CN218301262U

CN218301262U - Motor drive module and motor control system

Info

Publication number: CN218301262U
Application number: CN202222400943.6U
Authority: CN
Inventors: 茅爱峰; 麻飞; 黄树
Original assignee: Kunshan No1 Precision Industry Technology Co ltd
Current assignee: Kunshan No1 Precision Industry Technology Co ltd
Priority date: 2022-09-09
Filing date: 2022-09-09
Publication date: 2023-01-13
Anticipated expiration: 2032-09-09

Abstract

The utility model discloses a motor drive module and motor control system, including first bridge arm circuit, second bridge arm circuit and third bridge arm circuit, the output of first bridge arm circuit, second bridge arm circuit and third bridge arm circuit is connected with outside motor respectively, the same bootstrap power and the earthing terminal of being connected of first bridge arm circuit, second bridge arm circuit and third bridge arm circuit, first bridge arm circuit, second bridge arm circuit and third bridge arm circuit all include bridge bootstrap circuit and bridge circuit down, bridge bootstrap circuit includes gate driver, bootstrap capacitor C1, bootstrap resistor R1, bootstrap diode D1, field effect transistor Q1, resistance R4, resistance R6, resistance R7, electric capacity C3 and zener diode D3, and this structure is through the redesign of bootstrap circuit structure for bootstrap capacitor can not the over-voltage condition, simultaneously, through the different three-phase bridge circuit of a bootstrap drive circuit drive to guarantee to have best synchronization performance between each axle.

Description

Motor drive module and motor control system

Technical Field

The utility model relates to a motor control field, in particular to motor drive module and motor control system.

Background

The bootstrap circuit is useful in the field of motor driving, and currently, when a three-phase motor is driven, a three-phase bridge circuit is mostly adopted, each phase circuit of the three-phase bridge circuit includes an upper bridge arm circuit and a lower bridge arm circuit, and the upper bridge arm mostly uses the bootstrap circuit.

As shown in fig. 7, the present bootstrap circuit includes a gate driver, a bootstrap capacitor CBOOT, a bootstrap resistor RBOOT, a bootstrap diode DBOOT, a field effect transistor Q1, an inductor Lout, a diode D1, a capacitor Cout, and a capacitor Cdrv;

the grid driver HO pin is connected with the G end of a field effect transistor Q1, the D end of the field effect transistor is used for connecting an external power supply VDC, the S end of the field effect transistor Q1 is connected with the VS pin of the grid driver, a bootstrap resistor RBOOT, a bootstrap diode DBOOT and a bootstrap capacitor CBOOT are sequentially connected in series, one end, far away from the bootstrap diode DBOOT, of the bootstrap resistor RBOOT is used for being connected with an external power supply VCC, two ends of the bootstrap capacitor CBOOT are respectively connected with the VB pin and the VS pin of the grid driver, one end of an inductor Lout is connected with the S end of the field effect transistor Q1, the other end of an inductor Lout is connected with one end of a capacitor Cout, the other end of the capacitor Cout is grounded, a capacitor Cdrv is connected between the VCC end and the GND end of the field effect transistor Q1, the VCC end of the field effect transistor Q1 is connected with the external GND, one end of the diode Cout is connected with the capacitor Cout, and the other end of the diode D1 is connected with the bootstrap diode CHOOT, so that current can only flow from the inductor Lout 1 to the bootstrap diode DSOOT, and the bootstrap diode CBOOT is connected with one end of the bootstrap diode CHOOT;

the VCC of the circuit is driven by a zero ohm power supply, connected to VB through an ideal diode. When a large current flows through the freewheeling diode, the VS voltage will be lower than ground due to the large di/dt. At this time, a latch-up hazard occurs because the parasitic diode DBS inside the gate driver is finally turned on in the VS to VB direction, causing the undershoot voltage to be superimposed with VDD, so that the bootstrap capacitor is overcharged.

SUMMERY OF THE UTILITY MODEL

The utility model provides a technical problem provide a motor drive module, it can solve the problem that bootstrap electric capacity was overcharged.

