CN107959301A

CN107959301A - Low-voltage network distributed energy storage containing photovoltaic is distributed rationally and operation method

Info

Publication number: CN107959301A
Application number: CN201711272249.8A
Authority: CN
Inventors: 林舜江; 何森; 卢苑; 刘明波; 段力勇
Original assignee: South China University of Technology SCUT; Research Institute of Southern Power Grid Co Ltd
Current assignee: South China University of Technology SCUT; CSG Electric Power Research Institute; Research Institute of Southern Power Grid Co Ltd
Priority date: 2017-12-06
Filing date: 2017-12-06
Publication date: 2018-04-24
Anticipated expiration: 2037-12-06
Also published as: CN107959301B

Abstract

Distributed rationally the invention discloses a kind of low-voltage network distributed energy storage containing photovoltaic and operation method, this method include：Respectively determine DES total rated power and whole LVDN needed for DES total specified electric quantity；Structure DES is distributed rationally and moving model；DES is distributed rationally and is solved with moving model, obtain LVDN in DES distribute rationally and operating scheme.This method is first according to allowing node voltage the requirement of offset come the total rated power of DES needed for determining whole LVDN and total specified electric quantity, then construct and target is up to higher level's load rate of grid, consider the Optimized model of the installation points limitation of DES in supporting role and LVDN of the voltage ＆ var control characteristic of DES to LVDN voltages, optimum results show that proposed Optimized model can be to the installation site of DES, rated power, the charging and discharging state and power of specified electric quantity and day part are carried out at the same time Optimal Decision-making, the active loss of power grid can be also set to obtain a degree of reduction while being optimized to higher level's load rate of grid.

Description

Low-voltage network distributed energy storage containing photovoltaic is distributed rationally and operation method

Technical field

The present invention relates to technical field of electric power, and in particular to a kind of low-voltage network distributed energy storage optimization containing photovoltaic is matched somebody with somebody Put and operation method.

Background technology

At present, China's low-voltage network (low-voltage distribution network, abbreviation LVDN) mainly with Radial communication network structure is run, and since distribution line is longer, more than load species and increases fast, is easy to cause distribution line loss Greatly, feeder terminal low voltage, higher level's network load fluctuate the problems such as big.Protected with the change of China's energy resource structure and to environment Desired raising is protected, permeability of the distributed photovoltaic in LVDN is continuously increased, its output is influenced by intensity of illumination and temperature And there is larger random fluctuation so that the change of distribution Running State is frequent, and the safe operation to power distribution network brings very big challenge. Since distributed energy storage (Distributed energy storage, vehicle economy S) can coordinate power generation and coulomb balance, realize Both Dynamic Matchings, and possess peak load shifting, improve quality of voltage, reduce network loss, stabilize power swing, delay power grid dilatation The functions such as investment, have very big application prospect in the LVDN containing distributed photovoltaic.But DES is in manufacture, operation and dimension at present How shield etc. price costly, to realize DES distributing rationally in LVDN and run, and there is an urgent need for propose effective solution party Method.

At present, existing the research usual only installation site to energy storage, the specified work(distributed rationally to DES with operation problem The one side therein such as rate, specified electric quantity, charging and discharging state and power optimizes, and is given in advance to other aspect information 's.In addition, existing Optimized model is usually with active loss minimum, the configuration of DES and economical operation benefit maximum of power grid etc. Solved for object function, seldom consider influence of the voltage ＆ var control characteristic of DES for LVDN voltages.

Above-mentioned technology has the drawback that：The existing research distributed rationally to DES with operation problem is rare while considers Optimization to the installation site of energy storage, rated power, specified electric quantity, charging and discharging state and power, only research are distributed rationally or excellent Change in operation problem in a certain respect, and be given in advance to other aspect information, as a result with certain subjectivity.Together When, study supporting role of the voltage ＆ var control characteristic of also rare consideration DES to LVDN voltages, and rare consideration LVDN The installation points limitation of middle DES, optimum results and Practical Project demand gap are larger.

The content of the invention

It is an object of the invention to overcome above-mentioned the deficiencies in the prior art, there is provided a kind of low-voltage network distribution containing photovoltaic Formula energy storage is distributed rationally and operation method, can also make the active of power grid while being optimized to higher level's load rate of grid Loss obtains a degree of reduction.

To achieve the above object, the technical scheme is that：

Low-voltage network distributed energy storage containing photovoltaic is distributed rationally and operation method, the described method includes：

Respectively determine DES total rated power and whole LVDN needed for DES total specified electric quantity；

Structure DES is distributed rationally and moving model

The DES is distributed rationally with moving model using higher level's load rate of grid as object function, such as formula (3)：

In formula, P_grid,tRepresent the period t higher level's power grid injection LVDN total active power, max { } represent to one day 24 Period higher level's power grid injection LVDN is always active to be maximized；

The DES is distributed rationally and is solved with moving model, obtain LVDN in DES distribute rationally and operating scheme

Using minimize always inject active variance replace maximizing rate of load condensate as target the DES is distributed rationally and Moving model is solved, this always injects the expression formula such as formula (4) of active variance：

In formula, P_grid,tRepresent total active power of period t higher level's power grid injection LVDN.

The total rated power ripple of the definite DES includes the following steps：

S11, the fluctuation range contributed according to photovoltaic, account for the optimal load flow calculating that photovoltaic goes out fluctuation, obtain The magnitude of voltage of the minimum node of voltage and corresponding photovoltaic is contributed at this time in LVDN；

S12, account for the optimal load flow calculating that photovoltaic goes out fluctuation, obtains the magnitude of voltage of voltage highest node in LVDN Corresponding photovoltaic is contributed at this time；

S13, judge two kinds of photovoltaic output scene lower node minimum voltages of above-mentioned steps S11, S12 and ceiling voltage whether It is out-of-limit；

In step S11 and S12, the optimal load flow computation model of use is respectively such as formula (1) and (2)

In formula, V_L,minAnd V_H,maxRepresent the minimum node of voltage and voltage highest node in corresponding photovoltaic output scene respectively Under magnitude of voltage, the minimum node of voltage and voltage highest node are obtained by the Load flow calculation under photovoltaic output desired value scene；Deng Formula constrains g_L() and g_H() is illustrated respectively under the minimum and highest scene of node voltage, the work(of each node in system Rate equilibrium equation；V_LAnd V_HRepresent the voltage of each node under two kinds of scenes；θ_LAnd θ_HRepresent the voltage phase of each node under two kinds of scenes Angle；P_L,gridAnd P_H,gridRepresent total active power of higher level's power grid injection LVDN under two kinds of scenes；P_grid,maxAnd P_grid,minPoint Not Biao Shi higher level's power grid injection the total active power of LVDN upper and lower limit；P_L,pvAnd P_H,pvRepresent that corresponding photovoltaic goes out under two kinds of scenes Power.P_pv,maxAnd P_pv,minThe upper and lower limit of photovoltaic active power output is represented respectively；Distributed photovoltaic use power factor permanent for 1 control The idle output of mode processed, i.e. photo-voltaic power supply is zero；

In step S13, photovoltaic when node voltage is in qualified critical value is contributed to be obtained by Load flow calculation, its In, photovoltaic is contributed as unknown quantity, if containing multiple photovoltaic nodes in LVDN, the active power output of all photovoltaic nodes is in the phase Fluctuated on the basis of prestige value according to same ratio, while using the voltage magnitude of all photovoltaic nodes as unknown quantity, that is, be equal to and close Lattice critical value, thus unknown quantity number is equal with equation number, power flow equation can solve.

