CN107453383A - A kind of flexible direct current collocation method and device for power supply zone interconnection - Google Patents

Abstract

The invention relates to a flexible DC configuration method and device for interconnection of power supply partitions. The method includes: determining the flexible DC sending and receiving end power grid according to the power supply margin of the power supply partition; determining the upper and lower limits of the flexible DC rated power, and using the The upper and lower limits of the flexible DC rated power determine the limit conditions of the flexible DC rated power; respectively determine the flexible DC drop-point busbars of the flexible DC sending and receiving end grid; after the flexible DC is connected to the grid, check the safety and stability of the flexible DC sending and receiving end grid; the invention provides The technical scheme of connecting the two power supply partitions through flexible DC can avoid the generation of electromagnetic ring network and suppress the short-circuit current from exceeding the standard. Partition support for failed partitions.

Description

A flexible DC configuration method and device for power supply partition interconnection

technical field

The invention relates to the field of power supply partitions, in particular to a flexible DC configuration method and device for interconnection of power supply partitions.

Background technique

With the development of the power grid, when the high-level voltage network of the power system has not yet met the reliability of power supply or is not strong enough, in order to make reasonable use of existing resources to ensure power transmission capacity and meet user requirements for power consumption, high and low voltage will be formed. Electromagnetic ring network.

The electromagnetic ring network has its significance in the early stage of the new voltage level, which is conducive to improving the power supply capacity of the system and reducing the reserve capacity. With the development of higher-voltage power grids and the increasing transmission load, the electromagnetic ring network has become a serious accident hazard in the power system. For example, after the high-level voltage line is disconnected, a large number of loads carried by it will be transferred to the first-level voltage line, and the power of the low-voltage line may exceed its thermal stability limit.

The "Guidelines for the Safety and Stability of Electric Power Systems" stipulates that with the construction of a high-level voltage grid, the next-level voltage grid should gradually realize partition operation and maintain communication between adjacent partitions as backup. A number of provincial network companies in China have carried out the research and implementation of the electromagnetic ring network solution in combination with the conditions of each region.

Usually, the transformers are operated separately or the low-voltage buses of the transformers are operated in sections to form low-voltage power supply partitions, so as to de-loop the electromagnetic ring network, control the short-circuit current level, and improve the overall power supply capacity. But this method has the following disadvantages:

(1) The power supply reliability of each district will decrease accordingly;

(2) When there is a problem with the transformer in a certain partition, the partition loses the power point and only supplies power through other partitions through the hot standby line, which cannot meet the load demand and loses a large amount of load;

(3) The electrical connection between the districts is weakened, and the voltage support ability is reduced.

As a new generation of DC transmission technology, flexible DC transmission technology can realize independent control of active power and reactive power, and does not require reactive power compensation devices. Combining the technical characteristics and engineering practice of flexible DC transmission technology, flexible DC transmission technology is very suitable for scenarios such as renewable energy grid integration and urban grid power supply.

Contents of the invention

The present invention provides a flexible DC configuration method and device for the interconnection of power supply partitions. The purpose is to connect two power supply partitions through flexible DC, which can avoid the generation of electromagnetic ring network, suppress the short-circuit current from exceeding the standard, and at the same time, when a fault occurs in a partition, Active and reactive power support can be provided through flexible DC power control, and another partition can support the fault partition.

The object of the present invention is to adopt following technical scheme to realize:

A flexible DC configuration method for interconnection of power supply partitions, the improvement of which includes:

Determine the flexible DC sending and receiving end grid according to the grid power supply margin of the power supply partition;

Determine the upper and lower limits of the flexible DC rated power, and use the upper and lower limits of the flexible DC rated power to determine the limiting conditions for the flexible DC rated power;

Respectively determine the flexible DC drop-point bus of the flexible DC sending and receiving end grid;

After the flexible DC is connected to the grid, the safety and stability of the flexible DC sending and receiving end grid is checked.

Preferably, the grid power supply margin η of the power supply partition is determined as follows:

In the above formula, P _Tmax is the active power of all transformers at the maximum power supply capacity of the grid, and P _T0 is the active power of all transformers in the initial state of the grid;

Among them, the active power P _Tmax of all betting transformers when the maximum power supply capacity of the grid is determined by the following formula:

P _Tmax =P _max -G _max

In the above formula, P _max is the maximum power supply capacity of the grid, and G _max is the power of all generators corresponding to the maximum power supply capacity of the grid.

