KR20150018991A - Apparatus and Method for protecting inverter for eco-friendly vehicle - Google Patents

Abstract

An apparatus for protecting an inverter for an eco-friendly vehicle comprises: a power semiconductor of an inverter for vehicles; a control unit applying input signals to a gate of the power semiconductor; an abnormal signal blocking unit blocking an abnormal signal among the applied input signals; and a noise blocking unit preventing noises from being generated in the gate of the power semiconductor. According to the present invention, it is possible to prevent current charging between the gate and an emitter when dv/dt increases instantaneously, thereby preventing the gate from being turned on abnormally when the power semiconductor is turned off.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to an inverter system of an eco-friendly automobile, and more particularly, to an inverter system of an environmentally friendly automobile, which protects a gate of a power semiconductor during surge input or turn-off switching and prevents an abnormal turn- Protection device and method.

An inverter system of an electric vehicle is a device that converts high-voltage battery DC power into three-phase alternating-current power to generate a motor driving force, and supplies the same to a driving motor to control the torque of the driving motor. For this power conversion, a switching circuit is constructed using a semiconductor device (IGBT, Insulated Gate Bipolar Transistor) capable of high voltage / high current control.

Generally, the internal structure of the inverter IGBT for an environment friendly automobile is composed of six packs of IGBT 110 as shown in FIG. The IGBT 110 is connected to peripheral circuits such as the gate resistor 120 and the bypass resistor 130, and a diagram showing the same is shown in FIG.

The functions of the respective peripheral circuits will be described. The IGBT 110 switches for PWM control and transfer of motor drive energy by a control unit (not shown) of the inverter. Then, the gate resistance 120 affects switching characteristics and loss, limits the surge voltage of the gate voltage, and adjusts the change (dv / dt) of the gate voltage with time.

In addition, the bypass resistor 130 maintains the level of the gate voltage and provides the discharge path of the gate voltage to rapidly discharge the gate voltage upon switching turn-off, thereby improving the switching off characteristic (reduction of the influence of the tail current) .

Generally, the IGBT element has a ratio (Ccg / Cgs) of parasitic capacitors (Ccg) and gate to emitter (Cge) values between the collector and the gate being 1 or more, or a change (dv / dt) When large, the collector current can be turned on when charged to Cge.

Therefore, a device having a small Ccg / Cge ratio of the IGBT should be selected, and a protection circuit configuration is required.

In general, when a negative / positive surge voltage is input or when an IGBT is turned off, a current flowing into an abnormal collector is charged to Cge, and abnormal turn- It was difficult to prevent problems that were turning on.

The driving circuit using the IGBT is driven by voltage control. Therefore, the gate wiring / line for driving the IGBT becomes long, or the excessive switching noise is introduced, which poses a serious problem that the upper IGBT and the lower IGBT can be turned on at the same time to short-circuit the arm and the gate driver.

1. Korean Patent Publication No. 10-2013-0009087 2. Korean Patent Publication No. 10-2010-0051171 3. Korean Patent Publication No. 10-2013-0055892

It is an object of the present invention to provide an apparatus and method for protecting an inverter for an eco-friendly automobile, which is capable of blocking a surge voltage input from a gate of a power semiconductor to an emitter.

It is another object of the present invention to provide an apparatus and method for protecting an inverter for an environment-friendly vehicle that can prevent energy charging between a gate and an emitter of a power semiconductor.

The present invention provides an inverter protection device for an eco-friendly automobile, which can shut off the surge voltage input from the gate of the power semiconductor to the emitter.

The inverter protection device for an environment-

Power semiconductor of inverter;

A control unit for applying an input signal to the gate of the power semiconductor;

An abnormal signal blocking unit for blocking an abnormal signal among the applied input signals; And

And a noise blocking unit for preventing noise from being generated at the gate of the power semiconductor.

At this time, the abnormal signal blocking unit includes a blocking capacitor; And a forward diode connected in series with the blocking capacitor and preventing reverse voltage to the control unit when the power semiconductor is turned off.

The blocking capacitor may be an open mode capacitor that is opened when an abnormal signal is a direct current (DC) signal and is over-current exceeding a predetermined reference value.

The noise blocking unit may include a bypass capacitor for charging the current when the change in the gate voltage of the power semiconductor is equal to or greater than a threshold value; A bypass resistor connected in parallel with the bypass capacitor to discharge a charged current; And a free wheeling diode for discharging the displacement current flowing from the collector of the power semiconductor.

The noise blocking unit may further include a bidirectional Zener diode for blocking a cathode or an anode surge voltage input to the emitter from the gate of the power semiconductor.

In addition, the power semiconductor may be an IGBT (Insulated Gate Transistor).

On the other hand, another embodiment of the present invention includes: an input signal applying step in which a control unit applies an input signal to a gate of a power semiconductor; An abnormal signal confirming step of confirming whether there is an abnormal signal among the input signals to which the abnormal signal blocking unit is applied; And an input signal blocking step of blocking the input signal if the abnormal signal blocking unit has an abnormal signal; The present invention provides an inverter protecting method for an environmentally friendly automobile.

