阅读说明：本技术 功率器件的驱动装置与方法 (Driving device and method of power device ) 是由 陈劲泉 倪川 陆玮 于 2020-02-17 设计创作，主要内容包括：本申请提供了一种功率器件驱动装置,包括检测模块,与功率器件耦合,配置为检测功率器件状态；驱动模块,分别耦合至所述检测模块和功率器件,配置为根据所述检测模块的检测结果对所述功率器件进行调控；其中,所述检测模块包括快速检测子模块,配置为当所述驱动装置的输入信号无效后的预设时间段内对功率器件状态进行检测,并在功率器件存在过流的情况下控制所述驱动模块对功率器件进行软关断。本申请还提供了相应的功率器件驱动方法和用电设备。(The application provides a power device driving device, which comprises a detection module, a driving module and a control module, wherein the detection module is coupled with a power device and configured to detect the state of the power device; the driving module is respectively coupled to the detection module and the power device and is configured to regulate and control the power device according to the detection result of the detection module; the detection module comprises a quick detection submodule and is configured to detect the state of the power device within a preset time period after an input signal of the driving device is invalid, and control the driving module to perform soft turn-off on the power device under the condition that the power device has overcurrent. The application also provides a corresponding power device driving method and electric equipment.)

1. A power device driving apparatus comprising:

a detection module coupled with the power device and configured to detect a state of the power device;

the driving module is respectively coupled to the detection module and the power device and is configured to regulate and control the power device according to the detection result of the detection module;

the detection module comprises a quick detection submodule and is configured to detect the state of the power device within a preset time period after an input signal of the driving device is invalid, and control the driving module to perform soft turn-off on the power device under the condition that the power device has overcurrent.

2. The driving apparatus of claim 1, wherein the detection module further comprises a filtering sub-module configured to detect a state of a power device when the input signal is active.

3. The driving apparatus of claim 1 or 2, wherein the detection module further comprises a current source coupled between a power supply and a first node in the fast detection submodule; and an OR gate coupled between the detection module and the driving module and configured to provide a control signal to the driving module according to outputs of the fast detection sub-module and the filtering sub-module.

4. The drive arrangement of claim 3, wherein the fast detection submodule comprises

A first comparator having a first input coupled to the first node and the first pole of the power device, a second input configured to receive a first threshold signal, and an output coupled to the OR gate;

a first switch coupled between the first node and the filtering submodule and configured to disconnect the coupling of the filtering submodule and the power device when the input signal is inactive and during the preset time period.

5. The drive apparatus of claim 3, wherein the filter submodule comprises

A second node coupled to the first node through the first switch and to ground potential through a second switch;

a second comparator having a first input coupled to the second node, a second input configured to receive a second threshold signal, and an output coupled to the OR gate; and

a capacitance coupled between the second node and a ground potential.

6. The driving apparatus of claim 4, further comprising a coupling diode having an anode coupled to the fast detection submodule and a cathode coupled to a first pole of a power device.

7. The drive device according to claim 1, wherein the preset time period is 100 nanoseconds or less.

8. The driving apparatus as claimed in claim 4, wherein the fast detection module further comprises a control unit configured to operate the fast detection module only for the preset time period or output the comparison result of the first comparator.

9. A driving method for a power device, comprising:

determining whether an input signal of the power device driving apparatus is valid;

when the input signal is invalid, determining whether the input signal is in a preset time period within the invalid time, wherein the preset time period is calculated from the invalid time of the input signal;

when the input signal failure time is within a preset time period, detecting the state of a power device by using a non-filtering means and determining whether overcurrent exists or not;

and when overcurrent exists, the power device is turned off in a soft mode.

10. The method of claim 9, further comprising

And when the input signal failure time exceeds a preset time period, the power device is turned off hard.

11. The method of claim 9, further comprising

When the input signal is valid, the state of the power device is detected at least by using a filtering means.

12. The method of any of claims 9-11, wherein the preset time period is equal to or less than 100 nanoseconds.

13. An electrical device comprising:

one or more power devices; and

the driving apparatus of one or more of claims 1 to 8, coupled to a respective power device to provide a driving signal to the power device.

Technical Field

The application belongs to the field of electrical control, and particularly relates to a driving device and a driving method suitable for a power device.

Background

Power devices such as Insulated Gate Bipolar Transistors (IGBTs) have been widely used in the fields of motor drives, lighting circuits, frequency converters, traction drives, and the like for many years. In practical applications, however, a short circuit of the load often occurs. Under the condition of short circuit of a load, the on-current of the IGBT is very high, and if the power device is not turned off in time, the device is overheated, and finally the device is damaged.