The total specified electric quantity for determining DES needed for whole LVDN includes the following steps：

S101, minimum photovoltaic output under carry out one day 24 when discontinuity surface Load flow calculation, draw LVDN in one day 24h There are all moment that node voltage gets over lower limit；

S102, progress of each moment Load flow calculation that lower limit is got over to voltage, must send as an envoy to each minimum node of moment voltage The photovoltaic that magnitude of voltage just reaches corresponding when calculating standard value is contributed, and calculates the photovoltaic output that all voltages get over the lower limit moment The difference contributed with minimum photovoltaic and summation；

S103, maximum photovoltaic output under carry out one day 24 when discontinuity surface Load flow calculation, draw LVDN in one day 24h There are all moment that node voltage gets over the upper limit；

S104, each moment to Over High-Limit Voltage carry out Load flow calculation, and must send as an envoy to each moment voltage highest node Magnitude of voltage is just down to photovoltaic corresponding when calculating standard value and contributes, and the photovoltaic for calculating all Over High-Limit Voltage moment is contributed The difference contributed with maximum photovoltaic and summation；

S105, take the higher value of result of calculation in above-mentioned steps S102 and S104 as total specified electric quantity of required DES.

The DES is distributed rationally includes following constraints with moving model：Node power Constraints of Equilibrium, voltage bound Constraint, system safety operation constraint, the installation number constraint of energy storage, energy storage total rated power and total specified Constraint, energy storage Charge-discharge electric power constraint, the remaining capacity constraint of energy storage, the voltage power-less characteristic constraint of energy storage.

The node power Constraints of Equilibrium is：

It is as follows for the node that voltage class in LVDN is 380V, power balance equation：

It is as follows for distribution transforming both high side node 22, power balance equation：

In formula,Represent the active power output of period t node i photovoltaic；WithPeriod t node i DES is represented respectively Charge and discharge power, it is assumed that the active power output of DES is just during electric discharge, and the active power output of DES is negative during charging；By storage below The bound constraint of energy charge-discharge electric power is understood, is fitted without DES when the DES of some candidate in optimum results installs node, then should NodeWithAll will be 0.Represent the active power of period t node i load；And V_j,tPeriod t section is represented respectively The voltage magnitude of point i and node j；θ_ij,tRepresent the phase difference of voltage between period t node i, j；G_ijAnd B_ijNode is represented respectively The real and imaginary parts of i-th row jth column element in admittance matrix；Represent the reactive power of period t node i load；Q_grid,tTable Show total reactive power of period t higher level's power grid injection LVDN,Represent the idle output of photovoltaic of period t node i；Represent The reactive power of the energy storage injection power distribution network of period t node i.N is the node total number of LVDN；Hop count when T is, during using 1h as one Section, one day totally 24 period.

The voltage bound is constrained to：

Each node voltage all should be as follows in acceptability limit when LVDN is run：

V_min≤V_i,t≤V_max \*MERGEFORMAT(9)

In formula, V_minAnd V_maxThe lower and upper limit of node voltage are represented respectively；

The system safety operation is constrained to：

Distribution transformer does not answer overlond running, and the apparent energy for flowing through distribution transforming is necessarily less than capacity of distribution transform, as follows：

In formula, S_TRepresent the rated capacity of distribution transformer.

The installation number of the energy storage is constrained to:

The installation number of nodes of DES should not be excessive in LVDN, tackles it and is defined, as follows：

In formula, S_ESRepresent the DES installation node sets of candidate, N_maxRepresent the maximum number for allowing the DES of access in LVDN Amount；In the application in addition to distribution transformer high-pressure side node, DES of other nodes as candidate in LVDN installs node； When by distribution transformer high-pressure side node compile be N nodes when, then the DES of candidate installs node set S_ES={ 1,2 ..., N- 1}；Sign functionMathematic(al) representation it is as follows：

According to formula (12), when candidate installs the energy storage rated power of nodeDuring more than 0, then the node needs to install storage Energy；When candidate installs the energy storage rated power of nodeDuring equal to 0, then the node is not required to installation energy storage.

The energy storage total rated power and total specified Constraint are:

The DES rated power of DES installation nodes and the summation of specified electric quantity of all candidates should be respectively equal in power distribution network Required DES total rated powers and total specified electric quantity, it is as follows：

In formula,WithThe rated power and specified electric quantity of node i DES, P are represented respectively_ESAnd E_ESRepresent respectively DES total rated powers needed for LVDN and total specified electric quantity；In order to avoid there is some node in result of calculationAndSituation, sign function is used in formula (14)It is multiplied byAs long as so that some nodeRepresent The node is not required to installation DES, then the DES specified electric quantities of the node are also 0 in the composition of total specified electric quantity EES；

The energy storage charge-discharge electric power is constrained to:

Any time period t of energy storage device in operation, can be only in charge or discharge state, and the power of discharge and recharge is big It is small to be not to be exceeded its rated value, it is as follows：

From formula (15) and (16), when the DES installation nodes of some candidate in optimum results are not chosen as installation section Point, the i.e. candidate install the energy storage rated power of nodeDuring equal to 0, the charge and discharge power of the DES of the nodeWith All will be 0.

The remaining capacity of the energy storage is constrained to:

It is assumed that the initial residual electricity of energy-storage units is the 50% of specified electric quantity, for any one during storage energy operation A moment t, its remaining capacity are as follows no more than specified electric quantity：

In formula,Represent the initial quantity of electricity of node i DES；η_cAnd η_dThe charge and discharge efficiency of DES is represented respectively；Δ t is represented The time interval of one period, is 1h；

The voltage power-less characteristic constraint of the energy storage:

The idle and voltage of energy storage is as follows using traditional droop control characteristic, expression formula：

In formula, n_QRepresent the sagging coefficient of voltage, be the constant between 0 to 1；V₀Represent energy storage REACTIVE POWER/VOLTAGE droop characteristic Voltage initial value, its perunit value are taken as 1；Sign function is multiplied by the right of equationExpression is only chosen as in optimum results DES installations node just can inject reactive power there are energy storage device to power distribution network

Smoothing to sign function in constraint equation is handled：

Constraint equation (11), (14) and (20) contains sign function, due to sign function sgn (x) at x=0 not Continuously, difficulty will greatly increase when above-mentioned Optimized model solves directly in GAMS softwares, if can be converted into sign function Continuous function, the solution difficulty of model will substantially reduce, it is therefore necessary to find another continuous function and carry out close approximation Sign function, the function can continuously be led at x=0, in view of the image shape and symbol of s type functions, that is, sigmoid functions Function sgn (x) is similar, and rationally deformation is carried out to sigmoid functions can approach sign function, as shown in formula (21)：

In formula, μ is the abrupt slope constant of s type functions, and the value of μ is smaller, then deformed s type functions get over phase with sign function Seemingly, μ=0.01 is taken；

Then, by using the sigmoid function approximation sign functions of deformation, constraint equation (11), (14) and (20) It will be changed into the expression-form shown in formula (22), (23) and (24)：

By carrying out smoothing processing, then above-mentioned DES to the sign function in constraint equation (11), (14) and (20) Distribute rationally and be converted into continuous Nonlinear programming Model with moving model, carried out using the CONOPT solution musical instruments used in a Buddhist or Taoist mass in GAMS softwares Solve.

