CN203126558U

CN203126558U - Battery management system based on coprocessor and solid-state relay

Info

Publication number: CN203126558U
Application number: CN201320166593XU
Authority: CN
Inventors: 程勇; 王丽梅; 王宏栋; 刘斐
Original assignee: Shandong University
Current assignee: Shandong University
Priority date: 2013-04-03
Filing date: 2013-04-03
Publication date: 2013-08-14
Anticipated expiration: 2023-04-03

Abstract

The utility model discloses a battery management system based on a coprocessor and a solid-state relay. The battery management system is novel, low in self power consumption, based on an MC9S12XE single chip microcomputer (SCM), and capable of monitoring working state parameters of a battery and performing high-precision estimation on a system on a chip (SOC) of the battery to achieve insulation monitoring, fault grading alarm and balance management of the battery. The battery management system comprises a main control panel, a current acquisition board and a voltage acquisition board, wherein the current acquisition board and the voltage acquisition board are connected with the main control panel respectively; the main control board is connected with a total positive end and a total negative end of the high voltage respectively through high voltage connectors to achieve insulation monitoring of the high voltage and connected with a relay through a power drive connector; the current acquisition board is combined with a host processor through the coprocessor to achieve SOC estimation of the battery and connected with a current sensor through a current signal connector, and the current sensor is arranged between the relay and the high voltage; and the voltage acquisition board acquires voltage signals through an operational amplifier chip, and power supply of the operational amplifier chip is controlled by the solid-state relay.

Description

Battery management system based on coprocessor and solid-state relay

Technical field

The utility model relates to a kind of battery management system, is specifically related to a kind of battery management system based on coprocessor and solid-state relay.

Background technology

Battery is as the main propulsion source of electronlmobil, and the quality of its performance will directly affect the popularization of electronlmobil.Battery management system not only needs the mode of operation of Real-Time Monitoring battery, also needs the inconsistency that the battery after circulation is occurred to carry out equilibrium, thereby prevents over-charging of battery, cross and put, to improve the service life cycle of battery.

At present battery management system has all been carried out to a large amount of research both at home and abroad.For example the intelligent management system of AM General company can be realized the condition monitoring of cell and have equalization function, domestic hundred million can, power is high, hat is opened up with the product of the company such as Mo Gong, also has been widely used, but the problems such as during the ubiquity off working state of current battery management system the large and voltage acquisition precision of system power consumption is low, or the not high problem of estimation precision of the residual capacity of battery (State of Charge, SOC).

Battery management system is based on for the collection of cell pressure that chip integral body is gathered more or analog switch or solid-state relay carry out circle collection, increasing from consumption of current when front a kind of acquisition mode can cause the battery management system off working state, then a kind of mode will reduce the acquisition precision of voltage, also can reduce the reliability of battery management system simultaneously; On electronlmobil, the estimation for SOC is based on open circuit voltage method and ampere-hour integral method more at present, therefore the estimation rate of the sample rate of the estimation precision of initial SOC and electric current and SOC will affect the estimation precision of whole SOC.

Chinese patent CN 102975627A detects the type couple the USB device, and according to the type of this USB device, to this USB device charging.

Chinese patent CN 101141076A is connected to accessory feed or battery unit by contact relay by voltage detection unit, and during for definite startup or parking, whether the voltage detection unit circuit occurs extremely; Adopt the quantity of the battery unit relay corresponding with the battery unit total quantity to carry out the collection of cell pressure, this acquisition mode need to be to the battery unit relay break-make that circulated, affect the life-span of relay, in addition due to the pressure drop difference of relay, corresponding to the voltage acquisition precision of battery, also can descend.

Chinese patent CN 102064568A has adopted the LTC6802 coprocessor cell pressure to be gathered and exports balanced control signal, and carries out data exchange by spi bus and master controller, and still, this processing mode can't resolve the problem that improves the SOC precision.

To sum up, battery management system has two large difficult points:

The one: the high precision estimation of SOC, the estimation of high precision SOC comprises the high precision estimation of SOC in the high precision estimation of initial SOC and system work process, the utility model patent adopts open circuit voltage with the method that the ampere-hour integral method combines, SOC to be estimated, for the estimation of initial SOC, the open circuit voltage under different temperatures, different electric current and the charging and discharging state of the utility model employing difference under rest times and the relation of SOC are carried out initial SOC demarcation; SOC in system work process estimation adopts the ampere-hour integral method, and from ampere-hour integration ratio juris, the reason that affects the estimation precision of SOC in working process is that the computation speed of the sample rate of electric current and SOC is slow.

