A multi-time scale coordinated reactive power and voltage optimization control method and system

Abstract

The application discloses a multi-time scale coordinated reactive power voltage optimization control method and system. In the day-ahead time scale, the discrete reactive power source action plan of the day-ahead section is determined according to the active power load prediction information of the power grid load node, the active power output prediction information of the new energy node and the new energy node power generation plan information; in the intra-day time scale, the voltage correction limit value of the power grid calculation node is solved according to the active power load prediction information of the power grid load node and the active power output prediction information of the new energy node; in the real-time scale, the regional reactive power voltage decision is made according to the discrete reactive power source action plan of the day-ahead and the voltage correction limit value of the intra-day power grid calculation node. The application optimizes the reactive power strategy as a whole in the multi-time continuous section, solves the optimization coordination of multiple resources, optimizes the equipment decision, reduces the action times of the discrete reactive power source and improves the ability of the power grid to resist potential risks.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power system operation and control, and particularly relates to a multi-time scale coordinated reactive power voltage optimization control method and system. BACKGROUND

[0002] The reactive power voltage control application is an important technical means for dispatch to realize the safety control and management of the reactive power voltage of the power grid, and with the large-scale grid connection of new energy, the randomness and volatility of the new energy bring great influence to the voltage of the power grid, and the current single-section three-level voltage control decision cannot meet the voltage control demand of the new power system, and the decision of the reactive power resource needs to be optimized from the long time scale, so as to meet the safety and optimization demand of the reactive power regulation of the power grid in the long time scale. SUMMARY

[0003] The present application aims to provide a multi-time scale coordinated reactive power voltage optimization control method and system to solve the problem of the reactive power voltage control decision of the new power system with large-scale grid connection of new energy in the long time scale.

[0004] In order to achieve the above-mentioned target, the present application adopts the following technical scheme:

[0005] In the first aspect, a multi-time scale coordinated reactive power voltage optimization control method comprises:

[0006] In the day-ahead time scale, the discrete reactive power source action plan of the day-ahead section is determined according to the active power load prediction information of the power grid load node, the active power output prediction information of the new energy node and the power generation plan information of the new energy node;

[0007] In the intra-day time scale, the voltage correction limit value of the power grid calculation node is solved according to the active power load prediction information of the power grid load node and the active power output prediction information of the new energy node in the intra-day section;

[0008] In the real-time scale, the regional reactive power voltage decision is made according to the discrete reactive power source action plan of the day-ahead and the voltage correction limit value of the intra-day power grid calculation node.

[0009] Further, the discrete reactive power source action plan of the day-ahead section is determined according to the active power load prediction information of the power grid load node, the active power output prediction information of the new energy node and the power generation plan information of the new energy node in the day-ahead time scale, comprising:

[0010] The voltage deviation of the power grid calculation node in the day-ahead continuous section is calculated according to the active power load of the power grid load node, the active power output of the new energy node and the active power plan of the new energy node in the day-ahead section;

[0011] According to the voltage deviation of the power grid calculation node in the day-ahead continuous section, the voltage value of the power grid calculation node in each day-ahead section is calculated;

[0012] According to the voltage value change rule of the day-ahead section power grid calculation node, whether the day-ahead section needs to increase the discrete reactive power source action plan is evaluated, and the discrete reactive power source action plan is formulated.

[0013] Further, the voltage deviation of the power grid calculation node in the day-ahead continuous section is calculated according to the following formula:

[0014]

[0015] In the formula, i is the node number of the power grid, and n d is the maximum node number of the power grid; t and t-1 are the section numbers of the day-ahead section; j is the load number, n ld is the maximum load node number of the power grid; k is the new energy number, n g is the maximum new energy node number of the power grid; ΔV i,t is the voltage deviation of the i th node in the t th day-ahead section relative to the previous day-ahead section; V i,t and V i,t-1 are the voltage values of the i th calculation node in the t th and t-1 th day-ahead sections respectively; is the active power of the j th load node in the t th day-ahead section to the i th node voltage-active power sensitivity; and P are the active power loads of the j th load node in the t th and t-1 th day-ahead sections respectively; is the active power of the k th new energy node in the t th day-ahead section to the i th node voltage-active power sensitivity; and P are the active power outputs of the k th new energy node in the t th and t-1 th day-ahead sections respectively;

[0016] Further, the voltage value of the power grid calculation node in each day-ahead section is calculated according to the following formula:

[0017]

[0018] In the formula, i is the node number of the power grid; t and t-1 are the section numbers of the day-ahead section; m is the section number of the day-ahead section; V i,t , V i,t-1 , V i,0 are the voltage values of the i th calculation node in the t th, t-1 th and 0 th day-ahead sections respectively, and ΔV i,tThe voltage deviation of the ith node in the tth day-ahead section relative to the previous day-ahead section.

