KR20150019224A - Apparatus and Method for detecting short circuit of inverter system - Google Patents

Abstract

An apparatus for detecting a short circuit in an inverter system comprises: a power module in which multiple power semiconductors are arranged on substrates; a short circuit detecting unit which senses a voltage using conductor resistance which is resistance of a conductor having a specific measurement distance and detects whether a short circuit occurs; and a control unit which blocks an output of the multiple power semiconductors if the short circuit is detected. According to the present invention, it is possible to efficiently improve a method for detecting a short circuit between high-voltage output cables in an inverter system for electrical vehicles by quickly cutting off occurrence of overvoltage.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short-

The present invention relates to an inverter system, and more particularly, to an inverter system for an electric vehicle, which efficiently improves the detection method of a high-voltage output cable short-circuit, thereby timely detecting short- The present invention relates to an apparatus and a method for short-circuit detection of an inverter system for preventing the burn-in of an inverter when an over-current is generated by short-circuiting between high-voltage cables, thereby enhancing safety and durability of an electric vehicle.

A permanent magnet type motor is applied to the electric vehicle as a driving means. This permanent magnet type motor is driven by a voltage and / or a current that is transmitted through a power cable from an inverter that converts a DC voltage to a three-phase voltage by a PWM (Pulse Width Modulation) signal of the controller.

Therefore, when a problem occurs in the power cable for supplying the three-phase voltage output from the inverter to the motor, the motor is not driven smoothly, and the inverter is damaged due to the high voltage and high current being induced in the inverter.

In addition, when a short circuit occurs between the power cables that transmit power to the motor, a large pulsating torque is generated to cause operation inconsistency, which causes the occurrence of an accident and damages mechanical parts mechanically connected to the motor.

Particularly, when a short circuit occurs between the power cables, if a large current is conducted to the power devices constituting the inverter and rapid current interruption can not be performed, the power devices are thermally broken.

A common cable short-circuit sensing method is to measure the current (U, V, W) of each phase by applying a sequential switching sequence to the inverter before driving the motor and to measure the current It is determined that a short circuit has occurred in the corresponding power cable.

1 to 4 show an example of such a cable short-circuit sensing method. 1 is a view showing a control and input structure for detecting disconnection of an inverter output cable of an electric vehicle. 1, a U-phase V-phase W phase output cable connector 130, 140, 150 formed at an output terminal of an inverter, and a U-phase V-phase W-phase output cable connector 130, 140, 150 for receiving a drive signal from a CPU and generating an output current, Current sensors 160, 170 and 180 for sensing output currents of V and W, a motor 190, and the like.

2 is a flowchart of the detection of an inverter high voltage output cable short circuit of an electric vehicle. The inverter 120 compares the sensed current value from the current sensors 160, 170 and 180 to determine whether the input voltage is higher than the reference voltage, and detects that the overcurrent flows (1 & cir &

(③ to ⑤). It is judged whether the overcurrent or overcurrent caused by the short-circuit of the inverter output cable is normal and the overcurrent due to the control error is detected.

FIG. 3 is a view showing the current waveforms of the U, V, and W phases sensed from the current sensor according to FIG. 2, and FIG. 4 is a diagram showing a voltage waveform according to FIG. That is, even when an overcurrent (for example, 300A, 400A, or 500A) occurs, only the sensing output voltage is 4.5V.

However, it is difficult to accurately calculate DELTA T due to the influence of the low-pass filter for eliminating the switching noise from the output delay time of the current sensor and the noise. Therefore, there is a disadvantage that it is difficult to precisely sense a high-voltage cable short circuit.

In addition, a huge overcurrent flows instantaneously during a short-circuit between high-voltage output cables, and a current sensor capable of sensing currents from a few hundred amperes to a few thousand amperes for smaller, faster and more precise sensing. However, there is a disadvantage that a higher performance current sensor having a larger current sensing range is more expensive.

