CN104135013A - Wind-power-integration-responded electrical power system reactive voltage hierarchical control method - Google Patents

Abstract

The invention discloses a wind-power-integration-responded electrical power system reactive voltage hierarchical control method. According to the wind-power-integration-responded electrical power system reactive voltage hierarchical control method, regulating characteristics, the response speed and the switching mode of reactive compensation equipment are comprehensively considered; as for the reactive voltage problem caused by the fact that wind power is integrated into a power grid, an improved five-area map serves as the movement criteria, the zero-area scope is shrunk, an upper-stage control strategy is selected from a combination in a plurality of control modes with the artificial intelligence algorithm, and the voltage of a power grid side system is regulated and kept within limiting values; as for voltage threshold crossing problem possibly caused by the deviation between a wind power predicted value and an actual value, a movement area, in the improved five-area map, of the dynamic reactive compensation equipment serves as movement criteria to formulate a lower-stage control strategy, rapid tracking is achieved, and real-time responses are achieved. By means of the wind-power-integration-responded electrical power system reactive voltage hierarchical control method, the power grid side voltage stability problem caused by wind power integration can be effectively solved, the reasonable coordination control mode can be selected, the operation efficiency and the control efficiency can be improved, and the capacity for the system to response to voltage instability caused by fluctuation of wind power output can be improved.

Description

The power system reactive power voltage hierarchical control method of reply wind-powered electricity generation access

Technical field

The present invention relates to the reactive Voltage Optimum control of electric power system, relate more specifically to a kind of power system reactive power voltage hierarchical control method of tackling wind-powered electricity generation access.

Background technology

Wind generating technology is renewable energy power generation technology comparatively ripe, exploitation on the largest scale.Along with the development of intelligent grid technology, it can make renewable new forms of energy and existing electric power system organically blend, and supports the large-scale application of regenerative resource, and promotes to realize the standardization of " plug and play ".But when large-scale wind is generated electricity by way of merging two or more grid systems and brought benefit, its access exerts a certain influence to system voltage stability.Although configured reactive power compensator in wind energy turbine set, but its regulating power is limited, the grid side voltage stability problem that the randomness of wind power and fluctuation cause still exists.

Wei Xiwen etc. ^[1]proposing is that target function is set up idle work optimization model by system losses, average voltage deviation value and static voltage stability nargin, in order to solve the reactive power optimization problem containing wind energy turbine set.Wang Menglin is in Master's thesis " containing reactive voltage operation and the project study of wind energy turbine set electrical network ", and the variation that associating wind-powered electricity generation is exerted oneself and the relation of change in voltage propose voltage out-of-limit probability level, set up idle work optimization model.Liu Mingbo etc. ^[2]using the action frequency of discrete type control appliance as constraint, taking daylong active loss minimum as target function, carry out dynamic reactive optimization.Liang Jifeng is in Master's thesis " the reactive voltage characteristic based on large-scale wind power access electrical network and control research ", using the magnitude of voltage of the wind energy turbine set access point in regional power grid as judge index, by real-time voltage value and target voltage values are compared, regulate Static and dynamic reactive power compensator to control.Conventional electric power System Reactive Power optimization method, by setting up multiple objective function, uses intelligent algorithm search optimal solution, has but ignored the Harmonic Control between reactive power compensator.In " the reactive voltage characteristic based on large-scale wind power access electrical network and control research ", considered the Harmonic Control between compensation arrangement, but control precision is not good enough, random large, be unfavorable for Optimized Operation.

The list of references relating in literary composition:

[1] Wei Xiwen etc. containing the electrical network multiple target idle work optimization [J] of wind energy turbine set. protecting electrical power system with control .2010, (17): 107-111.

[2] Liu Mingbo etc. take into account the dynamic reactive optimized algorithm [J] of control appliance action frequency constraint. Proceedings of the CSEE .2004,, 24 (3): 34-40.

[3] Qi Linge, Li Yong, Qi Qingru etc. consider the improvement five district figure powerless control method researchs [J] of dynamic reactive compensation device. Shaanxi Power, 2014,42 (2): 5-10.

Summary of the invention

The problem existing for prior art, the invention provides a kind of power system reactive power voltage hierarchical control method operation of power networks efficiency and enhancing grid side voltage stability, the access of reply wind-powered electricity generation that improves.