When the load is short-circuited and the overcurrent work is to be cut offWhen the power device (such as IGBT) is used, V may be caused if the driving capability of the normal turn-off is adopted_CEIs too large, thereby damaging the power device. Therefore, when the over-current device is turned off, soft turn-off is generally adopted, that is, the driving voltage of a power device such as an IGBT transistor is reduced, and the driving capability of a power device driving circuit is reduced to reduce V_CEThe voltage of (c). The system or the user can set a waiting time after the soft-off of the power device according to the requirement so as to dissipate the heat generated by the overcurrent or wait for the reason of the overcurrent to disappear. And within the waiting time, the power device with the overcurrent cannot be turned on, and after the waiting time is over, the power device resumes normal operation again. Since the power device generally enters a saturation operating region when the load is short-circuited, this protection mode of entering soft turn-off while waiting for a period of time is called DESAT (DESAT). Generally, a filter is used to implement the above-mentioned deputy protection.

Fig. 1 is a block diagram of a conventional power device driving apparatus. As can be seen, the general driving device adopts the voltage V of the filter to the power device_CEAnd monitoring, and if an overcurrent condition is found, jumping the soft off signal SOFF to be effective so as to enable the power device to enter a soft off mode through the driving module.

Disclosure of Invention

The present application is directed to the above-mentioned problem, and provides a power device driving apparatus, including a detection module, coupled to a power device, and configured to detect a state of the power device; the driving module is respectively coupled to the detection module and the power device and is configured to regulate and control the power device according to the detection result of the detection module; the detection module comprises a quick detection submodule and is configured to detect the state of the power device within a preset time period after an input signal of the driving device is invalid, and control the driving module to perform soft turn-off on the power device under the condition that the power device has overcurrent.

In particular, the detection module further comprises a filtering submodule configured to detect a state of the power device when the input signal is valid.

In particular, the detection module further comprises a current source coupled between a power supply and a first node in the fast detection submodule; and an OR gate coupled between the detection module and the driving module and configured to provide a control signal to the driving module according to outputs of the fast detection sub-module and the filtering sub-module.

In particular, the fast detection submodule comprises a first comparator having a first input coupled to the first node and to the first pole of the power device and having a second input configured to receive a first threshold signal; the fast detection sub-module further includes a first switch coupled between the first node and the filtering sub-module and configured to disconnect the coupling of the filtering sub-module and the power device when the input signal is inactive and during the preset time period.

In particular, the filtering submodule comprises a second node coupled to the first node through the first switch and to ground potential through a second switch; a second comparator having a first input coupled to the second node and a second input configured to receive a second threshold signal; and a capacitance coupled between the second node and ground potential.

In particular, the driving device further comprises a coupling diode, an anode of the coupling diode is coupled to the fast detection submodule, and a cathode of the coupling diode is coupled to the first pole of the power device.

In particular, the preset time period is less than or equal to 100 nanoseconds.

In particular, the fast detection module further comprises a control unit configured to enable the fast detection module to work only within the preset time period or output the comparison result of the first comparator.

The present application also provides a driving method for a power device, including determining whether an input signal of a power device driving apparatus is valid; when the input signal fails, determining whether the input signal failure time is within a preset time period; when the input signal failure time is within a preset time period, detecting the state of a power device by using a non-filtering means and determining whether overcurrent exists or not; and when overcurrent exists, the power device is turned off in a soft mode.

In particular, the method further comprises the step of turning off the power device in a hard mode when the input signal failure time exceeds a preset time period.

In particular, the method further comprises detecting the state of the power device by at least using the filtering means when the input signal is valid.

Specifically, in the aforementioned method, the preset time period is 100 nanoseconds or less.

The application also provides an electric device, which comprises one or more power devices; and one or more of the aforementioned drive means coupled to a respective power device to provide a drive signal thereto.

By adopting the technical scheme provided by the application, the overcurrent phenomenon of the power device in the preset time period when the input signal of the driving device becomes invalid can be captured more accurately, the power device is turned off softly in time, and the condition that the device is damaged due to the fact that the power device is turned off hardly in the time period is avoided.

Drawings

Embodiments are shown and described with reference to the drawings. These drawings are provided to illustrate the basic principles and thus only show the aspects necessary for understanding the basic principles. The figures are not to scale. In the drawings, like reference numerals designate similar features.

