阅读说明：本技术 一种igbt软关断保护电路、igbt驱动电路及用电设备 (IGBT soft turn-off protection circuit, IGBT drive circuit and electric equipment ) 是由 谭章德 郑培杰 刘旭龙 张敏 李通 于 2021-08-13 设计创作，主要内容包括：本发明涉及一种IGBT软关断保护电路、IGBT驱动电路及用电设备,该IGBT软关断保护电路包括：并联的高阻抗回路和低阻抗回路,连接在IGBT模块与地之间；检测模块,用于检测所述IGBT模块是否发生短路或过流,并根据检测结果输出控制信号；开关切换模块,用于根据所述控制信号,在所述IGBT模块短路或过流时,将所述IGBT模块接入所述高阻抗回路,在所述IGBT模块正常工作时,将所述IGBT模块接入所述低阻抗回路,以减小流经所述IGBT模块的尖峰电流。本发明提供的技术方案,通过在IGBT模块短路或过流时,将IGBT模块接入高阻抗回路,防止流经IGBT模块的电流急剧减小,进而减小电压尖峰,防止IGBT模块被损坏,延长了IGBT模块的使用寿命。(The invention relates to an IGBT soft turn-off protection circuit, an IGBT driving circuit and electric equipment, wherein the IGBT soft turn-off protection circuit comprises: the high-impedance loop and the low-impedance loop which are connected in parallel are connected between the IGBT module and the ground; the detection module is used for detecting whether the IGBT module is short-circuited or overcurrent or not and outputting a control signal according to a detection result; and the switch switching module is used for switching the IGBT module into the high-impedance loop when the IGBT module is short-circuited or overcurrent according to the control signal, and switching the IGBT module into the low-impedance loop when the IGBT module normally works so as to reduce the peak current flowing through the IGBT module. According to the technical scheme provided by the invention, when the IGBT module is in short circuit or overcurrent, the IGBT module is connected into the high-impedance loop, so that the current flowing through the IGBT module is prevented from being rapidly reduced, the voltage spike is further reduced, the IGBT module is prevented from being damaged, and the service life of the IGBT module is prolonged.)

1. An IGBT soft turn-off protection circuit, comprising:

the high-impedance loop and the low-impedance loop which are connected in parallel are connected between the IGBT module and the ground;

the detection module is used for detecting whether the IGBT module is short-circuited or overcurrent or not and outputting a control signal according to a detection result;

and the switch switching module is used for switching the IGBT module into the high-impedance loop when the IGBT module is short-circuited or overcurrent according to the control signal, and switching the IGBT module into the low-impedance loop when the IGBT module normally works so as to reduce the peak current flowing through the IGBT module.

2. The IGBT soft turn-off protection circuit of claim 1,

the high impedance loop comprises: an inductor, a resistor, or a combination of an inductor and a resistor; and/or the presence of a gas in the gas,

the low impedance loop includes: a switching circuit that is a combination of one or more of the following switching elements, comprising:

bidirectional thyristor, triode, MOS tube.

3. The IGBT soft turn-off protection circuit of claim 1,

if the IGBT module includes a plurality of IGBTs, and each two IGBTs form a phase inverter circuit,

the detection module comprises:

each detection branch is connected with a phase inverter circuit;

and the logic judgment circuit is connected with the detection branch circuit and is used for outputting a control signal according to the detection result of the detection branch circuit.

4. The IGBT soft turn-off protection circuit of claim 3, wherein each of the detection branches comprises:

the anode of the diode is connected with the logic judgment circuit, and the cathode of the diode is connected with the collector of the IGBT;

the constant current source is connected with the anode of the diode;

and the energy storage capacitor is connected with the anode of the diode.

