CN103001331A - Economic optimized dispatching method for energy storage power stations - Google Patents

Abstract

The invention relates to an economic optimized dispatching method for energy storage power stations. A system utilized in the economic optimized dispatching method comprises independent adjustable battery packs, a transformer, a transformer bus, and an energy storage monitoring system power dispatching center, wherein the independent adjustable battery packs are connected on the bus on the low-voltage side of the transformer, and the transformer and the energy storage monitoring system power dispatching center are sequentially communicated with a power grid dispatching system. The economic optimized dispatching method includes the steps of initializing data of a energy storage power station; confirming the number of the independent adjustable battery packs; reading operation parameters of the independent adjustable battery packs and uploading the same to the energy storage monitoring system power dispatching center; confirming the optimum economic optimized dispatching scheme to obtain the optimum economic optimized dispatching model; and outputting a power dispatching command of the battery packs of the energy storage power station. Concrete structure of the energy storage power station and technical characteristics of energy storage packs are fully taken into consideration, the lowest total cost is taken as the optimizing object, power demand of battery operation and dispatching is taken as a limiting condition, and the economic optimized dispatching method is simultaneously applicable to energy type energy storage power stations and power type energy storage power stations.

Description

A kind of economic optimization dispatching method of energy-accumulating power station

Technical field

The present invention relates to electric energy storing system operation and Optimum Scheduling Technology field, be specifically related to a kind of economic optimization dispatching method of energy-accumulating power station.

Background technology

Extensive energy-accumulating power station is made of a plurality of, polymorphic type energy-storage system, and number of batteries is many, consists of complexity, and the scheduling strategy of optimization is one of important evidence of guaranteeing whole power station economy, safety, reliability service.After energy-accumulating power station receives the grid power dispatch command, calculate by rational distribution principle, then the performance number that calculates finally is issued to each bar energy storage branch road, to satisfy the target of electrical network total activation power requirement and energy-storage system optimization operation.At present, domestic MW level energy-accumulating power station is in the demonstrating running stage, and the Optimized Operation strategy of energy-accumulating power station still is in theoretical research stage, temporary transient ripe solution of not generally acknowledging.

Summary of the invention

For the deficiencies in the prior art, the invention provides the economic optimization dispatching method of energy-accumulating power station, the method has taken into full account the concrete formation of energy-accumulating power station and the technical characteristic of energy-storage battery, take the lowest cost as optimization aim, take battery operation and the scheduling power demand as constraints, the method is applicable to energy type energy-accumulating power station and power-type energy-accumulating power station simultaneously.

The objective of the invention is to adopt following technical proposals to realize:

A kind of economic optimization dispatching method of energy-accumulating power station, the system that described method is used comprises independent adjustable battery group, transformer, transformer bus and energy storage monitor system power dispatching center; On the bus of described independent adjustable battery group access step down side; Described transformer and described energy storage monitor system power dispatching center communicate; Described energy storage monitor system power dispatching center and power network dispatching system communicate;

Its improvements are that described method comprises the steps:

(1) initialization energy-accumulating power station data;

(2) determine independently can dispatch the group number of battery pack;

(3) reading in described independence can dispatch the operational factor of battery pack and be uploaded to energy storage monitor system power dispatching center;

(4) determine Optimum Economic Optimized Operation scheme, draw the Optimum Economic Optimal Operation Model;

(5) the power dispatching instruction of output energy-accumulating power station battery pack.

Wherein, in the described step (1), described energy-accumulating power station comprises independently can dispatch battery pack; Described independence can be dispatched battery pack and be drawn together the energy storage branch road; Route energy accumulation current converter PCS, battery management system BMS and battery pile BP are propped up in described energy storage; Described energy-accumulating power station data refer to energy storage type and the parameter of energy accumulation current converter PCS, battery management system BMS and battery pile BP.

Wherein, in the described step (2), described independent adjustable battery group refers to the energy-storage battery group that battery operated state is identical in management and running, parameter synchronization changes; Determine that each independent adjustable battery group is as a control variables independently, with A _iExpression, i=1 wherein ..., N.

Wherein, in the described step (3), the operational factor that described independence can be dispatched battery pack comprises charge efficiency η _c, discharging efficiency η _d, battery minimum allow to discharge and recharge power

The maximum of battery allows to discharge and recharge power

The minimum of charged value SOC, battery allows carrying capacity The maximum of battery allows carrying capacity

With previous dispatching cycle of battery pack operating state u _i(t-1).

Wherein, the independent operational factor that can dispatch battery pack is uploaded to energy storage monitor system power dispatching center, the construction cost C that the independent group that can dispatch battery pack is counted N, battery pack input is read from database in energy storage monitor system power dispatching center simultaneously _Fl, the reactive power discharge coefficient β of permission _iWith battery pack discharge and recharge number of times r _i

Wherein, in the described step (4), determine that Optimum Economic Optimized Operation scheme comprises target function and the constraints of determining energy-accumulating power station.

