A new energy gathering area reactive voltage control method considering power factor

Abstract

The application discloses a new energy gathering area reactive power and voltage control method considering power factors, realizes new energy power grid reactive power and voltage coordinated control considering power factors, in one aspect, through adjusting new energy station unit reactive power output, affecting the mode of the central bus (the bus of the new energy gathering area centralized grid-connected substation) voltage value, to track the voltage optimization target value of the central bus in real time, on the other hand, in the process of preferentially tracking the realization of the central bus voltage optimization target value, the requirements of new energy station power factor balance are considered, the problem of unreasonable reactive power distribution or even circulating current among new energy stations is avoided, and therefore the automatic voltage control level of the new energy power grid is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of power grid dispatching, and in particular to a reactive power and voltage control method for a new energy collection area considering power factors. BACKGROUND

[0002] By the end of 2023, the installed capacity of power generation in China reached 292 GW, and the total installed capacity of renewable energy such as hydropower, wind power and solar power reached 147 GW, accounting for more than 50% of the total installed capacity of power generation, which is a historic breakthrough over the installed capacity of thermal power. Among them, the installed capacity of wind power and solar power has increased by about 5 times and 40 times respectively since 2013. The network structure is continuously improved, and the "artery" of the power grid is strengthened. By the end of 2023, State Grid has completed 35 ultra-high voltage projects in China, with a cumulative power transmission of more than 2.9 trillion kWh, which has effectively promoted the optimal allocation of power resources in the country.

[0003] With the advancement of the construction of new power systems, the installed capacity of new energy in the power grid is increasing, and new energy station collection areas are formed in some areas rich in wind and light resources. The problem of reactive power and voltage control in the new energy collection area has become prominent. Due to the randomness and uncertainty of new energy generation, the conventional automatic voltage control often causes unreasonable distribution of reactive power between new energy stations and even internal circulation in the process of optimizing the voltage of the bus in the new energy collection area, which reduces the available reactive power reserve margin of the station in the new energy collection area and to some extent affects the voltage safety and stability level of the new energy collection area. SUMMARY

[0004] The purpose of the present application is to provide a reactive power and voltage control method for a new energy collection area considering power factors.

[0005] In order to achieve the above-mentioned purpose, the present application is implemented according to the following technical scheme:

[0006] The present application comprises the following steps:

[0007] S1: Obtain the model of the new energy power grid coordination control area: read the power grid model and perform topological analysis to identify the substations and their subordinate new energy stations in the coordination control area;

[0008] S2: Calculate the reactive power and voltage sensitivity information: use the power flow calculation method to obtain the sensitivity information of the transformer and the new energy unit to the bus voltage;

[0009] S3: Obtain the initial section operating state information: based on the sensitivity information, determine the power grid operating state in the current control period;

[0010] S4: Determine whether the central bus voltage needs to be optimized: calculate the deviation between the sampling value of the bus voltage and the optimization target value, and determine whether the reactive power output needs to be adjusted;

[0011] S5: generating new energy station bus voltage control strategy: adjusting the reactive power output of new energy station units to meet the optimization target of the hub bus voltage;

[0012] S6: determining the power factor condition: if the bus voltage optimization has been achieved, adjusting the reactive power output based on the power factor condition of the new energy station;

[0013] S7: generating transformer reactive power control strategy: adjusting the reactive power output of the new energy station transformer according to the power factor to ensure reasonable distribution;

[0014] S8: coordinating the reactive power output of the new energy station and the transformer: ensuring that the adjusted reactive power output is reasonably distributed between the new energy station and the transformer to maintain grid stability.

[0015] The beneficial effects of the present application are:

[0016] The present application is a new energy collection area reactive voltage control method considering power factor. Compared with the prior art, the present application can track the optimization target of the hub bus voltage in the new energy collection area while considering the realization of the power factor balance of each new energy station in the new energy collection area, avoiding the problem of unreasonable reactive power distribution or even circulating current between new energy stations in the same coordinated control area. Thus, the overall reactive voltage safe and stable operation of the new energy collection area power grid is ensured, providing strong support for large-scale new energy power consumption and transmission in the new energy collection area. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is the flow chart of the method of the present application. DETAILED DESCRIPTION

[0018] The present application will be further described below in conjunction with the drawings and specific embodiments, the illustrative embodiments and the description of the present application are used to explain the present application, but not as a limitation of the present application.

[0019] The embodiment of the application provides a new energy gathering area reactive voltage control method considering a power factor, including: obtaining a new energy power grid coordinated control area model; calculating reactive voltage sensitivity information of a transformer and a unit in each new energy power grid coordinated control area to bus voltage at the beginning of a current control period; based on the reactive voltage sensitivity information, obtaining initial section operation state information of the new energy power grid at the beginning of the current control period; based on the operation state information, determining whether the new energy power grid coordinated control area needs to track an optimization target value of a hub bus voltage; wherein, if the hub bus voltage optimization target value needs to be tracked, the reactive power output of a new energy station unit is coordinated and controlled according to the hub bus voltage, and a corresponding new energy station bus voltage control strategy is generated; if the hub bus voltage optimization target value has been tracked, the reactive power output of the new energy station unit is coordinated and controlled according to the power factor of the new energy station, and a corresponding new energy station transformer reactive power control strategy is generated.

[0020] The overall flow of the application is shown in Figure 1 , including the following steps:

[0021] S1: Obtain a current day new energy gathering area power grid (referred to as: new energy power grid) model and perform topological analysis to obtain a new energy power grid coordinated control model for automatic voltage control; the specific steps are as follows:

[0022] S1.1: Let the current day be D m , read the current day power grid model G m and perform topological analysis:

[0023] Topological analysis is performed on any 500kV substation (new energy concentrated on-grid substation, regional center station) in the new energy gathering area in the power grid model G m , the new energy stations having electrical connection with the 220kV bus on the medium voltage side of the substation are searched, the 500kV substation with the lower-level 220kV new energy station is marked as a new energy power grid 220kV coordinated control area, and is recorded as

[0024]

[0025] Wherein, is the 220kV bus information of the pth 500kV substation in the kth coordinated control area, is the 220kV bus information of the ith new energy station in the kth coordinated control area, is the 220kV transformer information of the tth new energy station in the kth coordinated control area, is the unit information of the gth new energy station in the kth coordinated control area.

