The control method of battery pack temperature control system and corresponding battery pack temperatureTechnical field
The present invention relates to vehicular field, relate generally to a kind of control system, particularly relate to a kind of battery pack temperature control system.The invention still further relates to the control method of corresponding battery pack temperature.
Technical background
Along with the development of science and technology and the progress of society, automobile has become the vehicles important in people's daily life, along with the sale of vehicle increases year by year, vehicle energy consumption also constantly increases, thing followed energy resource consumption also becomes current important topic, and the petroleum-based energy of automobile burning consumption faces exhaustion already, therefore in order to energy-saving and emission-reduction, a lot of vehicle manufacturers power research and development electric automobile all at present, namely by the power source of lithium battery as vehicle.And due to the accumulation of heat can be produced in lithium battery power supply process, just likely cause power system failure, even initiation fire once accumulation of heat to certain degree, vehicle and occupant are caused serious injury.Meanwhile, the power brick due to vehicle use is combined by multiple battery cell, and therefore, during vehicle launch, power brick temperature is too low, or it is too large to there is the temperature difference during vehicle operating between each battery pack, all can cause the life time decay of power brick.
In order to avoid the generation of above-mentioned situation, Temperature-controlled appliance must be equipped with to battery pack, to ensure that battery pack reaches best runnability and useful life.A kind of temperature control system to battery is there is in prior art, the temperature of power brick can be controlled in a rational scope, but need the energy of consumption larger during the work of this temperature control system, and system works generally has battery pack to provide electric energy, and the life-span of battery pack is limited, namely the charge and discharge circulation life of battery is fixing, utilizes battery set charge/discharge to carry out operating temperature control system, can shorten the life-span of battery itself.
Power to not use battery itself, a kind of temperature control system utilizing solar cell for supplying power is provided in prior art, definite meaning can reduce the use to the battery of vehicle own, but the cost of solar cell is high, and utilize the temperature control system of solar cell to make System's composition more complicated, add the possibility of global failure, and run into rainy weather, solar energy just cannot work, and just needs to utilize other system to carry out collaborative work, to the control of battery temperature with regard to inaccuracy.
In addition, the control device of different temperature control systems is also different, such as, there is a kind of control device to battery temperature in prior art, this control device is then difference testing environment temperature and battery temperature, then the threshold value of battery temperature and ambient temperature is had in control system storage inside, make corresponding control according to detected temperatures to the comparison result of storage threshold, the shortcoming of this control method is thermometric more single, is not very accurate for control.And in order to make control more accurate, more existing control device controls by comparing to the threshold value stored in the mean value of battery pack and control system, there is shortcoming in this control mode: first equally, do not come to a conclusion in the current industry of setting of the threshold point of battery temperature; Secondly, although this control device has certain effect, but mean temperature can not reflect the temperature conditions of each batteries monomer, because each batteries monomer is in individual difference, therefore in cell operation, the temperature of each battery cell also there are differences, if certain battery cell is higher than other battery cell temperature, because the temperature of battery raises, reaction speed is accelerated, and battery cell temperature often raises 1 DEG C, and failure rate increase is about 7%, temperature often raises 10 DEG C, and its catagen speed just increases by 1 times.And the life-span of battery pack exactly depends on the battery cell arriving end of life the earliest, the battery cell that namely catagen speed is the fastest, therefore, the catagen speed of whole battery pack also can increase thereupon.
In addition, in existing control system, the cooling system of battery and heating system are separated, so not only make System's composition more huge, control more complicated, the failure rate of simultaneity factor also can significantly improve.
Summary of the invention
The technical problem to be solved in the present invention, be to provide a kind of battery pack temperature control system, cooling and heating system are rolled into one by it, can measure in real time the temperature of battery pack during vehicle operating, and adjust according to the temperature of program to battery pack self stored, ensure that battery pack is in best running status, extend the useful life of battery pack;
Another object of the present invention, is to provide a kind of control system method of battery pack temperature.
