CN107453383B - Flexible direct current configuration method and device for power supply partition interconnection - Google Patents
Flexible direct current configuration method and device for power supply partition interconnection Download PDFInfo
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- 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
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
- H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
- H02H7/261—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations
- H02H7/263—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured involving signal transmission between at least two stations involving transmissions of measured values
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
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- H02H7/268—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured for dc systems
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
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Abstract
The invention relates to a flexible direct current configuration method and a flexible direct current configuration device for power supply partition interconnection, wherein the method comprises the following steps: determining a flexible direct current transmitting and receiving end power grid according to the power grid power supply margin of the power supply subarea; determining upper and lower limits of flexible direct current rated power, and determining a flexible direct current rated power limiting condition by using the upper and lower limits of the flexible direct current rated power; respectively determining flexible direct current drop point buses of a flexible direct current transmission and receiving end power grid; after the flexible direct current is connected to the grid, safety and stability check are carried out on the flexible direct current transmission and receiving end power grid; according to the technical scheme provided by the invention, the two power supply subareas are connected through the flexible direct current, so that an electromagnetic looped network can be prevented from being generated, the exceeding of short-circuit current is inhibited, and meanwhile, when a certain subarea breaks down, active and reactive power support can be provided through the flexible direct current power control, and the support of the other subarea on the fault subarea is realized.
Description
Technical Field
The invention relates to the field of power supply partitions, in particular to a flexible direct current configuration method and device for power supply partition interconnection.
Background
With the development of a power grid, under the condition that a power system does not meet the reliability of power supply or is not strong enough in a high-level voltage network, in order to reasonably utilize the existing resources to guarantee the power transmission capacity and meet the requirements of users on power utilization, a high-low voltage electromagnetic ring network is formed.
The electromagnetic ring network has the existing significance in the initial stage of building a new voltage class, and is beneficial to improving the power supply capacity of a system and reducing the standby capacity. With the development of a higher-voltage-level power grid and the continuous increase of transmission load, the electromagnetic ring network becomes a serious accident potential of a power system. For example, when the primary high voltage line is disconnected, the load on the primary high voltage line is substantially transferred to the primary low voltage line, and the power on the low voltage line may exceed its thermal stability limit.
The safety and stability of the power system stipulates that the next-stage voltage power grid gradually realizes that the adjacent subareas are communicated and mutually stand by with the construction of the higher-stage voltage power grid. The research and implementation work of the ring-opening of the electromagnetic ring network is carried out by a plurality of provincial network companies in China by combining the conditions of all regions.
Generally, the transformers are operated in a row mode or low-voltage buses of the transformers are operated in a section mode to form a low-voltage power supply partition, so that an electromagnetic ring network is looped, the short-circuit current level is controlled, and the overall power supply capacity is improved. However, this method has the following disadvantages:
(1) the power supply reliability of each subarea is reduced;
(2) when a problem occurs in a transformer placed under a certain subarea, the subarea loses a power supply point, and only other subareas supply power through a hot standby line, so that the load requirement cannot be met, and a large amount of load is lost;
(3) the electrical connection between the sub-areas is weakened and the voltage supporting capability is reduced.
The flexible direct current transmission technology is used as a new generation direct current transmission technology, can realize independent control of active power and reactive power, and does not need a reactive power compensation device. The flexible direct-current transmission technology is very suitable for scenes such as renewable energy source grid connection, urban power grid power supply and the like by combining technical characteristics and engineering practice of the flexible direct-current transmission technology.
Disclosure of Invention
The invention provides a flexible direct current configuration method and a flexible direct current configuration device for power supply partition interconnection, and aims to connect two power supply partitions through flexible direct current, avoid the generation of an electromagnetic looped network, inhibit the standard exceeding of short-circuit current, and provide active and reactive power support through flexible direct current power control when a certain partition breaks down, so as to realize the support of the other partition on a fault partition.
The purpose of the invention is realized by adopting the following technical scheme:
in a method of flexible dc configuration for interconnection of power supply partitions, the improvement comprising:
determining a flexible direct current transmitting and receiving end power grid according to the power grid power supply margin of the power supply subarea;
determining upper and lower limits of flexible direct current rated power, and determining a flexible direct current rated power limiting condition by using the upper and lower limits of the flexible direct current rated power;
respectively determining flexible direct current drop point buses of a flexible direct current transmission and receiving end power grid;
and after the flexible direct current is connected to the grid, performing safety and stability check on the flexible direct current transmission and receiving end power grid.
