Battery heat preservation system and its control method under a kind of low-temperature environment of electric vehicleTechnical field
It is electric under specifically a kind of low-temperature environment of electric vehicle the present invention relates to a kind of battery heat preservation system and its control methodPond heat-insulation system and its control method.
Background technique
As the power battery of one of electric car core technology, performance directly affects the performance of electric car, occupiesVery important status.
If power battery is placed under low temperature environment for a long time, the destruction of inside battery structure, capacity attenuation, service life drop will causeIt is low, the course continuation mileage of electric car is greatly reduced, or even start electric car can not, has seriously affected pushing away for electric carWide application.Traditional battery thermal management system, it is main to focus on opening under the heat dissipation of battery and low temperature environment when electric car is runInterim heating when dynamic, and the lasting heat preservation being placed under low temperature environment for a long time for battery does not have research, therefore how rightBattery under low temperature environment is placed in for a long time to carry out continuing the problem of heat preservation is industry urgent need to resolve.
Summary of the invention
In view of the above existing problems in the prior art, the present invention provides battery thermal systems under a kind of low-temperature environment of electric vehicleSystem and its control method, can be heated and be kept the temperature to the battery last under low temperature environment, be in greatly shorten battery packThe time of low temperature environment extends the service life of battery pack.
To achieve the goals above, the technical solution adopted by the present invention is that: battery is protected under a kind of low-temperature environment of electric vehicleWarm system, including heat exchange box, controller, start switch, protective switch, limit temperature/heat-insulation switch, insulation indicator lamp, heating instructionLamp, Electrocontrolled tee valve, electric heater, circulation power source and temperature-detecting device,
Battery pack is arranged in heat exchange box, and two ports of Electrocontrolled tee valve pass through the stream of heat transfer pipe and heat exchange box respectivelyOutlet is connected to the inlet port of electric heater, and the outflux of electric heater is connected by heat transfer pipe and the inlet port in circulation power sourceLogical, the outflux in circulation power source is connected to by heat transfer pipe with the inlet port of heat exchange box；In the heat exchange box and heat transfer pipeIt is filled with heat transfer medium；
The battery pack, start switch, protective switch, limit temperature/heat-insulation switch and electric heater be sequentially connected in series forming circuit,Protective switch is normally closed switch, and starting switch and limit temperature/heat-insulation switch is normal open switch；Insulation indicator lamp series connection one current limliting electricityIt is connected in parallel on limit temperature/heat-insulation switch both ends after resistance R1, is connected in parallel on electric heater after one current-limiting resistance R2 of heating lamp series connectionBoth ends, wherein current-limiting resistance R1 is equal with the resistance value of current-limiting resistance R2；
The controller respectively with temperature-detecting device, start switch, protective switch and limit temperature/heat-insulation switch connects, electricPond group is controller, Electrocontrolled tee valve, electric heater and the power supply of circulation power source.
Further, the circulation power source is circulation pump or fan.
Further, the battery pack is that multisection lithium battery forms in series and parallel.
Further, the temperature-detecting device is made of temperature sensor a, temperature sensor b and temperature sensor c, temperatureThe outside of heat exchange box is arranged in degree sensor a, is used for real-time monitoring environment temperature；Temperature sensor b is arranged in battery surface,For real-time monitoring battery pack temperature；Temperature sensor c setting is used for real-time monitoring heat transfer medium temperature on heat transfer pipe surfaceDegree.
Further, the heat transfer medium is water or air or conduction oil.
Further, insulating layer is enclosed with outside the heat transfer pipe.
