KR100456842B1 - Ev & hev short detection system between high voltage line and vehicle chassis - Google Patents

Abstract

The present invention relates to a short circuit detection system of an electric vehicle that detects a contact resistance between a high voltage line of a vehicle and a vehicle body and checks it in advance to prevent a problem caused by a short circuit and to perform maintenance immediately when a short circuit occurs. . The present invention provides a system for detecting a short circuit state between a high voltage line and a vehicle body of an electric vehicle, the system comprising: a power supply unit supplying power to the electric vehicle; A short circuit detection unit connected to an electric circuit between the vehicle body of the electric vehicle and a power supply line (+,-) to detect a contact resistance between the high voltage line of the electric vehicle and the vehicle body; A control unit (ECU) which analyzes signals input through the short detection unit and determines a short state according to a change in an output voltage between a vehicle body and a power supply unit of the electric vehicle; And a display unit configured to receive and display data determined by the controller ECU.

Description

Short circuit detection system of electric vehicle {EV & HEV SHORT DETECTION SYSTEM BETWEEN HIGH VOLTAGE LINE AND VEHICLE CHASSIS}

The present invention relates to an electric vehicle, and more particularly to a short circuit detection system of an electric vehicle.

Typically, electric vehicles and hybrid electric vehicles use high voltage for sufficient use of energy because they use electric energy as the main power source.

In addition, a line for supplying power from a battery, which is an energy storage medium, to a motor controller, an air conditioner controller, and a heater controller, which are energy use media, is connected by a high voltage wire.

However, there may be a problem caused by the method related to the insulation coating of the connection wire harness (W / H) or a problem in the insulation at each controller portion to short-circuit the high voltage line in the vehicle body.

Here, the problems occurring when the high voltage line is in contact with the vehicle body will be described.

First, when the positive line of the high voltage line is short-circuited to the body, an electric shock may occur when a person touches the body.

In addition, when there is even a slight contact, the amount of charge is continuously reduced to shorten the vehicle mileage.

In addition, this can cause problems for vehicle electronics systems powered by 12V power.

When the negative line is shorted to the body, it is not as dangerous as the positive line, but it may cause problems in the vehicle electrical system, and high currents may flow into the contacted areas, causing sparks and deterioration.

Currently, electric vehicles have been applied in consideration of safety issues related to electric shock, and thus, strengthen the insulation of high voltage lines, use special specifications of a connector, and isolate high voltage lines.

It is anticipated that various applications will be applied to increase the stability. However, since electric vehicles are not mass-produced, it is impossible to confirm which method to use.

An object of the present invention is to detect a contact resistance between the high-voltage line and the vehicle body of the electric vehicle to check it in advance to prevent in advance the problem caused by a short circuit and to provide a short circuit detection system of the electric vehicle that can be immediately repaired when a short circuit occurs. To provide.

1 is a block diagram of a short circuit detection circuit of a high voltage line and a vehicle body for an electric vehicle and a hybrid electric vehicle according to an embodiment of the present invention.

In order to achieve the above object, the present invention provides a system for detecting a short circuit state between a high voltage line and a vehicle body of an electric vehicle, comprising: a power supply unit for supplying power of the electric vehicle; A short circuit detection unit connected to an electric circuit between the vehicle body of the electric vehicle and a power supply line (+,-) to detect a contact resistance between the high voltage line of the electric vehicle and the vehicle body; A control unit (ECU) which analyzes signals input through the short detection unit and determines a short state according to a change in an output voltage between a vehicle body and a power supply unit of the electric vehicle; And a display unit configured to receive and display data determined by the controller ECU.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. While many specific details, such as the following description and the annexed drawings, are shown to provide a more general understanding of the invention, these specific details are illustrated for the purpose of explanation of the invention and are not meant to limit the invention thereto. And a detailed description of known functions and configurations that may unnecessarily obscure the subject matter of the present invention will be omitted.

A system configuration for detecting a short circuit between a high voltage line and a vehicle body of an electric vehicle according to an exemplary embodiment of the present invention will be described with reference to FIG. 1.

An embodiment of the present invention includes a power supply unit 110, a short circuit detection unit 120, a control unit (ECU) 130, and a display unit (Cluster Display) 140.

The power supply unit 110 is a main battery that supplies power of an electric vehicle.

Electric vehicles use voltages around 250-350V as their primary energy storage medium, while hybrid electric vehicles use voltages around 80-150V as their secondary energy storage medium.

The short circuit detection unit 120 is connected to an electric circuit between the vehicle body of the electric vehicle and the power supply unit 110 lines (+,-) to detect a contact resistance between the high voltage line and the vehicle body of the electric vehicle.