1. Korean Patent No. 10-1091636 2. Korean Patent Publication No. 10-2012-0061660 3. Korean Patent Laid-Open No. 10-2009-0109373

The present invention has been proposed in order to solve the problem according to the above background art, and it is an object of the present invention to provide a motor control apparatus and a control method thereof, which timely detects a short circuit of an inverter output cable due to a decrease in insulation performance inside a motor, And it is an object of the present invention to provide a short-circuit detection apparatus and method of an inverter system that can efficiently improve the detection method.

It is another object of the present invention to provide an apparatus and method for short-circuit detection of an inverter system that improves safety and durability of an electric vehicle by preventing burn-out of an inverter when an overcurrent due to a short circuit between high-voltage cables is generated.

In order to achieve the above-mentioned object, the present invention efficiently detects a short-circuit of the output cable of the inverter due to a decrease in insulation performance inside the motor in a timely manner and quickly cuts off the output, thereby efficiently detecting the high- A short-circuit detection device for an inverter system is provided.

The short circuit detecting device of the inverter system comprises:

A power module in which a plurality of power semiconductors are disposed on a substrate;

A short detection unit for detecting a short circuit by sensing a voltage using a line resistance which is a resistance of a line having a predetermined measurement distance on a substrate formed between the plurality of power semiconductors; And

And a control unit for shutting down the output of the plurality of power semiconductors when a short circuit is detected.

Here, the short detection unit may include: a voltage sensing unit that senses a voltage using a wire resistance; And a voltage comparator comparing the sensed voltage with a reference voltage.

In addition, the plurality of power semiconductors are connected in parallel, and the predetermined measuring distance may be a length formed between the parallel lines.

The wire resistance may be any one of a wire resistance of a U, V, W output high voltage connector connected to a three-phase motor.

In addition, it may further include a plurality of current sensors for sensing currents of the U, V, W output high voltage connector. At this time, the plurality of current sensors are not high performance.

In addition, the plurality of power semiconductors may be an IGBT (Insulated Gate Bipolar Mode Transistor).

In addition, the lead may be DBC (Direct Bond Copper).

On the other hand, an embodiment of the present invention includes a voltage sensing step of sensing a voltage using a line resistance, which is a resistance of a line having a certain measurement distance on a substrate formed between a plurality of power semiconductors; Detecting whether a short circuit is detected using the sensed voltage; And an output blocking step of blocking the outputs of the plurality of power semiconductors when a short circuit is detected as a result of detection of the short circuit.

In this case, the detecting step may include detecting a voltage using a lead wire resistance; And comparing the sensed voltage with a reference voltage.

The method may further include the step of sensing the current of the U, V, W output high voltage connector using a plurality of current sensors.

According to the present invention, by adding the internal wire resistance and the voltage sensing method using the voltage comparator in the current sensing method, it is possible to accurately and quickly prevent the occurrence of the overcurrent, It is possible to efficiently improve the short-circuit detection method of the high-voltage output cable of the inverter system of the vehicle.

Another advantage of the present invention is that the safety and / or durability of the hybrid vehicle can be enhanced by preventing burn-out of the inverter when an overcurrent due to a short circuit between high-voltage cables is generated.

Another advantage of the present invention is that since a voltage sensing method using an internal lead resistance is used, a separate high-performance current sensor is not needed, which is advantageous in reducing cost, simplifying the process, and reducing cost .

1 is a view showing a control and input structure for detecting an inverter output cable disconnection of a general electric vehicle.
Fig. 2 is a flow chart of the inverter high voltage output cable short circuit detection of the electric vehicle according to Fig. 1;
FIG. 3 is a diagram showing current waveforms of U, V, and W sensed from the current sensor according to FIG.
FIG. 4 is a view showing a voltage waveform according to FIG. 2. FIG.
5 is a conceptual diagram for detecting disconnection of an inverter output cable of an electric vehicle according to an embodiment of the present invention.
6 is a configuration diagram of a short circuit detecting apparatus 600 of an inverter system according to an embodiment of the present invention.
7 is a flowchart illustrating a short circuit detection process of an inverter system according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for similar elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term "and / or" includes any combination of a plurality of related listed items or any of a plurality of related listed items.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be construed as ideal or overly formal in meaning unless explicitly defined in the present application Should not.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an apparatus and method for detecting a short circuit of an inverter system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

5 is a conceptual diagram for detecting disconnection of an inverter output cable of an electric vehicle according to an embodiment of the present invention. Referring to FIG. 5, a first power semiconductor 510-1 and a second power semiconductor 510-2 are arranged in parallel on a substrate 560 of a power module.