The utility model provides a technical scheme that its technical problem adopted is: a motor driving module comprises a first bridge arm circuit, a second bridge arm circuit and a third bridge arm circuit, wherein the output ends of the first bridge arm circuit, the second bridge arm circuit and the third bridge arm circuit are respectively connected with three-phase connecting ends of an external motor, and the first bridge arm circuit, the second bridge arm circuit and the third bridge arm circuit are connected with a same bootstrap power supply and a grounding end;

the first bridge arm circuit, the second bridge arm circuit and the third bridge arm circuit respectively comprise an upper bridge bootstrap circuit and a lower bridge circuit, wherein the upper bridge bootstrap circuit comprises a gate driver, a bootstrap capacitor C1, a bootstrap resistor R1, a bootstrap diode D1, a field effect transistor Q1, a resistor R4, a resistor R6, a resistor R7, a capacitor C3 and a Zener diode D3;

bootstrap resistance R1 ' S one end and bootstrap diode D1 input are established ties, the VCC end of gate driver is connected with bootstrap diode D1 ' S output, external power source VDD is connected to bootstrap resistance R1 ' S the other end, bootstrap capacitance C1 one end is connected with bootstrap diode D1 ' S output, the bootstrap capacitance C1 other end is connected with zener diode D3 ' S output, zener diode D3 ' S input ground connection, the VO end of gate driver is connected through resistance R4 and field effect transistor Q1 ' S G end, the GND end of gate driver is connected to the bootstrap capacitance C1 other end, the bootstrap capacitance C1 other end is connected with resistance R7 ' S one end, capacitance C3 ' S both ends are connected with resistance R4 and resistance R7 respectively, resistance R6 ' S both ends are connected with resistance R4 and resistance R7 respectively, field effect transistor Q1 ' S D end is connected with outside bootstrap voltage VDC, field effect transistor Q1 ' S S end is connected with resistance R7 ' S the other end.

Further, the method comprises the following steps: still include resistance R2 and diode D2, the one end of resistance R2 is connected with diode D2's output, the other end of resistance R2 is connected with resistance R4's one end, diode D2's input and field effect transistor Q1's G end are connected.

Further, the method comprises the following steps: the model of the gate driver is AN-6076.

Further, the method comprises the following steps: the bridge circuit further comprises an output current sampling circuit, and the input end of the output current sampling circuit is in signal connection with the output ends of the first bridge arm circuit, the second bridge arm circuit and the third bridge arm circuit.

Further, the method comprises the following steps: the bus voltage sampling circuit is characterized by further comprising a bus voltage sampling circuit, wherein the input end of the bus voltage sampling circuit is connected to the D1 end of the field effect tube.

Further, the method comprises the following steps: and bus overcurrent protection circuits are arranged between the first bridge arm circuit, the second bridge arm circuit and the third bridge arm circuit and the grounding end.

The utility model also discloses a motor control system, including the aforesaid motor drive module, including control module, buffer circuit, isolation opto-coupler, power module, bootstrap drive circuit and a plurality of three-phase bridge circuit, control module, buffer circuit, isolation opto-coupler module and bootstrap drive circuit connect gradually, power module is used for the bootstrap drive circuit power supply, bootstrap drive circuit and a plurality of three-phase bridge circuit are connected.

The beneficial effects of the utility model are that:

1. through the redesign of the bootstrap circuit structure, the bootstrap capacitor can not generate an overvoltage condition.

2. Different three-phase bridge circuits are driven by one bootstrap driving circuit, so that the best synchronization performance among the shafts is ensured.

Drawings

Fig. 1 is a schematic diagram of a three-phase bridge circuit.

Fig. 2 is a circuit diagram of a first bridge arm according to an embodiment of the present application.

Fig. 3 is a block diagram of a motor control system according to an embodiment of the present application.

Fig. 4 is a schematic diagram of the upper bridge bootstrap circuit in the embodiment of the present application during charging.

