WO2018093217A1

WO2018093217A1 - Electric vehicle power relay assembly and method for driving same

Info

Publication number: WO2018093217A1
Application number: PCT/KR2017/013186
Authority: WO
Inventors: 권대환; 임성현
Original assignee: 주식회사 유라코퍼레이션
Priority date: 2016-11-18
Filing date: 2017-11-20
Publication date: 2018-05-24
Also published as: KR20180056175A

Abstract

The present invention relates to an electric vehicle power relay assembly and a method for driving the same and, specifically, to an electric vehicle power relay assembly, which performs a pre-charge process by means of a semiconductor switch, instead of a gas filled type relay used as a pre-charge relay, and a method for driving the same. Further, the present invention comprises: a main relay; a pre-charge relay comprising a semiconductor switching element; a gate voltage supply unit for supplying a gate voltage to turn on the pre-charge relay before the main relay is turned on, and to turn on the pre-charge relay before the main relay is turned off; and a control unit for controlling the gate voltage supply unit. Therefore, the present invention allows performance of a pre-charge process by means of a semiconductor switch instead of an existing gas filled type relay.

Description

Power relay assembly for electric vehicle and its driving method

The present invention relates to a power relay assembly for an electric vehicle and a driving method thereof, and more particularly, to a power relay assembly for an electric vehicle and a driving method thereof for performing a precharge process by replacing a gas-charged relay used as a precharge relay with a semiconductor switch. It is about.

In general, a power relay assembly (PRA) is located between a high voltage battery and a motor used in an electric vehicle to selectively supply power of a high voltage battery, and is a main relay and a precharge. It includes a relay (Pre-Charge Relay), a precharge resistor and a busbar.

The conventional power relay assembly performs a precharge process through the precharge relay, thereby preventing a high inrush current from occurring when the main relay is connected. This inrush current is generated in proportion to the voltage of the high voltage battery and the capacitor capacity of the motor controller input stage, and may act as a major factor in reducing the endurance life of the motor controller and the capacitor.

Therefore, the conventional power relay assembly charges the capacitor of the motor controller input terminal through the precharge relay and the precharge resistor before connecting the main relay to limit the generation of inrush current due to the voltage difference.

In the conventional power relay assembly, the precharge relay is mainly a gas-charged relay filled with a special gas for spark suppression, and the precharge resistor is a cement resistor having a high watt.

On the other hand, the gas-charged relay used in the conventional power relay assembly has a high cost because of the high cost, the precharge resistance has a large size and heavy problems.

That is, due to the conventional gas-charged relay and the precharge resistor, the manufacturing cost of the power relay assembly itself increases, and the overall size and weight also increase.

In addition, the conventional gas-charged relay is composed of a structure including a fixed contact, a variable contact and a magnet, mechanical stability is essential for the control of the spark and also affects the sensing operation of the adjacent sensor by the magnet there was.

The present invention has been made in view of the above problems, and by replacing the conventional gas-charged relay with a semiconductor switch, the power relay assembly for electric vehicles and the driving thereof that can reduce the cost burden and reduce the size and weight of the power relay assembly The purpose is to provide a method.

The objects of the present invention are not limited to the above-mentioned objects, and other objects which are not mentioned will be clearly understood by those skilled in the art from the following description.

The present invention for achieving the above object is a main relay connected between the high voltage battery and the load; A precharge relay comprising a semiconductor switching element connected to both ends of the main relay; A gate voltage supply unit supplying a gate voltage to the precharge relay to turn on the precharge relay before the main relay is turned on and turn on the precharge relay before the main relay is turned off; And a control unit controlling the gate voltage supply unit.

In a preferred embodiment, the gate voltage supply unit supplies the gate voltage of any one of a first gate voltage and a second gate voltage lower than the first gate voltage and equal to or greater than a threshold voltage to the precharge relay.

In a preferred embodiment, the gate voltage supply unit, when the precharge relay is turned on before the main relay is turned on, supplies a second gate voltage to limit the drain current of the precharge relay.

In a preferred embodiment, the gate voltage supply unit includes a DC / DC converter for outputting a gate voltage.

In a preferred embodiment, the DC / DC converter includes a switching transistor for switching the input voltage to output at least two gate voltages.

In a preferred embodiment, the DC / DC converter comprises at least two transformers having different turns ratios.

In a preferred embodiment, the DC / DC converter comprises a switch and a resistor for regulating the input voltage.