Compared with prior art, the present invention its advantage is：

1) propose that Optimized model can be to the discharge and recharge of the installation site of DES, rated power, specified electric quantity and day part State and power are carried out at the same time Optimal Decision-making；

2) this method considers supporting role of the voltage ＆ var control characteristic of DES to LVDN voltages, have also contemplated that at the same time The installation points limitation of DES in LVDN；

3) DES is distributed rationally in the LVDN obtained can improve higher level's load rate of grid with operating scheme, while can Reduce the active loss of LVDN, and make it that each node voltage does not get over the upper limit in photovoltaic output fluctuation range.

Brief description of the drawings

Fig. 1 is distributed rationally for the low-voltage network distributed energy storage provided in an embodiment of the present invention containing photovoltaic and operation method Flow chart；

Fig. 2 is the wiring diagram of certain actual LVDN；

Fig. 3 is taiwan area typical day load curve figure；

Fig. 4 it is expected power curve figure for taiwan area photovoltaic day；

Fig. 5 always injects active curve comparison figure for higher level's power grid before and after optimization；

Fig. 6 always injects the minimum corresponding energy storage charging and discharging curve figure of active fluctuation for higher level's power grid.

Embodiment

Present disclosure is described in further details with reference to the accompanying drawings and detailed description.

Embodiment：

The present embodiment proposes the method that the low-voltage network distributed energy storage containing photovoltaic is distributed rationally and run, its is specific Process is as follows：

First, according to the requirement for allowing node voltage offset, configured using DES and operation goes out fluctuation to eliminate photovoltaic Caused voltage out-of-limit, it is proposed that a kind of method for determining the total rated power and total specified electric quantity of DES needed for whole LVDN, first Determine the total rated power of DES, step is as follows：

1) fluctuation range contributed according to photovoltaic, accounts for the optimal load flow calculating that photovoltaic goes out fluctuation, can obtain The magnitude of voltage of the minimum node of voltage and corresponding photovoltaic is contributed at this time in LVDN.

2) the optimal load flow calculating that photovoltaic goes out fluctuation similarly, is accounted for, can obtain voltage highest node in LVDN Magnitude of voltage and corresponding photovoltaic is contributed at this time.

3) judge whether out-of-limit in above two photovoltaic output scene lower node minimum voltage and ceiling voltage.If two kinds of fields Occurs the voltage that node voltage is out-of-limit, then corresponding photovoltaic is contributed with the minimum node of voltage under calculating minimum voltage scene under scape Value just reaches the difference between corresponding photovoltaic output during 0.90p.u., while calculates corresponding photovoltaic under ceiling voltage scene The difference contributed when being just down to 1.07p.u. with the magnitude of voltage of voltage highest node between corresponding photovoltaic output, and take both In higher value as required DES total rated powers；It is out-of-limit that if node voltage occurs in only a kind of scene, with the scene The difference that the photovoltaic that corresponding photovoltaic is contributed when qualified critical value is in node voltage is contributed is as the total specified work(of required DES Rate.

Step 1) and 2) in, the optimal load flow computation model of use is respectively such as formula (1) and (2).

In step 3), photovoltaic when node voltage is in qualified critical value is contributed to be obtained by Load flow calculation, wherein, Photovoltaic is contributed as unknown quantity, if containing multiple photovoltaic nodes in LVDN, the active power output of all photovoltaic nodes it is expected Fluctuated on the basis of value according to same ratio, while using the voltage magnitude of all photovoltaic nodes as unknown quantity, that is, be equal to qualification Critical value, thus unknown quantity number is equal with equation number, power flow equation can solve.

Total specified electric quantity of DES needed for whole LVDN is determined again, and the definite needs of the total specified electric quantities of DES consider to contain photovoltaic The intraday continuous operation conditions of LVDN, the time interval using 1h as research, it is comprised the following steps that：

1) Load flow calculation of discontinuity surface, show that LVDN is deposited in one day 24h when carrying out one day 24 under minimum photovoltaic output All moment of lower limit are got in node voltage.

2) each moment that lower limit is got over to voltage carries out Load flow calculation, the voltage for each minimum node of moment voltage that must send as an envoy to The photovoltaic that value just reaches corresponding during 0.9p.u. is contributed, and calculates photovoltaic output and minimum that all voltages get over the lower limit moment The difference of photovoltaic output and summation.

3) Load flow calculation of discontinuity surface, show that LVDN is deposited in one day 24h when carrying out one day 24 under maximum photovoltaic output All moment of the upper limit are got in node voltage.

4) Load flow calculation, the voltage for each moment voltage highest node that must send as an envoy to are carried out to each moment of Over High-Limit Voltage Value is just down to photovoltaic corresponding during 1.07p.u. and contributes, and the photovoltaic for calculating all Over High-Limit Voltage moment is contributed and maximum The difference of photovoltaic output and summation.

5) higher value of result of calculation in above-mentioned steps (2) and (4) is taken as total specified electric quantity of required DES.

Secondly, structure DES is distributed rationally and moving model, and the model is solved to obtain the excellent of DES in LVDN Change configuration and operating scheme, step are as follows：

1) Optimized model is used as object function using higher level's load rate of grid.Rate of load condensate is total for higher level's power grid in one day 24h Active average value divided by maximum are injected, such as formula (3)：

In formula, P_grid,tRepresent total active power of period t higher level's power grid injection LVDN.Max { } represent to one day 24 Period higher level's power grid injection LVDN is always active to be maximized.

The max { } function contained in formula (3) is function that is discontinuous, can not leading, adds the difficulty of model solution.By Got over hour in the variance yields for always injecting active curve, curve fluctuation is also smaller, and is continuous function, therefore uses and minimize total injection Active variance replaces maximization rate of load condensate to be solved as target.Always inject the expression formula such as formula (4) of active variance：

2) Optimized model includes following constraints：

A) node power Constraints of Equilibrium：

B) voltage bound constrains：

V_min≤V_i,t≤V_max \*MERGEFORMAT(9)

In formula, V_minAnd V_maxThe lower and upper limit of node voltage are represented respectively.

C) system safety operation constrains:

In formula, S_TRepresent the rated capacity of distribution transformer.

D) the installation number constraint of energy storage:

Due to involving great expense for current energy storage, to reduce the cost of investment of energy storage, increase economic efficiency, DES in LVDN Installing number of nodes should not be excessive, tackles it and is defined, as follows：

According to formula (12), when candidate installs the energy storage rated power of nodeDuring more than 0, then the node needs to install storage Energy；When candidate installs the energy storage rated power of nodeDuring equal to 0, then the node is not required to installation energy storage.The Optimized model of this paper Middle all nodes using in addition to distribution transforming both high side node 22 all install node as the candidate of DES, are stored up by Optimization Solution The installation site of energy, avoids the subjectivity of artificial selection energy storage mount point.

E) energy storage total rated power and total specified Constraint:

F) energy storage charge-discharge electric power constrains:

G) the remaining capacity constraint of energy storage:

In formula,Represent the initial quantity of electricity of node i DES；η_cAnd η_dThe charge and discharge efficiency of DES is represented respectively；Δ t is represented The time interval of one period, is 1h.