Preferably, the power supply partition includes: a first power supply partition and a second power supply partition.

Further, the determination of the flexible DC sending and receiving end grid according to the grid power supply margin of the power supply partition includes:

Among the power supply partitions, the power supply partition with a large grid power supply margin is used as a flexible DC sending-end grid, and the power supply partition with a small grid power supply margin is used as a flexible DC receiving-end grid.

Preferably, the determining the upper and lower limits of the flexible DC rated power, and using the upper and lower limits of the flexible DC rated power to determine the limiting conditions of the flexible DC rated power include:

Determine the flexible DC rated power lower limit P _Nmin according to the following formula:

P _Nmin =P _r-max -P _r-max-N-1

In the above formula, P _r-max is the maximum power receiving capacity of the receiving end grid before the flexible DC grid connection, and P _r-max-N-1 is the power receiving capacity under the condition of any betting transformer loss or any main power plant loss in the receiving end grid Maximum receiving capacity;

Determine the flexible DC rated power upper limit P _Nmax according to the following formula:

P _Nmax ＝P _smax -G _s0 -P _Ts0

In the above formula, P _smax is the maximum receiving capacity of the sending-end grid before flexible DC grid-connection, G _s0 is the power of all generators in the sending-end grid in the initial state, and P _Ts0 is the power of all transformers in the sending-end grid in the initial state;

Then the limiting condition of the flexible DC rated power is P _Nmin ≤ P _{N ≤} P _Nmax , where P _N is the flexible DC rated power.

Preferably, the respectively determining the flexible DC drop-point busbars of the flexible DC sending and receiving end grid includes:

After the flexible DC is connected to the busbar in the receiving-end grid, if the power reduction of the first fully-loaded power betting transformer in the flexible DC receiving-end grid is the largest, and the power supply capacity of the flexible DC receiving-end grid is the largest, then the busbar is selected as the flexible DC The flexible DC drop-point busbar of the receiving power grid;

The bus that can carry the rated capacity of flexible DC and is closest to the power supply in the zone is selected as the flexible DC drop-point bus of the flexible DC sending-end grid.

Preferably, after the flexible DC is connected to the grid, the safety and stability of the flexible DC sending and receiving end grid is checked, including:

Using system N-1 faults, flexible DC single-stage, bipolar blocking faults to check the safety and stability of the flexible DC sending and receiving end power grid.

A flexible DC configuration device for interconnection of power supply partitions, the improvement of which is that the device includes:

The first determining unit is configured to determine the flexible DC sending and receiving end grid according to the grid power supply margin of the power supply zone;

The second determination unit is configured to determine the upper and lower limits of the flexible DC rated power, and use the upper and lower limits of the flexible DC rated power to determine the limiting conditions of the flexible DC rated power;

The third determination unit is used to respectively determine the flexible DC drop-point buses of the flexible DC sending and receiving end grid;

The checking unit is used to check the safety and stability of the flexible DC sending and receiving end grid after the flexible DC grid is connected.

Preferably, the grid power supply margin η of the power supply partition is determined as follows:

In the above formula, P _Tmax is the active power of all transformers at the maximum power supply capacity of the grid, and P _T0 is the active power of all transformers in the initial state of the grid;

Among them, the active power P _Tmax of all betting transformers when the maximum power supply capacity of the grid is determined by the following formula:

P _Tmax =P _max -G _max

In the above formula, P _max is the maximum power supply capacity of the grid, and G _max is the power of all generators corresponding to the maximum power supply capacity of the grid.

Preferably, the power supply partition includes: a first power supply partition and a second power supply partition.

Further, the first determination unit includes:

The first determination module is configured to use a power supply zone with a large grid power supply margin among the power supply zones as a flexible DC sending-end grid, and a power supply zone with a small grid power supply margin as a flexible DC receiving-end grid.

