CN105691223B - Charging device capable of automatically identifying charging voltage of electric automobile by charger - Google Patents

Abstract

A charger automatically identifies the charging voltage of an electric automobile, which relates to the technical field of electric automobiles and provides low power voltage for communication devices of the electric automobile, if the communication devices of the electric automobile are detected not to obtain enough power voltage, the power voltage supplied to the communication devices of the electric automobile is increased, and the electric automobile is charged until the communication devices of the electric automobile are detected to obtain enough power voltage, wherein the low power voltage is not higher than the lowest power voltage in the power voltages required by the communication devices of various electric automobiles matched with the charger, because the charger can automatically identify whether the voltage initially supplied to the electric automobile is enough, if not enough, the voltage supplied to the electric automobile can be automatically increased, the same set of charger can charge the electric automobiles with different voltage requirements, the risk of burning out the circuit of the battery management system of the automobile is avoided, the system construction cost is reduced, and the utilization rate of the charger is improved.

Description

A charging device for a charger to automatically identify the charging voltage of an electric vehicle

technical field

The invention relates to the technical field of electric vehicles, in particular to a charging method for a charger to automatically identify the charging voltage of an electric vehicle. The method is completed by establishing a functional module framework and controlling a computer system by computer program instructions. These computer program instructions are stored in the computer. on readable storage media.

Background technique

At present, electric vehicles have been widely developed, especially electric buses have been given priority in some cities and regions. In order to facilitate the charging of electric vehicles, charging stations have been established in various places. The current charging process is that the vehicle plug of the charger control device first provides low-voltage auxiliary power to the battery management system (BMS) of the electric vehicle through the vehicle socket of the electric vehicle, and the BMS can only establish with the control system of the charger control device after obtaining normal power supply. Correct communication, after the communication is established, the charger control device can provide the corresponding voltage and current according to the requirements of the BMS.

The identification definition of each contact of the electric vehicle DC charging device connector stipulated in the national standard GB/T 20234.3 is shown in Figure 1. The charger control device has a detection point 1 on the connection line of the contact CC1, which is used for the charger control device. Confirm whether the vehicle plug of the charger and the vehicle socket of the electric vehicle are connected normally. If the connection is normal, the charger control device supplies power to the BMS through the contacts A+ and A-, and the electric vehicle passes the detection point on the connection line of the contact CC2 2 Detect the voltage at this point, so as to judge whether the vehicle socket of the electric vehicle and the vehicle plug of the charger are connected normally. If the connection is normal, an identification message will be sent to the charger control device. Send an identification message.

At present, due to technical and standard reasons, the BMS of small passenger cars such as electric cars uses a 12V power supply system, and the BMS of buses such as electric buses uses a 24V power supply system. When charging electric vehicles with different BMS supply voltages, it is necessary to use a charging system with a corresponding output voltage. If the electric bus uses a low-voltage auxiliary power supply to charge a 12V charger, the communication cannot be established due to the insufficient power supply of the BMS, and charging cannot be performed. . If a small passenger car uses a low-voltage auxiliary power supply to charge a 24V charger, the circuit will work abnormally or even burn out because the BMS power supply is too high.

In order to avoid the above problems, the charging stations serving two types of vehicles should build two different chargers, and at the same time, it should be marked which ones are suitable for charging electric cars (BMS is a 12V power supply system) and which ones are suitable for charging electric buses (BMS is a 24V power supply system) power supply system), and also indicate that electric cars and electric buses cannot mix chargers. This increases the construction cost and reduces the utilization rate of the equipment, and there is also the risk of burning the BMS circuit of the car by misuse.

Contents of the invention

The purpose of the present invention is to avoid the deficiencies in the prior art and provide a charging method and a charging device for a charger to automatically identify the charging voltage of an electric vehicle. The charging method for the charger to automatically identify the charging voltage of an electric vehicle can make the same charging The machine can charge electric vehicles with different voltage requirements.

