CN112260283B - Power transmission section tide adjusting method and device for power system - Google Patents

Power transmission section tide adjusting method and device for power system Download PDF

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Publication number
CN112260283B
CN112260283B CN202011136562.0A CN202011136562A CN112260283B CN 112260283 B CN112260283 B CN 112260283B CN 202011136562 A CN202011136562 A CN 202011136562A CN 112260283 B CN112260283 B CN 112260283B
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power
active
power generation
station
receiving end
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CN112260283A (en
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司大军
朱欣春
李玲芳
周俊东
孙鹏
游广增
陈义宣
陈姝敏
何烨
肖友强
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Yunnan Power Grid Co Ltd
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Yunnan Power Grid Co Ltd
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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
    • H02J3/04—Circuit arrangements for ac mains or ac distribution networks for connecting networks of the same frequency but supplied from different sources
    • H02J3/06—Controlling transfer of power between connected networks; Controlling sharing of load between connected networks
    • 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
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/381—Dispersed generators
    • 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
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
    • H02J3/48—Controlling the sharing of the in-phase component
    • 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
    • H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/10—Power transmission or distribution systems management focussing at grid-level, e.g. load flow analysis, node profile computation, meshed network optimisation, active network management or spinning reserve management

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Other Liquid Machine Or Engine Such As Wave Power Use (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The application provides a method and a device for adjusting power transmission section tide of a power system. The method comprises the following steps: and according to the voltage phase angles of all the power generation nodes in each power station, taking the power generation node corresponding to the maximum value of the voltage phase angles as a representative node of the power station, sequencing each power station according to the voltage phase angles of each representative node, and sequentially adjusting the active output of each power station according to the sequence which is least favorable for the stability of the power grid, thereby adjusting the section tide until the tide deviation is smaller than a preset threshold value. Therefore, the embodiment of the application utilizes the voltage phase angle to reflect the influence of the power generation node on the stability of the power grid, and when the tide is adjusted, the power generation node which is least favorable for the stability of the power grid is preferentially started, and the power generation node which is most favorable for the stability of the power grid is preferentially closed, so that the minimum section limit can be ensured, and the safety and the stability of the power grid are more favorable.

Description

Power transmission section tide adjusting method and device for power system
Technical Field
The application relates to the technical field of automatic processing of power systems, in particular to a method and a device for adjusting power transmission section tide of a power system.
Background
When the power system is scheduled and planned by a power system scheduling and planning department, in order to ensure the safety and stability of the power system, the power grid needs to be ensured to be kept stable in a transient state under the condition of a preset fault, and the transient stability of the power grid is generally ensured by controlling the power on a power transmission section. After a certain branch in the power grid is disconnected in a preset mode, the power grid is divided into two systems, the interface of the two systems is the power transmission section of the power grid, the power at the power transmission section represents the power transmitted between the two systems, and the power grid is possibly unstable in a transient state under a certain fault condition when the power transmitted at the power transmission section is overlarge, so that the section limit of the power grid at the power transmission section, namely the maximum value of the power transmitted at the power transmission section on the premise of keeping the transient state stable, needs to be analyzed.
The section limit is usually determined by adopting a tide adjustment mode, and the main adjustment process comprises the following steps: under a certain operation mode, carrying out transient stability analysis on the power grid under the initial tidal current value, and adjusting the tidal current value according to an analysis result, wherein if the power grid is transient stable, the tidal current value of the power transmission section is increased, if the power grid is transient unstable, the tidal current value of the power transmission section is reduced, after the adjustment of the tidal current value is completed, carrying out transient stability analysis on the power grid again, and continuously adjusting the tidal current value of the power transmission section according to an analysis result, so that the solution is continuously iterated, and finally determining the section limit.
The usual method for regulating the power flow is a sensitivity method, wherein the sensitivity method is used for calculating the power flow regulating quantity according to the target deviation and the sensitivity by calculating the sensitivity of the section power flow to the active output of each generator. In general, the order of active power adjustment is different for each power generation node, and the final determined section limit may have a large difference, so that when the section limit of the power system is solved, the section power flow needs to be adjusted in a mode which is least favorable for the stability of the power grid, and the minimum section limit is determined as far as possible, thereby ensuring the safety and stability of the power grid.
When the sensitivity method is used for tide adjustment, different influences on the result of the section limit caused by different power generation node active output adjustment sequences are not considered, so that the minimum section limit cannot be ensured.
Disclosure of Invention
The application provides a method and a device for adjusting power transmission section power flow of a power system, which can be used for solving the technical problem that the minimum section limit cannot be ensured because different power generation node active output adjustment sequences can cause different influences on the result of the section limit when the power flow adjustment is carried out in the prior art.
In a first aspect, an embodiment of the present application provides a method for adjusting a power transmission section power flow of a power system, where the method includes:
Carrying out power flow calculation on a power transmission section to be subjected to power flow adjustment to obtain a power flow result of the power transmission section; the tide results comprise a voltage phase angle of the power generation node, active power output of the power generation node and tide values of all branches in the power transmission section;
dividing a preset power grid into a transmitting end system and a receiving end system according to the active power flow direction at the power transmission section; the power transmission section comprises a plurality of branches; the power grid comprises a plurality of power stations; the power plant comprises a plurality of power generation nodes;
determining an initial tidal current value of the power transmission section according to the tidal current values of all the branches;
determining a maximum voltage phase angle from the voltage phase angles of all the power generation nodes in the power station, and taking the power generation node corresponding to the maximum voltage phase angle as a representative node of the power station;
determining a tide adjustment amount according to a preset target tide value and the initial tide value, and determining a transmitting end unit adjustment amount of a transmitting end system and a receiving end unit adjustment amount of a receiving end system according to the tide adjustment amount;
if the tide adjustment quantity is greater than zero, sequentially adjusting the active power output of each power generation node in the power generation station of the power transmission system according to the tide adjustment quantity of the power transmission unit, the active power output of each power generation node and the maximum active power output of each power generation node in the power generation station of the power transmission system from large to small according to the voltage phase angle of the representative node; the active output of the power station at the power transmitting end is the sum of the active outputs of all power generating nodes in the power station at the power transmitting end;
According to the adjustment quantity of the receiving end unit, the active power output of each generating node and the maximum active power output of each generating node in a receiving end power station of the receiving end system, sequentially adjusting the active power output of each receiving end power station according to the sequence of the voltage phase angle of the representative node from small to large; the active output of the receiving end power station is the sum of the active outputs of all power generation nodes in the receiving end power station;
according to the active power output adjusted by all power stations, determining an updated tidal current value after the power flow adjustment of the power transmission section;
determining a power flow deviation according to the target tide value and the updated power flow value;
if the power flow deviation is larger than or equal to a preset threshold value, setting the updated power flow value as an initial power flow value, and returning to the step of determining the power flow adjustment amount until the power flow deviation is smaller than the preset threshold value, and ending the power flow adjustment of the power transmission section.
In an implementation manner of the first aspect, the dividing, at the power transmission section, a preset power grid into a sending end system and a receiving end system according to an active power flow direction includes:
dividing a preset power grid into two systems at the power transmission section;
And taking the system for sending out power in the two systems as a transmitting end system and the system for flowing in power in the two systems as a receiving end system according to the active power flow direction.
In one implementation manner of the first aspect, the power flow adjustment amount, the sending end unit adjustment amount, and the receiving end unit adjustment amount are determined by:
wherein ΔP is the flow adjustment amount, P 1 For the target tidal current value, P 0 For the initial tidal current value, ΔP m For the adjustment of the sending end unit, delta P n And adjusting the quantity for the receiving end unit.