H) the voltage power-less characteristic constraint of energy storage:

3) smoothing to sign function in constraint equation is handled.Constraint equation (11), (14) and (20) contains Sign function.Due to sign function sgn (x) at x=0 it is discontinuous, when above-mentioned Optimized model directly solves in GAMS softwares Difficulty will greatly increase, if sign function can be converted into continuous function, the solution difficulty of model will substantially reduce, therefore It is necessary that finding another continuous function carrys out close approximation sign function, which can continuously lead at x=0.In view of s The image shape of type function, that is, sigmoid functions is similar with sign function sgn (x), and rationally deformation is carried out to sigmoid functions just Programmable single-chip system sign function, as shown in formula (21)：

In formula, μ is the abrupt slope constant of s type functions, and the value of μ is smaller, then deformed s type functions get over phase with sign function Seemingly, μ=0.01 is taken herein.

Then, by using the sigmoid function approximation sign functions of deformation, constraint equation (11), (14) and (20) It will be changed into the expression-form shown in formula (22), (23) and (24).

By carrying out smoothing processing, then above-mentioned DES to the sign function in constraint equation (11), (14) and (20) Distribute rationally and be converted into continuous Nonlinear programming Model with moving model, using in GAMS softwares CONOPT solve musical instruments used in a Buddhist or Taoist mass into Row solves.

Therefore, a kind of low-voltage network distributed energy storage containing photovoltaic that the present embodiment is proposed is distributed rationally and operation side The flow chart of method is as indicated with 1.

In addition, in order to verify the present embodiment propose a kind of low-voltage network distributed energy storage containing photovoltaic distribute rationally with The validity of operation method, the present embodiment also carry out following l-G simulation test verification：

Choose some actual LVDN and carry out simulation analysis as example, the topological structure of the LVDN is as shown in Fig. 2, each negative The performance number of lotus node is as shown in table 1, according to the typical day load curve after normalization as shown in Figure 2, and chooses t=in figure The load power value of 13h is the value in table 1, and assumes that other period power factors are equal to the power factor of the period, you can Obtain the load power value of each node in one day 24h.The active power curve of expectation of photovoltaic node is as shown in Figure 3 in one day 24h. The efficiency for charge-discharge of DES is respectively 0.95 and 0.90, and maximum installation points are 3.Each load bus voltage bound is respectively 0.90p.u.、1.07p.u.。

The performance number of 1 each load bus of table

Under the desired value that load power and photovoltaic are contributed, Load flow calculation is carried out using perunit value, reference power is 100kVA, the reference voltage of distribution transformer high and low pressure side is respectively 10kV, 380V, if node 22 is balance nodes, trend knot Fruit shows that all node voltages are not out-of-limit in LVDN, its 5 voltage of interior joint is minimum, is 0.9139p.u.；21 voltage of node is most Height, is 1.0661p.u..

Consider photovoltaic go out fluctuation carry out Load flow calculation, it is assumed that day part power swing scope relative to desired value percentage Minimum than that for [0,130%], can obtain 5 voltage of egress, its perunit value is 0.8672, less than quality of voltage lower limit requirement 0.90, It is 0 that corresponding photovoltaic, which is contributed, at this time, and when the voltage of node 5 is just reached 0.90, the output of photovoltaic node 19 and 20 is respectively 13.686kW、9.964kW；21 voltage highest of node, its perunit value are 1.0664, and 1.07 are required not less than the quality of voltage upper limit, Corresponding photovoltaic is contributed as the 130% of desired value at this time.

Only there is the situation of more lower limit since photovoltaic goes out fluctuation time point voltage, therefore contributed with the corresponding photovoltaic of the scene The difference that photovoltaic when reaching 0.90p.u. with the voltage of the minimum node of voltage is contributed is always specified as DES needed for the LVDN Power, is 23.65kW.

24h Load flow calculations are carried out under minimum photovoltaic output, having at the time of node voltage gets over lower limit has t=10, 11 ..., 23h, to make the voltage of corresponding each minimum value node of moment voltage reach 0.90, at this time corresponding photovoltaic contribute with The difference that minimum photovoltaic is contributed is as shown in table 2：

The each voltage out-of-limit period magnitude of voltage of table 2 just reaches the corresponding photovoltaics of 0.9p.u. and contributes and minimum photovoltaic output Difference

Load flow calculation is carried out under maximum photovoltaic output, each node voltage does not get over the upper limit；Then institute in the LVDN can be obtained The total specified electric quantities of DES needed are 374.036kWh.

According to the DES total rated powers of above-mentioned gained and total specified electric quantity, it is minimum that active fluctuation is always injected with higher level's power grid Optimized for object function, the results are shown in Table 3, it can be seen that before higher level's power grid always injects active variance yields by optimizing 0.09957 drop to 0.01015, rate of load condensate rises to 0.906 by 0.791 before optimizing, and always injects active fluctuation and substantially subtracts It is small, since the lifting of higher level's load rate of grid reduces the peak-valley difference of each branch circuit load to a certain extent so that the LVDN Network loss also than small before optimization, 586.862kW is decreased to by the 631.331kW before optimizing.Fig. 4 is higher level's power grid before and after optimization Always inject active curve comparison figure, it can be seen that the curve after optimization is fluctuated than being obviously reduced before optimization.

Table 3 optimizes the contrast of front and rear result

The optimal charge-discharge electric power curve of DES is as shown in Figure 5.It can be seen that DES days charge-discharge electric power curves and the LVDN The tendency of typical day load curve is similar, i.e., DES charges when load is at a low ebb, and when load is in peak, DES discharges.Body The characteristics of having showed DES " low storage is occurred frequently ", thus the peak-valley difference of each branch circuit load is reduced in LVDN, is conducive to higher level's power grid and is born The reduction of raising and the network active loss of lotus rate.

As the above analysis, a kind of low-voltage network distributed energy storage containing photovoltaic that the present embodiment proposes is distributed rationally With the method for operation, this method is first according to allowing node voltage the requirement of offset come the total of DES needed for determining whole LVDN Rated power and total specified electric quantity, then construct and are up to target with higher level's load rate of grid, consider the voltage power-less control of DES The Optimized model of the installation points limitation of DES, optimum results show in supporting role and LVDN of the characteristic processed to LVDN voltages Itd is proposed Optimized model can be to the charging and discharging state and power of the installation site of DES, rated power, specified electric quantity and day part Optimal Decision-making is carried out at the same time, also the active loss of power grid can be made to obtain one while being optimized to higher level's load rate of grid Determine the reduction of degree.

Above-described embodiment is in the art the purpose is to be to allow simply to illustrate that the technical concepts and features of the present invention Those of ordinary skill can understand present disclosure and implement according to this, and it is not intended to limit the scope of the present invention.It is all It is the equivalent change or modification that the essence of content according to the present invention is made, should all covers within the scope of the present invention.