Wherein, the target function of economic optimization scheduling scheme is minimum as optimization aim take total cost C, and control variables is taken as the active-power P of battery pack _iWith reactive power Q i, wherein: i=1 ..., N; Described total cost C comprises fixed cost C _fWith variable cost C _rAt energy-accumulating power station, fixed cost refers to install construction cost; Variable cost comprises operation expense C _mWith cost depletions C _l

Wherein, described operation expense C _mRepresent with following formula:

$C_m=\underset{i=1}{\overset{N}{\mathrm{\Σ}}}[({\∫}_0^T{k}_{\mathrm{ri}}\·\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\·\mathrm{dt})\·{(1+\mathrm{\α})}^{r_i/R_i}]$

$=T\·\underset{i=1}{\overset{N}{\mathrm{\Σ}}}\left[k_{\mathrm{ri}}\·\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\·{(1+\mathrm{\α})}^{r_i/R_i}\right]$ ①；

In the formula: T is dispatching cycle; k _RiBe that i organizes independent adjustable battery group operation maintenance coefficient, unit is unit/kWh; P _ItAnd Q _ItMeritorious and the reactive power for the scheduling of independent adjustable battery group; r _iAnd R _iBe respectively i and organize the global cycle number of times that independent adjustable battery group has discharged and recharged number of times and permission; α is aging coefficient, gets α=1.

Wherein, described cost depletions C _lRepresent with following expression formula group:

In the formula: k _lBe battery pack electric energy loss coefficient, unit is unit/kWh;

As independent adjustable battery group A _iDuring charging, T electric weight recruitment is in its dispatching cycle:

$\mathrm{\&Delta;}{E}_i={\&Integral;}_0^T{\mathrm{\&eta;}}_{\mathrm{ci}}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\mathrm{dt}={\mathrm{\&eta;}}_{\mathrm{ci}}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;\mathrm{<figure-callout\; id="3"\; label="T"\; filenames="HDA00002391906100022.png"\; state="\{\{state\}\}">T</figure-callout>}$ ③；

As independent adjustable battery group A _iDuring discharge, the interior electric weight recruitment of its dispatching cycle of T is:

$\mathrm{\&Delta;}{E}_{\text{i}}={\&Integral;}_0^T(\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}/{\mathrm{\&eta;}}_{\mathrm{di}})\mathrm{dt}=\frac{\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;T}{{\mathrm{\&eta;}}_{\mathrm{di}}}$ ④；

In the formula: η _cBe charge efficiency; η _dBe discharging efficiency.

Wherein, in energy-accumulating power station, judge that whether battery pack is called the flag bit that once independently discharges and recharges behavior is ρ _i, represent with following formula:

${\mathrm{\&rho;}}_i=\left\{\begin{array}{cc}0& u_i(t-1)\&CenterDot;u_i\left(t\right)=1\\ 1& \mathrm{else}\end{array}\right.$ ⑤；

In the formula: u _i(t) be current dispatching cycle T battery pack operating state; u _i(t-1) be previous dispatching cycle of battery pack operating state;

Described fixed cost C _fRepresent with following formula:

$C_f=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&rho;}}_i\&CenterDot;C_{\mathrm{fi}}}{R_i}$ ⑥；

In the formula: C _FiConstruction cost for arbitrary independent adjustable battery group; R _iBe that i organizes the global cycle number of times that independent adjustable battery group discharges and recharges permission.

Wherein, the target function of economic optimization scheduling scheme represents with following formula:

min C＝C _m+C _l+C _f ⑦。

Wherein, the constraints of economic optimization scheduling scheme comprises power-balance constraint, battery charging and discharging power constraint and carrying capacity constraint.

Wherein, described power-balance constraint represents with following formula:

$\left\{\begin{array}{c}{P}_{\mathrm{total}}=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{P}_i\\ Q_{\mathrm{total}}=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{Q}_i\end{array}\right.$ ⑧；

In the formula: P _TotalAnd Q _TotalBe respectively total activation active power demand and reactive power demand, unit is kW, and batteries charging is for just.

Wherein, the bound scope of described battery charging and discharging power is as follows:

During charging, u _i=1, P _iFor just,

9.;

During discharge, u _i=-1, P _iFor negative,

10.;

In the formula,

With

Be respectively i and organize minimum and the maximum charge active power of independent adjustable battery, unit is kW,

With

Be respectively i and organize minimum and the maximum discharge active power of independent adjustable battery, unit is kW;

The power that discharges and recharges of energy-accumulating power station satisfies following formula:

In the formula:

With

The minimum and the maximum that are respectively the i Battery pack always discharge and recharge power;

In the battery set charge/discharge process, reactive power satisfies following formula:

In the formula: β _iFor allowing to discharge idle coefficient, β _i≤ 1;-Q _iThe reactive power of sending for battery pack.

Wherein, described carrying capacity constraint represents with following formula:

In the formula:

With

Be respectively minimum and maximum carrying capacity that the i Battery pack allows.