In an implementation manner of the first aspect, the sequentially adjusting the active output of each power plant is implemented by:
sequencing all the sending-end power stations according to the sequence of the voltage phase angles of the representative nodes from large to small to obtain a sending-end power station sequence;
determining an active adjustment value of a first power generation node according to the adjustment amount of the power unit of the first power generation end, the active output of the first power generation node in the first power generation end and the maximum active output of the first power generation node aiming at the first power generation end in the power generation end sequence;
if the active adjustment value of the first power generation node is not equal to the power transmission unit adjustment value, determining the active adjustment value of the next power generation node according to a first difference value between the power transmission unit adjustment value and the active adjustment value of the first power generation node, the active output of the next power generation node in the first power transmission station and the maximum active output of the next power generation node;
And if the sum of the active adjustment values of all the power generation nodes in the first power generation station is not equal to the power generation unit adjustment amount, continuously determining the active adjustment value of each power generation node in the second power generation station in the power generation station sequence until the sum of the active adjustment values of all the power generation nodes adjusted in the power generation station sequence is equal to the power generation unit adjustment amount, and adjusting the active output of the corresponding power generation node according to the active adjustment value of each power generation node adjusted in the power generation station sequence.
In an implementation manner of the first aspect, the sequentially adjusting the active output of each receiving-side power station is implemented by:
sequencing all receiving end power stations according to the sequence of the voltage phase angles of the representative nodes from small to large to obtain a receiving end power station sequence;
determining an active regulation value of a first receiving end power generation node according to the receiving end unit regulation quantity, the active power output of the first receiving end power generation node in the first receiving end power generation station and the maximum active power output of the first receiving end power generation node aiming at the first receiving end power generation station in the receiving end power generation station sequence;
If the active adjustment value of the first receiving end power generation node is not equal to the receiving end unit adjustment value, determining the active adjustment value of the next power generation node according to the difference value between the receiving end unit adjustment value and the active adjustment value of the first receiving end power generation node, the active output of the next power generation node in the first receiving end power generation station and the maximum active output of the next power generation node;
and if the sum of the active adjustment values of all the power generation nodes in the first receiving-end power station is not equal to the receiving-end unit adjustment amount, continuously determining the active adjustment value of each power generation node in the second receiving-end power station in the receiving-end power station sequence until the sum of the active adjustment values of all the power generation nodes adjusted in the receiving-end power station sequence is equal to the receiving-end unit adjustment amount, and adjusting the active output of the corresponding power generation node according to the active adjustment value of each power generation node adjusted in the receiving-end power station sequence.
In an implementation manner of the first aspect, the method further includes:
if the tide adjustment quantity is smaller than zero, sequentially adjusting the active power output of each power generation node in the power generation station of the power transmission system according to the tide adjustment quantity of the power transmission unit, the active power output of each power generation node and the maximum active power output of each power generation node in the power generation station of the power transmission system from small to large according to the voltage phase angle of the representative node; the active output of the power station at the power transmitting end is the sum of the active outputs of all power generating nodes in the power station at the power transmitting end;
According to the adjustment quantity of the receiving end unit, the active power output of each generating node and the maximum active power output of each generating node in a receiving end power station of the receiving end system, sequentially adjusting the active power output of each receiving end power station according to the sequence of the voltage phase angle of the representative node from large to small; the active output of the receiving end power station is the sum of the active outputs of all power generation nodes in the receiving end power station.
In a second aspect, an embodiment of the present application provides a device for adjusting a power transmission section power flow of a power system, where the device includes:
the preprocessing unit is used for carrying out power flow calculation on the power transmission section to be subjected to power flow adjustment to obtain a power flow result of the power transmission section; the tide results comprise a voltage phase angle of the power generation node, active power output of the power generation node and tide values of all branches in the power transmission section; dividing a preset power grid into a transmitting end system and a receiving end system according to the active power flow direction at the power transmission section; the power transmission section comprises a plurality of branches; the power grid comprises a plurality of power stations; the power plant comprises a plurality of power generation nodes; the method comprises the steps of carrying out a first treatment on the surface of the Determining an initial tidal current value of the power transmission section according to the tidal current values of all the branches;
The processing unit is used for determining a maximum voltage phase angle from the voltage phase angles of all the power generation nodes in the power station, and taking the power generation node corresponding to the maximum voltage phase angle as a representative node of the power station; determining a tide adjustment amount according to a preset target tide value and the initial tide value, and determining a transmitting end unit adjustment amount of a transmitting end system and a receiving end unit adjustment amount of a receiving end system according to the tide adjustment amount;
the first adjusting unit is used for adjusting the active power output of each power generation node in the power generation station of the power transmission system according to the power transmission unit adjusting amount, the active power output of each power generation node and the maximum active power output of each power generation node in sequence from large to small according to the voltage phase angle of the representative node if the power flow adjusting amount is larger than zero; the active output of the power station at the power transmitting end is the sum of the active outputs of all power generating nodes in the power station at the power transmitting end; according to the adjustment quantity of the receiving end unit, the active power output of each power generation node and the maximum active power output of each power generation node in the receiving end power station of the receiving end system, the active power output of each receiving end power station is sequentially adjusted according to the sequence of the voltage phase angles of the representative nodes from small to large; the active output of the receiving end power station is the sum of the active outputs of all power generation nodes in the receiving end power station;
The verification unit is used for determining an updated current value after the power transmission section tide adjustment according to the active power output after all power stations are adjusted; and determining a power flow deviation from the target tidal current value and the updated power flow value; and if the power flow deviation is greater than or equal to a preset threshold value, setting the updated power flow value as an initial power flow value, and returning to the step of determining the power flow adjustment amount until the power flow deviation is less than the preset threshold value, and ending the power flow adjustment of the power transmission section.
In an implementation manner of the second aspect, the preprocessing unit is specifically configured to:
dividing a preset power grid into two systems at the power transmission section;
and taking the system for sending out power in the two systems as a transmitting end system and the system for flowing in power in the two systems as a receiving end system according to the active power flow direction.
In one implementation manner of the second aspect, the tide adjustment amount, the sending end unit adjustment amount and the receiving end unit adjustment amount are determined by:
wherein ΔP is the flow adjustment amount, P 1 For the target tidal current value, P 0 For the initial tidal current value, ΔP m For the adjustment of the sending end unit, delta P n And adjusting the quantity for the receiving end unit.
In an implementation manner of the second aspect, the first adjusting unit is specifically configured to:
sequencing all the sending-end power stations according to the sequence of the voltage phase angles of the representative nodes from large to small to obtain a sending-end power station sequence;
determining an active adjustment value of a first power generation node according to the adjustment amount of the power unit of the first power generation end, the active output of the first power generation node in the first power generation end and the maximum active output of the first power generation node aiming at the first power generation end in the power generation end sequence;
if the active adjustment value of the first power generation node is not equal to the power transmission unit adjustment value, determining the active adjustment value of the next power generation node according to a first difference value between the power transmission unit adjustment value and the active adjustment value of the first power generation node, the active output of the next power generation node in the first power transmission station and the maximum active output of the next power generation node;
and if the sum of the active adjustment values of all the power generation nodes in the first power generation station is not equal to the power generation unit adjustment amount, continuously determining the active adjustment value of each power generation node in the second power generation station in the power generation station sequence until the sum of the active adjustment values of all the power generation nodes adjusted in the power generation station sequence is equal to the power generation unit adjustment amount, and adjusting the active output of the corresponding power generation node according to the active adjustment value of each power generation node adjusted in the power generation station sequence.