For solving the problems of the technologies described above, the present invention adopts following technical scheme:

The power system reactive power voltage hierarchical control method of reply wind-powered electricity generation access, comprises step:

Step 1, adopts higher level's control strategy to carry out reactive power compensation to electric power system, and described higher level's control strategy is adopted with the following method and obtained:

Step 1.1 according to prediction wind power data and the electricity situation of exerting oneself, obtains the reactive voltage data of grid side test point under electrical network normal operation, and described reactive voltage data comprise test point magnitude of voltage and idle output;

Step 1.2, falls into region in the improvement five district figure that control obtain corresponding control mode according to reactive voltage data corresponding points higher level, if reactive voltage data corresponding points fall into dynamic reactive active region, obtains after corresponding multiple control modes execution step 1.3; In the improvement five district figure that higher level controls, " 0 " district voltage range is set within the scope of the permissible variation of busbar voltage;

Step 1.3, according to the system relevant parameter of wind-powered electricity generation access and prediction wind power data, action frequency reactive power reserve minimum and dynamic reactive compensation device with discrete type reactive apparatus is target function to the maximum, set constraints, use intelligent algorithm to carry out optimizing, in the multiple control modes obtaining in step 1.2, select the control mode satisfying condition;

Step 1.4, the control mode that operation satisfies condition in electric power system, and judge whether the rear each node reactive voltage data corresponding points of operation all drop on the non-dynamic idle active region in improvement five district figure " 0 " districts of higher level's control, if so, using this control mode as higher level's control strategy; Otherwise repeating step 1.1～1.4, until obtain higher level's control strategy;

Step 2 is moved higher level's control strategy in the time of the electric power system of wind power injection in real time, and judges that whether the reactive voltage data corresponding points of grid side test point fall into improvement five district figure " 0 " districts that subordinate controls, if fall into " 0 " district, only move higher level's control strategy; Otherwise, in operation higher level control strategy, adopt dynamic reactive compensation device to carry out reactive power compensation, until the reactive voltage data corresponding points of grid side test point fall into improvement five district figure " 0 " districts that subordinate controls, improvement five district figure " 0 " the district voltage ranges of higher level's control are set and be greater than to improvement five district figure " 0 " the district voltage ranges that subordinate controls within the scope of the permissible variation of busbar voltage.

Step 1.3 is specially:

Initialization intelligent algorithm, and input the system relevant parameter of wind-powered electricity generation access and predict wind power data;

Offered target function and constraints, constraints comprises electric power system internal constraint condition and dynamic reactive compensation device reactive power reserve ratio constraints, and described target function and dynamic reactive compensation device reactive power reserve ratio constraints are as follows:

$\left\{\begin{array}{c}\min f_1=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{N}_{\mathrm{ij}}\\ \min f_2=\left\{\begin{array}{c}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{Q_j^{\&prime;}}{Q_{j\max }},Q_j^{\&prime;}>0\\ \underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{Q_j^{\&prime;}}{Q_{j\min }},Q_j^{\&prime;}<0*\end{array}\right.\\ k_{1\min }<\frac{|Q_{j\min }-Q_j^{\&prime;}|}{\left|Q_{j\min }\right|}<k_{1\max }\\ k_{2\min }<\frac{Q_{j\max }-Q_j^{\&prime;}}{Q_{j\max }}<k_{2\max }\end{array}\right.---\left(1\right)$

Wherein, m represents the quantity of configured website, and j represents site number; N represents the quantity of the discrete type reactive apparatus of each site configuration, and i represents the numbering of the discrete type reactive apparatus of configuration in each station; N _ijfor the action frequency of discrete type reactive apparatus; Q' _jrepresent the real-time idle output of the dynamic reactive compensation device of website j; Q _jmaxrepresent the dynamic passive compensation capacitive total capacity of website j, Q _jminrepresent the dynamic passive compensation perception total capacity of website j, Q _jmaxand Q _jmindetermine according to the dynamic reactive capacity of site configuration; k _1max, k _1minrepresent that respectively dynamic reactive compensation device perception reactive power reserve accounts for dynamic passive compensation perception total capacity Q _jminthe upper and lower bound of ratio; k _2max, k _2minrepresent that respectively dynamic reactive compensation device capacitive reactive power reserve capacity accounts for dynamic passive compensation capacitive total capacity Q _jmaxthe upper and lower bound of ratio; k _1max, k _1min, k _2max, k _2minbe empirical value;

In the multiple control modes that operation intelligent algorithm obtains in step 1.2, select the control mode satisfying condition.