The control method of battery heat preservation system, specific steps under a kind of low-temperature environment of electric vehicle are as follows:
I, the value of minimum temperature T1 and the value of maximum temperature T2 are first set, is then stored in controller；
II, controller detects the working condition of onboard system first, if onboard system is in non-working condition, controllerControl starts switch closure, controller real-time reception temperature-detecting device transmits at this time ambient temperature value, battery pack temperature valueWith heat-transfer medium temperature value；
III, since environment temperature and heat-transfer medium temperature seriously affect the efficiency of battery pack heat preservation, when environment temperature is unexpectedWhen variation, the heat that heat transfer medium is transmitted to battery pack can great changes will take place.In addition when heat-insulation system works, electric heaterThere are hesitations to the process that battery pack keeps the temperature battery pack for the heat transfer of generation, it is therefore desirable to utilize environment temperature, electricityPond group temperature and heat-transfer medium temperature predict battery pack future temperature；Ambient temperature value that controller will test, batteryGroup temperature value and heat-transfer medium temperature value carry out real-time analytical calculation, to obtain battery pack predicting temperature values T；Detailed processAre as follows: first to environment temperature, battery pack temperature and the heat-transfer medium temperature information detected using known neural network algorithm intoRow screening analysis, establishes battery pack temperature historical information, so that it is pre- to establish the battery pack temperature based on known neural network algorithmSurvey model；Battery pack predicting temperature values can be predicted by the model；When controller runs the prediction model, the prediction modelBy real-time detection to ambient temperature value, battery pack temperature value and heat-transfer medium temperature value merge, to estimate batteryThe temperature value of group subsequent time, i.e. battery pack predicting temperature values T；
IV, controller compares the battery pack predicting temperature values T being calculated and minimum temperature T1 and maximum temperature T2Right, if battery pack predicting temperature values T is lower than minimum temperature T1, controller control limit temperature/heat-insulation switch is closed, at this time battery packStart electric heater with power P for electric heater power supply1Work, while controller control loop power source is opened, and makes to conduct heatMedium is moved in circles between electric heater and battery pack by heat transfer pipe, to begin to warm up to battery pack, heatedHeating lamp is in illuminating state in journey, since insulation indicator lamp is connected in parallel on limit temperature/heat-insulation switch both ends, when limit temperature/heat preservationWhen switch is in closure, insulation indicator lamp is short-circuited in non-lit up state at this time；When the battery pack that controller is calculated is pre-When thermometric angle value T is greater than maximum temperature T2, controller control limit temperature/heat-insulation switch is disconnected, at this time insulation indicator lamp and current limliting electricityResistance R1 is connected into circuit, since current-limiting resistance R1 is much larger than the internal resistance of electric heater, can reduce the electric current in circuit and then makeElectric heater is with power P2Work, i.e. power P2Much smaller than power P1, while circulation power source is still opened, and battery pack is enteredKeeping warm mode, since heating lamp lights required point light current greater than the electric current in the circuit after current limliting, heating refers toShow that lamp is in non-lit up state, insulation indicator lamp is in illuminating state；
If V, the battery pack real-time temperature values that controller receives be greater than maximum temperature T2 continue for some time after (this whenBetween it is related with heating power and the maximum temperature T2 of setting), then controller control protective switch disconnect, to cut off electric heaterWith the connection status of battery pack, heating lamp and insulation indicator lamp are in non-lit up state at this time.
Compared with prior art, the present invention using heat exchange box, controller, start switch, protective switch, limit temperature/heat preservation openPass, insulation indicator lamp, heating lamp, Electrocontrolled tee valve, electric heater, circulation power source and the temperature-detecting device side of combiningFormula heats the heat transfer medium for flowing through electric heater by opening electric heater under low-temperature environment, then by followingRing power source drive heat transfer medium is moved in circles between electric heater and heat exchange box by heat transfer pipe, and heat transfer medium is enteringHeat exchange is carried out with battery pack after heat exchange box, since the higher temperature at this time of heat-transfer medium temperature can pass to heat exchange from heat transfer mediumBattery pack in case, the heat transfer medium for then completing heat exchange reenters electric heater and is heated, to hold to battery packIt is continuous to be heated；Therefore the present invention can be heated and be kept the temperature to the battery last under low temperature environment, to greatly shorten batteryGroup is in the time of low temperature environment, extends the service life of battery pack.