[0026] In the automatic voltage control of the new energy power grid, the 220kV bus of the 500kV substation is generally selected as the central bus, and the 220kV bus of the new energy station is selected as the control bus.

[0027] S1.2: Traverse the power grid model G m All 500kV substations in the new energy collection area form K new energy power grid 220kV coordinated control areas (referred to as coordinated control areas), and finally obtain the coordinated control area model Z of the new energy power grid m For:

[0028]

[0029] Wherein, K represents the total number of 220kV coordinated control areas in the new energy power grid.

[0030] S2: According to the new energy power grid coordinated control area model of step S1, the sensitivity information of the 220kV transformer and the new energy unit to the bus voltage of each new energy power grid coordinated control area at the beginning of the current control period is obtained.

[0031] In this embodiment, the time at the beginning of the current control period in the automatic voltage control of the new energy power grid is T c , the serial number of the 220kV transformer in the kth coordinated control area is set as t, t=1, ……T, T represents the total number of 220kV transformers in the coordinated control area, and the serial number of the new energy unit in the kth coordinated control area is set as g, g=1, ……G, G represents the total number of new energy units in the coordinated control area.

[0032] Through power flow calculation, the sensitivity information of the tth 220kV transformer and the gth new energy unit in the kth coordinated control area to the voltage of any bus (including the 220kV central bus and the 220kV control bus) at different times can be obtained. Taking the T c time at the beginning of the current control period as an example, the sensitivity information Sens c of the 220kV transformer and the new energy unit in the kth coordinated control area in the new energy power grid to the bus voltage at the T k,c time is set as:

[0033]

[0034] Wherein, is the sensitivity information of the tth transformer in the kth coordinated control area to the bus voltage at the T c time, is the sensitivity information of the gth new energy unit in the kth coordinated control area to the bus voltage at the T c time;

[0035] S2.1: Transformer sensitivity information to bus voltage

[0036]

[0037] in, For the T c The sensitivity information of the t-th transformer in the k-th coordinated control area to the 220kV central bus voltage of the p-th substation; For the T c Sensitivity information of the t-th transformer in the k-th coordinated control area to the 220kV control bus voltage of the i-th new energy station.

[0038] S2.2: Sensitivity information of new energy units to bus voltage

[0039]

[0040] in, For the T c The sensitivity information of the g-th renewable energy unit in the k-th coordinated control area to the 220kV central bus voltage of the p-th substation; For the T c Sensitivity information of the g-th renewable energy unit in the k-th coordinated control area to the 220kV control bus voltage of the i-th renewable energy station.

[0041] S3: Based on the new energy grid coordinated control area model in step S1 and the sensitivity information of the 220kV transformers and new energy units in each new energy grid coordinated control area to the bus voltage in step S2, the initial cross-section operating status information of the new energy grid at the beginning of the current control cycle is obtained. The specific steps are as follows:

[0042] S3.1: Based on the new energy grid coordinated control area model of step S1 and the voltage sensitivity information of 220kV transformers and new energy units to the bus voltage in each new energy grid coordinated control area of ​​step S2, obtain the voltage sensitivity information of the new energy grid at the first T c Initial cross-section information at time F m,c :

[0043]

[0044] Wherein, the subscript m corresponds to the date D m , subscript c corresponds to the Tth c At time t, the subscript k corresponds to the kth coordinated control area of ​​the new energy grid. For the T c The kth coordinated control area model at time, Sens k,c For the T cSensitivity information of 220kV transformers and new energy units to bus voltage in the kth coordinated control area at time.

[0045] Among them, the T c Model of the kth coordinated control area at time for:

[0046]

[0047] in, In the regional model In the T c Status information at all times.

[0048] It should be noted that since the collected values ​​of the power grid model are changing in real time, the subscript c is marked as corresponding to the Tth c The state at each moment, the operating state information at different moments is not completely consistent. When each control cycle arrives, the regional model operating state information corresponding to the moment needs to be updated (without re-analyzing the model topology).

[0049] S3.2: According to Section T c Initial section information at time T, check the new energy grid c The operating status at the moment. For the k-th new energy grid coordination control area, it includes:

[0050] S3.2.1: Set the serial number of the 220kV central bus in the kth coordinated control area to p, where p = 1, ... P, where P represents the total number of 220kV central bus in the kth coordinated control area, and Tth c Initial state information of the 220kV central bus in the kth coordinated control area at time for:

[0051]

[0052] in, The pth central bus is at the T c The voltage sampling value at the moment, The pth central bus is at the T c The voltage control lower limit at time , The pth central bus is at the T c The voltage control upper limit at the moment, The pth central bus is at the T c The optimized voltage target value at the moment.

[0053] in:

[0054]

[0055] S3.2.2: Set the serial number of the 220 kV control bus in the kth coordination control area as i, i = 1, …, I, I represents the total number of 220 kV control buses in the kth coordination control area, and the T c th moment initial state information of the 220 kV control bus in the kth coordination control area is:

[0056]

[0057] wherein, is the voltage sampling value of the ith control bus at the T c th moment, is the lower limit of voltage control of the ith control bus at the T c th moment, is the upper limit of voltage control of the ith control bus at the T c th moment.

[0058] It should be noted that the 220 kV control bus of the new energy station in the new energy grid coordination control area is taken as the control quantity, and there is no voltage optimization target value, and only the voltage needs to be kept within the control upper and lower limit range of the bus voltage, that is, to meet:

[0059] S3.2.3: Obtain the initial state information of the new energy unit in the kth coordination control area at the T c th moment is:

[0060]

[0061] wherein, is the reactive power output sampling value of the gth new energy unit in the kth coordination control area at the T c th moment, is the minimum available reactive power output of the gth new energy unit, is the maximum available reactive power output of the gth new energy unit, Xf g is the subscript of the 220 kV transformer corresponding to the gth new energy unit, Bs g is the subscript of the 220 kV control bus corresponding to the gth new energy unit.