The 2nd, the cell pressure collection of low power consumption high-precision, collection for cell pressure at present mainly is divided into two large classes, one class is based on the voltage acquisition of chip, another kind of is to adopt the switches such as analog switch or solid-state relay to carry out circle collection to voltage, before a kind of acquisition mode caused that the consumable comparision of quantity of electricity during in off working state is large at battery management system, affect the continual mileage of batteries of electric automobile, rear a kind of mode is owing to adopting switch, the loss in voltage difference of each switch, thereby affect the high precision collecting of cell pressure, and the switching back and forth due to switch, reduced the reliability of battery management system.

Summary of the invention

The purpose of this utility model is for overcoming above-mentioned the deficiencies in the prior art, a kind of low-power consumption battery management system based on coprocessor and solid-state relay is provided, it is a kind of low novel battery management system from power consumption and high precision SOC estimation, based on the MC9S12XE micro controller system, can be monitored the working status parameter of battery to, the SOC of battery is carried out the high precision estimation, realizes that the insulating monitoring of battery, failure sorted report to the police and balanced management.

For achieving the above object, the utility model adopts following technical proposals:

A kind of battery management system based on coprocessor and solid-state relay, it comprises master control board and the connected current acquisition plate of difference and voltage acquisition plate, total anode and total negative terminal that described master control board connects respectively high-tension current by the high-tension current joint are realized the high-tension current insulating monitoring, by the power drive joint, succeed electrical equipment; The SOC that described current acquisition plate adopts coprocessor to be combined with primary processor and realizes battery estimates, connect current sensor by the current signal joint, described current sensor is arranged between relay and the total negative terminal of high-tension current; Described voltage acquisition plate gathers voltage signal by the amplifier chip, and the power supply of amplifier chip is controlled by solid-state relay.

Described system adopts the low pressure storage battery of the 12V/24V on electronlmobil to power to it through DC/DC isolation module separately respectively; Described system adopts the B0505 power supply chip to be isolated the communication power supply, and adopts the 6N137 high speed photo coupling to be isolated communication signal, to strengthen the antijamming capability of communication signal.

Described master control board comprises the USB memory module, for storing working status parameter.

Described master control board is connected with read-out, and described read-out is LCDs, realizes the real-time demonstration to working status parameter; Described master control board is also by CAN bus and electric vehicle instrument and entire car controller communication.

Described master control board also comprises power module I, main controller module I and communication module.

Described relay comprises total relay, module relay and charge relay, described total relay is connected to load, described load is connected to the total anode of high-tension current through wire fuse, described module relay is relay between battery pack, described battery pack is the cell number that every block of voltage acquisition plate is controlled, and described charge relay connects the battery charger signal.

Described current acquisition plate comprises power module II, main controller module II and current acquisition module.

Described current sensor is two-way Hall current sensor.

Described voltage acquisition plate connects respectively the temperature sensor that is arranged on the battery pack positive and negative terminals and the positive and negative terminal of battery by temperature signal joint and voltage signal joint, and described voltage acquisition plate has several, and each voltage acquisition plate corresponds to many 8 batteries.

Described voltage acquisition plate is connected with balancing disk by the balancing disk joint.

Described voltage acquisition plate comprises power module III, main controller module III, voltage acquisition module and temperature collection circuit.

Described voltage acquisition module comprises the voltage signal joint, diode, solid-state relay, op amp 1-8, the voltage of high-tension battery is received the anode of diode D1-D6 through the overvoltage signal joint, the negative electrode of diode D1-D6 connects the pin 8 of solid-state relay, the pin 1 of solid-state relay connects positive source, pin 2 is through resistance R 1 ground connection, pin 7 is through capacitor C 1, C2, C3 powers to amplifier chip 1-8, single-unit high-tension current anode connects the in-phase input end of amplifier chip 1-8 through resistance R 3, negative pole connects the reverse input end of amplifier chip 1-8 through resistance R 4, in-phase input end is through resistance R 2 ground connection in addition, reverse input end connects the mouth of op amp through resistance R 5, the mouth of op amp is through resistance R 1, C2 connects the AD sample port of master chip.