Above-mentioned intelligent algorithm is classical genetic algorithm.

For solving the fluctuation of wind power and the voltage stability problem that randomness causes, many-side of the present invention has been considered regulating characteristics, response speed and the switching mode of reactive-load compensation equipment, for the reactive voltage characteristic of wind energy turbine set access electrical network, select rational coordinated control mode, improve operation and control efficiency, the ability of the Voltage Instability problem that the fluctuation that enhancing system reply wind power is exerted oneself causes.

Compared to the prior art, the present invention has the following advantages:

(1) based on improving five district figure, and propose higher level and control and subordinate control, make static passive compensation device and dynamic reactive compensation device cooperation, in effectively reducing static passive compensation device action frequency, improve dynamic reactive compensation device utilance, take into account the coordination control of voltage security and reactive power compensation assembling device, improved the Voltage Instability problem being caused by randomness and the fluctuation of output of wind electric field.

(2) control mode is flexible, meets the reactive power/voltage control requirement under intelligent grid background.

(3) by indexs such as average active power loss rate, maximum active power loss rate, static passive compensation device and regulator action frequencies before and after comparison grading control, show that the voltage grading control effect that the present invention is based on the reactive voltage hierarchical control method that improves five district figure is better than traditional reactive voltage hierarchical control method based on nine district figure.

Brief description of the drawings

Fig. 1 is the particular flow sheet of the inventive method;

Fig. 2 is the schematic diagram that improves five district figure;

Fig. 3 improves " 0 " district schematic diagram of five district figure in upper and lower level;

Fig. 4 is 3 machine 9 node system figure of wind-powered electricity generation access;

The each node voltage p.u. of system change curve when Fig. 5 is reactive power compensation and voltage-regulation;

Fig. 6 is each node voltage perunit value change curve of controlling through higher level;

Fig. 7 is each node voltage perunit value change curve of controlling through subordinate;

Fig. 8 is maximum active power loss rate before and after scheme one, two is controlled, and wherein, scheme one is the reactive voltage grading control strategy based on improving five district figure; Scheme two is traditional nine district figure;

Fig. 9 is that scheme one, two is controlled forward backward averaging active power loss rate.

Embodiment

The grid side voltage stability problem causing for fluctuation and the randomness of wind power, the present invention is based on the new method of improving five district figure and proposed a kind of power system reactive power voltage grading control of tackling wind-powered electricity generation access, the method proposes the hierarchical control method that comprises higher level's control strategy and subordinate's control strategy.Higher level's control strategy is to formulate for the grid side voltage fluctuation that inhibition wind power fluctuation causes, it is according to prediction wind power relevant data, utilize static passive compensation device and dynamic reactive compensation device to control, be the major part of hierarchical control method of the present invention, its control mode will affect entirety and control effect.Prediction wind power refers to the possible power output of wind energy turbine set of obtaining according to wind-powered electricity generation Predicting Technique, wind power is the power output of wind energy turbine set reality in real time, due to the error of prediction wind power and real-time wind power, control effect may cause higher level's control strategy to apply to real-time condition time is lower than Expected Results, formulate subordinate's control strategy for this situation, subordinate's control strategy is to utilize dynamic reactive compensation device to control, to utilize dynamic reactive compensation device to coordinate compensation on higher level's control strategy basis, in order to improve control precision, strengthen the ability of electric power system reply voltage out-of-limit problem.In the time only adopting higher level's control strategy can tackle the reactive voltage stability problem of grid side, do not enable subordinate's control strategy; Otherwise, enable.

Further illustrate technical solution of the present invention below in conjunction with the drawings and specific embodiments, see Fig. 1, concrete steps are as follows:

Higher level's control strategy of step 1, reply wind power fluctuation.

