CN109904850A - The charge/discharge control method of energy-storage units in a kind of distributed energy storage direct-current grid - Google Patents
The charge/discharge control method of energy-storage units in a kind of distributed energy storage direct-current grid Download PDFInfo
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Abstract
The present invention relates to the charge/discharge control methods and system of energy-storage units in a kind of distributed energy storage direct-current grid, balance factor is introduced in governing equation, in discharge regime, the higher energy-storage units of SOC export higher discharge current, and the lower energy-storage units needs of SOC are released compared with low battery；In the charging stage, the charging current of the higher energy-storage units of SOC needs to maintain reduced levels, and the lower energy-storage units of SOC need to obtain biggish charging current, and the SOC of balanced different energy-storage units is achieved the purpose that with this.The present invention in original sagging coefficient by introducing the balance factor based on state-of-charge SOC, adjust the charge status of each energy-storage units constantly with its SOC value, achieve the purpose that the SOC of each energy-storage units of Fast-Balance, the fast uniform that each energy-storage units SOC may be implemented, improves the service life of energy-storage units.
Description
Technical field
The present invention relates to microdot net energy storage control technology fields, more particularly in a kind of distributed energy storage direct-current grid
The charge/discharge control method and system of energy-storage units.
Background technique
Currently, with environmental problem highlight and the enhancing of mankind's environmental consciousness, have cleaning, reproducibility, can be just
The renewable distributed generation resources such as photovoltaic, the blower of the advantages that ground dissolves are rapidly developed, and micro-capacitance sensor integrates multiclass new energy
As research hotspot.
By grid-connected converter, photovoltaic, blower distributed power supply in parallel can access DC grid, and due in micro-capacitance sensor
Most of distributed generation resources have the characteristics that fluctuation, intermittence and unstability, to realize connecing for large-scale distributed power supply
Enter and dissolve, in order to guarantee the stable operation of system, the energy-storage units such as battery, supercapacitor must be configured in micro-capacitance sensor.
And in order to realize the dilatation and system stability of micro-capacitance sensor, multiple distributed energy storage units can be usually configured in micro-capacitance sensor.
Since distributed energy storage cellular manufacture technique, charge status are different, lead to the initial of distributed energy storage unit
State-of-charge (state of charge, SOC) is not identical.In addition, due to the difference of micro-capacitance sensor line length and degree of aging,
The line impedance of micro-capacitance sensor is not generally identical.In the case where line impedance difference is different with initial state-of-charge, using tradition
When sagging control, each energy-storage units its SOC during charging and discharging can be in unbalanced state.Further, since energy storage
For unit there can be no overcharging or the state of over-discharge, the unbalanced of SOC is easy to cause part energy-storage units to log off operation, thus
The charge/discharge speed for accelerating remaining energy-storage units, is unfavorable for the service life of energy-storage system.
Summary of the invention
The present invention provides the charge/discharge control method and system of energy-storage units in a kind of distributed energy storage direct-current grid, uses
With solve present in existing droop control method because each energy-storage units state of charge it is unbalanced caused by the energy-storage units service life
Short problem.
The technical scheme to solve the above technical problems is that energy storage list in a kind of distributed energy storage direct-current grid
The charge/discharge control method of member, in discharge regime, the corresponding controller of p-th of energy-storage units controls its electric discharge, q-th of energy storage list
The corresponding controller of member controls its electric discharge, and works as SOCp> SOCqWhen, the corresponding controller of p-th of energy-storage units controls it
The discharge current of electric discharge is greater than the discharge current that the corresponding controller of q-th of energy-storage units controls its electric discharge；
In the charging stage, the corresponding controller of p-th of energy-storage units controls its charging, q-th of energy-storage units
Corresponding controller controls its charging, and works as SOCp> SOCqWhen, the corresponding controller of p-th of energy-storage units controls it and fills
The charging current of electricity is greater than the charging current that the corresponding controller of q-th of energy-storage units controls its charging；
Wherein, p and q is the number of any two energy-storage units in the distributed energy storage direct-current grid, SOCpFor institute
State the state of charge of p-th of energy-storage units, SOCqFor the state of charge of q-th of energy-storage units.
The beneficial effects of the present invention are: the higher energy-storage units of SOC must export higher electric discharge electricity in discharge regime
Stream, the lower energy-storage units needs of SOC are released compared with low battery；In the charging stage, the charging current of the higher energy-storage units of SOC
Need to maintain reduced levels, the lower energy-storage units of SOC need to obtain biggish charging current, reach balanced different storages with this
The purpose of the SOC of energy unit.Due to not being related to SOC in the sagging control strategy of tradition, control method of the invention enables to control
It makes the electric current exported to change with the SOC of energy-storage units and change, it is quickly accurate equal to guarantee that the SOC of energy-storage units is realized
Weighing apparatus.
Based on the above technical solution, the present invention can also be improved as follows.
Further, the corresponding controller of each energy-storage units executes governing equation based on control are as follows: udcj=
udcref-Kj·idcj·Gj；
In formula, j indicates the number of any energy-storage units in the distributed energy storage direct-current grid, udcjIndicate j-th of storage
The output voltage of the corresponding controller of energy unit, udcrefIndicate preset voltage reference value, KjIndicate that j-th of energy-storage units is corresponding
Sagging coefficient, idcjIndicate the output electric current of the corresponding controller of j-th of energy-storage units, GjIndicate that j-th of energy-storage units is corresponding
Balance factor, be j-th of energy-storage units state of charge function.