[0062] S3.2.4: Obtain the initial state information of the 220 kV transformer in the kth coordination control area at the T c th moment is:

[0063]

[0064] wherein, is the T cThe active sampling value of the high-voltage side of the tth220kV transformer in the kth coordination control area at the moment, The minimum value of the available reactive power of the tth transformer, c The reactive sampling value of the high-voltage side of the tth220kV transformer in the kth coordination control area at the moment, The minimum value of the available reactive power of the tth transformer, The maximum value of the available reactive power of the tth transformer.

[0065] The minimum and maximum values of the available reactive power of the tth transformer can be obtained by accumulating the available reactive power output information of the new energy unit in step (3-2-3):

[0066]

[0067] S3.3: Calculate the change of the bus voltage when adjusting the reactive power of each transformer and new energy unit in each coordination control area.

[0068] According to the sensitivity information of the transformer to the bus voltage in step 2-1), the change of the bus voltage when adjusting the reactive power of the tth transformer in the kth coordination control area is calculated as follows:

[0069] Set the Tth moment as T c The adjustment amount of the reactive power of the tth transformer at the moment is ΔQ t,c Then we have:

[0070]

[0071] Where, ΔV p,c is the voltage change of the pth220kV central bus when the reactive power of the tth transformer in the kth coordination control area is adjusted by ΔQ t,c .

[0072]

[0073] Where, ΔV i,c is the voltage change of the ith220kV control bus when the reactive power of the tth transformer in the kth coordination control area is adjusted by ΔQ t,c .

[0074] According to the sensitivity information of the new energy unit to the bus voltage in step 2-2), the change of the bus voltage when adjusting the reactive power of the gth new energy unit in the kth coordination control area is calculated as follows:

[0075] Set the Tth moment as T c The adjustment amount of the reactive power of the gth new energy unit at the moment is ΔQ g,c Then we have:

[0076]

[0077] wherein, ΔV p,c is the reactive power adjustment ΔQ of the gth new energy unit in the kth coordinated control area g,c is the voltage variation of the pth 220 kV backbone bus.

[0078]

[0079] wherein, ΔV i,c is the reactive power adjustment ΔQ of the gth new energy unit in the kth coordinated control area g,c is the voltage variation of the ith 220 kV control bus.

[0080] S4: Based on the operating state information, determine whether the coordinated control area of the current new energy power grid needs to track the optimization target value of the backbone bus voltage. In this embodiment, the current new energy power grid coordinated control area is the kth coordinated control area.

[0081] S4.1: At the T c th moment, the 220 kV backbone bus operating state information in the kth coordinated control area is:

[0082]

[0083] Calculate the deviation of the voltage sampling value of each 220 kV backbone bus in the kth coordinated control area from the voltage optimization target value information:

[0084]

[0085] S4.2: At the T c th moment, the 220 kV transformer operating state information in the kth coordinated control area is:

[0086]

[0087] Calculate the power factor cscθ of the high voltage side of each 220 kV transformer in the kth coordinated control area t,c information:

[0088]

[0089] Calculate the average power factor of the high voltage side of the T 220 kV transformers in the kth coordinated control area information:

[0090]

[0091] wherein, is the active cumulative value of the high voltage side of the T 220 kV transformers in the kth coordinated control area, is the cumulative reactive power on the high-voltage side of T 220kV transformers in the kth coordinated control area.

[0092]

[0093] Calculate the deviation Δcscθ between the high-voltage side power factor and the average power factor of each 220kV transformer in the kth coordinated control area t,c information:

[0094]

[0095] S4.3: Determine the control operation status of the kth coordinated control area of ​​the new energy grid

[0096] First, detect the total P number of Is there a value greater than the optimization dead zone threshold? If there is a situation, it is marked that the coordinated control area needs to start voltage optimization control, and the process goes to step 5) to perform voltage optimization control in the coordinated control area, otherwise it goes to step 6) to perform power factor balancing control in the coordinated control area.

[0097] Then, a total of T Δcscθ in the kth coordinated control area are detected t,c Is there a value greater than the power factor balance dead zone threshold Δcscθ? dead If it exists, it is marked that the coordinated control area needs to start power factor balancing control, and step 6) is continued to perform power factor balancing control in the coordinated control area. Otherwise, step 7 is entered to scan the operation status of the next coordinated control area of ​​the new energy grid.

[0098] S5: Perform voltage optimization control on the new energy grid coordinated control area where the central bus voltage deviates from the optimization dead zone.

[0099] If the first T c At time k, the voltage of the pth 220kV central bus in the coordinated control area deviates from the optimization dead zone. At this time, it is necessary to adjust the reactive output of the renewable energy units in the coordinated control area to ensure that the 220kV control bus voltage of the renewable energy station is qualified (the control bus voltage operates within the upper and lower limits), so that the 220kV central bus voltage of the substation approaches the voltage optimization target value. In this embodiment, the method of constructing a CSVC coordinated secondary voltage optimization model is used to illustrate the process of voltage optimization control in the renewable energy power grid coordinated control area.

[0100] S5.1: In order to make the central bus voltage as close as possible to the voltage optimization target value, a central bus voltage deviation can be constructed. To optimize the target, the objective function of the quadratic programming model is adopted:

[0101]

[0102] Where ΔQ g is the reactive power adjustment of the new energy unit, which is the optimization variable of the function; Indicates the absolute value of the deviation between the central bus voltage optimization target value and the voltage sampling value; is the sensitivity of the reactive power of the new energy unit to the bus voltage in step 2-2); θ g is the reactive power balance index of the new energy unit; W p and W q are the two weight coefficients of the function.