Detailed description of the invention
Fig. 1 is the electrical schematic diagram of the present invention with battery pack；
Fig. 2 is structural schematic diagram of the invention；
Fig. 3 is control flow chart of the invention；
Fig. 4 is the calculation flow chart of battery pack predicting temperature values in the present invention.
In figure: 101- heat-insulation system；102- battery pack；103- onboard system；201- heat transfer pipe；202- is started switch；203- protective switch；204- limits temperature/heat-insulation switch；205- controller；206- insulation indicator lamp；207- heating lamp；208-Electrocontrolled tee valve；209- electric heater；210- circulation power source；211- temperature sensor a；212- temperature sensor b；213- temperatureSpend sensor c.
Specific embodiment
The present invention will be further described below.
As shown, battery heat preservation system under a kind of low-temperature environment of electric vehicle, including heat exchange box, controller 205, startingSwitch 202, protective switch 203, limit temperature/heat-insulation switch 204, insulation indicator lamp 206, heating lamp 207, Electrocontrolled tee valve208, electric heater 209, circulation power source 210 and temperature-detecting device,
Battery pack 102 be arranged in heat exchange box, two ports of Electrocontrolled tee valve 208 pass through respectively heat transfer pipe 201 withThe outflux of heat exchange box is connected to the inlet port of electric heater 209, the outflux of electric heater 209 by heat transfer pipe 201 withThe inlet port in circulation power source 210 is connected to, and the outflux in circulation power source 210 passes through the entrance of heat transfer pipe 201 and heat exchange boxMouth connection；Heat transfer medium is filled in the heat exchange box and heat transfer pipe 201；
The battery pack 102, start switch 202, protective switch 203, limit temperature/heat-insulation switch 204 and electric heater 209 according toSecondary series connection forming circuit, protective switch 203 are normally closed switch, and starting switch 202 and limiting temperature/heat-insulation switch 204 is normally opened openIt closes；Limit temperature/heat-insulation switch 204 both ends, heating lamp 207 are connected in parallel on after one current-limiting resistance R1 of the series connection of insulation indicator lamp 206It connects and is connected in parallel on the both ends of electric heater 209 after a current-limiting resistance R2, wherein the resistance value phase of current-limiting resistance R1 and current-limiting resistance R2Deng；
The controller 205 respectively with temperature-detecting device, start switch 202, protective switch 203 and limit temperature/heat preservation open204 connections are closed, battery pack 102 is that controller 205, Electrocontrolled tee valve 208, electric heater 209 and circulation power source 210 power.
Further, the circulation power source 210 is circulation pump or fan.It is dynamic according to the property of heat transfer medium and required circulationThe on-demand optimum selecting of the size of power.
Further, the battery pack 102 is that multisection lithium battery forms in series and parallel.This structure is adding battery pack 102It is heated more evenly when hot.
Further, the temperature-detecting device is by temperature sensor a211, temperature sensor b212 and temperature sensorThe outside of heat exchange box is arranged in c213 composition, temperature sensor a211, is used for real-time monitoring environment temperature；Temperature sensor b212Setting is used for 102 temperature of real-time monitoring battery pack on 102 surface of battery pack；Temperature sensor c213 is arranged in heat transfer pipe 201Surface is used for real-time monitoring heat-transfer medium temperature.
Further, the heat transfer medium is water or air or conduction oil.Three kinds of heat transfer mediums are low according to locating for battery pack 102The minimum temperature of warm environment, on-demand optimum selecting.
Further, insulating layer is enclosed with outside the heat transfer pipe 201.Setting insulating layer can reduce heat transfer medium in pipelineIt is exchanged with the heat of external environment, reduces the thermal loss in heat transfer medium transmission process, improved the heating to battery pack 102 and imitateRate.
