At present, the domestic and international power battery pack energy management system of developing generally all is that angle from safety designs.Strict, general battery management system only possesses the function of battery detection.This system can monitor the state parameter of battery, and all kinds of faults are reported to host computer by bus communication technology.On security standpoint, common battery management system is mostly controlled this Several Parameters of charging cut-ff voltage, discharge cut-off voltage and battery temperature of battery by analog circuit, be not damaged to guarantee battery.Like this, it has just simply realized equalizing charge in fact at most, does not have the function of balanced discharge.When some batteries occurred discharge by voltage in the Battery pack, whole Battery pack just can not have been worked, and causes the very big wasting of resources, has reduced the continuous mileage that makes of electric automobile.And it generally is static to the estimation of battery dump energy (State of Charge is called for short SOC), and ratio of precision is lower, and real-time is not strong.Generally speaking, this power battery management system just designs based on safety, it is not EMS truly, and its only judges by voltage according to charging, the discharge of battery and whether discharges and recharges (can be referred to as two point control), can only satisfy the basic demand of pure electric automobile.For mixed power electric car, in control strategy, general all the requirement battery operatedly neither filled full efficiency operation section of also not giving out light, and the battery management system (bms) of this like this two point control can say that without any meaning it can not satisfy the requirement of mixed power electric car.
Realize battery management system (bms) truly, topmost problem is monitoring, battery SOC prediction and the battery balanced realization of battery status, and this also is the technological difficulties place.The Single Chip Microcomputer (SCM) system of growing maturation can be gathered voltage, electric current and the temperature signal of battery, adopt electronic control unit (the Electric Control Unit of the feasible management of CAN bussing technique battery, be called for short ECU) can make things convenient for, carry out in real time communication with host computer, this makes the monitoring of battery status be easy to realize.Battery SOC is an important parameter of weighing the storage battery dump energy.Obtaining battery pack SOC value under the vehicle operating condition in real time and reliably, is the most primary task of fundamental sum of battery management system.According to the SOC of battery pack, can predict electric automobile continual mileage, control battery maximum discharge current or adjust the power distribution strategies etc. of electronic power vehicle multi-energy power assembly.Certainly also can tell performance difference between battery, realize charge and discharge balancing, keep the consistency between the battery, keep battery pack operate as normal and extending battery life as the foundation of balance charge/discharge according to the size of monocell SOC.The battery SOC Predicting Technique is all not too perfect at home and abroad, particularly is difficult to realize the online in real time estimation, and general error is about 10%.For the realization of balance charge/discharge, only consider equalizing charge in the general research work at home and abroad, very few to balanced discharge research.Giving after every batteries all is equipped with a charger, by charge independence that just can the simple realization battery to the control of charging enable signal, thereby the realization equalizing charge, and balanced discharge be implemented in the technical very big difficulty that has.
Summary of the invention
The objective of the invention is to overcome the shortcoming of prior art, a kind of collective and distributive type power batteries dynamic equilibria management system is provided.
Purpose of the present invention is achieved through the following technical solutions:
A kind of collective and distributive type power batteries dynamic equilibria management system, this system comprises battery detection subsystem (7), battery balanced subsystem, battery management subsystem and host computer; Described battery detection subsystem mainly is made up of a plurality of cell sampling modules, each cell sampling module is connected with a cell of battery pack by cable respectively, adopt monobus to connect between each cell sampling module, and be connected with the battery management subsystem by monobus; Described battery management subsystem comprises with the microcontroller being battery management ECU, multichannel communicating circuit and bus communication module and the passage gating control signal module of core, this ECU is to be core with integrated IC chip CPU with I/O module and SCI, SPI and CAN communication module, is aided with that peripheral circuit forms; Host computer is connected by the bus communication module of communication bus with the battery management subsystem; Described battery balanced subsystem is connected to form by a plurality of cell balance modules and channel selection circuit, the cell balance module respectively with the battery management subsystem) be connected, channel selection circuit is connected with the battery management subsystem with the cell of battery pack respectively.
Described cell sampling module comprises bleeder circuit, shunt, filter circuit, battery detection chip DS2348, drive circuit and high-speed light lotus root buffer circuit; Described bleeder circuit is connected with the charging cell respectively with shunt one end, the other end is connected with filter circuit respectively, filter circuit is connected with the cell sampling module, battery detection chip DS2348 is connected with drive circuit by monobus, drive circuit is connected with high-speed light lotus root buffer circuit by monobus, and high-speed light lotus root buffer circuit is connected with the multichannel communicating circuit of battery management subsystem by monobus; Other battery detecting module is connected with the multichannel communicating circuit by monobus; Battery detection chip DS2348 also is connected with the DC/DC insulating power supply.The cell sampling module is to adopt the monobus working method to the status monitoring of cell, and the data of turnover chip are finished by a single data, address, power supply multiplexing line.Communication between battery detection subsystem 7 and the battery management subsystem relies on monobus to finish, and battery management subsystem and host computer are to finish by communication bus (as monobus, CAN bus, FlexRay bus etc.).