Fig. 1 is a schematic diagram of a conventional power device driving apparatus;

FIG. 2 is a diagram of a power device driver architecture according to one embodiment of the present application;

fig. 3 is a schematic circuit diagram of a power device driving apparatus according to an embodiment of the present application;

FIG. 4 is a flow chart of a power device driving method according to an embodiment of the present application; and

fig. 5 is a timing diagram of the power device driving apparatus of fig. 3.

Detailed Description

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings, which form a part hereof. The accompanying drawings illustrate, by way of example, specific embodiments in which the present application can be practiced. The illustrated embodiments are not intended to be exhaustive of all embodiments according to the application. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present application. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present application is defined by the appended claims.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. For the connection between the units in the drawings, for convenience of description only, it means that at least the units at both ends of the connection are in communication with each other, and is not intended to limit the inability of communication between the units that are not connected.

In the following detailed description, reference is made to the accompanying drawings that form a part hereof and in which is shown by way of illustration specific embodiments of the application. In the drawings, like numerals describe substantially similar components throughout the different views. Various specific embodiments of the present application are described in sufficient detail below to enable those skilled in the art to practice the teachings of the present application. It is to be understood that other embodiments may be utilized and structural, logical or electrical changes may be made to the embodiments of the present application.

Generally, when an input signal of a power device driving circuit jumps from an active level to an inactive level, the driving circuit rapidly turns off the power device. If an overcurrent occurs before the overcurrent is turned off, the time constant of the filter in the overcurrent monitoring circuit is relatively long (e.g., 1 microsecond) or takes a relatively long time to detect whether an overcurrent phenomenon exists. If the overcurrent actually occurs but is not detected at this time, and the power device is turned off hard, the power device may be damaged.

In order to solve the above problems, the present application provides a dual-mode overcurrent protection method. Can monitor V when the input signal is effective_CEAnd can also be used for V within a preset time after the input signal fails_CEAnd carrying out quick detection, and switching to soft turn-off of the power device when overcurrent occurs so as to avoid overvoltage damage of the power device. In the following description, a high level is exemplified as an active level and a low level is exemplified as an inactive level. According to one embodiment, the active level of the input signal represents an instruction to turn the power device on and the inactive level of the input signal represents an instruction to turn the power device off.

Fig. 2 is an architecture diagram of a driving device according to an embodiment of the present application.

As shown, the power device driving apparatus 200 is coupled to a power device to provide a driving signal to the power device. According to one embodiment, the driving device 200 may include a detection module 202 and a driving module 204. The detection module 202 may be used to detect the state of the power device (e.g., an IGBT transistor) to generate and provide a corresponding state signal (e.g., a soft off signal SOFF) to the drive module 204 based on the state of the power device. Based on the above configuration, the driving module 204 may drive the power device based on the status signal from the detection module 202.

According to an embodiment, the detection module 202 may include a fast detection sub-module 2022, which may perform fast detection on the power device within a preset time period after the transition of the driving module input signal IN to the inactive signal, and perform soft shutdown on the power device once the overcurrent is found. After the preset time has elapsed, the power device may be hard turned off if the input signal IN is still IN an inactive state.

According to another embodiment, the detection module 202 may further include a conventional filtering sub-module 2024 for determining an over-current condition when the input signal IN is active and deciding whether to soft-switch off the power device.

Hereinafter, the power device is an IGBT transistor, and the state signal is the voltage V of the IGBT transistor_CEBy way of exampleAre set forth. Of course, it will be understood by those skilled in the art that the solution of the present application can be applied to other types of power devices or other status signals (e.g., current, etc.).

Fig. 3 is a circuit diagram of a driving device according to an embodiment of the present application. As shown, the driving apparatus 200 may include a driving module 204 coupled to a control electrode G of a power device, such as an IGBT transistor, to provide a driving signal to the power device. According to one embodiment, the driving device 200 may further include a detection module 202. According to an embodiment, the driving apparatus 200 may further include a diode 206 having an anode coupled to the input terminal of the detection module 202 and a cathode coupled to the first electrode C of the IGBT transistor. When the IGBT transistor is conducted and the VCE voltage is lower, the diode 206 is conducted in the forward direction, and the voltage V can be indirectly obtained at the node A of the detection end_CEThereby indirectly detecting the on-current of the IGBT; when V is_CEWhen the voltage is high (for example, when the IGBT transistor is turned off or a large current short circuit occurs), the diode 206 is turned off to ensure the voltage V at the node a of the detection terminal_CESNo overpressure occurs.

