Background technology
In the generation of electricity by new energy field, adopt extensive accumulate technology, can make the power output of unsettled new forms of energy electric power smoothly adjustable, unsettled electric energy input is become continuous, safe and reliable electric energy output, reduce of the impact of fluctuation electric energy, a difficult problem thereby solution new forms of energy electric power is incorporated into the power networks to electrical network.For island, remote districts etc. from the net generation of electricity by new energy, extensive power storage system can realize that electric power smoothly reaches storage, with satisfy island, remote districts etc. from the net generating and do not have the exert oneself regular supply of electric power under the situation of new forms of energy.
Fail safe, energy storage efficiency are two important parameters investigating energy-storage system.Temperature is the important external factor that influences battery cell charge/discharge capacity, energy-storage battery security of system; The internal resistance of battery and module are interior, the consistency of intermodule battery then is the important internal factor that influences the energy-storage system performance.Extensive energy storage need be got up a large amount of cell connection in series-parallel to obtain the output of bigger stored energy capacitance and higher-wattage, and under the situation of considering fail safe, the energy storage size of battery pack depends on the charge-discharge characteristic that differs from a batteries most.Because might not being same batch of manufacturing and manufacture process itself, battery has certain otherness, and along with the battery growth of service time, the mutual difference of battery performance can be more remarkable, and the cell of series connection is many more, and inconsistency is just more outstanding.If battery is not carried out balanced management, along with charge and discharge cycles is carried out, the inconsistent meeting between cell causes and owes charging, overcharges and overdischarge, has a strong impact on the serviceability and the life-span of battery pack, and can cause serious potential safety hazard.
Existing balancing technique, what use at most is only to use resistance battery pack is carried out the dissipative type equilibrium in charging process, the balanced principle of resistance is as shown in Figure 1.The problem of this balanced way maximum is that resistance can produce a large amount of heat in balancing procedure, has reduced efficiency for charge-discharge, causes the huge waste of effective storage power; Produce a large amount of heat simultaneously, also increased the burden of heat management.Existing non-dissipative type equalization methods mainly comprises switching capacity equalization methods etc., but tends to exist circuit complexity, balancing speed to wait problem slowly.
Therefore, prior art has yet to be improved and developed.
Summary of the invention
The object of the present invention is to provide a kind of equalization scheme of energy-storage system, be intended to solve existing resistance dissipative type balanced way and in balancing procedure, produce a large amount of heat, cause the huge waste of effective storage power; Produced simultaneously big calorimetric, the problems such as burden of increase heat management.Solve simultaneously, by single equilibrium slow problem of balancing speed in big capacity energy storage system.
Technical scheme of the present invention is as follows:
A kind of equalizing system of energy-storage system, wherein, comprise Blast Furnace Top Gas Recovery Turbine Unit (TRT), electric energy combination system, dc bus, charging module, batteries, combining inverter, line module, constant-current source, balanced power input, described Blast Furnace Top Gas Recovery Turbine Unit (TRT) is connected on the electric energy combination system, described electric energy combination system connects charging module by dc bus, and described charging module connects batteries; Be connected with combining inverter and line module on the described dc bus in turn, constant-current source is connected on the line module, to change direct current into through the alternating current behind the inverter, and be connected to batteries by the equalizing bus bar that is connected on the balanced power input, constant-current source carries out equilibrium as balanced source to the battery cell in the batteries being transformed into direct current output through the output of the interchange behind the combining inverter.
The equalizing system of described energy-storage system, wherein, batteries comprises energy-storage module and energy storage control unit, the charging end of described energy-storage module all level is associated on the balanced power input, be connected in series between the output of energy-storage module, described energy storage control unit is connected to energy-storage module by the can bus.
The equalizing system of described energy-storage system, wherein, described energy-storage module comprises unit controls module, balanced Power Entry Module and monomer bag, the balanced Power Entry Module of described energy-storage module all is connected in parallel on the both positive and negative polarity of balanced power input; Unit controls module in the described energy-storage module is connected to energy storage control module by the can bus, and described unit controls module is connected to the monomer bag by the lin bus, and the equalizing bus bar of monomer bag is connected to balanced Power Entry Module.
The equalizing system of described energy-storage system wherein, comprises a plurality of energy-storage modules in the described batteries, the charging end of each energy-storage module all level is associated on the balanced power input.