Further beneficial effect of the invention is: by introducing in original sagging coefficient based on state-of-charge SOC
Balance factor adjusts the charge status of each energy-storage units constantly with its state of charge SOC, reaches each energy storage of Fast-Balance
The purpose of the SOC of unit may be implemented the fast uniform of each energy-storage units SOC, improve the service life of energy-storage units.
Further, the balance factorIn formula, n indicates the lotus of j-th of energy-storage units
The power exponent of electricity condition value SOC, value are positive number, R indicate it is preset be greater than 1 any positive number, idcj> 0 indicates discharge regime,
idcj< 0 indicates the charging stage.
Further beneficial effect of the invention is: since balance factor is the power function of state of charge SOC, for SOC
Resolution ratio with higher.When SOC reaches equilibrium state, balance factor size is identical, can guarantee the defeated of each energy-storage units
Electric current is identical out, and SOC state keeps synchronizing.Simultaneously as balance factor constantly changes with the state of SOC, keeping
In the case where the equilibrium of supply and demand, it can guarantee that line voltage distribution maintains to stablize to a certain extent.
Further, the value of the n is any positive integer less than 10.
Further beneficial effect of the invention is: since the power output size of energy-storage units is with balance factor correlation, passing through tune
The size of whole n can be suitable for the size for adjusting balance factor, to achieve the purpose that the balancing speed for adjusting energy-storage units.N takes
Value is the load condition limiting value that can be very good balance energy-storage units less than 10 and the relationship of balancing speed.
Further, the governing equation are as follows: udcj=udcref-Kj·idcj·Gj+rj·idcj, wherein rjIndicate j-th of storage
It can the corresponding line impedance of unit.
Further beneficial effect of the invention is: by analyzing based on line impedance SOC balance effect, establishing line
Roadlock is anti-to have great influence to SOC balance effect, by considering that the adaptive droop control method of line impedance can evade
The influence of line impedance realizes that the SOC high-precision of different energy-storage units is balanced, to solve the corresponding line impedance of each energy-storage units
The undesirable problem of SOC balance effect caused by having differences.
The present invention also provides a kind of charge-discharge control systems of energy-storage units in distributed energy storage direct-current grid, comprising:
The corresponding controller of all energy-storage units in the distributed energy storage direct-current grid；
In discharge regime, the corresponding controller of p-th of energy-storage units controls its electric discharge, and q-th of energy-storage units is corresponding
The controller control its electric discharge, and work as SOCp> SOCqWhen, the corresponding controller control of p-th of energy-storage units
Its discharge current to discharge is greater than the discharge current that the corresponding controller of q-th of energy-storage units controls its electric discharge；
In the charging stage, the corresponding controller of p-th of energy-storage units controls its charging, q-th of energy storage
The corresponding controller of unit controls its charging, and works as SOCp> SOCqWhen, the corresponding control of p-th of energy-storage units
The charging current that device processed controls its charging is greater than the charging that the corresponding controller of q-th of energy-storage units controls its charging
Electric current；
Wherein, p and q is the number of any two energy-storage units in the distributed energy storage direct-current grid, SOCpFor institute
State the state of charge of p-th of energy-storage units, SOCqFor the state of charge of q-th of energy-storage units.
The beneficial effects of the present invention are: the higher energy-storage units of SOC must export higher electric discharge electricity in discharge regime
Stream, the lower energy-storage units needs of SOC are released compared with low battery；In the charging stage, the charging current of the higher energy-storage units of SOC
Need to maintain reduced levels, the lower energy-storage units of SOC need to obtain biggish charging current, reach balanced different storages with this
The purpose of the SOC of energy unit.Due to not being related to SOC in the sagging control strategy of tradition, present invention introduces controller enable to
Its electric current for controlling output changes with the SOC of energy-storage units and is changed, and it is quickly accurate to guarantee that the SOC of energy-storage units is realized
It is balanced.
Further, the corresponding controller of each energy-storage units executes governing equation based on control are as follows: udcj
=udcref-Kj·idcj·Gj, in formula, j indicates the number of any energy-storage units in the distributed energy storage direct-current grid, udcj
Indicate the output voltage of the corresponding controller of j-th of energy-storage units, udcrefIndicate preset voltage reference value, KjIndicate the
The corresponding sagging coefficient of j energy-storage units, idcjIndicate the output electric current of the corresponding controller of j-th of energy-storage units, GjTable
Show the corresponding balance factor of j-th of energy-storage units, is the function of the state of charge of j-th of energy-storage units.
Further beneficial effect of the invention is: by introducing in original sagging coefficient based on state-of-charge SOC
Balance factor adjusts the charge status of each energy-storage units constantly with its state of charge SOC, reaches each energy storage of Fast-Balance
The purpose of the SOC of unit may be implemented the fast uniform of each energy-storage units SOC, improve the service life of energy-storage units.
Further, the balance factorIn formula, n indicates j-th of energy-storage units
State of charge SOCjPower exponent, value is positive number, R indicate it is preset be greater than 1 any positive number, idcj> 0 indicates electric discharge rank
Section, idcj< 0 indicates the charging stage.