5. The IGBT soft turn-off protection circuit of claim 3, wherein the logic judgment circuit comprises:

the first AND gate is connected with the detection branch circuit and is used for outputting a high-level signal when the upper bridge and the lower bridge of the inverter circuit connected with the first AND gate are in direct short circuit or overcurrent;

the NOR gate is connected with the AND gate and is used for outputting a low-level signal when the upper bridge and the lower bridge of any phase of inverter circuit are subjected to straight-through short circuit or overcurrent;

one end of the second AND gate is connected with the load controller, the other end of the second AND gate is connected with the NOR gate, and the second AND gate is used for outputting a high-level control signal when the load controller and the NOR gate both output high-level signals; the load controller or the NOR gate is also used for outputting a low-level control signal when outputting a low-level signal;

the load controller outputs a high level signal when the IGBT module is started, and outputs a low level signal when the IGBT module is turned off.

6. The IGBT soft turn-off protection circuit according to any one of claims 1 to 5,

the switch switching module is connected with the control end of the low-impedance loop;

the switch switching module is specifically used for conducting when the control signal is a high-level signal, and controlling the low-impedance loop to be conducted so as to connect the low-impedance loop between the IGBT module and the ground; and when the control signal is a low-level signal, the low-impedance loop is cut off, and the low-impedance loop is controlled to be cut off so as to connect the high-impedance loop between the IGBT module and the ground.

7. The IGBT soft turn-off protection circuit of claim 6,

the switch switching module is an optical coupling isolation switch circuit.

8. The IGBT soft turn-off protection circuit of claim 6,

the control end of the low impedance loop is provided with a current limiting resistor with adjustable resistance;

and the current-limiting resistor is used for adjusting the on-off duration of the low-impedance loop.

9. An IGBT driving circuit characterized by comprising:

the IGBT soft turn-off protection circuit of any one of claims 1 to 8.

10. An electrical device, comprising:

the IGBT driver circuit of claim 9.

Technical Field

The invention relates to the technical field of IGBT, in particular to an IGBT soft turn-off protection circuit, an IGBT driving circuit and electric equipment.

Background

An insulated Gate Bipolar transistor (igbt) is a composite fully-controlled voltage-driven power semiconductor device composed of BJT (Bipolar transistor) and MOS (insulated Gate field effect transistor), has the advantages of both high input impedance of MOSFET and low turn-on voltage drop of GTR, and is widely used in the fields of machine tools, robots, and the like.

The IGBT working area is divided into three parts

1. A cut-off region: the voltage between CEs is less than 0.7V, the PN junction on the back of the IGBT is cut off, and no current flows.

2. A saturation area: the inter-CE voltage is greater than 0.7V, current starts to flow, and the inter-CE voltage linearly increases as the collector current increases, which is a desired operating state of the IGBT.

3. An amplification area: as the inter-CE voltage continues to rise, the current further increases. After a certain critical point, the CE voltage increases rapidly without a concomitant increase in collector current. At this time we call that the IGBT exits the saturation region.

In practical application, the desaturation phenomenon generally occurs when a device is short-circuited, at the moment, the CE voltage rises to the bus voltage, the current is generally 4 times of the rated current (see specifications of each device), the power is abnormally increased, the junction temperature rises rapidly, and the device can be burnt out when the device is not turned off in time. Most IGBTs have a certain short circuit tolerance, generally within 10us, and refer to each product specification.

Since the device current is very high in the desaturation state, if the IGBT is turned off without limitation, a large di/dt is generated, a high CE voltage is induced in the parasitic inductance of the loop, and if the voltage is higher than the rated voltage of the device, the IGBT may be damaged.

Fig. 1 shows an IGBT desaturation detection circuit used in the prior art. Referring to fig. 1, when it is detected that the IGBT desaturates, that is, the voltage Va at the point a is greater than the reference voltage Vref, the main control chip MCU turns off the IGBT, and the IGBT is protected by the IGBT desaturation detection circuit. However, since a relatively large voltage spike is generated during turn-off, it is necessary to slow down the turn-off time, which easily damages the IGBT and reduces the service life thereof.

Disclosure of Invention

In view of the above, the present invention provides an IGBT soft turn-off protection circuit, an IGBT driving circuit, and an electric device, so as to solve the problem in the prior art that when an IGBT module is in a short circuit or an overcurrent, a forced turn-off of the IGBT module generates a large voltage spike, which may cause damage to the IGBT module.

