CN104753076A

CN104753076A - Battery energy storage system for peak load shifting and control method thereof

Info

Publication number: CN104753076A
Application number: CN201310753869.9A
Authority: CN
Inventors: 景剑飞; 孙嘉品; 尹韶文
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2013-12-31
Filing date: 2013-12-31
Publication date: 2015-07-01
Anticipated expiration: 2033-12-31
Also published as: CN104753076B

Abstract

The invention provides a battery energy storage system for peak load shifting and a control method thereof. The system comprises M energy storage modules, wherein M energy storage modules are mutually connected in parallel, each energy storage module comprises a battery pack and a bi-directional converter, the direct current end of the bi-directional converter is connected with the battery pack, the alternating current end of the bi-directional converter is connected with a power grid, and M is the integer greater than 1; and a monitoring module, wherein the monitoring module is respectively connected with the battery pack and bi-directional converter in each energy storage module, the monitoring module is used for obtaining the charging and discharging power demand curve and current stress optical coefficients (SOC) of M battery packs, and performing the start and stop control and power distribution to M energy storage modules according to the charging and discharging power demand curve, the current SOC of M battery packs and the power-efficiency curve of each energy storage module. The system is formed by connecting multiple energy storage modules in parallel, so the peak load shifting capacity is enhanced, the stability and safety of the power grid are obviously improved, and the redundancy and applicability of the system are improved.

Description

For battery energy storage system and the control method thereof of peak load shifting

Technical field

The present invention relates to technical field of electric power, particularly the control method of a kind of battery energy storage system for peak load shifting and a kind of battery energy storage system for peak load shifting.

Background technology

Along with the development of society, demand for electric power energy constantly increases, electricity consumption concentration degree is also increasing, during the peaks of power consumption such as this will cause by day, dusk, supply of electric power is not enough, larger power shortage directly has influence on stability and the fail safe of electrical network, make increasing place have to adopt the extreme manner such as power cuts to limit consumption to ensure the stable operation of electrical network, but this brings great inconvenience also to the life of people, affect industrial production, cause larger economic loss.

In this case, various forms of energy-storage system obtains great opportunity to develop, and energy-storage system can play the effect improving power supply quality, improve grid stability by the form of peak load shifting.For other energy storage modes, the battery energy storage system being representative with lithium electronics, vanadium solution battery has convenient and swift, that energy conversion rate is high advantage, is therefore subject to increasing attention.

A kind of control mode of the battery energy storage system for power distribution network peak load shifting is proposed in correlation technique, but what it adopted is separate unit current transformer battery energy storage system, thus can limit by power voltage grade, small-power occasion can only be used for, and for the limited use of power network compensation, if break down simultaneously, then system cannot continue to run completely, and reliability is low.

Summary of the invention

Object of the present invention is intended at least solve one of above-mentioned technological deficiency.

For this reason, one object of the present invention is to propose a kind of battery energy storage system for peak load shifting, this system is composed in parallel by multiple energy-storage module, not only strengthen peak load shifting ability, can play the stability and fail safe that improve electrical network and comparatively significantly act on, and improve redundancy and the applicability of system.

Another object of the present invention is the control method proposing a kind of battery energy storage system for peak load shifting.

For achieving the above object, a kind of battery energy storage system for peak load shifting that one aspect of the present invention embodiment proposes, comprise: M energy-storage module, a described M energy-storage module is parallel with one another, each energy-storage module in a described M energy-storage module comprises battery pack and two way convertor, and the DC terminal of described two way convertor is connected with described battery pack, and the interchange end of described two way convertor is connected with electrical network, wherein, M be greater than 1 integer; Monitoring module, described monitoring module is connected with two way convertor respectively with the battery pack in described each energy-storage module, described monitoring module for obtaining the current SOC of charge-discharge power demand curve and M battery pack, and carries out on off control and power division according to the current SOC of described charge-discharge power demand curve, a described M battery pack and the power-efficient curve of described each energy-storage module to a described M energy-storage module.

According to the battery energy storage system for peak load shifting of the embodiment of the present invention, M energy-storage module is adopted to compose in parallel, the energy-storage module structure of M parallel connection is identical, and monitoring module is according to charge-discharge power demand curve, treated with a certain discrimination when the current SOC of M battery pack and the power-efficient curve of each energy-storage module carry out on off control and power division to M energy-storage module, follow " how electricity is put more, few electricity fills soon, high damage is used less, low damage is multiplex " principle, ensure the harmony of each energy-storage module battery pack to greatest extent, increase the useful life of battery pack, reduce system cost, be conducive to promoting.Simultaneously, M energy-storage module is in parallel not only because the raising of power grade enhances peak load shifting ability, the stability and security performance that improve electrical network are played and comparatively significantly acts on, and due to M energy-storage module separate, less for the normal influence on system operation of system during single energy-storage module fault, improve redundancy and the applicability of system.

For achieving the above object, the present invention on the other hand embodiment proposes a kind of control method of the battery energy storage system for peak load shifting, wherein, described battery energy storage system comprises M energy-storage module in parallel, each energy-storage module comprises battery pack and two way convertor, and M be greater than 1 integer, described control method comprises the following steps: S1, obtains the current SOC of charge-discharge power demand curve and M battery pack; S2, carries out on off control and power division according to the current SOC of described charge-discharge power demand curve, a described M battery pack and the power-efficient curve of described each energy-storage module to a described M energy-storage module.

The control method of the battery energy storage system for peak load shifting of the embodiment of the present invention, treated with a certain discrimination when on off control and power division being carried out to M energy-storage module according to charge-discharge power demand curve, the current SOC of a M battery pack and the power-efficient curve of each energy-storage module, follow " many electricity are put more, few electricity fills soon, high damage to use less, low damage is multiplex " principle, the harmony of each energy-storage module battery pack can be ensured to greatest extent, increase the useful life of battery pack, reduce system cost, be conducive to promoting.Simultaneously, M energy-storage module is in parallel not only because the raising of power grade enhances peak load shifting ability, the stability and security performance that improve electrical network are played and comparatively significantly acts on, and due to M energy-storage module separate, less for the normal influence on system operation of system during single energy-storage module fault, improve redundancy and the applicability of system.

The aspect that the present invention adds and advantage will part provide in the following description, and part will become obvious from the following description, or be recognized by practice of the present invention.

Accompanying drawing explanation

The present invention above-mentioned and/or additional aspect and advantage will become obvious and easy understand from the following description of the accompanying drawings of embodiments, wherein:

Fig. 1 is the block diagram of the battery energy storage system for peak load shifting according to the embodiment of the present invention;

Fig. 2 is the flow chart of the control method of the battery energy storage system for peak load shifting according to the embodiment of the present invention;

Fig. 3 is according to an embodiment of the invention for the flow chart of the control method of the battery energy storage system of peak load shifting;

Fig. 4 is the further flow chart of step S305 in the control method according to the battery energy storage system for peak load shifting of the present invention's specific embodiment;

Fig. 5 is the further flow chart of step S307 in the control method according to the battery energy storage system for peak load shifting of the present invention's specific embodiment.

