Direct-current charger starting self-checking device

Abstract

The utility model discloses a direct current charger starting self-checking device which comprises a main control module, a current sampling module, an insulation detection module, a discharge loop, a short circuit detection module, a voltage sampling module, a reverse connection detection module, a first relay, a second relay and a third relay. The main control module controls each detection and sampling module and the relay to start self-inspection according to a charging process, receives detection data uploaded by each module, compares the detection data with a set threshold value, and starts corresponding alarm or charging according to a comparison result, so that on the basis of insulation resistance detection, interface connection detection and vehicle terminal voltage detection, the detection efficiency is improved. Outer side voltage detection of the first relay and the second relay, direct current output end short circuit detection and battery reverse connection detection are added before insulation resistance detection, a communication protocol of the charger and a battery management system is not affected, the accident occurrence probability in the charging process is effectively reduced, and the safety of the charger is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of charging, and in particular relates to a starting self-checking device for a direct current charger. Background Art

[0002] With the rapid development of new energy technology and the intensification of the global energy crisis, the demand for electric vehicles using clean energy is increasing, and the demand for supporting chargers is also increasing. During the charging process, the charger has high voltage and high current transmission, which requires high safety of the charging circuit; and the charging environment is complex and changeable, with many external interference factors. During the charging stage of the charger, due to the circuit characteristics of the charger, the instantaneous high current output is prone to contact sparks, arcing and other phenomena, which will bring huge safety hazards to the charging process. If the charger and the entire charging circuit can be checked before the charger starts charging, it will effectively reduce the safety hazards during the charging process.

[0003] The existing charger self-test technology mainly performs insulation resistance detection, interface connection detection, and vehicle terminal voltage detection in accordance with the provisions of B.3.3 and B.3.4 of GB / T18487.1-2015. The test items are not comprehensive enough to fully cover the faults in actual use, especially the DC output short circuit caused by improper operation, equipment aging, etc., and the battery reverse connection and other faults are not detected. Utility Model Content

[0004] In order to solve the above problems, the utility model provides a DC charger startup self-test device, which can add the first relay and the second relay outer side voltage detection, DC output terminal short circuit detection, and battery reverse connection detection before insulation resistance detection on the basis of insulation resistance detection, interface connection detection, and vehicle terminal voltage detection, without affecting the communication protocol between the charger and the battery management system.

[0005] The technical solution adopted by the utility model to solve its technical problems is: a DC charger startup self-test device, which includes: a main control module, a current sampling module, an insulation detection module, a discharge circuit, a short circuit detection module, a voltage sampling module, a reverse connection detection module, a first relay, a second relay and a third relay, wherein the current sampling module is connected in series to the DC output positive line of the charger, the discharge circuit and the third relay are connected in series and then connected in parallel between the positive and negative outputs of the charger, the insulation detection module is connected in parallel between the positive and negative outputs of the charger, the sampling points of the voltage sampling module are the positive and negative outputs of the charger and the positive and negative outputs of the first and second relays, the sampling points of the reverse connection detection module are the positive and negative outputs of the first and second relays, the short circuit detection module is connected in series to the normally open end of the first relay, and the current sampling module, the insulation detection module, the short circuit detection module, the voltage sampling module, the reverse connection detection module, the first relay, the second relay and the third relay all communicate with the main control module.

[0006] Furthermore, the main control module controls the current sampling module, insulation detection module, short circuit detection module, voltage sampling module, reverse connection detection module, first relay, second relay, and third relay to start self-inspection according to the charging process and receive the detection data uploaded by each module, compares the detection data with the set threshold, and starts a corresponding alarm or starts charging according to the comparison result.

[0007] Furthermore, the current sampling module can collect the DC output current of the charger, the insulation detection module can perform insulation detection on the charging circuit, the discharge circuit can perform voltage discharge after insulation detection, the short circuit detection module can detect whether there is a short circuit condition in the charging output circuit, the voltage sampling module can collect the voltages of the normally closed end and the normally open end of the first relay and the second relay, and the reverse connection detection module can detect whether there is a battery reverse connection condition at the normally open end of the first relay and the second relay.

[0008] The implementation of the DC charger startup self-test device of the utility model has the following beneficial effects:

[0009] 1. On the basis of conventional self-test items, the first relay, the second relay outer voltage detection, DC output short circuit detection, and battery reverse connection detection are added. The self-test items cover a wider range and do not affect the communication protocol between the charger and the battery management system;

[0010] 2. Performing a comprehensive self-check on the charger before charging can effectively reduce the probability of accidents during the charging process and improve the safety of the charger. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The utility model is a block diagram of a DC charger startup self-checking device. DETAILED DESCRIPTION

[0012] The technical solution of the utility model is further explained below in conjunction with the accompanying drawings.

[0013] like Figure 1 As shown, a DC charger startup self-test device includes a main control module, a current sampling module, an insulation detection module, a discharge circuit, a short circuit detection module, a voltage sampling module, a reverse connection detection module, a first relay K1, a second relay K2 and a third relay K3.