The object of the present invention is achieved through the following technical solutions:

Provide a charging method for a charger to automatically identify the charging voltage of an electric vehicle, and provide a low power supply voltage to the communication device of the electric vehicle. The power supply voltage of the electric vehicle will be charged until it is detected that the communication devices of the electric vehicle have obtained sufficient power supply voltage. The lowest power supply voltage among the required power supply voltages.

Among them, whether the communication device of the electric vehicle has obtained enough power supply voltage is confirmed by whether the identification message sent by the communication device is received, and if the communication signal sent by the communication device is not received, it is judged by detecting the voltage of the contact CC2 Either the communication device is faulty or the communication device does not get enough power supply voltage.

Wherein, a voltage detection circuit is provided at the contact CC2 of the charging plug of the charger to detect the voltage of the contact CC2.

Wherein, if the voltage of the contact CC2 is greater than the maximum point value of the first voltage range, it is judged that the communication device is faulty; if the voltage of the contact CC2 is smaller than the minimum point value of the first voltage range, it is judged that the communication device is not Sufficient power supply voltage needs to increase the power supply voltage of communication devices supplied to electric vehicles.

Wherein, the first voltage range is not less than 5.2V and not more than 6.8V.

Wherein, the communication device is a battery management system of an electric vehicle, and the communication signal is an identification message.

Among them, the auxiliary power supply with adjustable output voltage is used to increase the power supply voltage supplied to the communication devices of the electric vehicle.

Among them, the supply of low power supply voltage to the communication device of the electric vehicle is performed after confirming that the charger and the electric vehicle are fully connected.

Among them, confirming that the charger is fully connected to the electric vehicle is by detecting that the voltage of the contact CC1 of the charging plug of the charger meets the requirements.

Wherein, the low power supply voltage is equal to the lowest power supply voltage among the power supply voltages required by various electric vehicle communication devices adapted to the charger.

Beneficial effects of the present invention:

A charging method of the present invention for a charger to automatically identify the charging voltage of an electric vehicle, which provides a low power supply voltage to the communication device of the electric vehicle, and if it is detected that the communication device of the electric vehicle has not obtained sufficient power supply voltage, then the power supply voltage is increased to supply the electric vehicle The power supply voltage of the communication device until it is detected that the communication device of the electric vehicle has obtained a sufficient power supply voltage, then the electric vehicle is charged, and the low power supply voltage is not higher than that of various electric vehicles that are compatible with this charger The lowest power supply voltage among the power supply voltages required by communication devices. Since the charger can automatically identify whether the initial voltage supplied to the electric vehicle is sufficient, if it is not enough, it will automatically increase the voltage supplied to the electric vehicle. Therefore, the same set of The charger can charge electric vehicles with different voltage requirements. For example, it can charge electric cars and electric buses, avoiding the failure of low-voltage chargers to supply power to the battery management system of high-voltage electric vehicles or high-voltage chargers for low-voltage electric vehicles. The risk of burning the circuit of the battery management system of the car due to the power supply of the battery management system of the car reduces the cost of system construction and improves the utilization rate of the charger.

Description of drawings

Utilize accompanying drawing to further illustrate the invention, but the embodiment in the accompanying drawing does not constitute any limitation to the present invention, for those of ordinary skill in the art, under the premise of not paying creative work, can also obtain other according to following accompanying drawing Attached picture.

Figure 1 is a diagram of the identification definition of each contact of the electric vehicle DC charging device connector specified in the national standard GB/T 20234.3.

Fig. 2 is a schematic circuit diagram of the low-voltage auxiliary power supply of the present invention.

Fig. 3 is a schematic flow chart of the method of the present invention.

detailed description

The present invention is further described in conjunction with the following examples.

In this embodiment, a charging method for a charger to automatically identify the charging voltage of an electric vehicle. Figure 1 shows the identification definitions of the contacts of the electric vehicle DC charging device connector specified in the national standard GB/T 20234.3. This figure is cited for convenience only. The implementation process of this embodiment will be described.

