CN103280833A - Method for controlling power distribution network based on energy storage and photovoltaic coordination of active mechanism - Google Patents

Abstract

The invention discloses a method for controlling a power distribution network based on the energy storage and photovoltaic coordination of an active mechanism. The method is used for connecting a photovoltaic energy storage and power generating unit and an energy storage system into a power distribution network and comprises the following processes of establishing the optimal benefit function of the photovoltaic energy storage and power generating unit and the optimal global benefit function of the global power distribution network; respectively collecting absolute terms in the two functions; determining the optimal benefit target of the photovoltaic energy storage and power generating unit and the global benefit function of the power distribution network through combined iteration; and predicting the power generating power of the photovoltaic energy storage and power generating unit according to historical data, and guiding energy storage, charging and discharging. Automatic optimizing control is realized over the photovoltaic energy storage and power generating unit and energy storage to obtain a mode for optimizing the running of the power distribution network. The benefit rate of connecting the photovoltaic power generating unit into the network is increased.

Description

The power distribution network control method of coordinating based on the energy storage of active mechanisms and photovoltaic

Technical field

The present invention relates to intelligent power distribution net field for the coordination control of active power distribution network photovoltaic and energy storage, the present invention proposes the power distribution network control method of a kind of energy storage based on active mechanisms and photovoltaic coordination.

Background technology

Initiatively power distribution network with its flexibly, characteristics such as compatibility and optimization, be the effective solution that following power distribution network realizes the distributed photovoltaic energy storing and electricity generating unit (DG) of a large amount of accesses is carried out active management.

Photo-voltaic power supply is subjected to factor affecting such as illumination big in being incorporated into the power networks, and cooperates energy storage can weaken the adverse effect that environmental factor is brought preferably.But in definite operational mode, participate in the distribution power dispatching and aspect energy storage in the system cooperates, lack economic flexibly strategy.

At present, the control technology that is incorporated into the power networks for photovoltaic and energy storage mainly contains:

(1) research photovoltaic and energy storage cogeneration technology make power output stable, and power quality indexs such as voltage meet the regulation that is incorporated into the power networks.

(2) simple economy of having studied new forms of energy and energy storage is dispatched.The present invention exert oneself by the active optimizing of light storage photovoltaic energy storing and electricity generating unit and with the system stored energy cooperation, the unified on-road efficiency of considering photovoltaic energy storing and electricity generating unit and system stored energy is taken into account overall situation operation optimum.

(3) technology that discharges and recharges of energy-storage battery in the research system, discharge and recharge the margin of safety ability is provided under strategy, the state of emergency, and under nominal situation, energy storage is participated in the grid power balance as load or constant-power power source.

(4) research energy storage, the index that photovoltaic is relevant are estimated its function and technical merit.

Summary of the invention

In order to overcome the defective of prior art, the invention provides the power distribution network control method that a kind of energy storage based on active mechanisms and photovoltaic are coordinated, this power distribution network overall situation comprises photovoltaic energy storing and electricity generating unit and system stored energy, described photovoltaic energy storing and electricity generating unit comprise photovoltaic and with the energy storage of its coupling, it is characterized in that this method may further comprise the steps:

Set up energy storage for holding price benefit subfunction

Subfunction is compared in light storage output

$\mathrm{Exrai}\left(P_{\mathrm{psi}}\right)=\frac{{\∫}_{t_{\mathrm{pv}0}}^{t_{\mathrm{pv}1}}\mathrm{Ppvi}\·\mathrm{dt}}{{\∫}_{t_{\mathrm{sto}0}}^{t_{\mathrm{sto}1}}\mathrm{Pstoi}\·\mathrm{dt}},$ Light storage generating depletion rate subfunction $\mathrm{Dep}=\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{L}_{\mathrm{PSi}}\left(P_{\mathrm{psi}}\right)}{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{C}_{\mathrm{dei}}},$ Photovoltaic energy utility ratio subfunction

Pro wherein _i(t _Stoi) be with generator unit energy storage t discharge time _StoiBe the cycle profit function of the photovoltaic energy storing and electricity generating unit of variable, C _24iBe the operating cost of photovoltaic energy storing and electricity generating unit in one-period, Ppvi is that the photovoltaic part in the photovoltaic energy-storage units is the force function that of variable with time, Pstoi is that the energy storage section in the unit is the power output function of variable with time, and t is the beginning and ending time of photovoltaic and the output of energy storage power, L _PSi(P _Psi) be that i group photovoltaic energy storing and electricity generating unit is with this unit power output P _PsiBe the loss of variable, C _DeiBe the equipment total cost of i group photovoltaic energy storing and electricity generating unit, P _LoadBe the system loading function of a photo-voltaic power supply in the cycle of operation;