Fig. 5 is a schematic diagram of the upper bridge bootstrap circuit in the embodiment of the present application when discharging.

Fig. 6 is a schematic diagram of the upper bridge bootstrap circuit fet according to the embodiment of the present application when turned off.

Fig. 7 is a schematic diagram of a bootstrap circuit in the prior art.

Detailed Description

In order to make the above objects, features and advantages of the present invention more comprehensible, embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, as those skilled in the art will be able to make similar modifications without departing from the spirit and scope of the present invention.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

As shown in fig. 1, an embodiment of the present application discloses a motor driving module, which includes a first bridge arm circuit, a second bridge arm circuit, and a third bridge arm circuit, where output ends of the first bridge arm circuit, the second bridge arm circuit, and the third bridge arm circuit are respectively connected to a three-phase connection end of an external motor, and the first bridge arm circuit, the second bridge arm circuit, and the third bridge arm circuit are connected to a same bootstrap power supply and a ground end;

Specifically, as shown in fig. 2, the lower bridge circuit is a conventional circuit, and the lower bridge circuit independently supplies power, which is not improved in this application, and therefore details are not repeated here, and signal control terminals of gate drivers in the upper bridge bootstrap circuit and the lower bridge circuit are respectively connected to an external control signal. The field effect transistors Q1 and Q2 are driven to be switched on and off through the control signal, and the output voltage of the upper bridge bootstrap circuit or the output voltage of the lower bridge circuit is achieved.

Specifically, the grid driver further comprises a resistor R2 and a diode D2, one end of the resistor R2 is connected with the output end of the diode D2, the other end of the resistor R2 is connected with one end of a resistor R4, the input end of the diode D2 is connected with the G end of the field effect transistor Q1, and the grid driver is AN-6076 in model.

Specifically, when the motor is controlled to rotate, the upper and lower tubes of different phases are switched on two phases of the motor at each moment, and the upper and lower bridge arms of the same phase cannot be switched on simultaneously, so that a magnetic field is formed to enable the motor to rotate in one direction;

specifically, the upper bridge bootstrap voltage principle is as follows: the circuit principle is as shown in fig. 4, a control signal is externally given to the gate controller, so that the power supply VDD charges the bootstrap capacitor C1 through the bootstrap resistor R1 and the bootstrap diode D1, and since the bootstrap diode D1 and the zener diode D3 are respectively arranged at two ends of the bootstrap diode and the directions of the two diodes are opposite, the bootstrap capacitor C1 is ensured not to have an overvoltage condition. During the bootstrap voltage discharging process, as shown in fig. 5, the bootstrap capacitor C1 discharges, voltage is output to UA, and at the same time, the gate controller receives an external signal, and outputs a G end of the high-level field-effect transistor Q1, so that the D end and the S end of the field-effect transistor Q1 are turned on, so that the external bootstrap voltage VDC can flow to UA through the field-effect transistor, so that the voltage at UA is the sum of the bootstrap voltage VDC and the discharge voltage of the bootstrap capacitor C1, and bootstrap operation is implemented, when it is necessary to implement the field-effect transistor turn-off and return to the bootstrap capacitor C1 for charging operation, as shown in fig. 6, the field-effect transistor Q1 is implemented through the resistor R2 and the resistor R4, so as to implement the turn-off of the field-effect transistor Q1, because the diode D2 and the resistor R2 are added in the circuit, the transistor turn-off resistance can be reduced through the parallel connection of the resistor R2 and the resistor R4, and thus faster turn-off is implemented.

In this embodiment, the bridge further includes an output current sampling circuit, an input end of the output current sampling circuit is in signal connection with output ends of the first bridge arm circuit, the second bridge arm circuit and the third bridge arm circuit, and a bus voltage sampling circuit, an input end of the bus voltage sampling circuit is connected to the D1 end of the field effect transistor.

The output current sampling circuit and the bus voltage sampling circuit are both existing circuits, and in the technical scheme, the output current sampling circuit and the bus voltage sampling circuit are not improved.

