WO2021012866A1

WO2021012866A1 - Motor overvoltage protection circuit, undervoltage protection circuit, voltage protection circuit and motor

Info

Publication number: WO2021012866A1
Application number: PCT/CN2020/098023
Authority: WO
Inventors: 全威; 张晓菲; 敖文彬; 王颜章; 李宁
Original assignee: 珠海格力电器股份有限公司
Priority date: 2019-07-25
Filing date: 2020-06-24
Publication date: 2021-01-28
Also published as: CN110416973A

Abstract

A motor overvoltage protection circuit, an undervoltage protection circuit, a voltage protection circuit and a motor, wherein the motor overvoltage protection circuit comprises: a first controllable switch, a control terminal of the first controllable switch receiving a bus voltage collection signal of a motor, and a first terminal being grounded; and a second controllable switch, a control terminal of the second controllable switch being connected to a second terminal of the first controllable switch, a first terminal being grounded, and a second terminal being connected to a fault detection terminal of a driving chip of the motor. The overvoltage protection of the motor is achieved by means of the described circuit. The described motor overvoltage protection circuit has the characteristics of a simple circuit structure, low costs, and a wide application range. Overvoltage protection is achieved by means of using the inherent protection function of the driving chip, which will not occupy existing working circuit ports, thereby reducing the demands of the overvoltage protection function on chip resources without simultaneously affecting the existing protection function of the circuit.

Description

Motor overvoltage protection circuit, undervoltage protection circuit, voltage protection circuit and motor

Related application

This application claims the priority of the Chinese patent application filed on July 25, 2019, with the application number 201910680453.6, entitled "Motor overvoltage protection circuit, undervoltage protection circuit, voltage protection circuit and motor", the full text of which is hereby Introduced as a reference.

Technical field

This application relates to the technical field of protection circuits, in particular to motor overvoltage protection circuits, undervoltage protection circuits, voltage protection circuits and motors.

Background technique

At present, brushless DC motors are more and more widely used in various industries, such as air conditioners and air purifiers. This puts forward higher requirements on the performance, reliability and cost of the DC brushless motor. Protection functions such as over-current protection, current-limiting protection, stall protection, over-temperature protection, over-voltage protection and under-voltage protection have become important indicators to measure the reliability of brushless DC motors. Among them, the overvoltage protection and undervoltage protection of the DC bus voltage belong to a kind of motor protection. When the DC bus voltage exceeds the voltage range that the components can withstand, it is easy to damage the components and cause the motor to fail to operate. When the working voltage of the motor exceeds the design requirement voltage, the protection action of the motor is triggered, which is called overvoltage Protection; when the DC bus voltage is far lower than the normal working bus voltage of the components, the motor will have repeated speed adjustment fluctuations, and the running sound will fluctuate. If the motor runs in a low voltage environment for a long time, it will cause the efficiency of the power device to decrease. The working temperature exceeds the design temperature, causing damage to the components. When the working voltage of the motor is seriously lower than the design requirement voltage, the protection action of the motor is triggered. This is called undervoltage protection.

For the existing brushless DC motors with built-in controllers, the functions of motor over-voltage protection and under-voltage protection are all realized by the controller circuit; for the main control chip is a single-chip microcomputer, DSP or other programmable chips, the overvoltage And the undervoltage protection function is usually by sampling the bus voltage, and then sending the sampled signal to the drive chip U1, using chip programming to realize the protection mechanism; however, for the non-programmable DC brushless motor drive main control chip (such as DC brushless Motor-specific chip), which cannot be programmed by software to achieve overvoltage and undervoltage protection of the DC bus.

Summary of the invention

In view of this, the embodiments of the present application provide a motor overvoltage protection circuit, an undervoltage protection circuit, a voltage protection circuit, and a motor to overcome the lack of the prior art for using non-programmable DC brushless motor drive master control chips. The problem of motor protection against DC bus voltage.

According to the first aspect, an embodiment of the present application provides a motor overvoltage protection circuit, including: a first controllable switch, the control terminal of the first controllable switch receives a bus voltage collection signal of the motor, and the first terminal is grounded, The second end is connected to the high level; the second controllable switch, the control end of the second controllable switch is connected to the second end of the first controllable switch, the first end is grounded, and the second end is connected to the The fault detection terminal of the drive chip of the motor is connected to the high level.