This step comprises two parts:

(1) obtain multiple control modes based on improving five district figure

For the grid side reactive voltage stability problem that reply wind power fluctuation causes, the reactive voltage delta data of the grid side that known prediction wind power injects, adopts Qi Lin pavilion etc. ^[3]the improvement five district figure that propose, as reactive power/voltage control strategy, are shown in Fig. 2, and U represents grid side reactive voltage value, and Q represents the idle output of grid side.In figure, " 0 " district is stable region, i.e. ABCD region, if grid side reactive voltage value drops on " 0 " district, reactive power compensator is failure to actuate; " 1 " district is shift-up action district, i.e. C ₀cDD ₀region, upgrades and refers to and will have the tap that carries transformer to upgrade; " 2 " district is shift-down action district, i.e. B ₀bAA ₀region, lowers category and refers to and will have the tap that carries transformer to lower category; " 3 " district is for dropping into capacitor area, i.e. A ₀aDD ₀region; " 4 " district is excision capacitor area, i.e. B ₀bCC ₀region; Dotted line institute region, be that in Fig. 2, shadow region is dynamic reactive active region, in shadow region and each area overlapping region, can enable separately static passive compensation device, can enable separately again dynamic reactive compensation device, also can use static passive compensation device and dynamic reactive compensation device to coordinate compensation, that is, the reactive voltage value of grid side drops in dotted line and each area overlapping region will multiple control modes simultaneously.Here, grid side reactive voltage value is determined by the output of grid side observation station.

(2) adopt classical genetic algorithm from multiple control modes, to choose optimal control mode as higher level's control strategy.

In the time that the reactive voltage value of grid side drops in Fig. 2 non-hatched area, carry out compensating operation corresponding to this region, the higher level's control strategy obtaining; If while dropping in Fig. 2 shadow region, to produce multiple control modes, for example, reactive voltage value falls into the shadow region in Fig. 2 " 3 " district, can only carry out and drop into electric capacity, only carry out dynamic passive compensation or carry out input electric capacity and dynamic passive compensation simultaneously, now need to adopt classical genetic algorithm from multiple control modes, to choose optimal control mode.

For improving control efficiency and operational efficiency, give full play to the performance of static passive compensation device and dynamic reactive compensation device, be held under the prerequisite in limited field in guarantee system voltage horizontal dimension, need to from multiple control modes, choose Optimal Control mode as higher level's control strategy, higher level's control strategy of choosing need meet the action frequency that at utmost reduces discrete type reactive apparatus, i.e. f ₁minimum; At utmost increase the reactive power reserve of dynamic reactive compensation device, i.e. f ₂minimum, see formula (1):

$\left\{\begin{array}{c}\min f_1=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{N}_{\mathrm{ij}}\\ \min f_2=\left\{\begin{array}{c}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{Q_j^{\&prime;}}{Q_{j\max }},Q_j^{\&prime;}>0\\ \underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{Q_j^{\&prime;}}{Q_{j\min }},Q_j^{\&prime;}<0*\end{array}\right.\\ k_{1\min }<\frac{|Q_{j\min }-Q_j^{\&prime;}|}{\left|Q_{j\min }\right|}<k_{1\max }\\ k_{2\min }<\frac{Q_{j\max }-Q_j^{\&prime;}}{Q_{j\max }}<k_{2\max }\end{array}\right.---\left(1\right)$

In formula (1):

M represents the quantity of configured website, and j represents site number; N represents the quantity of the discrete type reactive apparatus of each site configuration, the discrete type reactive apparatus quantity of each site configuration is not necessarily identical, discrete type reactive apparatus comprises static passive compensation device and regulator, and i represents the numbering of the discrete type reactive apparatus of configuration in each station; N _ijfor the action frequency of discrete type reactive apparatus, N _ijinitial value is 0, when discrete type reactive apparatus moves once, and N _ijadd 1;

Q' _jrepresent the real-time idle output of the dynamic reactive compensation device of website j; Q _jmaxrepresent the dynamic passive compensation capacitive total capacity of website j, Q _jminrepresent the dynamic passive compensation perception total capacity of website j, Q _jmaxand Q _jmindetermine according to the dynamic reactive capacity of site configuration;

K _1max, k _1minrepresent that respectively dynamic reactive compensation device perception reactive power reserve accounts for dynamic passive compensation perception total capacity Q _jminthe upper and lower bound of ratio; k _2max, k _2minrepresent that respectively dynamic reactive compensation device capacitive reactive power reserve capacity accounts for dynamic passive compensation capacitive total capacity Q _jmaxthe upper and lower bound of ratio; k _1max, k _1min, k _2max, k _2minbe empirical value.

In formula (1), equation is the target function of determining higher level's control strategy scheme, and inequality is corresponding constraints.

For improving control efficiency, realize Optimized Operation, the control mode of discrete type reactive apparatus will can not change after determining in subordinate's control strategy.Higher level's control strategy is to provide grid side fundamental voltage to be supported for main principle, and concrete implementation step is as follows:

Step 1.1 according to prediction wind power data and generator output situation, is obtained the reactive voltage data of grid side test point under electrical network normal operation.Reactive voltage data are the reactive voltage value of grid side, and prediction wind power data is known.