Described current acquisition module comprises current signal processing module, current signal collection module and SOC estimation block, the utility model adopts two-way Hall element, because the reference voltage of AD sampling A/D chip is 5V, in order to reduce the complexity of circuit, the electric current of-100mA-100mA, at first through the voltage of change into-2.5V-2.5V of 25 ohmages, then is changed into signal to the electric signal of 0V-5V through the 2.5V reference voltage.Forefathers' large result shows between aperture voltage and SOC to exist certain relation, the utility model is in order to improve the estimation precision of SOC, the method that has adopted open circuit voltage to combine with the ampere-hour integral method, in order to improve the estimation precision of initial SOC, according to the open circuit voltage under the different temperatures, different electric current and the charging and discharging state that obtain under different rest times and the relation of SOC, initial SOC value is demarcated, estimation employing ampere-hour integral method due to SOC in system work process, the computing formula of ampere-hour integral method is as follows

can calculate the current integration value by constantly the flow through current i (t) of battery pack of accurate Calculation k-1 to k, add the correction of charge discharge efficiency, just can obtain current SOC with the initial condition addition of battery pack, from surface analysis can find out, in order to improve the estimation precision of SOC in working process, need to improve the sample rate of electric current and the estimation rate of SOC, the utility model is based on the MC9S12XE micro controller system, the mode that adopts coprocessor to combine with primary processor, main program is gathered current signal always, coprocessor interrupts being processed to SOC computation period timer, and by dual port RAM and primary processor exchanging electric current data, thereby realize the estimation of SOC.The utility model is also studied as electric current, temperature, ageing state, self-discharge the influence factor of capacity of cell in addition, has obtained the correction of the relation curve of above-mentioned parameter and capacity of cell for capacity.

During system works master control board every 100ms with the current acquisition plate, the order of several voltage acquisition plates obtains battery operated state parameter by 485 buses successively, the data analysis judgement of master control board to obtaining, when the monomer voltage value excessive, need to disconnect charge relay, when monomer voltage is too small and need to disconnect the module relay during in discharge regime and total relay, work as electric current, when surpassing certain value, temperature need to carry out alarm display, master control board also needs all voltage is compared to judgement in addition, find out the cell that voltage surpasses the certain setting value of minimum voltage, put this cell and need balanced zone bit, notify corresponding voltage acquisition plate to carry out equilibrium treatment, often through a repetition period master board, high-tension current is carried out to the primary insulation monitoring and the total voltage value of high-tension current is gathered, the magnitude of voltage obtained with the voltage acquisition plate compares, to judge the energy consumption of current wire, master control board every certain setting-up time by current working state of system parameter, in conjunction with being stored in real-time clock time in the USB storage equipment, in order to analyzed for historical data in the future.

At first whole system carries out system failure self check when operation, and fault self-checking comprises communication self check, the self check of EEPROM storage data, and fault is carried out to alarm display, when self-checking function by the time carry out normal data acquisition, transmission, calculate, fault judgement and parameter display process.

The beneficial effects of the utility model:

The master control board of battery management system of the present utility model has adopted the USB storage mode, has strengthened the readability of storage data, and the memory capacity increase, and scrapping the whole service state from dispatching from the factory to and set up corresponding data bank for the monitoring battery provides possibility.

In the utility model, adopted the method based on terminal voltage measuring and calculating insulation resistance to carry out the high-tension current insulating monitoring, wherein wire fuse is controlled and passed through to the access of high-tension current positive and negative terminal increase solid-state relay, improved the safety of system, integrated high voltage electricity global voltage measurement function, the voltage that can obtain with the voltage acquisition plate compares, and for calculating the wire energy consumption, provides method.

The utility model mesohigh voltage acquisition partly adopts the amplifier chip directly to gather, reduced the cost of whole system, the simultaneously power supply of amplifier chip controlled by solid-state relay, reduced whole system off working state from consumption of current, improved the acquisition precision of cell pressure simultaneously.

The utility model is stored the open circuit voltage under different electric currents, different temperatures and charging and discharging state under different time of repose and the relation of SOC, has improved the precision of utilizing open circuit voltage to estimate initial SOC.

The mode that in the current acquisition plate, the SOC estimation adopts coprocessor to combine with primary processor, co-processor module is to be that handling interrupt and I/O arrange specially, its speed is more fast again than primary processor, coprocessor interrupts being processed and calculate SOC now to the timer in ampere-hour integral method estimation SOC, thereby has improved the SOC estimation precision in the working process.

With Chinese patent, CN102975627A compares, the utility model proposes the USB storage, the general storage chip adopted of the storage of battery management system now, be subject to the restriction of storage size, the data of all battery management system collections that can't scrap from dispatching from the factory to vehicle are stored, electronlmobil is in development phase now, data bank is imperfection also, the USB storage space is large, speed is fast, foundation to the batteries of electric automobile data bank has great significance, for the research of electronlmobil provides Data support.