Preferably, the grid power supply margin η of the power supply partition is determined according to the following formula:
in the above formula, PTmaxFor all active power of the down-converter at maximum power supply capacity of the network, PT0For an electric networkActive power of all down-casting transformers in an initial state;
wherein, the active power P of all the downward-poured transformers when the maximum power supply capacity of the power grid is determined according to the following formulaTmax：
PTmax＝Pmax-Gmax
In the above formula, PmaxFor maximum power supply capacity of the grid, GmaxAnd all the corresponding power of the generator at the maximum power supply capacity of the power grid.
Preferably, the power supply section includes: a first power supply section and a second power supply section.
Further, the determining the flexible dc transmitting and receiving end power grid according to the power grid power supply margin of the power supply partition includes:
and taking the power supply subarea with large power supply margin of the power grid in the power supply subareas as a flexible direct-current transmitting-end power grid, and taking the power supply subarea with small power supply margin of the power grid as a flexible direct-current receiving-end power grid.
Preferably, the determining the upper and lower limits of the flexible dc rated power and determining the flexible dc rated power limiting condition by using the upper and lower limits of the flexible dc rated power include:
determining the lower limit P of the rated power of the flexible direct current according to the following formulaNmin：
PNmin＝Pr-max-Pr-max-N-1
In the above formula, Pr-maxThe maximum power receiving capacity P of a flexible direct current grid-connected front receiving end power gridr-max-N-1The maximum power receiving capacity is the maximum power receiving capacity of any lower-input transformer in a receiving-end power grid or any main power plant under the condition of loss;
determining the upper limit P of the rated power of the flexible direct current according to the following formulaNmax：
PNmax＝Psmax-Gs0-PTs0
In the above formula, PsmaxFor maximum power receiving capacity, G, of flexible DC grid-connected front-end power grids0Is the power of all generators of the sending end power grid in the initial state, PTs0All the power of the transformer is input to the power grid at the transmitting end in the initial state;
the soft DC rated power limit condition is PNmin≤PN≤PNmaxWherein P isNThe power is flexible DC rated power.
Preferably, the determining the flexible dc drop point buses of the flexible dc transmission and reception end power grid respectively includes:
after the flexible direct current is connected to a bus in a receiving-end power grid, if the power reduction amount of a power injection transformer which is fully loaded in the flexible direct current receiving-end power grid at first is the largest and the power supply capacity of the flexible direct current receiving-end power grid is the largest, selecting the bus as a flexible direct current drop point bus of the flexible direct current receiving-end power grid;
and selecting a bus which can bear the flexible direct current rated capacity and is closest to the power supply in the subarea as a flexible direct current drop point bus of the flexible direct current transmission end power grid.
Preferably, after the flexible direct current is connected to the grid, the safety and stability of the power grid at the transmission and reception end of the flexible direct current is checked, and the method includes:
and (3) performing safety and stability check on the flexible direct current transmitting and receiving end power grid by using the system N-1 fault and the flexible direct current single-stage and bipolar locking faults.
In a flexible dc configuration arrangement for interconnection of power supply bays, the improvement comprising:
the first determining unit is used for determining a flexible direct current transmitting and receiving end power grid according to the power grid power supply margin of the power supply partition;
the second determining unit is used for determining the upper limit and the lower limit of the flexible direct current rated power and determining the limiting condition of the flexible direct current rated power by utilizing the upper limit and the lower limit of the flexible direct current rated power;
the third determining unit is used for respectively determining flexible direct current drop point buses of the flexible direct current transmission and receiving end power grid;
and the checking unit is used for performing safety and stability checking on the flexible direct current transmission and receiving end power grid after the flexible direct current is connected to the grid.
Preferably, the grid power supply margin η of the power supply partition is determined according to the following formula:
in the above formula, PTmaxFor all active power of the down-converter at maximum power supply capacity of the network, PT0Active power of all the downward-fed transformers in the initial state of the power grid is obtained;
wherein, the active power P of all the downward-poured transformers when the maximum power supply capacity of the power grid is determined according to the following formulaTmax：
PTmax＝Pmax-Gmax
In the above formula, PmaxFor maximum power supply capacity of the grid, GmaxAnd all the corresponding power of the generator at the maximum power supply capacity of the power grid.
Preferably, the power supply section includes: a first power supply section and a second power supply section.
Further, the first determining unit includes:
the first determining module is used for taking the power supply subarea with large power supply margin of a power grid in the power supply subareas as a flexible direct-current sending-end power grid and taking the power supply subarea with small power supply margin of the power grid as a flexible direct-current receiving-end power grid.