Set up the optimum benefit function E in described photovoltaic energy storing and electricity generating unit _Ffi(t _Stoi, P _Psi)=α C _i(t _Stoi)+β Dep _i(P _Psi)+γ Exrai (P _Psi) and the optimum overall benefit function of the described power distribution network overall situation $f\left(P_{\mathrm{ssi}}\right)=\frac{a\·P_{\mathrm{loss}}\left(P_{\mathrm{ssi}}\right)}{P_{\mathrm{load}}}+(-1)b\·\mathrm{Ura},$

Represented that the loss of distribution network systems accounts for the ratio of total load, with the system stored energy power P _SsiBe variable; Wherein α, β, γ are respectively price benefit, depletion rate, light storage output than the weight coefficient when estimating comprehensive benefit, and a, b are the weight coefficient of optimum overall benefit function;

Determine weight coefficient α, β, γ and a, b in the optimum overall benefit function of the optimum benefit function in described photovoltaic energy storing and electricity generating unit and the described power distribution network overall situation respectively;

Go out the optimum benefit target in photovoltaic energy storing and electricity generating unit and described power distribution network overall situation benefit target by the associating iterative;

Wherein said photovoltaic energy storing and electricity generating unit is predicted the generated output of described photovoltaic according to historical data and is instructed described energy storage discharge according to historical data.

Preferably, accurately exerted oneself by its energy storage short time of real-time control in described photovoltaic energy storing and electricity generating unit.

Preferably, the constraints of the optimum benefit function in described photovoltaic energy storing and electricity generating unit comprises parameter and the range of operation of photovoltaic and energy storage, and described photovoltaic energy storing and electricity generating unit is completely sent out or stopped transport and all can carry in the scope in system.

Preferably, the constraints of the optimum overall benefit function of the described power distribution network overall situation comprises the device parameter of described system stored energy and moves limit value, system load flow, each node voltage limit value, other distributed power source power limit and capacity of trunk.

Preferably, it adopts the optimum overall benefit function that replaces the optimum benefit function in the described photovoltaic energy storing and electricity generating of iterative unit and the described power distribution network overall situation to obtain parameter P _Ssi, t _Stoi, P _PsiValue.

Compared with prior art, beneficial effect of the present invention is as follows:

1, the present invention achieves a butt joint into the autonomous optimal control of the photovoltaic energy storing and electricity generating unit of power distribution network, formulates to be incorporated into the power networks substantially according to historical data to ensure that from the net strategy its power output is stable;

2, the present invention has considered the optimum way of system stored energy in the active power distribution network that inserts the photovoltaic energy-storage units, takes full advantage of the operation of control system energy storage regulating system, improves the earning rate that photovoltaic utilizes level and photovoltaic energy storing and electricity generating unit;

3, the present invention has considered that the goal coordination of photovoltaic energy storing and electricity generating unit and system stored energy moves coordination with realization, reaches the global optimum that both take into account.

Certainly, implement arbitrary product of the present invention and might not need to reach simultaneously above-described all advantages.

Description of drawings

Fig. 1 is the power distribution network schematic diagram that the energy storage based on active mechanisms provided by the invention and photovoltaic are coordinated;

Fig. 2 is that the control schematic diagram is coordinated in photovoltaic energy storing and electricity generating provided by the invention unit;

Fig. 3 is power distribution network global coordination control schematic diagram provided by the invention.

Embodiment

The present invention will be further described with specific embodiment by reference to the accompanying drawings in the below.

Embodiment

The invention provides the power distribution network control method that a kind of energy storage based on active mechanisms and photovoltaic are coordinated, this power distribution network overall situation comprises photovoltaic energy storing and electricity generating unit and system stored energy, described photovoltaic energy storing and electricity generating unit comprise photovoltaic and with the energy storage of its coupling, it is characterized in that this method may further comprise the steps:

Set up energy storage for holding price benefit subfunction

Subfunction is compared in light storage output $\mathrm{Exrai}\left(P_{\mathrm{psi}}\right)=\frac{{\∫}_{t_{\mathrm{pv}0}}^{t_{\mathrm{pv}1}}\mathrm{Ppvi}\·\mathrm{dt}}{{\∫}_{t_{\mathrm{sto}0}}^{t_{\mathrm{sto}1}}\mathrm{Pstoi}\·\mathrm{dt}},$ Light storage generating depletion rate subfunction $\mathrm{Dep}=\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{L}_{\mathrm{PSi}}\left(P_{\mathrm{psi}}\right)}{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{C}_{\mathrm{dei}}},$ Photovoltaic energy utility ratio subfunction

Pro wherein _i(t _Sto) be with generator unit energy storage t discharge time _StoiBe the cycle profit function of the photovoltaic energy storing and electricity generating unit of variable, C _24iBe the operating cost of photovoltaic energy storing and electricity generating unit in one-period, Ppv is that the photovoltaic part in the photovoltaic energy-storage units is the force function that of variable with time, Psto is that the energy storage section in the unit is the power output function of variable with time, and t is the beginning and ending time of photovoltaic and the output of energy storage power, L _PSi(P _Psi) be that i group photovoltaic energy storing and electricity generating unit is with this unit power output P _PsiBe the loss of variable, C _DeiBe the equipment total cost of i group photovoltaic energy storing and electricity generating unit, P _LoadBe the system loading function of a photo-voltaic power supply in the cycle of operation;

Set up the optimum benefit function E in described photovoltaic energy storing and electricity generating unit _Ffi(t _Stoi, P _Psi)=α C _i(t _Stoi)+β Dep _i(P _Psi)+γ Exrai (P _Psi) and the optimum overall benefit function of the described power distribution network overall situation $f\left(P_{\mathrm{ssi}}\right)=\frac{a\·P_{\mathrm{loss}}\left(P_{\mathrm{ssi}}\right)}{P_{\mathrm{load}}}+(-1)b\·\mathrm{Ura},$ Represented that the loss of distribution network systems accounts for the ratio of total load, with the system stored energy power P _SsiBe variable; Wherein α, β, γ are respectively price benefit, depletion rate, light storage output than the weight coefficient when estimating comprehensive benefit, and a, b are the weight coefficient of optimum overall benefit function;

Determine weight coefficient α, β, γ and a, b in the optimum overall benefit function of the optimum benefit function in described photovoltaic energy storing and electricity generating unit and the described power distribution network overall situation respectively;

Go out the optimum benefit target in photovoltaic energy storing and electricity generating unit and described power distribution network overall situation benefit target by the associating iterative;

Wherein said photovoltaic energy storing and electricity generating unit is predicted the generated output of described photovoltaic according to historical data and is instructed described energy storage discharge according to historical data.

As shown in Figure 2, at E _Ffi(t _Stoi, P _Psi)=α C _i(t _Stoi)+β Dep _i(P _Psi)+γ Exrai (P _Psi) middle C _l(t _Sto) be with photovoltaic energy storing and electricity generating unit energy storage t discharge time _StoiBe the benefit function of variable, Dep _i(P _Psi) be the power output P with photovoltaic energy storing and electricity generating unit _PsiLight storage generating depletion rate function for variable, Exrai is that function is compared in light storage output, α, β, γ are respectively price benefit, depletion rate, light storage output than the weight coefficient when estimating comprehensive benefit, and α, β, γ obtain at the benefit demand that photovoltaic energy storing and electricity generating unit is in operation.

In, Pro _i(t _Stoi) be the cycle profit of photovoltaic energy storing and electricity generating unit, C _24iBe the operating cost of photovoltaic energy storing and electricity generating unit in one-period.

Ppv is that the photovoltaic part in the photovoltaic energy-storage units is the force function that of variable with time, Pstoi is that the energy storage section in the unit is the power output function of variable with time, t is the beginning and ending time of photovoltaic and the output of energy storage power, and Ppvi and Pstoi obtain according to historical data.

In, L _PSi(P _Psi) be that i group photovoltaic energy storing and electricity generating unit is with this unit power output P _PsiLoss for variable; C _DeiBe the equipment total cost of i group photovoltaic energy storing and electricity generating unit, be known parameters.

As shown in Figure 3, exist $f\left(P_{\mathrm{ssi}}\right)=\frac{a\·P_{\mathrm{loss}}\left(P_{\mathrm{ssi}}\right)}{P_{\mathrm{load}}}+(-1)b\·\mathrm{Ura}$ In,

Represented that the loss of distribution network systems accounts for the ratio of total load, with the system stored energy power P _SsiBe variable;

Be the function of photovoltaic energy utility ratio, P _LoadBe the system loading function of a photo-voltaic power supply in the cycle of operation, Ppvi is that the photovoltaic part in the photovoltaic energy-storage units is the force function that of variable with time; A, b are weight coefficient, obtain according to the real-time system operating condition.

