CN211981789U

CN211981789U - Drive circuit and switch module

Info

Publication number: CN211981789U
Application number: CN202020655570.5U
Authority: CN
Inventors: 王立新
Original assignee: Beijing Iwitech Automotive Technology Co ltd
Current assignee: Beijing Iwitech Automotive Technology Co ltd
Priority date: 2020-04-26
Filing date: 2020-04-26
Publication date: 2020-11-20
Anticipated expiration: 2030-04-26

Abstract

The application provides a drive circuit and switch module, drive circuit includes: the half-bridge driving circuit comprises a half-bridge driving unit, a plurality of transformers and a rectifying and filtering unit corresponding to each transformer; wherein, the primary sides of a plurality of transformers are connected in parallel; the input end of the half-bridge driving unit is connected with an external power supply, and the external power supply is used for supplying power to the half-bridge driving unit; the output end of the half-bridge driving unit is connected with the primary sides of the plurality of transformers, and the half-bridge driving unit is used for controlling the input voltage of the primary side of each transformer; the secondary side of each transformer is connected with the corresponding rectifying and filtering unit, and the transformer is used for isolating the rectifying and filtering unit corresponding to the transformer from the rectifying and filtering units corresponding to other transformers; the rectifying and filtering unit is also connected with the power electronic switching elements and is used for providing direct current for the corresponding power electronic switching elements so as to ensure that each power supply has proper creepage distance and electrical clearance.

Description

Drive circuit and switch module

Technical Field

The application relates to the field of electric drive, in particular to a drive circuit and a switch module.

Background

A motor controller is one of the cores of a drive control system of a pure electric vehicle, and a relatively important switch module in the motor controller generally needs a special drive circuit, for example, in the field of electric vehicles, an Insulated Gate Bipolar Transistor (IGBT) which is the most widely used power electronic switch element is generally required to provide a plurality of isolated power supplies for each IGBT through a power drive circuit in order to ensure the working consistency of the plurality of IGBTs.

In a conventional power driving circuit in a switch module, a plurality of power supplies isolated from each other can be collectively produced by a single transformer, and each power supply supplies power to one power electronic switch element. However, creepage distances and electrical gaps between a plurality of power supplies produced by the same transformer are difficult to guarantee, and the potential safety hazard of short circuit exists in the power supply process.

SUMMERY OF THE UTILITY MODEL

An object of the embodiments of the present invention is to provide a driving circuit and a switch module, which are used to ensure a creepage distance and an electrical gap between output power sources.

In a first aspect, an embodiment of the present invention provides a driving circuit, including: the half-bridge driving circuit comprises a half-bridge driving unit, a plurality of transformers and a rectifying and filtering unit corresponding to each transformer; wherein, the primary sides of a plurality of transformers are connected in parallel; the input end of the half-bridge driving unit is connected with an external power supply, and the external power supply is used for supplying power to the half-bridge driving unit; the output end of the half-bridge driving unit is connected with the primary sides of the plurality of transformers, and the half-bridge driving unit is used for controlling the input voltage of the primary side of each transformer; the secondary side of each transformer is connected with a corresponding rectifying and filtering unit, and the transformer is used for isolating the rectifying and filtering unit corresponding to the transformer from the rectifying and filtering units corresponding to other transformers; the rectification filter unit is also connected with the power electronic switch element and is used for providing direct current for the corresponding power electronic switch element.

According to the embodiment of the application, the voltage of the primary sides of the plurality of parallel transformers is controlled by the half-bridge driving unit, and then the voltages are rectified by the rectifying and filtering circuit connected with the secondary side of each transformer to obtain a plurality of groups of direct current outputs, so that the obtained plurality of direct current power supplies and the corresponding transformers can be distributed beside each power electronic switch element in a subsection mode, and proper creepage distance and electrical clearance are guaranteed between each power supply.

In an alternative embodiment, the half-bridge driving unit includes: the circuit comprises a voltage stabilizing circuit, a half-bridge controller and a half-bridge circuit; the voltage stabilizing circuit is respectively connected with the external power supply and the half-bridge controller and is used for supplying power to the half-bridge controller; the half-bridge controller is connected with the control end of the half-bridge circuit and is used for outputting a control signal to control the state of the half-bridge circuit; the input end of the half-bridge circuit is connected with the external power supply, the output end of the half-bridge circuit is connected with the primary side of the transformer, and the half-bridge circuit is used for controlling the input voltage of the primary side of the transformer according to the control signal.

According to the embodiment of the application, the half-bridge controller is arranged to control the state of the half-bridge circuit through the output control signal, so that the alternating current input to the primary side of the transformer is controlled through the change of the state of the half-bridge circuit, and the transmission of the power is ensured.