Optionally, the motor overvoltage protection circuit further includes: a first resistor, a second resistor, and a first capacitor, wherein one end of the first resistor receives the bus voltage collection signal, and the other end is connected to the first resistor respectively. The control end of a controllable switch, one end of the first capacitor and one end of the second resistor are connected, and the other end of the second resistor and the other end of the first capacitor are grounded.

Optionally, the motor overvoltage protection circuit further includes: a first DC power source, a third resistor, and a fourth resistor, wherein the DC power source is connected to one end of the third resistor, and the third resistor is The other end is respectively connected to the second end of the first controllable switch and one end of the fourth resistor, and the other end of the fourth resistor is connected to the control end of the second controllable switch.

Optionally, the motor overvoltage protection circuit further includes: a second DC power source, a fifth resistor, and a second capacitor, wherein the second DC power source is connected to the second controllable switch through the fifth resistor. The second end is connected, one end of the second capacitor is connected to the first channel of the second controllable switch, and the other end is grounded.

According to a second aspect, an embodiment of the present application further provides a motor undervoltage protection circuit, including: a third controllable switch, the control terminal of the third controllable switch receives the bus voltage collection signal of the motor, and the first terminals are respectively It is connected with the fault detection terminal and the high level of the driving chip of the motor, and the second terminal is grounded.

Optionally, the motor undervoltage protection circuit further includes: a sixth resistor, a seventh resistor, and a third capacitor, wherein one end of the sixth resistor receives the bus voltage collection signal, and the other end is connected to the first Three controllable switches, one end of the third capacitor and one end of the seventh resistor are connected, and the other end of the seventh resistor is grounded to the other end of the third capacitor.

Optionally, the motor undervoltage protection circuit further includes: a third direct current power supply and an eighth resistor, wherein the third direct current power supply is connected to the first end of the third controllable switch through the eighth resistor .

According to a third aspect, an embodiment of the present application also provides a motor voltage protection circuit, including: the motor overvoltage protection circuit described in the first aspect and the motor undervoltage protection circuit described in the second aspect.

Optionally, the motor voltage protection circuit further includes: a signal acquisition circuit that includes a plurality of series-connected resistors, a ninth resistor, a tenth resistor, and a fourth capacitor, wherein the bus voltage of the motor is The multiple resistors connected in series are respectively connected to one end of the ninth resistor and one end of the tenth resistor, and the other end of the tenth resistor is respectively connected to one end of the fourth capacitor, the first end The control terminal of the controllable switch is connected to the control terminal of the third controllable switch, and the other end of the ninth resistor is connected to the other end of the fourth capacitor and then grounded.

Optionally, the motor voltage protection circuit further includes a comparator, the input terminals of which are respectively connected to the second terminal of the second controllable switch and the first terminal of the third controllable switch, The output terminal of the comparator is connected with the fault detection terminal of the driving chip of the motor.

According to a fourth aspect, an embodiment of the present application further provides a motor, the motor including the motor voltage protection circuit described in the third aspect.

The technical solution of this application has the following advantages:

1. In the motor overvoltage protection circuit provided by the embodiment of the application, when the bus voltage value of the motor exceeds the high voltage protection threshold of the motor itself, the control terminal of the first controllable switch receives the bus voltage collection signal of the motor to trigger the first controllable switch Turned on, after the first controllable switch is turned on, the control terminal of the second controllable switch is grounded, the second controllable switch is not turned on, and the second terminal of the second controllable switch outputs a high level to the failure of the drive chip of the motor At the detection end, the drive chip triggers fault protection and stops outputting drive signals to the motor. The motor stops, thereby realizing the overvoltage protection of the motor. The motor overvoltage protection circuit provided by the embodiment of the present application has the characteristics of simple circuit structure, low cost, and wide application range. , By using the inherent protection function of the driver chip to realize over-voltage protection, it will not occupy the existing working circuit port, reducing the requirement of the over-voltage protection function on chip resources, and at the same time not affecting the existing protection function of the circuit.