Further beneficial effect of the invention is: since balance factor is the power function of state of charge SOC, for SOC
Resolution ratio with higher.When SOC reaches equilibrium state, balance factor size is identical, can guarantee the defeated of each energy-storage units
Electric current is identical out, and SOC state keeps synchronizing.Simultaneously as balance factor constantly changes with the state of SOC, keeping
In the case where the equilibrium of supply and demand, it can guarantee that line voltage distribution maintains to stablize to a certain extent.
Further, the value of the n is any positive integer less than 10.
Further beneficial effect of the invention is: since the power output size of energy-storage units is with balance factor correlation, passing through tune
The size of whole n can be suitable for the size for adjusting balance factor, to achieve the purpose that the balancing speed for adjusting energy-storage units.N takes
Value is the load condition limiting value that can be very good balance energy-storage units less than 10 and the relationship of balancing speed.
Further, the governing equation are as follows: udcj=udcref-Kj·idcj·Gj+rj·idcj, wherein rjIndicate j-th of storage
It can the corresponding line impedance of unit.
Further beneficial effect of the invention is: by analyzing based on line impedance SOC balance effect, establishing line
Roadlock is anti-to have great influence to SOC balance effect, and controller of the invention can evade route resistance by considering line impedance
The SOC high-precision Balance route of different energy-storage units is realized in anti-influence, is deposited with solving the corresponding line impedance of each energy-storage units
The undesirable problem of SOC balance effect caused by difference.
Detailed description of the invention
Fig. 1 is a kind of structure chart of distributed energy storage direct-current grid provided by one embodiment of the present invention；
Fig. 2 is the equivalent circuit diagram based on Fig. 1 that another embodiment of the present invention provides；
The charge and discharge of energy-storage units in a kind of distributed energy storage direct-current grid that Fig. 3 provides for another embodiment of the present invention
The control characteristic schematic diagram of electric control method；
Fig. 4 (a) is the micro-capacitance sensor SOC balance figure that another embodiment of the present invention provides；
Fig. 4 (b) is the micro-capacitance sensor SOC balance figure that another embodiment of the present invention provides；
Fig. 5 (a) is SOC balance figure when the micro-capacitance sensor that another embodiment of the present invention provides disturbs；
Fig. 5 (b) is SOC balance figure when the micro-capacitance sensor micro-capacitance sensor that another embodiment of the present invention provides disturbs；
Fig. 6 (a) is the control method that another embodiment of the present invention provides and existing control method in terms of SOC balance
Difference schematic diagram；
Fig. 6 (b) is the control method that another embodiment of the present invention provides and existing control method in terms of SOC balance
Difference schematic diagram.
Specific embodiment
The principle and features of the present invention will be described below with reference to the accompanying drawings, and the given examples are served only to explain the present invention, and
It is non-to be used to limit the scope of the invention.
Embodiment one
The charge/discharge control method of energy-storage units in a kind of distributed energy storage direct-current grid, in discharge regime, p-th of storage
The corresponding controller of energy unit controls its electric discharge, and the corresponding controller of q-th of energy-storage units controls its electric discharge, and works as SOCp>
SOCqWhen, the discharge current that the corresponding controller of p-th of energy-storage units controls its electric discharge is greater than the corresponding control of q-th of energy-storage units
Device processed controls the discharge current of its electric discharge；In the charging stage, the corresponding controller of p-th of energy-storage units controls its charging, and q-th
The corresponding controller of energy-storage units controls its charging, and works as SOCp> SOCqWhen, the corresponding controller control of p-th of energy-storage units
Its charging current to charge is greater than the charging current that the corresponding controller of q-th of energy-storage units controls its charging；Wherein, p and q are
The number of any two energy-storage units, SOC in distributed energy storage direct-current gridpFor the charged shape of p-th of energy-storage units
State value, SOCqFor the state of charge of q-th of energy-storage units.
In discharge regime, the higher energy-storage units of SOC must export higher discharge current, the lower energy-storage units of SOC
It needs to release compared with low battery；In the charging stage, the charging current of the higher energy-storage units of SOC needs to maintain reduced levels,
The lower energy-storage units of SOC need to obtain biggish charging current, and the SOC of balanced different energy-storage units is achieved the purpose that with this.
Due to not being related to SOC in the sagging control strategy of tradition, the electric current that control method of the invention enables to control to export is with energy storage
The SOC of unit changes and changes, and it is quickly accurate balanced to guarantee that the SOC of energy-storage units is realized.
Preferably, it is u that the corresponding controller of each energy-storage units, which executes governing equation based on control,dcj=udcref-
Kj·idcj·Gj, in formula, j indicates the number of any energy-storage units in distributed energy storage direct-current grid, udcjIndicate j-th of storage
The output voltage of the corresponding controller of energy unit, udcrefIndicate preset voltage reference value, KjIndicate that j-th of energy-storage units is corresponding
Sagging coefficient, idcjIndicate the output electric current of the corresponding controller of j-th of energy-storage units, GjIndicate that j-th of energy-storage units is corresponding
Balance factor, be j-th of energy-storage units state of charge function.
Governing equation enables to distributed energy storage direct-current grid, in the discharge current of each energy-storage units of discharge regime
It is in inverse ratio with its state of charge, it is proportional in the charging current of charging stage each energy-storage units and its state of charge.