Embodiment

Be described below in detail embodiments of the invention, the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or has element that is identical or similar functions from start to finish.Being exemplary below by the embodiment be described with reference to the drawings, only for explaining the present invention, and can not limitation of the present invention being interpreted as.

Disclosing hereafter provides many different embodiments or example is used for realizing different structure of the present invention.Of the present invention open in order to simplify, hereinafter the parts of specific examples and setting are described.Certainly, they are only example, and object does not lie in restriction the present invention.In addition, the present invention can in different example repeat reference numerals and/or letter.This repetition is to simplify and clearly object, itself does not indicate the relation between discussed various embodiment and/or setting.In addition, the various specific technique that the invention provides and the example of material, but those of ordinary skill in the art can recognize the property of can be applicable to of other techniques and/or the use of other materials.In addition, fisrt feature described below second feature it " on " structure can comprise the embodiment that the first and second features are formed as directly contact, also can comprise other feature and be formed in embodiment between the first and second features, such first and second features may not be direct contacts.

In describing the invention, it should be noted that, unless otherwise prescribed and limit, term " installation ", " being connected ", " connection " should be interpreted broadly, such as, can be mechanical connection or electrical connection, also can be the connection of two element internals, can be directly be connected, also indirectly can be connected by intermediary, for the ordinary skill in the art, the concrete meaning of above-mentioned term can be understood as the case may be.

The control method of the battery energy storage system for peak load shifting and the battery energy storage system for peak load shifting proposed according to the embodiment of the present invention is described with reference to the accompanying drawings.

Fig. 1 is the block diagram of the battery energy storage system for peak load shifting according to the embodiment of the present invention.As shown in Figure 1, this battery energy storage system being used for peak load shifting comprise M energy-storage module 101,102,103 ..., 10M and monitoring module 200.

Wherein, M energy-storage module 101,102,103 ..., 10M is parallel with one another, and each energy-storage module in M energy-storage module comprises battery pack 10 and two way convertor 20, the DC terminal of two way convertor 20 is connected with battery pack 10, the interchange end of two way convertor 20 is connected with electrical network 300, wherein, M be greater than 1 integer.

Monitoring module 200 is connected with two way convertor 20 respectively with the battery pack 10 in each energy-storage module, monitoring module 200 is for obtaining the current SOC(State Of Charge of charge-discharge power demand curve and M battery pack, state-of-charge), and according to charge-discharge power demand curve, the current SOC of a M battery pack and the power-efficient curve of each energy-storage module, on off control and power division are carried out to M energy-storage module.

In an embodiment of the present invention, the structure of M energy-storage module is identical, and the two way convertor in each energy-storage module comprises again three-phase tri-level inverter bridge, alternating current filter, isolating transformer, sample circuit, inverter controller.Described three-phase tri-level inverter bridge is IGBT module or IPM module class power electronic device, and described sample circuit comprises voltage transformer, power pack, current Hall, voltage zero-crossing detection circuit etc.Preferably, described inverter controller adopts the processor that can carry out high rate bioreactor to electric current and voltage information, such as DSP, FPGA etc.Described battery pack comprises high-capacity lithium battery or vanadium solution battery etc. can charge-discharge battery, and can be detected the SOC, electric current and voltage information, fault message etc. of battery pack in real time by battery management system.

Monitoring module 200 is connected with the inverter controller in each two way convertor, sample circuit and battery pack by communication bus, the voltage, electric current, power, capacity, running status, warning information etc. of each two way convertor of Real-Time Monitoring and battery pack; Go back the information of voltage, current information etc. of the information of voltage of Real-Time Monitoring electrical network end, current information, load end simultaneously.Further, monitoring module, according to the historical power data of monitoring and electric network data prediction load curve, obtains described charge-discharge power demand curve, and transmitting order to lower levels controls M the energy-storage module start and stop, change power stage etc. of aforementioned parallel connection.

In one embodiment of the invention, monitoring module 200 directly can also receive the described charge-discharge power demand curve of host computer and the transmission of higher level's dispatching patcher.

And, monitoring module is according to total discharge and recharge time of M battery pack, actual heap(ed) capacity, nominal heap(ed) capacity and the information such as cell decay life characteristic that obtains through great many of experiments, calculate the attenuation degree of battery and possible useful life, thus obtain the current SOC of M battery pack.

According to one embodiment of present invention, monitoring module 200 obtains the total capacity of total SOC and M battery pack of M battery pack according to the current SOC of M battery pack, and whether target requirement power when judging that battery energy storage system starts according to the total capacity of total SOC and M battery pack and described charge-discharge power demand curve is more than or equal to system charge-discharge electric power limit value, if so, be then described target requirement power with described system charge-discharge electric power limit value.Namely say, battery energy storage system start time target requirement power be more than or equal to system discharge power limit, then with system discharge power limit for target requirement power; Battery energy storage system start time target requirement power be more than or equal to system charge power limit value, then with system charge power limit value for target requirement power.

Further, monitoring module 200 calculates according to the rated power of target requirement power and each energy-storage module the quantity needing the energy-storage module carrying out work.

Further, monitoring module 200 needs the quantity of the energy-storage module carrying out work according to following formulae discovery:

N=rounds (︱ Pobj ︱/Pe)+1(1)

Wherein, N is the quantity needing the energy-storage module carrying out work, and Pobj is target requirement power, and Pe is the rated power of each energy-storage module.

That is, monitoring module 200 is just slightly determined to need to start the quantity of carrying out the energy-storage module of work according to the rated power of target requirement power and each energy-storage module, and adjusts needing to start the quantity of carrying out the energy-storage module of work according to the single charge-discharge electric power limit value of energy-storage module and target requirement power.

Particularly, in one embodiment of the invention, when target requirement power P obj is greater than 0 and needs the quantity N of the energy-storage module carrying out work to be less than M, monitoring module 200 obtains the quantity that single discharge power limit value is greater than the energy-storage module of rated power Pe, and when the quantity that single discharge power limit value is greater than the energy-storage module of described rated power Pe be more than or equal to described need the quantity N of the energy-storage module carrying out work time, monitoring module 200 controls the described quantity N of the energy-storage module carrying out work that needs and remains unchanged.

