading a target direct current;
step 4.4, when the time of melting ice is up, automatically switching the control mode, namely switching the control mode from the direct current control mode to the direct current voltage control mode, and then dividing all the phase selection switches;
and 4.5, completing the ice melting of all the lines in sequence.
8. The direct-current deicing control method for the power transmission line according to claim 1, characterized in that: and the operating parameters of the direct-current ice melting device and the ice melting operating parameters are issued by substation operators through a monitoring system.
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CN103280757A (en) * 2013-06-20 2013-09-04 国家电网公司 Direct-current deicing output electric switching device
CN106300200A (en) * 2015-05-29 2017-01-04 国家电网公司 A kind of removable DC de-icing device having STATCOM function concurrently and de-icing method thereof
RU2621068C1 (en) * 2016-07-06 2017-05-31 Акционерное общество "Научно-технический центр Федеральной сетевой компании Единой энергетической системы" Reactive power compensation and ice-melting combination device on the basis of the driven shunt reactor transformer
CN107248720B (en) * 2017-08-16 2023-06-27 国网湖南省电力公司 Intensive direct-current ice melting device with waste heat power generation function and control method thereof
CN110165697B (en) * 2019-06-06 2021-04-30 北京四方继保自动化股份有限公司 One-key starting and stopping method and device for multi-terminal flexible direct current power distribution system
CN110880709B (en) * 2019-10-23 2020-10-16 贵州电网有限责任公司 Method for determining ice-watching dispatching time of power transmission line

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