It should be noted that control process is it is understood that the much voltage of load needs, is certain, control process reality
It is the output electric current of control.Existing method, governing equation udcj=udcref-Kj·idcj, udcjIndicate j-th of energy-storage units pair
The output voltage for the controller answered, KjIndicate the corresponding sagging coefficient of j-th of energy-storage units, idcjIndicate j-th of energy-storage units pair
The output electric current for the controller answered, each energy-storage units, under any load condition, output voltage is determined, and sagging coefficient is
Constant, then output electric current determines, and in the present embodiment, under any load condition, output voltage is equally determined, sagging system
Number is the function of state of charge SOC, i.e. SOC determines output electric current.
Droop control method after introducing balance factor realizes the SOC balance of distributed energy storage system.In electric discharge rank
Section, the higher energy-storage units of SOC must export higher discharge current, and the lower energy-storage units of SOC need to release lower electricity
Amount；In the charging stage, the charging current of the higher energy-storage units of SOC needs to maintain reduced levels, the lower energy-storage units of SOC
It needs to obtain biggish charging current, the SOC of balanced different energy-storage units is achieved the purpose that with this.
The present embodiment makes each energy storage by introducing the balance factor based on state-of-charge SOC in original sagging coefficient
The charge status of unit is constantly adjusted with its state of charge SOC, achievees the purpose that the SOC of each energy-storage units of Fast-Balance,
The fast uniform that each energy-storage units SOC may be implemented, improves the service life of energy-storage units.
Preferably, governing equation are as follows:In formula, j indicates distributed energy storage DC micro-electric
The number of any energy-storage units, G in netjIndicate that the corresponding balance factor of j-th of energy-storage units, n indicate j-th of energy-storage units
The power exponent of state-of-charge SOC, value are positive number, R indicate it is preset be greater than 1 any positive number, udcrefIndicate preset each
The voltage reference value of the corresponding controller of energy-storage units, udcjIndicate the output voltage of the corresponding controller of j-th of energy-storage units,
KjIndicate the corresponding sagging coefficient of j-th of energy-storage units, idcjIndicate the output electric current of the corresponding controller of j-th of energy-storage units,
Wherein, idcj> 0 indicates discharge regime, idcj< 0 indicates the charging stage.
For example, as shown in Figure 1, distributed energy storage system obtains DC output voltage u through DC/DC converterdcj, pass through
Impedance is rjLine impedance be connected to public network, give common load power supply.In order to extend the service life of energy-storage system, store up
Can the SOC of system preferably must be held in certain range (20%-80%), there can be no overcharging or over-discharge phenomenon, otherwise influence
The service life of energy-storage system.
It should be noted that when being controlled using existing droop control method the charge and discharge of energy-storage units, control
Equation processed can be indicated with following formula: udcj=udcref-Kj·idcj, each symbol meaning is same as above in formula, and details are not described herein.
The voltage u of public electric wire netpcc=udcj-rj·idcj, in formula, upccFor the DC voltage of public electric wire net, rjIt is j-th
The line impedance of route where energy-storage units.By above-mentioned udcjAnd upccKnown to expression formula:In formula, p, q are the citings of j, represent the number of any two energy-storage units, Qi Tabiao
Know meaning shown in according with to be same as above.
Under actual operating condition, it is assumed that the reference voltage of the corresponding controller of two energy-storage units is identical, and two are not
With the relationship of the output electric current of energy-storage units, can indicate are as follows:By formula it is found that not
Route not only related to sagging coefficient with the output electric current of energy-storage units reality output, also with route where each energy-storage units
Impedance is related.
And in energy-storage units, real surplus state-of-charge (state of charge, SOC) meter more difficult to estimate, but energy storage list
The calculation formula of the SOC of member are as follows:In formula, SOCjtIt is expressed as j-th of energy storage of t moment
The remaining state-of-charge (SOC) of unit, SOCj0It is expressed as the remaining state-of-charge (SOC) of j-th of energy-storage units of initial time, Cj
For the capacity of energy-storage units, ijbatOutput electric current when for j-th of energy-storage units without controller.
And in actual energy-storage system operational process, for convenience of calculating, often ignore loss (the i.e. route resistance of route
It is anti-) and DC/DC converter energy loss, formula can be obtained:
In formula, PjFor the active power that j-th of energy-storage units exports common load,
PjbatFor the active power of j-th of energy-storage units output, ujbatIt is the output voltage of j-th of energy-storage units, subscript bat represents storage
Can unit without controller institute reality output voltage, electric current or active power.
The remaining state-of-charge of available energy-storage system changes with time the parameters such as rate and energy-storage system output power
Relationship: the remaining state-of-charge change rate of energy storage is proportional to output electric current.It therefore, can only to the difference of balance energy storage SOC
By adjusting the output electric current of energy-storage units, and the micro-capacitance sensor structure of traditional droop control method is used, since sagging coefficient is solid
It is fixed constant, therefore do not have the function of balance SOC difference.
Therefore, the balance factor based on SOC state is introduced in original sagging coefficient, can reach the purpose of balance SOC,
Governing equation are as follows:As shown in the formula, GjFor the SOC introduced to j-th of energy-storage units
Balance factor.