[0103] S5.1.1: θ g As a reactive power balance indicator for new energy units, its meaning is:

[0104]

[0105] in, and They respectively represent the current reactive power sampling value of the new energy unit, the upper limit of available reactive power and the lower limit of available reactive power.

[0106] S5.1.2: Constraints on the optimization function include:

[0107] Central / control bus voltage maximum adjustment step:

[0108] Central bus voltage qualified:

[0109] Control bus voltage qualified:

[0110] Reactive power regulation range of new energy units:

[0111] Minimize the first part of the objective function by ΔQ g Adjust the reactive power output of the new energy unit to make the voltage of the central bus As close to the optimization target value as possible The second part is to calculate the g ‖ 2 Introducing it into the objective function, on the one hand, ensures the increase of reactive power regulation margin of new energy units, and on the other hand, promotes the reactive power output of each new energy unit in the region to develop in a balanced direction, which reflects the goal of achieving voltage optimization. At the same time, try to ensure the goal of balanced reactive output of new energy units.

[0112] S5.2: By solving the quadratic programming objective function, we can get the Tth c The reactive adjustment value ΔQ of the g-th renewable energy unit at timeg,c According to the sensitivity information of the new energy unit to the bus voltage in step 2-2), the T c The set value of the 220kV control bus voltage of the i-th new energy station in the k-th coordinated control area at time The information is:

[0113]

[0114] Where, ΔV i,c For the T c The voltage regulation of the i-th control bus in the k-th coordinated control area is calculated based on the reactive power regulation and voltage sensitivity of the new energy units that are topologically associated with the control bus:

[0115]

[0116] S5.3: Set the sequence number of the 220kV control bus strategy for generating new energy stations in the kth coordinated control area to i strg ,i strg =1,……I strg , I strg represents the total number of 220kV control bus strategies in the kth coordinated control area, forming the Tth c Strategy information for controlling bus voltage adjustment in the kth coordinated control area at time as follows:

[0117]

[0118] Set the control mode when the new energy station is tracking the bus voltage setting target When the new energy station is tracking the transformer reactive power setting target, the control mode

[0119] The strategy number of the control strategy information and the subscript of the control bus are in correspondence; the control bus strategy information Including the voltage setting value of the control bus and the current control mode, namely:

[0120]

[0121] in, For the T c The set value of the i-th control bus voltage at time, For the T c The control mode of the new energy station where the i-th control bus is located at the moment

[0122] S5.4: The automatic voltage control master station of the power grid sends the T c Time istrg The voltage setting value instruction of the 220kV control bus and the control mode instruction of the new energy station are realized. c The control strategy for adjusting the i-th control bus voltage in the k-th coordinated control area at time; after the new energy station automatic voltage control substation receives the new energy station control mode and the adjustment target value of the i-th control bus voltage, it adjusts the reactive output of the new energy unit to make the 220kV bus voltage as close as possible to the bus voltage set value issued by the master station.

[0123] Overall, by adjusting the T c At time k, the reactive power output of the new energy units in the coordinated control area is used to adjust the voltage of each control bus, so that the voltage of the 220kV central bus in the area gradually approaches its voltage optimization target value, thereby achieving the T c The goal of optimizing the voltage control of the 220kV central bus in the kth coordinated control area at time.

[0124] After completing T c After the central busbar of the kth coordinated control area is optimized, step 7 is entered to scan the operation status of the next coordinated control area of ​​the new energy power grid.

[0125] S6: Perform power factor balancing control on the new energy grid coordinated control area where the central bus voltage has been optimized.

[0126] If the first T c At the moment, the power factor on the high-voltage side of the t-th 220kV transformer in the k-th coordinated control area deviates from the power factor balance dead zone. At this time, it is necessary to adjust the reactive output on the high-voltage side of the 220kV transformer in the coordinated control area. While ensuring the optimization of the 220kV central bus voltage of the substation and the qualified 220kV control bus voltage of the new energy station (the control bus voltage operates within the upper and lower limits), the power factor on the high-voltage side of the 220kV transformer is close to the average power factor of the coordinated control area. In this embodiment, the method of constructing a CQSVC coordinated secondary reactive optimization model is used to illustrate the process of power factor balance control in the coordinated control area of ​​the new energy power grid.

[0127] S6.1: In order to make the power factor of the high voltage side of the 220kV transformer as close as possible to the average power factor of the coordinated control area, a reactive deviation value of the high voltage side of the 220kV transformer can be constructed. To optimize the target, the objective function of the quadratic programming model is adopted:

[0128]

[0129] Where ΔQ t is the reactive power adjustment on the high-voltage side of the 220kV transformer, which is the optimization variable of the function; represents the absolute value of the deviation between the reactive power optimization target value of the high-voltage side of the 220 kV transformer and the reactive power sampling value; is the sensitivity of the transformer reactive power to the bus voltage in step 2-1); θ i is the 220 kV bus voltage balance index of the new energy station; W p and W q are two weight coefficients of the function.

[0130] S6.1.1: As the reactive power optimization target value of the high-voltage side of the 220 kV transformer, its meaning is:

[0131]

[0132] is the reactive power optimization target value of the high-voltage side of the tth220 kV transformer at the T c time, and the calculation method is:

[0133]

[0134] wherein, the sign direction of is consistent with .

[0135] S6.1.2: θ i As the 220 kV bus voltage balance index of the new energy station, its meaning is:

[0136]

[0137] wherein, and respectively represent the current voltage sampling value of the 220 kV bus of the new energy station, the control upper limit and the control lower limit.

[0138] S6.1.3: The constraint conditions of the optimization function include:

[0139] The maximum step length of the reactive power adjustment of the 220 kV transformer:‖ΔQ t ‖<ΔQ step ;

[0140] Hub bus voltage optimization:

[0141] Control bus voltage qualification:

[0142] Reactive power regulation range of 220 kV transformer:

[0143] The first part of the objective function is minimized by ΔQ tAdjust the reactive power output of the high-voltage side of the transformer to make the reactive power of the high-voltage side of the 220kV transformer Close to the optimization target value The second part is to make ‖θ i ‖ 2 be introduced into the objective function, on the one hand, to ensure the adjustment margin of increasing the voltage of the new energy bus, and on the other hand, to promote the voltage of each new energy station in the region to develop in the direction of balance, which embodies the goal of balancing the voltage of the new energy station while achieving the reactive power optimization target .