Preferably, the second determination unit includes:
a second determining module for determining the lower limit P of the flexible DC rated power according to the following formulaNmin：
PNmin＝Pr-max-Pr-max-N-1
In the above formula, Pr-maxThe maximum power receiving capacity P of a flexible direct current grid-connected front receiving end power gridr-max-N-1The maximum power receiving capacity is the maximum power receiving capacity of any lower-input transformer in a receiving-end power grid or any main power plant under the condition of loss;
a third determining module for determining the upper limit P of the flexible DC rated power according to the following formulaNmax：
PNmax＝Psmax-Gs0-PTs0
In the above formula, PsmaxFor maximum power receiving capacity, G, of flexible DC grid-connected front-end power grids0Is sent end in initial statePower of all generators of the grid, PTs0All the power of the transformer is input to the power grid at the transmitting end in the initial state;
the soft DC rated power limit condition is PNmin≤PN≤PNmaxWherein P isNThe power is flexible DC rated power.
Preferably, the third determining unit includes:
the first selection module is used for selecting the bus as a flexible direct current landing bus of the flexible direct current receiving end power grid after the flexible direct current is connected to the bus in the receiving end power grid, if the power reduction amount of the power injection transformer which is fully loaded in the flexible direct current receiving end power grid at first is the largest and the power supply capacity of the flexible direct current receiving end power grid is the largest;
and the second selection module is used for selecting the bus which can bear the flexible direct current rated capacity and is closest to the power supply in the subarea in the collection channel as the flexible direct current drop point bus of the flexible direct current sending end power grid.
Preferably, the checking unit includes:
and the checking module is used for performing safety and stability checking on the flexible direct current transmitting and receiving end power grid by utilizing the system N-1 fault, the flexible direct current single-stage and bipolar latching fault.
The invention has the beneficial effects that:
according to the technical scheme provided by the invention, the power supply margin of the power supply subareas is utilized to determine the flexible direct current transmitting and receiving end power grid, the flexible direct current rated power limiting condition is determined by utilizing the upper limit and the lower limit of the flexible direct current rated power, meanwhile, the flexible direct current drop point bus of the flexible direct current transmitting and receiving end power grid is determined, the power transmission direction, the rated capacity and the transmitting and receiving end drop point of the flexible direct current are determined, the active power and reactive power supporting capability among the subareas can be improved, the generation of an electromagnetic looped network can be avoided, the short-circuit current is inhibited from exceeding the standard, and meanwhile, when a certain subarea fails, the active power and reactive power support can be provided through the flexible direct current power control, the support of the other subarea to the fault subarea.
Drawings
FIG. 1 is a flow chart of a method of flexible DC configuration for power supply zone interconnection of the present invention;
FIG. 2 is a schematic grid structure diagram of a BJ grid HC partition and a CC partition in the embodiment of the invention;
FIG. 3 is a schematic diagram of a grid structure of HC partitions and CC partitions after the flexible DC grid connection in the embodiment of the present invention;
fig. 4 is a schematic structural diagram of a flexible dc configuration device for interconnection of power supply sections according to the present invention.
Detailed Description
The following detailed description of embodiments of the invention refers to the accompanying drawings.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. 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 invention.
The existing power supply partitioning method of the power grid has the problems of low partitioning power supply reliability and insufficient support capability of active power and reactive power among partitions, the flexible direct current configuration method for power supply partitioning interconnection provided by the invention can avoid the generation of an electromagnetic looped network and inhibit the standard exceeding of short-circuit current by connecting two power supply partitions through flexible direct current, and meanwhile, when a certain partition breaks down, active power and reactive power support can be provided through flexible direct current power control to realize the support of the other partition on the fault partition, as shown in figure 1, the method comprises the following steps:
101. determining a flexible direct current transmitting and receiving end power grid according to the power grid power supply margin of the power supply subarea;
102. determining upper and lower limits of flexible direct current rated power, and determining a flexible direct current rated power limiting condition by using the upper and lower limits of the flexible direct current rated power;
103. respectively determining flexible direct current drop point buses of a flexible direct current transmission and receiving end power grid;
104. and after the flexible direct current is connected to the grid, performing safety and stability check on the flexible direct current transmission and receiving end power grid.
The power supply margin eta of the power supply subarea is determined according to the following formula:
in the above formula, PTmaxFor all active power of the down-converter at maximum power supply capacity of the network, PT0Active power of all the downward-fed transformers in the initial state of the power grid is obtained;
wherein, the active power P of all the downward-poured transformers when the maximum power supply capacity of the power grid is determined according to the following formulaTmax：
PTmax＝Pmax-Gmax
In the above formula, PmaxFor maximum power supply capacity of the grid, GmaxAnd all the corresponding power of the generator at the maximum power supply capacity of the power grid.