2. In the motor undervoltage protection circuit provided by the embodiment of the application, when the bus voltage value of the motor exceeds the motor's own low voltage protection threshold, the control terminal of the third controllable switch receives the motor's bus voltage collection signal less than the third controllable switch The third controllable switch does not conduct, the second controllable switch does not conduct, the first terminal of the third controllable switch outputs a high level to the fault detection terminal of the drive chip of the motor, and the drive chip triggers the fault Protection, stop outputting the drive signal to the motor. The motor stops, so as to realize the under-voltage protection of the motor. The motor under-voltage protection circuit provided by the embodiment of the present application has the characteristics of simple circuit structure, low cost, and wide application range. The protection function realizes under-voltage protection, and does not occupy the existing working circuit port, reduces the requirement of the under-voltage protection function on chip resources, and does not affect the existing protection function of the circuit.

3. The motor voltage protection circuit provided by the embodiments of this application realizes the overvoltage protection and undervoltage protection of the motor. The motor voltage protection circuit provided by the embodiments of this application has the characteristics of simple circuit structure, low cost, and wide application range. Utilize the inherent protection function of the driver chip to realize over-voltage protection and under-voltage protection, which will not occupy the existing working circuit ports, reduce the requirement of over-voltage protection function and under-voltage protection function on chip resources, and will not affect the circuit. Some protection functions.

4. The motor provided by the embodiment of the application realizes the overvoltage protection and undervoltage protection of the motor. The voltage protection circuit in the motor provided by the embodiment of the application has the characteristics of simple circuit structure, low cost, and wide application range. By using the inherent protection function of the driver chip to achieve over-voltage protection and under-voltage protection, it will not occupy the existing working circuit ports, which reduces the requirements of the over-voltage protection function and the under-voltage protection function on chip resources without affecting the circuit. Existing protection functions.

Description of the drawings

In order to more clearly illustrate the specific embodiments of this application or the technical solutions in the prior art, the following will briefly introduce the drawings that need to be used in the specific embodiments or the description of the prior art. Obviously, the appendix in the following description The drawings are some embodiments of the application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

FIG. 1 is a schematic structural diagram of a motor overvoltage protection circuit according to an embodiment of the application;

FIG. 2 is a schematic structural diagram of a motor undervoltage protection circuit according to an embodiment of the application;

Fig. 3 is a schematic structural diagram of a motor voltage protection circuit according to an embodiment of the application.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments It is a part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative work are within the protection scope of this application.

The technical features involved in the different implementations of the application described below can be combined with each other as long as they do not conflict with each other.

Figure 1 shows a schematic structural diagram of a motor overvoltage protection circuit provided by an embodiment of the present application. As shown in Figure 1, the motor overvoltage protection circuit includes: a first controllable switch Q1, and a control terminal of the first controllable switch Q1 Receive the bus voltage acquisition signal VBUS of the motor, the first end is grounded, and the second end is connected to high level; the second controllable switch Q2, the control end of the second controllable switch Q2 is connected to the second end of the first controllable switch Q1 , The first terminal is grounded, and the second terminal is respectively connected to the fault detection terminal F/S and high level of the drive chip U1 of the motor. In practical applications, the aforementioned high level is provided by the first DC power supply and the second DC power supply respectively. It should be noted that the motors involved in the embodiments of the present application are all brushless DC motors, and the built-in drive chip U1 of the brushless DC motor is an unprogrammable drive chip U1.

Specifically, in an embodiment, as shown in FIG. 1, the above-mentioned motor overvoltage protection circuit further includes: a first resistor R1, a second resistor R2, and a first capacitor C1, wherein one end of the first resistor R1 receives the bus The other end of the voltage acquisition signal VBUS is connected to the control end of the first controllable switch Q1, one end of the first capacitor C1 and one end of the second resistor R2, and the other end of the second resistor R2 and the other end of the first capacitor C1 are grounded . In practical applications, by reasonably setting the resistance of the first resistor R1 and the second resistor R2, the divided bus voltage collection signal VBUS is greater than the conduction voltage Vbe of the first controllable switch Q1, so that it has and only The first controllable switch Q1 can be turned on when the overvoltage protection threshold is triggered (for example, the overvoltage protection threshold of the bus voltage of the brushless DC motor is set to 400V). When the normal operating voltage (such as 310V), the first controllable The switch Q1 cannot be turned on. When the voltage is lower than the undervoltage protection threshold value (for example, the undervoltage protection threshold of the bus voltage of the brushless DC motor is set to 200V), the first controllable switch Q1 cannot be turned on.