[0019] Further, the voltage value change rule of the grid calculation node according to the day-ahead section is used to evaluate whether the day-ahead section needs to increase the discrete reactive power source action plan, comprising:

[0020] If the voltage value of the grid calculation node of the day-ahead section meets Or V i,t ,the discrete reactive power source action plan is increased; V i,t

[0021] If the voltage value of the grid calculation node of the day-ahead section meets The discrete reactive power source action plan is not increased;

[0022] Wherein, i is the grid calculation node serial number; V i,t , V i,t The voltage value, the upper limit of voltage and the lower limit of voltage of the ith calculation node in the tth day-ahead section are respectively.

[0023] Further, after judging that the day-ahead section needs to increase the discrete reactive power source action plan, the voltage deviation of the grid calculation node of the tth day-ahead section and the subsequent day-ahead sections is corrected by the following formula: m

[0024]

[0025] In the formula, i is the grid calculation node serial number; t is the day-ahead section serial number; t m is the calculation day-ahead section serial number, and the section has a discrete reactive power source action plan; p is the discrete reactive power source action serial number, n C is the total number of discrete reactive power sources planned to act at t time; ΔV i,t is the voltage deviation of the ith node in the tth day-ahead section relative to the previous day-ahead section. is the voltage influence on the ith calculation node after the discrete reactive power source action of the tth day-ahead section; is the voltage-reactive power sensitivity of the pth discrete reactive power source of the tth day-ahead section to the ith node; ΔQ t,p is the grid reactive power injection after the pth discrete reactive power source action of the tth day-ahead section.

[0026] Further, in the intraday time scale, the grid calculation node voltage correction limit value is solved according to the intraday section grid load node active load prediction information and the new energy node active output prediction information, comprising:

[0027] ​According to the active load of the power grid load node and the active output of the new energy node in the daily section, the voltage deviation of the power grid calculation node in the daily continuous section is calculated;

[0028] According to the voltage deviation of the power grid calculation node in the daily continuous section, the voltage deviation of the power grid calculation node in the daily section relative to the original initial section is calculated, and according to the direction of the voltage deviation of the power grid calculation node in the daily section relative to the original initial section, it is judged that the voltage deviation of the power grid calculation node in the daily section relative to the original initial section is an upper voltage deviation or a lower voltage deviation;

[0029] According to the upper voltage deviation or the lower voltage deviation of the power grid calculation node in the daily section relative to the original initial section, the upper and lower limits of the voltage of the power grid calculation node are corrected.

[0030] Further, the voltage deviation of the power grid calculation node in the daily continuous section is calculated according to the following formula:

[0031]

[0032] In the formula, i is the node number of the power grid, and n d is the maximum node number of the power grid; t in and t in -1 are the section numbers in a day; j is the load number, n ld is the maximum load number of the power grid; k is the new energy number, n g is the maximum new energy node number of the power grid; is the voltage deviation of the i th node in the t th daily section relative to the previous daily section; and are the voltage values of the i th calculation node in the t in th and t in -1 daily section, respectively; is the active power of the j th load node in the t in th daily section to the voltage-active power sensitivity of the i th node; are the active loads of the j th load node in the t in th and t in -1 daily section, respectively; is the active power of the k th new energy node in the t in th daily section to the voltage-active power sensitivity of the i th node; are the active outputs of the k th new energy node in the t in th and t in -1 daily section, respectively.

[0033] Further, according to the direction of the voltage deviation of the power grid calculation node in the daily section relative to the original initial section, it is judged that the voltage deviation of the power grid calculation node in the daily section relative to the original initial section is an upper voltage deviation or a lower voltage deviation, which comprises:

[0034] If the voltage deviation of the intra-day section of the grid computing node relative to the original initial section is greater than 0, the voltage deviation is judged as an upper voltage deviation.

[0035] If the voltage deviation of the intra-day section of the grid computing node relative to the original initial section is less than 0, the voltage deviation is judged as a lower voltage deviation.

[0036] Further, the correction of the upper and lower limits of the voltage of the grid computing node according to the upper or lower voltage deviation of the intra-day section of the grid computing node relative to the original initial section comprises:

[0037] The corrected upper and lower limits of the voltage of the grid computing node are calculated according to the following formula:

[0038]

[0039] In the formula, i is the serial number of the grid computing node; t in,max is the serial number of the maximum intra-day section; V i is the upper and lower limits of the voltage of the i-th grid computing node; V ' i is the corrected upper and lower limits of the voltage of the i-th grid computing node; max and min are the maximum and minimum functions respectively; are the upper voltage deviations of the 1st, 2nd, t in ,max th intra-day sections of the i-th node relative to the original initial section respectively; are the lower voltage deviations of the 1st, 2nd, t in,max th intra-day sections of the i-th node relative to the original initial section respectively.