For achieving the above object, the technical solution adopted in the present invention is:
A kind of battery pack temperature control system, based on the control of heat exchanging medium temperature, comprising:
Control unit, storage inside has the highest threshold value with minimum temperature difference of the threshold value of the threshold value of battery cell mean temperature, battery pack temperature value peak, battery pack temperature minimum point threshold value, battery pack temperature, and calculates alignment programs;
Detecting unit, for detecting the temperature value of battery pack each point in real time, and the temperature value of detection is real-time transmitted to control unit, control unit finds out the temperature value at the thermal self-restraint stress place of detected battery pack, the temperature value at temperature minimum point place in the temperature information received, and calculate the difference of the temperature value at thermal self-restraint stress place and the temperature value at temperature minimum point place, and the average temperature value of battery pack;
Performance element, for controlling heat exchange medium temperature and flow, after the numerical value calculated and the threshold value that goes out to store in it are compared by control unit, send control signal to performance element by changing the flow of heat transferring medium and temperature and then controlling the temperature of battery pack.
As limitation of the invention: described detecting unit comprises at least four temperature sensors, be located at the water inlet that heat transferring medium flows into battery pack for one in temperature sensor, be located at the water outlet that heat transferring medium flows out battery pack for one, remaining is distributed in battery pack.
Limit as to another kind of the present invention: described performance element comprises under the control of the control unit, for controlling the water pump of heat transferring medium flow, and under the control of the control unit, for controlling the heater of heat exchange medium temperature, described water pump is provided with full gear and middle speed gear; Heater is located on the pipeline between water pump and battery pack.
A control method for battery pack temperature, comprises the following steps:
One, collecting temperature information: gathered the temperature value of battery pack difference respectively by detecting unit, flowed into the temperature value of the heat transferring medium of battery pack, and the temperature value of the heat transferring medium of outflow battery pack;
Two, control unit makes corresponding control: each temperature value in the step one of reception is carried out calculating comparison according to the program himself stored by control unit, control actuator afterwards to be adjusted by the temperature of heat exchanging medium, and then control the temperature of battery pack.
Restriction as to above-mentioned control method: described step 2 comprises the following steps
(1) the maximum temperature value T of battery pack in temperature information is found outhand lowest temperature angle value Tl;
(2) the maximum temperature value T obtained in calculation procedure ()hwith lowest temperature angle value Tldifference △ T, and the threshold value stored in △ T and control unit to be compared;
(3) the mean temperature T-of all battery cells is calculatedave, and by mean temperature T-avecompare with the threshold value stored in control unit;
(4) control unit makes corresponding control according to the comparison result in step (two), (three).
Further restriction as to said method: the control that in described step (four), control unit is made comprises the following steps:
(1) judge the magnitude relationship of △ T and 6 DEG C, if △ T≤6 DEG C, perform step (2), otherwise perform step (3);
(2) T-is judgedavewith the magnitude relationship of 25 DEG C, if T-ave+>=25 DEG C then perform steps A, namely judge Thwith the magnitude relationship of the threshold value set in control unit; Otherwise perform step B, namely judge Tlwith the magnitude relationship of the threshold value set in main control unit;
(3) judge the magnitude relationship of △ T and 10 DEG C, if △ T >=10 DEG C, there is catastrophe failure in control unit alarm, and continue 5s alarm condition, independently disconnected the contactor in major loop by BMS simultaneously; Otherwise control unit is to sending fault-signal to control unit for vehicle, alarm driver carries out maintenance work simultaneously.
Further restriction as to said method: described steps A comprises the following steps:
(a1) T is judgedhwith the magnitude relationship of 50 DEG C, if Th>=50 DEG C then control unit control to report to the police and follow-up power down process etc., otherwise perform step (a2);
(a2) T is judgedhwith the magnitude relationship of 40 DEG C, if Th>=40 DEG C then control unit control water pump and open full gear, increase the flow of heat transferring medium and battery cooled, otherwise perform step (a3);
(a3) T is judgedhwith the magnitude relationship of 35 DEG C, if Th>=35 DEG C then control unit control water pump open in speed gear, the flow suitably increasing heat transferring medium cools battery, otherwise system gets back to step one.
Limit as to the another kind of said method: described step B comprises the following steps:
(b1) T is judgedlwith the magnitude relationship of-10 DEG C, if Tl≤-10 DEG C then control unit carry out reporting to the police and follow-up power down process etc., otherwise perform step (b2);
(b2) T is judgedlwith the magnitude relationship of 0 DEG C, if Tl≤ 0 DEG C then control unit control starting mode of pump full gear, control heater heat exchanging medium heats simultaneously, and then increases the temperature of battery pack, otherwise performs step (b3);
(b3) T is judgedlwith the magnitude relationship of 15 DEG C, if Tl≤ 15 DEG C then control unit control water pump open in Soviet Union's gear, simultaneously control heater heat exchanging medium heats, and then suitably increases the temperature of battery pack, otherwise water pump stall, and heater stops heating, gets back to step one.