Step 1.2, based on reactive voltage data, the improvement five district figure of higher level control obtain power system reactive power voltage control mode as operating criterion, when reactive voltage data corresponding points fall into the dynamic reactive active region that improves five district figure, can obtain multiple control modes, now, execution step 1.3.In this concrete enforcement, the voltage range in improvement five district figure " 0 " districts that higher level controls is made as 0.93p.u～1.07p.u, the permissible variation value that the voltage range in " 0 " district is busbar voltage here.

Step 1.1 and step 1.2 Dynamic Execution, when in step 1.2 during according to reactive voltage data judging control method, step 1.1 item continues to obtain current reactive voltage data.

Step 1.3, taking equation in formula (1) as target function, taking inequality and electric power system internal constraint as constraints, adopts classical genetic algorithm (GA) from multiple control modes, to select Optimal Control mode.Described electric power system internal constraint comprises power-balance, node voltage constraint, the constraint of power plant Power generation limits and system load flow profile constraints.

Step 1.3 further comprises sub-step:

The system relevant parameter of step 1.3a input wind-powered electricity generation access and prediction wind power data, initialization genetic algorithm, comprises initial population size, crossover probability, variation probability and greatest iteration algebraically is set.The system relevant parameter of wind-powered electricity generation access mainly comprises the meritorious idle data in NETWORK STRUCTURE PRESERVING POWER SYSTEM parameter, Real-time Load power data and power plant etc.

Step 1.3b, based on target function in formula (1) and constraints, chooses the control mode satisfying condition from multiple control modes.

Step 1.4, the control mode satisfying condition that operating procedure 1.3 obtains in electric power system, and judge after operation whether each node reactive voltage data corresponding points all drop on higher level and control the non-hatched area in " 0 " district of improving five district figure, if,, using this control mode as higher level's control strategy, finish optimizing; Otherwise, repeating step 1.1～1.4.

Above-mentioned classical genetic algorithm (GA) can adopt other intelligent algorithms to replace, for example, and simulated annealing, particle cluster algorithm etc.

Subordinate's control strategy of step 2, reply wind power randomness.

Step 1 is obtained to higher level's control strategy and move in the electric power system of actual wind power injection, and judge that whether grid side reactive voltage value corresponding points fall into improvement five district figure " 0 " districts that subordinate controls, if fall into, only move higher level's control strategy; Otherwise operation falls into subordinate's control strategy of a region in operation higher level control strategy.

The voltage out-of-limit problem that may cause for the error of prediction wind power and actual wind power, subordinate's control strategy will make full use of continuous, quick, the electrodeless regulating characteristics of dynamic reactive compensation device, to improve dynamic reactive compensation device operating space in five district figure (being dotted line institute region in Fig. 2) as judging district.Higher level's control strategy is to provide fundamental voltage to be supported for main principle, and it is the strictest to voltage and idle restriction, and " 0 " district area of corresponding improvement five district figure is made as minimum, as quadrangle A'B'C'D' institute region in Fig. 3.Subordinate's control strategy is that to tackle the voltage out-of-limit problem that the error of prediction wind power and actual wind power causes be main principle, and " 0 " district of its correspondence is as solid line quadrangle ABCD institute region in Fig. 3.

Accomplish to follow the tracks of fast and real-time response by the compensation characteristic of dynamic reactive compensation device, subordinate's control strategy possesses voltage out-of-limit and the reactive power imbalance problem that effective solution is caused by the randomness of wind speed and other disturbances, and the ability of reactive power support is provided, implementation step is:

Step 2.1 is moved higher level's reactive power compensator compensating movement that higher level's control strategy is formulated in the time that real-time wind power injects electric power system.

Step 2.2, in higher level's reactive power compensator compensating movement, judges whether grid side reactive voltage value falls into improvement five district figure " 0 " districts that subordinate controls; If fall into " 0 " district, continue operation higher level reactive power compensator compensating movement; Otherwise in operation higher level reactive power compensator compensating movement, operation state reactive power compensator carries out reactive power compensation, until reactive voltage value falls into improvement five district figure " 0 " districts that subordinate controls.In this concrete enforcement, improvement five district figure " 0 " the district voltage ranges that subordinate controls are made as 0.9p.u～1.1p.u, here " 0 " district voltage range is slightly larger than subordinate and controls " 0 " district voltage range of improving five district figure, specifically sets according to the permissible variation value of busbar voltage.