The arrangement of the circuit structure enables the first bridge arm circuit, the second bridge arm circuit and the third bridge arm circuit to use the same set of bus voltage sampling circuit, and each module uses an independent bus overcurrent protection circuit.

The utility model also discloses a motor control system, including control module, buffer circuit, isolation opto-coupler, power module, bootstrapping drive circuit and a plurality of three-phase bridge circuit, control module, buffer circuit, isolation opto-coupler module and bootstrapping drive circuit connect gradually, power module is used for the power supply of bootstrapping drive circuit, bootstrapping drive circuit and a plurality of three-phase bridge circuit are connected.

It should be explained that the bootstrap driving circuit is a circuit module for driving the fet, and the three-phase bridge circuit is a circuit for connecting 6 fets with the motor.

In the circuit structure, different three-phase bridge circuits are driven by one bootstrap driving circuit, so that the best synchronization performance among all the shafts is ensured.

The above-mentioned embodiments, further detailed description of the objects, technical solutions and advantages of the present invention, it should be understood that the above-mentioned embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A motor drive module characterized by: the three-phase motor starting circuit comprises a first bridge arm circuit, a second bridge arm circuit and a third bridge arm circuit, wherein the output ends of the first bridge arm circuit, the second bridge arm circuit and the third bridge arm circuit are respectively connected with three-phase connecting ends of an external motor, and the first bridge arm circuit, the second bridge arm circuit and the third bridge arm circuit are connected with the same bootstrap power supply and a grounding end;

bootstrap resistor R1 'S one end and bootstrap diode D1 input are established ties, gate driver' S VCC end is connected with bootstrap diode D1 'S output, external power VDD is connected to bootstrap resistor R1' S the other end, bootstrap capacitor C1 one end is connected with bootstrap diode D1 'S output, the bootstrap capacitor C1 other end is connected with zener diode D3' S output, zener diode D3 'S input ground connection, gate driver' S VO end is connected with field effect transistor Q1 'S G end through resistance R4, gate driver' S GND end is connected to the bootstrap capacitor C1 other end, the bootstrap capacitor C1 other end is connected with resistance R7 'S one end, capacitance C3' S both ends are connected with resistance R4 and resistance R7 respectively, resistance R6 'S both ends are connected with resistance R4 and resistance R7 respectively, field effect transistor Q1' S D end is connected with outside bootstrap voltage VDC, field effect transistor Q1 'S S end is connected with resistance R7' S the other end.

2. The motor drive module of claim 1, wherein: still include resistance R2 and diode D2, the one end of resistance R2 is connected with diode D2's output, the other end of resistance R2 is connected with resistance R4's one end, diode D2's input and field effect transistor Q1's G end are connected.

3. The motor drive module of claim 1, wherein: the model of the gate driver is AN-6076.

4. The motor drive module of claim 1, wherein: the bridge circuit further comprises an output current sampling circuit, and the input end of the output current sampling circuit is in signal connection with the output ends of the first bridge arm circuit, the second bridge arm circuit and the third bridge arm circuit.

5. The motor drive module of claim 1, wherein: the bus voltage sampling circuit is characterized by further comprising a bus voltage sampling circuit, wherein the input end of the bus voltage sampling circuit is connected to the D1 end of the field effect tube.

6. The motor drive module of claim 1, wherein: and bus overcurrent protection circuits are arranged between the first bridge arm circuit, the second bridge arm circuit and the third bridge arm circuit and the grounding end.

7. A motor control system comprising a motor drive module according to any one of claims 1 to 6, characterized in that: including control module, buffer circuit, isolation opto-coupler, power module, bootstrapping drive circuit and a plurality of three-phase bridge circuit, control module, buffer circuit, isolation opto-coupler module and bootstrapping drive circuit connect gradually, power module is used for bootstrapping drive circuit power supply, bootstrapping drive circuit and a plurality of three-phase bridge circuit connection.