According to a first aspect of the embodiments of the present invention, there is provided an IGBT soft turn-off protection circuit, including:

the high-impedance loop and the low-impedance loop which are connected in parallel are connected between the IGBT module and the ground;

the detection module is used for detecting whether the IGBT module is short-circuited or overcurrent or not and outputting a control signal according to a detection result;

and the switch switching module is used for switching the IGBT module into the high-impedance loop when the IGBT module is short-circuited or overcurrent according to the control signal, and switching the IGBT module into the low-impedance loop when the IGBT module normally works so as to reduce the peak current flowing through the IGBT module.

Preferably, the high impedance loop comprises: an inductor, a resistor, or a combination of an inductor and a resistor; and/or the presence of a gas in the gas,

the low impedance loop includes: a switching circuit that is a combination of one or more of the following switching elements, comprising:

bidirectional thyristor, triode, MOS tube.

Preferably, if the IGBT module includes a plurality of IGBTs, and every two IGBTs form a phase inverter circuit,

the detection module comprises:

each detection branch is connected with a phase inverter circuit;

and the logic judgment circuit is connected with the detection branch circuit and is used for outputting a control signal according to the detection result of the detection branch circuit.

Preferably, each of the detection branches comprises:

the anode of the diode is connected with the logic judgment circuit, and the cathode of the diode is connected with the collector of the IGBT;

the constant current source is connected with the anode of the diode;

and the energy storage capacitor is connected with the anode of the diode.

Preferably, the logic determination circuit includes:

the first AND gate is connected with the detection branch circuit and is used for outputting a high-level signal when the upper bridge and the lower bridge of the inverter circuit connected with the first AND gate are in direct short circuit or overcurrent;

the NOR gate is connected with the AND gate and is used for outputting a low-level signal when the upper bridge and the lower bridge of any phase of inverter circuit are subjected to straight-through short circuit or overcurrent;

one end of the second AND gate is connected with the load controller, the other end of the second AND gate is connected with the NOR gate, and the second AND gate is used for outputting a high-level control signal when the load controller and the NOR gate both output high-level signals; the load controller or the NOR gate is also used for outputting a low-level control signal when outputting a low-level signal;

the load controller outputs a high level signal when the IGBT module is started, and outputs a low level signal when the IGBT module is turned off.

Preferably, the switch switching module is connected with the control end of the low impedance loop;

the switch switching module is specifically used for conducting when the control signal is a high-level signal, and controlling the low-impedance loop to be conducted so as to connect the low-impedance loop between the IGBT module and the ground; and when the control signal is a low-level signal, the low-impedance loop is cut off, and the low-impedance loop is controlled to be cut off so as to connect the high-impedance loop between the IGBT module and the ground.

Preferably, the switch switching module is an optical coupling isolation switch circuit.

Preferably, the control end of the low impedance loop is provided with a current limiting resistor with adjustable resistance;

and the current-limiting resistor is used for adjusting the on-off duration of the low-impedance loop.

According to a second aspect of the embodiments of the present invention, there is provided an IGBT driving circuit including:

the IGBT soft turn-off protection circuit is described above.

According to a third aspect of embodiments of the present invention, there is provided an electric device, including:

the IGBT driving circuit is described above.

The technical scheme provided by the embodiment of the invention can have the following beneficial effects:

through when the IGBT module short circuit or overcurrent, insert the high impedance return circuit with the IGBT module, prevent that the electric current that flows through the IGBT module from sharply reducing, and then reduce the voltage spike, prevent that the IGBT module from being damaged, prolonged the life of IGBT module.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a circuit schematic diagram of an IGBT desaturation detection circuit according to the background art;

FIG. 2 is a functional block diagram of an IGBT soft turn-off protection circuit shown in accordance with an exemplary embodiment;

3A-3B are circuit schematics of a detection branch according to an exemplary embodiment;

fig. 4 is a flowchart illustrating a control method of the IGBT soft turn-off protection circuit according to an exemplary embodiment.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the invention, as detailed in the appended claims.