In an implementation manner of the second aspect, the first adjusting unit is specifically configured to:
sequencing all receiving end power stations according to the sequence of the voltage phase angles of the representative nodes from small to large to obtain a receiving end power station sequence;
determining an active regulation value of a first receiving end power generation node according to the receiving end unit regulation quantity, the active power output of the first receiving end power generation node in the first receiving end power generation station and the maximum active power output of the first receiving end power generation node aiming at the first receiving end power generation station in the receiving end power generation station sequence;
if the active adjustment value of the first receiving end power generation node is not equal to the receiving end unit adjustment value, determining the active adjustment value of the next power generation node according to the difference value between the receiving end unit adjustment value and the active adjustment value of the first receiving end power generation node, the active output of the next power generation node in the first receiving end power generation station and the maximum active output of the next power generation node;
and if the sum of the active adjustment values of all the power generation nodes in the first receiving-end power station is not equal to the receiving-end unit adjustment amount, continuously determining the active adjustment value of each power generation node in the second receiving-end power station in the receiving-end power station sequence until the sum of the active adjustment values of all the power generation nodes adjusted in the receiving-end power station sequence is equal to the receiving-end unit adjustment amount, and adjusting the active output of the corresponding power generation node according to the active adjustment value of each power generation node adjusted in the receiving-end power station sequence.
In an implementation manner of the second aspect, the apparatus further includes:
the second adjusting unit is used for adjusting the active power output of each power generation node in the power generation station of the power transmission system according to the power transmission unit adjusting amount, the active power output of each power generation node and the maximum active power output of each power generation node in sequence from small to large according to the voltage phase angle of the representative node if the power flow adjusting amount is smaller than zero; the active output of the power station at the power transmitting end is the sum of the active outputs of all power generating nodes in the power station at the power transmitting end;
according to the adjustment quantity of the receiving end unit, the active power output of each generating node and the maximum active power output of each generating node in a receiving end power station of the receiving end system, sequentially adjusting the active power output of each receiving end power station according to the sequence of the voltage phase angle of the representative node from large to small; the active output of the receiving end power station is the sum of the active outputs of all power generation nodes in the receiving end power station.
In this way, the embodiment of the application reflects the influence of the power generation node on the stability of the power grid through the voltage phase angle of the power generation node in the power grid, takes the power generation node with the largest voltage phase angle in each power station as the representative node of the power station, sorts the power stations according to the voltage phase angles of the representative nodes, and sequentially adjusts the active output of the power stations according to the order which is least favorable for the stability of the power grid, namely, carries out tide adjustment. The tide adjusting method can ensure that the minimum, namely the most conservative section limit is obtained, and is more beneficial to the safety and stability of the power grid.
Drawings
Fig. 1 is a schematic flow diagram corresponding to a method for adjusting power flow of a power transmission section of a power system according to an embodiment of the present application;
fig. 2 is a schematic structural diagram of a sending end system and a receiving end system according to an embodiment of the present application;
fig. 3 is a schematic structural diagram of a power transmission section tide adjusting device of a power system according to an embodiment of the present application.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the embodiments of the present application will be described in further detail with reference to the accompanying drawings.
In order to solve the problems in the prior art, the embodiment of the application provides a power transmission section power flow adjustment method of a power system, which is particularly used for solving the problems that the current adjustment method does not consider that different power generation node active power output adjustment sequences can cause different influences on the result of section limit, so that the minimum section limit cannot be ensured. Fig. 1 is a schematic flow chart corresponding to a method for adjusting power flow of a power transmission section of a power system according to an embodiment of the present application. The method specifically comprises the following steps:
and step 101, carrying out power flow calculation on the power transmission section to be subjected to power flow adjustment to obtain a power flow result of the power transmission section.
And 102, dividing a preset power grid into a transmitting end system and a receiving end system according to the active power flow direction at the power transmission section.
And step 103, determining the initial tidal current value of the power transmission section according to the tidal current values of all the branches.
And 104, determining a maximum voltage phase angle from the voltage phase angles of all the power generation nodes in the power station, and taking the power generation node corresponding to the maximum voltage phase angle as a representative node of the power station.
Step 105, determining a tide adjustment amount according to a preset target tide value and an initial tide value, and determining a transmitting end unit adjustment amount of a transmitting end system and a receiving end unit adjustment amount of a receiving end system according to the tide adjustment amount.
And 106, if the tide adjustment quantity is greater than zero, sequentially adjusting the active power output of each power generation node in the power generation station of the power transmission system according to the power transmission unit adjustment quantity, the active power output of each power generation node and the maximum active power output of each power generation node in the power transmission station of the power transmission system, and the order of the voltage phase angles of the representative nodes from large to small.
Step 107, according to the adjustment amount of the receiving end unit, the active power output of each generating node in the receiving end power station of the receiving end system and the maximum active power output of each generating node, sequentially adjusting the active power output of each receiving end power station according to the sequence of the voltage phase angle of the representative node from small to large.
And step 108, determining an updated tidal current value after the adjustment of the power transmission section tidal current according to the regulated active output of all the power stations.
And step 109, determining the tide deviation according to the target tide value and the updated tide value.
Step 110, if the power flow deviation is greater than or equal to the preset threshold, step 111 is executed: setting the updated tide value as an initial tide value, and returning to the step 105 of determining the tide adjustment quantity; and (3) ending the adjustment of the power flow of the power transmission section until the power flow deviation is smaller than a preset threshold value.
Specifically, in step 101, a power transmission section of which power flow is to be adjusted is determined according to needs, and a power flow result of the power transmission section includes a voltage phase angle of a power generation node, an active power output of the power generation node, and a current value of each branch in the power transmission section. Specifically, power flow calculation software, such as PDS-BPA software, can be used to calculate the power flow of the power transmission section, or the power flow of the power transmission section can be directly calculated by a formula, which is not particularly limited.
In step 102, the preset power grid represents a plurality of power transmission lines connected between two areas, the power transmission section of the power grid comprises a plurality of branches, the power grid comprises a plurality of power stations, and each power station comprises a plurality of power generation nodes. The power generation node corresponds to a power generating set in a power station, and refers to a node with an actual active output greater than zero or a maximum active output greater than zero, and a node with an actual active output equal to zero is also included in the embodiment of the present application, except for the balance node. That is, a generator set in a power plant represents a power generation node.
The power transmission section naturally divides the power grid into a transmitting end system and a receiving end system, as shown in fig. 2, which is a schematic structural diagram of the transmitting end system and the receiving end system provided by the embodiment of the application. The sending end system and the receiving end system are specifically divided in the following modes:
dividing a preset power grid into two systems at a power transmission section.
According to the active power flow direction, the system sending out power in the two systems is used as a sending end system, and the system flowing in power in the two systems is used as a receiving end system.
It should be noted that, the power station located in the power grid and the power station located in the power transmission system is the power transmission station, and the power station located in the power reception system is the power reception station.
In step 103, the sum of the tide values of all the branches is used as the initial tide value of the power transmission section.
In step 104, for each power plant, one or more power generation nodes are included in the power plant, each power generation node has a corresponding voltage phase angle, a maximum voltage phase angle is determined from the voltage phase angles of the power generation nodes, and the power generation node corresponding to the maximum voltage phase angle is taken as a representative node of the power plant. For all power stations in the power grid, a representative node for each power station is determined separately.
Therefore, by adopting the method, the influence of the power generation node on the stability of the power grid is reflected by the voltage phase angle of the power generation node, the power generation node which is least favorable for the stability of the power grid and the power generation node which is most favorable for the stability of the power grid are accurately judged, and a foundation is laid for the follow-up tide adjustment.