In energy-storage units discharge regime, SOC bigger energy-storage units G value is smaller, and the value of discharge current is bigger at this time, SOC
Fall off rate is very fast；Conversely, SOC smaller energy-storage units discharge rate is slower, SOC fall off rate is slower.Similarly, in charging rank
Section, SOC bigger energy-storage units G value is bigger, and charging current is smaller at this time, and the rate that SOC rises is slower；Conversely, SOC is smaller
Energy-storage units charge rate is faster, and SOC climbing speed is faster.
To sum up, it is putting a little and is charging two stages, the control method that the present embodiment proposes can realize the balance of SOC.
Further, since G is the power function of SOC, resolution ratio with higher for SOC.When SOC reaches equilibrium state,
Balance factor G size is identical, can guarantee that the electric current of energy-storage units output is identical, SOC state keeps synchronizing；Simultaneously as G value
As the state of SOC constantly changes, in the case where keeping the equilibrium of supply and demand, it can guarantee line voltage distribution to a certain extent
It maintains to stablize.
Preferably, the value of n is any positive integer less than 10.
It can be suitable for adjusting equilibrium by adjusting the size of n since the power output size of energy-storage units is with balance factor correlation
The size of the factor, to achieve the purpose that the balancing speed for adjusting energy-storage units.N value is that can be very good to balance less than 10
The load condition limiting value of energy-storage units and the relationship of balancing speed.
Embodiment two
On the basis of example 1, governing equation are as follows: udcj=udcref-Kj·idcj·Gj+rj·idcj, wherein rjTable
Show the corresponding line impedance of j-th of energy-storage units.
For example, the electric system in Fig. 1 obtains Fig. 2 by simplification, as shown in Fig. 2, n voltage is udcrefPower supply pass through
Resistance is mj(SOC) and rjImpedance it is parallel with one another, while to impedance be RloadResistance power supply, upccFor common point voltage, idcj
Passing through resistance for j-th of energy-storage units is mj(SOC) resistance and the output electric current exported, available by circuit relationships:
Subscript j represents the correlated variables of j-th of energy-storage units, such as idcjRepresent the output electric current of j-th of energy-storage units, Rs
It is parallel impedance, n indicates the total number of energy-storage units in distributed energy storage direct-current grid, it should be noted that each energy storage
The reference voltage u of the corresponding controller of unitdcrefIt is equal.
After introducing the SOC balance factor, sagging coefficient substantially becomes Kj·Gj, it is denoted as mj(SOC), under indicating improved
Hang down coefficient.The electric current i of each energy-storage units output at this timedcjRelationship between SOC can determine output current difference Δ idc
With the relationship between charge state difference Δ SOC are as follows:
Δ i in formuladcpqThe output current difference for indicating p-th of energy-storage units and q-th of energy-storage units, can be seen by above formula
Out, the SOC balance of the system is the result is that the output electric current of energy-storage units is identical, i.e. Δ idcpqEqual to 0, m at this timeq(SOC)-mp
(SOC)=rp-rqIf difference is not present in line impedance, since output electric current is identical, the SOC of energy-storage units keeps identical；Such as
Fruit line impedance has differences, and since output current difference is reduced to zero, can not achieve the fully equalize of SOC.The difference of SOC is same
Line impedance parameter is related, and impedance parameter difference is bigger, and the portfolio effect of energy storage SOC is poorer；Otherwise effect is better.
In Fig. 3, for energy storage list that power independently distributes is realized in direct-current grid using traditional droop control method
For member, the mismatch of line impedance parameter causes the decline of power distribution precision.In Fig. 3, horizontal axis indicates each energy storage list
Size of current of the member Jing Guo two resistance reality outputs, the longitudinal axis indicate each energy-storage units reality output after two resistance
DC voltage.Solid line Lp(Lq) indicate the sagging controlling curve of tradition, QpAnd QqEach energy storage list when indicating using traditional sagging control
Member relationship of the DC voltage and electric current of reality output after two resistance is led since line impedance is unsatisfactory for matching condition
Cause curve QpAnd QqIt is inconsistent, i.e., as shown, idc1And idc2Difference, so that the actual output electric current of two energy-storage units exists
Difference, and then lead to the reduction of electric current assignment accuracy.
For this purpose, the present embodiment proposes adaptive sagging power distribution method, as shown in figure 3, in the feelings of power distribution unevenness
Under condition, by sagging controlling curve Lp(Lq) adaptively it is changed into L 'pWith L 'q.At this point, energy-storage units actual output voltage and output
The relationship of electric current is by QpAnd QqIt is changed into Q'1And Q'2, then the practical size of current provided of each energy-storage units becomes i 'dcpWith
i′dcq, therefore, the difference △ i of electric current distribution is eliminated, to realize the autonomous distribution and energy storage of direct-current grid power
The plug-and-play feature of unit.