Preferably, the second determining unit includes:

The second determination module is used to determine the flexible DC rated power lower limit P _Nmin according to the following formula:

P _Nmin =P _r-max -P _r-max-N-1

In the above formula, P _r-max is the maximum power receiving capacity of the receiving end grid before the flexible DC grid connection, and P _r-max-N-1 is the power receiving capacity under the condition of any betting transformer loss or any main power plant loss in the receiving end grid Maximum receiving capacity;

The third determination module is used to determine the flexible DC rated power upper limit P _Nmax according to the following formula:

P _Nmax ＝P _smax -G _s0 -P _Ts0

In the above formula, P _smax is the maximum receiving capacity of the sending-end grid before flexible DC grid-connection, G _s0 is the power of all generators in the sending-end grid in the initial state, and P _Ts0 is the power of all transformers in the sending-end grid in the initial state;

Then the limiting condition of the flexible DC rated power is P _Nmin ≤ P _{N ≤} P _Nmax , where P _N is the flexible DC rated power.

Preferably, the third determination unit includes:

The first selection module is used for after the flexible DC is connected to the busbar in the receiving-end grid, if the first fully-loaded power betting transformer in the flexible DC receiving-end grid has the largest power reduction, and the power supply capacity of the flexible DC receiving-end grid is the largest, Then select the busbar as the flexible DC drop-point busbar of the flexible DC receiving end grid;

The second selection module is used to select the busbar that can carry the rated capacity of flexible DC in the converging channel and is closest to the power supply in the partition as the flexible DC drop-point busbar of the flexible DC sending-end grid.

Preferably, the checking unit includes:

The checking module is used to check the safety and stability of the flexible DC sending and receiving end power grid by using the system N-1 fault and flexible DC single-stage and double-pole blocking faults.

Beneficial effects of the present invention:

The technical solution provided by the invention uses the power supply margin of the power supply partition to determine the flexible DC sending and receiving end grid, and uses the upper and lower limits of the flexible DC rated power to determine the flexible DC rated power limit conditions, and at the same time, determines the flexible DC sending and receiving end grid. The drop-point busbar defines the transmission direction, rated capacity and drop point of the sending and receiving ends of the flexible DC, which can improve the active and reactive power support capabilities of each zone, avoid the generation of electromagnetic ring network, and suppress the short-circuit current exceeding the standard, and at the same time appear in a certain zone In the event of a fault, flexible DC power control can be used to provide active and reactive power support, enabling another partition to support the fault partition and improving power supply reliability.

Description of drawings

Fig. 1 is a flow chart of a flexible DC configuration method for power supply partition interconnection according to the present invention;

Fig. 2 is a schematic diagram of the grid structure of the HC partition and the CC partition of the BJ power grid in the embodiment of the present invention;

Fig. 3 is a schematic diagram of the grid structure of the HC partition and the CC partition 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 power supply partition interconnection according to the present invention.

detailed description

The specific implementation manners of the present invention will be described in detail below in conjunction with the accompanying drawings.

In order to make the purpose, 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 in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The existing grid power supply partition method has the problems of reduced reliability of power supply in each partition and insufficient support capacity of active and reactive power between partitions. The present invention provides a flexible DC configuration method for interconnection of power supply partitions, which connects two power supply partitions through flexible DC , can avoid the generation of electromagnetic ring network, suppress the short-circuit current from exceeding the standard, and at the same time, when a fault occurs in a certain partition, it can provide active and reactive power support through flexible DC power control, and realize the support of another partition to the faulty partition, as shown in Figure 1 display, including:

101. Determine the flexible DC sending and receiving end grid according to the grid power supply margin of the power supply zone;

102. Determine the upper and lower limits of the flexible DC rated power, and use the upper and lower limits of the flexible DC rated power to determine the limiting conditions for the flexible DC rated power;

103. Determine the flexible DC drop-point buses of the flexible DC sending and receiving end grids respectively;

104. After the flexible DC is connected to the grid, check the safety and stability of the flexible DC sending and receiving end grid.

Among them, the grid power supply margin η of the power supply partition is determined according to the following formula:

In the above formula, P _Tmax is the active power of all transformers at the maximum power supply capacity of the grid, and P _T0 is the active power of all transformers in the initial state of the grid;

Among them, the active power P _Tmax of all betting transformers when the maximum power supply capacity of the grid is determined by the following formula:

P _Tmax =P _max -G _max

In the above formula, P _max is the maximum power supply capacity of the grid, and G _max is the power of all generators corresponding to the maximum power supply capacity of the grid.