In step 105, the adjustment amount of the tide, the adjustment amount of the sending end unit and the adjustment amount of the receiving end unit are determined by the formula (1):
in the formula (1), delta P is the adjustment quantity of the tide, P 1 For the target tidal current value, P 0 For initial tidal current value, ΔP m For the adjustment of the end-feeding unit, ΔP n The adjustment amount is adjusted for the receiving end unit.
In step 106, the active power output of the power plant at the power plant end refers to the sum of the active power output of all the power generation nodes in the power plant at the power plant end. It should be noted that, the adjustment of the active output of the power station at the power transmitting end is to sequentially adjust the active output of each power generating node in each power station at the power transmitting end. Specifically, if the tidal current adjustment amount Δp is greater than zero, the active power output of each of the head-end power stations is sequentially adjusted by:
and sequencing all the sending-end power stations according to the sequence of the voltage phase angles of the representative nodes from large to small to obtain a sending-end power station sequence.
And determining an active adjustment value of the first power generation node according to the adjustment quantity of the power unit of the first power generation node in the first power generation station and the maximum active output of the first power generation node aiming at the first power generation station in the power generation station sequence of the first power generation station.
And if the active adjustment value of the first power generation node is not equal to the adjustment value of the power transmission unit, determining the active adjustment value of the next power generation node according to the first difference value between the adjustment value of the power transmission unit and the active adjustment value of the first power generation node, the active output of the next power generation node in the first power transmission station and the maximum active output of the next power generation node.
If the sum of the active adjustment values of all the power generation nodes in the first power generation station is not equal to the adjustment amount of the power generation unit, continuously determining the active adjustment value of each power generation node in the second power generation station in the power generation station sequence until the sum of the active adjustment values of all the power generation nodes adjusted in the power generation station sequence is equal to the adjustment amount of the power generation unit, and adjusting the active output of the corresponding power generation node according to the active adjustment value of each power generation node adjusted in the power generation station sequence.
In the process of adjusting the active output of the power generating nodes of the power transmitting end, if a plurality of power generating nodes exist in each power generating station of the power transmitting end, the adjusting sequence can be used for adjusting the active output of the power generating nodes of the power transmitting end according to the sequence from the high voltage phase angle to the low voltage phase angle.
In order to more clearly illustrate the active power output adjustment process for the power plant at the delivery end, the following description is given by way of example with reference to specific formulas.
Assuming that M transmitting power stations exist in the transmitting system, sequencing according to the sequence from big to small of the voltage phase angles of M representing nodes to obtain a transmitting power station sequence S m ＝{S m,1 ，S m,2 ……S m,M S, where S m,1 Is the sending end power station with the maximum voltage phase angle, S m,M Is a transmitting end power station with the minimum voltage phase angle. Assuming that k power generation nodes exist in each power generation station at the transmitting end, for each power generation station at the transmitting end in the power generation station sequence at the transmitting end, the power generation nodes are ordered according to the sequence from the high voltage phase angle to the low voltage phase angle, so that the whole power generation node sequence S= { S at the transmitting end can be obtained 1 ，S 2 ，S 3 ,……S Mk }。
For the first power generation node S 1 The deviation between the adjustable range and the adjustment amount of the sending end unit is determined by a formula (2):
ΔP 1 ＝ΔP m -(P max,1 -P 1 ) Formula (2)
In the formula (2), ΔP 1 For the deviation of the adjustable range of the first generating node and the adjustment quantity of the sending end unit, delta P m For adjusting the quantity of the end-feeding unit, P max,1 Maximum active output of first power generation node, P 1 Is the active force of the first power generation node.
If DeltaP 1 Less than or equal to zero, then P max,1 And delta P 1 And as a firstIndividual power generation nodes S 1 The adjusted target active value is subtracted by the active force P 1 The obtained difference is the active adjustment value delta P 1,1 According to the active regulation value, the first power generation node S in the first power station at the transmitting end is subjected to 1 After the active power output of the power station at the power delivery end is regulated, the active power regulation of the power station at the power delivery end is finished. The active regulation value of the first power generation node is equal to the regulation quantity of the power transmission unit, and the active output of the first power generation node is regulated to meet the regulation requirement of the power transmission flow, so that the active regulation of the power transmission station can be finished after the first power generation node is regulated.
If DeltaP 1 Greater than zero, P will max,1 As the first power generation node S 1 The adjusted target active value is subtracted by the active force P 1 The obtained difference is the active adjustment value delta P 1,1 For the first power generation node S 1 After the active output of the power generator is regulated, the second power generation node S is continuously regulated 2 Is an active force of the (c). It should be noted that, at this time, the active adjustment value of the first power generation node is not equal to the adjustment amount of the power transmission unit, which means that only the active output of the first power generation node is adjusted, so that the power transmission flow adjustment requirement cannot be met, and the next power generation node needs to be continuously adjusted after the adjustment of the first power generation node is completed.
And so on until the sum delta P of the active adjustment values of the first j power generation nodes in the power generation node sequence 1,1 +ΔP 1,2 +……ΔP 1,j Is equal to the adjustment quantity delta P of the end feeding unit m Wherein j is the number of power generation nodes at the transmitting end for active power regulation, and j is an integer which is more than or equal to 1 and less than or equal to Mk; mk is the total number of sender-side power nodes. And correspondingly adjusting the active output of each power generation node according to the active adjustment value of each power generation node, and ending the active adjustment of the power station at the power transmission end. It should be noted that, it is not necessary that each power generation node of each power generation in the power generation plant sequence at the transmitting end is adjusted, and the adjustment can be ended as long as the sum of the active adjustment values of the adjusted power generation nodes is equal to the adjustment amount of the power generation unit at the transmitting end.
In step 107, the active power output of the receiving power station refers to the sum of the active power output of all the power generation nodes in the receiving power station. It should be noted that, the adjustment of the active output of the receiving-end power station is to sequentially adjust the active output of each power generation node in each receiving-end power station. Specifically, if the tidal current adjustment amount Δp is greater than zero, the active power output of each of the receiving-side power stations is sequentially adjusted by:
and sequencing all the receiving end power stations according to the sequence of the voltage phase angles of the representative nodes from small to large to obtain a receiving end power station sequence.
And determining an active regulation value of the first receiving end power generation node according to the receiving end unit regulation quantity, the active power output of the first receiving end power generation node in the first receiving end power generation station and the maximum active power output of the first receiving end power generation node aiming at the first receiving end power generation station in the receiving end power generation station sequence.
And if the active adjustment value of the first receiving end power generation node is not equal to the receiving end unit adjustment value, determining the active adjustment value of the next power generation node according to the difference value between the receiving end unit adjustment value and the active adjustment value of the first receiving end power generation node, the active output of the next power generation node in the first receiving end power generation station and the maximum active output of the next power generation node.
And if the sum of the active adjustment values of all the power generation nodes in the first receiving-end power station is not equal to the adjustment quantity of the receiving-end unit, continuously determining the active adjustment value of each power generation node in the second receiving-end power station in the receiving-end power station sequence until the sum of the active adjustment values of all the power generation nodes adjusted in the receiving-end power station sequence is equal to the adjustment quantity of the receiving-end unit, and adjusting the active output of the corresponding power generation node according to the active adjustment value of each power generation node adjusted in the receiving-end power station sequence.
In the process of adjusting the active output of the receiving-end power generation node, if a plurality of power generation nodes exist in each receiving-end power generation station, the adjusting sequence can be used for adjusting the active output of the receiving-end power generation node according to the sequence from small voltage phase angles to large voltage phase angles.