Example one

Fig. 2 is a circuit schematic diagram illustrating an IGBT soft turn-off protection circuit according to an exemplary embodiment, as shown in fig. 2, the circuit including:

the high-impedance loop 11 and the low-impedance loop 12 which are connected in parallel are connected between an IGBT module (for example, the IGBT module consists of six IGBTs in figure 2, and comprises G1-G6) and the ground;

the detection module 13 is used for detecting whether the IGBT module is short-circuited or overcurrent or not and outputting a control signal according to a detection result;

and the switch switching module 14 is used for switching the IGBT module into the high-impedance loop 11 when the IGBT module is short-circuited or overcurrent according to the control signal, and switching the IGBT module into the low-impedance loop 12 when the IGBT module normally works so as to reduce the peak current flowing through the IGBT module.

It can be understood that, according to the technical scheme provided by this embodiment, when the IGBT module is short-circuited or overcurrent, the IGBT module is connected to the high impedance loop, so that the current flowing through the IGBT module is prevented from being sharply reduced, and further, the voltage spike is reduced, the IGBT module is prevented from being damaged, and the service life of the IGBT module is prolonged.

In the turn-off process of the IGBT module, if the turn-off time required by the IGBT module is directly reduced, the peak voltage is overlarge, if the IGBT module is switched to a high-impedance loop, the current cannot be rapidly reduced, but the current starts to be reduced at the moment of detecting the short circuit of the IGBT module, and after the IGBT module is rapidly turned off, the current is reduced by a large part, so that the current reduction speed is reduced, and the voltage peak is further reduced.

It is understood that when the IGBT module is short-circuited or over-current, the current flowing through the IGBT module may be large. The IGBT module generally has an overcurrent time, the more the current exceeds the maximum current which can be borne by the IGBT module, the shorter the time, the IGBT module can be damaged after the time, and the IGBT is easily burnt out after the IGBT is in an overcurrent state for a long time due to the long turn-off time.

Controlling the turn-off time is typically done by varying the gate resistance of the IGBT module, and reducing the gate resistance can reduce the turn-off time. However, since the current is instantaneously reduced at this time, a large voltage spike is generated, and if the voltage exceeds the withstand voltage of the IGBT module, the IGBT module may be damaged, and therefore, the turn-off time cannot be too short.

According to the technical scheme provided by the embodiment, when the IGBT module is in a short circuit or an overcurrent, the IGBT module is connected into the high-impedance loop, and the current flowing through the IGBT module cannot be rapidly reduced, so that shorter turn-off time can be adopted, and the problem that the IGBT module is damaged due to overlong turn-off time is solved while the voltage spike is ensured to be reduced.

In particular practice, the high impedance loop 11 may comprise: an inductor, a resistor, or a combination of an inductor and a resistor; and/or the presence of a gas in the gas,

the low impedance loop 12 may include: a switching circuit that is a combination of one or more of the following switching elements, comprising:

bidirectional thyristor, triode, MOS tube.

If the IGBT module includes a plurality of IGBTs, and each two IGBTs form a phase inverter circuit,

the detection module 13 includes:

at least one detection branch 131, wherein each detection branch 131 is connected with a phase inverter circuit;

and the logic judgment circuit 132 is connected to the detection branch 131, and is configured to output a control signal according to a detection result of the detection branch 131.

Referring to fig. 2, the IGBT module is a three-phase bridge inverter module, and includes six IGBTs (e.g., G1 to G6 in fig. 2);

every two IGBTs form a phase inverter circuit for providing a phase AC input for the load motor M.

The detection module 13 includes:

six detection branches 131, each detection branch 131 is connected with one phase inverter circuit;

and the logic judgment circuit 132 is connected to the detection branch 131, and is configured to output a control signal according to a detection result of the detection branch 131.

Referring to fig. 3A to 3B, each detection branch 131 includes: :

a diode D1, the anode of which is connected to the logic judgment circuit 132 and the cathode of which is connected to the collector of the IGBT G1;

the constant current source DC is connected with the anode of the diode D1;

and the energy storage capacitor C1 is connected with the anode of the diode D1.