The power supply partition includes: a first power supply partition and a second power supply partition.

The technical solution provided by the present invention selects a flexible DC sending and receiving end grid between two power supply partitions. Therefore, the step 101 includes:

Among the power supply partitions, the power supply partition with a large grid power supply margin is used as a flexible DC sending-end grid, and the power supply partition with a small grid power supply margin is used as a flexible DC receiving-end grid.

The step 102 includes:

Determine the flexible DC rated power lower limit P _Nmin according to the following formula:

P _Nmin =P _r-max -P _r-max-N-1

In the above formula, P _r-max is the maximum power receiving capacity of the receiving end grid before the flexible DC grid connection, and P _r-max-N-1 is the power receiving capacity under the condition of any betting transformer loss or any main power plant loss in the receiving end grid Maximum receiving capacity;

Among them, the maximum power receiving capacity P _r-max of the receiving-end grid before flexible DC grid-connection is the total load corresponding to the load power of any transformer when the load power of the receiving-end grid increases according to the constant power factor, and the receiving-end The maximum power receiving capacity P _r-max-N-1 under the condition of loss of any betting transformer or loss of any main power plant in the power grid is N-1 mode of the receiving end power grid. When the load increases according to the constant power factor, the load of any transformer When the power reaches the thermal stability limit, take the minimum value corresponding to the total load.

Determine the flexible DC rated power upper limit P _Nmax according to the following formula:

P _Nmax ＝P _smax -G _s0 -P _Ts0

In the above formula, P _smax is the maximum receiving capacity of the sending-end grid before flexible DC grid-connection, G _s0 is the power of all generators in the sending-end grid in the initial state, and P _Ts0 is the power of all transformers in the sending-end grid in the initial state;

Among them, the maximum power receiving capacity P _smax of the sending-end power grid before flexible DC grid-connection is the total load corresponding to when the load power of any transformer reaches the thermal stability limit when the load of the sending-end power grid increases according to the constant power factor;

Then the limiting condition of the flexible DC rated power is P _Nmin ≤ P _{N ≤} P _Nmax , where P _N is the flexible DC rated power.

The step 103 includes:

After the flexible DC is connected to the busbar in the receiving-end grid, if the power reduction of the first fully-loaded power betting transformer in the flexible DC receiving-end grid is the largest, and the power supply capacity of the flexible DC receiving-end grid is the largest, then the busbar is selected as the flexible DC The flexible DC drop-point busbar of the receiving power grid;

The bus that can carry the rated capacity of flexible DC and is closest to the power supply in the zone is selected as the flexible DC drop-point bus of the flexible DC sending-end grid.

The step 4 includes:

Using system N-1 faults, flexible DC single-stage, bipolar blocking faults to check the safety and stability of the flexible DC sending and receiving end power grid.

The present invention provides an embodiment of a flexible DC configuration method for the interconnection of power supply partitions, analyzes and calculates the BJ power grid, and proposes a configuration scheme for applying flexible DC interconnection to BJ220kV power supply partitions. The grid structure of the HC partition and the CC partition of the BJ power grid is as follows As shown in Figure 2, there are three 500kV/220kV power transformers in the CC division, namely CP1, CP2 and CB2, with rated powers of 800MW, 800MW and 1200MW respectively; there are two 500kV/220kV power transformers in the HC division, respectively The rated power of HD2 and CP3 is 1200MW.

Step 1: Selection of the power grid at the flexible DC sending and receiving end.

Calculate the power supply margins of the CC partition and the HC partition respectively.

For the CC partition, the load increases according to the constant power factor. When the active load increases to 3300MW, the power of the CP2 main transformer reaches 800MW and reaches the limit of thermal stability, then P _max-CC is 3300MW. At this time, the output of all generators in the CC partition is G _{max- CC} is 795MW, then PTmax _-CC is 2505MW. According to the preliminary power flow test, CP1, CP2 and CB2 are 252.1, 255.4 and 297.6MW respectively, that is, PT0 _-CC = 805MW, it can be known that:

Similarly, for HC partition, P _max-HC is 3870MW, G _max-HC is 1875MW, P _Tmax-HC is 1995MW, P _T0-HC is 950MW, then η _HC is 1.10, so CC partition is selected as the interconnection flexible DC The sending end of the HC partition serves as the receiving end of the interconnected flexible DC.