The control method of battery heat preservation system, specific steps under a kind of low-temperature environment of electric vehicle are as follows:
I, the value of minimum temperature T1 and the value of maximum temperature T2 are first set, is then stored in controller 205；
II, controller 205 detects the working condition of onboard system first, if to be in non-working condition (vehicle-mounted for onboard systemSystem itself can generate heat at work and can heat to battery pack 102, work without electric heater 209), then it controlsDevice 205 processed control starts switch 202 closures, 205 real-time reception temperature-detecting device of controller transmits at this time ambient temperature value,Battery pack temperature value and heat-transfer medium temperature value；
III, since environment temperature and heat-transfer medium temperature seriously affect the efficiency of the heat preservation of battery pack 102, when environment temperature is prominentSo when variation, the heat that heat transfer medium is transmitted to battery pack 102 can great changes will take place.In addition when heat-insulation system works, electricityThere are hesitations to the process that battery pack 102 keeps the temperature battery pack 102 for the heat transfer that heater 209 generates, it is therefore desirable to102 temperature of battery pack is predicted using environment temperature, battery pack temperature and heat-transfer medium temperature；Controller 205 will testAmbient temperature value, battery pack temperature value and heat-transfer medium temperature value carry out real-time analytical calculation, to obtain battery pack predictionTemperature value T；Detailed process are as follows: first to environment temperature, battery pack temperature and the heat-transfer medium temperature information detected usingKnow that neural network algorithm carries out screening analysis, establish battery pack temperature historical information, is calculated to establish based on known neural networkThe battery pack temperature prediction model of method；Battery pack predicting temperature values can be predicted by the model；When controller runs the predictionWhen model, the prediction model by real-time detection to ambient temperature value, battery pack temperature value and heat-transfer medium temperature value meltIt closes, thus estimate the temperature value of battery pack subsequent time, i.e. battery pack predicting temperature values T；
IV, controller 205 carries out the battery pack predicting temperature values T being calculated and minimum temperature T1 and maximum temperature T2It compares, if battery pack predicting temperature values T is lower than minimum temperature T1, the control limit temperature/heat-insulation switch 204 of controller 205 is closed, thisWhen battery pack 102 be electric heater 209 power supply make electric heater 209 start with power P1Work, while the control of controller 205 followsRing power source 210 is opened, and recycles heat transfer medium between electric heater 209 and battery pack 102 by heat transfer pipe 201 pastMultiple, to begin to warm up to battery pack 102, heating lamp 207 is in illuminating state during heating, since heat preservation indicatesLamp 206 is connected in parallel on limit temperature/204 both ends of heat-insulation switch, when limiting temperature/heat-insulation switch 204 and being in closure, insulation indicator lamp at this time206 are short-circuited in non-lit up state；When the battery pack predicting temperature values T that controller 205 is calculated is greater than maximum temperature T2When, the control limit temperature/heat-insulation switch 204 of controller 205 disconnects, and insulation indicator lamp 206 and current-limiting resistance R1 are connected into circuit at this time, byIn current-limiting resistance R1 be much larger than electric heater 209 internal resistance, therefore can reduce the electric current in circuit so that make electric heater 209 withPower P2Work, i.e. power P2Much smaller than power P1, while circulation power source 210 is still opened, and battery pack 102 is made to enter heat preservationState, since heating lamp 207 lights required point light current greater than the electric current in the circuit after current limliting, heating instructionLamp 207 is in non-lit up state, and insulation indicator lamp 206 is in illuminating state；
If V, the battery pack real-time temperature values that controller 205 receives are greater than after maximum temperature T2 is continued for some time and (are somebody's turn to doTime is related with heating power and the maximum temperature T2 of setting), then controller 205 controls protective switch 203 and disconnects, to cut offThe connection status of electric heater 209 and battery pack 102, heating lamp 207 and insulation indicator lamp 206 are in non-lit up at this timeState.