Referring to fig. 3A, fig. 3A is a diagram illustrating a current trend of the detection branch when G1 is operating normally. When G1 works normally, the diode D1 is conducted, the current output by the constant current source DC flows into the ground through D1 and G1, and the detection branch outputs a low-level signal through the diode D1;

referring to fig. 3B, fig. 3B is a diagram illustrating a current trend of the detection branch when G1 is short-circuited or overcurrent. At this time, the voltage value of the cathode of the diode D1 is extremely large, a forward voltage drop cannot be formed between the anode and the cathode of the diode D1, and the diode D1 is cut off, the current output by the constant current source DC charges the capacitor, and in the process of charging the capacitor, the voltage of the anode of the diode D1 is increased, and the detection branch outputs a high-level signal.

Referring to fig. 2, preferably, the logic determining circuit 132 includes:

the first AND gate is connected with the detection branch circuit and is used for outputting a high-level signal when the upper bridge and the lower bridge of the inverter circuit connected with the first AND gate are in direct short circuit or overcurrent;

the NOR gate is connected with the AND gate and is used for outputting a low-level signal when the upper bridge and the lower bridge of any phase of inverter circuit are subjected to straight-through short circuit or overcurrent;

one end of the second AND gate is connected with the load controller, the other end of the second AND gate is connected with the NOR gate, and the second AND gate is used for outputting a high-level control signal when the load controller and the NOR gate both output high-level signals; the load controller or the NOR gate is also used for outputting a low-level control signal when outputting a low-level signal;

the load controller outputs a high level signal when the IGBT module is started, and outputs a low level signal when the IGBT module is turned off.

Referring to fig. 2, the diodes of the first detection branch are D1 and D4, the diodes of the second detection branch are D2 and D5, and the diodes of the third detection circuit are D3 and D6.

When the IGBT module works normally, only one of the two IGBTs in the one-phase inverter circuit is switched on, and the other IGBT is switched off. Assuming normal operation, G1 in FIG. 2 is turned on and G4 is turned off; g5 is turned on, G2 is turned off; g6 is conducted, G3 is cut off, a diode D1 is conducted, current of a constant current source (not shown in FIG. 2, see constant source DC of FIG. 3) passes through D1 and then sequentially flows through G1, a load motor and G6 to the ground, and IGBT voltage drop is low; when the G2 is desaturated, the G1 and the G4 form a path, the voltage drop increases sharply, the D1 and the D4 are cut off, the current output by the constant current source (not shown in fig. 2) of the first detection branch can only charge the energy storage capacitor (not shown in fig. 2, see the energy storage capacitor C1 in fig. 3), and when the voltage on the energy storage capacitor exceeds a threshold value, a high level signal is sent to the and gate connected to the first detection branch, which indicates that a through short circuit or an overcurrent occurs in the upper bridge and the lower bridge of the inverter circuit of the current phase.

The detection principle of whether short circuit or overcurrent occurs in the inverter circuits of other phases is the same, and is not described herein again.

In particular practice, the switching module 14 is connected to the control terminal of the low impedance loop 12;

the switch switching module 14 is specifically configured to be turned on when the control signal is a high level signal, and control the low impedance loop 12 to be turned on, so as to connect the low impedance loop 12 between the IGBT module and ground; and when the control signal is a low-level signal, the low-impedance loop 12 is cut off, so that the high-impedance loop 11 is connected between the IGBT module and the ground.

In a specific practice, the control end of the low impedance loop 12 is provided with a current limiting resistor (not shown in the drawing) with an adjustable resistance;

the current limiting resistor is used for adjusting the on-off duration of the low impedance loop 12.

Taking the low impedance loop 12 as an example of a triac, increasing the turn-off current of the triac can be changed by changing the magnitude of the gate-level resistance of the triac, and decreasing the resistance increases the current. When the turn-off current is increased, the PN junction between the gate level of the bidirectional controllable silicon and the ground is turned off more quickly, and then the whole bidirectional controllable silicon is turned off more quickly.