In addition, the present invention is a method of driving a power relay assembly for an electric vehicle performed in a power relay assembly for an electric vehicle, (1) the power relay assembly for the electric vehicle, the gate voltage is supplied to the precharge relay which is a semiconductor switching element through a gate voltage supply; Supplying, turning on the precharge relay before the main relay is turned on; (2) the power relay assembly for the electric vehicle turning off the precharge relay when the main relay is turned on; (3) the power relay assembly for the electric vehicle supplying a gate voltage back to the precharge relay through the gate voltage supply to turn on the precharge relay before the main relay is turned off; And (4) turning off the precharge relay, when the main relay is turned off, by the power relay assembly for the electric vehicle.

In a preferred embodiment, in the first step, the gate voltage supply part supplies a second gate voltage lower than a first gate voltage and equal to or greater than a threshold voltage to the precharge relay to limit the drain current of the precharge relay. .

In a preferred embodiment, in the third step, the gate voltage supply unit supplies a first gate voltage to the precharge relay.

In a preferred embodiment, the DC / DC converter outputs at least two gate voltages by adjusting the switching duty and switching frequency of the switching transistor for switching the input voltage.

In a preferred embodiment, the DC / DC converter outputs at least two gate voltages using at least two transformers having different turns ratios.

In a preferred embodiment, the DC / DC converter outputs at least two gate voltages by using a resistor and a switch for adjusting an input voltage.

According to the above-described problem solving means, the present invention provides a precharge relay composed of a main relay, a semiconductor switching element, and a precharge relay before the main relay is turned on by supplying a gate voltage and before the main relay is turned off. Since the gate voltage supply unit for turning on the relay and the control unit for controlling the gate voltage supply unit are provided, there is an effect of performing the precharge process by replacing the existing gas-charged relay with a semiconductor switch.

In addition, the present invention can omit the gas-charged relay and the precharge resistor, thereby reducing the cost of the power relay assembly, it is possible to reduce the size and weight.

1 is a view for explaining a power relay assembly for an electric vehicle according to an embodiment of the present invention.

2 is a view for explaining the detailed configuration of the power relay assembly for an electric vehicle.

3 is a view for explaining the operation of the power relay assembly for an electric vehicle.

4A and 4B are diagrams for explaining a DC / DC converter of a gate voltage supply unit according to a first embodiment of the present invention.

5 is a view for explaining a DC / DC converter of the gate voltage supply unit according to a second embodiment of the present invention.

6 is a view for explaining a DC / DC converter of the gate voltage supply unit according to a third embodiment of the present invention.

7 is a view for explaining a method of driving a power relay assembly for an electric vehicle according to an embodiment of the present invention.

In the following description specific details of the invention have been presented to provide a thorough understanding of the invention, and it is well known in the art that the invention may be readily practiced without these specific details and by modification thereof. It will be self-evident to those who have

Hereinafter, a preferred embodiment according to the present invention will be described in detail with reference to the accompanying Figures 1 to 7, but with a focus on the parts necessary to understand the operation and action according to the present invention.

1 is a view for explaining a power relay assembly for an electric vehicle according to an embodiment of the present invention, Figure 2 is a view for explaining the detailed configuration of the power relay assembly for an electric vehicle, Figure 3 is a power relay assembly of the electric vehicle It is a figure for explaining an operation process.

1 to 3, an electric vehicle power relay assembly according to an embodiment of the present invention includes a main relay 100, a precharge relay 200, a gate voltage supply unit 300, and a controller 400. It is composed.

The main relay 100 is connected between the high voltage battery 10 and the load 20, and the first main relay 110 and the high voltage battery 10 connected to the positive electrode (+) of the high voltage battery 10. The second main relay 120 is connected to the cathode (-) of the.

In addition, the main relay 100 performs a function of connecting or disconnecting the power of the high voltage battery 10 to be supplied to the load 20, and to operate according to a control signal input from the controller 400 to be described later. It may be provided.

The precharge relay 200 is connected to the input terminal and the output terminal of the main relay 100, and by lowering the voltage difference across the main relay 100 when the main relay 100 is turned on or off, Precharge function prevents inrush current and prevents spark.

Preferably, the precharge relay 200 is not a mechanical switch having a contact, but a semiconductor switching element including a field effect transistor (FET), and the gate voltage from the gate voltage supply unit 300 to be described later. It may be provided to turn on.

In particular, the precharge relay 200 is connected to both ends of the first main relay 110 connected to the positive electrode of the high voltage battery 10 among the first main relay 110 and the second main relay 120. Can be connected.