And, when the quantity that single discharge power limit value is greater than the energy-storage module of rated power Pe be less than described need the quantity N of the energy-storage module carrying out work time, the current SOC of M battery pack sorts by monitoring module 200 from big to small, and from M energy-storage module corresponding to M battery pack after sequence, choose N+1 energy-storage module from big to small according to the current SOC of M battery pack, judge whether the single discharge power limit value sum of N+1 energy-storage module is more than or equal to described target requirement power P obj, wherein, if, monitoring module 200 judges that a described N+1 energy-storage module is as the energy-storage module needing to carry out work, if not, monitoring module 200 chooses N+2 energy-storage module from big to small according to the current SOC of a described M battery pack from M energy-storage module corresponding to M battery pack after sequence, until the single discharge power limit value sum of N+i energy-storage module is more than or equal to described target requirement power P obj, wherein, i be more than or equal to 1 integer, and N+i is less than or equal to M.

That is, if Pobj>0, the startup number of units N=that monitoring module 200 calculates energy-storage module according to formula (1) rounds (Pobj/Pe)+1.Wherein, if N is more than or equal to the sum M of the energy-storage module of system, then N gets the sum M of the energy-storage module of system; If N is less than M, then judges that maximum discharge power and single discharge power limit value are greater than the number of units of the energy-storage module of Pe, if be more than or equal to N, then make N=N, namely need the quantity N of the energy-storage module carrying out work to remain unchanged; If the number of units that single discharge power limit value is greater than the energy-storage module of Pe is less than N, then according to the current SOC sequence of the battery pack in each energy-storage module, choose N=N+1 platform (if the current SOC of battery pack is identical, selecting the energy-storage module of the longer correspondence of the lower life expectancy of battery loss) from big to small, by the discharge power limit value sum of N+1 platform energy-storage module and target requirement power ratio comparatively, if Σ is Plimitd >=Pobj, N=N is made; Otherwise then make N=N+1, until Σ Plimitd >=Pobj sets up.

In another embodiment of the present invention, when described target requirement power P obj be less than 0 and described need the quantity N of the energy-storage module carrying out work to be less than M time, monitoring module 200 obtains the quantity that single charge power limit value is greater than the energy-storage module of described rated power Pe, and when the quantity that described single charge power limit value is greater than the energy-storage module of described rated power Pe be more than or equal to described need the quantity N of the energy-storage module carrying out work time, monitoring module 200 controls the described quantity N of the energy-storage module carrying out work that needs and remains unchanged.

And, when the quantity that single charge power limit value is greater than the energy-storage module of described rated power Pe be less than described need the quantity N of the energy-storage module carrying out work time, the current SOC of a described M battery pack sorts by monitoring module 200 from small to large, and from M energy-storage module corresponding to M battery pack after sequence, choose N+1 energy-storage module from small to large according to the current SOC of M battery pack, judge whether the absolute value of the single charge power limit value sum of a described N+1 energy-storage module is more than or equal to described target requirement power P obj, wherein, if, described monitoring module judges that a described N+1 energy-storage module is as the energy-storage module needing to carry out work, if not, described monitoring module chooses N+2 energy-storage module from small to large according to the current SOC of a described M battery pack from M energy-storage module corresponding to M battery pack after sequence, until the absolute value of the single charge power limit value sum of N+j energy-storage module is more than or equal to described target requirement power P obj, wherein, j be more than or equal to 1 integer, and N+j is less than or equal to M.

That is, if Pobj<0, the startup number of units N=that monitoring module 200 calculates energy-storage module according to formula (1) rounds (︱ Pobj ︱/Pe)+1.Wherein, if N is more than or equal to the sum M of the energy-storage module of system, then N gets the sum M of the energy-storage module of system; If N is less than M, then judges that maximum charge power and single charge power limit value are greater than the number of units of the energy-storage module of Pe, if be more than or equal to N, then make N=N, namely need the quantity N of the energy-storage module carrying out work to remain unchanged; If the number of units that single charge power limit value is greater than the energy-storage module of Pe is less than N, then according to the current SOC sequence of the battery pack in each energy-storage module, choose N=N+1 platform (if the current SOC of battery pack is identical, selecting the energy-storage module of the longer correspondence of the lower life expectancy of battery loss) from small to large, by the absolute value of the charge power limit value sum of N+1 platform energy-storage module and target requirement power ratio comparatively, if Σ | Plimitd| >=| Pobj|, makes N=N; Otherwise then make N=N+1, until Σ | Plimitd| >=| Pobj| sets up.

Wherein, when needing the quantity N of the energy-storage module carrying out work to be more than or equal to M, monitoring module 200 judges that a described M energy-storage module is as the described energy-storage module needing to carry out work.

In one embodiment of the invention, monitoring module also finally needs the quantity of the energy-storage module carrying out work according to the power-efficient curve calculation of each energy-storage module.Namely say, monitoring module 200 according to the total losses of the power-efficient curve of described each energy-storage module and the N number of energy-storage module of described target requirement power calculation and the total losses of N+1 energy-storage module and/or the total losses of N-1 energy-storage module to adjust the described quantity N needing the energy-storage module carrying out work.

Particularly, with during N number of energy-storage module work, power-sharing is carried out for Pn to target requirement power P obj, table look-up (the Characteristics of power efficiency table of every platform energy-storage module) to obtain the efficiency eta h=f(Ph of every platform energy-storage module according to this power); Calculate N platform total losses: P (n) loss=Σ (1-η h) * Ph, wherein h is the integer of 1 to N.If increase by 1 energy-storage module, current SOC according to battery pack in each energy-storage module distributes power, to table look-up the efficiency eta h=f (Ph) obtaining every platform according to this power, calculate N+1 platform total losses: P (n+1) loss=Σ (1-η h) * Ph, wherein h is the integer of 1 ~ N+1.If P (n+1) loss>=P (n) is loss, keep starting number of units N constant; Otherwise the current SOC sequence according to battery pack in each energy-storage module starts N=N+1 platform energy-storage module to choose.If reduce by 1 energy-storage module, current SOC according to battery pack in each energy-storage module distributes power, to table look-up the efficiency eta h=f (Ph) obtaining every platform according to this power, calculate N-1 platform total losses: P (n-1) loss=Σ (1-η h) * Ph, wherein h is the integer of 1 ~ N-1.If P (n-1) loss>=P (n) is loss, keep starting number of units N constant; Otherwise choose according to the current SOC sequence of battery pack in each energy-storage module and start N=N-1 platform.

In an embodiment of the present invention, when N number of energy-storage module carries out work, the current SOC sum of N number of battery pack that monitoring module 200 also calculates in described N number of energy-storage module is Sum(SOC)=Σ Sk, and calculate current (1-SOC) sum Sum(1-SOC of the N number of battery pack in described N number of energy-storage module)=Σ (1-Sk), wherein, Sk is current SOC, the k=1,2,3 of a kth battery pack in described N number of battery pack ... N.

According to one embodiment of present invention, when described target requirement power P obj is greater than 0, the distribution power of each energy-storage module in monitoring module 200 N number of energy-storage module according to following formulae discovery:

Pk=Pobj*Sk/（ΣSk）（2）

Wherein, Pk is the distribution power of a kth energy-storage module in described N number of energy-storage module.