In order to more clearly illustrate the active power output adjustment process for the receiving-side power station, the following description is given by way of example with reference to specific formulas.
The N receiving end power stations in the receiving end system are assumed to be arranged, and a receiving end power station sequence S is obtained after the sequence of the N receiving end power stations is ordered according to the sequence from small to large of the voltage phase angles of N representing nodes n ＝{S n,1 ，S n,2 ……S n,N S, where S n,1 Is the receiving end power station with the minimum voltage phase angle, S n,N Is the receiving end power station with the largest voltage phase angle. Assuming that t power generation nodes exist in each receiving-end power generation station, aiming at each receiving-end power generation station in the receiving-end power generation station sequence, the power generation nodes are ordered according to the order of the voltage phase angles from small to large, and then the whole receiving-end power generation node sequence S= { S can be obtained 1 ，S 2 ，S 3 ,……S Nt }。
For the first power generation node S 1 The deviation between the adjustable range and the adjustment amount of the receiving end unit is determined by a formula (3):
ΔP 1 ＝ΔP n +P 1 formula (3)
In the formula (3), ΔP 1 For the deviation of the adjustable range of the first generating node and the adjustment quantity of the receiving end unit, delta P n For the adjustment of the receiving end unit, P 1 Is the active force of the first power generation node.
If DeltaP 1 Greater than or equal to zero, ΔP will be 1 As the first power generation node S 1 The adjusted target active value is subtracted by the active force P 1 The obtained difference is the active adjustment value delta P 1,1 According to the active regulation value, for the first power generation node S 1 After the active power output of the receiving end power station is regulated, the active power regulation of the receiving end power station is finished. The active power adjusting value of the first power generation node is equal to the adjusting quantity of the receiving end unit, and the active power output of the first power generation node is adjusted to meet the receiving end tide adjusting requirement, so that the active power adjustment of the receiving end power station can be finished after the first power generation node is adjusted.
If DeltaP 1 Less than zero, zero is taken as the first power generation node S 1 The adjusted target active value is subtracted from the target active valueActive force P 1 The obtained difference is the active adjustment value delta P 1,1 For the first power generation node S 1 After the active output of the power generator is regulated, the second power generation node S is continuously regulated 2 Is an active force of the (c). It should be noted that, at this time, the active adjustment value of the first power generation node is not equal to the adjustment amount of the receiving end unit, which means that only the active output force of the first power generation node is adjusted, so that the requirement of receiving end tide adjustment cannot be met, and the next power generation node needs to be continuously adjusted after the first power generation node is adjusted.
And so on until the sum delta P of the active adjustment values of all the power generation nodes 1,1 +ΔP 1,2 +……ΔP 1,i Is equal to the adjustment quantity delta P of the receiving end unit n Wherein i is the number of receiving end power generation nodes for active power regulation, i is an integer greater than or equal to 1 and less than or equal to Nt; nt is the total number of receiving end power generation nodes. And correspondingly adjusting the active output of each power generation node according to the active adjustment value of each power generation node, and ending the active adjustment of the receiving end power station. It should be noted that, not every power generation node of every power generation in the receiving end power generation station sequence is necessarily adjusted, and the adjustment can be ended as long as the sum of the active adjustment values of the adjusted power generation nodes is equal to the adjustment amount of the receiving end unit.
Before performing step 108, the following steps are also performed:
if the tide adjustment quantity is smaller than zero, the active power output of each power generation node and the maximum active power output of each power generation node in the power generation station of the power transmission system are sequentially adjusted according to the adjustment quantity of the power transmission unit, the active power output of each power generation node and the sequence from small to large of the voltage phase angle of the representative node. The active output of the power station at the power transmission end is the sum of the active outputs of all power generation nodes in the power station at the power transmission end.
And according to the adjustment quantity of the receiving end unit, the active power output of each power generation node in the receiving end power station of the receiving end system and the maximum active power output of each power generation node, sequentially adjusting the active power output of each receiving end power station according to the sequence of the voltage phase angles of the representative nodes from large to small. The active output of the receiving end power station is the sum of the active outputs of all power generation nodes in the receiving end power station.
Specifically, when the power flow adjustment amount Δp is smaller than zero, the power transmission unit adjustment amount is also smaller than zero, the active processing adjustment process of the receiving power station can be referred to when the power flow adjustment amount Δp is larger than zero, so as to adjust the active output of the power transmission station when the power flow adjustment amount Δp is smaller than zero, that is, refer to formula (3), until the sum of the active adjustment values of the first j power generation nodes of the power transmission station is equal to the power transmission unit adjustment amount, and the power transmission is ended. Wherein j is an integer greater than or equal to 1 and less than or equal to Mk; mk is the total number of sender-side power nodes.
When the power flow adjustment amount Δp is smaller than zero, the adjustment amount of the receiving end unit is larger than zero, and the active power processing adjustment process of the sending end power station can be referred to when the power flow adjustment amount Δp is larger than zero, so that the active power output of the receiving end power station when the power flow adjustment amount Δp is smaller than zero can be adjusted, namely, the formula (2) is referred to until the sum of the active adjustment values of the first i power generation nodes of the receiving end power station is equal to the adjustment amount of the receiving end unit, and the receiving end power flow adjustment is finished. Wherein i is an integer greater than or equal to 1 and less than or equal to Nt; nt is the total number of receiving end power generation nodes.
By adopting the method for power flow adjustment, when the section power flow needs to be increased, the power generation nodes of the transmitting end, which are unfavorable for power grid stability, can be preferentially increased, the power generation nodes of the receiving end, which are favorable for power grid stability, can be preferentially reduced, when the section power flow needs to be reduced, the power generation nodes of the transmitting end, which are favorable for power grid stability, can be preferentially increased, and further, the power flow adjustment is carried out in the direction which is least favorable for power grid stability. The tide adjusting method can ensure that the minimum, namely the most conservative section limit is obtained, and is more beneficial to the safety and stability of the power grid.
In step 108, according to the regulated active power output of all the power stations, carrying out load flow calculation on the power transmission section again to obtain an updated current value after the load flow adjustment of the power transmission section.
In step 109, the power flow deviation is determined by formula (4):
ΔP'＝P 1 -P' 0 formula (4)
In the formula (4), deltaP' is the power flow deviation, P 1 For the target tidal current value, P' 0 To update the tidal current value.
In step 110 and step 111, it is determined whether the power flow deviation Δp 'is smaller than a preset threshold, and if the power flow deviation Δp' is greater than or equal to the preset threshold, the current value P 'is updated' 0 Setting the current value as an initial current value, returning to the step 105 of determining the current adjustment quantity, carrying out current adjustment again, and calculating the current deviation again until the current deviation is smaller than a preset threshold value, and ending the current adjustment on the power transmission section.
In order to more clearly illustrate steps 101 to 111, the following description is given by way of specific examples.
The preset power system provided by the embodiment of the application is simulated by adopting PDS-BPA software, the preset power transmission section divides the preset power system into a power transmission end system and a power receiving end system according to the active power flow direction, two branches are arranged at the power transmission section, namely a branch 1 and a branch 2, the power transmission end system comprises a power supply A, a power supply B and a power supply C, 2X 177.3= 354.6MW of power is transmitted to the power receiving end system through the two branches, and the power receiving end system comprises a power supply D and a power supply E. The power supply A comprises two power generation nodes, namely A1G and A2G; the power supply B comprises two power generation nodes, namely B1G and B2G; the power supply C comprises two power generation nodes, namely C1G and C2G; the power supply D comprises two power generation nodes, namely D1G and D2G, and D1G is a balancing machine; the power supply E includes a power generation node, E1G. The maximum active power output of each power generation node in the power source A, the power source B, the power source C, the power source E and the power source D is 80MW.