Thus, as shown in FIG. 3, the precharge relay 200 is first turned on before the first main relay 110 is turned on and is turned off after the first main relay 110 is turned on. Even when the first main relay 110 is turned off, the precharge relay 200 is first turned on so that the first main relay 110 is turned off and then turned off. In addition, since the inrush current is less likely to occur, the second main relay 120 is turned on first and turned off last.

The gate voltage supply unit 300 is for supplying a gate voltage to the precharge relay 200. Instead of supplying the same gate voltage every time, the gate voltage supply unit 300 may supply at least two gate voltages to the precharge relay 200. It is provided to be.

Preferably, the gate voltage supply unit 300 may be provided to supply the gate voltage of any one of a first gate voltage and a second gate voltage lower than the first gate voltage and greater than or equal to the threshold voltage to the precharge relay 200. have. For example, the first gate voltage may be 15V, and the second gate voltage may be 3V to 5V.

That is, the gate voltage supply unit 300 switches the semiconductor by supplying a second gate voltage to the precharge relay 200 when the precharge relay 200 needs to be turned on before the main relay 100 is turned on. By limiting the drain current of the precharge relay 200 made of a device to lower the current output to the first main relay 110 and to prevent the inrush current is generated in the first main relay 110.

When the precharge relay 200 needs to be turned on before the main relay 100 is turned off, the gate voltage supplier 300 supplies the first gate voltage to the precharge relay 200. do.

To this end, the gate voltage supply unit 300 receives a driving driver 310 for controlling the gate voltage and a gate voltage stepped up or down by receiving power from a low voltage battery mounted in an electric vehicle, to the driving driver 310. It may be configured to include a DC / DC converter 320 to output.

The control unit 400 performs overall control of an electric vehicle power relay assembly. In particular, the control unit 400 controls the gate voltage supply unit 300 so that the precharge relay is turned on and off when the main relay 100 is turned on. Allow an appropriate gate voltage to be supplied to 200.

In addition, the control unit 400 senses the power applied from the high voltage battery 10 through the current sensor 500 connected between the high voltage battery 10 and the first main relay 110, the precharge relay 200 and the main relay 100 may be controlled.

In addition, the control unit 400 may operate by receiving control information from a battery management system (BMS) mounted in an electric vehicle, and may transmit information on a control state of each relay and whether a failure occurs. have.

Therefore, the power relay assembly for an electric vehicle according to an embodiment of the present invention can replace the existing gas-charged relay with a semiconductor switch and omit the precharge resistor, thereby reducing the cost burden and size and weight of the power relay assembly. .

On the other hand, the gate voltage supply unit 300, in particular, the DC / DC converter 320 of the power relay assembly for an electric vehicle according to an embodiment of the present invention can be applied in various forms.

Hereinafter, the DC / DC converter 320 constituting the gate voltage supply unit 300 of the present invention will be described.

4A and 4B are diagrams for describing a DC / DC converter of a gate voltage supply unit according to a first embodiment of the present invention, and FIG. 5 is a gate voltage supply unit according to a second embodiment of the present invention. FIG. 6 is a diagram for describing a DC / DC converter, and FIG. 6 is a diagram for describing a DC / DC converter of a gate voltage supply unit according to a third embodiment of the present invention.

First, referring to FIGS. 4A and 4B, the DC / DC converter 320 may include a switching transistor 321 for switching an input voltage to output at least two gate voltages. . In this case, two types of gate voltages may be output by adjusting the switching frequency and the switching duty of the switching transistor 321, and the gate voltages are output to the driving driver 310.

In addition, as shown in FIG. 5, the DC / DC converter 320 may include at least two transformers 322 having different turns ratios. In this case, the two transformers 322 are preferably provided to be movable. The output terminals of the two transformers 322 may be connected to the driving driver 310.

As illustrated in FIG. 6, the DC / DC converter 320 may include at least two

resistors

323 and 325 and at least two

switches

324 and 326 to adjust an input voltage. . In addition, a driving driver 310 may be connected to an output terminal of the DC / DC converter 320.

In this case, when the first gate voltage is to be output from the DC / DC converter 320, the first switch 324 is turned on, and when the second gate voltage is to be output, the first resistor 323 and the first gate voltage are output. The second switch 326 may be turned on to output a low voltage by the second resistor 325.

On the other hand, in addition to the above-described embodiment, a DC / DC converter may be configured by applying various modifications capable of outputting at least two kinds of gate voltages.

Referring to FIG. 7, a driving method of an electric vehicle power relay assembly performed in an electric vehicle power relay assembly according to an embodiment of the present invention will be described.