[0040] Further, the regional reactive voltage decision-making according to the discrete reactive power source action plan in the day before and the corrected limit value of the intra-day grid computing node voltage in the real-time scale comprises:

[0041] If there is a discrete reactive power source action plan in the day before at the current time, whether the discrete reactive power source action plan in the day before at the current time satisfies the following constraint condition is judged based on the corrected limit value of the intra-day grid computing node voltage, and if it satisfies, the discrete reactive power source action plan in the day before is executed:

[0042]

[0043] In the formula, i is the serial number of the grid computing node; V i is the current voltage value of the i-th grid computing node; V ' ithe modified upper and lower voltage limits of the i th calculation node of the power grid; p is the action number of the discrete reactive power source; n is the total number of discrete reactive power sources C ΔQ is the total number of discrete reactive power sources planned to act at the current moment p is the reactive power injection of the power grid after the p th discrete reactive power source acts

[0044] Based on the voltage correction limit of the calculation node of the power grid within the day, the regional voltage control model for regulating the reactive power output of the continuous reactive power source is used to determine the reactive power voltage control strategy of the continuous reactive power source within the region at the current moment;

[0045] The regional voltage control model is as follows:

[0046]

[0047] In the formula, i is the sequence number of the calculation node of the power grid within the region; n is the total number of calculation nodes of the power grid within the region; V p , is the current voltage and voltage target value of the regional hub bus; is the voltage-reactive power sensitivity of the continuous reactive power source within the region to the regional hub bus, ΔQ g is the reactive power regulation change of the continuous reactive power source within the region, V i , and V ' i are the current voltage, the modified upper voltage limit and the modified lower voltage limit of the i th calculation node within the region respectively; is the voltage-reactive power sensitivity of the continuous reactive power source within the region to the regional bus; Q g , and Q g are the current reactive power, the upper reactive power limit and the lower reactive power limit of the continuous reactive power source within the region respectively.

[0048] Further, the regional reactive power voltage decision at the real-time scale according to the day-ahead discrete reactive power source action plan and the voltage correction limit of the calculation node of the power grid within the day further comprises:

[0049] If it is judged that the day-ahead discrete reactive power source action plan at the current moment does not satisfy the constraint condition, the discrete reactive power source action plan is not executed;

[0050] Based on the voltage correction limit of the calculation node of the power grid within the day, the regional voltage control model for regulating the reactive power output of the continuous reactive power source is used to determine the reactive power voltage control strategy of the continuous reactive power source within the region at the current moment.

[0051] Further, the regional reactive power voltage decision at the real-time scale according to the day-ahead discrete reactive power source action plan and the voltage correction limit of the calculation node of the power grid within the day further comprises:

[0052] If there is no daytime discrete reactive power source operation plan at the current time, then the regional voltage control model for adjusting the reactive power output of the continuous reactive power source is used to determine the reactive voltage control strategy for the continuous reactive power source in the region at the current time.

[0053] Secondly, a multi-time-scale coordinated reactive power and voltage optimization control system includes:

[0054] The day-ahead scale decision module is used to determine the action plan of discrete reactive power sources at the day-ahead time scale based on the active power load forecast information of the grid load nodes, the active power output forecast information of the renewable energy nodes, and the power generation plan information of the renewable energy nodes.

[0055] The intraday-scale calculation module is used to solve for the voltage correction limit of the power grid calculation node based on the active power load prediction information of the power grid load node and the active power output prediction information of the new energy node at the intraday time scale.

[0056] The real-time scale control module is used to make regional reactive voltage decisions in real time based on the day-ahead discrete reactive power source operation plan and the intraday grid calculation node voltage correction limit.

[0057] The beneficial technical effects achieved by this invention are as follows:

[0058] This invention is based on application information such as day-ahead load, new energy forecast, intraday load, and new energy forecast. It considers the role of discrete reactive power sources in "peak shaving and valley filling" of voltage changes over long time scales, and decomposes and evaluates the role of continuous reactive power sources in smoothing small voltage disturbances over short time scales. It evaluates reactive power decision-making from multiple time scales and optimizes reactive power resource decisions over long time scales. This improves grid voltage quality, promotes the absorption of new energy, and provides voltage and reactive power control means for the safe operation of new power grids with large-scale grid connection of new energy. Attached Figure Description

[0059] Figure 1 A flowchart of a multi-time-scale coordinated reactive voltage optimization control method provided in an embodiment of the present invention;

[0060] Figure 2 This is a block diagram of a multi-time-scale coordinated reactive power and voltage optimization control system provided in an embodiment of the present invention. Detailed Implementation

[0061] The present invention will be further described below with reference to specific embodiments. These embodiments are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0062] Combination Figure 1As shown, a multi-time scale coordinated reactive voltage optimization control method comprises the following steps:

[0063] Step 1, in the day-ahead time scale, according to the day-ahead section of the power grid load node active load prediction information, new energy node active output prediction information and new energy node power generation plan information, the day-ahead section of the discrete reactive power source action plan is determined;

[0064] This step specifically includes:

[0065] Step 101, according to the day-ahead section of the power grid load node active load, new energy node active output and new energy node active plan, the voltage deviation of the power grid calculation node in the day-ahead continuous section is calculated;

[0066] Wherein, the voltage deviation of the power grid calculation node in the day-ahead continuous section is calculated according to the following formula:

[0067]