[0144] S6.2: By solving this quadratic programming objective function, the reactive power adjustment amount ΔQ c of the high-voltage side of the tth 220kV transformer at the T t,c th moment is obtained, and the set value of the reactive power of the high-voltage side of the tth 220kV transformer in the kth coordinated control area at the T c th moment is further calculated .

[0145]

[0146] S6.3: Set the serial number of the generated 220kV transformer high-voltage side reactive power control strategy in the kth coordinated control area as t strg , t strg =1, ……T strg , T strg represents the total number of 220kV transformer high-voltage side reactive power control strategies in the kth coordinated control area, then the strategy information of the 220kV transformer reactive power adjustment in the kth coordinated control area at the T c th moment is formed .

[0147]

[0148] The strategy serial number and the subscript of the transformer in the control strategy information are corresponding relationship; the 220kV transformer control strategy information includes the 220kV transformer high-voltage side reactive power set value and the current control mode, that is:

[0149]

[0150] Wherein, is the set value of the tth 220kV transformer high-voltage side reactive power at the T c th moment, is the control mode of the new energy station where the tth 220kV transformer is located at the T c th moment

[0151] S6.4: The new energy grid automatic voltage control master station sends the T c Time t strg The set value instruction of reactive power on the high voltage side of 220kV transformer and the control mode instruction of new energy station are realized. c Control strategy for reactive power adjustment on the high-voltage side of the t-th 220kV transformer in the k-th coordinated control area at time; after receiving the control mode of the new energy station and the target value for reactive power adjustment on the high-voltage side of the t-th 220kV transformer, the new energy station substation adjusts the reactive power output of the new energy unit to make the reactive power on the high-voltage side of the 220kV transformer as close as possible to the transformer reactive power setting value issued by the master station.

[0152] Overall, by adjusting the T c At time k, the reactive power output of the new energy units in the coordinated control area is used to adjust the reactive power on the high-voltage side of each 220kV transformer, so that the power factor on the high-voltage side of the 220kV transformer in the area gradually approaches the regional power factor average, thereby achieving the T c The goal of power factor balancing control of 220kV transformers in the kth coordinated control area at time.

[0153] After completing T c After the central busbar of the kth coordinated control area is optimized, step 7 is entered to scan the operation status of the next coordinated control area of ​​the new energy power grid.

[0154] S7: Select the next new energy grid coordinated control area as the new current coordinated control area, and then return to step S4 until the reactive power and voltage control process of the K coordinated control areas of the new energy grid is completed. After the control is completed, the new current time is recorded as T' c , then we get the new energy grid at the first T′ c Cross-section status information F′ at the moment m,c :

[0155]

[0156] Among them, the superscript ' corresponds to the T' c time, The control partition model of the new energy grid is in the T′ c The state of the moment.

[0157] S7.1: Section T′ c The information of 220kV central bus and 220kV control bus in the kth coordinated control area at time is:

[0158]

[0159] in, For the T′ cThe 220kV central bus information in the kth coordinated control area at time, For the T′ c 220kV control bus information in the kth coordinated control area at time.

[0160] In the T′ c The sampling value information of the 220kV central bus voltage at time p for:

[0161]

[0162] In the T′ c The sampling value information of the 220kV control bus voltage at time i for:

[0163]

[0164] S7.2: Section T′ c The information of the new energy unit in the kth coordinated control area at time is:

[0165]

[0166] in, For the T′ c Reactive power information of the new energy units in the kth coordinated control area at time.

[0167] In the T′ c Reactive sampling value information of the g-th renewable energy unit at time for:

[0168]

[0169] S7.3: Section T′ c The information of 220kV transformer in the kth coordinated control area at time is:

[0170]

[0171] in, For the T′ c Reactive power information on the high-voltage side of the 220kV transformer in the kth coordinated control area at time.

[0172] In the T′ c Reactive sampling value information of the high-voltage side of the 220kV transformer at time t for:

[0173]

[0174] S8: At the next control cycle of the new energy grid automatic voltage control, c+1The time T c+1 The time T c The time T, first return to step 2) to calculate sensitivity, then use the new energy grid obtained in step 7) as the initial section operation state information of the new T c The time T, first return to step 2) to calculate sensitivity, then use the new energy grid obtained in step 7) as the initial section operation state information of the new T c The time T, first return to step 2) to calculate sensitivity, then use the new energy grid obtained in step 7) as the initial section operation state information of the new T m The time T, first return to step 2) to calculate sensitivity, then use the new energy grid obtained in step 7) as the initial section operation state information of the new T

[0175] Due to the difference in the adjustment capacity and response speed of the new energy stations, when the voltage of the hub bus in the new energy collection area reaches the optimization target value, there may be unreasonable reactive power distribution or even reactive power circulation between the new energy stations. The application uses a coordinated control strategy considering power factor in the reactive power and voltage control of the new energy grid, which ensures the optimization of the voltage of the hub bus and coordinates the reactive power output of the units of the new energy stations, thereby eliminating the unreasonable reactive power distribution between the new energy stations.

[0176] The application realizes the coordinated control of the reactive power and voltage of the new energy grid considering the power factor, which, on the one hand, adjusts the reactive power output of the units of the new energy stations to affect the voltage value of the hub bus (the bus of the centralized transmission substation of the new energy collection area) and track the voltage optimization target value of the hub bus in real time, and on the other hand, gives priority to tracking the voltage optimization target value of the hub bus and takes into account the requirement of balancing the power factor of the new energy stations, thereby avoiding the unreasonable reactive power distribution or even circulation between the new energy stations and improving the level of the automatic voltage control of the new energy grid.