The low-voltage auxiliary power supply of this embodiment is shown in Figure 2, including the input terminal Input, the output terminal Output and the control terminal Con, the output terminal is connected to the low-voltage auxiliary power supply port of the charging gun of the charger, and the control terminal is connected to the charger control device. The auxiliary power supply can set the output voltage at 12V or 24V.

Preferably, the low-voltage auxiliary power supply includes a voltage detection circuit and a current detection circuit, the sampling signals of the voltage detection circuit and the current detection circuit are sent to the charger control device, the voltage detection circuit is used to detect the voltage of detection point 1 and detection point 2, and the current detection The circuit is used to detect whether the output current of the low-voltage auxiliary power supply is normal.

As shown in Figures 1 to 3, when the vehicle plug of the charger is connected to the vehicle socket of the electric vehicle, the voltage at detection point 1 will rise to 4V. And the vehicle socket of the electric car is fully connected. Then the charger control device will close the relays K3 and K4 to provide low-voltage auxiliary power to the battery management system of the electric vehicle (in the vehicle control device of the electric vehicle, hereinafter referred to as BMS). The current charger control device, if it is a charging device designed for electric cars, will provide 12V auxiliary power for BMS; if it is a charging device designed for electric buses, it will provide 24V auxiliary power for BMS, and the power supply voltage cannot Change according to actual needs.

The low-voltage auxiliary power system in this embodiment is shown in Figure 2. When the charger control device confirms that the connection between the vehicle plug of the charger and the vehicle socket of the electric vehicle is completed, the low-voltage auxiliary power supply will provide 12V auxiliary power to the BMS through relays K3 and K4. Power supply, the detailed flow chart is shown in Figure 3. Preferably, a current detection circuit may be provided in the low-voltage auxiliary power supply, and when the current detection circuit detects that the output current of the low-voltage auxiliary power supply is abnormal, the low-voltage auxiliary power supply is turned off.

If the vehicle being charged is an electric car, 12V can meet the needs of the BMS, and the BMS will start to work. After U2 powered by the BMS circuit receives a 12V voltage supply, the voltage at detection point 2 (the second detection point) will rise to about 6V After the BMS detects that the voltage of the detection point 2 has risen to about 6V, it will periodically send "identification messages" to the charger control device. After receiving the signal, the charger control device confirms that the communication has been established, and then the charger control The device controls the charger to charge the battery pack of the electric vehicle (via contacts DC+ and DC-).

The BMS power supply of the electric vehicle to be charged is an electric bus with 24V. Since the voltage provided by the low-voltage auxiliary power supply is 12V, the U2 voltage of the BMS system of the electric vehicle is insufficient, and the connection confirmation cannot be completed, and the BMS will not send the "identification message". ". If the charger control device confirms that the vehicle plug of the charger is connected to the vehicle socket of the electric vehicle and has not received the "identification message" for a period of time, it is considered that the BMS power supply voltage may be insufficient, and then through the voltage detection circuit at the detection point 2 Detecting that the voltage of the CC2 port is much lower than 6V, the charger control device controls the low-voltage auxiliary power supply to gradually increase the output voltage, and at the same time monitors whether the output current of the low-voltage auxiliary power supply is abnormal, and turns off the low-voltage auxiliary power supply if abnormal.

If the output voltage of the low-voltage auxiliary power supply increases to 24V, and at the same time, the voltage at the CC2 terminal is detected to increase to 6V by the voltage detection circuit at detection point 2, it means that the BMS of the electric vehicle to be charged is a 24V system. After the BMS power supply is normal, it will start to send "identification messages". After receiving the "identification message", the charger control device confirms that the communication has been established, and the charger can start charging the battery pack of the electric vehicle (through the contacts DC+ and DC-).