As illustrated in FIG. 1, the short circuit detection unit 120 includes two voltage distribution capacitors 122 (Cd) and two voltage measurement capacitors 124 and 126 (Cm; Cm1 and Cm2).

First, the two voltage distribution capacitors 122 (Cd) are connected in parallel with the power supply 110 and distribute the voltage of the power supply 110.

The two voltage measuring capacitors 124 and 126 (Cm; Cm1, Cm2), that is, the first voltage measuring capacitor 124 (Cm1) and the second voltage measuring capacitor 126 (Cm2) It is connected in series between the voltage distribution capacitor 122 (Cd) to measure the voltage of the power supply unit 110 by voltage distribution.

Here, the value of the voltage distribution capacitor 122 (Cd) is configured to be larger than the value of the voltage measurement capacitors 124, 126 (Cm; Cm1, Cm2).

For example, the value of the voltage distribution capacitor 122 (Cd) should be about 100 times or more than the value of the voltage measurement capacitors 124 and 126 (Cm; Cm1, Cm2).

On the other hand, it should be noted that the voltage output from the voltage measuring capacitors 124 and 126 (Cm; Cm1 and Cm2) is output as a voltage of "Cm / (Cm + Cd)" times.

The controller (ECU) 130 analyzes the signals input through the short circuit detection unit 120 to determine a short circuit condition according to the output voltage change between the vehicle body of the electric vehicle and the power supply unit 110.

Here, the control unit (ECU) 130 refers to the microcontroller (Microcontroller) shown in FIG.

In addition, the control unit (ECU) 130 according to an embodiment of the present invention is a control unit that detects a state of the current power supply unit 110, rather than installing an additional control unit in a vehicle, rather than a conventional battery management system (BMS). Note that it can be used efficiently by adding functions to the Motor Control Unit (MCU) and Electronic Timing and Alarm Control System (ETACS).

The display unit 140 receives and displays the determined data from the control unit ECU 130.

The embodiment of the present invention further includes a conversion unit 150 connected to an electrical circuit between the short detection unit 120 and the control unit ECU 130 to amplify and convert the voltage of the short detection unit 120. do.

The converter 150 includes an analog / digital converter 152 (AD converter) and a unit gain amplifier 154 (Voltage Follower).

First, the analog-to-digital converter 152 (AD Converter) digitalizes the voltage supplied to the voltage measuring capacitors 124 and 126 (Cm; Cm1 and Cm2) to a signal to the controller (ECU) 130. It serves to supply.

The unit gain amplifier 154 (Voltage Follower) is connected to an electrical circuit between the voltage measuring capacitors 124 and 126 (Cm; Cm1 and Cm2) and the analog / digital converter 152 (AD Converter) to measure voltage. The voltages measured by the capacitors 124 and 126 (Cm; Cm1 and Cm2) are insulated.

That is, there is a risk of system malfunction when the voltage measured by the voltage measuring capacitors 124 and 126 (Cm; Cm1 and Cm2) is directly supplied to the analog / digital converter 152 (AD Converter). For this purpose, a voltage is sent to the analog / digital converter 152 (AD Converter) through a unit gain amplifier (154).

In the above configuration, the control unit ECU 130 reads the values of the first and second voltage measuring capacitors 124 and 126 (Cm; Cm1 and Cm2), and compares the values. If the absolute values of the second voltage measuring capacitors 124 and 126 (Cm; Cm1 and Cm2) are the same and are equal to half the value of the power supply unit 110 within the set error range, it is determined that the short circuit state is good.

If the value of the first voltage measuring capacitor 124 (Cm1) is greater than or equal to the set value, the controller (ECU) 130 determines that the short circuit and the dielectric breakdown are in progress in the negative (-) line of the power supply 110. do.

On the contrary, the control unit ECU 130 may short-circuit and break down the anode line of the power supply unit 110 if the value of the second voltage measuring capacitor 126 (Cm2) is greater than or equal to the set value. To judge.

Meanwhile, an embodiment of the present invention further includes a CAN interface 160 and a log in out interface 170.

The CAN interface 160 transmits an information signal regarding whether the power supply unit 110 is short-circuited and insulation breakdown is supplied from the control unit ECU 130 to other control units in the vehicle.

The log in out interface 170 functions to receive and transmit a signal for a high voltage line blocking command or a warning command of an electric vehicle and other systems for checking and operating the electric vehicle.

As described above, the embodiment of the present invention detects the contact resistance (normal state infinity) between the high-voltage line and the vehicle body of the electric vehicle and checks it in advance, and the human body shock, system instability, system down due to a short circuit. Etc. can be prevented beforehand.