Claims

1. the low-voltage network distributed energy storage containing photovoltaic is distributed rationally and operation method, it is characterised in that the described method includes：

Structure DES is distributed rationally and moving model

<mrow> <mtable> <mtr> <mtd> <mrow> <mi>f</mi> <mo>=</mo> <mfrac> <mrow> <mfrac> <mn>1</mn> <mn>24</mn> </mfrac> <munderover> <mo>&Sigma;</mo> <mrow> <mi>t</mi> <mo>=</mo> <mn>1</mn> </mrow> <mn>24</mn> </munderover> <msub> <mi>P</mi> <mrow> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> </mrow> <mrow> <mi>m</mi> <mi>a</mi> <mi>x</mi> <mo>{</mo> <msub> <mi>P</mi> <mrow> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> <mo>,</mo> <mn>1</mn> </mrow> </msub> <mo>,</mo> <msub> <mi>P</mi> <mrow> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> <mo>,</mo> <mn>2</mn> </mrow> </msub> <mo>,</mo> <mo>...</mo> <msub> <mi>P</mi> <mrow> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mo>,</mo> <mo>...</mo> <mo>,</mo> <msub> <mi>P</mi> <mrow> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> <mo>,</mo> <mn>24</mn> </mrow> </msub> <mo>}</mo> </mrow> </mfrac> </mrow> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>3</mn> <mo>)</mo> </mrow> </mrow>

In formula, P_grid,tRepresent total active power of period t higher level's power grid injection LVDN, max { } was represented to one day 24 period Higher level's power grid injection LVDN is always active to be maximized；

Always injecting active variance using minimum replaces maximization rate of load condensate that the DES is distributed rationally and run as target Model is solved, this always injects the expression formula such as formula (4) of active variance：

<mrow> <mtable> <mtr> <mtd> <mrow> <mi>f</mi> <mo>=</mo> <mfrac> <mn>1</mn> <mn>24</mn> </mfrac> <munderover> <mo>&Sigma;</mo> <mrow> <mi>t</mi> <mo>=</mo> <mn>1</mn> </mrow> <mn>24</mn> </munderover> <msup> <mrow> <mo>(</mo> <msub> <mi>P</mi> <mrow> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mo>-</mo> <mfrac> <mn>1</mn> <mn>24</mn> </mfrac> <munderover> <mo>&Sigma;</mo> <mrow> <mi>t</mi> <mo>=</mo> <mn>1</mn> </mrow> <mn>24</mn> </munderover> <msub> <mi>P</mi> <mrow> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mo>)</mo> </mrow> <mn>2</mn> </msup> </mrow> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>4</mn> <mo>)</mo> </mrow> </mrow>

2. the low-voltage network distributed energy storage containing photovoltaic is distributed rationally and operation method as claimed in claim 1, its feature It is, the total rated power of the definite DES includes the following steps：

S11, the fluctuation range contributed according to photovoltaic, account for the optimal load flow calculating that photovoltaic goes out fluctuation, obtain in LVDN The magnitude of voltage of the minimum node of voltage and at this time corresponding photovoltaic output；

S12, account for photovoltaic and go out the optimal load flow of fluctuation calculating, and obtains in LVDN the magnitude of voltage of voltage highest node and this When corresponding photovoltaic contribute；

S13, judge whether get in two kinds of photovoltaic output scene lower node minimum voltages of above-mentioned steps S11, S12 and ceiling voltage Limit；

In step S11 and S12, the optimal load flow computation model of use is respectively such as formula (1) and (2)：

<mrow> <mtable> <mtr> <mtd> <mfenced open = "{" close = ""> <mtable> <mtr> <mtd> <mtable> <mtr> <mtd> <munder> <mi>min</mi> <msub> <mi>P</mi> <mrow> <mi>L</mi> <mo>,</mo> <mi>p</mi> <mi>v</mi> </mrow> </msub> </munder> </mtd> <mtd> <msub> <mi>V</mi> <mrow> <mi>L</mi> <mo>,</mo> <mi>min</mi> </mrow> </msub> </mtd> </mtr> </mtable> </mtd> </mtr> <mtr> <mtd> <mtable> <mtr> <mtd> <mrow> <mi>s</mi> <mo>.</mo> <mi>t</mi> <mo>.</mo> </mrow> </mtd> <mtd> <mrow> <msub> <mi>g</mi> <mi>L</mi> </msub> <mrow> <mo>(</mo> <msub> <mi>V</mi> <mi>L</mi> </msub> <mo>,</mo> <msub> <mi>&theta;</mi> <mi>L</mi> </msub> <mo>,</mo> <msub> <mi>P</mi> <mrow> <mi>L</mi> <mo>,</mo> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> </mrow> </msub> <mo>,</mo> <msub> <mi>P</mi> <mrow> <mi>L</mi> <mo>,</mo> <mi>p</mi> <mi>v</mi> </mrow> </msub> <mo>)</mo> </mrow> <mo>=</mo> <mn>0</mn> </mrow> </mtd> </mtr> </mtable> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>P</mi> <mrow> <mi>p</mi> <mi>v</mi> <mo>,</mo> <mi>m</mi> <mi>i</mi> <mi>n</mi> </mrow> </msub> <mo>&le;</mo> <msub> <mi>P</mi> <mrow> <mi>L</mi> <mo>,</mo> <mi>p</mi> <mi>v</mi> </mrow> </msub> <mo>&le;</mo> <msub> <mi>P</mi> <mrow> <mi>p</mi> <mi>v</mi> <mo>,</mo> <mi>m</mi> <mi>a</mi> <mi>x</mi> </mrow> </msub> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>P</mi> <mrow> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> <mo>,</mo> <mi>m</mi> <mi>i</mi> <mi>n</mi> </mrow> </msub> <mo>&le;</mo> <msub> <mi>P</mi> <mrow> <mi>L</mi> <mo>,</mo> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> </mrow> </msub> <mo>&le;</mo> <msub> <mi>P</mi> <mrow> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> <mo>,</mo> <mi>m</mi> <mi>a</mi> <mi>x</mi> </mrow> </msub> </mrow> </mtd> </mtr> </mtable> </mfenced> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>1</mn> <mo>)</mo> </mrow> </mrow>

<mrow> <mtable> <mtr> <mtd> <mfenced open = "{" close = ""> <mtable> <mtr> <mtd> <mtable> <mtr> <mtd> <munder> <mi>max</mi> <msub> <mi>P</mi> <mrow> <mi>H</mi> <mo>,</mo> <mi>p</mi> <mi>v</mi> </mrow> </msub> </munder> </mtd> <mtd> <msub> <mi>V</mi> <mrow> <mi>H</mi> <mo>,</mo> <mi>max</mi> </mrow> </msub> </mtd> </mtr> </mtable> </mtd> </mtr> <mtr> <mtd> <mtable> <mtr> <mtd> <mrow> <mi>s</mi> <mo>.</mo> <mi>t</mi> <mo>.</mo> </mrow> </mtd> <mtd> <mrow> <msub> <mi>g</mi> <mi>H</mi> </msub> <mrow> <mo>(</mo> <msub> <mi>V</mi> <mi>H</mi> </msub> <mo>,</mo> <msub> <mi>&theta;</mi> <mi>H</mi> </msub> <mo>,</mo> <msub> <mi>P</mi> <mrow> <mi>H</mi> <mo>,</mo> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> </mrow> </msub> <mo>,</mo> <msub> <mi>P</mi> <mrow> <mi>H</mi> <mo>,</mo> <mi>p</mi> <mi>v</mi> </mrow> </msub> <mo>)</mo> </mrow> <mo>=</mo> <mn>0</mn> </mrow> </mtd> </mtr> </mtable> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>P</mi> <mrow> <mi>p</mi> <mi>v</mi> <mo>,</mo> <mi>m</mi> <mi>i</mi> <mi>n</mi> </mrow> </msub> <mo>&le;</mo> <msub> <mi>P</mi> <mrow> <mi>H</mi> <mo>,</mo> <mi>p</mi> <mi>v</mi> </mrow> </msub> <mo>&le;</mo> <msub> <mi>P</mi> <mrow> <mi>p</mi> <mi>v</mi> <mo>,</mo> <mi>m</mi> <mi>a</mi> <mi>x</mi> </mrow> </msub> </mrow> </mtd> </mtr> <mtr> <mtd> <mrow> <msub> <mi>P</mi> <mrow> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> <mo>,</mo> <mi>m</mi> <mi>i</mi> <mi>n</mi> </mrow> </msub> <mo>&le;</mo> <msub> <mi>P</mi> <mrow> <mi>H</mi> <mo>,</mo> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> </mrow> </msub> <mo>&le;</mo> <msub> <mi>P</mi> <mrow> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> <mo>,</mo> <mi>m</mi> <mi>a</mi> <mi>x</mi> </mrow> </msub> </mrow> </mtd> </mtr> </mtable> </mfenced> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>2</mn> <mo>)</mo> </mrow> </mrow>