Step 2: Selection of flexible DC rated capacity.

(1) Determine the lower limit of the flexible DC rated power through the receiving end grid.

From step 1, it can be seen that the maximum power receiving capacity P _r-max of the HC partition of the receiving end grid before the flexible DC grid connection is 3830MW. The results of calculating the maximum power receiving capacity of the receiving end power grid under the conditions of different power transformers and main power plants are shown in Table 1:

Table 1 The maximum power receiving capacity of the receiving end power grid under the conditions of different transformers and main power plant losses

serial number N-1 element Power receiving capacity (MW) 1 CP3 2855 2 HD2 2860 3 GJ factory 1 machine 3560 4 1 machine in JN factory 3585

Then P _r-max-N-1 =2855MW, correspondingly, the lower limit P _Nmin of the flexible DC rated power is 975MW.

(2) Determine the upper limit of the flexible DC rated power through the power grid at the sending end.

It can be seen from step 1 that the maximum power receiving capacity P _s-max of the CC partition of the sending-end power grid before flexible DC grid-connection is 3870 MW, P _Ts0 is 950 MW, and G _s0 is 785 MW from the power flow results, and the upper limit of the flexible DC rated power P _Nmax is:

P _Nmax ＝P _smax -G _s0 -P _Ts0

=3870-785-950

=2135

Therefore, when providing power support for other partitions, it will not affect the safe power supply of the power grid in this partition.

3) Combined with the different requirements of the sending-end power grid and the receiving-end power grid, the flexible DC rated power P _N satisfies: 975≤P _N≤2135 ; combined with the flexible DC engineering practice, the flexible DC rated power P _N is determined to be 1000MW.

Step 3: Select the landing point of the flexible DC sending and receiving terminal.

(1) Calculate the improvement of the power supply capacity limit conditions of the original receiving end power grid after calculating the different busbars at the flexible DC receiving end. The flexible DC rated power _PN is 1000MW. Considering economy and safety, the busbar with heavy load and many evacuation channels should be selected as the receiving end drop point. Initially select the XST, SZ and KYH buses, and calculate the improvement of the power supply capacity limit conditions after the flexible DC is respectively connected to these buses, as shown in Table 2:

Table 2 Improvement of power supply capacity limit conditions after flexible DC is connected to different buses

serial number drop bus CP2 main transformer power variable (MW) 1 XST -584.3 2 SZ -522.8 3 KYH -497.7

(2) Calculate the power supply capacity of the receiving end grid after the flexible DC receiving end is placed on different buses, and the results are shown in Table 3:

Table 3 HC power supply capacity after flexible DC is connected to different buses

serial number drop bus HC partition power supply capacity (MW) 1 XST 4970 2 SZ 4845 3 KYH 4755

(3) Integrating the influence of different busbars on the power supply capacity and limit conditions of the flexible DC landing point, the flexible DC receiving terminal landing point is selected. It can be seen from Table 2 and Table 3 that the XST busbar of the flexible DC drop point can reduce the power of the CP2 main transformer to the greatest extent, and increase the power supply capacity of the HC partition the most, so the XST busbar is selected as the drop point of the flexible DC receiving terminal.

(4) Combining the flexible DC transmission power and the grid structure of the sending end to determine the drop point of the flexible DC sending end. It can be seen from step 2 that the rated power of flexible DC is _1000MW . From the perspective of safety, bus nodes with more converging channels should be selected to reduce the transmission capacity of each channel; from the perspective of economy, one should be selected closer to the power supply. The bus node, so that the rich power can be directly sent to the load area of the receiving end through flexible DC to reduce losses. Considering the above two aspects, combined with the sending-end grid structure, after screening the sending-end bus nodes, it is found that the HJY bus is the closest to the power supply and has 3 converging channels, which is most suitable as a flexible DC sending-end bus.

Step 4: Check the safety and stability of the flexible DC grid after grid connection.