[0014] The current sampling module is connected in series to the positive DC output line of the charger. The discharge circuit and the third relay K3 are connected in series and then connected in parallel between the positive and negative outputs of the charger. The insulation detection module is connected in parallel between the positive and negative outputs of the charger. The sampling points of the voltage sampling module are the positive and negative outputs of the charger and the positive and negative outputs of the first relay K1 and the second relay K2. The sampling points of the reverse connection detection module are the positive and negative outputs of the first relay K1 and the second relay K2. The short-circuit detection module is connected in series to the normally open end of the first relay K1. The current sampling module, insulation detection module, short-circuit detection module, voltage sampling module, reverse connection detection module, first relay K1, second relay K2, and third relay K3 all communicate with the main control module.

[0015] The main control module controls the current sampling module, insulation detection module, short circuit detection module, voltage sampling module, reverse connection detection module, the first relay K1, the second relay K2, and the third relay K3 to start self-inspection according to the charging process and receive the detection data uploaded by each module, compares the detection data with the set threshold, and activates the corresponding alarm or starts charging according to the comparison result.

[0016] The current sampling module can collect the DC output current of the charger, the insulation detection module can perform insulation detection on the charging circuit, the discharge circuit can discharge the voltage after insulation detection, the short circuit detection module can detect whether there is a short circuit in the charging output circuit, the voltage sampling module can collect the voltage of the normally closed end and the normally open end of the first relay K1 and the second relay K2, and the reverse connection detection module can detect whether there is a battery reverse connection condition at the normally open end of the first relay K1 and the second relay K2.

[0017] After starting the charger, the main control module confirms that the charging gun is connected. After the battery management system is powered on, it performs handshake communication with the main control module of the charger. After the handshake is completed, the main control module controls the voltage sampling module to detect the voltage outside K1 and K2. If the voltage outside K1 and K2 is greater than 10V, charging is not allowed and a fault is reported. If the voltage outside K1 and K2 is less than or equal to 10V, the main control module controls K1 and K2 to close. After K1 and K2 are closed, the short-circuit detection module is started to perform short-circuit detection. If the short-circuit detection fails, charging is not allowed and a fault is reported. If the short-circuit detection is qualified, the main control module controls the insulation detection module to work and perform insulation detection. The insulation detection includes symmetrical and asymmetrical insulation detection. If the insulation detection fails, charging is not allowed and a fault is reported. If the insulation detection is qualified, the main control module controls K3 to close and cut in. The discharge circuit discharges the insulation detection voltage. After the voltage discharge is completed, the main control module sends a periodic message to the battery management system. The main control module controls the reverse connection detection module to perform reverse connection detection. If there is a reverse voltage in the reverse connection detection, charging is not allowed and a fault is reported. If the reverse connection detection is qualified, the main control module controls the voltage sampling module to detect the battery terminal voltage. If the battery terminal voltage is abnormal, charging is not allowed and a fault is reported. If the battery terminal voltage meets the battery voltage error range of the communication message ≤±5%, and is greater than the minimum output voltage of the charger and less than the maximum output voltage of the charger, the main control module controls the charger to start pre-charging. After starting pre-charging, the main control module controls the voltage sampling module to detect the front and rear voltages of K1 and K2 in real time. When the voltage difference between the two ends is 1V~10V, K1 and K2 are closed to start charging.

[0018] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from them are still within the scope of protection of the present utility model.

Claims

1. A DC charger startup self-test device, which include: A main control module, a current sampling module, an insulation detection module, a discharge circuit, a short circuit detection module, a voltage sampling module, a reverse connection detection module, a first relay, a second relay and a third relay, characterized in that the current sampling module is connected in series to the DC output positive line of the charger, the discharge circuit and the third relay are connected in series and then in parallel between the positive and negative outputs of the charger, the insulation detection module is connected in parallel between the positive and negative outputs of the charger, the sampling points of the voltage sampling module are the positive and negative outputs of the charger and the positive and negative outputs of the first and second relays, the sampling points of the reverse connection detection module are the positive and negative outputs of the first and second relays, the short circuit detection module is connected in series to the normally open end of the first relay, and the current sampling module, the insulation detection module, the short circuit detection module, the voltage sampling module, the reverse connection detection module, the first relay, the second relay and the third relay all communicate with the main control module.

2. A DC charger startup self-test device according to claim 1, It is characterized in that The main control module controls the current sampling module, insulation detection module, short circuit detection module, voltage sampling module, reverse connection detection module, first relay, second relay and third relay to start self-check according to the charging process and receive the detection data uploaded by each module, compares the detection data with the set threshold, and starts corresponding alarm or starts charging according to the comparison result.

3. A DC charger startup self-test device according to claim 1, It is characterized in that The current sampling module can collect the DC output current of the charger, the insulation detection module can perform insulation detection on the charging circuit, the discharge circuit can discharge the voltage after the insulation detection, the short circuit detection module can detect whether there is a short circuit condition in the charging output circuit, the voltage sampling module can collect the voltages of the normally closed end and the normally open end of the first relay and the second relay, and the reverse connection detection module can detect whether there is a battery reverse connection condition at the normally open ends of the first relay and the second relay.

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