[0068] In the formula, i is the node sequence number of the power grid, and n d is the maximum node sequence number of the power grid; t and t-1 are the day-ahead section sequence numbers; j is the load sequence number, n ld is the maximum load node sequence number of the power grid; k is the new energy sequence number, n g is the maximum new energy node sequence number of the power grid; ΔV i,t is the voltage deviation of the i-th node in the t-th day-ahead section relative to the previous day-ahead section; V i,t and V i,t-1 are the voltage values of the i-th calculation node in the t-th and t-1 day-ahead sections, respectively; is the active power of the j-th load node in the t-th day-ahead section to the i-th node voltage-active power sensitivity; and P are the active loads of the j-th load node in the t-th and t-1 day-ahead sections, respectively; is the active power of the k-th new energy node in the t-th day-ahead section to the i-th node voltage-active power sensitivity; and P are the active outputs of the k-th new energy node in the t-th and t-1 day-ahead sections, respectively; is the active plan of the k-th new energy node in the t-th day-ahead section;

[0069] is the active output change evaluation value of the k-th new energy node in the t-1 to t day-ahead sections based on the new energy output prediction and plan.

[0070] The voltage value of the power grid calculation node in each day-ahead section is calculated according to the following formula:

[0071]

[0072] where i is the grid computing node number; t and t-1 are the day-ahead section numbers; m is the day-ahead section number; V i,t , V i,t-1 , V i,0 are the voltage values of the i-th computing node at the t-th, t-1-th, and 0-th day-ahead sections, respectively; ΔV i,t is the voltage deviation of the i-th node at the t-th day-ahead section relative to the previous day-ahead section.

[0073] Through the above formula, it can be determined which nodes and time periods of the grid will have a larger voltage variation trend, so as to facilitate the determination of which discrete reactive power sources to use at which time and place to perform peak shaving and valley filling.

[0074] Step 103: According to the voltage variation law of the day-ahead section grid computing node, it is evaluated whether the discrete reactive power source action plan needs to be increased.

[0075] According to the voltage variation law of the i-th node, it is evaluated whether the discrete reactive power source action plan needs to be increased:

[0076]

[0077] In formula (3), i is the grid computing node number; V i,t , V i,t are the voltage value, upper limit, and lower limit of the i-th computing node at the t-th day-ahead section; the formula contains three conditions, the first condition is that V i,t is not greater than the upper limit, the second condition is that V i,t is not less than the lower limit, and the third condition is that V i,t is not out of limit. When the first two conditions are triggered, the discrete reactive power source action plan needs to be increased, and step 104 is executed, otherwise the first step of calculating the discrete reactive power source action plan of the next section is continued until the day-ahead section traversal is completed.

[0078] Step 104: After determining that the day-ahead section needs to increase the discrete reactive power source action plan, the voltage deviation of the grid computing node at the t-th and subsequent day-ahead sections is corrected through the following formula: m

[0079]

[0080] In formula (4), i is the grid computing node number; t is the day-ahead section number; t m is the computing day-ahead section number, and the section has a discrete reactive power source action plan; p is the discrete reactive power source action number, and n C ​Total number of discrete reactive power sources planning action at time t; ΔV i,t Voltage deviation of the ith node at the tth day-ahead section relative to the previous day-ahead section; Voltage influence on the ith calculation node after the action of the discrete reactive power source at the tth day-ahead section; Voltage-reactive power sensitivity of the pth discrete reactive power source at the tth day-ahead section to the ith node; ΔQ t,p Reactive power injection of the pth discrete reactive power source after action at the tth day-ahead section. The selection of discrete reactive power sources can be selected by sensitivity size and reactive power reserve degree, and the correction to voltage out-of-limit is realized as much as possible with smaller cost.

[0081] Steps 101-104 are continuously performed to calculate the discrete reactive power source action plan of the next section until the day-ahead section traversal is completed.

[0082] Step 2, at the intra-day time scale, according to the grid load node active load prediction information of the intra-day section and the new energy node active output prediction information, the voltage correction limit value of the grid calculation node is solved;

[0083] Step 201, according to the active load of the grid load node and the active output of the new energy node of the intra-day section, the voltage deviation of the intra-day continuous section of the grid calculation node is calculated;

[0084] The voltage deviation of the intra-day continuous section of the grid calculation node is calculated according to the following formula:

[0085]

[0086] In formula (5), i is the grid calculation node number, and n d is the maximum node number of the grid; t in and t in -1 are the intra-day section numbers; j is the load number, n ld is the maximum load number of the grid; k is the new energy number, n g is the maximum new energy node number of the grid; Voltage deviation of the ith node at the tth intra-day section relative to the previous intra-day section; and are the voltage values of the ith calculation node at the t in and t in -1 intra-day sections, respectively; is the voltage value of the ith calculation node at the t in intra-day section; are the voltage-reactive power sensitivities of the jth load node active load at the t in and t in -1 intra-day sections, respectively; the active power of the kth new energy node in the tth daily section of the power grid; in the active power-voltage sensitivity of the ith node to the active power of the kth new energy node in the tth daily section of the power grid; the active power of the kth new energy node in the tth daily section of the power grid; in and the active power of the kth new energy node in the t in -1th daily section of the power grid.

[0087] Through the above formula, voltage fluctuations caused by power grid disturbances in a short time on each node of the power grid can be viewed, and the fluctuations can be responded to by continuous reactive power sources to prevent voltage out-of-limit caused by the fluctuations in advance.

