CN202782643U - Connection circuit of power battery and motor in hybrid electric vehicle - Google Patents

Abstract

The utility model relates to a connection circuit between a power battery and a motor in a hybrid electric vehicle, which includes a motor, a motor controller provided with a pre-charging capacitor, a power battery, a strong current controller, a negative main relay, and a positive main relay and pre-charge relay. The utility model connects a delay relay between the power supply pin of the strong current controller and the ON gear power line of the automobile ignition lock. Through the delay relay, the positive and negative relays in the high-voltage circuit will not be disconnected twice within 30 seconds. Pick-up eliminates the danger of voltage rise at the motor terminal after disconnecting the circuit during motor power generation, and also solves the problem of excessive reverse current ablation of the positive and negative main relays in the circuit when the relay picks up again in a short period of time .

Description

Connection circuit between power battery and motor in hybrid electric vehicle

technical field

The utility model relates to a charging connection circuit, in particular to a connection circuit between a power battery and a motor in a hybrid electric vehicle.

Background technique

At present, in hybrid electric vehicles, there is a high-voltage power-on logic. For example, when the terminal voltage of the motor controller is pre-charged to 80% of the power battery terminal voltage, the high-voltage controller controls the positive and negative main relays. Then complete the high voltage power on.

However, during the vehicle test, ablation and adhesion of the positive and negative main relays often occurred. When analyzing the connection circuit between the power battery and the motor in the existing hybrid electric vehicle, by comparing the voltage test and comparison in the relay circuit before and after power-on, it is found that if the connection circuit between the power battery and the motor is disconnected during the power generation process of the motor, the motor will The voltage at the terminal will rise sharply. If power is turned on again in a short period of time, since the motor terminal voltage in the circuit is much greater than 80% of the power battery terminal voltage, the positive and negative main relays bypass the pre-charging and directly pull in, and the reverse current in the circuit far exceeds the maximum load of the positive and negative relays , resulting in ablation and adhesion of positive and negative relays.

purpose of invention

The purpose of this utility model is to overcome the above-mentioned deficiencies in the prior art and provide a connection circuit between the power battery and the motor in a hybrid electric vehicle. It will cause the problem of ablation and adhesion of positive and negative main relays.

The technical solution adopted to realize the purpose of this utility model is: a connection circuit between a power battery and a motor in a hybrid electric vehicle, including: a motor, a motor controller provided with a pre-charging capacitor, a power battery, and a strong current controller, The negative main relay, the positive main relay and the pre-charging relay, the three control pins of the heavy current controller are respectively connected to the normally closed contacts of the negative main relay, the positive main relay and the pre-charging relay, and it also includes: A time-delay relay, which is connected with the ON gear power line of the automobile ignition lock, and the switch of the time-delay relay is connected between the power supply pin of the described heavy current controller and the battery power line of the automobile.

Further, the delay relay is a 30-second delay relay.

The utility model adds a 30-second delay relay to the connection circuit between the power battery and the motor in the traditional hybrid electric vehicle, so that the positive and negative relays in the high-voltage circuit will not be disconnected and closed twice within 30 seconds. It eliminates the danger of the motor terminal voltage rising after the circuit is disconnected during the motor power generation process, and also solves the problem that the positive and negative main relays are ablated by excessive reverse current in the circuit when the relay is closed again in a short period of time.

Description of drawings

Fig. 1 is the connection circuit diagram of power battery to motor in existing hybrid electric vehicle;

Fig. 2 is the connection circuit diagram of power battery to motor in the hybrid electric vehicle of the present invention;

In the figure, 1-motor, 2-motor controller, 3-pre-charging capacitor, 4-negative main relay, 5-positive main relay, 6-pre-charging relay, 7-power battery, 8-pre-charging resistor, 9- Strong current controller, 10- car ignition lock ON gear power cord, 11- car battery power cord, 12-30 second delay relay.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail.