Referring to fig. 2, the switch switching module 14 is preferably an optical coupling isolation switch circuit.

It can be understood that the optical coupling isolating switch circuit can improve the anti-interference capability of the circuit and improve the reliability and stability of the circuit.

Fig. 4 is a flowchart illustrating a control method of an IGBT soft turn-off protection circuit according to an exemplary embodiment, as shown in fig. 4, the method includes:

when the load controller MCU outputs a high level signal OE 1 when starting the IGBT module, when the IGBT module normally works, the NOR gate outputs a high level control signal Y4 1, and at the moment, OE 1 and Y4 1 are met, the detection module outputs a high level control signal, the optical coupling isolating switch circuit is switched on, the bidirectional thyristor is switched on, the high impedance loop is short-circuited, and the low impedance loop is switched in between the IGBT module and the ground.

When the load controller MCU starts the IGBT module, the load controller MCU outputs a high level signal OE (zero-order) 1, when the IGBT module is short-circuited or overcurrent occurs, the NOR gate outputs a low level control signal Y4 which is 0, at the moment, the detection module outputs a low level control signal, the optical coupling isolating switch circuit is not conducted, the bidirectional thyristor is not conducted, and the high impedance loop is connected between the IGBT module and the ground; subsequently, the load controller MCU turns off the IGBT module, outputs a low level signal OE (zero-crossing) 0, the optical coupling isolating switch circuit is not conducted, the bidirectional controllable silicon is not conducted, and when the load controller MCU restarts the IGBT module, OE 1 and Y4 1, the low-impedance loop is connected between the IGBT module and the ground again, otherwise, the high-impedance loop is connected between the IGBT module and the ground all the time, so that the IGBT module can be better protected.

It can be understood that, according to the technical scheme provided by this embodiment, when the IGBT module is short-circuited or overcurrent, the IGBT module is connected to the high impedance loop, so that the current flowing through the IGBT module is prevented from being sharply reduced, and further, the voltage spike is reduced, the IGBT module is prevented from being damaged, and the service life of the IGBT module is prolonged.

Example two

An IGBT driving circuit according to an exemplary embodiment is shown, including:

the IGBT soft turn-off protection circuit is described above.

It can be understood that, according to the technical scheme provided by this embodiment, since the IGBT soft turn-off protection circuit is included, when the IGBT module is short-circuited or overcurrent, the IGBT module is connected to the high impedance loop by the IGBT soft turn-off protection circuit, so that the current flowing through the IGBT module is prevented from being sharply reduced, and thus, the voltage spike is reduced, the IGBT module is prevented from being damaged, and the service life of the IGBT module is prolonged.

EXAMPLE III

An electrical device is shown according to an exemplary embodiment, comprising:

the IGBT driving circuit is described above.

It can be understood that, according to the technical scheme provided by this embodiment, since the IGBT soft turn-off protection circuit is included, when the IGBT module is short-circuited or overcurrent, the IGBT module is connected to the high impedance loop by the IGBT soft turn-off protection circuit, so that the current flowing through the IGBT module is prevented from being sharply reduced, and thus, the voltage spike is reduced, the IGBT module is prevented from being damaged, and the service life of the IGBT module is prolonged.

It is understood that the same or similar parts in the above embodiments may be mutually referred to, and the same or similar parts in other embodiments may be referred to for the content which is not described in detail in some embodiments.

It should be noted that the terms "first," "second," and the like in the description of the present invention are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Further, in the description of the present invention, the meaning of "a plurality" means at least two unless otherwise specified.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and alternate implementations are included within the scope of the preferred embodiment of the present invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present invention.

It should be understood that portions of the present invention may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.

It will be understood by those skilled in the art that all or part of the steps carried by the method for implementing the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer readable storage medium, and when the program is executed, the program includes one or a combination of the steps of the method embodiments.

In addition, functional units in the embodiments of the present invention may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may also be stored in a computer readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.