Adopt the optimum overall benefit function that replaces the optimum benefit function in the described photovoltaic energy storing and electricity generating of iterative unit and the described power distribution network overall situation to obtain the optimum overall benefit target of the optimum benefit in described photovoltaic energy storing and electricity generating unit and the described power distribution network overall situation respectively, obtain parameter P _Ssi, t _Stoi, P _PsiOwing in formula 1, contain the condition P relevant for system stored energy _Ssi, in formula 2, contain the condition t relevant for photovoltaic energy storing and electricity generating unit _Stoi, P _PsiSo, can adopt alternately two groups of optimal objectives of iterative, to reach global optimum.This process has embodied photovoltaic energy storing and electricity generating unit and feature is coordinated in global sides operation between the two, is manifestation mode with the variable intersection, by balanced both on-road efficiencies of target function, reaches both optimums.

Independently predict the intermittent rule of illumination in photovoltaic energy storing and electricity generating unit according to historical data, formulation is incorporated into the power networks substantially and from the net strategy, short-term fluctuation relies on energy storage to stabilize; The photovoltaic energy-storage units is in running, and expectation can be used illumination energy to greatest extent.According to statistics, China average light according to the period be every day 9 up to 15 o'clock, this period is in peak electricity tariff interval in the tou power price, and this moment, system loading was higher.Thereby the illumination energy should be fully utilized in this period, can make photovoltaic energy storing and electricity generating cell side obtain greatest benefit.In the actual motion, photovoltaic needs according to historical data, the generated output in the cycle of operation is predicted, and can be done the short-term forecast of minute level, and the precognition power fluctuation instructs energy storage according to the unit export target, stabilizes the small size output variation that the illumination fluctuation brings.

In photovoltaic energy storing and electricity generating unit normal work period, system stored energy embodies part throttle characteristics, absorbs energy.The photovoltaic energy-storage units will be used the power flow tracing technology to the part of system stored energy power supply, be embodied in Pro _i(t _Stoi) in, with the mutual effect between the storage of reflection light and load, and estimate the income of photovoltaic energy storing and electricity generating unit in one-period.During extremely load (electricity price) low-valley interval arrives after illumination finishes, the energy storage of photovoltaic energy storing and electricity generating unit is system's power supply as the unit out-put supply, its energy derives from low-valley interval power absorbed from system as far as possible, has wherein also comprised in the period at sunshine the power supply to system stored energy.

Generally speaking, the power distribution network control method that energy storage and the photovoltaic based on active mechanisms that the present invention proposes coordinated, utilize power benefit and the utilance of photovoltaic energy-storage units, by the optimum benefit target of associating iterative photovoltaic energy-storage units and system's overall situation benefit target.The present invention has taken into full account the light storage generator unit sexual factor of having a rest running time, utilizes in generating prediction and the unit discharge of energy storage short-term to realize that the output of operating conditions stablizes; Take full advantage of the influence of system stored energy and tou power price, make photovoltaic energy storing and electricity generating unit reach single group operation income maximum.To the autonomous optimal control in photovoltaic energy storing and electricity generating unit simultaneously, consider the influence of system stored energy operational mode, and by both harmony, reduced the network line loss, improve the capacity factor of photovoltaic, reach global optimum.This method is guaranteeing fully to have used two kinds of distributed energies of photovoltaic and energy storage under the system balancing prerequisite, and can realize that coordination is controlled to the optimum under the various operation sights by to photovoltaic energy storing and electricity generating unit and the flexible adjustment of global sides to target function.

More than the disclosed preferred embodiment of the present invention just be used for helping to set forth the present invention.Preferred embodiment does not have all details of detailed descriptionthe, does not limit this invention yet and only is described embodiment.Obviously, according to the content of this specification, can make many modifications and variations.These embodiment are chosen and specifically described to this specification, is in order to explain principle of the present invention and practical application better, thereby the technical field technical staff can understand and utilize the present invention well under making.The present invention only is subjected to the restriction of claims and four corner and equivalent.