The safety and stability check after flexible DC grid connection mainly includes AC system N-1 faults, flexible DC single-stage and double-pole blocking faults, and the results are shown in Table 4:

Table 4 Safety and Stability Check Results of Transformer N-1 Not Allowed to Power Down After Fault

serial number Fault result 1 CP1 system stability 2 CP2 system stability 3 CP3 system stability 4 CB2 system stability 5 HD2 system stability 6 Soft Straight Single Pole Latching system stability 7 Soft Straight Bipolar Latching system stability

Figure 3 shows the grid structure of HC partition and CC partition after flexible DC grid connection.

The present invention also provides a flexible DC configuration device for power supply partition interconnection, as shown in Figure 4, the device includes:

The first determining unit is configured to determine the flexible DC sending and receiving end grid according to the grid power supply margin of the power supply zone;

The second determination unit is configured to determine the upper and lower limits of the flexible DC rated power, and use the upper and lower limits of the flexible DC rated power to determine the limiting conditions of the flexible DC rated power;

The third determination unit is used to respectively determine the flexible DC drop-point buses of the flexible DC sending and receiving end grid;

The checking unit is used to check the safety and stability of the flexible DC sending and receiving end grid after the flexible DC grid is connected.

Among them, the grid power supply margin η of the power supply partition is determined according to the following formula:

In the above formula, P _Tmax is the active power of all transformers at the maximum power supply capacity of the grid, and P _T0 is the active power of all transformers in the initial state of the grid;

Among them, the active power P _Tmax of all betting transformers when the maximum power supply capacity of the grid is determined by the following formula:

P _Tmax =P _max -G _max

In the above formula, P _max is the maximum power supply capacity of the grid, and G _max is the power of all generators corresponding to the maximum power supply capacity of the grid.

The power supply partition includes: a first power supply partition and a second power supply partition.

Specifically, the first determining unit includes:

The first determination module is configured to use a power supply zone with a large grid power supply margin among the power supply zones as a flexible DC sending-end grid, and a power supply zone with a small grid power supply margin as a flexible DC receiving-end grid.

The second determination unit includes:

The second determination module is used to determine the flexible DC rated power lower limit P _Nmin according to the following formula:

P _Nmin =P _r-max -P _r-max-N-1

In the above formula, P _r-max is the maximum power receiving capacity of the receiving end grid before the flexible DC grid connection, and P _r-max-N-1 is the power receiving capacity under the condition of any betting transformer loss or any main power plant loss in the receiving end grid Maximum receiving capacity;

The third determination module is used to determine the flexible DC rated power upper limit P _Nmax according to the following formula:

P _Nmax ＝P _smax -G _s0 -P _Ts0

In the above formula, P _smax is the maximum receiving capacity of the sending-end grid before flexible DC grid-connection, G _s0 is the power of all generators in the sending-end grid in the initial state, and P _Ts0 is the power of all transformers in the sending-end grid in the initial state;

Then the limiting condition of the flexible DC rated power is P _Nmin ≤ P _{N ≤} P _Nmax , where P _N is the flexible DC rated power.

The third determination unit includes:

The first selection module is used for after the flexible DC is connected to the busbar in the receiving-end grid, if the first fully-loaded power betting transformer in the flexible DC receiving-end grid has the largest power reduction, and the power supply capacity of the flexible DC receiving-end grid is the largest, Then select the busbar as the flexible DC drop-point busbar of the flexible DC receiving end grid;

The second selection module is used to select the busbar that can carry the rated capacity of flexible DC in the converging channel and is closest to the power supply in the partition as the flexible DC drop-point busbar of the flexible DC sending-end grid.

The checking unit includes:

The checking module is used to check the safety and stability of the flexible DC sending and receiving end power grid by using the system N-1 fault and flexible DC single-stage and double-pole blocking faults.

Those skilled in the art should understand that the embodiments of the present application may be provided as methods, systems, or computer program products. 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, etc.) having computer-usable program code embodied therein.

The present application is described with reference to flowcharts and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present application. It should be understood that each procedure and/or block in the flowchart and/or block diagram, and a combination of procedures and/or blocks in the flowchart and/or block diagram can be realized by computer program instructions. These computer program instructions may be provided to a general purpose computer, special purpose computer, embedded processor, or processor of other programmable data processing equipment to produce a machine such that the instructions executed by the processor of the computer or other programmable data processing equipment produce a An apparatus for realizing the functions specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing apparatus to operate in a specific manner, such that the instructions stored in the computer-readable memory produce an article of manufacture comprising instruction means, the instructions The device realizes the function specified in one or more procedures of the flowchart and/or one or more blocks of the block diagram.