Embodiment

For checking the inventive method is tackled the validity of the regulating power of wind-powered electricity generation access, 33 wind energy turbine set that dual-feed asynchronous wind power generator forms that the unit that in standard 3 machine 9 node systems, node 2 accesses is replaced to installed capacity is 99MW, be 1.5MW by single-machine capacity, see Fig. 4, wherein represent on-load tap-changing transformer No. 1 and No. 2.The reactive power compensator of No. 1 on-load tap-changing transformer low-pressure side installing comprises: 4 group capacitor groups and TCR type SVC; No. 2 on-load tap-changing transformer low-pressure side is installed 4 group capacitor groups.Voltage limited range in improvement corresponding higher level's control strategy five district figure is made as to 0.93-1.07p.u.; In improvement five district figure corresponding to subordinate's control strategy, voltage limited range is made as 0.9-1.1p.u..Utilize typical genetic algorithm to calculate, initial population size is made as 100, and crossover probability is made as 0.85, and variation probability is made as 0.15, and greatest iteration algebraically is made as 500.

Dope force data according to wind energy turbine set, in the situation that not carrying out reactive power compensation and voltage-regulation, the change curve of each node voltage (perunit value) is known as shown in Figure 5 in system, and when output of wind electric field is larger, the each node voltage level of system declines and lower than lower limit 0.9p.u. thereupon; Output of wind electric field is less, and the each node voltage level of system increases and higher than higher limit 1.1p.u.

For guaranteeing that voltage levvl reaches in prescribed limit, reactive power compensator and voltage regulating device are coordinated to control, according to the idle configuring condition of hierarchical structure data and each website, to improve accordingly five district figure as operational motion criterion, utilize classical genetic algorithm from multiple control modes, to choose optimal control mode as higher level's control strategy, and go out to carry out under force data actual, each node voltage (perunit value) is shown in Fig. 6, as can be seen from Figure 6, under actual wind power, carry out after higher level's control strategy, most node voltages are in limited range, but minority node voltage is still out-of-limit within a period of time.

Part of nodes voltage out-of-limit problem under the higher level's control strategy being caused by the randomness of wind power, enable subordinate's control strategy, after being finished, the change curve of each node voltage (perunit value) is shown in Fig. 7, as can be seen from Figure 7, by enabling subordinate's control strategy, node voltage is controlled in safe range.

For access control effect, scheme one is expressed as to voltage hierarchical control method of the present invention, scheme two is expressed as traditional nine district figure, when Fig. 8, Fig. 9 and table 1 have provided respectively employing scheme one and scheme two are in the scope that each system node voltage is adjusted to regulation, the action frequency of on-load transformer tap changer and capacitor group switching in the maximum active power loss rate in control front and back, average active power loss rate and control procedure.

As shown in Figure 8, controlling the maximum active power loss rate of front system is 0.023; Employing scheme one, the maximum active power loss rate of system reduces to 0.015, and the Network Loss Rate of minimizing is 0.008; Employing scheme two, the maximum active power loss rate of system reduces to 0.021, and the network loss amount of minimizing is 0.002.

As shown in Figure 9, before control, the average active power loss rate of system is 0.0144; Employing scheme one, the average active power loss rate of system reduces to 0.0116, and the Network Loss Rate of minimizing is 0.0028; Employing scheme two, the average active power loss rate of system reduces to 0.0131, and the Network Loss Rate of minimizing is 0.0013.

Result shows, employing scheme one has reduced active power loss, better economy.

Correction data from table 1 can learn, adopts grading control strategy based on improving five district figure can effectively reduce the action frequency of tap and capacitor group, avoided the phenomenon such as frequent movement, throw in-of oscillation.