The equalizing system of described energy-storage system, wherein, each energy-storage module comprises two or more monomer bags that are connected in series.
The equalizing system of described energy-storage system, wherein, each monomer bag comprises a cell, microprocessor and isolation module and positive limit, negative pole point, lin bus and equalizing bus bar, the two poles of the earth of described cell respectively correspondence be connected that positive limit and negative pole point are gone up and microprocessor on, described equalizing bus bar is connected on the microprocessor, described lin bus is connected on the microprocessor by isolation module, and described lin bus is connected on the control end; Described equalizing bus bar is connected on the balanced power input; Described positive limit is connected electric energy output end with negative pole point.
The equalizing system of described energy-storage system, wherein, energy transfer module in parallel on the electrode of each monomer bag, each energy transfer module disperses to be installed in parallel on balanced Power Entry Module.
A kind of equalization methods of energy-storage system, wherein, described microprocessor is gathered the voltage of each cell in the energy-storage module, and send to the energy storage control unit, described energy storage control unit calculates the average voltage of the cell in each energy-storage module, the average voltage of cell in a certain monomer battery voltage in a certain energy-storage module is lower than its place energy-storage module, then the microprocessor controls cell in the monomer bag is connected with equalizing bus bar, cell absorbs the electric current on the equalizing bus bar, begins this cell is carried out equilibrium; When this monomer battery voltage reached the average voltage of cell in the energy-storage module, cell and equalizing bus bar disconnected, and finish the equilibrium of this joint cell, and the cell to another joint low-voltage carries out equilibrium treatment then.
The equalization methods of described energy-storage system, wherein, the electric weight that will be higher than the cell of average voltage by energy transfer module with the energy branch mode is transferred on the equalizing bus bar and is absorbed by the battery cell that voltage is lower than average voltage.
The equalization methods of described energy-storage system, wherein, if the voltage of all cells in a certain energy-storage module is all balanced, but be lower than the average voltage between each energy-storage module in the energy-storage system, then all cells of this energy-storage module are connected with equalizing bus bar, absorb the electric current on the equalizing bus bar, and each single battery in the energy-storage module is all mended, reach the average voltage of energy-storage units module up to the voltage of this energy-storage module, finish the equilibrium of energy-storage system.
Beneficial effect of the present invention: the present invention is by using the non-dissipative type energy transfer module simultaneously and being that the benefit electricity mode of constant-current source input is carried out equilibrium to the storage battery system with user load in the system, at any time can carry out equilibrium to single battery, as long as there is monomer battery voltage low, satisfy equilibrium condition, no matter energy-storage units or module are in charging, discharge or laying state, all can be balanced immediately, realize effective dynamic equalization, in balancing procedure, can not produce a large amount of heats in addition, improve efficiency for charge-discharge.
Embodiment
For making purpose of the present invention, technical scheme and advantage clearer, clear and definite, below develop simultaneously with reference to accompanying drawing that the present invention is described in more detail for embodiment.
Load type is mended the electrical equalization system and is comprised Blast Furnace Top Gas Recovery Turbine Unit (TRT), electric energy combination system, dc bus, charging module, batteries, combining inverter, line module, constant-current source, balanced power input.Blast Furnace Top Gas Recovery Turbine Unit (TRT) is provided with a plurality of in system provided by the invention, Blast Furnace Top Gas Recovery Turbine Unit (TRT) 1, Blast Furnace Top Gas Recovery Turbine Unit (TRT) 2 ..., Blast Furnace Top Gas Recovery Turbine Unit (TRT) n (wherein n is more than or equal to 2), and all be connected on the electric energy combination system, described electric energy combination system connects charging module by dc bus, and described charging module connects batteries; Be connected with combining inverter and line module on the described dc bus in turn, constant-current source is connected on the line module, will change direct current into through the alternating current behind the inverter.And be connected to batteries by the equalizing bus bar that is connected on the balanced power input.
The equalizing system of energy-storage system provided by the invention and equalization methods are to forward on the equalizing bus bar with the electric energy of energy branch mode with the high-voltage battery monomer, and are absorbed by the battery cell of low-voltage, carry out dynamic equalization.But when the energy shortage that the high-voltage battery monomer shifts is mended electricity to give the low-voltage monomer, as a supplement, the present invention also adopts the electric mode of mending: passing through constant-current source through the output of the interchange behind the inverter, be transformed into direct current output, as balanced source, flow into equalizing bus bar, monomer in the power storage system and unit are carried out equilibrium, improve balanced speed and effect.