According to one embodiment, detection module 202 may include a fast detection sub-module 2022 and a filtering sub-module 2024. According to one embodiment, detection module 202 further includes a current source 2026 coupled between the power supply and fast detection sub-module 2022. The detection module may further comprise an or gate 2028 having an input coupled to the outputs of the fast detection sub-module 2022 and the filtering sub-module 2024 and an output coupled to one input of the driver module 204 to provide the soft off control signal SOFF.

According to one embodiment, the fast detection sub-module 2022 may include a comparator 20222 having a positive input receiving the AND V_CEVoltage V at node a of interest_CES(e.g. V)_CES＝V_CE+V_thd,V_thdWhich may be the threshold voltage of diode 206), node a is coupled to the anode of diode 206 and the positive input of comparator 20222 and current source 2026. The negative input terminal of the comparator 20222 receives a reference voltage V_FOC. An output of the comparator 20222 is coupled to an input of an or gate 2028.

According to one embodiment, the filtering sub-module 2024 may include a capacitor C1 and a comparator 20242, one end of the capacitor C1 being coupled to ground potential and the other end being coupled to the positive input of the comparator 20242. The negative input of comparator 20242 may be used to receive V_DESAT. Of course, there are various configurations of the filtering sub-modules in the art, and those skilled in the art can replace the configuration of the filtering sub-module in fig. 3 without any inventive effort. V_DESATAnd V_FOCDifferent thresholds can be selected, e.g. V for interference rejection_FOCIs set to be greater than V_DESAT(ii) a For another example, when the space reserved by the user for withstanding the voltage of the power device is relatively small, V_FOCCan be set to be less than V_DESATTo ensure that overvoltage at turn-off does not damage the power device.

According to one embodiment, node a in the fast detection submodule 2022 is coupled to node B in the filtering submodule 2024 and the positive input of the comparator 20242 through a switch T1 controlled by a signal S2. According to one embodiment, node B is coupled to ground through switch T2, which is controlled by signal S1.

According to one embodiment, the fast detection sub-module 2022 may further comprise an not gate 20224 and an and gate 20226 configured to receive the signal S2, the and gate 20226 is configured to receive the output of the not gate 20224 and the output of the comparator 20222, and the output of the and gate 20226 may be the FOC-FLAG together with the output DESAT-FLAG of the filter 2024 as the input of the or gate 2026. Thus, referring to fig. 5, when S2 is low, i.e. the input signal IN transitions to the disable signal, the output of the not gate 20224 is high, so that the output FOC-FLAG of the and gate 20226 is the output of the comparator 20222 during the predetermined period; at times other than this preset time period, S2 is high, so the output of not gate 20224 is low, and the output FOC-FLAG of and gate 20226 is also low.

According to other embodiments, the fast detection sub-module 2022 may include other units for controlling the operation state of the fast sub-module 2022, for example, the comparator 20222 may be controlled to operate only IN a preset time period after the input signal IN transitions to the inactive signal, and to be inactive IN other time periods.

Fig. 4 is a flow chart of a power device driving method according to an embodiment of the present application. Fig. 5 is a timing diagram illustrating an operation of a power device driving apparatus according to an embodiment of the present application.

According to one embodiment, an input signal IN of the power device driving apparatus may be detected at step 402, and it is determined whether the input signal IN is valid at step 404. The purpose of this operation is primarily to decide whether the fast detection sub-module should be enabled or whether the power device should be detected using the normal filtering sub-module.

IN the case where the input signal IN is at an active level, such as the high level shown IN FIG. 5, the general detection mode is applied to the status signal representative of the power device, such as V for IGBT transistors, at step 406_CEAnd (6) detecting. The general detection mode may be implemented by, for example, a filtering sub-module according to one embodiment.

When the result of the general detection mode is that the power device has an overcurrent condition, the step 420 is skipped to, and the power device is turned off in a soft manner.

When the result of the general detection mode is that the power device does not have an overcurrent condition, the detection is ended, or the step 402 is skipped to continue detecting the input signal IN at the next moment.

When the input signal IN is IN the inactive state as a result of the step 404, it is determined whether the time during which the input signal IN is IN the inactive state is still within the preset time period IN the step 410. According to one embodiment, this preset time period may be a relatively short time, such as 100 nanoseconds or less.