In order to calculate the limit of two branches N-1 (1 loop out) of the preset power system at the transmission section, it is necessary to increase the power flow to 410MW. That is, the initial tidal current value P0 is 354.6MW, the target tidal current value P 1 For 410MW, the tidal current adjustment amount Δp is 410MW-354.6 mw=55.4 MW.
The power flow calculation is performed on a preset power system, and the power generation nodes, the active power output of each power generation node and the voltage phase angle information of each power generation node in each power generation station of the power system are shown in table 1.
Table 1: power generation node and one example of active output and voltage phase angle of power generation node in each power station of power system
In the power station A, the voltage phase angle of the power supply A1G is the largest, the power supply A1G is a representative node of the power station A, and the power supply B1G is a representative node of the power station B, the power supply C1G is a representative node of the power station C, the power supply D2G is a representative node of the power station D, and the power supply E1G is a representative node of the power station E.
According to the tide adjustment quantity delta P=55.4MW, determining the adjustment quantity delta P of the sending end unit m 55.4MW, receiver unit adjustment ΔP n Is-55.4 MW. Since the tidal current adjustment amount Δp=55.4 MW>And 0, adjusting the active output of the corresponding power stations according to the active output adjusting process of the power station at the transmitting end and the power station at the receiving end when the tide adjusting quantity delta P is larger than zero. The specific process is as follows:
sequencing the power stations at the transmitting end from large to small according to the voltage phase angles of the representative nodes, and sequencing the power stations at the transmitting end in a sequence S m = { power supply B, power supply C, power supply a }; the receiving end power stations are ordered according to the voltage phase angles of the representative nodes from small to large, and the receiving end power station sequences S n = { power D, power E }. The power generation node sequence of the transmitting end= { power B1G, power B2G, power C1G, power C2G, power A1G, power A2G }, and the power generation node sequence of the receiving end= { power D1G, power D2G, power E1G, }.
For the first power generation node B1G of the power station at the transmitting end, the power is fully output and cannot be up-regulated.
For the second power generation node B2G of the power station at the transmitting end, the deviation delta P of the adjustable range and the adjustment quantity of the unit at the transmitting end 2 ＝55.4-(80-50)＝25.4>And 0, taking 80MW as a target active value of the second power generation node B2G, wherein the active adjustment value is 80-50=30MW, namely the active force of the B2G is up-regulated by 30MW, and the original 50MW is up-regulated to 80MW.
For the third power generation node C1G of the power station at the transmitting end, the power is fully output and cannot be up-regulated.
For a fourth power generation node C2G of the power station at the transmitting end, the deviation delta P of the adjustable range and the adjustment quantity of the unit at the transmitting end 4 ＝25.4-(80-0)＝-54.6<And 0, taking 80-54.6=25.4MW as a target active value of a fourth power generation node C2G, namely, up-regulating the active output of the C2G by 25.4MW, and ending the active regulation of the power station at the transmitting end.
The first power generation node D1G of the receiving-end power station is a balancing machine and is not considered. For the second power generation node D2G of the receiving end power station, the deviation delta P of the adjustable range and the adjustment quantity of the receiving end unit 2 ＝-55.4+50＝-5.4<00, taking 0MW as a target active value of the second power generation node D2G, wherein the active adjustment value is 0-50= -50MW, namely, the active output of the D2G is adjusted down by 50MW, the original 50MW is adjusted to 0MW, and the active output of the third power generation node E1G of the receiving end power station needs to be continuously adjusted at the moment.
For the third power generation node E1G of the receiving end power station, the deviation delta P of the adjustable range and the adjustment quantity of the receiving end unit 3 ＝-5.4+50＝44.6>And 0, taking 44.6MW as a target active value of the third power generation node E1G, wherein the active adjustment value is 44.6-50= -5.4MW, namely, the active force of E1G is adjusted down by 5.4MW, the original 50MW is adjusted to 44.6MW, and the active adjustment of the receiving end power station is finished.
According to the active power output adjusted by each power generation node, the power flow of the power transmission section is recalculated, the updated current value is 408.3MW, the power flow deviation is 410MW-408.3 MW=1.7MW, and the absolute value is larger than the preset threshold value of 1MW, so that the power flow adjustment is needed again. And repeating the calculation of the steps, and finally adjusting the active output from 25.4W to 27.1MW for the fourth generation node C2G of the power station at the transmitting end and adjusting the active output from 44.6MW to 42.9MW for the second generation node D2G of the power station at the receiving end.
And (3) re-calculating the power flow of the power transmission section according to the regulated active power output to obtain an updated current value of 410MW, wherein the power flow deviation is 410MW-410 MW=0 MW, the absolute value is smaller than a preset threshold value of 1MW, and the power flow regulation is finished.
The following are examples of the apparatus of the present application that may be used to perform the method embodiments of the present application. For details not disclosed in the embodiments of the apparatus of the present application, please refer to the embodiments of the method of the present application.
Fig. 3 is a schematic structural diagram of a power transmission section power flow adjustment device of a power system according to an embodiment of the present application. As shown in fig. 3, the device has a function of implementing the method for adjusting the power transmission section tide of the power system, and the function can be implemented by hardware or by executing corresponding software by hardware. The apparatus may include: a preprocessing unit 301, a processing unit 302, a first adjusting unit 303, and a verification unit 304.
The preprocessing unit 301 is configured to perform power flow calculation on a power transmission section to be subjected to power flow adjustment, so as to obtain a power flow result of the power transmission section; the tide results comprise the voltage phase angle of the power generation node, the active power output of the power generation node and the tide value of each branch in the power transmission section; dividing a preset power grid into a transmitting end system and a receiving end system according to the active power flow direction at a power transmission section; the power transmission section comprises a plurality of branches; the power grid comprises a plurality of power stations; the power plant comprises a plurality of power generation nodes; the method comprises the steps of carrying out a first treatment on the surface of the And determining the initial tidal current value of the power transmission section according to the tidal current values of all the branches.
The processing unit 302 is configured to determine a maximum voltage phase angle from voltage phase angles of all power generation nodes in the power station, and use a power generation node corresponding to the maximum voltage phase angle as a representative node of the power station; and determining a tide adjustment amount according to the preset target tide value and the initial tide value, and determining a transmitting end unit adjustment amount of the transmitting end system and a receiving end unit adjustment amount of the receiving end system according to the tide adjustment amount.
A first adjusting unit 303, configured to sequentially adjust the active power output of each power generating station at the power transmitting end according to the power transmitting end unit adjustment amount, the active power output of each power generating node in the power transmitting end generating station at the power transmitting end system, and the maximum active power output of each power generating node, in order from the high phase angle of the voltage representing the node to the low phase angle of the voltage representing the node, if the power flow adjustment amount is greater than zero; the active output of the power station at the power transmission end is the sum of the active outputs of all power generation nodes in the power station at the power transmission end; according to the adjustment quantity of the receiving end unit, the active power output of each generating node in the receiving end power station of the receiving end system and the maximum active power output of each generating node, the active power output of each receiving end power station is sequentially adjusted according to the sequence that the voltage phase angles of the representative nodes are from small to large; the active output of the receiving-end power station is the sum of the active outputs of all the power generation nodes in the receiving-end power station.