[0088] In step 202, the voltage deviation of the power grid calculation node in the daily section relative to the original initial section is calculated according to the voltage deviation of the power grid calculation node in the daily continuous section, and it is judged whether the voltage deviation of the power grid calculation node in the daily section relative to the original initial section is an upper voltage deviation or a lower voltage deviation according to the direction of the voltage deviation of the power grid calculation node in the daily section relative to the original initial section.

[0089] Specifically, whether the voltage deviation of the power grid calculation node in the daily section relative to the original initial section is an upper voltage deviation or a lower voltage deviation can be judged according to the following formula:

[0090]

[0091] In formula (6), i is the serial number of the power grid calculation node; t in is the serial number of the daily section; m in is the serial number of the daily section; is the voltage deviation of the ith node in the m in th daily section relative to the previous daily section; are the voltage upper deviation and the voltage lower deviation of the ith node in the t in th daily section relative to the original initial section, respectively.

[0092] As can be seen from formula (6), for the ith node in the t in th daily section, there is either an upper voltage deviation or a lower voltage deviation, but not both.

[0093] In step 203, the upper and lower limits of the voltage of the power grid calculation node are corrected according to the upper voltage deviation or the lower voltage deviation of the power grid calculation node in the daily section relative to the original initial section.

[0094] Specifically, the corrected upper and lower limits of the voltage of the power grid calculation node are calculated according to the following formula:

[0095]

[0096] In the formula, i is the serial number of the power grid calculation node; t in,max is the maximum serial number of the daily section; V i are the upper and lower voltage limits of the i-th computing node of the power grid; V i are the corrected upper and lower voltage limits of the i-th computing node of the power grid; max and min are the maximum and minimum functions, respectively; are the upper and lower voltage limits of the i-th computing node of the power grid; in ,max are the upper and lower voltage limits of the i-th computing node of the power grid; in,max are the upper and lower voltage limits of the i-th computing node of the power grid. It can be seen from formula (7) that the corrected node voltage constraint interval at the intra-day scale is narrowed. are the upper and lower voltage limits of the i-th computing node of the power grid; in,max are the upper and lower voltage limits of the i-th computing node of the power grid. It can be seen from formula (7) that the corrected node voltage constraint interval at the intra-day scale is narrowed.

[0097] The constraint can be provided as a corrected constraint to the real-time scale for control. When the voltage operates within the constraint, it can prevent voltage out-of-limit phenomenon caused by power grid disturbance in the subsequent short time, and realize advanced preventive control of the power grid.

[0098] Step 3, at the real-time scale, according to the day-ahead discrete reactive power source action plan and the intra-day power grid computing node voltage correction limit, regional reactive power voltage decision is made.

[0099] Step 301, determine whether there is a day-ahead discrete reactive power source action plan at the current time, if there is, execute step 302, otherwise execute step 303;

[0100] Step 302, based on the intra-day power grid computing node voltage correction limit, determine whether the day-ahead discrete reactive power source action plan at the current time satisfies the following constraint condition:

[0101]

[0102] In the formula, i is the serial number of the power grid computing node; V i is the current voltage value of the i-th computing node of the power grid; V i are the corrected upper and lower voltage limits of the i-th computing node of the power grid; p is the action serial number of the discrete reactive power source, n C is the total number of discrete reactive power sources planned to act at the current time; ΔQ p is the power grid reactive power injection after the p-th discrete reactive power source acts;

[0103] If the constraint condition is satisfied, execute the day-ahead discrete reactive power source action plan, and continue to execute step 303 after the discrete reactive power source acts;

[0104] If the constraint condition is not satisfied, it is judged that the reactive power equipment planning of the discrete reactive power source is abnormal, the planning is cancelled, and step 303 is directly executed.

[0105] In step 303, the voltage correction limit of the intra-day power grid calculation node is calculated, and the pre-established regional voltage control model of the continuous reactive power source is used to determine the reactive power voltage control strategy of the continuous reactive power source in the region at the current time.

[0106] The regional voltage control model is as follows:

[0107]

[0108] In the formula, i is the sequence number of the grid calculation node in the region; n is the total number of grid calculation nodes in the region; V p 、 is the current voltage and voltage target value of the regional hub bus; is the voltage-reactive power sensitivity of the continuous reactive power source in the region to the regional hub bus, and ΔQ g is the reactive power regulation change of the continuous reactive power source in the region, V i 、 and V ' i are the current voltage, the corrected upper voltage limit and the corrected lower voltage limit of the i th calculation node in the region respectively; is the voltage-reactive power sensitivity of the continuous reactive power source in the region to the regional bus; Q g 、 and Q g are the current reactive power, the upper reactive power limit and the lower reactive power limit of the continuous reactive power source in the region respectively.

[0109] From the real-time scale, step 302 realizes the voltage control decision of the discrete reactive power source, and step 303 realizes the reactive power voltage decision of the continuous reactive power source, realizes the decoupling of the two, and improves the convergence of the scheme.