Wherein, described Optimum Economic Optimal Operation Model represents with following expression formula group:

$\begin{array}{cc}\min & C=C_m\end{array}+C_l+C_f$

$=T\&CenterDot;\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}\left[k_{\mathrm{ri}}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;{(1+\mathrm{\&alpha;})}^{r_i/R_i}\right]$

$+k_{l}T\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}[(1-\mathrm{\&eta;})\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}]+\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&rho;}}_i\&CenterDot;C_{\mathrm{fi}}}{R_i}$

Wherein, $P_{\mathrm{total}}=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{P}_i$

$Q_{\mathrm{total}}=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{Q}_i$

$S_i^{\min }\&le;\sqrt{P_i^2+Q_i^2}\&le;S_i^{\max }$

${\mathrm{\&beta;}}_i\&CenterDot;S_i^{\min }\&le;-Q_i\&le;{\mathrm{\&beta;}}_i\&CenterDot;S_i^{\max }$

${\mathrm{SOC}}_i^{\min }\&le;{\mathrm{SOC}}_i\&le;{\mathrm{SOC}}_i^{\max }$

$\mathrm{\&Delta;}{E}_i=\mathrm{\&eta;}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;T$

${\mathrm{\&rho;}}_i=\left\{\begin{array}{cc}0& u_i(t-1)\&CenterDot;u_i\left(t\right)=1\\ 1& \mathrm{else}\end{array}\right.$

Wherein, when the energy storage branch road of energy-accumulating power station breaks down in the described method, the Optimum Economic Optimal Operation Model is revised in the following manner:

1) if i organizes independent adjustable battery group integral body to break down, then out of service, after keeping in repair, come into operation again; Remove by force the control variables P that i organizes independent adjustable battery group _iAnd Q _i, the control variables dimension subtracts 1;

2) certain energy storage branch road breaks down in the independent adjustable battery group if i organizes, and out of service the waiting of this fault energy storage branch road keeped in repair, and the remaining power group continues operation in this independent adjustable battery group, and all parameters that i is organized independent adjustable battery group are done to fall to hold and processed; After carrying out the parameter correction, Optimal Operation Model is constant.

Compared with the prior art, the beneficial effect that reaches of the present invention is:

1, energy storage monitor system is that whole energy-storage system is safe, reliable, the important leverage of economical operation as important component part and the senior control axis of energy-storage system.Energy storage monitor system not only receives the dispatch command of higher level's electrical network, also battery pile, energy accumulation current converter, on off state and the power distribution circuit of internal system is carried out monitoring and controlling, guarantees that energy-storage system is in optimum operating state.

2, the Optimization Scheduling of energy-accumulating power station is the core technology of energy storage monitor system, this patent has proposed a kind of take economic optimization as target first, considered the Optimization scheduling algorithm take the energy storage ontological property as constraints, be applicable to simultaneously power-type and energy type energy-accumulating power station, demonstrate fully the senior control function of energy storage monitor system, for promoting that energy-accumulating power station provides theoretical reference in economical operation and the application of intelligent grid and renewable energy source domain.

Description of drawings

Fig. 1 is the flow chart of the economic optimization dispatching method of energy-accumulating power station provided by the invention;

Fig. 2 is the energy-accumulating power station structural representation;

Fig. 3 independently can dispatch battery set charge/discharge power in each dispatching cycle;

Fig. 4 is independent adjustable battery group carrying capacity SOC variation diagram in each dispatching cycle.

Embodiment

Below in conjunction with accompanying drawing the specific embodiment of the present invention is described in further detail.

At first the relevant parameter in the energy-accumulating power station is defined and simplifies:

(1) independent adjustable battery group is an energy-storage battery group that battery operated state is identical, parameter synchronization changes in management and running.It is as a control variables independently, with Ai (i=1 ..., N) expression.May have many energy storage branch roads in the independent adjustable battery group, the energy storage type in the energy storage branch road is all identical with parameter.Energy storage is propped up an energy accumulation current converter of route (PCS), battery management system (BMS) and a battery pile (BP) and is formed.

(2) parameter in the independent adjustable battery group is identical, comprising: battery pack drops into construction cost, charge power Pc, charge efficiency η c, discharge power Pd, discharging efficiency η _d, battery set charge/discharge global cycle number of times R, carrying capacity SOC etc.

(3) in a dispatching cycle T, the total activation demand power is given, and the running status of battery does not change, and discharges and recharges power invariability.

(4) the battery pack operating state has 3 kinds, distinguishes with u.During charged state, u=1, charge power are Pc; During discharge condition, u=-1, discharge power are Pd; During hot stand-by duty, u=0, power loss is Pw, ignores this power loss in this model.

(5) in a dispatching cycle T, the SOC excursion is little, and maximum discharges and recharges power and keeps constant, is respectively Pcmax and Pdmax.

(6) ignore the via net loss of transformer and circuit in this model, only count by what PCS and BP caused and discharge and recharge loss, represent with efficiency for charge-discharge η c and η d.

(7) construction cost of the battery pack of one species is identical, ignores discount rate.

(8) wherein Pi is the power that i independent adjustable battery pack injected electrical network, and when battery was in the charging operating state, Pi was for just; When battery was in the discharge operating state, Pi was for negative.

(9) Mathematical Modeling provided by the invention considers that the high frequency of charging and discharging state changes the impact on the battery pack life-span, counts target function with penalty term.

(10) the power dispatching principle of energy-accumulating power station.Be generally priority scheduling active power, discharge and recharge at energy-accumulating power station in the situation of power and capacity permission, by electrical network requirement scheduling reactive power.The optimization of this scheduling strategy is based upon under the precondition that energy-accumulating power station can satisfy the total activation demand, therefore provides overall power requirement in higher level's power network dispatching system

The time, regardless of the sequencing of active power and reactive power scheduling, unified optimization.