Described cell balance module comprises DC-DC (DC/DC) chopper circuit, isolation drive and pulse-width modulation (PWM) controller, and described DC/DC chopper circuit one end is connected with high-voltage bus, and the other end is connected with channel selection circuit; Described DC/DC chopper circuit also is connected with the PWM controller by isolation drive; the PWM controller is connected with the battery management subsystem respectively, receives that charging from the battery management subsystem enables, the control command of overheat protector, overcurrent protection, overvoltage protection and charge strength.Battery balanced subsystem carries out equalizing charge according to the instruction of battery management subsystem to the battery that needs equalizing charge.The charging enable signal provides a switching value signal that whether charges for each charging module, and the charging current control signal is that control should be charged to storage battery with great electric current.In battery balanced subsystem, the control command that the battery management subsystem is sent, comprise that enable signal and charge strength signal are by after isolating, can be directly as the Control Parameter of pulse-width modulation output module, control the switch and the charge strength of charger, can realize the switch of this battery balanced subsystem and the adjusting of charge strength like this.Battery balanced module is equivalent to one on function can programme controlled intelligent charging machine.
Described channel selection circuit is preferably matrix switch, described matrix switch is formed matrix by n * m switch, each switch has two kinds of selectable connected modes, wherein n is the number of cell balance module, m is the number of cell 5,1≤n≤m, n and m are positive integer, each cell balance module 2 can carry out equalizing charge as required in m the cell any one, and n cell balance module can carry out equalizing charge for n battery in m the cell simultaneously.The outfit of equalizing charge module is not the whole power battery group (is made up of m cell before adopting, m〉1, m is a positive integer) way of the corresponding vehicle-mounted charge module of each cell, but be equipped with the individual vehicle-mounted charge module of n (integer of 1≤n≤m), this n charging module is connected with battery pack by channel selection circuit, control by battery management ECU, dynamically for the minimum cell of n dump energy (being SOC) in the battery pack m battery charges as required, thereby the equalizing charge function is is dynamically patrolled and examined in realization.
Described battery management subsystem and battery detection subsystem to obtain the state information of each cell, after data are handled, send the control signal to battery balanced subsystem by the monobus communication.The battery management subsystem can carry out communication by communication bus and host computer.Battery management subsystem ECU main program calls current signal collection, voltage signal acquisition, temperature signal collection subprogram, then by calculation process, charging enables control, charging current control and bus communication control.
The present invention has following advantage and beneficial effect with respect to prior art:
(1) battery monitor system adopts the monobus local area network (LAN), and on-site signal and battery management ECU have good isolation, and this isolation based on digital signal has a good guarantee to the precision of parameter measurement.
(2) charge and discharge balancing of battery adopts a Battery pack to be equipped with the mode that is no less than or equals cell several chargers, and the equilibrium of battery control is more flexible like this, has avoided man-to-man allocating method, has reduced cost, has improved the reliability of system.
(3) formed new system has compact topological layout, has realized centralized monitor, disperses the way to manage of dynamic equalization, and it possesses good adjusting control performance and higher reliability.
For further understanding the present invention, the present invention is further illustrated below in conjunction with drawings and Examples, but the scope of protection of present invention is not limited to the scope of embodiment statement.
The system of this invention forms and operation principle, and existing to select circuit with multichannel be that the scheme of matrix switch is an example, sets forth in conjunction with Fig. 2～Fig. 5.