Table 1 scheme one, two devices action frequency Statistical Comparison

Claims (3)

1. the power system reactive power voltage hierarchical control method of reply wind-powered electricity generation access, is characterized in that, comprises step:

Step 1, adopts higher level's control strategy to carry out reactive power compensation to electric power system, and described higher level's control strategy is adopted with the following method and obtained:

Step 1.1 according to prediction wind power data and the electricity situation of exerting oneself, obtains the reactive voltage data of grid side test point under electrical network normal operation, and described reactive voltage data comprise test point magnitude of voltage and idle output;

Step 1.2, falls into region in the improvement five district figure that control obtain corresponding control mode according to reactive voltage data corresponding points higher level, if reactive voltage data corresponding points fall into dynamic reactive active region, obtains after corresponding multiple control modes execution step 1.3; In the improvement five district figure that higher level controls, " 0 " district voltage range is set within the scope of the permissible variation of busbar voltage;

Step 1.3, according to the system relevant parameter of wind-powered electricity generation access and prediction wind power data, action frequency reactive power reserve minimum and dynamic reactive compensation device with discrete type reactive apparatus is target function to the maximum, set constraints, use intelligent algorithm to carry out optimizing, in the multiple control modes obtaining in step 1.2, select the control mode satisfying condition;

Step 1.4, the control mode that operation satisfies condition in electric power system, and judge whether the rear each node reactive voltage data corresponding points of operation all drop on the non-dynamic idle active region in improvement five district figure " 0 " districts of higher level's control, if so, using this control mode as higher level's control strategy; Otherwise repeating step 1.1～1.4, until obtain higher level's control strategy;

Step 2 is moved higher level's control strategy in the time of the electric power system of wind power injection in real time, and judges that whether the reactive voltage data corresponding points of grid side test point fall into improvement five district figure " 0 " districts that subordinate controls, if fall into " 0 " district, only move higher level's control strategy; Otherwise, in operation higher level control strategy, adopt dynamic reactive compensation device to carry out reactive power compensation, until the reactive voltage data corresponding points of grid side test point fall into improvement five district figure " 0 " districts that subordinate controls, improvement five district figure " 0 " the district voltage ranges of higher level's control are set and be greater than to improvement five district figure " 0 " the district voltage ranges that subordinate controls within the scope of the permissible variation of busbar voltage.

2. the power system reactive power voltage hierarchical control method of reply wind-powered electricity generation access as claimed in claim 1, is characterized in that:

Step 1.3 is specially:

Initialization intelligent algorithm, and input the system relevant parameter of wind-powered electricity generation access and predict wind power data;

Offered target function and constraints, constraints comprises electric power system internal constraint condition and dynamic reactive compensation device reactive power reserve ratio constraints, and described target function and dynamic reactive compensation device reactive power reserve ratio constraints are as follows:

$\left\{\begin{array}{c}\min f_1=\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}{N}_{\mathrm{ij}}\\ \min f_2=\left\{\begin{array}{c}\underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{Q_j^{\&prime;}}{Q_{j\max }},Q_j^{\&prime;}>0\\ \underset{j=1}{\overset{m}{\mathrm{\&Sigma;}}}\frac{Q_j^{\&prime;}}{Q_{j\min }},Q_j^{\&prime;}<0*\end{array}\right.\\ k_{1\min }<\frac{|Q_{j\min }-Q_j^{\&prime;}|}{\left|Q_{j\min }\right|}<k_{1\max }\\ k_{2\min }<\frac{Q_{j\max }-Q_j^{\&prime;}}{Q_{j\max }}<k_{2\max }\end{array}\right.---\left(1\right)$

Wherein, m represents the quantity of configured website, and j represents site number; N represents the quantity of the discrete type reactive apparatus of each site configuration, and i represents the numbering of the discrete type reactive apparatus of configuration in each station; N _ijfor the action frequency of discrete type reactive apparatus; Q' _jrepresent the real-time idle output of the dynamic reactive compensation device of website j; Q _jmaxrepresent the dynamic passive compensation capacitive total capacity of website j, Q _jminrepresent the dynamic passive compensation perception total capacity of website j, Q _jmaxand Q _jmindetermine according to the dynamic reactive capacity of site configuration; k _1max, k _1minrepresent that respectively dynamic reactive compensation device perception reactive power reserve accounts for dynamic passive compensation perception total capacity Q _jminthe upper and lower bound of ratio; k _2max, k _2minrepresent that respectively dynamic reactive compensation device capacitive reactive power reserve capacity accounts for dynamic passive compensation capacitive total capacity Q _jmaxthe upper and lower bound of ratio; k _1max, k _1min, k _2max, k _2minbe empirical value;

In the multiple control modes that operation intelligent algorithm obtains in step 1.2, select the control mode satisfying condition.

3. the power system reactive power voltage hierarchical control method of reply wind-powered electricity generation access as claimed in claim 1, is characterized in that:

Described intelligent algorithm is classical genetic algorithm.