Then, monitoring module 200 is when judging that the distribution power of a kth energy-storage module in described N number of energy-storage module is greater than himself discharge power limit value, monitoring module 200 judges that the distribution power of a kth energy-storage module is as himself discharge power limit value, and according to kth in following formulae discovery residue N-1 energy-storage module ' the distribution power of individual energy-storage module:

Pk’=（Pobj-Pk）*Sk’/（ΣSk-Sk）（3）

Wherein, Pk ' is current SOC, the k of the kth distribution power of the individual energy-storage module ', Sk ' is kth in a described N-1 battery pack ' individual battery pack in described N-1 the energy-storage module calculated '=1,2,3 ... N-1.

Finally, monitoring module 200, when judging that the distribution power sum of described N number of energy-storage module is less than described target requirement power P obj, increases according to the current SOC of a described M battery pack energy-storage module that needs to carry out work from big to small.

According to another embodiment of the invention, when described target requirement power P obj is less than 0, the distribution power of each energy-storage module in monitoring module 200 N number of energy-storage module according to following formulae discovery:

Pk=Pobj*Sk（1-Sk）/｛Σ（1-Sk）｝（4）

Then, monitoring module 200 is when judging that the distribution power of a kth energy-storage module in described N number of energy-storage module is greater than himself charge power limit value, monitoring module judges that the distribution power of a described kth energy-storage module is as himself charge power limit value, and according to kth in a following formulae discovery N-1 energy-storage module ' the distribution power of individual energy-storage module:

Pk’=（Pobj-Pk）*Sk’（1-Sk）/｛Σ（1-Sk）-（1-Sk）｝（5）

Finally, monitoring module 200, when the absolute value of the distribution power sum judging described N number of energy-storage module is less than the absolute value of described target requirement power P obj, increases according to the current SOC of a described M battery pack energy-storage module that needs to carry out work from small to large.

In sum, the technical problem that the battery energy storage system for peak load shifting of the embodiment of the present invention solves is that under high-power condition, the parallel connection of multiple-variable flow device is carried out battery in the energy-storage system of peak load shifting peak-frequency regulation and caused the high present situation of holistic cost compared with short-range missile.Therefore, according to the battery energy storage system for peak load shifting of the embodiment of the present invention, M energy-storage module is adopted to compose in parallel, the energy-storage module structure of M parallel connection is identical, and monitoring module is according to charge-discharge power demand curve, treated with a certain discrimination when the current SOC of M battery pack and the power-efficient curve of each energy-storage module carry out on off control and power division to M energy-storage module, follow " how electricity is put more, few electricity fills soon, high damage is used less, low damage is multiplex " principle, ensure the harmony of each energy-storage module battery pack to greatest extent, increase the useful life of battery pack, reduce system cost, be conducive to promoting.Simultaneously, M energy-storage module is in parallel not only because the raising of power grade enhances peak load shifting ability, the stability and security performance that improve electrical network are played and comparatively significantly acts on, and due to M energy-storage module separate, less for the normal influence on system operation of system during single energy-storage module fault, improve redundancy and the applicability of system.

Fig. 2 is the flow chart of the control method of the battery energy storage system for peak load shifting according to the embodiment of the present invention.Wherein, battery energy storage system comprises M energy-storage module in parallel, and each energy-storage module comprises battery pack and two way convertor, and M be greater than 1 integer.As shown in Figure 2, this control method comprises the following steps:

S1, obtains the current SOC of charge-discharge power demand curve and M battery pack.

S2, carries out on off control and power division according to charge-discharge power demand curve, the current SOC of a M battery pack and the power-efficient curve of each energy-storage module to M energy-storage module.

In one embodiment of the invention, as shown in Figure 3, the control method of the above-mentioned battery energy storage system for peak load shifting comprises the following steps:

S301, obtains charge-discharge power demand curve.Wherein, charge-discharge power demand curve can be obtained according to the historical power data of monitoring and electric network data, or receive the charge-discharge power demand curve of host computer transmission.

S302, obtains the current SOC of M battery pack.Namely can according to total discharge and recharge time of M battery pack, actual heap(ed) capacity, nominal heap(ed) capacity and the information such as cell decay life characteristic obtained through great many of experiments, calculate the attenuation degree of battery and possible useful life, thus obtain the current SOC of M battery pack.

S303, limits target requirement power.Further, the total capacity of total SOC and M battery pack of M battery pack is obtained according to the current SOC of M battery pack; Whether target requirement power when judging that described battery energy storage system starts according to the total capacity of total SOC and M battery pack and charge-discharge power demand curve is more than or equal to system charge-discharge electric power limit value; If so, be then described target requirement power with described system charge-discharge electric power limit value.Namely say, battery energy storage system start time target requirement power be more than or equal to system discharge power limit, then with system discharge power limit for target requirement power; Battery energy storage system start time target requirement power be more than or equal to system charge power limit value, then with system charge power limit value for target requirement power.

S304, judges that target requirement power is the need of change.If so, return step S303, continue restriction; If not, step S305 is performed.

S305, rough calculation needs the quantity of the energy-storage module carrying out work, and adjusts needing to start the quantity of carrying out the energy-storage module of work according to the single charge-discharge electric power limit value of energy-storage module and target requirement power.

That is, calculate according to the rated power of described target requirement power and described each energy-storage module the quantity needing the energy-storage module carrying out work.

Wherein, the quantity of the energy-storage module carrying out work can be needed according to following formulae discovery:

N=rounds (︱ Pobj ︱/Pe)+1

Wherein, N is the described quantity needing the energy-storage module carrying out work, and Pobj is described target requirement power, and Pe is the rated power of described each energy-storage module.

S306, finally needs the quantity of the energy-storage module carrying out work according to the power-efficient curve calculation of each energy-storage module.

Namely say, according to the power-efficient curve of described each energy-storage module and the total losses of the N number of energy-storage module of described target requirement power calculation and the total losses of N+1 energy-storage module and/or the total losses of N-1 energy-storage module to adjust the described quantity N needing the energy-storage module carrying out work.

S307, carries out power division according to the current SOC of battery pack in each energy-storage module and the number of units of carrying out work.

Particularly, in one embodiment of the invention, as shown in Figure 4, in step S305, rated power according to target requirement power and each energy-storage module is just slightly determined to need to start the quantity of carrying out the energy-storage module of work, and adjust needing to start the quantity of carrying out the energy-storage module of work according to the single charge-discharge electric power limit value of energy-storage module and target requirement power, further comprising the steps:

S401, judges whether Pobj is greater than 0.If so, namely Pobj is greater than 0, performs step S402; If not, namely Pobj is less than 0, performs step S410.Wherein, it should be noted that, Pobj equals 0 and does not make a decision.

S402, the startup number of units N=calculating energy-storage module rounds (Pobj/Pe)+1.

S403, judges whether N >=M.If so, then step S404 is performed; If not, step S405 is performed.