In an alternative embodiment, the control signal includes a first control signal and a second control signal, and the half-bridge circuit includes: the field effect transistor comprises a first insulated gate field effect transistor, a second insulated gate field effect transistor, a first capacitor and a second capacitor; the drain electrode of the first insulated gate field effect transistor and the first end of the first capacitor are both connected with the external power supply; the source electrode of the first insulated gate field effect transistor and the drain electrode of the second insulated gate field effect transistor are connected with the sixth pin of the half-bridge controller and the eighth pin of the half-bridge controller, and are also connected with the first input end of the transformer; the grid electrode of the first insulated gate field effect transistor is connected with a seventh pin of the half-bridge controller, and the seventh pin of the half-bridge controller is used for outputting a first control signal to control the state of the first insulated gate field effect transistor; the grid electrode of the second insulated gate field effect transistor is connected with a fourth pin of the half-bridge controller, and the fourth pin of the half-bridge controller is used for outputting a second control signal to control the state of the second insulated gate field effect transistor; the source electrode of the second insulated gate field effect transistor and the second end of the second capacitor are both grounded, and the first end of the second capacitor and the second end of the first capacitor are both connected with the second input end of the transformer.

According to the embodiment of the application, the voltage of the primary side of the transformer is controlled through the change of the on state and the off state of the two insulated gate field effect tubes, so that the alternating current is applied to the primary side of the transformer to transmit the electric power.

In an optional embodiment, a bootstrap capacitor is disposed between the eighth pin of the half-bridge controller and the sixth pin of the half-bridge controller, and the bootstrap capacitor is configured to raise a voltage of the eighth pin of the half-bridge controller, so as to set specific values of output voltages of the eighth pin and the sixth pin of the half-bridge controller.

In an optional embodiment, the voltage stabilizing circuit comprises a voltage stabilizer, a first diode, a third capacitor and a first resistor; the first pin of the voltage stabilizer is connected with one end of the third capacitor, and the other end of the third capacitor, the second pin of the voltage stabilizer, the third pin of the voltage stabilizer, the sixth pin of the voltage stabilizer and the seventh pin of the voltage stabilizer are all grounded; a first pin of the voltage stabilizer is connected with a fifth pin of the half-bridge controller; the first pin of the voltage stabilizer is also connected with the anode of the first diode, the cathode of the first diode is connected with one end of the first resistor, and the other end of the first resistor is connected with the eighth pin of the half-bridge controller; and an eighth pin of the voltage stabilizer is connected with the external power supply.

The embodiment of the application can ensure the stability of the power supply for driving the half-bridge controller by configuring the voltage-stabilizing tube, thereby ensuring the stable output of the half-bridge controller and preventing the condition that the device is damaged due to overlarge output fluctuation.

In an optional embodiment, the half-bridge driving unit further includes a frequency control circuit, the frequency control circuit is connected to the voltage stabilizing circuit and the half-bridge controller, respectively, and the frequency control circuit is configured to set a frequency of the output control signal of the half-bridge controller, so as to adjust a frequency of the voltage applied to the primary side of the transformer.

In an optional embodiment, the half-bridge driving unit further includes a filter circuit, the filter circuit includes a fourth capacitor and a fifth capacitor connected in parallel, one end of the fourth capacitor and one end of the fifth capacitor are both connected to the external power supply, and the other end of the fourth capacitor and the other end of the fifth capacitor are both grounded.

According to the embodiment of the application, the fourth capacitor and the fifth capacitor are arranged for filtering, so that the current applied to the primary side of the transformer is ensured to be smooth.

In an alternative embodiment, the rectifying and filtering unit includes: the second diode, the third diode, the sixth capacitor and the seventh capacitor; the anode of the second diode and the cathode of the third diode are both connected with the first output end of the transformer; the anode of the second diode is connected with the first end of the sixth capacitor, and the sixth capacitor is used for storing energy when the second diode is switched on and discharging energy when the second diode is switched off; the anode of the third diode is connected with the first end of the seventh capacitor, and the seventh capacitor is used for storing energy when the third diode is switched on and discharging energy when the third diode is switched off; a second end of the sixth capacitor and a second end of the seventh capacitor are both connected with a second output end of the transformer, wherein the sixth capacitor and the seventh capacitor are connected in parallel; and the first end of the sixth capacitor and the first end of the seventh capacitor are also connected with the power electronic switch element corresponding to the rectifying and filtering unit.

According to the embodiment of the application, the secondary side of the transformer is provided with the diode and the capacitor, and the function of converting alternating current into direct current is realized through the matching of the diode and the capacitor so as to serve as a power electronic switching element for driving and connecting a direct current power supply.

In an optional embodiment, the rectifying and filtering unit further includes: the second resistor, the third resistor, the fourth resistor, the eighth capacitor, the ninth capacitor and the voltage stabilizing diode; the second resistor, the third resistor, the fourth resistor and the eighth capacitor are connected in parallel, and one end of the second resistor is connected with the first end of the sixth capacitor; the other end of the second resistor is respectively connected with the anode of the voltage stabilizing diode and one end of the ninth capacitor; and the cathode of the voltage stabilizing diode and the other end of the ninth capacitor are both connected with the first end of the seventh capacitor.

According to the embodiment of the application, the plurality of resistors and the plurality of capacitors are arranged between the rectifying and filtering unit and the power electronic switch element, and the voltage value of the direct-current power supply output by the rectifying and filtering unit can be set by utilizing the parameter values of the plurality of resistors and the plurality of capacitors, so that the voltage output by the direct-current power supply is matched with the voltage required by the power electronic switch element.