The structure of energy-accumulating power station comprises 4 groups of independence adjustable battery groups, transformer, transformer bus and energy storage monitor system power dispatching center as shown in Figure 2; On the bus of described independent adjustable battery group access step down side; Described transformer and energy storage monitor system power dispatching center communicate; Energy storage monitor system power dispatching center and power network dispatching system communicate; The battery types of independent adjustable battery group is lithium iron battery, all accesses on the bus of 10kV/380V step down side, and its power/capacity is respectively 100kW/100kWh, 100kW/150kWh, 120kW/200kWh, 100kW/250kWh.

The flow process of the economic optimization dispatching method of energy-accumulating power station provided by the invention comprises the steps: as shown in Figure 1

Step (1) initialization energy-accumulating power station data:

Energy-accumulating power station comprises independently can dispatch battery pack; Described independence can be dispatched battery pack and be drawn together the energy storage branch road; Route energy accumulation current converter PCS, battery management system BMS and battery pile BP are propped up in described energy storage; Described energy-accumulating power station data refer to energy storage type and the parameter of energy accumulation current converter PCS, battery management system BMS and battery pile BP.

Step (2) is determined independently can dispatch the group number of battery pack:

Independent adjustable battery group refers to the energy-storage battery group that battery operated state is identical in management and running, parameter synchronization changes; Determine that each independent adjustable battery group is as a control variables independently, with A _iExpression, i=1 wherein ..., N.

Step (3) is read in independently and can be dispatched the operational factor of battery pack and be uploaded to energy storage monitor system power dispatching center:

The operational factor that independently can dispatch battery pack comprises charge efficiency η _c, discharging efficiency η _d, battery minimum allow to discharge and recharge power The maximum of battery allows to discharge and recharge power

The minimum of charged value SOC, battery allows carrying capacity

The maximum of battery allows carrying capacity

With previous dispatching cycle of battery pack operating state u _i(t-1).

The independent operational factor that can dispatch battery pack is uploaded to energy storage monitor system power dispatching center, and the construction cost C that the independent group that can dispatch battery pack is counted N, battery pack input is read from database in energy storage monitor system power dispatching center simultaneously _Fl, the reactive power discharge coefficient β of permission _iWith battery pack discharge and recharge number of times r _i

Step (4) is determined Optimum Economic Optimized Operation scheme, draws the Optimum Economic Optimal Operation Model:

Determine that Optimum Economic Optimized Operation scheme comprises target function and the constraints of determining energy-accumulating power station.

1, target function

This mathematics model is minimum as optimization aim take total cost C, and control variables is taken as the active-power P of each adjustable battery group _i, reactive power Q _i, i=1, K, N.Wherein, total cost comprises fixed cost C _fWith variable cost C _rTwo parts.For energy-accumulating power station, fixed cost refers to install construction cost; Variable cost comprises operation expense C _mWith cost depletions C _l

(1) operation expense C _m: after energy-accumulating power station builds up, carry out the work such as regular or irregular inspection and maintenance, to reduce equipment fault, guarantee the availability of battery pack.Operation expense and power plant scale, battery variety, to discharge and recharge operating mode, cell degradation degree etc. relevant, introduces aging coefficient α and operation maintenance coefficient k _r

$C_m=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}[({\&Integral;}_0^T{k}_{\mathrm{ri}}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;\mathrm{dt})\&CenterDot;{(1+\mathrm{\&alpha;})}^{r_i/R_i}]$

$=T\&CenterDot;\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}\left[k_{\mathrm{ri}}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;{(1+\mathrm{\&alpha;})}^{r_i/R_i}\right]$ ①；

In the formula, T is dispatching cycle; k _RiBe respectively i and organize independent adjustable battery group operation maintenance coefficient (unit/kWh); P _ItAnd Q _ItMeritorious and the reactive power for the scheduling of independent adjustable battery group; r _iAnd R _iBeing respectively i organizes independent adjustable battery group and has has discharged and recharged number of times and admissible global cycle number of times; Aging coefficient α can according to the ambient environmental conditions value, for example get α=1.

(2) cost depletions C _lIn the process of meritorious scheduling, consider that energy-storage system (battery pack and PCS) has certain power loss in charge and discharge process, introduce charge efficiency η _cWith discharging efficiency η _dAs certain independent adjustable battery group A _iDuring charging, the electric weight recruitment is in its certain dispatching cycle:

$\mathrm{\&Delta;}{E}_i={\&Integral;}_0^T{\mathrm{\&eta;}}_{\mathrm{ci}}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\mathrm{dt}={\mathrm{\&eta;}}_{\mathrm{ci}}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;\mathrm{<figure-callout\; id="3"\; label="T"\; filenames="HDA00002391906100022.png"\; state="\{\{state\}\}">T</figure-callout>}$ ③；

When discharge, the electric weight recruitment is in certain dispatching cycle:

$\mathrm{\&Delta;}{E}_{\text{i}}={\&Integral;}_0^T(\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}/{\mathrm{\&eta;}}_{\mathrm{di}})\mathrm{dt}=\frac{\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;T}{{\mathrm{\&eta;}}_{\mathrm{di}}}$ ④；

Then cost depletions is

In the formula, k _lBe battery pack electric energy loss coefficient (unit/kWh).