S404，N=M。Namely saying, when needing the quantity N of the energy-storage module carrying out work to be more than or equal to M, judging that M energy-storage module is as the energy-storage module needing to carry out work.

S405, judges whether the number of units that single discharge power limit value is more than or equal to Pe is more than or equal to N.If so, step S406 is performed; If not, step S407 is performed.

S406, N=round (Pobj/Pe)+1.

That is, when target requirement power P obj be greater than 0 and described need the quantity N of the energy-storage module carrying out work to be less than M time, obtain the quantity that single discharge power limit value is greater than the energy-storage module of described rated power Pe; When the quantity that described single discharge power limit value is greater than the energy-storage module of described rated power Pe be more than or equal to described need the quantity N of the energy-storage module carrying out work time, control the described quantity N of the energy-storage module carrying out work that needs and remain unchanged.

S407, the current SOC according to battery pack chooses N=N+1 from big to small.

S408, judges whether Σ Plimitd >=Pobj.If so, step S409 is performed; If not, step S407 is returned.

S409，N=N。

That is, when the quantity that described single discharge power limit value is greater than the energy-storage module of described rated power Pe be less than described need the quantity N of the energy-storage module carrying out work time, the current SOC of a described M battery pack is sorted from big to small, and from M energy-storage module corresponding to M battery pack after sequence, chooses N+1 energy-storage module from big to small according to the current SOC of a described M battery pack; Then judge whether the single discharge power limit value sum of a described N+1 energy-storage module is more than or equal to described target requirement power P obj; If so, judge that a described N+1 energy-storage module is as the energy-storage module needing to carry out work; If not, from M energy-storage module corresponding to M battery pack after sequence, N+2 energy-storage module is chosen from big to small according to the current SOC of a described M battery pack, until the single discharge power limit value sum of N+i energy-storage module is more than or equal to described target requirement power P obj, wherein, i be more than or equal to 1 integer, and N+i is less than or equal to M.

In the present embodiment, if Pobj>0, the startup number of units N=calculating energy-storage module according to above-mentioned formula (1) rounds (Pobj/Pe)+1.Wherein, if N is more than or equal to the sum M of the energy-storage module of system, then N gets the sum M of the energy-storage module of system; If N is less than M, then judges that maximum discharge power and single discharge power limit value are greater than the number of units of the energy-storage module of Pe, if be more than or equal to N, then make N=N, namely need the quantity N of the energy-storage module carrying out work to remain unchanged; If the number of units that single discharge power limit value is greater than the energy-storage module of Pe is less than N, then according to the current SOC sequence of the battery pack in each energy-storage module, choose N=N+1 platform (if the current SOC of battery pack is identical, selecting the energy-storage module of the longer correspondence of the lower life expectancy of battery loss) from big to small, by the discharge power limit value sum of N+1 platform energy-storage module and target requirement power ratio comparatively, if Σ is Plimitd >=Pobj, N=N is made; Otherwise then make N=N+1, until Σ Plimitd >=Pobj sets up.

S410, N=round (︱ Pobj ︱/Pe)+1.

S411, judges whether N >=M.If so, then step S412 is performed; If not, step S413 is performed.

S412，N=M。Namely saying, when needing the quantity N of the energy-storage module carrying out work to be more than or equal to M, judging that M energy-storage module is as the energy-storage module needing to carry out work.

S413, judges whether the number of units that single charge power limit value is more than or equal to Pe is more than or equal to N.If so, step S414 is performed; If not, step S415 is performed.

S414, N=round (︱ Pobj ︱/Pe)+1.

That is, when described target requirement power P obj be less than 0 and described need the quantity N of the energy-storage module carrying out work to be less than M time, obtain the quantity that single charge power limit value is greater than the energy-storage module of described rated power Pe; When the quantity that described single charge power limit value is greater than the energy-storage module of described rated power Pe be more than or equal to described need the quantity N of the energy-storage module carrying out work time, control the described quantity N of the energy-storage module carrying out work that needs and remain unchanged.

S415, the current SOC according to battery pack chooses N=N+1 from small to large.

S416, judges whether Σ | Plimitd| >=| Pobj|.If so, step S417 is performed; If not, step S415 is returned.

S417，N=N。

That is, when the quantity that described single charge power limit value is greater than the energy-storage module of described rated power Pe be less than described need the quantity N of the energy-storage module carrying out work time, the current SOC of a described M battery pack is sorted from small to large, and from M energy-storage module corresponding to M battery pack after sequence, chooses N+1 energy-storage module from small to large according to the current SOC of a described M battery pack; Judge whether the absolute value of the single charge power limit value sum of a described N+1 energy-storage module is more than or equal to the absolute value of described target requirement power P obj; If so, judge that a described N+1 energy-storage module is as the energy-storage module needing to carry out work; If not, from M energy-storage module corresponding to M battery pack after sequence, N+2 energy-storage module is chosen from small to large according to the current SOC of a described M battery pack, until the absolute value of the single charge power limit value sum of N+j energy-storage module is more than or equal to the absolute value of described target requirement power P obj, wherein, j be more than or equal to 1 integer, and N+j is less than or equal to M.

Namely say, in the present embodiment, if Pobj<0, the startup number of units N=that monitoring module calculates energy-storage module according to above-mentioned formula (1) rounds (︱ Pobj ︱/Pe)+1.Wherein, if N is more than or equal to the sum M of the energy-storage module of system, then N gets the sum M of the energy-storage module of system; If N is less than M, then judges that maximum charge power and single charge power limit value are greater than the number of units of the energy-storage module of Pe, if be more than or equal to N, then make N=N, namely need the quantity N of the energy-storage module carrying out work to remain unchanged; If the number of units that single charge power limit value is greater than the energy-storage module of Pe is less than N, then according to the current SOC sequence of the battery pack in each energy-storage module, choose N=N+1 platform (if the current SOC of battery pack is identical, selecting the energy-storage module of the longer correspondence of the lower life expectancy of battery loss) from small to large, by the absolute value of the charge power limit value sum of N+1 platform energy-storage module and target requirement power ratio comparatively, if Σ | Plimitd| >=| Pobj|, makes N=N; Otherwise then make N=N+1, until Σ | Plimitd| >=| Pobj| sets up.

Particularly, in one embodiment of the invention, as shown in Figure 5, in step S307, power division is carried out according to the current SOC of battery pack in each energy-storage module and the number of units of carrying out work, further comprising the steps:

S501, when N number of energy-storage module carries out work, in each energy-storage module, the current SOC of battery pack is Sk, wherein, K=1,2,3 ..., N.

S502, calculates the current SOC sum of N number of battery pack and current (1-SOC) sum of N number of battery pack.