As shown in Figure 1, a kind of collective and distributive type power batteries dynamic equilibria management system comprises battery detection subsystem 7, battery balanced subsystem 1, battery management subsystem 12 and host computer 10; Battery detection subsystem 7 mainly is made up of a plurality of cell sampling modules, each cell sampling module is connected with a cell 5 of battery pack 4 by cable 15 respectively, adopt monobus 9 to connect between each cell sampling module, and be connected with battery management subsystem 12 by monobus 9; Battery management subsystem 12 comprises with the microcontroller being battery management ECU, multichannel communicating circuit 23 and bus communication module and the passage gating control signal module of core, this ECU is to be core with integrated IC chip CPU with I/O module and SCI, SPI and CAN communication module, is aided with that peripheral circuit forms.Host computer 10 is connected with the bus communication module of battery management subsystem 12 by communication bus 11; Described battery balanced subsystem 1 is connected to form with channel selection circuit 3 by a plurality of cell balance modules 2, each cell balance module 2 is connected with battery management subsystem 12 respectively by holding wire 13, channel selection circuit 3 is connected with the cell 5 of battery pack 4 respectively, and connects with battery management subsystem 12 by holding wire 14.Battery pack 4 is connected with high-voltage bus 6.In this system, the ECU of battery management subsystem handles signal later can send to host computer 10 with the signal of needs through communication module, simultaneously battery management subsystem 12 also by charging enable, charge strength control and channel selecting signal control battery balanced subsystem 1 through holding wire 13 and 14.The power supply of battery balanced subsystem 1 provides (not drawing among the figure) by battery pack high-voltage bus 6, and the output of battery balanced subsystem is connected on the battery pack 4 by cable 16, and the selection of channel selection circuit 3 has been passed through in the centre.
The principle of cell sampling module as shown in Figure 2, the cell sampling module comprises bleeder circuit 19, shunt 25, filter circuit 20, battery detection chip DS2348, drive circuit 21 and high-speed light lotus root buffer circuit 22; Described bleeder circuit 19 is connected with charging cell 5 respectively with shunt 25 1 ends, the other end is connected with filter circuit 20 respectively, filter circuit 20 is connected with battery detection chip DS2348, battery detection chip DS2348 is connected with drive circuit 21 by monobus 9, drive circuit 21 is connected with high-speed light lotus root buffer circuit 22 by monobus 9, and high-speed light lotus root buffer circuit 22 is connected with the multichannel communicating circuit 23 of battery management subsystem 12 by monobus 9; Other battery detecting module is connected with multichannel communicating circuit 23 by monobus; Battery detection chip DS2348 also is connected with DC/DC insulating power supply 24.Its operation principle: at first the voltage of cell 5 is by after bleeder circuit 19 dividing potential drops, processing via filter circuit 20, be connected to battery detection chip DS2348, and the charging current signal of cell 5 is to be converted to voltage signal through shunt 25, and wave circuit 20 is connected to battery detection chip 38 after filtration again.Battery detection chip DS2348 carries by temperature detecting module, and its power supply is provided by DC/DC insulating power supply 24.The data that battery detection chip DS2348 collects are transmitted by monobus.Be connected on the amplification driving circuit 21 behind the digital signal process monobus communication cable 9, then through sending on the monobus behind the high-speed light lotus root buffer circuit 22.Also there is the detection module of a lot of other batteries on the monobus, has some multi-core sockets in the communicating circuit 23, to connect these battery detecting modules.
Fig. 3 is the schematic diagram of the battery balanced module 2 of battery balanced subsystem 1.As shown in Figure 3, cell balance module 2 comprises DC/DC chopper circuit 26, isolation drive 29 and PWM controller 28, and described DC/DC chopper circuit 26 1 ends are connected with high-voltage bus 6, and the other end is connected with channel selection circuit 3; Described DC/DC chopper circuit 26 also is connected with PWM controller 28 by isolation drive 29; PWM controller 28 is connected with battery management subsystem 12 respectively, receives that charging from battery management subsystem 12 enables, the control command of overheat protector, overcurrent protection, overvoltage protection and charge strength.Battery balanced module 2 is equivalent to one on function can programme controlled intelligent charging machine.During work, charging enables to control block and a switching value signal that whether charges is provided for charging module 2, and the charging current control signal is that control should be charged to storage battery with great electric current.In battery balanced subsystem 1, control command from battery management subsystem 12, comprise that enable signal and charge strength signal are by after isolating, can be directly as the Control Parameter of pulse-width modulation output module, control the switch and the charge strength of charging module 2, can realize the switch of battery balanced subsystem and the adjusting of charge strength like this.Main circuit is that battery pack high-voltage bus 6 becomes the single battery equalizing voltage after by DC/DC chopper circuit 26.Finally be connected on the cell 5 that needs equalizing charge through behind the channel selection circuit 3.DC/DC chopper circuit 26 is controlled by PWM controller 28, and the PWM ripple that PWM controller 28 produces can directly drive switching tube in the chopper circuit through behind the isolated drive circuit 29.The control signal of PWM controller 28 is provided by battery management subsystem 12, also carries some temperature, electric current and voltage acquisition module in this module, and they force out-of-work signal for PWM controller 28 provides, to guarantee safety.Battery management subsystem 12 can send channel selecting signal and come control channel to select circuit 3 after collecting the state of each battery, and the battery that respectively needs equalizing charge is charged.Simultaneously, it also can export charging enable signal, charge strength signal and overtemperature and overcurrent overvoltage protection signal.Whether the output of charging enable signal control PWM ripple, and the duty ratio of the charge strength Signal Regulation PWM ripple behind the battery management subsystem process D/A change-over circuit 27 is to reach the purpose of control charging current size.