In formula, V_L,minAnd V_H,maxThe electricity of the minimum node of voltage and voltage highest node under corresponding photovoltaic output scene is represented respectively Pressure value, the minimum node of voltage and voltage highest node are obtained by the Load flow calculation under photovoltaic output desired value scene；Equality constraint g_L() and g_H() is illustrated respectively under the minimum and highest scene of node voltage, the power-balance of each node in system Equation；V_LAnd V_HRepresent the voltage of each node under two kinds of scenes；θ_LAnd θ_HRepresent the voltage phase angle of each node under two kinds of scenes； P_L,gridAnd P_H,gridRepresent total active power of higher level's power grid injection LVDN under two kinds of scenes；P_grid,maxAnd P_grid,minRespectively Represent the upper and lower limit of higher level's power grid injection total active power of LVDN；P_L,pvAnd P_H,pvRepresent that corresponding photovoltaic goes out under two kinds of scenes Power；P_pv,maxAnd P_pv,minThe upper and lower limit of photovoltaic active power output is represented respectively；Distributed photovoltaic use power factor permanent for 1 control The idle output of mode processed, i.e. photo-voltaic power supply is zero；

In step S13, photovoltaic when node voltage is in qualified critical value is contributed to be obtained by Load flow calculation, wherein, will Photovoltaic contributes and is used as unknown quantity, if containing multiple photovoltaic nodes in LVDN, the active power output of all photovoltaic nodes is in desired value On the basis of fluctuated according to same ratio, while using the voltage magnitude of all photovoltaic nodes as unknown quantity, i.e., face equal to qualification Dividing value, thus unknown quantity number is equal with equation number, power flow equation can solve.

3. the low-voltage network distributed energy storage containing photovoltaic is distributed rationally and operation method as claimed in claim 1 or 2, it is special Sign is that the total specified electric quantity for determining DES needed for whole LVDN includes the following steps：

S101, when carrying out one day 24 under minimum photovoltaic output discontinuity surface Load flow calculation, show in one day 24h that LVDN exists Node voltage gets over all moment of lower limit；

S102, progress of each moment Load flow calculation that lower limit is got over to voltage, the voltage for each minimum node of moment voltage that must send as an envoy to Value just reaches corresponding photovoltaic when calculating standard value and contributes, and calculate all voltages get over the lower limit moment photovoltaic contribute with most The difference of small photovoltaic output and summation；

S103, when carrying out one day 24 under maximum photovoltaic output discontinuity surface Load flow calculation, show in one day 24h that LVDN exists Node voltage gets over all moment of the upper limit；

S104, each moment to Over High-Limit Voltage carry out Load flow calculation, the voltage for each moment voltage highest node that must send as an envoy to Value is just down to corresponding photovoltaic when calculating standard value and contributes, and the photovoltaic for calculating all Over High-Limit Voltage moment contribute with most The difference of big photovoltaic output and summation；

4. the low-voltage network distributed energy storage containing photovoltaic is distributed rationally and operation method as claimed in claim 1, its feature It is, the DES is distributed rationally includes following constraints with moving model：Node power Constraints of Equilibrium, voltage bound are about Beam, system safety operation constraint, the installation number constraint of energy storage, energy storage total rated power and total specified Constraint, energy storage are filled Discharge power constraint, the remaining capacity constraint of energy storage, the voltage power-less characteristic constraint of energy storage.

5. the low-voltage network distributed energy storage containing photovoltaic is distributed rationally and operation method as claimed in claim 4, its feature It is, the node power Constraints of Equilibrium is：

<mrow> <mtable> <mtr> <mtd> <mrow> <msubsup> <mi>P</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> <mrow> <mi>P</mi> <mi>V</mi> </mrow> </msubsup> <mo>+</mo> <msubsup> <mi>P</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> <mrow> <mi>D</mi> <mi>C</mi> <mi>H</mi> </mrow> </msubsup> <mo>+</mo> <msubsup> <mi>P</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> <mrow> <mi>C</mi> <mi>H</mi> </mrow> </msubsup> <mo>-</mo> <msubsup> <mi>P</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> <mrow> <mi>L</mi> <mi>D</mi> </mrow> </msubsup> <mo>-</mo> <msub> <mi>V</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <munderover> <mo>&Sigma;</mo> <mrow> <mi>j</mi> <mo>=</mo> <mn>1</mn> </mrow> <mi>N</mi> </munderover> <msub> <mi>V</mi> <mrow> <mi>j</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mrow> <mo>(</mo> <msub> <mi>G</mi> <mrow> <mi>i</mi> <mi>j</mi> </mrow> </msub> <msub> <mi>cos&theta;</mi> <mrow> <mi>i</mi> <mi>j</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mo>+</mo> <msub> <mi>B</mi> <mrow> <mi>i</mi> <mi>j</mi> </mrow> </msub> <msub> <mi>sin&theta;</mi> <mrow> <mi>i</mi> <mi>j</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mo>)</mo> </mrow> <mo>=</mo> <mn>0</mn> </mrow> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>5</mn> <mo>)</mo> </mrow> </mrow>

<mrow> <mtable> <mtr> <mtd> <mrow> <msubsup> <mi>Q</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> <mrow> <mi>P</mi> <mi>V</mi> </mrow> </msubsup> <mo>+</mo> <msubsup> <mi>Q</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msubsup> <mo>-</mo> <msubsup> <mi>Q</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> <mrow> <mi>L</mi> <mi>D</mi> </mrow> </msubsup> <mo>-</mo> <msub> <mi>V</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <munderover> <mo>&Sigma;</mo> <mrow> <mi>j</mi> <mo>=</mo> <mn>1</mn> </mrow> <mi>N</mi> </munderover> <msub> <mi>V</mi> <mrow> <mi>j</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mrow> <mo>(</mo> <msub> <mi>G</mi> <mrow> <mi>i</mi> <mi>j</mi> </mrow> </msub> <msub> <mi>sin&theta;</mi> <mrow> <mi>i</mi> <mi>j</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mo>-</mo> <msub> <mi>B</mi> <mrow> <mi>i</mi> <mi>j</mi> </mrow> </msub> <msub> <mi>cos&theta;</mi> <mrow> <mi>i</mi> <mi>j</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mo>)</mo> </mrow> <mo>=</mo> <mn>0</mn> </mrow> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>6</mn> <mo>)</mo> </mrow> </mrow>