However, all of the functions performed in the method of driving the power relay assembly for an electric vehicle illustrated in FIG. 7 are performed in the power relay assembly for the electric vehicle described with reference to FIGS. 1 to 6, and thus, even without explicit description, FIGS. 1 to 6. All functions described with reference to are performed in the method for driving the power relay assembly for an electric vehicle according to a preferred embodiment of the present invention, all functions described with reference to FIG. 7 are power relay assembly for an electric vehicle according to a preferred embodiment of the present invention. Note that this is done intact.

First, when the main relay is to be turned on, the gate voltage is supplied to the precharge relay, which is a semiconductor switching element, through the gate voltage supply unit, and the precharge relay is turned on before the main relay is turned on (S100).

In this case, the gate voltage supply unit may limit the drain current of the precharge relay by supplying a second gate voltage that is lower than a first gate voltage and equal to or greater than a threshold voltage to the precharge relay. As a result, the inrush current does not occur when the first main relay is turned on.

The gate voltage supply unit may include a DC / DC converter for outputting a gate voltage. For example, the DC / DC converter may adjust at least two types of switching duty and switching frequency of a switching transistor for switching an input voltage. Output at least two gate voltages using at least two transformers having different turns ratios, or output at least two gate voltages using resistors and switches for adjusting the input voltage; Can be.

Next, when the main relay is turned on, the precharge relay is turned off (S200).

Next, when the main relay is to be turned on, the precharge relay is turned on again before the main relay is turned off by supplying a gate voltage back to the precharge relay through the gate voltage supply unit (S300).

In this case, the gate voltage supply unit supplies a first gate voltage to the precharge relay.

Next, after the main relay is turned off, the precharge relay may be turned off (S400).

Although the preferred embodiments of the present invention have been described above by way of example, the scope of the present invention is not limited to these specific embodiments, and may be appropriately changed within the scope described in the claims.

Claims

A main relay connected between the high voltage battery and the load;

A precharge relay comprising a semiconductor switching element connected to both ends of the main relay;

A gate voltage supply unit supplying a gate voltage to the precharge relay to turn on the precharge relay before the main relay is turned on and turn on the precharge relay before the main relay is turned off; And

And a control unit for controlling the gate voltage supply unit.
The method of claim 1,

The gate voltage supply unit is a power relay assembly for an electric vehicle, characterized in that for supplying the gate voltage of any one of the first gate voltage and the second gate voltage lower than the first gate voltage and more than the threshold voltage to the precharge relay.
The method of claim 2,

The gate voltage supply unit, when the precharge relay is turned on before the main relay is turned on, supplies a second gate voltage to limit the drain current of the precharge relay.
The method according to any one of claims 1 to 3,

And the gate voltage supply unit comprises a DC / DC converter for outputting a gate voltage.
The method of claim 4, wherein

The DC / DC converter includes a switching transistor for switching an input voltage to output at least two gate voltages.
The method of claim 4, wherein

The DC / DC converter includes at least two transformers having different turns ratios.
The method of claim 4, wherein

The DC / DC converter comprises a resistor and a switch for regulating an input voltage.
A driving method of an electric vehicle power relay assembly performed in an electric vehicle power relay assembly,

(1) the power relay assembly for the electric vehicle supplying a gate voltage to a precharge relay, which is a semiconductor switching element, through a gate voltage supply unit to turn on the precharge relay before the main relay is turned on;

(2) the power relay assembly for the electric vehicle turning off the precharge relay when the main relay is turned on;

(3) the power relay assembly for the electric vehicle supplying a gate voltage back to the precharge relay through the gate voltage supply to turn on the precharge relay before the main relay is turned off; And

And (4) turning off the precharge relay when the main relay is turned off, by the power relay assembly for the electric vehicle.
The method of claim 8,

In the first step, the gate voltage supply unit supplies a second gate voltage lower than a first gate voltage and equal to or greater than a threshold voltage to the precharge relay to limit the drain current of the precharge relay. How to drive a power relay assembly.
The method of claim 9,

And in the third step, the gate voltage supply unit supplies a first gate voltage to the precharge relay.
The method according to any one of claims 8 to 10,

The gate voltage supply unit, the method of driving a power relay assembly for an electric vehicle, characterized in that it comprises a DC / DC converter for outputting a gate voltage.
The method of claim 11,

The DC / DC converter controls the switching duty and switching frequency of the switching transistor for switching the input voltage, and outputs at least two gate voltages.
The method of claim 11,

The DC / DC converter outputs at least two gate voltages using at least two transformers having different turns ratios.
The method of claim 11,

The DC / DC converter outputs at least two gate voltages by using a resistor and a switch for adjusting an input voltage.