When the time that the input signal IN is IN the inactive state has exceeded the preset time period, the power device may be turned off hard at step 416.

When the time when the input signal IN is IN the inactive state is still within the preset time period, the fast detection mode is entered IN step 412, and it is determined whether the power device has an overcurrent condition IN step 414, and the method jumps to step 420 to perform soft shutdown on the device IN the case that the power device has an overcurrent condition, and jumps back to step 402 to detect the input signal IN at the next moment IN the case that the power device has no overcurrent condition.

Fig. 5 is a timing chart showing the operation of the power device driving apparatus of fig. 3.

(1) Before time T1

Before and including this stage, the input signal VIN is always at an active level, e.g., high level, so that the switch S2 is turned on, the switch S1 is turned off, the capacitor C1 is charged, and the connection potentials at the node a and the node B are both V_CES. In this phase the IGBT transistor is in the conducting state, V_CEAt very low voltage, diode 206 conducts so that V_CESIs approximately V_CEAnd therefore also belongs to the low state.

(2) Period T1-T2

From time T1, V_CEThe gradual rise of the working potential indicates that the power device begins to generate an overcurrent phenomenon. But in this period, represents V_CEVoltage V of_CESIs always less than V_FOCAnd V_DESATAnd the overcurrent condition of the power device is shown to be in a tolerable range. Therefore, at this stage, the inputs FOC-FLAG and DEASAT-FLAT of the OR gate 2028 are both low, and the output SOFF of the OR gate 2028 is also low.

(3) Period T2-T3

At time T2, the input signal IN of the driver transitions from an active high level to an inactive low level. At time T2, switch S2 is open, switch S1 remains open, and the fast detection submodule begins operating.

At this stage, even V_CEContinuously rises, the voltage V at the node B is generated due to the opening of the switch S2 and the existence of the capacitor C1_C1Remains unchanged and is always less than V_DESAT。

In contrast, the potential V at the node A_CESWith V_CEContinuously rises and exceeds V at the time of TX_FOC. Thus, at the time of TX, the output of the comparator in the fast detection submodule transitions from a low potential to a high potential. Therefore, the output signal SOFF of the or gate also jumps to a high potential at time TX. The power device is soft-off at the time of TX.

(3) After time T3

After time T3, the power device may be turned off hard, so the voltage GATE of the power device, e.g., the GATE of the IGBT, also gradually drops from a high level to a low level. Thus, V_CESAnd V_C1Is pulled down to a low level at this time.

At time T3, switch S2 is turned on and switch S1 is also turned on, thereby discharging capacitor C1. The switch S1 functions to discharge the capacitor C1 when the IGBT transistor is turned off, thereby resetting the filter submodule.

According to various embodiments, the over-current condition of the power device may be represented by different parameters. For example, by detecting the V of a power device, such as an IGBT transistor, it can be assumed that the on-resistance of the power device is a fixed value_CEThe over-current condition of the power device can be known. Of course, for other power devices, a current level detection means may be provided. For such a power device, the overcurrent state can be determined by directly detecting the level of the current thereof. The methods and apparatus provided herein are not only applicable to pass through V_CEThe method is also suitable for representing the overcurrent state of the power device by using other indexes. That is, the threshold corresponding to the state of the power device in this application may be a voltage, a current, or the like.

By adopting the circuit and the method, not only can general overcurrent and desaturation overcurrent conditions be distinguished, so that corresponding protection modes can be selected in a targeted mode, but also the monitoring time is prolonged, the monitoring is continued for a period of time after the general overcurrent phenomenon is found, and corresponding protection measures are taken immediately if the desaturation overcurrent phenomenon is found. Because the probability of desaturation and overcurrent after the general overcurrent phenomenon occurs is higher, the desaturation and overcurrent phenomenon can be captured more timely and accurately by adopting the scheme in the embodiment, and timely and effective protection is applied to the power device.

By adopting the technical scheme, compared with the traditional detection method adopting a filtering method, the overcurrent phenomenon of the power device in the preset time period when the input signal of the driving device becomes invalid can be captured more accurately, the power device is turned off softly in time, and the condition that the device is damaged due to the fact that the power device is turned off hardly in the time period is avoided.

Thus, while the present application has been described with reference to specific examples, which are intended to be illustrative only and not to be limiting of the application, it will be apparent to those of ordinary skill in the art that changes, additions or deletions may be made to the disclosed embodiments without departing from the spirit and scope of the application.