In a second aspect, an embodiment of the present invention provides a switch module, including: the drive circuit and at least one power electronic switching element of any of the preceding embodiments; the input end of the driving circuit is connected with an external power supply, each output end of a plurality of output ends in the driving circuit is respectively connected with a corresponding power electronic switch element, and the driving circuit is used for driving the power electronic switch elements connected with the driving circuit.

This application embodiment drives a power electronic switch element respectively through a plurality of mutual isolation's that set up drive circuit output, can guarantee when the uniformity of a plurality of power electronic switch element work, also can guarantee to have suitable creepage distance and electric clearance between every output to ensure the stable work of switch module.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are required to be used in the embodiments of the present application will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and that those skilled in the art can also obtain other related drawings based on the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a driving circuit according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of a half-bridge driving unit according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a rectifying and filtering unit and a transformer according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a switch module according to an embodiment of the present disclosure.

Icon: 100-a drive unit; 200-a rectifying and filtering unit; 10-a drive circuit; 20-power electronic switching elements; 30-external power supply.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application.

Fig. 1 is a schematic structural diagram of a driving circuit according to an embodiment of the present application, where the driving circuit 10 includes: a half-bridge driving unit 100, a plurality of transformers, and a rectifying and filtering unit 200 corresponding to each transformer; wherein, the primary sides of a plurality of transformers are connected in parallel; the input end of the half-bridge driving unit 100 is connected to an external power supply 30, and the external power supply 30 is used for supplying power to the half-bridge driving unit 100; the output end of the half-bridge driving unit 100 is connected to the primary sides of the plurality of transformers, and the half-bridge driving unit 100 is configured to control the input voltage of the primary side of each transformer; the secondary side of each transformer is connected with the corresponding rectifying and filtering unit 200, and the transformer is used for isolating the rectifying and filtering unit 200 corresponding to the transformer from the rectifying and filtering units 200 corresponding to other transformers; the rectifying and filtering unit 200 is further connected to the power electronic switching element 20, and the rectifying and filtering unit 200 is configured to provide direct current to the corresponding power electronic switching element 20.

The half-bridge driving unit 100 drives the power tube to generate an ac trigger signal with a large current by using the dc power of the external power source 30, so as to apply the ac power with a large current to the transformer, and output the electric energy according to the requirement through the transformer and the rectifying and filtering unit 200. Compared with the traditional mode of direct drive through a single chip microcomputer, the half-bridge drive unit 100 has stronger driving capability and can output electric energy with larger power, so that more power electronic switching elements 20 can be driven. The external power supply 30 may be a 23V dc power supply, and the specific voltage of the external power supply 30 may be adjusted according to actual driving requirements.

Moreover, the transformer can isolate the rectifying and filtering unit 200 corresponding to itself from the rectifying and filtering units 200 corresponding to other transformers, for example, the transformer a corresponds to the rectifying and filtering unit B, and the transformer C corresponds to the rectifying and filtering unit D, so the transformer a can isolate the rectifying and filtering unit B from the rectifying and filtering unit D. Compared with the traditional mode that a transformer is arranged in the driving circuit 10, the secondary side of the same transformer outputs a plurality of power supplies, and because the output is the high-voltage power supply, the area of the transformer needs to be set to be large, so that the distance between the plurality of power supplies is set to be short when wiring is carried out, the creepage distance and the electric clearance are small, and the problem of power supply short circuit is easy to occur in the normal power supply process. And this application embodiment is through setting up a plurality of transformers, and the mode of a power of the secondary output of each transformer can be through setting up the transformer dispersion to the rectification filter unit 200 of guaranteeing to be connected with the secondary of transformer can follow the transformer that corresponds and set up, makes the distance between the different power of output set far away during the wiring, has safe creepage distance and electric clearance, can guarantee drive circuit 10's normal operating.

Meanwhile, compared with a mode that one transformer is arranged in a traditional driving power supply to control a plurality of output power supplies, the mode that one transformer is arranged to control one output power supply can have better current output characteristics and transient control characteristics, when the power utilization state of a load product connected with the output power supply is changed greatly, the power output can respond in time, and fluctuation and clutter in the output electric energy are prevented.

It can be noted that by connecting the primary sides of the plurality of transformers in parallel, the secondary outputs of the plurality of transformers can be ensured to be consistent, so that the operating states of the plurality of power electronic switching elements 20 that are driven can be kept consistent. The power electronic switch element 20 may be an Insulated Gate Bipolar Transistor (IGBT) or a Field Effect Transistor (MOSFET), and the specific type of the power electronic switch element 20 is not limited and may be selected according to actual driving requirements.

It should be further noted that the transformer may be a step-up transformer, a step-down transformer, or a transformer with a turn ratio of 1:1, that is, an isolation transformer with an electrically isolated input winding and output winding, so that the transformer can isolate the respective currents of the primary winding and the secondary winding while isolating the corresponding rectifying and filtering unit 200 from the corresponding rectifying and filtering units 200 of other transformers, thereby suppressing high-frequency noise from being transmitted to the secondary winding of the transformer. And moreover, the transformer with the turn ratio of 1:1 is adopted, so that the input voltage and the output voltage of the transformer can be equal, a feedback circuit is not required to be arranged, and the problem of controlling the output stability of the transformer according to a feedback signal acquired by a linear optical couple in the feedback circuit is solved. The specific type of the transformer is not limited, and can be selected according to actual driving requirements.