Use the non-dissipative type energy transfer module storage battery system is carried out equilibrium.The thinking of the equilibrium that energy shifts is criterion for utilizing switch power technology with voltage, forwards on the equilibrium line with the electric energy of energy branch mode with the high-voltage battery monomer, and is absorbed by the battery cell of low-voltage, carries out dynamic equalization.
This energy shifts and replenishes in the equilibrium, energy transfer module in parallel on the electrode of each monomer bag, and each energy transfer module disperses to be installed in parallel on every joint storage battery, as shown in Figure 3.Energy transfer module is mainly used the DC/DC switch power technology, the electric weight of high-tension cell is transferred on the cell of low-voltage with the energy branch mode, it promptly is criterion with voltage, the energy that will be higher than the cell of average voltage with the energy branch mode is transferred on the equalizing bus bar, and is lower than the battery cell absorption of average voltage by voltage.It is that two-way simultaneous carries out that electric weight shifts, and the electric weight of promptly any joint high-voltage battery can both walk abreast simultaneously and transfer to any joint low-voltage battery, thereby reaches the equilibrium of cell voltage.
Microprocessor in the described monomer bag is gathered the voltage of each cell in the energy-storage units, the voltage data of monomer bag uploads to the energy storage control unit by Serial Peripheral Interface (SPI) (SPI) transmission means, energy storage control unit processor calculates the average voltage of cell in the energy-storage units, and its computing formula is: average voltage U
On averageWhether cell sum in=energy-storage module total voltage/energy-storage module needs balanced foundation as each cell, i.e. equilibrium makes workable foundation.
After monomer bag and energy transfer module join well, just begin balanced operation, energy transfer module detects the monomer bag cell voltage that it connected on one side, detect other monomer bag cell voltages by equalizing bus bar on one side, draw the battery pack average voltage, cell voltage and battery pack average voltage are compared, if cell voltage is higher than average voltage, circuit is by the DC/DC converter in the module, and the energy that will exceed flows into equalizing bus bar; If cell voltage is lower than average voltage, the electric weight that circuit absorbs on the equalizing bus bar in the module is given this battery charge.
Continuation is referring to Fig. 3, and among the present invention, energy shifts balanced way owing to be that bidirectional energy flows, and can carry out the infinite cascade of monomer.But in extensive battery energy storage system, number of batteries is numerous, in order to simplify battery management system, reduces the complexity of management, and guarantees balancing speed and efficient, and the battery energy storage system is divided into a plurality of unit, and balanced system is unit with the unit.The equilibrium of energy transfer type has low in power consumption, but balancing speed is slower.In order to improve balancing speed, the present invention proposes to use the external power supply equilibrium as a supplement on the basis of above-mentioned balanced way.Based on the equilibrium of energy transfer type, it is auxilliary mending electric formula equilibrium.
The basic principle of mending electric formula equilibrium is: referring to Fig. 2, load type that the embodiment of the invention one provides is mended the electrical equalization principle: will mend power supply and be used as a load among the user, external AC/DC constant-current source by equalizing bus bar, carries out equilibrium to the monomer bag of energy-storage module in the energy-storage system.
Constant-current source is worked as a load among the user, being transformed into direct current output through the output of the interchange behind the inverter, as balanced source, by the lin bus monomer in the module is carried out equilibrium, the can bus is carried out equilibrium to module, finishes the battery cell and the module of batteries in the power storage system are carried out equilibrium.
Because it is limited that constant-current source is mended electric weight, can not carry out equilibrium to whole energy-storage system simultaneously, in this balanced management method the batteries in the energy-storage system is divided into a plurality of energy-storage modules, as shown in Figure 5.Described batteries comprise first energy-storage module, second energy-storage module ..., n energy-storage module and energy storage control unit, described first energy-storage module, second energy-storage module ..., the n energy-storage module the charging end all level be associated on the balanced power input, be connected in series between the output of each energy-storage module.Described energy storage control unit connects each energy-storage module by the can bus.