Namely say, when N number of energy-storage module carries out work, the current SOC sum calculating the N number of battery pack in N number of energy-storage module is Sum(SOC)=Σ Sk, and calculate current (1-SOC) sum Sum(1-SOC of the N number of battery pack in described N number of energy-storage module)=Σ (1-Sk), wherein, Sk is current SOC, the k=1,2,3 of a kth battery pack in described N number of battery pack ... N.

S503, judges whether Pobj is greater than 0.If so, namely Pobj is greater than 0, performs step S504; If not, namely Pobj is less than 0, performs step S509.Wherein, it should be noted that, Pobj equals 0 and does not make a decision.

S504, calculates the power P k=Pobj*Sk/(Σ Sk of a kth energy-storage module).That is, when described target requirement power P obj is greater than 0, the distribution power of each energy-storage module in N number of energy-storage module according to following formulae discovery:

Pk=Pobj*Sk/（ΣSk）

S505, judges that whether Pk is limited.If so, then step S506 is performed; If not, then step S504 is returned.

S506, calculates kth ' power P k '=(Pobj-Pk) * Sk '/(the Σ Sk-Sk) of individual energy-storage module.

That is, when judging that the distribution power of a kth energy-storage module in described N number of energy-storage module is greater than himself discharge power limit value, judge that the distribution power of a described kth energy-storage module is as himself discharge power limit value, and according to kth in a following formulae discovery N-1 energy-storage module ' the distribution power of individual energy-storage module:

Pk’=（Pobj-Pk）*Sk’/（ΣSk-Sk）

S507, judges whether Σ Pk is less than Pobj.If so, step S508 is performed; If not, step S505 is returned.

S508, restarts an energy-storage module according to SOC size, returns step S504.

That is, when judging that the distribution power sum of described N number of energy-storage module is less than described target requirement power P obj, increase according to the current SOC of a described M battery pack energy-storage module that needs to carry out work from big to small.

S509, calculates the power P k=Pobj*Sk(1-Sk of a kth energy-storage module)/{ Σ (1-Sk) }.Namely when described target requirement power P obj is less than 0, the distribution power of each energy-storage module in N number of energy-storage module according to following formulae discovery:

Pk=Pobj*Sk（1-Sk）/｛Σ（1-Sk）｝

S510, judges that whether Pk is limited.If so, then step S511 is performed; If not, then step S509 is returned.

S511, calculates power P k '=(Pobj-Pk) * Sk ' (1-Sk)/{ Σ (1-Sk)-(1-Sk) } of a kth energy-storage module.

That is, when judging that the distribution power of a kth energy-storage module in described N number of energy-storage module is greater than himself charge power limit value, judge that the distribution power of a described kth energy-storage module is as himself charge power limit value, and according to kth in a following formulae discovery N-1 energy-storage module ' the distribution power of individual energy-storage module:

Pk’=（Pobj-Pk）*Sk’（1-Sk）/｛Σ（1-Sk）-（1-Sk）｝

S512, Σ | whether Pk| is less than | Pobj|.If so, step S513 is performed; If not, step S510 is returned.

S513, restarts an energy-storage module according to SOC size, returns step S509.

That is, when the absolute value of the distribution power sum judging described N number of energy-storage module is less than the absolute value of described target requirement power P obj, increase according to the current SOC of a described M battery pack energy-storage module that needs to carry out work from small to large.

Describe and can be understood in flow chart or in this any process otherwise described or method, represent and comprise one or more for realizing the module of the code of the executable instruction of the step of specific logical function or process, fragment or part, and the scope of the preferred embodiment of the present invention comprises other realization, wherein can not according to order that is shown or that discuss, comprise according to involved function by the mode while of basic or by contrary order, carry out n-back test, this should understand by embodiments of the invention person of ordinary skill in the field.

In flow charts represent or in this logic otherwise described and/or step, such as, the sequencing list of the executable instruction for realizing logic function can be considered to, may be embodied in any computer-readable medium, for instruction execution system, device or equipment (as computer based system, comprise the system of processor or other can from instruction execution system, device or equipment instruction fetch and perform the system of instruction) use, or to use in conjunction with these instruction execution systems, device or equipment.With regard to this specification, " computer-readable medium " can be anyly can to comprise, store, communicate, propagate or transmission procedure for instruction execution system, device or equipment or the device that uses in conjunction with these instruction execution systems, device or equipment.The example more specifically (non-exhaustive list) of computer-readable medium comprises following: the electrical connection section (electronic installation) with one or more wiring, portable computer diskette box (magnetic device), random-access memory (ram), read-only memory (ROM), erasablely edit read-only memory (EPROM or flash memory), fiber device, and portable optic disk read-only memory (CDROM).In addition, computer-readable medium can be even paper or other suitable media that can print described program thereon, because can such as by carrying out optical scanner to paper or other media, then carry out editing, decipher or carry out process with other suitable methods if desired and electronically obtain described program, be then stored in computer storage.

Should be appreciated that each several part of the present invention can realize with hardware, software, firmware or their combination.In the above-described embodiment, multiple step or method can with to store in memory and the software performed by suitable instruction execution system or firmware realize.Such as, if realized with hardware, the same in another embodiment, can realize by any one in following technology well known in the art or their combination: the discrete logic with the logic gates for realizing logic function to data-signal, there is the application-specific integrated circuit (ASIC) of suitable combinational logic gate circuit, programmable gate array (PGA), field programmable gate array (FPGA) etc.

Those skilled in the art are appreciated that realizing all or part of step that above-described embodiment method carries is that the hardware that can carry out instruction relevant by program completes, described program can be stored in a kind of computer-readable recording medium, this program perform time, step comprising embodiment of the method one or a combination set of.

In addition, each functional unit in each embodiment of the present invention can be integrated in a processing module, also can be that the independent physics of unit exists, also can be integrated in a module by two or more unit.Above-mentioned integrated module both can adopt the form of hardware to realize, and the form of software function module also can be adopted to realize.If described integrated module using the form of software function module realize and as independently production marketing or use time, also can be stored in a computer read/write memory medium.

The above-mentioned storage medium mentioned can be read-only memory, disk or CD etc.

In the description of this specification, specific features, structure, material or feature that the description of reference term " embodiment ", " some embodiments ", " example ", " concrete example " or " some examples " etc. means to describe in conjunction with this embodiment or example are contained at least one embodiment of the present invention or example.In this manual, identical embodiment or example are not necessarily referred to the schematic representation of above-mentioned term.And the specific features of description, structure, material or feature can combine in an appropriate manner in any one or more embodiment or example.

Although illustrate and describe embodiments of the invention, for the ordinary skill in the art, be appreciated that and can carry out multiple change, amendment, replacement and modification to these embodiments without departing from the principles and spirit of the present invention, scope of the present invention is by claims and equivalency thereof.