Fig. 4 is the schematic diagram of the channel selection circuit 3 of matrix switch type.As shown in Figure 4, channel selection circuit 3 is a matrix switch, described matrix switch is formed matrix by n * m switch, each switch has two kinds of selectable connected modes, wherein n is the number of cell balance module 2, m is the number of cell 5,1≤n≤m, n and m are positive integer, each cell balance module 2 can carry out equalizing charge as required in m the cell any one, and n cell balance module can carry out equalizing charge for n battery in m the cell simultaneously.This n charging module is connected with battery pack by matrix switch formula channel selection circuit, control by battery management ECU, dynamically for the minimum cell of n dump energy (being SOC) in the battery pack m battery charges as required, thereby the equalizing charge function is is dynamically patrolled and examined in realization.Its operation principle is: after battery management subsystem 12 is judged the SOC of m cell 5 in the battery pack 4, through comparative analysis, judge wherein n cell 5 that SOC is minimum, and calculate the required separately equalizing charge size of current of this n cell 5, send control signal and give channel selector switch 3 and battery balanced subsystem 1, battery balanced subsystem 1 carries out equalizing charge according to the instruction of sending to n the minimum cell of SOC.The matrix switch advantage is, n battery balanced module 2 do not bound one by one with m cell 5, but as required, dynamic assignment is carried out equilibrium for which cell.In case certain battery balanced module 2 breaks down, battery management subsystem 12 can stop its work, and then remaining (n-1) individual battery balanced module 2 can operate as normal, can carry out equilibrium simultaneously for (n-1) in m the cell 5 is individual at every turn.So circulation, m cell all can obtain balanced management.
The method for designing that adopts system of the present invention, in battery management subsystem 12, main program calls current signal collection, voltage signal acquisition, temperature signal collection subprogram, gather relevant informations by battery detection subsystem 7, then by calculation process, charging enables control, charging current control and CAN bus communication.Battery detection is one of task of battery management, and it is gathered the state of battery.In the middle of the process that the data that collect are handled; program can be differentiated the state of battery with certain specific algorithm; battery charge state etc. for example, and then judge unbalanced battery and all kinds of fault-signal, comprise temperature protection signal, voltage protecting signal and current protection signal etc.When needs carry out equalizing charge to certain battery, send battery gating signal, charging enable signal and charge strength signal by the battery management subsystem and control the selection to the need balancing battery, the switch of charger and the adjusting of charge strength.Battery detection subsystem 7 and each cell sampling module and battery management subsystem 12 come communication by monobus, and communication strictly observes monobus lin protocol.After start, at first carry out the self check of monobus at the battery management subsystem, whether the work of differentiating monobus is normal, and normal words then begin the communication with each monobus node, realize patrolling and examining of each cell 5.Each battery prison sampling block all has a slice battery detection chip DS2438, is responsible for gathering the state of battery.In the process that battery management subsystem 12 is patrolled and examined, at first chip is carried out homing action, after receiving answer signal, send voltage, electric current and temperature transition instruction, be to wait for that after changing successfully, the battery management subsystem just begins to read the value of conversion then.Take turns after battery patrols and examines end one, the battery management subsystem just begins patrolling and examining of a new round.In this process, battery management subsystem 12 also carries out communication with host computer 10 by CAN bus other buses such as (or) FlexRay simultaneously, after the analytical sampling data, various information is reported to host computer 10.
The parameter that generally need gather the collection of battery status has: bus voltage, bus current, single battery voltage, monocell euqalizing current and battery temperature.Obtaining of bus voltage must possess pinpoint accuracy, can realize by high-precision isolation voltage acquisition module.Current sample can be with possessing high-precision isolation current acquisition module.To the collection of cell parameter, in the battery pack that is made of the cell polyphone, the earth potential of every batteries is inconsistent, and electromotive force differs big especially.Simply can not achieve the goal with multi-channel A/D sampling.The present invention is to the isolation of monomer battery voltage signal, and signal can be altogether the most at last.When signal was isolated, the present invention taked the light-coupled isolation chip that digital quantity is isolated.