The present invention, owing to adopting above technical scheme, can reach following technique effect:
(1) battery pack temperature control system of the present invention, by the temperature sensor of detecting unit two import department and exits be located at heat transferring medium and flowed into and flow out battery pack wherein, remaining is distributed in battery pack, therefore the temperature of the battery cell of battery pack diverse location can be detected, and the temperature value of battery pack maximum temperature point can be drawn, the temperature value of minimum temperature point, the difference of maximum temperature point and minimum temperature point, and the average temperature value of battery pack, after the threshold value that temperature value obtained above is corresponding with each temperature value above-mentioned stored in control unit is compared, control unit just can make control to actuator, and then accurately can control the temperature of battery pack,
(2) the present invention is to the control of battery pack temperature, realized by the control of heat exchanging medium temperature, and battery pack temperature control system of the present invention not only can carry out cooling control by the flow increasing heat transferring medium to battery pack, simultaneously can by heating heat transferring medium, and the flow increasing heat transferring medium completes and controls the intensification of battery pack, namely a system can complete and heat up to battery pack, the control of cooling, System's composition is simple, failure rate is low, and the electric energy of not consuming cells group, therefore the optimum performance of battery pack can be ensured, extend the useful life of battery pack.
In sum, battery pack temperature control system of the present invention forms simple, can ensure the optimum performance of battery and extend the useful life of battery pack.
Battery pack temperature control system of the present invention and control method are applicable to various motor vehicle, are used for controlling the temperature of battery pack.
Accompanying drawing explanation
Fig. 1 is the theory diagram of the embodiment of the present invention;
Fig. 2 is the flow chart of the embodiment of the present invention to vehicle operating modes control method.
In figure: 1-control unit, 2-detecting unit, 3-tank for coolant, 4-water pump, 5-heater, 6-battery pack.
Embodiment
embodimentthe control method of a kind of battery pack temperature control system and corresponding battery pack temperature
I, a temperature control system for battery pack, it is formed as shown in Figure 1, comprising:
Control unit 1, control unit storage inside in the present embodiment has the threshold value of the threshold value of the threshold value of the mean temperature of battery pack, battery pack temperature value peak, battery pack temperature minimum point threshold value, battery pack temperature peak and temperature minimum point difference, and calculate, alignment programs, described calculating, alignment programs are already present programs in prior art, can directly use.
Detecting unit 2, for detecting the temperature value of each temperature detecting point of battery pack in real time, and by detect temperature value be real-time transmitted to control unit.The present embodiment adopts temperature sensor as detecting unit 2, and at least four temperature sensors are installed, during layout, a temperature sensor is located at the water inlet that heat transferring medium flows into battery pack, the water outlet that heat transferring medium flows out battery pack is located at by a temperature sensor, remaining temperature sensor is distributed in battery pack (more accurate in order to control, a temperature sensor can be all set to each battery cell, and the heat transferring medium of the present embodiment adopts freezing liquid).
The temperature value detected is real-time transmitted to control unit by the temperature sensor in the present embodiment, the temperature value that the thermal self-restraint stress that the program that control unit utilizes self to store can find out detected battery pack in the temperature information received goes out, the temperature value at temperature minimum point place, and the program computation utilizing self to store goes out the difference of the temperature value at temperature value that thermal self-restraint stress goes out and temperature minimum point place, and the average temperature value of battery pack.
Performance element, for controlled cooling model liquid temp and flow, the present embodiment comprises water pump 4 and heater 5, and wherein water pump 4 is provided with full gear and middle speed gear, and it can be located in the container of splendid attire cooling fluid, namely in tank for coolant 3, control, after the numerical value calculated and the threshold value that goes out to store in it are compared by control unit, to send control signal, the control signal sent according to control unit 1 and select closedown, or open full gear or middle speed gear, and then change the flow of cooling fluid; On the pipeline of heater 5 between water pump and battery pack, open or close according to the control of control unit, to performance element for changing the temperature of cooling fluid.By the change to coolant rate and temperature, and then change the temperature of battery pack group.