[0110] In the specific embodiment, the calculation starts at the day-ahead scale (every morning), the voltage change trend of the day is evaluated through the prediction information and the generation plan information, and the action plan of the discrete reactive power source is generated; the calculation starts at the intra-day scale (every 2 hours), the voltage fluctuation range within 2 hours is evaluated through the prediction information, and the pre-control direction of the continuous quantity is corrected; the calculation starts at the real-time scale (every 10 seconds), the action of the discrete quantity is executed according to the day-ahead and intra-day calculation, and the regional secondary voltage coordination control is realized according to the correction constraint.

[0111] Compared with the traditional method, the method fully considers the reactive voltage control characteristics of discrete and continuous reactive power sources, evaluates the reactive voltage decision in multiple dimensions in a long time scale, makes the discrete quantity track the voltage change trend of the power grid, makes the continuous quantity respond to the voltage fluctuation of the power grid, reduces the action frequency of the discrete quantity, improves the power grid voltage operation instruction, and is suitable for actual engineering field.

[0112] The method can greatly improve the voltage distribution imbalance and voltage fluctuation problem of the new power system caused by reactive voltage after large-scale grid connection of new energy, has high calculation efficiency, and has basically consistent calculation convergence degree with the traditional two-level voltage control, can greatly support new energy consumption, and provides a technical means for safe operation of the power grid voltage.

[0113] In another embodiment, as shown in Figure 2 a multi-time scale coordinated reactive voltage optimization control system comprises:

[0114] The day-ahead scale decision module is configured to determine the discrete reactive power source action plan of the day-ahead section according to the active load prediction information of the power grid load node, the active output prediction information of the new energy node and the power generation plan information of the new energy node in the day-ahead time scale.

[0115] The day-ahead scale decision module is configured to determine the discrete reactive power source action plan of the day-ahead section according to the active load prediction information of the power grid load node, the active output prediction information of the new energy node and the power generation plan information of the new energy node in the day-ahead time scale.

[0116] The real-time scale control module is configured to make regional reactive voltage decision according to the discrete reactive power source action plan of the day-ahead and the voltage correction limit value of the day-in grid calculation node in the real-time scale.

[0117] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can be in the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the present application can be in the form of a computer program product implemented on one or more computer usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer usable program code.

[0118] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 one or more flow or blocks

[0119] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 one or more flow or blocks

[0120] The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks. Figure 1 one or more flow or blocks Figure 1 one or more flow or blocks

[0121] The embodiments of the present application described above are merely intended to illustrate the principles of the present application, and the present application is not limited to the above-described embodiments. The above-described embodiments are merely illustrative, and are not intended to limit the present application. Those skilled in the art can make many modifications without departing from the spirit and scope of the present application, and these modifications are also intended to fall within the scope of the present application.

Claims

1. A multi-time-scale coordinated reactive power and voltage optimization control method, characterized in that, include: On the day-ahead time scale, the action plan of discrete reactive power sources on the day-ahead section is determined based on the active power load forecast information of the grid load nodes, the active power output forecast information of the renewable energy nodes, and the power generation plan information of the renewable energy nodes. On an intraday timescale, based on the active power load forecast information of the grid load nodes and the active power output forecast information of the new energy nodes at intraday cross-sections, the voltage correction limit of the grid calculation nodes is solved. At the real-time scale, regional reactive voltage decisions are made based on the day-ahead discrete reactive power source operation plan and the intraday grid calculation node voltage correction limit. The determination of the discrete reactive power source action plan for the day-ahead section includes: Based on the active load of the grid load nodes, the active power output of the new energy nodes, and the active power plan of the new energy nodes at the day-ahead cross section, calculate the voltage deviation of the grid calculation nodes at the day-ahead continuous cross section. Based on the voltage deviation of the power grid calculation nodes in the aforementioned consecutive day sections, calculate the voltage value of the power grid calculation nodes in each day section; Based on the voltage change pattern of the day-ahead grid calculation nodes, assess whether it is necessary to add discrete reactive power source action plans for the day-ahead section, and formulate and generate discrete reactive power source action plans. The method for solving the voltage correction limits at power grid calculation nodes includes: Based on the active load of the grid load nodes and the active power output of the new energy nodes in the intraday section, calculate the voltage deviation of the intraday continuous section of the grid calculation node. Based on the voltage deviation of the continuous sections within the day of the power grid computing node, calculate the voltage deviation of the intraday section of the power grid computing node relative to the original initial section, and determine whether the voltage deviation of the intraday section of the power grid computing node relative to the original initial section is an upper voltage deviation or a lower voltage deviation based on the direction of the voltage deviation of the intraday section relative to the original initial section. Based on the intraday voltage deviation or lower voltage deviation of the grid calculation node relative to the original initial section, the upper and lower limits of the grid calculation node voltage are corrected. The process, at a real-time scale, involves making regional reactive power voltage decisions based on the day-ahead discrete reactive power source operation plan and the intraday grid calculation node voltage correction limit, including: If a day-ahead discrete reactive power source action plan exists at the current time, based on the intraday grid calculation node voltage correction limit, determine whether the day-ahead discrete reactive power source action plan at the current time meets the following constraints. If it does, execute the day-ahead discrete reactive power source action plan: ； In the formula, i is the power grid computing node number; For the power grid Current voltage value of each computing node; , For the power grid Corrected upper and lower voltage limits for each computing node; For discrete reactive power source operation sequence numbers, This represents the total number of discrete reactive power sources that are scheduled to take action at the current moment. Let be the reactive power injection into the power grid after the p-th discrete reactive power source operates; Based on the intraday grid calculation node voltage correction limit, the reactive voltage control strategy of the continuous reactive source in the region at the current moment is determined by using the pre-established regional voltage control model for adjusting the reactive power output of the continuous reactive source. The regional voltage control model is as follows: ； In the formula, i is the serial number of the power grid computing node in the region; n is the total number of power grid computing nodes in the region; , These are the current voltage and target voltage values ​​of the central bus within the region; It is the sensitivity of continuous reactive power source regulation within the region to the voltage-reactive power of the regional central bus. This refers to the change in reactive power regulation of continuous reactive power sources within the region. , and These are the current voltage value, the corrected upper voltage limit, and the corrected lower voltage limit of the i-th calculation node within the region, respectively; The sensitivity of continuous reactive power sources within the region to the regional bus voltage-reactive power; , and These represent the current reactive power, upper reactive power limit, and lower reactive power limit of continuous reactive power sources within the region.