Next, the rectifying and smoothing unit 200 may convert the ac power of the secondary side of the transformer into dc power for output, so that the output dc power may drive the power electronic switching element 20 connected to the rectifying and smoothing unit 200. The number of transformers is the same as that of the rectifying and filtering units 200, and the specific number can be adjusted according to the number of power electronic switching elements 20 required to be driven. For example, when 6 power electronic switching elements 20 need to be driven, 6 transformers and 6 rectifying and filtering units 200 may be correspondingly arranged.

Fig. 2 is a schematic structural diagram of a half-bridge driving unit 100 according to an embodiment of the present application, where the half-bridge driving unit 100 includes: the circuit comprises a voltage stabilizing circuit, a half-bridge controller and a half-bridge circuit; the voltage stabilizing circuit is respectively connected with the external power supply 30 and the half-bridge controller, and is used for supplying power to the half-bridge controller; the half-bridge controller is connected with the control end of the half-bridge circuit and is used for outputting a control signal to control the state of the half-bridge circuit; the input end of the half-bridge circuit is connected with the external power supply 30, the output end of the half-bridge circuit is connected with the primary side of the transformer, and the half-bridge circuit is used for controlling the input voltage of the primary side of the transformer according to the control signal.

The voltage stabilizing circuit can process the external power supply 30, and the processed electric energy is used for driving the half-bridge controller, so that the working stability of the half-bridge controller is ensured. Furthermore, the half-bridge controller can control the state of the transistor in the half-bridge circuit by outputting the control signal, so that the state of the output end of the half-bridge circuit, namely the state of the input electric energy of the primary side of the transformer, can be correspondingly changed along with the change of the control signal received by the input end of the half-bridge circuit.

For example, the half-bridge circuit may control the voltage at the output terminal to change in both +11.5v or-11.5 v according to the received control signal, so as to control the change of the state of the input power at the primary side of the transformer. The forward direction and the reverse direction of the voltage output by the output end of the half-bridge circuit can be specified directions, and can also be set according to the direction of the voltage input by the external power supply 30, the direction and the voltage size of the voltage output by the specific output end are not limited, and the voltage can be adjusted according to actual driving requirements.

As an embodiment of the present application, the control signal includes a first control signal and a second control signal, and the half-bridge circuit includes: the first insulated gate field effect transistor Q1, the second insulated gate field effect transistor Q2, the first capacitor C1 and the second capacitor C2; the drain electrode of the first insulated gate field effect transistor Q1 and the first end of the first capacitor C1 are both connected with the external power supply 30; the source electrode of the first insulated gate field effect transistor Q1 and the drain electrode of the second insulated gate field effect transistor Q2 are both connected with the sixth pin of the half-bridge controller and the eighth pin of the half-bridge controller, and are also connected with the first input end of the transformer; the grid electrode of the first insulated gate field effect transistor Q1 is connected with the seventh pin of the half-bridge controller, and the seventh pin of the half-bridge controller is used for outputting a first control signal to control the state of the first insulated gate field effect transistor Q1; the gate of the second insulated gate field effect transistor Q2 is connected to the fourth pin of the half-bridge controller, and the fourth pin of the half-bridge controller is configured to output a second control signal to control the state of the second insulated gate field effect transistor Q2; the source of the second insulated gate field effect transistor Q2 and the second end of the second capacitor C2 are both grounded, and the first end of the second capacitor C2 and the second end of the first capacitor C1 are both connected to the second input terminal of the transformer.

The type of the first control signal and the second control signal output by the half-bridge controller can be level signals, and when the first controller signal is at a high level, the second control signal can be at a low level; when the first controller signal is at a low level, the second control signal may be at a high level; the first control signal and the second control signal may be low level signals at the same time. Moreover, the difference value of the high and low levels can be determined according to the difference value of the pinch-off voltage and the turn-on voltage of the grid electrode of the insulated gate field effect transistor.

And secondly, the on and off of the source electrode and the drain electrode of the insulated gate field effect transistor can be changed according to the grid voltage of the insulated gate field effect transistor, so that the voltage and the direction of the primary side of the transformer are changed.