In this embodiment, a charging method for a charger to automatically identify the charging voltage of an electric vehicle provides a low power supply voltage for the communication device of the electric vehicle. The power supply voltage of the communication device of the car, until it is detected that the communication device of the electric car has obtained a sufficient power supply voltage, then the electric car is charged. The lowest power supply voltage among the power supply voltages required by communication devices. Since the charger can automatically identify whether the initial voltage supplied to the electric vehicle is sufficient, if it is not enough, it will automatically increase the voltage supplied to the electric vehicle. Therefore, it can make the same A set of chargers, which can charge electric vehicles with different voltage requirements, such as charging electric cars and electric buses, avoiding that the low-voltage charger cannot supply power for the battery management system of high-voltage electric vehicles or the high-voltage charger is for low-voltage. The risk of burning the circuit of the battery management system of the car due to the power supply of the battery management system of the electric vehicle reduces the system construction cost and improves the utilization rate of the charger.

In this embodiment, a charging method for a charger to automatically identify the charging voltage of an electric vehicle is completed by establishing a functional module framework and controlling a computer system by computer program instructions, and these computer program instructions are stored in a computer-readable storage medium.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than limiting the protection scope of the present invention, although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand , the technical solution of the present invention may be modified or equivalently replaced without departing from the spirit and scope of the technical solution of the present invention.

Claims (9)

1. A charging device for a charger that automatically recognizes the charging voltage of an electric vehicle, is characterized in that it is used to provide a low power supply voltage to the communication device of the electric vehicle, if it is detected that the communication device of the electric vehicle has not obtained enough power supply voltage, then Increase the power supply voltage of the communication device supplied to the electric vehicle until it is detected that the communication device of the electric vehicle has obtained sufficient power supply voltage, and then charge the electric vehicle. The lowest power supply voltage among the power supply voltages required by the communication devices of electric vehicles; Whether the communication device of the electric vehicle has received sufficient power supply voltage is confirmed by whether the identification message sent by the communication device is received. Either the device is malfunctioning or the communication device is not getting enough supply voltage. 2. A charging device for a charger to automatically identify the charging voltage of an electric vehicle as claimed in claim 1, wherein a voltage detection circuit is provided at the contact CC2 of the charging plug of the charger to detect the voltage of the contact CC2. Voltage. 3. A charging device for a charger to automatically identify the charging voltage of an electric vehicle as claimed in claim 1, characterized in that: if the voltage of the contact CC2 is greater than the maximum point value of the first voltage range, it is judged that the communication device is faulty , if the voltage of the contact CC2 is less than the minimum point value of the first voltage range, it is judged that the communication device has not obtained enough power supply voltage, and the power supply voltage for the communication device of the electric vehicle needs to be increased. 4. A charging device for a charger to automatically identify the charging voltage of an electric vehicle according to claim 3, wherein the first voltage range is not less than 5.2V and not greater than 6.8V. 5. A charging device for a charger to automatically identify the charging voltage of an electric vehicle as claimed in claim 1, wherein the communication device is a battery management system of the electric vehicle, and the communication signal is an identification message. 6. A charging device for a charger to automatically identify the charging voltage of an electric vehicle as claimed in claim 1 or 5, characterized in that: the power supply voltage supplied to the communication device of the electric vehicle is increased by an auxiliary power supply with adjustable output voltage. 7. A charging device for a charger to automatically identify the charging voltage of an electric vehicle as claimed in claim 1, wherein the low power supply voltage is provided to the communication device of the electric vehicle after confirming that the charger is fully connected to the electric vehicle implemented. 8. A charging device for a charger to automatically identify the charging voltage of an electric vehicle as claimed in claim 7, characterized in that: confirming that the charger is fully connected to the electric vehicle is by detecting the voltage of the contact CC1 of the charging plug of the charger meet the requirements. 9. A charging device for a charger that automatically recognizes the charging voltage of an electric vehicle as claimed in claim 1, wherein the low power supply voltage is equal to that required by the communication devices of various electric vehicles that are compatible with the charger. The lowest power supply voltage among the power supply voltages.