[0177] The technical scheme of the application is not limited to the above specific embodiments, and any technical modification made according to the technical scheme of the application falls within the protection scope of the application.

Claims

1. A reactive voltage control method for a new energy collection area considering power factor, characterized in that: The following steps are involved: S1: Obtain the new energy grid coordinated control area model: read the grid model and perform topological analysis to identify the substations and their subordinate new energy stations within the coordinated control area; S2: Calculate reactive voltage sensitivity information: Use the power grid flow calculation method to obtain the sensitivity information of transformers and new energy units to bus voltage; S3: Obtaining initial section operation status information: Based on the sensitivity information, determine the grid operation status of the current control cycle; S4: Determine whether the central bus voltage needs to be optimized: Calculate the deviation between the bus voltage sampling value and the optimization target value to determine whether the reactive output needs to be adjusted; S5: Generate the bus voltage control strategy for the new energy station: adjust the reactive power output of the new energy station units to meet the optimization target of the central bus voltage; S6: Determine the power factor: If bus voltage optimization has been achieved, adjust the reactive power output based on the power factor of the new energy station; S7: Generate transformer reactive power control strategy: adjust the reactive power output of the new energy station transformer according to the power factor to ensure reasonable distribution; S8: Coordinate the reactive power output of renewable energy stations and transformers: Ensure that the adjusted reactive power output is reasonably distributed between renewable energy stations and transformers to maintain grid stability.

2. The reactive voltage control method for a new energy gathering area considering power factor according to claim 1 is characterized in that: The step S1 is specifically as follows: S1.1: Let the current day be D m , read the current day's power grid model G m And perform topological analysis: For the grid model G m Perform topological analysis on any 500kV substation in the new energy gathering area, search for new energy stations that are electrically connected to the 220kV busbar on the medium voltage side of the substation, and mark the 500kV substation with a lower-level 220kV new energy station as a new energy grid 220kV coordinated control area, recorded as in, is the 220kV bus information of the pth 500kV substation in the kth coordinated control area, is the 220kV busbar information of the i-th new energy station in the k-th coordinated control area, is the 220kV transformer information of the t-th new energy station in the k-th coordinated control area, The unit information of the g-th renewable energy station in the k-th coordinated control area; S1.2: Traverse the power grid model G m All 500kV substations in the new energy gathering area form K new energy grid 220kV coordinated control areas, and finally the coordinated control area model Z of the new energy grid is obtained. m for: Where K represents the total number of 220kV coordinated control areas in the new energy grid.

3. The reactive voltage control method for a new energy collection area considering power factor according to claim 2 is characterized in that: The step S2 is specifically as follows: let the time when the current control cycle starts in the automatic voltage control of the new energy grid be T c , set the serial number of the 220kV transformer in the kth coordinated control area to t, t = 1, ... T, T represents the total number of 220kV transformers in the coordinated control area, the serial number of the new energy unit in the kth coordinated control area is g, g = 1, ... G, G represents the total number of new energy units in the coordinated control area, set the kth coordinated control area in the new energy grid to be in the Tth c Sensitivity information of 220kV transformer and new energy unit to bus voltage at this moment k,c for: in, For the T c The sensitivity information of the t-th transformer to the bus voltage in the k-th coordinated control area at time, For the T c The sensitivity information of the g-th renewable energy unit to the bus voltage in the k-th coordinated control area at time; Transformer sensitivity information to bus voltage: in, For the T c The sensitivity information of the t-th transformer in the k-th coordinated control area to the 220kV central bus voltage of the p-th substation; For the T c The sensitivity information of the t-th transformer in the k-th coordinated control area to the 220kV control bus voltage of the i-th new energy station; Sensitivity information of new energy units to bus voltage: in, For the T c The sensitivity information of the g-th renewable energy unit in the k-th coordinated control area to the 220kV central bus voltage of the p-th substation; For the T c Sensitivity information of the g-th renewable energy unit in the k-th coordinated control area to the 220kV control bus voltage of the i-th renewable energy station.