For example, assuming that the voltage across the first capacitor C1 and the voltage across the second capacitor C2 are both +11.5V, when the first control signal is a high level signal and the second control signal is a low level signal, the first igbt Q1 is turned on, and the second igbt Q2 is turned off, and at this time, the voltage on the primary side of the transformer is the same as the voltage on the first capacitor C1, but in the opposite direction, the voltage on the primary side of the transformer is-11.5V. When the first control signal is a low level signal and the second control signal is a high level signal, the first insulated gate field effect transistor Q1 is turned off, the second insulated gate field effect transistor Q2 is turned on, and at this time, the voltage of the primary side of the transformer is the same as the voltage of the second capacitor C2 in the same direction, and the voltage of the primary side of the transformer is + 11.5V. When the first control signal is a low level signal and the second control signal is a low level signal, the first insulated gate field effect transistor Q1 is turned off, the second insulated gate field effect transistor Q2 is turned off, and the primary side of the transformer is in a short circuit state. The voltage of the primary input of the transformer is related to the sizes of the first capacitor C1 and the second capacitor C2, and the specific voltage of the primary input of the transformer is not limited to the sizes of the first capacitor C1 and the second capacitor C2, and can be adjusted according to actual driving requirements.

It can be noted that the half-bridge controller may be a vehicle gauge controller chip AUIR2085S, an eighth pin of the half-bridge controller is a high side floating supply voltage pin, and the eighth pin is used for receiving an input voltage. And a seventh pin of the half-bridge controller is a high-side floating output voltage pin, a fourth pin of the half-bridge controller is a low-side output voltage pin, and the seventh pin and the fourth pin are used for outputting control signals. The first pin and the third pin of the half-bridge controller are grounded, the fifth pin of the half-bridge controller is a low-side power supply voltage, and the fifth pin is also used for receiving an input voltage. And the second pin of the half-bridge controller is a frequency input pin. The specific type of the half-bridge controller is not limited, and can be adjusted according to actual driving requirements.

It should be further noted that the fourth pin of the transformer may be used as the first input end of the transformer, the third pin of the transformer may be used as the second input end of the transformer, and the specific correspondence between the pin and the input end may be adjusted according to actual driving requirements. The first input terminal of the transformer and the sixth pin of the half-bridge controller may be further provided with a filter inductor L1.

On the basis of the above embodiment, a fifth resistor R5 is arranged between the gate of the first insulated gate field effect transistor Q1 and the seventh pin of the half-bridge controller, a tenth capacitor C10 and a sixth resistor R6 are arranged between the gate of the first insulated gate field effect transistor Q1 and the sixth pin of the half-bridge controller, and the tenth capacitor C10 and the fifth resistor R5 are connected in parallel, so that the on-off of the first insulated gate field effect transistor Q1 is accelerated through the cooperation of the fifth resistor R5, the tenth capacitor C10 and the sixth resistor R6, the switching frequency is improved, the transistor loss is reduced, and the temperature rise of the transistor is not too high. Similarly, a seventh resistor R7, an eleventh capacitor C11 and an eighth resistor R8 may be disposed at the gate of the second igbt Q2, and will not be described herein.

On the basis of the above embodiment, a bootstrap capacitor C26 is disposed between the eighth pin of the half-bridge controller and the sixth pin of the half-bridge controller, and the bootstrap capacitor C26 is configured to raise a voltage of the eighth pin of the half-bridge controller, so that a supply voltage of the eighth pin is about twice an output voltage of an external power supply, thereby ensuring that the seventh pin and the fourth pin of the half-bridge controller can output a control signal with a good level, and realizing driving of the insulated gate field effect transistor. The specific size of the bootstrap capacitor C26 is not limited, and may be adjusted according to the size of the pin output voltage actually required.

As another embodiment of the present application, the voltage stabilizing circuit includes a voltage regulator U1, a first diode D1, a third capacitor C3, and a first resistor R1; a first pin of the voltage regulator U1 is connected to one end of the third capacitor C3, and the other end of the third capacitor C3, a second pin of the voltage regulator U1, a third pin of the voltage regulator U1, a sixth pin of the voltage regulator U1, and a seventh pin of the voltage regulator U1 are all grounded; a first pin of the voltage stabilizer U1 is connected with a fifth pin of the half-bridge controller; the first pin of the voltage stabilizer U1 is further connected with the anode of the first diode D1, the cathode of the first diode D1 is connected with one end of the first resistor R1, and the other end of the first resistor R1 is connected with the eighth pin of the half-bridge controller; the eighth pin of the regulator U1 is connected to the external power supply 30.

The voltage stabilizer U1 is a device capable of automatically adjusting output voltage, and is used to stabilize power supply voltage, which has large fluctuation and cannot meet the requirements of electrical equipment, within its set value range, so that various circuits or electrical equipment can normally operate under rated operating voltage. The voltage of the eighth pin of regulator U1 can be stably input to regulator U1 to the voltage after will stabilizing passes through the first pin of regulator U1 and the first half-bridge controller of inputing, so that the half-bridge controller steady operation, the condition of preventing to appear leading to half-bridge controller damage because of output fluctuation is too big.

Furthermore, the voltage regulator U1 may be an LM138K three-terminal adjustable 1.2V to 32V voltage regulator (5A), or an LM431ACZ precision adjustable 2.5V to 36V reference voltage regulator, and the specific type of the voltage regulator U1 is not limited, and may be adjusted according to actual requirements.

It should be noted that, in the embodiment of the present application, the first diode D1 is provided to limit the direction of the current output from the first pin of the regulator U1, and the values of the first resistor R1 and the third capacitor C3 are provided to adjust the stability of the voltage output from the first pin of the regulator. The specific values of the first resistor R1 and the third capacitor C3 are not limited, and may be set according to the voltage stabilizing effect required in practice.