For the sagging control of adaptive impovement for realizing microgrid, the sagging control expression formula of tradition should be modified are as follows: isolated to realize
The sagging control of the adaptive impovement of direct-current micro-grid, " current-voltage " sagging control expression formula in the sagging control of tradition should be modified
Are as follows:
udcj=udcrefj-mj(SOC)·idcj+hj·idcj
In formula, hjFor adaptive virtual resistance, the change to original sagging controlling curve is indicated.It can be concluded that under adaptive
The electric current relative different that two energy-storage units of control that hang down export are as follows:
When energy-storage units realize that electric current accurately distributes, above formula should be 0, for this purpose, adaptive virtual resistance hi(j=1,
2 ..., n) following relationship should be met:
hj=rj
In view of in systems in practice, line impedance rjIt can not accurately obtain, the present embodiment is in the local of each energy-storage units
The voltage u of direct current common bus is introduced in controlpccInstead of line resistance value, upccAnd rjTransformational relation can be by formula upcc=
udcj-rj·idcjIt obtains, therefore can obtain:
udcj=udcrefj-mj(SOC)·idcj+(udci-upcc)
The u obtained by above formuladcjThe control reference value of DC/DC converter voltage ring in as each energy-storage unitsThen pass through the bicyclic PI (Proportional- of voltage and current
Integral it) controls, the control signal of DC/DC converter can be obtained.
To sum up, the sagging control of tradition is optimized forMicro-capacitance sensor function can be improved
The precision of rate distribution.By it is female need to only share direct current in microgrid it is found that proposed in this paper improve sagging control as local distributing
Line voltage information reduces the requirement to communication system, ensure that the plug and play of system reliability of operation and energy-storage units
Function.
For example, being based on structure shown in FIG. 1, wherein DC bus-bar voltage upccBe set as 480V, two energy-storage units it is defeated
Voltage capacity u outdcFor 5Ah, line impedance r1And r2Respectively 3 Ω and 1.3 Ω load as 5kW, are used herein as the resistance of 50 Ω
Instead of Rload；Carry out simulating, verifying.
In Fig. 4 (a) and 4 (b), two energy-storage units residue state-of-charge initial value SOC1 and SOC2 are respectively set as fullcharging
The 80% of electricity condition and 70%.Shown in simulation result such as Fig. 4 (a), initial time No.1 energy-storage units output electric current is significantly greater than
No. two energy-storage units, SOC fall off rate are very fast；By 500s or so time, the residual charge capacity of energy-storage units is kept substantially
Unanimously, the SOC difference decline 0 of energy-storage units, and maintain to continue to discharge.Output voltage such as Fig. 4 (b) institute of energy-storage units simultaneously
Show, in SOC discharge process, the size of Vdc1 and Vdc2 are maintained at 475V or so, and the stability that can satisfy islanded system needs
It asks；Further, since the state-of-charge of energy-storage units continues to decline, the size of voltage is slightly reduced.
In Fig. 5 (a) and 5 (b), stability analysis is proposed as a result, this example is drawn on the basis of Fig. 4 (a) and 4 (b) by verifying
Enter load disturbance, a size is put into 50s by the load (replacing with the resistance of 50 Ω) of 5kW, Fig. 5 (a) and 5 (b) is imitative
True result.As shown, SOC difference value is declined before 50s with certain rate, voltage value keeps stablizing；Load investment with
Afterwards, since output electric current increases, the balancing speed of SOC increases, but still can be seen that stabilization from figure, and output electric current is increased
Add, but the size for exporting electric current still keeps stable.Further, since the increase of load, causes DC bus-bar voltage to be declined
(Voltage Drop of 20V or so), but stability can still be maintained in voltage.Thus, it is possible to obtain: more acute in load fluctuation
In the case where strong, the present embodiment control method still has the function of balance SOC, and is able to maintain the stability of system.
Fig. 6 (a) and 6 (b) is that the SOC before introducing the adaptive droop control method of the present embodiment and after introducing becomes respectively
Change process.It can be seen from the figure that the SOC value of energy-storage units is persistently reduced from 0.1 before introducing adaptive sagging control,
Since line impedance has differences, the output current difference of energy-storage units is still had at this time, and SOC difference value is caused persistently to be deposited
It cannot finally obtain completely equal as a result, and by it is found that line impedance difference is bigger, the result of SOC balance is more not above
It is ideal；And the SOC difference of energy-storage units goes to zero after introducing adaptive sagging control, is finally able to maintain identical speed
Electric discharge, can be realized ideal portfolio effect.
The present embodiment is established line impedance and imitated to SOC balance by being analyzed based on line impedance SOC balance effect
Fruit has great influence, real by considering that the adaptive droop control method of line impedance can evade the influence of line impedance
The SOC high-precision of existing different energy-storage units is balanced, to solve caused by the corresponding line impedance of each energy-storage units has differences
The undesirable problem of SOC balance effect.
Embodiment three
The charge-discharge control system of energy-storage units in a kind of distributed energy storage direct-current grid, comprising: distributed energy storage is straight
Flow the corresponding controller of all energy-storage units in micro-capacitance sensor；In discharge regime, the corresponding controller control of p-th of energy-storage units
Its electric discharge is made, the corresponding controller of q-th of energy-storage units controls its electric discharge, and works as SOCp> SOCqWhen, p-th of energy-storage units pair
The discharge current that the controller answered controls its electric discharge is greater than the corresponding controller of q-th of energy-storage units and controls putting for its electric discharge
Electric current；In the charging stage, the corresponding controller of p-th of energy-storage units controls its charging, and q-th of energy-storage units is corresponding
Controller controls its charging, and works as SOCp> SOCqWhen, the corresponding controller of p-th of energy-storage units controls the charging electricity of its charging
Stream is greater than the charging current that the corresponding controller of q-th of energy-storage units controls its charging；Wherein, p and q is distributed energy storage direct current
The number of any two energy-storage units, SOC in micro-capacitance sensorpFor the state of charge of p-th of energy-storage units, SOCqFor q-th of energy storage
The state of charge of unit.