The power supply section includes: a first power supply section and a second power supply section.
According to the technical scheme provided by the invention, a flexible direct current receiving end power grid is selected between two power supply subareas, so that the step 101 comprises the following steps:
and taking the power supply subarea with large power supply margin of the power grid in the power supply subareas as a flexible direct-current transmitting-end power grid, and taking the power supply subarea with small power supply margin of the power grid as a flexible direct-current receiving-end power grid.
The step 102 includes:
determining the lower limit P of the rated power of the flexible direct current according to the following formulaNmin：
PNmin＝Pr-max-Pr-max-N-1
In the above formula, Pr-maxThe maximum power receiving capacity P of a flexible direct current grid-connected front receiving end power gridr-max-N-1The maximum power receiving capacity is the maximum power receiving capacity of any lower-input transformer in a receiving-end power grid or any main power plant under the condition of loss;
wherein, the maximum power receiving capacity P of the flexible direct current grid-connected front receiving end power gridr-maxAccording to constant load of receiving end power gridWhen the power factor is increased, the maximum power receiving capacity P under the condition that the load power of any transformer reaches the thermal stability limit and the total corresponding load is lost by any downward-feeding transformer in the receiving-end power grid or any main power plantr-max-N-1In the receiving-end power grid N-1 mode, when the load is increased according to the constant power factor, the minimum value of the total amount of the corresponding load when the load power of any transformer reaches the thermal stability limit is selected.
Determining the upper limit P of the rated power of the flexible direct current according to the following formulaNmax：
PNmax＝Psmax-Gs0-PTs0
In the above formula, PsmaxFor maximum power receiving capacity, G, of flexible DC grid-connected front-end power grids0Is the power of all generators of the sending end power grid in the initial state, PTs0All the power of the transformer is input to the power grid at the transmitting end in the initial state;
wherein, the maximum receiving capacity P of the flexible direct current grid-connected front end power gridsmaxWhen the load of the power grid at the sending end is increased according to the constant power factor, the total load amount corresponding to the condition that the load power of any transformer reaches the thermal stability limit is obtained;
the soft DC rated power limit condition is PNmin≤PN≤PNmaxWherein P isNThe power is flexible DC rated power.
The step 103 includes:
after the flexible direct current is connected to a bus in a receiving-end power grid, if the power reduction amount of a power injection transformer which is fully loaded in the flexible direct current receiving-end power grid at first is the largest and the power supply capacity of the flexible direct current receiving-end power grid is the largest, selecting the bus as a flexible direct current drop point bus of the flexible direct current receiving-end power grid;
and selecting a bus which can bear the flexible direct current rated capacity and is closest to the power supply in the subarea as a flexible direct current drop point bus of the flexible direct current transmission end power grid.
The step 4 comprises the following steps:
and (3) performing safety and stability check on the flexible direct current transmitting and receiving end power grid by using the system N-1 fault and the flexible direct current single-stage and bipolar locking faults.
The invention provides an embodiment of a flexible direct current configuration method for power supply partition interconnection, which comprises the steps of analyzing and calculating a BJ power grid and providing a configuration scheme of applying a flexible direct current interconnection BJ220kV power supply partition, wherein grid structures of a BJ power grid HC partition and a CC partition are shown in figure 2, the CC partition is provided with three 500kV/220kV power injection transformers which are respectively CP1, CP2 and CB2, and rated powers are respectively 800MW, 800MW and 1200 MW; the HC subarea is provided with two 500kV/220kV power down-feeding transformers which are respectively HD2 and CP3, and the rated power is 1200 MW.
Step 1: and selecting a flexible direct current transmission and receiving end power grid.
The power supply margins of the CC partition and the HC partition are calculated, respectively.
Aiming at CC partition, the load is increased according to constant power factor, when the active load is increased to 3300MW, the main power of CP2 transformer reaches 800MW, and reaches the thermal stability limit, then Pmax-CC3300MW, at which time CC partitions all generator outputs Gmax-CC795MW, then PTmax-CCAt 2505MW, it was found from the initial trial that CP1, CP2 and CB2 were 252.1, 255.4 and 297.6MW, respectively, i.e., PT0-CCWhen 805MW, it can be known:
by the same token, for HC partition, Pmax-HCIs 3870MW, Gmax-HCIs 1875MW, PTmax-HC1995MW, PT0-HC950MW, then ηHC1.10, so the CC section is selected as the sending end of the interconnected flexible direct current and the HC section is selected as the receiving end of the interconnected flexible direct current.
Step 2: and selecting flexible direct current rated capacity.