A space is formed between the first power semiconductor 510-1 and the second power semiconductor 510-2, and a predetermined measurement distance 540 for detecting a short circuit is formed on the space.

The predetermined measurement distance 540 is a distance between the first measurement point 520 and the second measurement point 530.

Therefore, an overcurrent generated when the inverter output cable is short-circuited through the overcurrent path 550 by using the internal wire resistance component of the substrate by the constant measurement distance 540 is applied to the first measurement point 520 and the second measurement point 530 The voltage generated by the resistance component of the constant measuring distance 540 is sensed.

Using this sensed voltage, the inverter high voltage output cable short circuit is detected and the inverter high voltage output cable short circuit is detected accurately. In addition, when such a short circuit occurs, the high voltage output is cut off.

IGBTs (Insulated Gate Bipolar Mode Transistors) are used as the power semiconductors 510-1 and 510-2, but the present invention is not limited thereto, and bipolar, power MOSFET (Metal Oxide Silicon Field Effect Transistor) devices and the like can be used. Power MOSFET devices have a double-diffused metal oxide semiconductor (DMOS) structure, unlike conventional MOSFETs, with high-voltage, high-current operation.

In addition, the lead wire is thinned by DBC (Direct Bond Copper).

6 is a configuration diagram of a short circuit detecting apparatus 600 of an inverter system according to an embodiment of the present invention. 6, a short circuit detecting device 600 of an inverter system includes a power module 620 in which a plurality of power semiconductors 621 are disposed on a substrate (560 of FIG. 5), a plurality of power semiconductors 621 A short detection unit 610 for detecting a short circuit by sensing a voltage using a line resistance which is a resistance of a line having a predetermined measurement distance (540 in FIG. 5) on the substrate formed on the substrate, And a control unit 601 for shutting off the output of the control unit 621.

The short detection unit 610 includes a voltage sensing unit 613 that senses a voltage on a predetermined measurement distance 540 using a lead resistance and a voltage comparison unit 611 that compares the sensed voltage with a reference voltage 612 . Of course, the voltage sensing unit 613 and / or the voltage comparator 611 are shown as one in FIG. 6, but three voltage sensing units for the U-phase voltage, the V-phase voltage, and the W- (613) can be constructed. In addition, three voltage comparators 611 may be configured for the three voltage sensing units 613.

Output cable connectors 630, 640, and 650 are provided at one end of the power module 620 to supply current to the motor 690.

The motor 690 uses a three-phase motor, in which a U output cable connector 630, a V output cable connector 640 and a W output cable connector 650 are configured. The motor 690 is a motor for an electric vehicle. The electric vehicle is an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid vehicle (PHV), and a fuel vehicle.

6, since the current sensing method in which the current sensing method is used between the motor 690 and the output cable connectors 630, 640, 650 is widely known, It will be omitted.

These current sensors 660, 670, and 680 use a general current sensor instead of a high-performance current sensor. Therefore, it is possible to selectively perform short-circuit detection while solving the problem of using the current sensor according to the background art.

The control unit 601 includes a microprocessor and / or a microcomputer as a CPU (Central Processing Unit), receives short circuit information of the high voltage cable from the short detection unit 610, Off. Therefore, no current is supplied from the power semiconductor 621. [ In this case, it is possible to prevent the inverter from being burned out due to the overcurrent.