Referring to Fig. 3, Fig. 5, described energy-storage module comprises unit controls module, balanced Power Entry Module and a plurality of monomer bag, and the balanced Power Entry Module of described each energy-storage module all is connected in parallel on balanced power input and gets on the both positive and negative polarity; Unit controls module in described each energy-storage module is connected to energy storage control module by the can bus, and described unit controls module is connected to each monomer bag by the lin bus, and the equalizing bus bar of each monomer bag is connected to balanced Power Entry Module.
In the present case, the each corresponding energy-storage module of constant-current source, constant-current source carries out equilibrium to corresponding energy-storage module and mends.Each energy-storage module comprises two or more monomer bags that are connected in series, referring to Fig. 4 is the internal structure schematic diagram of monomer bag, and each monomer bag comprises a cell, a microprocessor (MPU) and isolation module and positive limit, negative pole point, lin bus and equalizing bus bar.The two poles of the earth of described cell respectively correspondence be connected that positive limit and negative pole point are gone up and microprocessor on, described equalizing bus bar is connected on the microprocessor, described lin bus is connected on the microprocessor by isolation module, described lin bus is connected on the control end; Described equalizing bus bar is connected on the balanced power input; Described positive limit is connected electric energy output end with negative pole point.
Be criterion with voltage in the load type balanced way of the present invention,, the voltage of its and other battery maintained an equal level realize equilibrium by mending electricity to the low battery of voltage.Balanced order is carried out equilibrium to module and intermodule again for earlier each cell in the module being carried out equilibrium.
Microprocessor in the described monomer bag is gathered the voltage of each cell in the energy-storage module, after crossing Lin bus and isolation module, balanced enable pass inputs to microprocessor (MPU), MPU controls the annexation of single battery and equalizing bus bar again, connects to enter equilibrium state.The voltage data of monomer bag uploads to the energy storage control unit by Serial Peripheral Interface (SPI) (SPI) transmission means, and energy storage control unit processor calculates the average voltage of cell in the energy-storage module, and its computing formula is: average voltage U
On averageCell sum in=energy-storage module voltage/energy-storage module is as the foundation of intermodule equilibrium.
The equalization methods of said system is: a certain monomer battery voltage U in a certain energy-storage module
nBe lower than the average voltage of cell in this module, as U
n<U
On average, then begin cell n is carried out equilibrium.At this moment, the inner electronic switch of microprocessor MPU control in the monomer bag, switch closure, the electric current on the equilibrium line flows into single battery through electronic switch.If the voltage U of cell m
m, cell n voltage U
nAll less than average voltage U
On average, the MPU in cell m and the cell n all controls inner electronic switch, switch closure, and the electric current on the equilibrium line can flow into cell m, cell n simultaneously.Behind the electric voltage equalization of each cell in the module, then disconnect electronic switch.Thereby the equilibrium of monomer battery voltage in the realization energy-storage module.
Though, the electric voltage equalization between the cell in the energy-storage module, the global voltage U ' of each energy-storage module
nAnd between the global voltage of other energy-storage modules unbalanced problem may appear.
Therefore, if the voltage of all cells is all balanced in a certain energy-storage module, but the global voltage U ' of this energy-storage module
nBe lower than the average voltage U ' of the global voltage of each energy-storage module in the energy-storage system
On averageThen the balanced power supply of this energy-storage system (being constant-current source) all mends for all cells in this energy-storage module, reach the average voltage of the global voltage of energy-storage module up to the global voltage of this energy-storage module, then described energy-storage system finishes the equilibrium between energy-storage module.
Equalization scheme among the present invention is applicable to the power storage system of generation of electricity by new energy, is applicable to simultaneously to be applied in extensive battery power storage system such as power plant, intelligent grid.
The present invention is by using the non-dissipative type energy transfer module simultaneously and being that the benefit electricity mode of constant-current source input is carried out equilibrium to the storage battery system with user load in the system, at any time can carry out equilibrium to single battery, as long as there is monomer battery voltage low, satisfy equilibrium condition, no matter energy-storage units or module are in charging, discharge or laying state, all can be balanced immediately, realize effective dynamic equalization, in balancing procedure, can not produce a large amount of heats in addition, improve efficiency for charge-discharge.
Should be understood that application of the present invention is not limited to above-mentioned giving an example, for those of ordinary skills, can be improved according to the above description or conversion that all these improvement and conversion all should belong to the protection range of claims of the present invention.