(1) And determining the lower limit of the flexible direct-current rated power through the receiving-end power grid.
Step 1 shows that the maximum power receiving capacity P of a flexible direct current grid-connected front receiving end power grid HC partitionr-max3830 MW. The results of calculating the maximum power receiving capacity of the receiving-end power grid under different power-down transformer and main power plant loss conditions are shown in table 1:
TABLE 1 maximum receiving power of receiving-end network under different loss conditions of lower-side transformer and main power plant
| Serial number | N-1 element | Electric power (MW) |
| 1 | CP3 | 2855 |
| 2 | HD2 | 2860 |
| 3 | GJ plant 1 machine | 3560 |
| 4 | 1 machine of JN factory | 3585 |
Then P isr-max-N-12855MW, respectively, the lower limit of the rated power P of the flexible direct currentNmin975 MW.
(2) And determining the upper limit of the flexible direct current rated power through a sending end power grid.
According to the step 1, the maximum power receiving capacity P of the CC partition of the flexible direct current grid-connected front-end power grids-maxIs 3870MW, PTs0950MW, from tidal current results, Gs0Is 785MW, flexible DC ratedUpper limit of power PNmaxComprises the following steps:
PNmax＝Psmax-Gs0-PTs0
＝3870-785-950
＝2135
therefore, when power support is provided for other subareas, the safe power supply of the power grid of the subarea is not influenced.
3) The flexible direct current rated power P is combined with different requirements of a transmitting end power grid and a receiving end power gridNSatisfies the following conditions: 975 is less than or equal to PN2135 or less; determining the rated power P of the flexible direct current by combining the flexible direct current engineering practiceNIs 1000 MW.
And step 3: and selecting a drop point of the flexible direct current transmitting and receiving end.
(1) And calculating the improvement condition of the original receiving end power grid power supply capacity limit value condition after calculating different buses of the flexible direct current receiving end drop point. Flexible DC rated power PNFor 1000MW, a bus with a large load and a large number of evacuation channels should be selected as a receiving end drop point in view of both economy and safety. Primarily selecting XST, SZ and KYH buses, and calculating the improvement condition of the power supply capacity limit condition after flexible direct current is respectively connected into the buses, as shown in Table 2:
TABLE 2 improvement of power supply capacity limit conditions after flexible DC access to different buses
| Serial number | Drop point bus | CP2 Main Transformer Power this variable (MW) |
| 1 | XST | -584.3 |
| 2 | SZ | -522.8 |
| 3 | KYH | -497.7 |
(2) After calculating different buses of the flexible direct current receiving end drop point, the power supply capacity of a receiving end power grid is shown in a table 3:
TABLE 3 HC power supply capability after flexible DC access to different buses
| Serial number | Drop point bus | HC zone power supply capability (MW) |
| 1 | XST | 4970 |
| 2 | SZ | 4845 |
| 3 | KYH | 4755 |
(3) And (4) integrating the influences of different buses of the flexible direct current drop point on the power supply capacity and the limit value condition, and selecting the flexible direct current receiving end drop point. As can be seen from tables 2 and 3, the flexible dc drop point XST bus can reduce the main power input of the CP2 transformer to the maximum and improve the power supply capability of the HC partition to the maximum, so the XST bus is selected as the flexible dc receiving drop point.
(4) And determining a flexible direct current sending end drop point by combining the flexible direct current transmission power and the sending end grid structure. According to the step 2, the flexible direct current rated power PNFor 1000MW, bus nodes with more collecting channels should be selected to reduce the transport capacity of each channel from the safety aspect; in view of economy, a bus node closer to a power supply should be selected so as to directly supply surplus power to a receiving end load region through flexible direct current, thereby reducing loss. In view of the above two aspects, after the nodes of the bus at the sending end are screened by combining the grid structure at the sending end, the HJY bus is found to be closest to the power supply, and 3 collecting channels are provided, so that the HJY bus is most suitable to be used as a flexible direct current sending end bus.
And 4, step 4: and (4) safety and stability checking after the flexible direct current is connected to the grid.
The safety and stability check after the flexible direct current grid connection mainly comprises an alternating current system N-1 fault, a flexible direct current single-stage and bipolar locking fault, and the result is shown in a table 4:
TABLE 4 safety and stability checking results after N-1 fault of power-tolerant power-down transformer
| Serial number | Fault of | Results | |
| 1 | | System stabilization | |
| 2 | CP2 | System stabilization | |
| 3 | CP3 | System stabilization | |
| 4 | CB2 | System stabilization | |
| 5 | HD2 | System stabilization | |
| 6 | Flexible straight single-pole lock | System stabilization | |
| 7 | Flexible and straight bipolar lock | System stabilization |
The HC partition and CC partition grid structure after the flexible direct current grid connection is shown in fig. 3.