Specifically, in an embodiment, as shown in FIG. 1, the above-mentioned motor overvoltage protection circuit further includes: a first DC power source, a third resistor R3, and a fourth resistor R4, wherein the DC power source and the third resistor R3 One end of the third resistor R3 is connected to the second end of the first controllable switch Q1 and one end of the fourth resistor R4, and the other end of the fourth resistor R4 is connected to the control end of the second controllable switch Q2 . In practical applications, the first DC power supply is a 5V power supply. When the first controllable switch Q1 is not turned on, the first DC power supply becomes the second controllable switch Q2 through the third resistor R3 and the fourth resistor R4. Power is supplied so that the second controllable switch Q2 is turned on.

Specifically, in an embodiment, as shown in FIG. 1, the above-mentioned motor overvoltage protection circuit further includes: a second DC power source, a fifth resistor R5, and a second capacitor C2, wherein the second DC power source passes through the fifth resistor R5 is connected to the second end of the second controllable switch Q2, one end of the second capacitor C2 is connected to the first channel of the second controllable switch Q2, and the other end is grounded. In practical applications, the above-mentioned first capacitor C1 and second capacitor C2 function as filtering. In practical applications, the second DC power supply is a 5V power supply. When the second controllable switch Q2 is not turned on, the first DC power supply outputs a high-level signal to the fault detection terminal of the drive chip U1 through the fifth resistor R5. F/S.

In practical applications, the first resistor R1, the second resistor R2, and the third resistor in the motor overvoltage protection circuit can be set reasonably according to the setting requirements of the overvoltage protection threshold of the bus voltage of the DC brushless motor and the circuit structure requirements. R3, the resistance of the fourth resistor R4, the fifth resistor R5, and the transistor selection of the first controllable switch Q1, the second controllable switch Q2, it should be noted that the first controllable switch Q1, the second controllable switch The control switch Q2 can be replaced by a triode or other switching devices with the same working principle as the triode, and the selection of other peripheral devices can be redesigned to achieve the same switching function.

The protection function mechanism of the above-mentioned motor drive chip U1 is that when the fault detection terminal F/S is a low level signal, the drive chip U1 works normally and outputs 6 PWM pulse signals to drive the motor to operate normally; when the fault detection terminal F/S When it is high, the driver chip U1 considers that it has triggered a fault, and will automatically turn off the 6-channel PWM pulse signal to stop the motor. It should be noted that the protection mechanism of the motor drive chip U1 is the common knowledge of the motor drive chip U1, which will not be repeated here.

In practical applications, the working principle of the above-mentioned motor overvoltage protection circuit is as follows:

Specifically, when the DC bus voltage applied to the DC brushless motor is within the normal voltage range of the motor, since the DC bus voltage does not reach the set overvoltage protection threshold, the control terminal of the first controllable switch Q1 receives The voltage of the motor bus voltage acquisition signal VBUS divided by the first resistor R1 and the second resistor R2 is less than the conduction voltage of the first controllable switch Q1, the first controllable switch Q1 is not conducting, and the second controllable switch Q2 The base of the second controllable switch Q1 is connected to the collector of the first controllable switch Q1. Since the first controllable switch Q1 is not turned on, the base of the second controllable switch Q2 is equivalent to connecting to a 5V power supply, so that the second controllable switch Q2 Turn on, the collector of the second controllable switch Q2 outputs a low-level signal to the fault detection terminal F/S of the drive chip U1, the drive chip U1 works normally, outputs 6 PWM pulse signals, and the drive motor runs normally; When the DC bus voltage of the brushless DC motor exceeds the set overvoltage protection threshold, the motor bus voltage collection signal VBUS received by the control terminal of the first controllable switch Q1 is divided by the first resistor R1 and the second resistor R2. The voltage is greater than the turn-on voltage of the first controllable switch Q1, the first controllable switch Q1 is turned on, the base of the second controllable switch Q2 is connected to the collector of the first controllable switch Q1, because the first controllable switch Q1 The switch Q1 is turned on, the base of the second controllable switch Q2 is equivalent to ground, so the second controllable switch Q2 is not turned on, and the collector of the second controllable switch Q2 is equivalent to connecting to a 5V DC power supply and directly outputting high power The flat signal is sent to the fault detection terminal F/S of the drive chip U1. The drive chip U1 considers that the fault is triggered, and will automatically turn off the 6 PWM pulse signals to stop the motor from running, thereby realizing the overvoltage protection function of the motor DC bus.