7 is a flowchart illustrating a short circuit detection process of an inverter system according to an embodiment of the present invention. Referring to FIG. 7, the left-hand side flowchart is a process (S710, S713, S715) of detecting a short circuit by sensing a current through a general current sensor, and the right- (Steps S720, S723, and S725).

First, referring to the left-hand side flowchart, a current is sensed through a current sensor (660, 670, 680 in FIG. 6), and a sensing current and a reference current are compared by a determination logic (steps S710 and S713). By detecting the overcurrent by the determination logic and controlling the overcurrent, the gate output of the power semiconductor 621 is shut off (step S715).

Simultaneously, explaining the right flow diagram, the voltage is sensed by using a line resistance which is a resistance of a conductor having a predetermined measurement distance on a substrate formed between a plurality of power semiconductors (step S720). The sensed voltage is compared with a reference voltage to judge whether or not it is short-circuited (step S713).

As a result of the determination, if the short circuit is detected, the output of the power semiconductor 621 is shut off (steps S725 and S730).

110, 610:
120, 620: power module
130, 630: U Output cable connector
140, 640: V output cable connector
150, 650: W output cable connector
160, 170, 180, 660, 670, 680: Current sensor
190, 690: motor
510-1,510-2: Power Semiconductor
520: first measurement point 530: second measurement point
540: constant measuring distance
550: Overcurrent path
560: substrate 610: short circuit detection unit
611: Voltage comparison unit 613: Voltage sensing unit
612: Reference voltage

Claims (14)

A power module in which a plurality of power semiconductors are disposed on a substrate;
A short detection unit for detecting a short circuit by sensing a voltage using a line resistance which is a resistance of a line having a predetermined measurement distance on a substrate formed between the plurality of power semiconductors; And
A controller for shutting off the outputs of the plurality of power semiconductors when a short circuit is detected;
And a short-circuit detection unit for detecting short-circuit of the inverter system.
The method according to claim 1,
The short detection unit includes: a voltage sensing unit for sensing a voltage using a lead resistance; And a voltage comparator for comparing the sensed voltage with a reference voltage.
The method according to claim 1,
Wherein the plurality of power semiconductors are connected in parallel and the predetermined measuring distance is a length formed between the parallel lines.
The method according to claim 1,
And wherein the lead resistance is any one of a lead resistance of the U, V, W output high voltage connector connected to the three-phase motor.
5. The method of claim 4,
Further comprising a plurality of current sensors for sensing a current of the U, V, W output high voltage connector, wherein the plurality of current sensors are not high performance.
The method according to claim 1,
Wherein the plurality of power semiconductors are IGBTs (Insulated Gate Bipolar Mode Transistors).
The method according to claim 1,
Wherein the lead wire is a DBC (Direct Bond Copper). A voltage sensing step of sensing a voltage using a lead wire resistance which is a resistance of a lead having a predetermined distance on the substrate formed between the plurality of power semiconductors;
Detecting whether a short circuit is detected using the sensed voltage; And
An output blocking step of blocking output of the plurality of power semiconductors when a short circuit is detected as a result of detection;
And a short-circuit detection method of the inverter system.
9. The method of claim 8,
The short-circuit detecting step may include: sensing a voltage using a lead wire resistance; And comparing the sensed voltage with a reference voltage. ≪ RTI ID = 0.0 > 8. < / RTI >
9. The method of claim 8,
Wherein the plurality of power semiconductors are connected in parallel and the predetermined measuring distance is a length formed between the parallel lines.
9. The method of claim 8,
Wherein the lead resistance is any one of a lead resistance of U, V, W output high voltage connector connected to the three-phase motor.
12. The method of claim 11,
Sensing a current of the U, V, W output high-voltage connector using a plurality of current sensors, wherein the plurality of current sensors are not high-performance.
9. The method of claim 8,
Wherein the plurality of power semiconductors are IGBTs (Insulated Gate Bipolar Mode Transistors).
9. The method of claim 8,
Wherein the lead wire is a DBC (Direct Bond Copper).

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