The present invention also provides a flexible dc configuration apparatus for interconnecting power supply partitions, as shown in fig. 4, the apparatus including:
the first determining unit is used for determining a flexible direct current transmitting and receiving end power grid according to the power grid power supply margin of the power supply partition;
the second determining unit is used for determining the upper limit and the lower limit of the flexible direct current rated power and determining the limiting condition of the flexible direct current rated power by utilizing the upper limit and the lower limit of the flexible direct current rated power;
the third determining unit is used for respectively determining flexible direct current drop point buses of the flexible direct current transmission and receiving end power grid;
and the checking unit is used for performing safety and stability checking on the flexible direct current transmission and receiving end power grid after the flexible direct current is connected to the grid.
The power supply margin eta of the power supply subarea is determined according to the following formula:
in the above formula, PTmaxFor all active power of the down-converter at maximum power supply capacity of the network, PT0Active power of all the downward-fed transformers in the initial state of the power grid is obtained;
wherein, the active power P of all the downward-poured transformers when the maximum power supply capacity of the power grid is determined according to the following formulaTmax：
PTmax＝Pmax-Gmax
In the above formula, PmaxFor maximum power supply capacity of the grid, GmaxAnd all the corresponding power of the generator at the maximum power supply capacity of the power grid.
The power supply section includes: a first power supply section and a second power supply section.
Specifically, the first determining unit includes:
the first determining module is used for taking the power supply subarea with large power supply margin of a power grid in the power supply subareas as a flexible direct-current sending-end power grid and taking the power supply subarea with small power supply margin of the power grid as a flexible direct-current receiving-end power grid.
The second determination unit includes:
a second determining module for determining the lower limit P of the flexible DC rated power according to the following formulaNmin：
PNmin＝Pr-max-Pr-max-N-1
In the above formula, Pr-maxThe maximum power receiving capacity P of a flexible direct current grid-connected front receiving end power gridr-max-N-1The maximum power receiving capacity is the maximum power receiving capacity of any lower-input transformer in a receiving-end power grid or any main power plant under the condition of loss;
a third determination module forDetermining the upper limit P of the rated power of the flexible direct current according to the following formulaNmax：
PNmax＝Psmax-Gs0-PTs0
In the above formula, PsmaxFor maximum power receiving capacity, G, of flexible DC grid-connected front-end power grids0Is the power of all generators of the sending end power grid in the initial state, PTs0All the power of the transformer is input to the power grid at the transmitting end in the initial state;
the soft DC rated power limit condition is PNmin≤PN≤PNmaxWherein P isNThe power is flexible DC rated power.
The third determination unit includes:
the first selection module is used for selecting the bus as a flexible direct current landing bus of the flexible direct current receiving end power grid after the flexible direct current is connected to the bus in the receiving end power grid, if the power reduction amount of the power injection transformer which is fully loaded in the flexible direct current receiving end power grid at first is the largest and the power supply capacity of the flexible direct current receiving end power grid is the largest;
and the second selection module is used for selecting the bus which can bear the flexible direct current rated capacity and is closest to the power supply in the subarea in the collection channel as the flexible direct current drop point bus of the flexible direct current sending end power grid.
The checking unit comprises:
and the checking module is used for performing safety and stability checking on the flexible direct current transmitting and receiving end power grid by utilizing the system N-1 fault, the flexible direct current single-stage and bipolar latching fault.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting the same, and although the present invention is described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: modifications and equivalents may be made to the embodiments of the invention without departing from the spirit and scope of the invention, which is to be covered by the claims.
Claims (8)
1. A flexible direct current configuration method for power supply partition interconnection is characterized by comprising the following steps:
determining a flexible direct current transmitting and receiving end power grid according to the power grid power supply margin of the power supply subarea;
determining upper and lower limits of flexible direct current rated power, and determining a flexible direct current rated power limiting condition by using the upper and lower limits of the flexible direct current rated power;
respectively determining flexible direct current drop point buses of a flexible direct current transmission and receiving end power grid;
after the flexible direct current is connected to the grid, safety and stability check are carried out on the flexible direct current transmission and receiving end power grid;
the power supply section includes: a first power supply section and a second power supply section;
the method for determining the flexible direct current transmission and receiving end power grid according to the power grid power supply margin of the power supply partition comprises the following steps:
taking the power supply subarea with large power supply margin of a power grid in the power supply subareas as a flexible direct-current transmitting end power grid, and taking the power supply subarea with small power supply margin of the power grid as a flexible direct-current receiving end power grid;
the flexible direct current drop point bus for respectively determining the flexible direct current transmission and receiving end power grid comprises the following steps:
after the flexible direct current is connected to a bus in a receiving-end power grid, if the power reduction amount of a power injection transformer which is fully loaded in the flexible direct current receiving-end power grid at first is the largest and the power supply capacity of the flexible direct current receiving-end power grid is the largest, selecting the bus as a flexible direct current drop point bus of the flexible direct current receiving-end power grid;
and selecting a bus which can bear the flexible direct current rated capacity and is closest to the power supply in the subarea as a flexible direct current drop point bus of the flexible direct current transmission end power grid.