On the other hand, another embodiment of the present invention includes: an input signal applying step in which a control unit applies an input signal to a gate of a power semiconductor; An abnormal signal confirming step of confirming whether there is an abnormal signal among the input signals to which the abnormal signal blocking unit is applied; An input signal blocking step of blocking an input signal if the abnormal signal blocking unit has an abnormal signal; A noise checking step of confirming that a noise is generated in the gate of the power semiconductor; And a current discharging step of discharging current accumulated in the gate of the power semiconductor when the noise shielding part has noise.

According to the present invention, current charging between the gate and the emitter can be prevented when dv / dt instantaneously increases, thereby preventing the gate from abnormally turning on when the power semiconductor is turned off.

 Another effect of the present invention is that the gate can be protected by interrupting the surge voltage input from the gate to the emitter when a negative electrode and / or an anode surge voltage or noise occurs.

Another advantage of the present invention is that the abnormal turn-on of the power semiconductor can be prevented by discharging the energy generated between the gate and the emitter.

1 is a general inverter driving circuit diagram.
2 is a view showing the operation of the IGBT 110 shown in FIG.
3 is a configuration diagram of an inverter protection device 300 for an environmentally friendly automobile according to an embodiment of the present invention.
FIG. 4 is an example in which the inverter protection device 300 shown in FIG. 3 is implemented by a circuit.
FIG. 5 is a flowchart illustrating a blocking process according to an exemplary embodiment of the present invention. Referring to FIG.

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.

Hereinafter, an apparatus and method for protecting an inverter for an environmentally friendly vehicle according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a configuration diagram of an inverter protection device 300 for an environmentally friendly automobile according to an embodiment of the present invention. 3, an inverter protection device 300 for an environmentally friendly automobile includes a power semiconductor 310 of a vehicle inverter, a control unit 340 for applying an input signal to the gate of the power semiconductor 310, An abnormal signal blocking unit 320 for blocking an abnormal signal, a noise blocking unit 330 for preventing noise from being generated at the gate of the power semiconductor 310, and the like.

An IGBT (Insulated Gate Transistor) is mainly used as the power semiconductor 310, but the present invention is not limited thereto, and a bipolar power MOSFET or a metal oxide silicon field effect transistor (MOSFET) device may be used. Power MOSFET devices have a double-diffused metal oxide semiconductor (DMOS) structure, unlike conventional MOSFETs, with high-voltage, high-current operation.

FIG. 4 is an example in which the inverter protection device 300 shown in FIG. 3 is implemented by a circuit. 4 is an example of an inverter for driving a three-phase motor (not shown). 4, the abnormal signal cut-off unit 320 is connected in series with the blocking capacitor 420 and the blocking capacitor 420, and when the power semiconductor 310 is turned off, And a forward diode 421 for preventing reverse voltage to the control unit (340 in FIG. 3).

The blocking capacitor 420 for blocking and / or protecting the DC current passes through the PWM (Pulse Width Modulation) (AC, drive pulse) to turn on / off the power semiconductor 310, (DC component) flowing in the first and second electrodes 310 and 310. Here, the capacitor is a capacitor of a mode in which a capacitor is opened when an overcurrent flows into an open-mode capacitor.

Further, the forward diode 421 of the gate turn-on operation is connected in series with the gate of the power semiconductor 310, the gate resistance 423, and the like. This forward diode 421 operates in a forward direction when the gate of the power semiconductor 310 is turned on to drive the IGBT 310 which is a power semiconductor.

On the contrary, the control unit 340 protects the integrated circuit (IC) or the microcomputer of the control unit 340 by the reverse voltage prevention function.

The gate noise cutoff unit 330 includes a bypass capacitor 434 for charging a current when the change in the gate voltage of the power semiconductor 310 is equal to or more than a threshold value and a bypass capacitor 434 connected in parallel to the bypass capacitor 434, And a freewheeling diode 433 for discharging the displacement current flowing from the collector of the power semiconductor 310. The bypass resistor 431 is connected to the power semiconductor 310 through the bypass resistor 431,

Here, one end of the bypass capacitor 434 is connected to the gate of the power semiconductor 310 and the other end is connected to the emitter of the power semiconductor 310. When the change (dv / dt) of the gate voltage is equal to or more than the threshold value with time, the bypass capacitor 434 flows into the collector C, passes through the capacitor Cce between the collector and the emitter, And charges the current flowing into the capacitor Cge.

Here, the threshold value may be a threshold value that can be determined as an abnormal state of the power semiconductor 310, and may be determined experimentally or may be determined by the characteristics of the power semiconductor.

The bypass resistor 431 is connected in parallel to the bypass capacitor 434 and functions to discharge the current charged in the bypass capacitor 434.

The free wheeling diode 433 is connected in parallel with a gate resistor serially connected to the gate of the power semiconductor 310, the anode is connected to the gate of the power semiconductor 310 and the cathode is connected to the external terminal.