As another embodiment of the present application, the half-bridge driving unit 100 further includes a frequency control circuit, the frequency control circuit is respectively connected to the voltage stabilizing circuit and the half-bridge controller, and the frequency control circuit is configured to set a frequency of the control signal output by the half-bridge controller, so as to adjust a frequency of the voltage applied to the primary side of the transformer.

On the basis of the above embodiment, the frequency control circuit includes a ninth resistor R9 and a twelfth capacitor C12; one end of the ninth resistor R9 is connected to the first pin of the voltage regulator U1 and the fifth pin of the half-bridge controller, respectively, the other end of the ninth resistor R9 and one end of the twelfth capacitor C12 are both connected to the second pin of the half-bridge controller, the other end of the twelfth capacitor C12 is grounded, and the two ends of the ninth resistor R9 and the twelfth capacitor C12 are also connected in parallel to the thirteenth capacitor C13.

The frequency of the control signal output by the half-bridge controller can be adjusted by setting parameters of the ninth resistor R9 and the twelfth capacitor C12, so as to control the switching frequency of the first igbt Q1 and the second igbt Q2 in the half-bridge circuit, the switching frequency can be generally adjusted in the interval of [70kHz,300kHz ], specific values of the switching frequency and specific parameters of the ninth resistor R9 and the twelfth capacitor C12 are not limited, and the switching frequency can be adjusted according to the actual circuit board space size of the driving circuit 10 and the volt-second product of the transformer. For example, the transformer may be a 44Vusec volt-second product transformer, and the formula for calculating the volt-second product according to the transformer is as follows: if ET is the volt-second product of the transformer, V is the voltage applied to the transformer, D is the duty ratio of the control signal, and f is the switching frequency, the switching frequency may be set to 120 kHz. The specific value of the volt-second product of the transformer is not limited and can be adjusted according to the actual driving requirement.

As another embodiment of the present application, the half-bridge driving unit 100 further includes a filter circuit, the filter circuit includes a fourth capacitor C4 and a fifth capacitor C5 connected in parallel, one end of the fourth capacitor C4 and one end of the fifth capacitor C5 are both connected to the external power supply 30, and the other end of the fourth capacitor C4 and the other end of the fifth capacitor C5 are both grounded.

Fig. 3 is a schematic structural diagram of a rectifying and filtering unit 200 and a transformer according to an embodiment of the present disclosure, where the rectifying and filtering unit 200 includes: a second diode D2, a third diode D3, a sixth capacitor C6, and a seventh capacitor C7; the anode of the second diode D2 and the cathode of the third diode D3 are both connected with the first output end of the transformer; the anode of the second diode D2 is connected to the first end of the sixth capacitor C6, and the sixth capacitor C6 is configured to store energy when the second diode D2 is turned on and discharge energy when the second diode D2 is turned off; the anode of the third diode D3 is connected to the first end of the seventh capacitor C7, and the seventh capacitor C7 is configured to store energy when the third diode D3 is turned on and discharge energy when the third diode D3 is turned off; a second terminal of the sixth capacitor C6 and a second terminal of the seventh capacitor C7 are both connected to the second output terminal of the transformer, wherein the sixth capacitor C6 and the seventh capacitor C7 are connected in parallel; the first end of the sixth capacitor C6 and the first end of the seventh capacitor C7 are also connected to the power electronic switch element 20 corresponding to the rectifying and filtering unit 200.

In the embodiment of the present application, the secondary side of the transformer is provided with the diode and the capacitor, and the function of converting ac into dc is realized by the cooperation of the diode and the capacitor, so as to serve as a dc power supply to drive the connected power electronic switching element 20.

For example, if the first igbt Q1 is turned on, the second igbt Q2 is turned off, and when the voltage of the primary side of the transformer is-11.5V, the second diode D2 is turned off, the third diode D3 is turned on, the sixth capacitor C6 is used for discharging energy, and the seventh capacitor C7 is used for storing energy; assuming that the first insulated gate field effect transistor Q1 is turned off, the second insulated gate field effect transistor Q2 is turned on, and when the voltage of the primary side of the transformer is +11.5V, the second diode D2 is turned on, the third diode D3 is turned off, the sixth capacitor C6 is used for storing energy, and the seventh capacitor C7 is used for discharging energy, so that commutation is realized by the two diodes and the energy storage capacitor. Thus, a voltage can be output through the first terminal of the sixth capacitor C6 and the first terminal of the seventh capacitor C7, and a dc power supply for driving the power electronic switching element 20 is obtained.

It should be noted that, if the first insulated-gate field-effect transistor Q1 is turned off and the second insulated-gate field-effect transistor Q2 is turned off, when the primary side of the transformer is in a short-circuit state, the second diode D2 is turned on, the third diode D3 is turned on, the sixth capacitor C6 is used for discharging energy, and the seventh capacitor C7 is used for discharging energy, the output of electric energy can also be realized.