(3) fixed cost C _fThe construction cost C of arbitrary adjustable battery group _FiWith discharge and recharge global cycle number of times R _iDetermine, suppose that battery is through R _iInferiorly scrap after discharging and recharging operation, ignore its salvage value, then can be with fixing construction cost C _FiAll assign to R _iInferior independently discharges and recharges in the operation.Suppose once independently to discharge and recharge operation and can reduce battery pack fixed cost C _Fi/ R _i, and in certain dispatching cycle battery pack be in not charge mode or charge and discharge mode identical with a upper dispatching cycle, can think that then the fixed cost of this of internal consumption is zero dispatching cycle.Whether model is introduced becomes the flag bit ρ that once independently discharges and recharges behavior _i:

${\mathrm{\&rho;}}_i=\left\{\begin{array}{cc}0& u_i(t-1)\&CenterDot;u_i\left(t\right)=1\\ 1& \mathrm{else}\end{array}\right.$ ⑤；

Then interior fixed cost consumption dispatching cycle is:

$C_f=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&rho;}}_i\&CenterDot;C_{\mathrm{fi}}}{R_i}$ ⑥；

Therefore, the general objective function is:

min C＝C _m+C _l+C _f ⑦。

2. constraints

(1) power-balance constraint.The total activation demand power should be correct distribute to each and independent can dispatch battery pack, have power equation

$\left\{\begin{array}{c}{P}_{\mathrm{total}}=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{P}_i\\ Q_{\mathrm{total}}=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{Q}_i\end{array}\right.$ ⑧；

In the formula, P _TotalAnd Q _TotalBe respectively total activation active power demand and reactive power demand (kW), batteries charging is for just.

(2) power of battery constraint.Battery charging and discharging power is limited by self-condition, should satisfy certain bound scope.

During charging, u _i=1, P _iFor just, $P_{\mathrm{ci}}^{\min }\&le;P_i\&le;P_{\mathrm{ci}}^{\max }$ ⑨；

During discharge, u _i=-1, P _iFor negative, $P_{\mathrm{di}}^{\min }\&le;-P_i\&le;P_{\mathrm{di}}^{\mathrm{<figure-callout\; id="10"\; label="max"\; filenames="HDA00002391906100031.png"\; state="\{\{state\}\}">max</figure-callout>}}$ ⑩；

In the formula, With

Be respectively i and organize minimum and the maximum charge active power (kW) of independent adjustable battery,

With Be respectively i and organize minimum and the maximum discharge active power (kW) of independent adjustable battery.

Also should satisfy for system's gross power:

In the formula,

With

The minimum and the maximum that are respectively the i Battery pack always discharge and recharge power.

Sometimes, in order to satisfy the requirement of battery pack economical operation, limit the idle size that discharges and recharges power and be no more than set point (battery pack is absorbing reactive power not generally, only sends reactive power Q _i, be taken as negative), that is:

In the formula, factor beta _i≤ 1, for allowing to discharge idle coefficient.

(3) carrying capacity constraint.In the charge and discharge cycles process of battery, the energy that inside battery is stored needs within self allowed band, that is:

In the formula,

With

Be respectively minimum and maximum carrying capacity that the i Battery pack allows.

The total activation optimized mathematical model of energy-accumulating power station is as follows:

$\begin{array}{cc}\min & C=C_m\end{array}+C_l+C_f$

$=T\&CenterDot;\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}\left[k_{\mathrm{ri}}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;{(1+\mathrm{\&alpha;})}^{r_i/R_i}\right]$

$+k_{l}T\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}[(1-\mathrm{\&eta;})\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}]+\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&rho;}}_i\&CenterDot;C_{\mathrm{fi}}}{R_i}$

Wherein, $P_{\mathrm{total}}=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{P}_i$

$Q_{\mathrm{total}}=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{Q}_i$

$S_i^{\min }\&le;\sqrt{{\mathrm{<figure-callout\; id="2"\; label="P\; i"\; filenames="HDA00002391906100022.png"\; state="\{\{state\}\}">P</figure-callout>}}_i^{}+{\mathrm{<figure-callout\; id="2"\; label="Q\; i"\; filenames="HDA00002391906100022.png"\; state="\{\{state\}\}">Q</figure-callout>}}_i^{}}\&le;S_i^{\max }$

${\mathrm{\&beta;}}_i\&CenterDot;S_i^{\min }\&le;-Q_i\&le;{\mathrm{\&beta;}}_i\&CenterDot;S_i^{\max }$

${\mathrm{SOC}}_i^{\min }\&le;{\mathrm{SOC}}_i\&le;{\mathrm{SOC}}_i^{\max }$

$\mathrm{\&Delta;}{E}_i=\mathrm{\&eta;}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;T$

${\mathrm{\&rho;}}_i=\left\{\begin{array}{cc}0& u_i(t-1)\&CenterDot;u_i\left(t\right)=1\\ 1& \mathrm{else}\end{array}\right.$

Wherein:

1) control variables is for discharging and recharging power P _iAnd Q _i, i=1 ..., N, 2N altogether.When energy-accumulating power station only carries out the active power scheduling, get Q _i=0, Optimized model dimensionality reduction then, control variables becomes N.