These computer program instructions can also be loaded onto a computer or other programmable data processing device, causing a series of operational steps to be performed on the computer or other programmable device to produce a computer-implemented process, thereby The instructions provide steps for implementing the functions specified in the flow chart or blocks of the flowchart and/or the block or blocks of the block diagrams.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that: the present invention can still be Any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention shall fall within the protection scope of the claims of the present invention.

Claims (14)

1. A flexible DC configuration method for interconnection of power supply partitions, characterized in that the method comprises: Determine the flexible DC sending and receiving end grid according to the grid power supply margin of the power supply partition; Determine the upper and lower limits of the flexible DC rated power, and use the upper and lower limits of the flexible DC rated power to determine the limiting conditions for the flexible DC rated power; Respectively determine the flexible DC drop-point bus of the flexible DC sending and receiving end grid; After the flexible DC is connected to the grid, the safety and stability of the flexible DC sending and receiving end grid is checked. 2. The method according to claim 1, characterized in that, the grid power supply margin n of the power supply partition is determined as follows: <mrow><mi>&amp;eta;</mi><mo>=</mo><mfrac><mrow><msub><mi>P</mi><mrow><mi>T</mi><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub><mo>-</mo><msub><mi>P</mi><mrow><mi>T</mi><mn>0</mn></mrow></msub></mrow><msub><mi>P</mi><mrow><mi>T</mi><mn>0</mn></mrow></msub></mfrac></mrow> In the above formula, P _Tmax is the active power of all transformers at the maximum power supply capacity of the grid, and P _T0 is the active power of all transformers in the initial state of the grid; Among them, the active power P _Tmax of all betting transformers when the maximum power supply capacity of the grid is determined by the following formula: P _Tmax =P _max -G _max In the above formula, P _max is the maximum power supply capacity of the grid, and G _max is the power of all generators corresponding to the maximum power supply capacity of the grid. 3. The method according to claim 1, wherein the power supply partition comprises: a first power supply partition and a second power supply partition. 4. The method according to claim 3, wherein said determining the flexible DC sending and receiving end grid according to the grid power supply margin of the power supply partition comprises: Among the power supply partitions, the power supply partition with a large grid power supply margin is used as a flexible DC sending-end grid, and the power supply partition with a small grid power supply margin is used as a flexible DC receiving-end grid. 5. The method according to claim 1, wherein the determining the upper and lower limits of the flexible DC rated power and using the upper and lower limits of the flexible DC rated power to determine the limiting conditions of the flexible DC rated power include: Determine the flexible DC rated power lower limit P _Nmin according to the following formula: P _Nmin =P _r-max -P _r-max-N-1 In the above formula, P _r-max is the maximum power receiving capacity of the receiving end grid before the flexible DC grid connection, and P _r-max-N-1 is the power receiving capacity under the condition of any betting transformer loss or any main power plant loss in the receiving end grid Maximum receiving capacity; Determine the flexible DC rated power upper limit P _Nmax according to the following formula: P _Nmax ＝P _smax -G _s0 -P _Ts0 In the above formula, P _smax is the maximum receiving capacity of the sending-end grid before flexible DC grid-connection, G _s0 is the power of all generators in the sending-end grid in the initial state, and P _Ts0 is the power of all transformers in the sending-end grid in the initial state; Then the limiting condition of the flexible DC rated power is P _Nmin ≤ P _{N ≤} P _Nmax , where P _N is the flexible DC rated power. 