Claims (5)

1. power distribution network control method of coordinating based on the energy storage of active mechanisms and photovoltaic, this power distribution network overall situation comprises photovoltaic energy storing and electricity generating unit and system stored energy, described photovoltaic energy storing and electricity generating unit comprise photovoltaic and with the energy storage of its coupling, it is characterized in that this method may further comprise the steps:

Set up energy storage for holding price benefit subfunction Subfunction is compared in light storage output $\mathrm{Exrai}\left(P_{\mathrm{psi}}\right)=\frac{{\∫}_{t_{\mathrm{pv}0}}^{t_{\mathrm{pv}1}}\mathrm{Ppvi}\·\mathrm{dt}}{{\∫}_{t_{\mathrm{sto}0}}^{t_{\mathrm{sto}1}}\mathrm{Pstoi}\·\mathrm{dt}},$ Light storage generating depletion rate subfunction $\mathrm{Dep}=\frac{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{L}_{\mathrm{PSi}}\left(P_{\mathrm{psi}}\right)}{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{C}_{\mathrm{dei}}},$ Photovoltaic energy utility ratio subfunction

Pro wherein _i(t _Stoi) be with generator unit energy storage t discharge time _StoiBe the cycle profit function of the photovoltaic energy storing and electricity generating unit of variable, C _24iBe the operating cost of photovoltaic energy storing and electricity generating unit in one-period, Ppvi is that the photovoltaic part in the photovoltaic energy-storage units is the force function that of variable with time, Pstoi is that the energy storage section in the unit is the power output function of variable with time, and t is the beginning and ending time of photovoltaic and the output of energy storage power, L _PSi(P _Psi) be that i group photovoltaic energy storing and electricity generating unit is with this unit power output P _PsiBe the loss of variable, C _DeiBe the equipment total cost of i group photovoltaic energy storing and electricity generating unit, P _LoadBe the system loading function of a photo-voltaic power supply in the cycle of operation;

Set up the optimum benefit function E in described photovoltaic energy storing and electricity generating unit _Ffi(t _Stoi, P _Psi)=α C _i(t _Stoi)+β Dep _i(P _Psi)+γ Exrai (P _Psi) and the optimum overall benefit function of the described power distribution network overall situation $f\left(P_{\mathrm{ssi}}\right)=\frac{a\·P_{\mathrm{loss}}\left(P_{\mathrm{ssi}}\right)}{P_{\mathrm{load}}}+(-1)b\·\mathrm{Ura},$

Represented that the loss of distribution network systems accounts for the ratio of total load, with the system stored energy power P _SsiBe variable; Wherein α, β, γ are respectively price benefit, depletion rate, light storage output than the weight coefficient when estimating comprehensive benefit, and a, b are the weight coefficient of optimum overall benefit function;

Determine weight coefficient α, β, γ and a, b in the optimum overall benefit function of the optimum benefit function in described photovoltaic energy storing and electricity generating unit and the described power distribution network overall situation respectively;

Go out the optimum benefit target in photovoltaic energy storing and electricity generating unit and described power distribution network overall situation benefit target by the associating iterative;

Wherein said photovoltaic energy storing and electricity generating unit is predicted the generated output of described photovoltaic according to historical data and is instructed described energy storage discharge according to historical data.

2. the power distribution network control method of coordinating based on energy storage and the photovoltaic of active mechanisms as claimed in claim 1 is characterized in that accurately exerting oneself by its energy storage short time of real-time control in described photovoltaic energy storing and electricity generating unit.

3. energy storage and the power distribution network control method coordinated of photovoltaic based on active mechanisms as claimed in claim 1, it is characterized in that, the constraints of the optimum benefit function in described photovoltaic energy storing and electricity generating unit comprises parameter and the range of operation of photovoltaic and energy storage, and described photovoltaic energy storing and electricity generating unit is completely sent out or stopped transport and all can carry in the scope in system.

4. energy storage and the power distribution network control method coordinated of photovoltaic based on active mechanisms as claimed in claim 1, it is characterized in that the constraints of the optimum overall benefit function of the described power distribution network overall situation comprises the device parameter of described system stored energy and moves limit value, system load flow, each node voltage limit value, other distributed power source power limit and capacity of trunk.

5. as the power distribution network control method of energy storage and photovoltaic coordination based on active mechanisms as claimed in claim 1, it is characterized in that it adopts the optimum overall benefit function that replaces the optimum benefit function in the described photovoltaic energy storing and electricity generating of iterative unit and the described power distribution network overall situation to obtain parameter P _Ssi, t _Stoi, P _PsiValue.

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