2) data that derive from PCS, BMS comprise:

η _c-charge efficiency;

η _d-discharging efficiency;

The minimum of the-the i Battery pack allows to discharge and recharge power (kVA);

The maximum of the-the i Battery pack allows to discharge and recharge power (kVA);

SOC-charged value (kWh);

The minimum of the-the i Battery pack allows carrying capacity (kWh);

The maximum of i Battery pack allows carrying capacity (kWh);

U (t-1) front dispatching cycle of battery pack operating state;

3) can know following data according to situation and the empirical data of each battery pack:

k _Ri-battery pack operation maintenance coefficient (unit/kWh);

α-aging coefficient;

k _l-battery pack electric energy loss coefficient (unit/kWh).

4) derive from higher level control centre data:

T-dispatching cycle;

P _Total-scheduling active power aggregate demand (kW);

Q _Total-scheduling reactive power aggregate demand (kvar).

5) derive from the data of background data base:

N-available the battery pack that can independently dispatch sum;

C _FlThe construction cost (unit) that-battery pack drops into;

β _iThe reactive power discharge coefficient of-permission.

r _i-battery pack has discharged and recharged number of times.

If part energy storage branch road breaks down, will cause the energy storage branch road out of service or fall and hold to use, revise learning model in requisition for logarithm:

If i i organizes independent adjustable battery group integral body and breaks down, then should be out of service, after keeping in repair, drop into again.Between age at failure, this independent adjustable battery group is not controlled, and should remove by force corresponding control variables Pi and Q _i, the control variables dimension subtracts 1.

Certain battery branch road breaks down in the independent adjustable battery group if ii i organizes, and out of service the waiting of this fault branch keeped in repair, and the remaining power group still can continue operation in this independent adjustable battery group, but all parameters of corresponding this independent adjustable battery group should be done to fall to hold and process.After the parameter correction, Optimal Operation Model is constant.

The power dispatching instruction of step (5) output energy-accumulating power station battery pack.

Embodiment

One) be each parameter assignment shown in following table 1-table 3:

Table 1 is the identical preset parameter of each independent adjustable battery group

Table 2 is the different preset parameter of each independent adjustable battery group, on-fixed parameter

Table 3 is the on-fixed parameter of each independent adjustable battery group

Two) the constraints value is as follows:

I, Get (P _NiBe the rated power of independent adjustable battery group, i ∈ 1,2,3,4});

II, Get

(P _NiBe the rated power of independent adjustable battery group, i ∈ 1,2,3,4});

III、 ${\mathrm{SOC}}_i^{\min }\&le;{\mathrm{SOC}}_i\&le;{\mathrm{SOC}}_i^{\max },$ Get ${\mathrm{SOC}}_i^{\min }=20\%,$ ${\mathrm{SOC}}_i^{\max }=100\%,$ i∈{1,2,3,4}；

IV,

P in the formula _iThe power that charges and discharge for independent adjustable battery group.

Three) configuration scheduling cycle T=5min has carried out the emulation of the scheduling of 5 consecutive periods, result such as table 4.

Simulation result table in table 4 T dispatching cycle

Simulation result shows:

A, in arbitrary dispatching cycle, all can reach the requirement of scheduling, namely satisfy

Independent adjustable battery group all can satisfy the power constraint condition that discharges and recharges in B, each dispatching cycle:

$P_{\mathrm{di}}^{\min }\&le;-P_i\&le;P_{\mathrm{di}}^{\max },$ As shown in Figure 3.

The situation of change of the carrying capacity SOC of independent adjustable battery group all can satisfy the constraints of carrying capacity as shown in Figure 4 in C, each dispatching cycle: ${\mathrm{SOC}}_i^{\min }\&le;{\mathrm{SOC}}_i\&le;{\mathrm{SOC}}_i^{\max }.$

D, the total cost in relatively different dispatching cycles are seen: next dispatching cycle is when changing without charging and discharging state, the total cost less; When next dispatching cycle and the variation of generation of last cycle charging and discharging state, total cost is relatively large.The impact of frequent switching charging and discharging state on total cost that this has shown this scheduling strategy effecting reaction.

The present invention proposes the power dispatching optimization method take the lowest cost as target, verified by simulation example and the feasibility of energy storage branch power Optimized Operation realized the economic dispatch optimization of energy-accumulating power station.

Should be noted that at last: above embodiment is only in order to illustrate that technical scheme of the present invention is not intended to limit, although with reference to above-described embodiment the present invention is had been described in detail, those of ordinary skill in the field are to be understood that: still can make amendment or be equal to replacement the specific embodiment of the present invention, and do not break away from any modification of spirit and scope of the invention or be equal to replacement, it all should be encompassed in the middle of the claim scope of the present invention.