4. The reactive voltage control method for a new energy gathering area considering power factor according to claim 3 is characterized in that: The step S3 specifically includes the following steps: S3.1: Obtain the new energy grid at step T according to steps S1 and S2 c Initial cross-section information F at time m,c : Wherein, the subscript m corresponds to the date D m , subscript c corresponds to the Tth c At time , the subscript k corresponds to the kth coordinated control area of ​​the new energy grid; For the T c The k-th coordinated control area model at time, Sens k,c For the T c The sensitivity information of 220kV transformers and renewable energy units to bus voltage in the kth coordinated control area at time; Among them, the T c Model of the kth coordinated control area at time for: in, In the regional model In the T c Status information at all times; S3.2: According to Section T c Initial section information at time T, check the new energy grid c The operating status at the moment; for the k-th new energy grid coordinated control area, the specific steps include: S3.2.1: Set the serial number of the 220kV central bus in the kth coordinated control area to p, where p = 1, ... P, where P represents the total number of 220kV central bus in the kth coordinated control area, and Tth c Initial state information of the 220kV central bus in the kth coordinated control area at time for: in, The pth central bus is at the T c The voltage sampling value at the moment, The pth central bus is at the T c The voltage control lower limit at time , The pth central bus is at the T c The voltage control upper limit at the moment, The pth central bus is at the T c The optimized voltage target value at the moment; in: S3.2.2: Set the serial number of the 220kV control bus in the kth coordinated control area to i, i = 1, ... I, I represents the total number of 220kV control buses in the kth coordinated control area, Tth c Initial state information of the 220kV control bus in the kth coordinated control area at time for: in, The i-th control bus is at the T c The voltage sampling value at the moment, The i-th control bus is at the T c The voltage control lower limit at time , The i-th control bus is at the T c The voltage control upper limit at the moment; S3.2.3: Obtain the T-th new energy unit in the k-th coordinated control area c Initial state information at the moment for: in, For the T c The reactive output sampling value of the g-th renewable energy unit in the k-th coordinated control area at time, The minimum available reactive power output of the g-th renewable energy unit, is the maximum available reactive power output of the g-th renewable energy unit, Xf g Bs is the subscript of the 220kV transformer corresponding to the g-th new energy unit. g The subscript of the 220kV control busbar corresponding to the g-th new energy unit; S3.2.4: Obtain the T-th location of the 220kV transformer in the k-th coordinated control area c Initial state information at the moment for: in, For the T c The active sampling value of the high-voltage side of the t-th 220kV transformer in the k-th coordinated control area at time, For the T c The reactive sampling value on the high-voltage side of the t-th 220kV transformer in the k-th coordinated control area at time, is the minimum value of the available reactive power of the t-th transformer, is the maximum value of the available reactive power of the t-th transformer; The minimum and maximum available reactive power values ​​of the t-th transformer can be obtained by accumulating the available reactive power output information of the new energy units in step S3.2.3: S3.3: Calculate the change in bus voltage during reactive power adjustment of each transformer and renewable energy unit in each coordinated control area: According to the sensitivity information of the transformer to the bus voltage in step S2, the change in bus voltage during reactive power adjustment of the t-th transformer in the k-th coordinated control area is calculated as follows: Set T c The reactive power adjustment of the transformer at time t is ΔQ t,c , then: Where, ΔV p,c is the reactive power adjustment ΔQ of the t-th transformer in the k-th coordinated control area t,c When , the voltage change of the pth 220kV central busbar; Where, ΔV i,c is the reactive power adjustment ΔQ of the t-th transformer in the k-th coordinated control area t,c When , the voltage change of the ith 220kV control busbar; According to the sensitivity information of the new energy generator to the bus voltage in step S2, the change in bus voltage during reactive power adjustment of the g-th new energy generator in the k-th coordinated control area is calculated as follows: Set T c The reactive power adjustment of the g-th renewable energy unit at the moment is ΔQ g,c , then: Where, ΔV p,c is the reactive power adjustment ΔQ of the g-th renewable energy unit in the k-th coordinated control area g,c When , the voltage change of the pth 220kV central busbar; Where, ΔV i,c is the reactive power adjustment ΔQ of the g-th renewable energy unit in the k-th coordinated control area g,c The voltage change of the i-th 220kV control busbar when .

5. The reactive voltage control method for a new energy gathering area considering power factor according to claim 4 is characterized in that: The step S4 is specifically as follows: S4.1: Section T c The operating status information of the 220kV central bus in the kth coordinated control area at time is: Calculate the deviation between the voltage sampling value of each 220kV central bus in the kth coordinated control area and the voltage optimization target value information: S4.2: Section T c The operating status information of the 220kV transformer in the kth coordinated control area at time is: Calculate the power factor cscθ on the high-voltage side of each 220kV transformer in the kth coordinated control area t,c information: Calculate the average power factor of the high-voltage side of T 220kV transformers in the kth coordinated control area information: in, is the accumulated active power on the high-voltage side of T 220kV transformers in the kth coordinated control area, is the cumulative reactive power value of the high-voltage side of T 220kV transformers in the kth coordinated control area; Calculate the deviation Δcscθ between the high-voltage side power factor and the average power factor of each 220kV transformer in the kth coordinated control area t,c information: S4.3: Determine the control operation status of the kth coordinated control area of ​​the new energy grid: First, detect the total P number of Is there a value greater than the optimization dead zone threshold? If there is a situation, it is marked that the coordinated control area needs to start voltage optimization control, and the process goes to step S5 to perform voltage optimization control in the coordinated control area. Otherwise, the process goes to step S6 to perform power factor balancing control in the coordinated control area. Then, a total of T Δcscθ in the kth coordinated control area are detected t,c Is there a value greater than the power factor balance dead zone threshold Δcscθ? dead if it exists, the coordinated control area is marked to start power factor balancing control, proceed to step S6 for coordinated control area power factor balancing control, otherwise proceeds to step S7 to scan the operation of the next coordinated control area of ​​the new energy grid.

6. The reactive voltage control method for a new energy gathering area considering power factor according to claim 5 is characterized in that: The step S5 comprises the following steps: S5.1: Construct a system based on the central bus voltage deviation To optimize the target, the objective function of the quadratic programming model is adopted: Where ΔQ g is the reactive power adjustment of the new energy unit, which is the optimization variable of the function; Indicates the absolute value of the deviation between the central bus voltage optimization target value and the voltage sampling value; is the sensitivity of the reactive power of the new energy unit to the bus voltage in step S2; θ g is the reactive power balance index of the new energy unit; W p and W q are the two weight coefficients of the function; S5.1.1: θ g As a reactive power balance indicator for new energy units, its meaning is: in, and Respectively represent the current reactive sampling value of the new energy unit S5.1.2: Constraints on the optimization function include: Central / control bus voltage maximum adjustment step: Central bus voltage qualified: Control bus voltage qualified: Reactive power regulation range of new energy units: S5.2: Obtain the Tth by solving the quadratic programming objective function c The reactive adjustment value ΔQ of the g-th renewable energy unit at time g,c According to the sensitivity information of the new energy unit to the bus voltage in step S2, the T c The set value of the 220kV control bus voltage of the i-th new energy station in the k-th coordinated control area at time The information is: Where, ΔV i,c For the T c The voltage regulation of the i-th control bus in the k-th coordinated control area is calculated based on the reactive power regulation and voltage sensitivity of the new energy units that are topologically associated with the control bus: S5.3: Set the sequence number of the 220kV control bus strategy for generating new energy stations in the kth coordinated control area to i strg ,i strg =1,……I strg , I strg represents the total number of 220kV control bus strategies in the kth coordinated control area, forming the Tth c Strategy information for controlling bus voltage adjustment in the kth coordinated control area at time as follows: Set the control mode when the new energy station is tracking the bus voltage setting target When the new energy station is tracking the transformer reactive power setting target, the control mode Control bus strategy information Including the voltage setting value of the control bus and the current control mode, namely: in, For the T c The set value of the i-th control bus voltage at time, For the T c The control mode of the new energy station where the i-th control bus is located at the moment S5.4: The new energy grid automatic voltage control master station sends the T c Time i strg The voltage setting value instruction of the 220kV control bus and the control mode instruction of the new energy station are realized. c The control strategy for adjusting the i-th control bus voltage in the k-th coordinated control area at time; after the new energy station automatic voltage control substation receives the new energy station control mode and the adjustment target value of the i-th control bus voltage, it adjusts the reactive output of the new energy unit to make the 220kV bus voltage as close as possible to the bus voltage set value issued by the master station.