With Chinese patent CN 101141076A, compare, the utility model has adopted solid-state relay to control the power supply of amplifier chip, during in dead ship condition, cut off the power supply of amplifier chip when vehicle, thus reduced under whole battery management system off working state from consumption of current.

With Chinese patent CN 102064568A, compare, the coprocessor that this patent proposes is the unit of primary processor inside, its speed is more fast again than primary processor, and carry out data exchange by bidirectional RAM and primary processor, both are not identical concepts, the utility model utilizes coprocessor to process timer interrupt signal, has improved the estimation precision of SOC in the system work process.

In a word, the utility model provides SOC estimation in the working process of the coprocessor based on chip core.The capacity of battery also brings impact to the high precision estimation of SOC in addition, the utility model is studied as electric current, temperature, ageing state, self-discharge the influence factor of capacity of cell, utilize the relation curve correction capacity of above-mentioned parameter and capacity of cell, thereby improved the estimation precision of whole SOC.

The utility model provides a kind of cell pressure acquisition mode that adopts improved amplifier chip, with respect to traditional amplifier chip battery acquisition mode, the utility model has adopted solid-state relay to control the power supply of amplifier chip, when vehicle during in dead ship condition, cut off the power supply of amplifier chip, thereby reduced under whole battery management system off working state from consumption of current, the utility model does not adopt any switch control voltage collection in addition, has improved the acquisition precision of voltage and the reliability of system works.

The accompanying drawing explanation

The integral structure schematic diagram that Fig. 1 is battery management system of the present utility model;

Fig. 2 is amplifier chip power supply control principle drawing;

Fig. 3 is voltage signal processing circuit figure;

Wherein 1. master control boards, 2. current acquisition plate, 3. voltage acquisition plate, 4. power module I, 5. high-tension current joint, 6. power drive joint, 7. LCDs, 8. power module II, 9. current signal joint, 10. power module II, 11. voltage signal joints, 12. temperature signal joints, 13. the balancing disk joint, 14. balancing disks, 15. current sensors, 16. relay, 17. wire fuses, 18. loads.

The specific embodiment

Below in conjunction with drawings and Examples, the utility model is further elaborated, should be noted that following explanation is only in order to explain the utility model, is not limited its content.

The integral structure schematic diagram that Fig. 1 is lithium battery management system, as can be seen from Figure 1 battery management system comprises master control board, current acquisition plate, voltage acquisition plate, balancing disk and LCDs, and master control board is connected with the voltage acquisition plate, by 232 communication ports and liquid crystal display, carries out data exchange, by external devices such as CAN bus and electric vehicle instrument and entire car controllers, carries out communication with the current acquisition plate by 485 buses; The power drive joint of master control board is succeeded electrical equipment, comprising module relay, total relay, charge relay; The voltage signal joint of voltage acquisition plate connects respectively positive and negative terminal, the temperature signal joint jointing temp sensor of battery, and temperature sensor is arranged on the positive and negative terminals of battery pack, and the balancing disk joint connects balancing disk; The current signal joint of current acquisition plate connects the Hall type current sensor, and wherein current sensor is arranged on total negative terminal of high-tension current; The low pressure storage battery that the power supply of whole system adopts the 12V/24V on electronlmobil is powered to it through DC/DC isolation module separately respectively; In order to strengthen the antijamming capability of communication signal, adopt the B0505 power supply chip to be isolated the communication power supply, and adopt the 6N137 high speed photo coupling to be isolated communication signal.At first whole system carries out system failure self check when operation, and fault self-checking comprises communication self check, the self check of EEPROM storage data, and fault is carried out to alarm display, when self-checking function by the time carry out normal data acquisition, transmission, calculate, fault judgement and parameter display process.

Fig. 2 is amplifier chip power supply control principle drawing, in order to control conveniently, 8 batteries of take are now discussed as one group, 8 batteries have 9 different positive and negative terminals, through the high-temperature insulation line, be connected on the voltage signal joint of voltage acquisition plate, be respectively V1-, V1, V2, V3, V4, V5, V6, V7, V8, because number that may a Battery pack in real process may be less than 8 joints, but generally be greater than 2 joints, but in order to increase the practicality of system, voltage signal blank area signal is through receiving respectively the anode tap of diode D1-D6, the cathode terminal of diode is connected, obtain the voltage of an actual Battery pack, for reduce battery management system when the off working state from consumption of current, the voltage of the battery that obtains is connect to 8 ports of solid-state relay U1.When system starts, low tension 12V/24V produces 5V voltage through the DC/DC isolation module, 1 port of solid-state relay will become high level, this high level is connected to 2 ports through the inner LED of solid-state relay and passes through resistance R 1 ground connection again, thereby impel the internal relay conducting, pin 7 is connected with pin 8, and the voltage of battery is being powered to amplifier chip 1-8 through capacitor C 1, C2, C3, the work of feasible system; When vehicle during in dead ship condition, low tension is cut off, at this moment whole system will be in off working state, the DC/DC isolation module will not exported 5V voltage, 1 port of solid-state relay becomes low level, can not impel the internal relay conducting, pin 7 and pin 8 will be in off-states, thus while having reduced the system off working state from consumption of current.