Claims (17)

1. the economic optimization dispatching method of an energy-accumulating power station, the system that described method is used comprises independent adjustable battery group, transformer, transformer bus and energy storage monitor system power dispatching center; On the bus of described independent adjustable battery group access step down side; Described transformer and described energy storage monitor system power dispatching center communicate; Described energy storage monitor system power dispatching center and power network dispatching system communicate;

It is characterized in that described method comprises the steps:

(1) initialization energy-accumulating power station data;

(2) determine independently can dispatch the group number of battery pack;

(3) reading in described independence can dispatch the operational factor of battery pack and be uploaded to energy storage monitor system power dispatching center;

(4) determine Optimum Economic Optimized Operation scheme, draw the Optimum Economic Optimal Operation Model;

(5) the power dispatching instruction of output energy-accumulating power station battery pack.

2. economic optimization dispatching method as claimed in claim 1 is characterized in that, in the described step (1), described energy-accumulating power station comprises independently can dispatch battery pack; Described independence can be dispatched battery pack and be drawn together the energy storage branch road; Route energy accumulation current converter PCS, battery management system BMS and battery pile BP are propped up in described energy storage; Described energy-accumulating power station data refer to energy storage type and the parameter of energy accumulation current converter PCS, battery management system BMS and battery pile BP.

3. economic optimization dispatching method as claimed in claim 1 is characterized in that, in the described step (2), described independent adjustable battery group refers to the energy-storage battery group that battery operated state is identical in management and running, parameter synchronization changes; Determine that each independent adjustable battery group is as a control variables independently, with A _iExpression, i=1 wherein ..., N.

4. economic optimization dispatching method as claimed in claim 1 is characterized in that, in the described step (3), the operational factor that described independence can be dispatched battery pack comprises charge efficiency η _c, discharging efficiency η _d, battery minimum allow to discharge and recharge power

The maximum of battery allows to discharge and recharge power

The minimum of charged value SOC, battery allows carrying capacity The maximum of battery allows carrying capacity

With previous dispatching cycle of battery pack operating state u _i(t-1).

5. economic optimization dispatching method as claimed in claim 4, it is characterized in that, the independent operational factor that can dispatch battery pack is uploaded to energy storage monitor system power dispatching center, and the construction cost C that the independent group that can dispatch battery pack is counted N, battery pack input is read from database in energy storage monitor system power dispatching center simultaneously _Fl, the reactive power discharge coefficient β of permission _iWith battery pack discharge and recharge number of times r _i

6. economic optimization dispatching method as claimed in claim 1 is characterized in that, in the described step (4), determines that Optimum Economic Optimized Operation scheme comprises target function and the constraints of determining energy-accumulating power station.

7. economic optimization dispatching method as claimed in claim 6 is characterized in that, the target function of economic optimization scheduling scheme is minimum as optimization aim take total cost C, and control variables is taken as the active-power P of battery pack _iAnd reactive power Q _i, wherein: i=1 ..., N; Described total cost C comprises fixed cost C _fWith variable cost C _rAt energy-accumulating power station, fixed cost refers to install construction cost; Variable cost comprises operation expense C _mWith cost depletions C _l

8. economic optimization dispatching method as claimed in claim 7 is characterized in that, described operation expense C _mRepresent with following formula:

$C_m=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}[({\&Integral;}_0^T{k}_{\mathrm{ri}}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;\mathrm{dt})\&CenterDot;{(1+\mathrm{\&alpha;})}^{r_i/R_i}]$

$=T\&CenterDot;\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}\left[k_{\mathrm{ri}}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;{(1+\mathrm{\&alpha;})}^{r_i/R_i}\right]$ ①；

In the formula: T is dispatching cycle; k _RiBe that i organizes independent adjustable battery group operation maintenance coefficient, unit is unit/kWh; P _ItAnd Q _ItMeritorious and the reactive power for the scheduling of independent adjustable battery group; r _iAnd R _iBe respectively i and organize the global cycle number of times that independent adjustable battery group has discharged and recharged number of times and permission; α is aging coefficient, gets α=1.

9. economic optimization dispatching method as claimed in claim 7 is characterized in that, described cost depletions C _lRepresent with following expression formula group:

In the formula: k _lBe battery pack electric energy loss coefficient, unit is unit/kWh;

As independent adjustable battery group A _iDuring charging, T electric weight recruitment is in its dispatching cycle:

$\mathrm{\&Delta;}{E}_i={\&Integral;}_0^T{\mathrm{\&eta;}}_{\mathrm{ci}}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\mathrm{dt}={\mathrm{\&eta;}}_{\mathrm{ci}}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;T$ ②；

As independent adjustable battery group A _iDuring discharge, the interior electric weight recruitment of its dispatching cycle of T is:

$\mathrm{\&Delta;}{E}_{\text{i}}={\&Integral;}_0^T(\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}/{\mathrm{\&eta;}}_{\mathrm{di}})\mathrm{dt}=\frac{\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;T}{{\mathrm{\&eta;}}_{\mathrm{di}}}$ ④；

In the formula: η _cBe charge efficiency; η _dBe discharging efficiency.