II, a control method for battery pack temperature, is realized by aforesaid battery pack temperature control system.As shown in Figure 2, this control method comprises the following steps:
One, collecting temperature information: gathered the temperature value of the different battery cell of battery pack respectively by detecting unit, flowed into the temperature value of the cooling fluid of battery pack, and the temperature value of the cooling fluid of outflow battery pack;
Two, control unit makes corresponding control: each temperature value in the step one of reception is carried out calculating comparison according to the program himself stored by control unit, controls actuator afterwards by adjusting the temperature of cooling fluid, and then controls the temperature of battery pack.Comprise the following steps:
(1) the maximum temperature value T of battery pack in temperature information is found outhand lowest temperature angle value Tl;
(2) the maximum temperature value T obtained in calculation procedure ()hwith lowest temperature angle value Tldifference △ T, and the threshold value stored in △ T and control unit to be compared;
(3) the mean temperature T-of all battery cells is calculatedave, and by mean temperature T-ave+compare with the threshold value stored in control unit;
(4) control unit makes corresponding control according to the comparison result in step (two), (three), and concrete control comprises the following steps:
(1) judge the magnitude relationship of △ T and 6 DEG C, if △ T≤6 DEG C, perform step (2), otherwise perform step (3).
(2) T-is judgedavewith the magnitude relationship of 25 DEG C, if
1. T-ave>=25 DEG C then perform following steps A, judge Thwith the magnitude relationship of the threshold value set in control unit, steps A comprises the following steps (a1) ~ (a3):
(a1) T is judgedhwith the magnitude relationship of 50 DEG C, if Th>=50 DEG C of then control unit control warnings, (such power operation needs and full-vehicle control device co-controlling the contactor that simultaneity factor is independently disconnected in major loop by BMS, because different vehicle-states is as climbing etc., direct power-off can produce danger such as slipping by slope), otherwise perform step (a2);
(a2) T is judgedhwith the magnitude relationship of 40 DEG C, if Th>=40 DEG C then control unit control water pump and open full gear, increase the flow of cooling fluid and battery cooled, otherwise perform step (a3);
(a3) T is judgedhwith the magnitude relationship of 35 DEG C, if Th>=35 DEG C then control unit control water pump open in speed gear, the flow suitably increasing cooling fluid cools battery, otherwise system gets back to step one.
2. T-ave>=25 DEG C, then perform step B, namely judge Tlwith the magnitude relationship of the threshold value set in main control unit; Step B comprises the following steps (b1) ~ and (b3):
(b1) T is judgedlwith the magnitude relationship of-10 DEG C, if Tl≤-10 DEG C then control unit report to the police, (such power operation needs and full-vehicle control device co-controlling the contactor that simultaneity factor is independently disconnected in major loop by BMS, because different vehicle-states is as climbing etc., direct power-off can produce danger such as slipping by slope), otherwise perform step (b2);
(b2) T is judgedlwith the magnitude relationship of 0 DEG C, if Tl≤ 0 DEG C then control unit control starting mode of pump full gear, control heater heats cooling fluid simultaneously, and then increases the temperature of battery pack, otherwise performs step (b3);
(b3) T is judgedlwith the magnitude relationship of 15 DEG C, if Tl≤ 15 DEG C then control unit control water pump open in Soviet Union's gear, simultaneously control heater heats cooling fluid, and then suitably increases the temperature of battery pack, otherwise water pump stall, and heater stops heating, gets back to step one.
(3) magnitude relationship of △ T and 10 DEG C is judged, if △ T >=10 DEG C, there is catastrophe failure in control unit alarm, and continue 5s alarm condition, (such power operation needs and full-vehicle control device co-controlling the contactor that simultaneity factor is independently disconnected in major loop by BMS, because different vehicle-states is as climbing etc., direct power-off can produce danger such as slipping by slope); Otherwise control unit is to sending fault-signal to control unit for vehicle, alarm driver carries out maintenance work simultaneously.
The battery pack temperature control system of the present embodiment forms simple, and failure rate is low, the temperature value simultaneously owing to detecting is more, and the control for battery temperature is also more accurate, effectively can ensure serviceability and the useful life of battery.