2. The method of claim 1, wherein the grid supply margin η for a supply partition is determined as follows:
in the above formula, PT maxFor all active power of the down-converter at maximum power supply capacity of the network, PT0Active power of all the downward-fed transformers in the initial state of the power grid is obtained;
wherein, the active power P of all the downward-poured transformers when the maximum power supply capacity of the power grid is determined according to the following formulaT max：
PT max＝Pmax-Gmax
In the above formula, PmaxFor maximum power supply capacity of the grid, GmaxAnd all the corresponding power of the generator at the maximum power supply capacity of the power grid.
3. The method of claim 1, wherein the determining upper and lower flexible DC rated power limits and the determining flexible DC rated power limiting conditions using the upper and lower flexible DC rated power limits comprises:
determining the lower limit P of the rated power of the flexible direct current according to the following formulaN min：
PN min＝Pr-max-Pr-max-N-1
In the above formula, Pr-maxThe maximum power receiving capacity P of a flexible direct current grid-connected front receiving end power gridr-max-N-1The maximum power receiving capacity is the maximum power receiving capacity of any lower-input transformer in a receiving-end power grid or any main power plant under the condition of loss;
determining the upper limit P of the rated power of the flexible direct current according to the following formulaN max：
PN max＝Psmax-Gs0-PTs0
In the above formula, PsmaxFor maximum power receiving capacity, G, of flexible DC grid-connected front-end power grids0Is the power of all generators of the sending end power grid in the initial state, PTs0All the power of the transformer is input to the power grid at the transmitting end in the initial state;
the soft DC rated power limit condition is PN min≤PN≤PN maxWherein P isNThe power is flexible DC rated power.
4. The method of claim 1, wherein the safety and stability check of the flexible direct current transmission and reception end power grid after the flexible direct current grid connection comprises:
and (3) performing safety and stability check on the flexible direct current transmitting and receiving end power grid by using the system N-1 fault and the flexible direct current single-stage and bipolar locking faults.
5. A flexible dc configuration apparatus for interconnecting power supply partitions, the apparatus comprising:
the first determining unit is used for determining a flexible direct current transmitting and receiving end power grid according to the power grid power supply margin of the power supply partition;
the second determining unit is used for determining the upper limit and the lower limit of the flexible direct current rated power and determining the limiting condition of the flexible direct current rated power by utilizing the upper limit and the lower limit of the flexible direct current rated power;
the third determining unit is used for respectively determining flexible direct current drop point buses of the flexible direct current transmission and receiving end power grid;
the checking unit is used for performing safety and stability checking on the flexible direct current transmission and receiving end power grid after the flexible direct current is connected to the grid;
the power supply section includes: a first power supply section and a second power supply section;
the first determination unit includes:
the first determining module is used for taking the power supply subarea with large power supply margin of a power grid in the power supply subareas as a flexible direct-current transmitting-end power grid and taking the power supply subarea with small power supply margin of the power grid as a flexible direct-current receiving-end power grid;
the third determination unit includes:
the first selection module is used for selecting the bus as a flexible direct current landing bus of the flexible direct current receiving end power grid after the flexible direct current is connected to the bus in the receiving end power grid, if the power reduction amount of the power injection transformer which is fully loaded in the flexible direct current receiving end power grid at first is the largest and the power supply capacity of the flexible direct current receiving end power grid is the largest;
and the second selection module is used for selecting the bus which can bear the flexible direct current rated capacity and is closest to the power supply in the subarea in the collection channel as the flexible direct current drop point bus of the flexible direct current sending end power grid.
6. The apparatus of claim 5, wherein the grid supply margin η for a supply partition is determined as follows:
in the above formula, PT maxFor all active power of the down-converter at maximum power supply capacity of the network, PT0Active power of all the downward-fed transformers in the initial state of the power grid is obtained;
wherein, the active power P of all the downward-poured transformers when the maximum power supply capacity of the power grid is determined according to the following formulaT max：
PT max＝Pmax-Gmax
In the above formula, PmaxFor maximum power supply capacity of the grid, GmaxAnd all the corresponding power of the generator at the maximum power supply capacity of the power grid.
