Shenzhen Hongjiali New Energy Co.Ltd
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After sale telephone: 14774839877
Address: No. 412, Chang Feng Road, Baoan District, Shenzhen, Guangdong.
In the charging process of electric vehicle charging pile charger, when people do not remove the plug, the battery is always charged. For this reason, it often leads to the phenomenon of overcharging or uncharging of the battery. The life of the battery is closely related to the charging method of the battery. The battery needs about 5~8 h per charge time (according to the difference in the power consumption of the battery). After the charger is charged (the charger indicator light shows the green light), the battery will recharge the 1~3 H (according to the depth of the electricity consumption before the battery is charged), it is necessary to recharge the charging time. The charger must be removed, otherwise the battery will overcharge. Due to the limitation of the above charging conditions, it is difficult to achieve ideal control of charging power at night or at work. Therefore, how to control the charging effect of battery has attracted people's attention.
Several practical models invented by the State Patent Office have been published, but they all fail to meet the battery charging technology requirements. The full automatic overvoltage, overcharge and electric vehicle battery charging protector can make the charger cut off immediately when the charger is "completed" and solve the problem of overcharging of the battery. The disadvantage is that the charger has just changed into the completion state to cut off the power supply, the battery has no floating charge process and the battery can not be repaired, which does not conform to the charging technical requirements of the battery. In addition, the charger shell is also disassembled to use the wiring as its own control signal plug, which also violates the relevant principles of the use of the goods, and can not be an independent and complete product extension; the electric vehicle charging protection socket can disconnect the battery charging power when the charger is charged, but it is short of the float of the battery. It does not conform to the charging technology requirements of the battery; the overcharge protector of the electric car battery can make the delay of the battery after the floating charge, and its defect is that the floating charge time can not be regulated, that is, it can not be used according to the amount of electricity consumption before the charge of the battery, which often causes the overcharge of the battery. It happened.
It can be seen that the charger of electric vehicle can not be automatically broken down, it is difficult to rely on the manual control of the power supply, and there are some defects in the public invention devices. For this reason, the electric vehicle battery can not avoid the phenomenon of undercharging or overcharging, which affects the normal life and also causes the social power resources. The waste of the family and the economic loss of the family.
To sum up, electric vehicle charger has defects that can not be automatically cut off, and the method of manual control is difficult to meet the requirements of charging technology. The invention and application of "control signal source without lead electric vehicle charging timely interruption protector" is a more reasonable and effective method to assist the battery charging.
2 the invention and effect verification of the timely power cut protector
2.1 technical scheme
The charging pile auxiliary charger provides automatic power break function to make up for the defects of the charger itself which can not be cut off. It provides a floating charge function for the charger after charging, and makes the battery have a repair process; it can provide the corresponding floating charge time according to the different power consumption of the battery before charging, and provide more appropriate charging time for the battery; The means of obtaining the control signal from the charger not open the charger casing from the charger inside the charger, so that the ordinary electric vehicle users can be used directly; the whole device adopts the plug and socket insertion and miniaturization to facilitate the user's use.
The internal circuit of the 2.2 circuit group cost device mainly consists of sampling circuit, gate control circuit, delay circuit, electronic switch circuit, relay and its driving circuit, power failure indicator circuit, and the circuit block diagram is shown in Figure 1.
2.3 circuit principle
The schematic diagram of the circuit is shown in Figure 2.