It should be further noted that the seventh pin of the transformer may be connected to the fifth pin of the transformer, and both the seventh pin and the sixth pin may be connected to the eighth pin of the transformer, and both the sixth pin and the eighth pin may be used as the second output terminal. The corresponding relation between the specific pin of the transformer and the output end can be adjusted according to actual driving requirements.

On the basis of the above embodiment, the rectifying and filtering unit 200 further includes: a second resistor R2, a third resistor R3, a fourth resistor R4, an eighth capacitor C8, a ninth capacitor C9 and a zener diode D4; the second resistor R2, the third resistor R3, the fourth resistor R4 and the eighth capacitor C8 are connected in parallel, and one end of the second resistor R2 is connected with a first end of the sixth capacitor C6; the other end of the second resistor R2 is respectively connected with the anode of the zener diode D4 and one end of the ninth capacitor C9; the cathode of the zener diode D4 and the other end of the ninth capacitor C9 are both connected to the first end of the seventh capacitor C7.

In the embodiment of the present application, a plurality of resistors and capacitors are disposed between the rectifying and filtering unit 200 and the power electronic switching element 20, and the voltage value of the dc power supply output by the rectifying and filtering unit 200 can be set by using the parameter values of the plurality of resistors and capacitors, so as to ensure that the voltage output by the dc power supply is matched with the voltage required by the power electronic switching element 20. For example, it is set that a voltage of 17V is outputted through the first terminal of the sixth capacitor C6 and a voltage of-6V is outputted through the first terminal of the seventh capacitor C7. Meanwhile, the zener diode D4 may also ensure the stability of the output voltage of the rectifying and filtering unit 200. The specific parameters of the second resistor R2, the third resistor R3, the fourth resistor R4, the eighth capacitor C8 and the ninth capacitor C9 are not limited, and may be adjusted according to the actual driving requirements.

It should be further noted that the structures of the rectifying and filtering units 200 respectively connected to each transformer may be the same, and detailed descriptions of the structures of the rectifying and filtering units 200 connected to other transformers are omitted here.

Fig. 4 is a schematic structural diagram of a switch module according to an embodiment of the present application, and based on the same concept, the switch module includes the driving circuit 10 and at least one power electronic switching element 20 according to any of the above embodiments; the input end of the driving circuit 10 is connected to an external power source 30, each of the plurality of output ends of the driving circuit 10 is connected to a corresponding one of the power electronic switching elements 20, and the driving circuit 10 is configured to drive the power electronic switching element 20 connected to itself.

This application embodiment drives a power electronic switch element 20 respectively through setting up a plurality of mutual isolation's of drive circuit 10 output, can guarantee when the uniformity of a plurality of power electronic switch element 20 work, also can guarantee to have suitable creepage distance and electric clearance between every output to ensure the stable work of switch module.

For example, each of the plurality of output terminals in the driving circuit 10 may be connected to one IGBT, and all the output terminals in the driving circuit 10 may also be connected to one IGBT module, where each output terminal controls one IGBT junction in the IGBT module. The connection relationship between the specific driving circuit 10 and the power electronic switching element 20 can be adjusted according to the actual driving requirement.

In summary, the present application provides a driving circuit 10 and a switch module, wherein a half-bridge driving unit 100 is disposed in the driving circuit 10 to control the voltages of the primary sides of a plurality of parallel transformers, and then the voltages are rectified by a rectifying and filtering circuit connected to the secondary side of each transformer, so as to obtain a plurality of sets of dc outputs, and thus, the obtained plurality of dc power supplies can be distributed beside each power electronic switch element 20 together with the corresponding transformers, thereby ensuring that each power supply has a proper creepage distance and an electrical gap, and ensuring the stable operation of the switch module.

In the description of the present application, it should be noted that the terms "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships that the products of the application usually place when using, and are only used for convenience in describing the present application and simplifying the description, but do not indicate or imply that the devices or elements that are referred to must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

It should also be noted that, unless expressly stated or limited otherwise, the terms "disposed" and "connected" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

The above description is only an example of the present application and is not intended to limit the scope of the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A driver circuit, comprising:

the half-bridge driving circuit comprises a half-bridge driving unit, a plurality of transformers and a rectifying and filtering unit corresponding to each transformer; wherein, the primary sides of a plurality of transformers are connected in parallel;

the input end of the half-bridge driving unit is connected with an external power supply, and the external power supply is used for supplying power to the half-bridge driving unit;

the output end of the half-bridge driving unit is connected with the primary sides of the plurality of transformers, and the half-bridge driving unit is used for controlling the input voltage of the primary side of each transformer;

the secondary side of each transformer is connected with a corresponding rectifying and filtering unit, and the transformer is used for isolating the rectifying and filtering unit corresponding to the transformer from the rectifying and filtering units corresponding to other transformers;

the rectification filter unit is also connected with the power electronic switch element and is used for providing direct current for the corresponding power electronic switch element.