2. The multi-time-scale coordinated reactive power and voltage optimization control method according to claim 1, characterized in that, The voltage deviation of the power grid calculation nodes in the aforementioned continuous section is calculated according to the following formula: In the formula, i is the power grid computing node number, and The maximum node number in the power grid; and j is the section number before the date; j is the load number. k is the maximum sequence number of the power grid load node; k is the sequence number of the new energy source. The maximum sequence number of the new energy node in the power grid; The voltage deviation of the i-th node at the t-th day relative to the previous day's cross section; and The first and The first section of the recent cross-section Voltage values ​​of each computing node; For the first The active power of the j-th load node at the current cross section is sensitive to the voltage-active power of the i-th node. The first and The first section of the recent cross-section Active load of each load node; For the first The active power of the k-th renewable energy node at the current cross-section corresponds to the voltage-active power sensitivity of the i-th node. The first and The kth renewable energy node at the current section has an active power output; For the first The active power plan of the kth new energy node at the current cross section; To base the forecast and planning of new energy output on the first arrive The assessed value of the change in active power output of the kth renewable energy node at the current cross section.

3. The multi-time-scale coordinated reactive power and voltage optimization control method according to claim 1, characterized in that, The assessment of whether a discrete reactive power source action plan needs to be added to the day-ahead section based on the voltage change pattern of the calculated nodes of the power grid includes: If the voltage value of the power grid calculation node at the current section meets the requirements... or Increase the action plan for discrete reactive power sources; If the voltage value of the power grid calculation node at the current section meets the requirements... No increase in the action plan of discrete reactive power sources; Where i is the grid computing node number; , , The first The first section of the day The voltage value, upper voltage limit, and lower voltage limit of each computing node.

4. The multi-time-scale coordinated reactive power and voltage optimization control method according to claim 3, characterized in that, After determining that the current section needs to increase the discrete reactive power source action plan, the following formula is used to modify the first... Voltage deviation of the power grid calculation nodes at the current and subsequent day sections: ； In the formula, i is the power grid computing node number; The section number is the one that was crossed a day prior. To calculate the day-ahead section number, there is a discrete reactive power source action plan for this section; For discrete reactive power source operation sequence numbers, Let be the total number of discrete reactive power sources scheduled to operate at time t. The voltage deviation of the i-th node at the t-th day relative to the previous day's cross section; The effect of the discrete reactive power source on the i-th calculation node after the operation of the discrete reactive power source on the t-th day is given. For the first The voltage-reactive power sensitivity of the p-th discrete reactive power source at the i-th node at the current cross-section; For the first The amount of reactive power injected into the power grid after the p-th discrete reactive power source operates at the current cross-section.

5. The multi-time-scale coordinated reactive power and voltage optimization control method according to claim 1, characterized in that, The voltage deviation of the intraday continuous sections of the power grid calculation node is calculated according to the following formula: In the formula, i is the power grid computing node number, and The maximum node number in the power grid; and j is the intraday section number; j is the load number. k is the maximum sequence number of the power grid load node; k is the sequence number of the new energy source. The maximum sequence number of the new energy node in the power grid; The voltage deviation of the i-th node at the t-th intraday section relative to the previous intraday section; and The first and The first section of the day Voltage values ​​of each computing node; For the first Active power sensitivity of the j-th load node to the voltage of the i-th node within a day; The first and The first section of the day Active load of each load node; For the first The active power of the k-th renewable energy node within a given day corresponds to the voltage-active power sensitivity of the i-th node. The first and The active power output of the kth renewable energy node at the intraday cross section.