The verification unit 304 is used for determining an updated current value after the power transmission section tide adjustment according to the active power output after all power stations are adjusted; determining a tide deviation according to the target tide value and the updated tide value; and if the power flow deviation is greater than or equal to a preset threshold value, setting the updated power flow value as an initial current value, and returning to the step of determining the power flow adjustment amount until the power flow deviation is less than the preset threshold value, and ending the power flow adjustment of the power transmission section.
In one implementation, the preprocessing unit 301 is specifically configured to:
dividing a preset power grid into two systems at a power transmission section.
According to the active power flow direction, the system sending out power in the two systems is used as a sending end system, and the system flowing in power in the two systems is used as a receiving end system.
In one implementation, the tidal current adjustment, the sending end unit adjustment, and the receiving end unit adjustment are determined by:
wherein ΔP is the flow adjustment amount, P 1 For the target tidal current value, P 0 For initial tidal current value, ΔP m For the adjustment of the end-feeding unit, ΔP n The adjustment amount is adjusted for the receiving end unit.
In one implementation, the first adjusting unit 303 is specifically configured to:
and sequencing all the sending-end power stations according to the sequence of the voltage phase angles of the representative nodes from large to small to obtain a sending-end power station sequence.
And determining an active adjustment value of the first power generation node according to the adjustment quantity of the power unit of the first power generation node in the first power generation station and the maximum active output of the first power generation node aiming at the first power generation station in the power generation station sequence of the first power generation station.
And if the active adjustment value of the first power generation node is not equal to the adjustment value of the power transmission unit, determining the active adjustment value of the next power generation node according to the first difference value between the adjustment value of the power transmission unit and the active adjustment value of the first power generation node, the active output of the next power generation node in the first power transmission station and the maximum active output of the next power generation node.
If the sum of the active adjustment values of all the power generation nodes in the first power generation station is not equal to the adjustment amount of the power generation unit, continuously determining the active adjustment value of each power generation node in the second power generation station in the power generation station sequence until the sum of the active adjustment values of all the power generation nodes adjusted in the power generation station sequence is equal to the adjustment amount of the power generation unit, and adjusting the active output of the corresponding power generation node according to the active adjustment value of each power generation node adjusted in the power generation station sequence.
In one implementation, the first adjusting unit 303 is specifically configured to:
sequencing all receiving end power stations according to the sequence of the voltage phase angles of the representative nodes from small to large to obtain a receiving end power station sequence;
determining an active adjustment value of a first receiving end power generation node according to the adjustment amount of the receiving end unit, the active power output of the first receiving end power generation node in the first receiving end power generation station and the maximum active power output of the first receiving end power generation node aiming at the first receiving end power generation station in the receiving end power generation station sequence;
if the active adjustment value of the first receiving end power generation node is not equal to the receiving end unit adjustment value, determining the active adjustment value of the next power generation node according to the difference value between the receiving end unit adjustment value and the active adjustment value of the first receiving end power generation node, the active output of the next power generation node in the first receiving end power generation station and the maximum active output of the next power generation node;
and if the sum of the active adjustment values of all the power generation nodes in the first receiving-end power station is not equal to the adjustment quantity of the receiving-end unit, continuously determining the active adjustment value of each power generation node in the second receiving-end power station in the receiving-end power station sequence until the sum of the active adjustment values of all the power generation nodes adjusted in the receiving-end power station sequence is equal to the adjustment quantity of the receiving-end unit, and adjusting the active output of the corresponding power generation node according to the active adjustment value of each power generation node adjusted in the receiving-end power station sequence.
In one implementation, the apparatus further comprises:
the second adjusting unit is used for adjusting the active power output of each power generating node in the power generating station of the power transmitting system according to the adjustment amount of the power transmitting unit, the active power output of each power generating node and the maximum active power output of each power generating node in sequence from small to large according to the voltage phase angle of the representative node if the adjustment amount of the power flow is smaller than zero; the active output of the power station at the power transmission end is the sum of the active outputs of all power generation nodes in the power station at the power transmission end;
according to the adjustment quantity of the receiving end unit, the active power output of each power generation node in the receiving end power station of the receiving end system and the maximum active power output of each power generation node, sequentially adjusting the active power output of each receiving end power station according to the sequence of the voltage phase angles of the representative nodes from large to small; the active output of the receiving-end power station is the sum of the active outputs of all the power generation nodes in the receiving-end power station.
In this way, the embodiment of the application reflects the influence of the power generation node on the stability of the power grid through the voltage phase angle of the power generation node in the power grid, takes the power generation node with the largest voltage phase angle in each power station as the representative node of the power station, sorts the power stations according to the voltage phase angles of the representative nodes, and sequentially adjusts the active output of the power stations according to the order which is least favorable for the stability of the power grid, namely, carries out tide adjustment. The tide adjusting method can ensure that the minimum, namely the most conservative section limit is obtained, and is more beneficial to the safety and stability of the power grid.
In an exemplary embodiment, there is also provided a computer-readable storage medium having stored therein a computer program or a smart contract that is loaded and executed by a node to implement the transaction method provided by the above embodiment. Alternatively, the above-mentioned computer readable storage medium may be a Read-Only Memory (ROM), a random-access Memory (RandomAccess Memory, RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, or the like.
It will be apparent to those skilled in the art that the techniques of embodiments of the present application may be implemented in software plus a necessary general purpose hardware platform. Based on such understanding, the technical solutions in the embodiments of the present application may be embodied in essence or what contributes to the prior art in the form of a software product, which may be stored in a storage medium, such as a ROM/RAM, a magnetic disk, an optical disk, etc., including several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the method described in the embodiments or some parts of the embodiments of the present application.
Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any adaptations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.