The free wheeling diode 433 is energized when a surge occurs due to the displacement current flowing from the collector of the power semiconductor 310 to discharge energy between the gate and the emitter through the gate resistor 423. Here, the external terminal may be an input terminal to which a control signal for controlling the gate is input, or may be an output terminal.

The noise blocking unit 330 may further include a bidirectional Zener diode 432 for blocking a cathode or an anode surge voltage input to the emitter from the gate of the power semiconductor 310.

 The bidirectional Zener diode 432 has one end connected to the gate of the power semiconductor 310 and the other end connected to the emitter of the IGBT. The bidirectional Zener diode 432 blocks (clamps) the negative / positive surge voltage input to the emitter at the gate of the power semiconductor 310. Thus, the bidirectional Zener diode 432 can protect the GOX layer of the power semiconductor 310.

FIG. 5 is a flowchart illustrating a blocking process according to an exemplary embodiment of the present invention. Referring to FIG. Referring to FIG. 5, the control unit 340 of FIG. 3 applies an input signal to the gate of the power semiconductor 310 (step S500).

The abnormal signal blocking unit 320 of FIG. 3 checks whether there is an abnormal signal among the applied input signals, and if there is an abnormal signal, blocks the input signal (steps S510 and S530). Otherwise, if there is no abnormal signal, it operates normally (step S520).

Similarly, a process of blocking the noise of the power semiconductor is also performed. The process of isolating the noise includes a process of confirming that noise is generated at the gate of the power semiconductor 310 in addition to the flowchart of FIG. 5, The current flowing through the gate of the transistor Q3 is discharged.

300: Protection device for automobile inverter
310: Power Semiconductor
320: abnormal signal block
330: Noise-
340:
421: forward diode
423: Gate resistance
431: Bypass resistance
432: bi-directional zener diode
433: Free-wheeling diode
434: Bypass capacitor

Claims (13)

Power semiconductor of inverter;
A control unit for applying an input signal to the gate of the power semiconductor;
An abnormal signal blocking unit for blocking an abnormal signal among the applied input signals; And
A noise blocking unit for preventing noise from being generated at the gate of the power semiconductor;
And an inverter for protecting the inverter of the environmentally friendly automobile.
The method according to claim 1,
The abnormality signal blocking unit includes: a blocking capacitor; And a forward diode connected in series with the blocking capacitor to prevent reverse voltage to the control unit when the power semiconductor is turned off.
3. The method of claim 2,
Wherein the blocking capacitor is an open mode capacitor that is opened when an abnormal signal is a DC (Direct Current) signal and is overcurrent of a predetermined reference value or more. The method according to claim 1,
Wherein the noise blocking unit includes: a bypass capacitor for charging a current when a change in the gate voltage of the power semiconductor is equal to or greater than a threshold value; A bypass resistor connected in parallel with the bypass capacitor to discharge a charged current; And a freewheeling diode for discharging the displacement current flowing from the collector of the power semiconductor.
5. The method of claim 4,
Wherein the noise blocking unit further includes a bidirectional Zener diode for blocking a cathode or an anode surge voltage input to the emitter from the gate of the power semiconductor.
The method according to claim 1,
Wherein the power semiconductor is an IGBT (Insulated Gate Transistor).
An input signal applying step in which the control unit applies an input signal to the gate of the power semiconductor;
An abnormal signal confirming step of confirming whether there is an abnormal signal among the input signals to which the abnormal signal blocking unit is applied; And
An input signal blocking step of blocking an input signal if the abnormal signal blocking unit has an abnormal signal;
And a protection circuit for protecting the inverter.
An input signal applying step in which the control unit applies an input signal to the gate of the power semiconductor;
An abnormal signal confirming step of confirming whether there is an abnormal signal among the input signals to which the abnormal signal blocking unit is applied;
An input signal blocking step of blocking an input signal if the abnormal signal blocking unit has an abnormal signal;
A noise checking step of confirming that a noise is generated in the gate of the power semiconductor; And
A current discharging step of discharging a current held in the gate of the power semiconductor when the noise shielding part has noise;
And a protection circuit for protecting the inverter. 9. The method according to claim 7 or 8,
The abnormality signal blocking unit includes: a blocking capacitor; And a forward diode connected in series with the blocking capacitor and preventing a reverse voltage to the control unit when the power semiconductor is turned off.
10. The method of claim 9,
Wherein the blocking capacitor is an open mode capacitor that is opened when an abnormal signal is a direct current (DC) signal and is overcurrent of a predetermined reference value or more.
9. The method of claim 8,
Wherein the noise blocking unit includes: a bypass capacitor for charging a current when a change in the gate voltage of the power semiconductor is equal to or greater than a threshold value; A bypass resistor connected in parallel with the bypass capacitor to discharge a charged current; And a free wheeling diode for discharging the displacement current flowing from the collector of the power semiconductor.
12. The method of claim 11,
Wherein the noise blocking unit further comprises a bidirectional Zener diode for blocking a cathode or an anode surge voltage input to the emitter from the gate of the power semiconductor.
9. The method according to claim 7 or 8,
Wherein the power semiconductor is an IGBT (Insulated Gate Transistor).

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