7. The reactive voltage control method for a new energy gathering area considering power factor according to claim 6 is characterized in that: The step S6 comprises the following steps: S6.1: Construct a reactive deviation value based on the high voltage side of a 220 kV transformer To optimize the target, the objective function of the quadratic programming model is adopted: Where ΔQ t is the reactive power adjustment on the high-voltage side of the 220kV transformer, which is the optimization variable of the function; Indicates the absolute value of the deviation between the reactive power optimization target value and the reactive power sampling value on the high-voltage side of the 220kV transformer; is the sensitivity of the transformer reactive power to the bus voltage in step S2; θ i W is the voltage balance index of 220kV busbar in new energy station; p and W q are the two weight coefficients of the function; S6.1.1: As the target value for reactive power optimization on the high-voltage side of a 220kV transformer, its meaning is: For the T c The reactive power optimization target value of the high-voltage side of the 220kV transformer at time t is calculated as follows: in, The sign direction and consistent; S6.1.2: θ i As a 220kV bus voltage balance indicator for new energy stations, its meaning is: in, and They represent the current voltage sampling value, upper control limit and lower control limit of the 220kV busbar of the new energy station respectively; S6.1.3: Constraints on the optimization function include: The maximum step size of reactive power adjustment of 220kV transformer: ‖ΔQ t ‖<ΔQ step ; Central bus voltage optimization: Control bus voltage qualified: Reactive power regulation range of 220kV transformer: S6.2: By solving the quadratic programming objective function, we can get the T c The reactive adjustment ΔQ of the high-voltage side of the 220kV transformer at time t t,c , further calculations are performed to obtain the T c The set value of reactive power on the high-voltage side of the t-th 220kV transformer in the k-th coordinated control area at time The information is: S6.3: Set the sequence number of the reactive power control strategy for the high-voltage side of the 220kV transformer generated in the kth coordinated control area to t strg , t strg =1,……T strg , T strg represents the total number of reactive power control strategies on the high-voltage side of 220kV transformers in the kth coordinated control area, thus forming the Tth c Strategy information of reactive power adjustment of 220kV transformer in the kth coordinated control area at time as follows: The strategy number of the control strategy information and the transformer subscript are in correspondence; 220kV transformer control strategy information Including the reactive power setting value and current control mode of the high-voltage side of the 220kV transformer, namely: in, For the T c The set value of reactive power on the high-voltage side of the 220kV transformer at time t is: For the T c Control mode of the new energy station where the t-th 220kV transformer is located S6.4: The power grid automatic voltage control master station sends the T c Time t strg The set value instruction of reactive power on the high voltage side of 220kV transformer and the control mode instruction of new energy station are realized. c The control strategy for adjusting the reactive power on the high-voltage side of the t-th 220kV transformer in the k-th coordinated control area at time instant. After receiving the control mode of the new energy station and the target value for the reactive power adjustment on the high-voltage side of the t-th 220kV transformer, the new energy station substation adjusts the reactive power output of the new energy unit to make the reactive power on the high-voltage side of the 220kV transformer as close as possible to the transformer reactive power set value issued by the master station. After completing T c After the central busbar of the kth coordinated control area is optimized and controlled at time point, step S7 is entered to scan the operation status of the next coordinated control area of ​​the new energy power grid.

8. The reactive voltage control method for a new energy gathering area considering power factor according to claim 7 is characterized in that: The step S7 is specifically as follows: select the next new energy grid coordinated control area as the new current coordinated control area, and then return to step S4 until the reactive power voltage control process of the K coordinated control areas of the new energy grid is completed; after the control is completed, the new current time is recorded as T' c , then we get the new energy grid at the T′ c Cross-section status information F′ at the moment m,c : Among them, the superscript ' corresponds to the T' c time, The control partition model of the new energy grid is in the T′ c The state of the moment. S7.1: Section T′ c The information of 220kV central bus and 220kV control bus in the kth coordinated control area at time is: in, For the T′ c The 220kV central bus information in the kth coordinated control area at time, For the T′ c 220kV control bus information in the kth coordinated control area at time; In the T′ c The sampling value information of the 220kV central bus voltage at time p for: In the T′ c The sampling value information of the 220kV control bus voltage at time i for: S7.2: Section T′ c The information of the new energy unit in the kth coordinated control area at time is: in, For the T′ c Reactive power information of the new energy units in the kth coordinated control area at time; In the T′ c Reactive sampling value information of the g-th renewable energy unit at time for: S7.3: Section T′ c The information of 220kV transformer in the kth coordinated control area at time is: in, For the T′ c The reactive power information of the high-voltage side of the 220kV transformer in the kth coordinated control area at time T′ c Reactive sampling value information of the high-voltage side of the 220kV transformer at time t for:

9. The reactive voltage control method for a new energy gathering area considering power factor according to claim 8 is characterized in that: The step S8 is specifically as follows: at the next control cycle of the new energy grid automatic voltage control, c+1 At this moment, the T c+1 Time as T c At time T', first return to step S2 to calculate the sensitivity, and then use the new energy grid obtained in step S7 to calculate the sensitivity of the new energy grid at time T' c The section operation status information at the time is used as the new T c The initial section operation status information at the moment, and then repeat the process of step S4-step S7 to complete a new round of automatic voltage control of the new energy grid until the new energy grid is realized on date D m Automatic voltage control process at each control cycle.

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