Fig. 3 is voltage signal processing circuit figure, due to the number of a Battery pack generally between the 2-8 joint, and all voltage handling principle are similar, below to an economize on electricity, press the handling principle of signal to describe, the voltage of a general joint lithium cell is all lower than 10V, because the reference voltage of the AD sampling A/D chip adopted in the utility model is 5V, therefore need to be processed voltage signal, the anode of single battery connects the in-phase input end of op amp through resistance R 3 as shown in the figure, the negative terminal of single battery connects the reverse input end of op amp through resistance R 4, wherein the in-phase input end of amplifier chip passes through again resistance R 2 ground connection, inverting input connects mouth through resistance R 5, signal output part is through resistance R 1, capacitor C 2 connects the AD chip and gathers port, 4 of amplifier chip, 11 positive and negative feeder ear map interlinkings 2 are through capacitor C 1, capacitor C 2, cell pressure after capacitor C 3, positive feeder ear voltage is through capacitor C 1 filtering in addition, resistance R 2=resistance R 5 in circuit, it during resistance R 3=resistance R 4, is typical amplifier differential amplifier circuit.Fig. 3 has realized the high precision collecting of voltage signal in conjunction with Fig. 2, while having reduced the system off working state simultaneously from consumption of current.

Although above-mentioned, by reference to the accompanying drawings the specific embodiment of the present utility model is described; but be not the restriction to the utility model protection domain; on the basis of the technical solution of the utility model, those skilled in the art do not need to pay various modifications that creative work can make or distortion still in protection domain of the present utility model.

Claims

1. the battery management system based on coprocessor and solid-state relay, it comprises master control board and the connected current acquisition plate of difference and voltage acquisition plate, it is characterized in that, total anode and total negative terminal that described master control board connects respectively high-tension current by the high-tension current joint are realized the high-tension current insulating monitoring, by the power drive joint, succeed electrical equipment; The SOC that described current acquisition plate adopts coprocessor to be combined with primary processor and realizes battery estimates, connect current sensor by the current signal joint, described current sensor is arranged between relay and the total negative terminal of high-tension current; Described voltage acquisition plate gathers voltage signal by the amplifier chip, and the power supply of amplifier chip is controlled by solid-state relay.

2. battery management system according to claim 1, is characterized in that, described system adopts the low pressure storage battery of the 12V/24V on electronlmobil to power to it through DC/DC isolation module separately respectively; Described system adopts the B0505 power supply chip to be isolated the communication power supply, and adopts the 6N137 high speed photo coupling to be isolated communication signal.

3. battery management system according to claim 1, is characterized in that, described master control board comprises the USB memory module, for storing working status parameter.

4. battery management system according to claim 1, is characterized in that, described master control board is connected with read-out, and described read-out is LCDs, realizes the real-time demonstration to working status parameter; Described master control board is also by CAN bus and electric vehicle instrument and entire car controller communication.

5. battery management system according to claim 1, is characterized in that, described master control board also comprises power module I, main controller module I and communication module.

6. battery management system according to claim 1, it is characterized in that, described relay comprises total relay, module relay and charge relay, described total relay is connected to load, described load is connected to the total anode of high-tension current through wire fuse, described module relay is relay between battery pack, and described battery pack is the cell number that every block of voltage acquisition plate is controlled, and described charge relay connects the battery charger signal.

7. battery management system according to claim 1, is characterized in that, described current acquisition plate comprises power module II, main controller module II and current acquisition module.

8. battery management system according to claim 1, it is characterized in that, described voltage acquisition plate connects respectively the temperature sensor that is arranged on the battery pack positive and negative terminals and the positive and negative terminal of battery by temperature signal joint and voltage signal joint, described voltage acquisition plate has several, and each voltage acquisition plate corresponds to many 8 batteries.

9. battery management system according to claim 1, is characterized in that, described voltage acquisition plate is connected with balancing disk by the balancing disk joint.

10. battery management system according to claim 1, is characterized in that, described voltage acquisition plate comprises power module III, main controller module III, voltage acquisition module and temperature collection circuit.