<mrow> <mtable> <mtr> <mtd> <mrow> <msub> <mi>P</mi> <mrow> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mo>-</mo> <msub> <mi>V</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <munderover> <mo>&Sigma;</mo> <mrow> <mi>j</mi> <mo>=</mo> <mn>1</mn> </mrow> <mi>N</mi> </munderover> <msub> <mi>V</mi> <mrow> <mi>j</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mrow> <mo>(</mo> <msub> <mi>G</mi> <mrow> <mi>i</mi> <mi>j</mi> </mrow> </msub> <msub> <mi>cos&theta;</mi> <mrow> <mi>i</mi> <mi>j</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mo>+</mo> <msub> <mi>B</mi> <mrow> <mi>i</mi> <mi>j</mi> </mrow> </msub> <msub> <mi>sin&theta;</mi> <mrow> <mi>i</mi> <mi>j</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mo>)</mo> </mrow> <mo>=</mo> <mn>0</mn> </mrow> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>7</mn> <mo>)</mo> </mrow> </mrow>

<mrow> <mtable> <mtr> <mtd> <mrow> <msub> <mi>Q</mi> <mrow> <mi>g</mi> <mi>r</mi> <mi>i</mi> <mi>d</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mo>-</mo> <msub> <mi>V</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <munderover> <mo>&Sigma;</mo> <mrow> <mi>j</mi> <mo>=</mo> <mn>1</mn> </mrow> <mi>N</mi> </munderover> <msub> <mi>V</mi> <mrow> <mi>j</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mrow> <mo>(</mo> <msub> <mi>G</mi> <mrow> <mi>i</mi> <mi>j</mi> </mrow> </msub> <msub> <mi>sin&theta;</mi> <mrow> <mi>i</mi> <mi>j</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mo>-</mo> <msub> <mi>B</mi> <mrow> <mi>i</mi> <mi>j</mi> </mrow> </msub> <msub> <mi>cos&theta;</mi> <mrow> <mi>i</mi> <mi>j</mi> <mo>,</mo> <mi>t</mi> </mrow> </msub> <mo>)</mo> </mrow> <mo>=</mo> <mn>0</mn> </mrow> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>8</mn> <mo>)</mo> </mrow> </mrow>

In formula,Represent the active power output of period t node i photovoltaic；WithRepresent respectively the filling of period t node i DES, Discharge power, it is assumed that the active power output of DES is just during electric discharge, and the active power output of DES is negative during charging；By energy storage charge and discharge below The constraint of electrical power bound understands, when the DES installation nodes of some candidate in optimum results are fitted without DES, then the nodeWithAll will be 0；Represent the active power of period t node i load；And V_jtRespectively represent the period t node i and The voltage magnitude of node j；θ_ij,tRepresent the phase difference of voltage between period t node i, j；G_ijAnd B_ijNode admittance square is represented respectively The real and imaginary parts of i-th row jth column element in battle array；Represent the reactive power of period t node i load；Q_grid,tRepresent the period T higher level's power grid injects total reactive power of LVDN,Represent the idle output of photovoltaic of period t node i；Represent period t section The reactive power of the energy storage injection power distribution network of point i；N is the node total number of LVDN；Hop count when T is, using 1h as a period, one day Totally 24 periods.

6. the low-voltage network distributed energy storage containing photovoltaic is distributed rationally and operation method as described in claim 4 or 5, it is special Sign is that the voltage bound is constrained to：

V_min≤V_i,t≤V_max\*MERGEFORMAT(9)

The system safety operation is constrained to：

In formula, S_TRepresent the rated capacity of distribution transformer.

7. the low-voltage network distributed energy storage containing photovoltaic is distributed rationally and operation method as claimed in claim 6, its feature It is, the installation number of the energy storage is constrained to:

<mrow> <mtable> <mtr> <mtd> <mrow> <munder> <mo>&Sigma;</mo> <mrow> <mi>i</mi> <mo>&Element;</mo> <msub> <mi>S</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msub> </mrow> </munder> <mi>sgn</mi> <mrow> <mo>(</mo> <msubsup> <mi>P</mi> <mi>i</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msubsup> <mo>)</mo> </mrow> <mo>&le;</mo> <msub> <mi>N</mi> <mrow> <mi>m</mi> <mi>a</mi> <mi>x</mi> </mrow> </msub> </mrow> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>11</mn> <mo>)</mo> </mrow> </mrow>

In formula, S_ESRepresent the DES installation node sets of candidate, N_maxRepresent the maximum quantity for allowing the DES of access in LVDN；This In application in addition to distribution transformer high-pressure side node, DES of other nodes as candidate in LVDN installs node；When will match somebody with somebody When piezoelectric transformer both high side node 22 volume is N nodes, then the DES of candidate installs node set S_ES={ 1,2 ..., N-1 }；Symbol Number functionMathematic(al) representation it is as follows：

According to formula (12), when candidate installs the energy storage rated power of nodeDuring more than 0, then the node needs to install energy storage；When Candidate installs the energy storage rated power of nodeDuring equal to 0, then the node is not required to installation energy storage.

8. the low-voltage network distributed energy storage containing photovoltaic is distributed rationally and operation method as claimed in claim 7, its feature It is, the energy storage total rated power and total specified Constraint are:

Needed for the DES rated power of DES installation nodes and the summation of specified electric quantity of all candidates should be respectively equal in power distribution network DES total rated powers and total specified electric quantity, it is as follows：

<mrow> <mtable> <mtr> <mtd> <mrow> <munder> <mo>&Sigma;</mo> <mrow> <mi>i</mi> <mo>&Element;</mo> <msub> <mi>S</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msub> </mrow> </munder> <msubsup> <mi>P</mi> <mi>i</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msubsup> <mo>=</mo> <msup> <mi>P</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msup> </mrow> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>13</mn> <mo>)</mo> </mrow> </mrow>

<mrow> <mtable> <mtr> <mtd> <mrow> <munder> <mo>&Sigma;</mo> <mrow> <mi>i</mi> <mo>&Element;</mo> <msub> <mi>S</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msub> </mrow> </munder> <mi>sgn</mi> <mrow> <mo>(</mo> <msubsup> <mi>P</mi> <mi>i</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msubsup> <mo>)</mo> </mrow> <msubsup> <mi>E</mi> <mi>i</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msubsup> <mo>=</mo> <msup> <mi>E</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msup> </mrow> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>14</mn> <mo>)</mo> </mrow> </mrow>

In formula,WithThe rated power and specified electric quantity of node i DES, P are represented respectively^ESAnd E^ESInstitute in LVDN is represented respectively The DES total rated powers needed and total specified electric quantity；In order to avoid there is some node in result of calculationAnd's Situation, uses sign function in formula (14)It is multiplied byAs long as so that some nodeRepresent the node Installation DES is not required to, then in total specified electric quantity E^ESComposition in the node DES specified electric quantities also be 0；

The energy storage charge-discharge electric power is constrained to:

Any time period t of energy storage device in operation, can be only in charge or discharge state, and the watt level of discharge and recharge is not Its rated value should be exceeded, it is as follows：

<mrow> <mtable> <mtr> <mtd> <mrow> <msubsup> <mi>P</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> <mrow> <mi>C</mi> <mi>H</mi> </mrow> </msubsup> <mo>&times;</mo> <msubsup> <mi>P</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> <mrow> <mi>D</mi> <mi>C</mi> <mi>H</mi> </mrow> </msubsup> <mo>=</mo> <mn>0</mn> </mrow> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>17</mn> <mo>)</mo> </mrow> </mrow>

From formula (15) and (16), installation node is not chosen as when the DES of some candidate in optimum results installs node, i.e., The candidate installs the energy storage rated power of nodeDuring equal to 0, the charge and discharge power of the DES of the nodeWithAll will For 0.