In discharge regime, the higher energy-storage units of SOC must export higher discharge current, the lower energy-storage units of SOC
It needs to release compared with low battery；In the charging stage, the charging current of the higher energy-storage units of SOC needs to maintain reduced levels,
The lower energy-storage units of SOC need to obtain biggish charging current, and the SOC of balanced different energy-storage units is achieved the purpose that with this.
Due to not being related to SOC in the sagging control strategy of tradition, present invention introduces controller enable to the electric current of its control output with
The SOC of energy-storage units changes and changes, and it is quickly accurate balanced to guarantee that the SOC of energy-storage units is realized.
About governing equation based on the corresponding controller executive control operation of each energy-storage units with real-time one He of example
Embodiment two, details are not described herein.
The foregoing is merely presently preferred embodiments of the present invention, is not intended to limit the invention, it is all in spirit of the invention and
Within principle, any modification, equivalent replacement, improvement and so on be should all be included in the protection scope of the present invention.
Claims (10)
1. the charge/discharge control method of energy-storage units in a kind of distributed energy storage direct-current grid, which is characterized in that in electric discharge rank
Section, the corresponding controller of p-th of energy-storage units control its electric discharge, and the corresponding controller of q-th of energy-storage units controls its electric discharge, and
Work as SOCp> SOCqWhen, the discharge current that the corresponding controller of p-th of energy-storage units controls its electric discharge is greater than described q-th
The corresponding controller of energy-storage units controls the discharge current of its electric discharge；
In the charging stage, the corresponding controller of p-th of energy-storage units controls its charging, and q-th of energy-storage units are corresponding
Controller control its charging, and work as SOCp> SOCqWhen, the corresponding controller of p-th of energy-storage units controls its charging
Charging current is greater than the charging current that the corresponding controller of q-th of energy-storage units controls its charging；
Wherein, p and q is the number of any two energy-storage units in the distributed energy storage direct-current grid, SOCpFor the pth
The state of charge of a energy-storage units, SOCqFor the state of charge of q-th of energy-storage units.
2. the charge/discharge control method of energy-storage units in a kind of distributed energy storage direct-current grid according to claim 1,
It is characterized in that, the corresponding controller of each energy-storage units executes governing equation based on control are as follows: udcj=udcref-
Kj·idcj·Gj；
In formula, j indicates the number of any energy-storage units in the distributed energy storage direct-current grid, udcjIndicate j-th of energy storage list
The output voltage of the corresponding controller of member, udcrefIndicate preset voltage reference value, KjUnder indicating that j-th of energy-storage units is corresponding
Hang down coefficient, idcjIndicate the output electric current of the corresponding controller of j-th of energy-storage units, GjIndicate that j-th of energy-storage units is corresponding
Weigh the factor, is the function of the state of charge of j-th of energy-storage units.
3. the charge/discharge control method of energy-storage units in a kind of distributed energy storage direct-current grid according to claim 2,
It is characterized in that, the balance factorIn formula, n indicates the charged of j-th of energy-storage units
State value SOCjPower exponent, value is positive number, R indicate it is preset be greater than 1 any positive number, idcj> 0 indicates discharge regime,
idcj< 0 indicates the charging stage.
4. the charge/discharge control method of energy-storage units in a kind of distributed energy storage direct-current grid according to claim 3,
It is characterized in that, the value of the n is any positive integer less than 10.
5. the charge and discharge of energy-storage units in a kind of distributed energy storage direct-current grid according to any one of claims 1 to 4
Control method, which is characterized in that the governing equation are as follows: udcj=udcref-Kj·idcj·Gj+rj·idcj, wherein rjIndicate the
The corresponding line impedance of j energy-storage units.
6. the charge-discharge control system of energy-storage units in a kind of distributed energy storage direct-current grid characterized by comprising described
The corresponding controller of all energy-storage units in distributed energy storage direct-current grid；
In discharge regime, the corresponding controller of p-th of energy-storage units controls its electric discharge, the corresponding institute of q-th of energy-storage units
It states controller and controls its electric discharge, and work as SOCp> SOCqWhen, the corresponding controller of p-th of energy-storage units controls it and puts
The discharge current of electricity is greater than the discharge current that the corresponding controller of q-th of energy-storage units controls its electric discharge；
In the charging stage, the corresponding controller of p-th of energy-storage units controls its charging, q-th of energy-storage units
The corresponding controller controls its charging, and works as SOCp> SOCqWhen, the corresponding controller of p-th of energy-storage units
The charging current for controlling its charging is greater than the charging electricity that the corresponding controller of q-th of energy-storage units controls its charging
Stream；
Wherein, p and q is the number of any two energy-storage units in the distributed energy storage direct-current grid, SOCpFor the pth
The state of charge of a energy-storage units, SOCqFor the state of charge of q-th of energy-storage units.