It is to be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, and that various modifications and changes may be effected without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims (5)

1. A method for adjusting a power transmission section power flow of an electric power system, the method comprising:
carrying out power flow calculation on a power transmission section to be subjected to power flow adjustment to obtain a power flow result of the power transmission section; the tide results comprise a voltage phase angle of the power generation node, active power output of the power generation node and tide values of all branches in the power transmission section;
dividing a preset power grid into a transmitting end system and a receiving end system according to the active power flow direction at the power transmission section; the power transmission section comprises a plurality of branches; the power grid comprises a plurality of power stations; the power plant comprises a plurality of power generation nodes;
Determining an initial tidal current value of the power transmission section according to the tidal current values of all the branches;
determining a maximum voltage phase angle from the voltage phase angles of all the power generation nodes in the power station, and taking the power generation node corresponding to the maximum voltage phase angle as a representative node of the power station;
determining a tide adjustment amount according to a preset target tide value and the initial tide value, and determining a transmitting end unit adjustment amount of a transmitting end system and a receiving end unit adjustment amount of a receiving end system according to the tide adjustment amount;
the tide adjustment amount, the sending end unit adjustment amount and the receiving end unit adjustment amount are determined by the following modes:
；
wherein ΔP is the flow adjustment amount, P 1 For the target tidal current value, P 0 For the initial tidal current value, ΔP m For the adjustment of the sending end unit, delta P n Adjusting the quantity for the receiving end unit;
if the tide adjustment quantity is larger than zero, according to the tide adjustment quantity of the transmitting end unit, the active power output of each generating node and the maximum active power output of each generating node in the transmitting end power station of the transmitting end system, the active power output of each transmitting end power station is sequentially adjusted according to the sequence from large to small of the voltage phase angle of the representative node, and the active power output of each transmitting end power station is sequentially adjusted by the following steps: sequencing all the sending-end power stations according to the sequence of the voltage phase angles of the representative nodes from large to small to obtain a sending-end power station sequence;
Determining an active adjustment value of a first power generation node according to the adjustment amount of the power unit of the first power generation end, the active output of the first power generation node in the first power generation end and the maximum active output of the first power generation node aiming at the first power generation end in the power generation end sequence;
if the active adjustment value of the first power generation node is not equal to the power transmission unit adjustment value, determining the active adjustment value of the next power generation node according to a first difference value between the power transmission unit adjustment value and the active adjustment value of the first power generation node, the active output of the next power generation node in the first power transmission station and the maximum active output of the next power generation node;
if the sum of the active adjustment values of all the power generation nodes in the first power generation station is not equal to the power generation unit adjustment amount, continuously determining the active adjustment value of each power generation node in the second power generation station in the power generation station sequence until the sum of the active adjustment values of all the power generation nodes adjusted in the power generation station sequence is equal to the power generation unit adjustment amount, and adjusting the active output of the corresponding power generation node according to the active adjustment value of each power generation node adjusted in the power generation station sequence;
The active output of the power station at the power transmitting end is the sum of the active outputs of all power generating nodes in the power station at the power transmitting end;
according to the adjustment quantity of the receiving end unit, the active power output of each power generation node and the maximum active power output of each power generation node in the receiving end power station of the receiving end system, the active power output of each receiving end power station is sequentially adjusted according to the sequence of the voltage phase angle of the representative node from small to large, and the active power output of each receiving end power station is sequentially adjusted by the following modes:
sequencing all receiving end power stations according to the sequence of the voltage phase angles of the representative nodes from small to large to obtain a receiving end power station sequence;
determining an active regulation value of a first receiving end power generation node according to the receiving end unit regulation quantity, the active power output of the first receiving end power generation node in the first receiving end power generation station and the maximum active power output of the first receiving end power generation node aiming at the first receiving end power generation station in the receiving end power generation station sequence;
if the active adjustment value of the first receiving end power generation node is not equal to the receiving end unit adjustment value, determining the active adjustment value of the next power generation node according to the difference value between the receiving end unit adjustment value and the active adjustment value of the first receiving end power generation node, the active output of the next power generation node in the first receiving end power generation station and the maximum active output of the next power generation node;
If the sum of the active adjustment values of all the power generation nodes in the first receiving-end power station is not equal to the receiving-end unit adjustment amount, continuously determining the active adjustment value of each power generation node in the second receiving-end power station in the receiving-end power station sequence until the sum of the active adjustment values of all the power generation nodes adjusted in the receiving-end power station sequence is equal to the receiving-end unit adjustment amount, and adjusting the active output of the corresponding power generation node according to the active adjustment value of each power generation node adjusted in the receiving-end power station sequence;
the active output of the receiving end power station is the sum of the active outputs of all power generation nodes in the receiving end power station;
according to the active power output adjusted by all power stations, determining an updated tidal current value after the power flow adjustment of the power transmission section;
determining a power flow deviation according to the target tide value and the updated power flow value;
if the power flow deviation is larger than or equal to a preset threshold value, setting the updated power flow value as an initial power flow value, and returning to the step of determining the power flow adjustment amount until the power flow deviation is smaller than the preset threshold value, and ending the power flow adjustment of the power transmission section;
If the tide adjustment quantity is smaller than zero, sequentially adjusting the active power output of each power generation node in the power generation station of the power transmission system according to the tide adjustment quantity of the power transmission unit, the active power output of each power generation node and the maximum active power output of each power generation node in the power generation station of the power transmission system from small to large according to the voltage phase angle of the representative node;
and according to the adjustment quantity of the receiving end unit, the active power output of each power generation node and the maximum active power output of each power generation node in the receiving end power station of the receiving end system, sequentially adjusting the active power output of each receiving end power station according to the sequence of the voltage phase angle of the representative node from large to small.
2. The method according to claim 1, wherein the dividing the preset power grid into a transmitting end system and a receiving end system according to the active power flow direction at the power transmission section comprises:
dividing a preset power grid into two systems at the power transmission section;
and taking the system for sending out power in the two systems as a transmitting end system and the system for flowing in power in the two systems as a receiving end system according to the active power flow direction.
3. A power transmission section power flow adjustment device for a power system based on the power transmission section power flow adjustment method for a power system according to claim 1, characterized in that the device comprises:
The preprocessing unit is used for carrying out power flow calculation on the power transmission section to be subjected to power flow adjustment to obtain a power flow result of the power transmission section; the tide results comprise a voltage phase angle of the power generation node, active power output of the power generation node and tide values of all branches in the power transmission section; dividing a preset power grid into a transmitting end system and a receiving end system according to the active power flow direction at the power transmission section; the power transmission section comprises a plurality of branches; the power grid comprises a plurality of power stations; the power plant comprises a plurality of power generation nodes; determining an initial tidal current value of the power transmission section according to the tidal current values of all the branches;
the processing unit is used for determining a maximum voltage phase angle from the voltage phase angles of all the power generation nodes in the power station, and taking the power generation node corresponding to the maximum voltage phase angle as a representative node of the power station; determining a tide adjustment amount according to a preset target tide value and the initial tide value, and determining a transmitting end unit adjustment amount of a transmitting end system and a receiving end unit adjustment amount of a receiving end system according to the tide adjustment amount;
the first adjusting unit is used for adjusting the active power output of each power generation node in the power generation station of the power transmission system according to the power transmission unit adjusting amount, the active power output of each power generation node and the maximum active power output of each power generation node in sequence from large to small according to the voltage phase angle of the representative node if the power flow adjusting amount is larger than zero;
The active output of the power station at the power transmitting end is the sum of the active outputs of all power generating nodes in the power station at the power transmitting end; according to the adjustment quantity of the receiving end unit, the active power output of each power generation node and the maximum active power output of each power generation node in the receiving end power station of the receiving end system, the active power output of each receiving end power station is sequentially adjusted according to the sequence of the voltage phase angles of the representative nodes from small to large; the active output of the receiving end power station is the sum of the active outputs of all power generation nodes in the receiving end power station;
the verification unit is used for determining an updated current value after the power transmission section tide adjustment according to the active power output after all power stations are adjusted; and determining a power flow deviation from the target tidal current value and the updated power flow value; and if the power flow deviation is greater than or equal to a preset threshold value, setting the updated power flow value as an initial power flow value, and returning to the step of determining the power flow adjustment amount until the power flow deviation is less than the preset threshold value, and ending the power flow adjustment of the power transmission section.
4. A device according to claim 3, characterized in that the preprocessing unit is specifically configured to:
Dividing a preset power grid into two systems at the power transmission section;
and taking the system for sending out power in the two systems as a transmitting end system and the system for flowing in power in the two systems as a receiving end system according to the active power flow direction.
5. A device according to claim 3, characterized in that the device further comprises:
the second adjusting unit is used for adjusting the active power output of each power generation node in the power generation station of the power transmission system according to the power transmission unit adjusting amount, the active power output of each power generation node and the maximum active power output of each power generation node in sequence from small to large according to the voltage phase angle of the representative node if the power flow adjusting amount is smaller than zero; the active output of the power station at the power transmitting end is the sum of the active outputs of all power generating nodes in the power station at the power transmitting end; according to the adjustment quantity of the receiving end unit, the active power output of each power generation node and the maximum active power output of each power generation node in the receiving end power station of the receiving end system, the active power output of each receiving end power station is sequentially adjusted according to the sequence of the voltage phase angles of the representative nodes from large to small; the active output of the receiving end power station is the sum of the active outputs of all power generation nodes in the receiving end power station.
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