Claims

1. for a battery energy storage system for peak load shifting, it is characterized in that, comprising:

M energy-storage module, a described M energy-storage module is parallel with one another, each energy-storage module in a described M energy-storage module comprises battery pack and two way convertor, the DC terminal of described two way convertor is connected with described battery pack, the interchange end of described two way convertor is connected with electrical network, wherein, M be greater than 1 integer;

Monitoring module, described monitoring module is connected with two way convertor respectively with the battery pack in described each energy-storage module, described monitoring module for obtaining the current SOC of charge-discharge power demand curve and M battery pack, and carries out on off control and power division according to the current SOC of described charge-discharge power demand curve, a described M battery pack and the power-efficient curve of described each energy-storage module to a described M energy-storage module.

2. as claimed in claim 1 for the battery energy storage system of peak load shifting, it is characterized in that, described monitoring module obtains total SOC of a described M battery pack according to the current SOC of a described M battery pack, and whether target requirement power when judging that described battery energy storage system starts according to described total SOC and described charge-discharge power demand curve is more than or equal to system charge-discharge electric power limit value, if so, be then described target requirement power with described system charge-discharge electric power limit value.

3. as claimed in claim 2 for the battery energy storage system of peak load shifting, it is characterized in that, described monitoring module calculates according to the rated power of described target requirement power and described each energy-storage module the quantity needing the energy-storage module carrying out work, wherein, described monitoring module needs the quantity of the energy-storage module carrying out work according to following formulae discovery:

N=rounds (︱ Pobj ︱/Pe)+1

4. as claimed in claim 3 for the battery energy storage system of peak load shifting, it is characterized in that, when described target requirement power P obj be greater than 0 and described need the quantity N of the energy-storage module carrying out work to be less than M time, described monitoring module obtains the quantity that single discharge power limit value is greater than the energy-storage module of described rated power Pe, wherein

When the quantity that described single discharge power limit value is greater than the energy-storage module of described rated power Pe be more than or equal to described need the quantity N of the energy-storage module carrying out work time, described monitoring module controls the described quantity N of the energy-storage module carrying out work that needs and remains unchanged;

When the quantity that described single discharge power limit value is greater than the energy-storage module of described rated power Pe be less than described need the quantity N of the energy-storage module carrying out work time, the current SOC of a described M battery pack sorts by described monitoring module from big to small, and from M energy-storage module corresponding to M battery pack after sequence, choose N+1 energy-storage module from big to small according to the current SOC of a described M battery pack, judge whether the single discharge power limit value sum of a described N+1 energy-storage module is more than or equal to described target requirement power P obj, wherein, if, described monitoring module judges that a described N+1 energy-storage module is as the energy-storage module needing to carry out work, if not, described monitoring module chooses N+2 energy-storage module from big to small according to the current SOC of a described M battery pack from M energy-storage module corresponding to M battery pack after sequence, until the single discharge power limit value sum of N+i energy-storage module is more than or equal to described target requirement power P obj, wherein, i be more than or equal to 1 integer, and N+i is less than or equal to M.

5. as claimed in claim 3 for the battery energy storage system of peak load shifting, it is characterized in that, when described target requirement power P obj be less than 0 and described need the quantity N of the energy-storage module carrying out work to be less than M time, described monitoring module obtains the quantity that single charge power limit value is greater than the energy-storage module of described rated power Pe, wherein

When the quantity that described single charge power limit value is greater than the energy-storage module of described rated power Pe be more than or equal to described need the quantity N of the energy-storage module carrying out work time, described monitoring module controls the described quantity N of the energy-storage module carrying out work that needs and remains unchanged;

When the quantity that described single charge power limit value is greater than the energy-storage module of described rated power Pe be less than described need the quantity N of the energy-storage module carrying out work time, the current SOC of a described M battery pack sorts by described monitoring module from small to large, and from M energy-storage module corresponding to M battery pack after sequence, choose N+1 energy-storage module from small to large according to the current SOC of a described M battery pack, judge whether the absolute value of the single charge power limit value sum of a described N+1 energy-storage module is more than or equal to the absolute value of described target requirement power P obj, wherein, if, described monitoring module judges that a described N+1 energy-storage module is as the energy-storage module needing to carry out work, if not, described monitoring module chooses N+2 energy-storage module from small to large according to the current SOC of a described M battery pack from M energy-storage module corresponding to M battery pack after sequence, until the absolute value of the single charge power limit value sum of N+j energy-storage module is more than or equal to the absolute value of described target requirement power P obj, wherein, j be more than or equal to 1 integer, and N+j is less than or equal to M.

6. as claimed in claim 3 for the battery energy storage system of peak load shifting, it is characterized in that, when N number of energy-storage module carries out work, the current SOC sum of N number of battery pack that described monitoring module calculates in described N number of energy-storage module is Sum(SOC)=Σ Sk, and calculate current (1-SOC) sum Sum(1-SOC of the N number of battery pack in described N number of energy-storage module)=Σ (1-Sk), wherein, Sk is current SOC, the k=1,2,3 of a kth battery pack in described N number of battery pack ... N.

7., as claimed in claim 6 for the battery energy storage system of peak load shifting, it is characterized in that, when described target requirement power P obj is greater than 0, the distribution power of each energy-storage module in described monitoring module N number of energy-storage module according to following formulae discovery:

Pk=Pobj*Sk/（ΣSk）

Wherein, Pk is the distribution power of a kth energy-storage module in described N number of energy-storage module;

And described monitoring module is when judging that the distribution power of a kth energy-storage module in described N number of energy-storage module is greater than himself discharge power limit value, described monitoring module judges that the distribution power of a described kth energy-storage module is as himself discharge power limit value, and according to kth in a following formulae discovery N-1 energy-storage module ' the distribution power of individual energy-storage module:

Pk’=（Pobj-Pk）*Sk’/（ΣSk-Sk）

8. as claimed in claim 7 for the battery energy storage system of peak load shifting, it is characterized in that, described monitoring module, when judging that the distribution power sum of described N number of energy-storage module is less than described target requirement power P obj, increases according to the current SOC of a described M battery pack energy-storage module that needs to carry out work from big to small.

9., as claimed in claim 6 for the battery energy storage system of peak load shifting, it is characterized in that, when described target requirement power P obj is less than 0, the distribution power of each energy-storage module in described monitoring module N number of energy-storage module according to following formulae discovery:

Pk=Pobj*Sk（1-Sk）/｛Σ（1-Sk）｝

And described monitoring module is when judging that the distribution power of a kth energy-storage module in described N number of energy-storage module is less than himself charge power limit value, described monitoring module judges that the distribution power of a described kth energy-storage module is as himself charge power limit value, and according to kth in a following formulae discovery N-1 energy-storage module ' the distribution power of individual energy-storage module:

Pk’=（Pobj-Pk）*Sk’（1-Sk）/｛Σ（1-Sk）-（1-Sk）｝

10. as claimed in claim 9 for the battery energy storage system of peak load shifting, it is characterized in that, described monitoring module, when the absolute value of the distribution power sum judging described N number of energy-storage module is less than the absolute value of described target requirement power P obj, increases according to the current SOC of a described M battery pack energy-storage module that needs to carry out work from small to large.