9. the low-voltage network distributed energy storage containing photovoltaic is distributed rationally and operation method as claimed in claim 8, its feature It is, the remaining capacity of the energy storage is constrained to:

It is assumed that the initial residual electricity of energy-storage units is the 50% of specified electric quantity, during for any one during storage energy operation T is carved, its remaining capacity is as follows no more than specified electric quantity：

<mrow> <mtable> <mtr> <mtd> <mrow> <mn>0</mn> <mo>&le;</mo> <msubsup> <mi>E</mi> <mi>i</mi> <mrow> <mi>I</mi> <mi>N</mi> <mi>I</mi> </mrow> </msubsup> <mo>-</mo> <munderover> <mo>&Sigma;</mo> <mrow> <mi>t</mi> <mo>=</mo> <mn>1</mn> </mrow> <msup> <mi>t</mi> <mo>&prime;</mo> </msup> </munderover> <mrow> <mo>(</mo> <msubsup> <mi>P</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> <mrow> <mi>C</mi> <mi>H</mi> </mrow> </msubsup> <msub> <mi>&eta;</mi> <mi>c</mi> </msub> <mo>+</mo> <msubsup> <mi>P</mi> <mrow> <mi>i</mi> <mo>,</mo> <mi>t</mi> </mrow> <mrow> <mi>D</mi> <mi>C</mi> <mi>H</mi> </mrow> </msubsup> <mo>/</mo> <msub> <mi>&eta;</mi> <mi>d</mi> </msub> <mo>)</mo> </mrow> <mi>&Delta;</mi> <mi>t</mi> <mo>&le;</mo> <msubsup> <mi>E</mi> <mi>i</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msubsup> <mo>,</mo> <msup> <mi>t</mi> <mo>&prime;</mo> </msup> <mo>=</mo> <mn>1</mn> <mo>,</mo> <mn>2</mn> <mo>,</mo> <mo>...</mo> <mo>,</mo> <mn>24</mn> </mrow> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>19</mn> <mo>)</mo> </mrow> </mrow>

In formula,Represent the initial quantity of electricity of node i DES；η_cAnd η_dThe charge and discharge efficiency of DES is represented respectively；Δ t represents one The time interval of period, is 1h；

The voltage power-less characteristic constraint of the energy storage:

In formula, n_QRepresent the sagging coefficient of voltage, be the constant between 0 to 1；V₀Represent the voltage of energy storage REACTIVE POWER/VOLTAGE droop characteristic Initial value, its perunit value are taken as 1；Sign function is multiplied by the right of equationExpression is only chosen as DES peaces in optimum results Fill node just can inject reactive power there are energy storage device to power distribution network

10. the low-voltage network distributed energy storage containing photovoltaic is distributed rationally and operation method as claimed in claim 9, its feature It is, the smoothing to sign function in constraint equation is handled：

Constraint equation (11), (14) and (20) contains sign function, due to sign function sgn (x) at x=0 it is discontinuous, Difficulty will greatly increase when above-mentioned Optimized model solves directly in GAMS softwares, if sign function can be converted into continuous letter Number, the solution difficulty of model will substantially reduce, it is therefore necessary to find another continuous function and carry out close approximation symbol letter Number, the function can continuously be led at x=0, in view of the image shape of s type functions, that is, sigmoid functions and sign function sgn (x) similar, rationally deformation is carried out to sigmoid functions can approach sign function, as shown in formula (21)：

In formula, μ is the abrupt slope constant of s type functions, and the value of μ is smaller, then deformed s type functions are more similar with sign function, Take μ=0.01；

Then, will become by using the sigmoid function approximation sign functions of deformation, constraint equation (11), (14) and (20) For the expression-form shown in formula (22), (23) and (24)：

<mrow> <mtable> <mtr> <mtd> <mrow> <munder> <mo>&Sigma;</mo> <mrow> <mi>i</mi> <mo>&Element;</mo> <msub> <mi>S</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msub> </mrow> </munder> <mrow> <mo>(</mo> <mfrac> <mn>2</mn> <mrow> <mn>1</mn> <mo>+</mo> <msup> <mi>e</mi> <mrow> <mo>-</mo> <mfrac> <msubsup> <mi>P</mi> <mi>i</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msubsup> <mi>&mu;</mi> </mfrac> </mrow> </msup> </mrow> </mfrac> <mo>-</mo> <mn>1</mn> <mo>)</mo> </mrow> <mo>&le;</mo> <msub> <mi>N</mi> <mrow> <mi>m</mi> <mi>a</mi> <mi>x</mi> </mrow> </msub> </mrow> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>22</mn> <mo>)</mo> </mrow> </mrow>

<mrow> <mtable> <mtr> <mtd> <mrow> <munder> <mo>&Sigma;</mo> <mrow> <mi>i</mi> <mo>&Element;</mo> <msub> <mi>S</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msub> </mrow> </munder> <mrow> <mo>(</mo> <mfrac> <mn>2</mn> <mrow> <mn>1</mn> <mo>+</mo> <msup> <mi>e</mi> <mrow> <mo>-</mo> <mfrac> <msubsup> <mi>P</mi> <mi>i</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msubsup> <mi>&mu;</mi> </mfrac> </mrow> </msup> </mrow> </mfrac> <mo>-</mo> <mn>1</mn> <mo>)</mo> </mrow> <msubsup> <mi>E</mi> <mi>i</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msubsup> <mo>=</mo> <msup> <mi>E</mi> <mrow> <mi>E</mi> <mi>S</mi> </mrow> </msup> </mrow> </mtd> <mtd> <mrow> <mo>\</mo> <mo>*</mo> <mi>M</mi> <mi>E</mi> <mi>R</mi> <mi>G</mi> <mi>E</mi> <mi>F</mi> <mi>O</mi> <mi>R</mi> <mi>M</mi> <mi>A</mi> <mi>T</mi> </mrow> </mtd> </mtr> </mtable> <mo>-</mo> <mo>-</mo> <mo>-</mo> <mrow> <mo>(</mo> <mn>23</mn> <mo>)</mo> </mrow> </mrow>

By carrying out smoothing processing to the sign function in constraint equation (11), (14) and (20), then above-mentioned DES optimizations Configuration is converted into continuous Nonlinear programming Model with moving model, is asked using the CONOPT solution musical instruments used in a Buddhist or Taoist mass in GAMS softwares Solution.