The collection that realizes battery status generally has following scheme: present embodiment adopts the independent sample scheme to avoid patrolling and examining the shortcoming of sampling, is equipped with independently battery status monitoring modular by giving each battery, comes communication by data in each acquisition system.In the present invention, 7 employings of battery detection subsystem are the battery sampling module of core with the DS2438 chip.DS2438 is the reserve battery detection chip that DALLAS company produces, and it is the monobus working method, and the data of turnover chip are finished by a data lines, address, power supply multiplexing line.It is the ECU of core that the battery management subsystem adopts the MC9S12DB128 single-chip microcomputer with 16 HCS12 Series of MCU of high-performance of Motorola, abundant I/O module and a series of communication modules such as SCI, SPI, CAN that this chip is integrated are carried out communication with host computer by the CAN bus.Battery detection subsystem of the present invention 7 adopts the monobus local area network (LAN)s, and on-site signal and battery management subsystem 12 have good isolation, and this isolation based on digital signal has a good guarantee to the precision of parameter measurement.The charge and discharge balancing of battery adopts a Battery pack to be equipped with the mode of no more than battery several charging modules, has avoided man-to-man allocating method, has reduced cost, has improved the reliability of system.
The working condition of native system under various patterns is as follows:
(1) parking balanced mode.If the battery balanced process in the process of vehicle ' does not finish, after vehicle stops to travel, only want to cut off car load high pressure and 24V low pressure, system still proceeds battery balanced.
(2) parking external charge pattern.This pattern can realize the regular equalizing charge maintenance of battery.Battery management system has a mode selection switch, i.e. balanced mode and charge mode.Battery is after stopping using, if the dump energy deficiency, can the external charge machine to battery balanced.External charge has 3 kinds of patterns, promptly straight mold filling formula, charge mode and the fast mold filling formula of mixing.Under straight mold filling formula, the external charge machine directly connects battery pack, to the charging of battery pack polyphone.This moment, charging current was more flexible, can large current charge also can low current charge, and the battery equalization subsystem works in balanced mode.Under charge mode, the external charge machine does not directly connect battery pack, but only connects the battery equalization subsystem, and this moment, battery balanced subsystem work was in charge mode.This pattern need be cut off being connected of battery equalization subsystem and battery pack simultaneously.Under this charge mode, the battery equalization subsystem is to the battery charge independence, to reach battery balanced purpose.Another is to mix fast mold filling formula, promptly now directly fills, and all fills again, can improve charging and balanced efficient like this, reaches the purpose of filling soon.
(3) driving balanced mode.There is unbalanced phenomenon in vehicle if find certain battery in the process of moving, and the battery equalization subsystem will be come unbalanced battery balanced on the battery pack high-voltage bus in power taking.When driving, judging which battery or which battery are unbalanced is determined by control strategy.
(4) driving electric energy feedback model.This pattern is a very big special feature after electric automobile has adopted battery equalization system.Common electric automobile if generating voltage is lower than battery voltage, then can only be given batteries charging by the DC/DC pump pressure afterwards again when carrying out the electric energy feedback.And the service voltage scope of battery equalization subsystem is more extensive, such as working between 150v-500v, even generating voltage is lower than assembled battery total voltage like this, also can absorb the electric energy of feedback by the battery equalization subsystem.This pattern needs battery management ECU to start according to the current state of car load, and it need cut off being connected of battery equalization subsystem and battery pack simultaneously.
(5) driving charge mode.This pattern can provide brand-new driving charging method to mixed power electric car.It does not need generator that the high pressure that is higher than the battery pack bus voltage is provided, and the low pressure that is produced when generator works in the slow-speed of revolution also can be come to equalizing charge of battery by the battery equalization subsystem.This pattern also needs battery management ECU to start according to the current state of car load, and it need cut off being connected of battery equalization subsystem and battery pack.
Fig. 5 is the schematic diagram of packet type channel selector switch.As shown in the figure, be connected by the channel switch more than 1 pair 31 between battery balanced module 2 and the little Battery pack.For simplied system structure and reduce cost, channel selector switch can be selected the packet type management for use.M the cell 5 that is about to power battery pack is divided into n group on arranging, be equipped with n battery balanced module 3, and each battery balanced module 3 connects one to one with the little Battery pack of n.Battery detection subsystem 7 is identical with embodiment 1 with battery management subsystem 12.The advantage of this scheme is the fixing management of each battery balanced subsystem 1 a little Battery pack, and channel switch is simple in structure, is convenient to debugging.The operation principle of remainder is identical with embodiment 1.