7. the charge-discharge control system of energy-storage units in a kind of distributed energy storage direct-current grid according to claim 6,
It is characterized in that, the corresponding controller of each energy-storage units executes governing equation based on control are as follows: udcj=
udcref-Kj·idcj·Gj, in formula, j indicates the number of any energy-storage units in the distributed energy storage direct-current grid, udcjTable
Show the output voltage of the corresponding controller of j-th of energy-storage units, udcrefIndicate preset voltage reference value, KjIndicate jth
The corresponding sagging coefficient of a energy-storage units, idcjIndicate the output electric current of the corresponding controller of j-th of energy-storage units, GjTable
Show the corresponding balance factor of j-th of energy-storage units, is the function of the state of charge of j-th of energy-storage units.
8. the charge-discharge control system of energy-storage units in a kind of distributed energy storage direct-current grid according to claim 7,
It is characterized in that, the balance factorIn formula, n indicates the charged of j-th of energy-storage units
State value SOCjPower exponent, value is positive number, R indicate it is preset be greater than 1 any positive number, idcj> 0 indicates discharge regime,
idcj< 0 indicates the charging stage.
9. the charge-discharge control system of energy-storage units in a kind of distributed energy storage direct-current grid according to claim 8,
It is characterized in that, the value of the n is any positive integer less than 10.
10. according to the charge and discharge of energy-storage units in a kind of described in any item distributed energy storage direct-current grids of claim 6 to 9
Control system, which is characterized in that the governing equation are as follows: udcj=udcref-Kj·idcj·Gj+rj·idcj, wherein rjIndicate the
The corresponding line impedance of j energy-storage units.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111181207A (en) * | 2020-01-07 | 2020-05-19 | 重庆理工大学 | Distributed lithium battery pack energy storage system |
| CN111244931A (en) * | 2020-01-18 | 2020-06-05 | 武汉船用电力推进装置研究所（中国船舶重工集团公司第七一二研究所） | SOC self-balancing control method for parallel operation of multiple energy storage modules |
| CN111313527A (en) * | 2020-02-27 | 2020-06-19 | 新疆中兴能源有限公司 | Method for controlling power balance of direct current micro-grid system |
| CN113141035A (en) * | 2020-01-17 | 2021-07-20 | 株式会社东芝 | Charge/discharge control device, charge/discharge system, charge/discharge control method, and storage medium |
| CN115224718A (en) * | 2022-09-20 | 2022-10-21 | 西安热工研究院有限公司 | Self-adaptive droop control method and system for energy storage converter |
| WO2023039888A1 (en) * | 2021-09-18 | 2023-03-23 | 宁德时代新能源科技股份有限公司 | Charging method, charging device and charging system for power battery |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103560546B (en) * | 2013-11-11 | 2015-07-01 | 东南大学 | Method for improving droop control in energy storage charge state |
-
2019
- 2019-03-04 CN CN201910158768.4A patent/CN109904850B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103560546B (en) * | 2013-11-11 | 2015-07-01 | 东南大学 | Method for improving droop control in energy storage charge state |
Non-Patent Citations (2)
| Title |
|---|
| THIAGO RIBEIRO OLIVEIRA等: "Distributed Secondary Level Control for Energy Storage Management in DC Microgrids", 《IEEE TRANSACTIONS ON SMART GRID》 * |
| 李鹏程等: "改进SOC下垂控制的分布式储能系统负荷电流分配方法", 《中国电机工程学报》 * |
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| CN111181207A (en) * | 2020-01-07 | 2020-05-19 | 重庆理工大学 | Distributed lithium battery pack energy storage system |
| CN113141035A (en) * | 2020-01-17 | 2021-07-20 | 株式会社东芝 | Charge/discharge control device, charge/discharge system, charge/discharge control method, and storage medium |
| CN113141035B (en) * | 2020-01-17 | 2024-05-10 | 株式会社东芝 | Charge/discharge control device, charge/discharge system, charge/discharge control method, and storage medium |
| CN111244931A (en) * | 2020-01-18 | 2020-06-05 | 武汉船用电力推进装置研究所（中国船舶重工集团公司第七一二研究所） | SOC self-balancing control method for parallel operation of multiple energy storage modules |
| CN111244931B (en) * | 2020-01-18 | 2021-08-17 | 武汉船用电力推进装置研究所（中国船舶重工集团公司第七一二研究所） | SOC self-balancing control method for parallel operation of multiple energy storage modules |
| CN111313527A (en) * | 2020-02-27 | 2020-06-19 | 新疆中兴能源有限公司 | Method for controlling power balance of direct current micro-grid system |
| WO2023039888A1 (en) * | 2021-09-18 | 2023-03-23 | 宁德时代新能源科技股份有限公司 | Charging method, charging device and charging system for power battery |
| CN116137940A (en) * | 2021-09-18 | 2023-05-19 | 宁德时代新能源科技股份有限公司 | Charging method, charging device and charging system of power battery |
| CN116137940B (en) * | 2021-09-18 | 2024-02-20 | 宁德时代新能源科技股份有限公司 | Charging method, charging device and charging system of power battery |
| CN115224718A (en) * | 2022-09-20 | 2022-10-21 | 西安热工研究院有限公司 | Self-adaptive droop control method and system for energy storage converter |
| CN115224718B (en) * | 2022-09-20 | 2023-02-03 | 西安热工研究院有限公司 | Self-adaptive droop control method and system for energy storage converter |
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