6. The multi-time-scale coordinated reactive power and voltage optimization control method according to claim 1, characterized in that, The step of correcting the upper and lower limits of the grid computing node voltage based on the intraday voltage deviation or lower voltage deviation of the grid computing node relative to the original initial cross-section includes: The corrected upper and lower voltage limits for the power grid calculation nodes are calculated using the following formulas: ； In the formula, i is the power grid computing node number; The maximum intraday cross-sectional number; , For the power grid The upper and lower voltage limits for each computing node; , For the power grid Corrected upper and lower voltage limits for each computing node; , These are functions for the maximum and minimum values, respectively. , , These are the 1st, 2nd, and 3rd nodes of the i-th node, respectively. Voltage deviation of the intraday cross section relative to the original initial cross section; , , These are the 1st, 2nd, and 3rd nodes of the i-th node, respectively. Voltage deviation of the cross section relative to the original initial cross section within a day.

7. The multi-time-scale coordinated reactive power and voltage optimization control method according to claim 1, characterized in that, The process of making regional reactive power voltage decisions in real-time, based on the day-ahead discrete reactive power source operation plan and the intraday grid calculation node voltage correction limit, also includes: If it is determined that the current day-ahead discrete reactive power source action plan does not meet the aforementioned constraints, then the discrete reactive power source action plan will not be executed. Based on the intraday grid calculation node voltage correction limit, the regional voltage control strategy for continuous reactive power sources in the region at the current moment is determined using the aforementioned regional voltage control model for adjusting the reactive power output of continuous reactive power sources.

8. A multi-time-scale coordinated reactive power and voltage optimization control system, characterized in that, include: The day-ahead scale decision module is used to determine the action plan of discrete reactive power sources at the day-ahead time scale based on the active power load forecast information of the grid load nodes, the active power output forecast information of the renewable energy nodes, and the power generation plan information of the renewable energy nodes. The intraday-scale calculation module is used to solve for the voltage correction limit of the power grid calculation node based on the active power load prediction information of the power grid load node and the active power output prediction information of the new energy node at the intraday time scale. The real-time scale control module is used to make regional reactive voltage decisions in real time based on the day-ahead discrete reactive power source operation plan and the intraday grid calculation node voltage correction limit. The determination of the discrete reactive power source action plan for the day-ahead section includes: Based on the active load of the grid load nodes, the active power output of the new energy nodes, and the active power plan of the new energy nodes at the day-ahead cross section, calculate the voltage deviation of the grid calculation nodes at the day-ahead continuous cross section. Based on the voltage deviation of the power grid calculation nodes in the aforementioned consecutive day sections, calculate the voltage value of the power grid calculation nodes in each day section; Based on the voltage change pattern of the day-ahead grid calculation nodes, assess whether it is necessary to add discrete reactive power source action plans for the day-ahead section, and formulate and generate discrete reactive power source action plans. The method for solving the voltage correction limits at power grid calculation nodes includes: Based on the active load of the grid load nodes and the active power output of the new energy nodes in the intraday section, calculate the voltage deviation of the intraday continuous section of the grid calculation node. Based on the voltage deviation of the continuous sections within the day of the power grid computing node, calculate the voltage deviation of the intraday section of the power grid computing node relative to the original initial section, and determine whether the voltage deviation of the intraday section of the power grid computing node relative to the original initial section is an upper voltage deviation or a lower voltage deviation based on the direction of the voltage deviation of the intraday section relative to the original initial section. Based on the intraday voltage deviation or lower voltage deviation of the grid calculation node relative to the original initial section, the upper and lower limits of the grid calculation node voltage are corrected. The process, at a real-time scale, involves making regional reactive power voltage decisions based on the day-ahead discrete reactive power source operation plan and the intraday grid calculation node voltage correction limit, including: If a day-ahead discrete reactive power source action plan exists at the current time, based on the intraday grid calculation node voltage correction limit, determine whether the day-ahead discrete reactive power source action plan at the current time meets the following constraints. If it does, execute the day-ahead discrete reactive power source action plan: ； In the formula, i is the power grid computing node number; For the power grid Current voltage value of each computing node; , For the power grid Corrected upper and lower voltage limits for each computing node; For discrete reactive power source operation sequence numbers, This represents the total number of discrete reactive power sources that are scheduled to take action at the current moment. Let be the reactive power injection into the power grid after the p-th discrete reactive power source operates; Based on the intraday grid calculation node voltage correction limit, the reactive voltage control strategy of the continuous reactive source in the region at the current moment is determined by using the pre-established regional voltage control model for adjusting the reactive power output of the continuous reactive source. The regional voltage control model is as follows: ； In the formula, i is the serial number of the power grid computing node in the region; n is the total number of power grid computing nodes in the region; , These are the current voltage and target voltage values ​​of the central bus within the region; It is the sensitivity of continuous reactive power source regulation within the region to the voltage-reactive power of the regional central bus. This refers to the change in reactive power regulation of continuous reactive power sources within the region. , and These are the current voltage value, the corrected upper voltage limit, and the corrected lower voltage limit of the i-th calculation node within the region, respectively; The sensitivity of continuous reactive power sources within the region to the regional bus voltage-reactive power; , and These represent the current reactive power, upper reactive power limit, and lower reactive power limit of continuous reactive power sources within the region.

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