11. 1 kinds of control methods for the battery energy storage system of peak load shifting, it is characterized in that, described battery energy storage system comprises M energy-storage module in parallel, and each energy-storage module comprises battery pack and two way convertor, and M be greater than 1 integer, described control method comprises the following steps:

S1, obtains the current SOC of charge-discharge power demand curve and M battery pack;

S2, carries out on off control and power division according to the current SOC of described charge-discharge power demand curve, a described M battery pack and the power-efficient curve of described each energy-storage module to a described M energy-storage module.

12., as claimed in claim 11 for the control method of the battery energy storage system of peak load shifting, is characterized in that, in step s 2, also comprise:

Total SOC of a described M battery pack is obtained according to the current SOC of a described M battery pack;

Whether target requirement power when judging that described battery energy storage system starts according to described total SOC and described charge-discharge power demand curve is more than or equal to system charge-discharge electric power limit value;

If so, be then described target requirement power with described system charge-discharge electric power limit value.

13. as claimed in claim 12 for the control method of the battery energy storage system of peak load shifting, it is characterized in that, in step s 2, rated power according to described target requirement power and described each energy-storage module calculates the quantity needing the energy-storage module carrying out work, wherein, according to following formulae discovery, need the quantity of the energy-storage module carrying out work:

N=rounds (︱ Pobj ︱/Pe)+1

14., as claimed in claim 13 for the control method of the battery energy storage system of peak load shifting, is characterized in that,

When described target requirement power P obj be greater than 0 and described need the quantity N of the energy-storage module carrying out work to be less than M time, obtain the quantity that single discharge power limit value is greater than the energy-storage module of described rated power Pe, wherein,

When the quantity that described single discharge power limit value is greater than the energy-storage module of described rated power Pe be more than or equal to described need the quantity N of the energy-storage module carrying out work time, control the described quantity N of the energy-storage module carrying out work that needs and remain unchanged;

When the quantity that described single discharge power limit value is greater than the energy-storage module of described rated power Pe be less than described need the quantity N of the energy-storage module carrying out work time, the current SOC of a described M battery pack is sorted from big to small, and from M energy-storage module corresponding to M battery pack after sequence, choose N+1 energy-storage module from big to small according to the current SOC of a described M battery pack, judge whether the single discharge power limit value sum of a described N+1 energy-storage module is more than or equal to described target requirement power P obj; If so, judge that a described N+1 energy-storage module is as the energy-storage module needing to carry out work; If not, from M energy-storage module corresponding to M battery pack after sequence, N+2 energy-storage module is chosen from big to small according to the current SOC of a described M battery pack, until the single discharge power limit value sum of N+i energy-storage module is more than or equal to described target requirement power P obj, wherein, i be more than or equal to 1 integer, and N+i is less than or equal to M.

15., as claimed in claim 13 for the control method of the battery energy storage system of peak load shifting, is characterized in that,

When described target requirement power P obj be less than 0 and described need the quantity N of the energy-storage module carrying out work to be less than M time, obtain the quantity that single charge power limit value is greater than the energy-storage module of described rated power Pe, wherein,

When the quantity that described single charge power limit value is greater than the energy-storage module of described rated power Pe be more than or equal to described need the quantity N of the energy-storage module carrying out work time, control the described quantity N of the energy-storage module carrying out work that needs and remain unchanged;

When the quantity that described single charge power limit value is greater than the energy-storage module of described rated power Pe be less than described need the quantity N of the energy-storage module carrying out work time, the current SOC of a described M battery pack is sorted from small to large, and from M energy-storage module corresponding to M battery pack after sequence, choose N+1 energy-storage module from small to large according to the current SOC of a described M battery pack, judge whether the absolute value of the single charge power limit value sum of a described N+1 energy-storage module is more than or equal to the absolute value of described target requirement power P obj; If so, judge that a described N+1 energy-storage module is as the energy-storage module needing to carry out work; If not, from M energy-storage module corresponding to M battery pack after sequence, N+2 energy-storage module is chosen from small to large according to the current SOC of a described M battery pack, until the absolute value of the single charge power limit value sum of N+j energy-storage module is more than or equal to the absolute value of described target requirement power P obj, wherein, j be more than or equal to 1 integer, and N+j is less than or equal to M.

16. as claimed in claim 13 for the control method of the battery energy storage system of peak load shifting, it is characterized in that, when N number of energy-storage module carries out work, the current SOC sum calculating the N number of battery pack in described N number of energy-storage module is Sum(SOC)=Σ Sk, and calculate current (1-SOC) sum Sum(1-SOC of the N number of battery pack in described N number of energy-storage module)=Σ (1-Sk), wherein, Sk is current SOC, the k=1,2,3 of a kth battery pack in described N number of battery pack ... N.

17., as claimed in claim 16 for the control method of the battery energy storage system of peak load shifting, is characterized in that, when described target requirement power P obj is greater than 0, and the distribution power of each energy-storage module in N number of energy-storage module according to following formulae discovery:

Pk=Pobj*Sk/（ΣSk）

And when judging that the distribution power of a kth energy-storage module in described N number of energy-storage module is greater than himself discharge power limit value, judge that the distribution power of a described kth energy-storage module is as himself discharge power limit value, and according to kth in a following formulae discovery N-1 energy-storage module ' the distribution power of individual energy-storage module:

Pk’=（Pobj-Pk）*Sk’/（ΣSk-Sk）

18. as claimed in claim 17 for the control method of the battery energy storage system of peak load shifting, it is characterized in that, when judging that the distribution power sum of described N number of energy-storage module is less than described target requirement power P obj, increase according to the current SOC of a described M battery pack energy-storage module that needs to carry out work from big to small.

19., as claimed in claim 16 for the control method of the battery energy storage system of peak load shifting, is characterized in that, when described target requirement power P obj is less than 0, and the distribution power of each energy-storage module in N number of energy-storage module according to following formulae discovery:

Pk=Pobj*Sk（1-Sk）/｛Σ（1-Sk）｝

And when judging that the distribution power of a kth energy-storage module in described N number of energy-storage module is greater than himself charge power limit value, judge that the distribution power of a described kth energy-storage module is as himself charge power limit value, and according to kth in a following formulae discovery N-1 energy-storage module ' the distribution power of individual energy-storage module:

Pk’=（Pobj-Pk）*Sk’（1-Sk）/｛Σ（1-Sk）-（1-Sk）｝

20. as claimed in claim 19 for the control method of the battery energy storage system of peak load shifting, it is characterized in that, when the absolute value of the distribution power sum judging described N number of energy-storage module is less than the absolute value of described target requirement power P obj, increase according to the current SOC of a described M battery pack energy-storage module that needs to carry out work from small to large.