As shown in Figure 1, the existing power battery-to-motor connection circuit in a hybrid electric vehicle includes a motor 1, a motor controller 2 with a pre-charge capacitor 3, a power battery 7, a strong current controller 9, and a negative main relay 4. Positive main relay 5 and pre-charging relay 6. The power supply pin of the strong current controller 9 is connected with the ON gear power line of the automobile ignition lock. The first control pin of the strong current controller 9 is connected to the normally closed contact of the negative main relay 4, the second control pin is connected to the normally closed contact of the positive main relay 5, and the third control pin is connected to the precharge main relay 6's normally closed contact connection. The normally open contacts of the negative main relay 4 are connected to one end of the precharging capacitor 3 , and the normally open contacts of the positive main relay 5 and the precharging relay 6 are both connected to the other end of the precharging capacitor 3 .

Using the existing connection circuit above, the high-voltage power-on control process is as follows:

When the ignition lock switch is turned to the ON gear, the strong current controller 9 controls the pre-charging relay 6 and the negative main relay 4 to pull in, and the current flows to the power battery 7, the pre-charging resistor 8, the pre-charging relay 6, the pre-charging capacitor 3, Negative main relay 4, power battery 7, when the voltage U2 at both ends of the pre-charging capacitor 3 is greater than 80% of the voltage at both ends of U1, the strong current controller 9 controls the pull-in of the positive main relay 6, and disconnects the pre-charging relay 6 at the same time. Piezo power up is complete.

When the motor 1 of the car is running in the power generation condition, the current flow is the motor controller 2, the positive main relay 5, the power battery 7, the negative main relay 4, and the motor controller 2. If the car ignition lock is ON and the power line 1 is powered off In the connection circuit between the power battery 7 and the motor 1, the power supply of the high-power controller 9 is disconnected, the positive main relay 5 and the negative main relay 4 are electrically disconnected, and the voltage U2 at both ends of the pre-charging capacitor 3 in the motor controller 2 will decrease due to load dumping. It rises sharply. If the ON gear power line 1 is powered on again within 30 seconds, because the voltage U2 at both ends of the pre-charge capacitor 3 in the motor controller 2 is much greater than 80% of the power battery terminal voltage U1, the positive main relay 5 and the negative main relay 4 suction. According to I=(U2-U1)/R, because the resistance in the circuit is very small, I is very large, far exceeding the maximum load current of the positive main relay 5 and the negative main relay 4, resulting in the ablation of the positive main relay 5 and the negative main relay 4 Adhesion.

In the utility model, a 30-second delay relay 12 is connected between the power supply pin of the strong current controller and the ON gear power line 10 of the automobile ignition lock, and a 30-second delay relay 12 is connected between the power supply line 11 of the automobile battery and the power supply pin of the strong current controller. The switch control of second time delay relay 12. If the power line 1 of the ignition lock ON gear of the car loses power, because the power supply terminal of the strong current controller 9 has a delay relay of 30 seconds, the power supply of the strong current controller 9 is delayed for 30 seconds, and the positive main relay 5 and the negative main relay 4 control terminals are also Because there is electricity, the relay will be disconnected after 30 seconds after electric shock. At this time, the current in the circuit continues to flow, because the motor 1 no longer generates power, the voltage in the circuit is continuously absorbed by the power battery 7, and 30 seconds is enough to balance the voltages at both ends of the positive main relay 5 and the negative main relay 4. If the automobile ignition lock ON gear power line 1 is powered on again within 30 seconds, the positive main relay 5 and the negative main relay 4 are already in the pull-in state, which avoids the phenomenon of second disconnection and pull-in within 30 seconds. The hybrid electric vehicle power battery to the motor connection circuit based on the delay relay makes the working current of the positive main relay 5 and the negative main relay 4 return to a reasonable range, so that the service life of the positive and negative main relays is greatly increased.

Claims (2)

1. A connection circuit between a power battery and a motor in a hybrid electric vehicle, comprising: a motor, a motor controller provided with a pre-charging capacitor, a power battery, and a strong current controller, a negative main relay, a positive main relay and a pre-charging relay , the three control pins of the high current controller are respectively connected with the normally closed contacts of the negative main relay, the positive main relay and the pre-charging relay, it is characterized in that, also includes: A time-delay relay, which is connected with the ON gear power line of the automobile ignition lock, and the switch of the time-delay relay is connected between the power supply pin of the described heavy current controller and the battery power line of the automobile. 2. The connection circuit between the power battery and the motor in the hybrid electric vehicle according to claim 1, characterized in that: the delay relay is a 30-second delay relay.

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