6. The method according to claim 1, characterized in that said respectively determining the flexible DC drop-point busbars of the flexible DC sending and receiving end power grid comprises: After the flexible DC is connected to the busbar in the receiving-end grid, if the power reduction of the first fully-loaded power betting transformer in the flexible DC receiving-end grid is the largest, and the power supply capacity of the flexible DC receiving-end grid is the largest, then the busbar is selected as the flexible DC The flexible DC drop-point busbar of the receiving power grid; The bus that can carry the rated capacity of flexible DC and is closest to the power supply in the zone is selected as the flexible DC drop-point bus of the flexible DC sending-end grid. 7. The method according to claim 1, characterized in that, after the flexible DC is connected to the grid, the safety and stability of the flexible DC sending and receiving end grid is checked, including: Using system N-1 faults, flexible DC single-stage, bipolar blocking faults to check the safety and stability of the flexible DC sending and receiving end power grid. 8. A flexible DC configuration device for power supply partition interconnection, characterized in that the device includes: The first determining unit is configured to determine the flexible DC sending and receiving end grid according to the grid power supply margin of the power supply zone; The second determination unit is configured to determine the upper and lower limits of the flexible DC rated power, and use the upper and lower limits of the flexible DC rated power to determine the limiting conditions of the flexible DC rated power; The third determination unit is used to respectively determine the flexible DC drop-point buses of the flexible DC sending and receiving end grid; The checking unit is used to check the safety and stability of the flexible DC sending and receiving end grid after the flexible DC grid is connected. 9. The device as claimed in claim 8, characterized in that, the grid power supply margin n of the power supply partition is determined by the following formula: <mrow><mi>&amp;eta;</mi><mo>=</mo><mfrac><mrow><msub><mi>P</mi><mrow><mi>T</mi><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub><mo>-</mo><msub><mi>P</mi><mrow><mi>T</mi><mn>0</mn></mrow></msub></mrow><msub><mi>P</mi><mrow><mi>T</mi><mn>0</mn></mrow></msub></mfrac></mrow> In the above formula, P _Tmax is the active power of all transformers at the maximum power supply capacity of the grid, and P _T0 is the active power of all transformers in the initial state of the grid; Among them, the active power P _Tmax of all betting transformers when the maximum power supply capacity of the grid is determined by the following formula: P _Tmax =P _max -G _max In the above formula, P _max is the maximum power supply capacity of the grid, and G _max is the power of all generators corresponding to the maximum power supply capacity of the grid. 10. The device according to claim 8, wherein the power supply partition comprises: a first power supply partition and a second power supply partition. 11. The device according to claim 10, wherein the first determining unit comprises: The first determination module is configured to use a power supply zone with a large grid power supply margin among the power supply zones as a flexible DC sending-end grid, and a power supply zone with a small grid power supply margin as a flexible DC receiving-end grid. 12. The device according to claim 8, wherein the second determining unit comprises: The second determination module is used to determine the flexible DC rated power lower limit P _Nmin according to the following formula: P _Nmin =P _r-max -P _r-max-N-1 In the above formula, P _r-max is the maximum power receiving capacity of the receiving end grid before the flexible DC grid connection, and P _r-max-N-1 is the power receiving capacity under the condition of any betting transformer loss or any main power plant loss in the receiving end grid Maximum receiving capacity; The third determination module is used to determine the flexible DC rated power upper limit P _Nmax according to the following formula: P _Nmax ＝P _smax -G _s0 -P _Ts0 In the above formula, P _smax is the maximum receiving capacity of the sending-end grid before flexible DC grid-connection, G _s0 is the power of all generators in the sending-end grid in the initial state, and P _Ts0 is the power of all transformers in the sending-end grid in the initial state; Then the limiting condition of the flexible DC rated power is P _Nmin ≤ P _{N ≤} P _Nmax , where P _N is the flexible DC rated power. 13. The device according to claim 8, wherein the third determining unit comprises: The first selection module is used for after the flexible DC is connected to the busbar in the receiving-end grid, if the first fully-loaded power betting transformer in the flexible DC receiving-end grid has the largest power reduction, and the power supply capacity of the flexible DC receiving-end grid is the largest, Then select the busbar as the flexible DC drop-point busbar of the flexible DC receiving end grid; The second selection module is used to select the busbar that can carry the rated capacity of flexible DC in the converging channel and is closest to the power supply in the partition as the flexible DC drop-point busbar of the flexible DC sending-end grid. 14. The device according to claim 8, wherein the checking unit comprises: The checking module is used to check the safety and stability of the flexible DC sending and receiving end power grid by using the system N-1 fault and flexible DC single-stage and double-pole blocking faults.