10. economic optimization dispatching method as claimed in claim 7 is characterized in that, in energy-accumulating power station, judges that whether battery pack is called the flag bit that once independently discharges and recharges behavior is ρ _i, represent with following formula:

${\mathrm{\&rho;}}_i=\left\{\begin{array}{cc}0& u_i(t-1)\&CenterDot;u_i\left(t\right)=1\\ 1& \mathrm{else}\end{array}\right.$ ⑤；

In the formula: u _i(t) be current dispatching cycle T battery pack operating state; u _i(t-1) be previous dispatching cycle of battery pack operating state;

Described fixed cost C _fRepresent with following formula:

$C_f=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&rho;}}_i\&CenterDot;C_{\mathrm{fi}}}{R_i}$

In the formula: C _FiConstruction cost for arbitrary independent adjustable battery group; R _iBe that i organizes the global cycle number of times that independent adjustable battery group discharges and recharges permission.

11. economic optimization dispatching method as claimed in claim 7 is characterized in that, the target function of economic optimization scheduling scheme represents with following formula:

min C＝C _m+C _l+C _f ⑦。

12. economic optimization dispatching method as claimed in claim 6 is characterized in that, the constraints of economic optimization scheduling scheme comprises power-balance constraint, battery charging and discharging power constraint and carrying capacity constraint.

13. economic optimization dispatching method as claimed in claim 12 is characterized in that, described power-balance constraint represents with following formula:

$\left\{\begin{array}{c}{P}_{\mathrm{total}}=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{P}_i\\ Q_{\mathrm{total}}=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{Q}_i\end{array}\right.$ ⑧；

In the formula: P _TotalAnd Q _TotalBe respectively total activation active power demand and reactive power demand, unit is kW, and batteries charging is for just.

14. economic optimization dispatching method as claimed in claim 12 is characterized in that, the bound scope of described battery charging and discharging power is as follows:

During charging, u _i=1, P _iFor just, $P_{\mathrm{ci}}^{\min }\&le;P_i\&le;P_{\mathrm{ci}}^{\max };$ ⑨；

During discharge, u _i=1, P _iFor negative, $P_{\mathrm{di}}^{\min }\&le;-P_i\&le;P_{\mathrm{di}}^{\max };$ ⑩；

In the formula,

With

Be respectively i and organize minimum and the maximum charge active power of independent adjustable battery, unit is kW,

With

Be respectively i and organize minimum and the maximum discharge active power of independent adjustable battery, unit is kW;

The power that discharges and recharges of energy-accumulating power station satisfies following formula:

In the formula:

With

The minimum and the maximum that are respectively the i Battery pack always discharge and recharge power;

In the battery set charge/discharge process, reactive power satisfies following formula:

In the formula: β _iFor allowing to discharge idle coefficient, β _i≤ 1;-Q _iThe reactive power of sending for battery pack.

15. economic optimization dispatching method as claimed in claim 12 is characterized in that, described carrying capacity constraint represents with following formula:

In the formula:

With

Be respectively minimum and maximum carrying capacity that the i Battery pack allows.

16. economic optimization dispatching method as claimed in claim 6 is characterized in that, described Optimum Economic Optimal Operation Model represents with following expression formula group:

$\begin{array}{cc}\min & C=C_m\end{array}+C_l+C_f$

$=T\&CenterDot;\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}\left[k_{\mathrm{ri}}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;{(1+\mathrm{\&alpha;})}^{r_i/R_i}\right]$

$+k_{l}T\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}[(1-\mathrm{\&eta;})\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}]+\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}\frac{{\mathrm{\&rho;}}_i\&CenterDot;C_{\mathrm{fi}}}{R_i}$

Wherein, $P_{\mathrm{total}}=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{P}_i$

$Q_{\mathrm{total}}=\underset{i=1}{\overset{N}{\mathrm{\&Sigma;}}}{Q}_i$

$S_i^{\min }\&le;\sqrt{P_i^2+Q_i^2}\&le;S_i^{\max }$

${\mathrm{\&beta;}}_i\&CenterDot;S_i^{\min }\&le;-Q_i\&le;{\mathrm{\&beta;}}_i\&CenterDot;S_i^{\max }$

${\mathrm{SOC}}_i^{\min }\&le;{\mathrm{SOC}}_i\&le;{\mathrm{SOC}}_i^{\max }$

$\mathrm{\&Delta;}{E}_i=\mathrm{\&eta;}\&CenterDot;\sqrt{P_{\mathrm{it}}^2+Q_{\mathrm{it}}^2}\&CenterDot;T$

${\mathrm{\&rho;}}_i=\left\{\begin{array}{cc}0& u_i(t-1)\&CenterDot;u_i\left(t\right)=1\\ 1& \mathrm{else}\end{array}\right.$

17. such as each described economic optimization dispatching method among the claim 1-16, it is characterized in that, when the energy storage branch road of energy-accumulating power station breaks down in the described method, the Optimum Economic Optimal Operation Model revised in the following manner:

1) if i organizes independent adjustable battery group integral body to break down, then out of service, after keeping in repair, come into operation again; Remove by force the control variables P that i organizes independent adjustable battery group _iAnd Q _i, the control variables dimension subtracts 1;

2) certain energy storage branch road breaks down in the independent adjustable battery group if i organizes, and out of service the waiting of this fault energy storage branch road keeped in repair, and the remaining power group continues operation in this independent adjustable battery group, and all parameters that i is organized independent adjustable battery group are done to fall to hold and processed; After carrying out the parameter correction, Optimal Operation Model is constant.

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