7. The apparatus of claim 5, wherein the second determining unit comprises:
a second determining module for determining the lower limit P of the flexible DC rated power according to the following formulaN min：
PN min＝Pr-max-Pr-max-N-1
In the above formula, Pr-maxThe maximum power receiving capacity P of a flexible direct current grid-connected front receiving end power gridr-max-N-1The maximum power receiving capacity is the maximum power receiving capacity of any lower-input transformer in a receiving-end power grid or any main power plant under the condition of loss;
a third determining module for determining the upper limit P of the flexible DC rated power according to the following formulaN max：
PN max＝Psmax-Gs0-PTs0
In the above formula, PsmaxFor flexible DC grid-connected front-end power gridPower receiving capacity, Gs0Is the power of all generators of the sending end power grid in the initial state, PTs0All the power of the transformer is input to the power grid at the transmitting end in the initial state;
the soft DC rated power limit condition is PN min≤PN≤PN maxWherein P isNThe power is flexible DC rated power.
8. The apparatus of claim 5, wherein the verification unit comprises:
and the checking module is used for performing safety and stability checking on the flexible direct current transmitting and receiving end power grid by utilizing the system N-1 fault, the flexible direct current single-stage and bipolar latching fault.
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| CN108182493B (en) * | 2017-12-29 | 2023-11-14 | 国网宁夏电力有限公司 | Method and system for selecting address of interconnection point of power supply partition |
| CN108493976B (en) * | 2018-02-28 | 2021-06-15 | 中国电力科学研究院有限公司 | Method and system for flexible direct current back-to-back device drop point and capacity configuration |
| CN108988374B (en) * | 2018-06-22 | 2021-11-02 | 国家电网公司华中分部 | Optimal configuration method for position of flexible direct current interconnection device in power transmission section |
| CN111987720B (en) * | 2020-08-26 | 2021-11-30 | 国网江苏省电力有限公司 | Method for evaluating power receiving and power supply margin intervals of receiving-end power grid under constraint of multichannel quota |
| CN112952887B (en) * | 2021-02-05 | 2023-05-16 | 国网四川省电力公司经济技术研究院 | Method and system for evaluating direct current bearing capacity of power grid at transmitting end |
| CN113922409B (en) * | 2021-10-19 | 2024-03-22 | 国网江苏省电力有限公司 | Constant volume method for urban power grid multi-partition flexible interconnection converter station |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104934982A (en) * | 2015-05-21 | 2015-09-23 | 广东电网有限责任公司电网规划研究中心 | Direct current partitioning method for multi-direct current feed-in system |
| CN106451446A (en) * | 2016-12-07 | 2017-02-22 | 天津大学 | Constant volume method of urban power grid district-dividing interconnection device based on flexible direct current technology |
| CN106786557A (en) * | 2017-01-23 | 2017-05-31 | 中国电力科学研究院 | A kind of extra-high voltage is layered D.C. capacity and drop point system of selection and system |
| CN106875287A (en) * | 2015-12-11 | 2017-06-20 | 中国电力科学研究院 | A kind of power system switched-mode power supply capacity judging method |
| CN106911131A (en) * | 2015-12-22 | 2017-06-30 | 国网智能电网研究院 | A kind of em ergency power support control method of AC network subregion interconnect device |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102969733B (en) * | 2012-11-08 | 2014-12-03 | 南京南瑞继保电气有限公司 | Coordination control method of multiterminal flexible direct current power transmission system |
-
2017
- 2017-07-10 CN CN201710556583.XA patent/CN107453383B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104934982A (en) * | 2015-05-21 | 2015-09-23 | 广东电网有限责任公司电网规划研究中心 | Direct current partitioning method for multi-direct current feed-in system |
| CN106875287A (en) * | 2015-12-11 | 2017-06-20 | 中国电力科学研究院 | A kind of power system switched-mode power supply capacity judging method |
| CN106911131A (en) * | 2015-12-22 | 2017-06-30 | 国网智能电网研究院 | A kind of em ergency power support control method of AC network subregion interconnect device |
| CN106451446A (en) * | 2016-12-07 | 2017-02-22 | 天津大学 | Constant volume method of urban power grid district-dividing interconnection device based on flexible direct current technology |
| CN106786557A (en) * | 2017-01-23 | 2017-05-31 | 中国电力科学研究院 | A kind of extra-high voltage is layered D.C. capacity and drop point system of selection and system |
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