2. The drive circuit of claim 1, wherein the half-bridge drive unit comprises: the circuit comprises a voltage stabilizing circuit, a half-bridge controller and a half-bridge circuit;

the voltage stabilizing circuit is respectively connected with the external power supply and the half-bridge controller and is used for supplying power to the half-bridge controller;

the half-bridge controller is connected with the control end of the half-bridge circuit and is used for outputting a control signal to control the state of the half-bridge circuit;

the input end of the half-bridge circuit is connected with the external power supply, the output end of the half-bridge circuit is connected with the primary side of the transformer, and the half-bridge circuit is used for controlling the input voltage of the primary side of the transformer according to the control signal.

3. The driver circuit of claim 2, wherein the control signal comprises a first control signal and a second control signal, the half-bridge circuit comprising: the field effect transistor comprises a first insulated gate field effect transistor, a second insulated gate field effect transistor, a first capacitor and a second capacitor;

the drain electrode of the first insulated gate field effect transistor and the first end of the first capacitor are both connected with the external power supply;

the source electrode of the first insulated gate field effect transistor and the drain electrode of the second insulated gate field effect transistor are connected with the sixth pin of the half-bridge controller and the eighth pin of the half-bridge controller, and are also connected with the first input end of the transformer;

the grid electrode of the first insulated gate field effect transistor is connected with a seventh pin of the half-bridge controller, and the seventh pin of the half-bridge controller is used for outputting a first control signal to control the state of the first insulated gate field effect transistor;

the grid electrode of the second insulated gate field effect transistor is connected with a fourth pin of the half-bridge controller, and the fourth pin of the half-bridge controller is used for outputting a second control signal to control the state of the second insulated gate field effect transistor;

the source electrode of the second insulated gate field effect transistor and the second end of the second capacitor are both grounded, and the first end of the second capacitor and the second end of the first capacitor are both connected with the second input end of the transformer.

4. The driving circuit according to claim 3, wherein a bootstrap capacitor is disposed between the eighth pin of the half-bridge controller and the sixth pin of the half-bridge controller, and the bootstrap capacitor is configured to raise a voltage of the eighth pin of the half-bridge controller.

5. The driving circuit of claim 2, wherein the voltage regulator circuit comprises a voltage regulator, a first diode, a third capacitor, and a first resistor;

the first pin of the voltage stabilizer is connected with one end of the third capacitor, and the other end of the third capacitor, the second pin of the voltage stabilizer, the third pin of the voltage stabilizer, the sixth pin of the voltage stabilizer and the seventh pin of the voltage stabilizer are all grounded;

a first pin of the voltage stabilizer is connected with a fifth pin of the half-bridge controller; the first pin of the voltage stabilizer is also connected with the anode of the first diode, the cathode of the first diode is connected with one end of the first resistor, and the other end of the first resistor is connected with the eighth pin of the half-bridge controller;

and an eighth pin of the voltage stabilizer is connected with the external power supply.

6. The driving circuit of claim 2, wherein the half-bridge driving unit further comprises a frequency control circuit, the frequency control circuit is connected to the voltage stabilizing circuit and the half-bridge controller respectively, and the frequency control circuit is configured to set a frequency of the control signal output by the half-bridge controller.

7. The driving circuit according to claim 2, wherein the half-bridge driving unit further comprises a filter circuit, the filter circuit comprises a fourth capacitor and a fifth capacitor connected in parallel, one end of the fourth capacitor and one end of the fifth capacitor are both connected to the external power supply, and the other end of the fourth capacitor and the other end of the fifth capacitor are both grounded.

8. The drive circuit according to any one of claims 1 to 7, wherein the rectifying and filtering unit includes: the second diode, the third diode, the sixth capacitor and the seventh capacitor;

the anode of the second diode and the cathode of the third diode are both connected with the first output end of the transformer;

the anode of the second diode is connected with the first end of the sixth capacitor, and the sixth capacitor is used for storing energy when the second diode is switched on and discharging energy when the second diode is switched off;

the anode of the third diode is connected with the first end of the seventh capacitor, and the seventh capacitor is used for storing energy when the third diode is switched on and discharging energy when the third diode is switched off;

a second end of the sixth capacitor and a second end of the seventh capacitor are both connected with a second output end of the transformer, wherein the sixth capacitor and the seventh capacitor are connected in parallel;

and the first end of the sixth capacitor and the first end of the seventh capacitor are also connected with the power electronic switch element corresponding to the rectifying and filtering unit.

9. The driving circuit according to claim 8, wherein the rectifying and filtering unit further comprises: the second resistor, the third resistor, the fourth resistor, the eighth capacitor, the ninth capacitor and the voltage stabilizing diode;

the second resistor, the third resistor, the fourth resistor and the eighth capacitor are connected in parallel, and one end of the second resistor is connected with the first end of the sixth capacitor;

the other end of the second resistor is respectively connected with the anode of the voltage stabilizing diode and one end of the ninth capacitor; and the cathode of the voltage stabilizing diode and the other end of the ninth capacitor are both connected with the first end of the seventh capacitor.

10. A switch module, comprising: a drive circuit according to any of the preceding claims 1-9 and at least one power electronic switching element;

the input end of the driving circuit is connected with an external power supply, each output end of a plurality of output ends in the driving circuit is respectively connected with a corresponding power electronic switch element, and the driving circuit is used for driving the power electronic switch elements connected with the driving circuit.