The sampling circuit uses a diode D2 as the component. The charge pile charger produces a pressure drop at different output voltages at different stages of the charger as the signal source, and sends the control circuit through the resistance. The gate control circuit consists of a unidirectional silicon controlled DT and a tri transistor BG1. The thyristor control pole acts as the input end of the gate control. The control signal is received. The pressure drop produced by the large current at the two ends of the sampling diode before the charger "charging" is made through the controlled silicon, and the output voltage jump of the charger "charging" is reduced. At both ends of the sampling diode, the instantaneous reverse voltage pulse is produced to stop the silicon controlled silicon. The pressure drop of the small current at both ends of the diode after the "charging completion" can not make the silicon controlled. The triode collector is the output of the gate control circuit, and the anode potential of the thyristor is inverted. The output terminal potential of the gate control circuit controls the charge and discharge state of the capacitor in the delay circuit. When the thyristor is connected, the anode is low potential, the gate control circuit outputs high potential and the capacitance of the delay circuit is charged. The longer the capacitor charging time is, the higher the positive electrode potential of the capacitor is (not more than the gate control output potential). When the silicon controlled silicon cut-off, the anode is high potential, the gate control output is low potential, the capacitor discharge state, and the electric discharge state. The higher the positive electrode potential, the longer the discharge time, and through the adjustment of the parameters of the component, the maximum discharge time and the proportion of charge and discharge time required by the compound can be obtained. The voltage of the positive electrode potential in the delay circuit can be used to control the switching of the electronic switch. The electronic switch is mainly composed of an insulated gate field effect tube BG2, and the leakage pole of the field effect tube is the output end of the electronic switch. The output potential of the electronic switch is related to the anode potential of the silicon controlled silicon control, but the output potential of the electronic switch is related to its own connection, and the connection of the electronic switch is controlled by the capacitor positive electrode potential in the delay circuit. High and low, high potential when the capacitor positive pole is high, the field effect tube is connected, the output of the electronic switch is low potential, the discharge of the capacitor positive pole is low, the field effect tube cut-off, the electronic switch output is high potential, the high and low control relay of the electronic switch output potential and its driving circuit are connected. The relay J and its driving circuit are divided into the front stage amplifier and the last stage amplifier. The forward stage magnification is composed of a composite tube. The off state is controlled by the output terminal potential of the electronic switch. The last stage amplifier is mainly composed of the middle power triode. Its connection is controlled by the forward stage amplifier, the action of the relay J is controlled and the electronic switch is lost. When the end is low potential, the relay and its driving circuit cut-off, the relay does not move, the relay constant contact J1 is connected with the transfer contact J3, the battery charging circuit is closed; when the electronic switch output is high potential, the relay and its driving circuit are connected, the relay action, the relay's constant contact J1 and the transfer contact J3 break off. Open, normally open contact J2 and switch contact J3 are closed, battery charging circuit opens, power off indication circuit and power negative pole form loop, indicating lamp is bright. The auxiliary charger of the utility model realizes the ideal working process of the final charging of the battery to the floating charge at different time after the "charging completion", and the final power off.
2.4 effect test method
2.4.1 sample model
There are 5 kinds of power failure protectors made of three different functions, namely:
A power break protector that automatically adjusts the floating charge time according to the different initial capacity of the battery; a power break protector with a floating charge time limit of 2 h; a power break protector with no floating charge function immediately when the charger is turned to the green light.
2.4.2 experiment object and start time
In March 2011, a full capacity test was carried out for the electric vehicle of the same type of electric vehicle in the same dormitory and 20 households in the same dormitory, and three kinds of different functional samples were sent to 15 of the electric vehicles.
2.4.3 test method and time
In December 2012, the above 20 electric vehicle batteries were tested respectively.
3.1 comparison of test results
(1) the foot capacity of the battery is compared with the results of one and a half years ago. The battery test results of 5 electric vehicles using a floating charge automatically adjusted power break protector have reduced the capacity of the foot by about 20%.
(2) the battery test results of 5 electric vehicles using 2 h floating charge protectors have a capacity drop of about 35%..
(3) the battery test results of 5 electric vehicles using the power fail protector without floating charging function were compared with the test results two years ago, and the capacity of the batteries was reduced by about 50%.
(4) compared with the test results of two years ago, the battery test results of the 5 electric vehicles without floating charging protectors have decreased by 60% or more.
Analysis of 3.2 test results
The test results show that the model of the 20 electric vehicles, the initial capacity, the time of use and the mileage of the vehicle are all the same, and the attenuation speed of the battery capacity is obviously different. It is proved that the service life of the battery is closely related to the charging method of the battery. The control of the floating charge time after the charger is completed affects the service life of the battery.