That is, in the embodiment of the present invention, a plurality of capacitors are installed between the vehicle body and the power supply 110 line (+,-), and these voltages are detected to use the change to change the capacitor voltage when a partial or complete short circuit occurs. The short circuit status of the main power line and the car body can be checked as follows.

1. It is possible to check the short circuit between the body and the high voltage line.

2. For maintenance, you can check the shorted line among the power supply unit 110 (+,-) lines.

3. It is possible to detect the possibility of short circuit when line deterioration and breakdown are in progress.

4. The cluster can display the need for maintenance.

5. Short circuit information can be sent to other control units.

As described above, the short-circuit detection system of the electric vehicle according to the present invention can increase the stability of the vehicle and can prevent the vehicle running performance from falling by reducing the power consumption caused by the short-circuit.

In addition, when a vehicle problem occurs, it is possible to improve serviceability by indicating a maintenance pointer and to reduce costs by using an existing control unit without installing an additional control unit.

Claims (11)

delete delete In a system for detecting a short circuit condition between the high voltage line of the electric vehicle and the vehicle body, A power supply unit for supplying power to the electric vehicle; And a voltage distribution capacitor (Cd) connected in parallel with the power supply and configured to distribute the voltage of the power supply and a voltage measurement capacitor (Cm) for measuring the voltage of the power supply by voltage distribution. A short circuit detection unit connected to an electric circuit between the vehicle body of the electric vehicle and a power supply line (+,-) to detect a contact resistance between the high voltage line of the electric vehicle and the vehicle body; A control unit (ECU) which analyzes signals input through the short detection unit and determines a short state according to a change in an output voltage between a vehicle body and a power supply unit of the electric vehicle; A converting unit connected to the short circuit detecting unit and the control unit by an electrical circuit to amplify and convert a voltage of the short detecting unit; And a display unit configured to receive and display data determined from the control unit (ECU). 4. The short circuit detection system according to claim 3, wherein a value of the voltage distribution capacitor (Cd) constituting the short circuit detection unit is larger than a value of the voltage measurement capacitor (Cm). 5. The short circuit detection system according to claim 4, wherein the voltage supplied from the voltage measuring capacitor (Cm) to the converter is a voltage of "Cm / (Cm + Cd)" times. The method of claim 5, wherein the conversion unit An analog-to-digital converter (AD converter) for supplying a signal to a control unit (ECU) by digitalizing the voltage supplied to the voltage measuring capacitor (Cm); A unit gain amplifier (Voltage Follower) connected to the electrical circuit between the voltage measuring capacitor (Cm) and the analog-to-digital converter (AD Converter) to insulate the voltage measured by the voltage measuring capacitor (Cm). Short circuit detection system for an electric vehicle, characterized in that it comprises a. 7. The short circuit detection system of an electric vehicle according to claim 6, wherein said voltage measuring capacitor (Cm) comprises a first voltage measuring capacitor (Cm1) and a second voltage measuring capacitor (Cm2). The method of claim 7, wherein the control unit ECU reads the values of the first and second voltage measuring capacitors Cm1 and Cm2 and compares the values, and compares the first and second voltage measuring capacitors ( A short circuit detection system for an electric vehicle, characterized in that the short circuit state is determined to be good if the absolute values of Cm1 and Cm2) are equal to each other and equal to half of a power supply within a set error range. The method of claim 7, wherein the control unit ECU reads the values of the first and second voltage measuring capacitors Cm1 and Cm2 and compares the values, and the value of the first voltage measuring capacitor Cm1 is The short circuit detection system of an electric vehicle, characterized in that it is determined that the short-circuit and insulation breakdown is in progress in the negative (-) line of the power supply if the set value is larger than the set value. The method of claim 7, wherein the control unit ECU reads the values of the first and second voltage measuring capacitors Cm1 and Cm2 and compares the values, and the value of the second voltage measuring capacitor Cm2 is The short circuit detection system of an electric vehicle, characterized in that it is determined that the short-circuit and insulation breakdown is in progress in the positive (+) line of the power supply if the set value is larger than the set value. The CAN interface according to any one of claims 3 to 9, wherein the CAN interface transmits an information signal on whether the power supply unit short-circuit and insulation breakdown proceed from the control unit ECU to another control unit in the vehicle. Wow; And a log in out interface for receiving and transmitting a signal for transmitting a signal for a high voltage line blocking command or a warning command of the electric vehicle and other system inspection and operation from the control unit ECU. Short circuit detection system of an electric vehicle, characterized in that.