Through the cooperation of the above-mentioned various components, the motor overvoltage protection circuit provided by the embodiment of the present application, when the bus voltage value of the motor exceeds the high voltage protection threshold of the motor itself, the control terminal of the first controllable switch Q1 receives the bus voltage of the motor The acquisition signal triggers the first controllable switch Q1 to turn on. After the first controllable switch Q1 is turned on, the control terminal of the second controllable switch Q2 is grounded, the second controllable switch Q2 is not turned on, and the second controllable switch Q2 is turned on. The two terminals output high level to the fault detection terminal F/S of the drive chip U1 of the motor. The drive chip U1 triggers the fault protection and stops outputting the drive signal to the motor. The motor stops, thereby realizing the overvoltage protection of the motor. The embodiment of the application provides The motor overvoltage protection circuit has the characteristics of simple circuit structure, low cost, and wide application range. The overvoltage protection is realized by using the inherent protection function of the driver chip U1, which does not occupy the existing working circuit ports, and reduces the overvoltage protection function. The requirement for chip resources does not affect the existing protection functions of the circuit.

Figure 2 shows a schematic structural diagram of a motor undervoltage protection circuit provided by an embodiment of the present application. As shown in Figure 1, the motor undervoltage protection circuit includes: a third controllable switch Q3, and a control terminal of the third controllable switch Q3 Receiving the bus voltage collection signal VBUS of the motor, the first end is respectively connected to the fault detection end F/S and high level of the drive chip U1 of the motor, and the second end is grounded. In practical applications, the aforementioned high level is provided by the third DC power supply.

Specifically, in one embodiment, as shown in FIG. 2, the aforementioned motor undervoltage protection circuit further includes: a sixth resistor R6, a seventh resistor R7, and a third capacitor C3, wherein one end of the sixth resistor R6 receives the bus The other end of the voltage acquisition signal VBUS is connected to the third controllable switch Q3, one end of the third capacitor C3, and one end of the seventh resistor R7, and the other end of the seventh resistor R7 is grounded to the other end of the third capacitor C3. In practical applications, the above-mentioned third capacitor C3 and second capacitor C2 function as filtering.

Specifically, in one embodiment, as shown in FIG. 2, the aforementioned motor undervoltage protection circuit further includes: a third DC power source and an eighth resistor R8, wherein the third DC power source passes through the eighth resistor R8 and the third resistor R8. The first end of the control switch Q3 is connected. In practical applications, the third DC power supply is a 5V power supply. When the third controllable switch Q3 is not turned on, the third DC power supply outputs a high-level signal to the fault detection terminal F of the driving chip U1 through the eighth resistor R8. /S.

In practical applications, the sixth resistor R6, seventh resistor R7, and eighth resistor in the above motor overvoltage protection circuit can be set reasonably according to the setting requirements of the overvoltage protection threshold of the bus voltage of the DC brushless motor and the circuit structure requirements. The resistance of R8, and the selection of the transistor of the third controllable switch Q3, it should be noted that the third controllable switch Q3 can be replaced by a transistor or other switching devices with the same working principle as the transistor, and the periphery is redesigned Selection of other devices to achieve the same switching function.

In practical applications, the working principle of the above-mentioned motor undervoltage protection circuit is as follows:

Specifically, when the DC bus voltage applied to the DC brushless motor is within the normal voltage range of the motor, since the DC bus voltage does not reach the set overvoltage protection threshold, the control terminal of the third controllable switch Q3 receives The voltage of the motor bus voltage acquisition signal VBUS after being divided by the sixth resistor R6 and the seventh resistor R7 is greater than the turn-on voltage of the third controllable switch Q3, the third controllable switch Q3 is turned on, and the third controllable switch Q3 The collector is equivalent to ground, the collector of the third controllable switch Q3 outputs a low-level signal to the fault detection terminal F/S of the drive chip U1, the drive chip U1 works normally, outputs 6 PWM pulse signals, and the drive motor runs normally; When the DC bus voltage applied to the brushless DC motor is lower than the set under-voltage protection threshold, the motor bus voltage collection signal VBUS received by the control terminal of the third controllable switch Q3 passes through the sixth resistor R6 and the seventh resistor. The voltage divided by R7 is less than the conduction voltage of the third controllable switch Q3, the third controllable switch Q3 is not conducting, and the collector of the third controllable switch Q3 is equivalent to connecting to a 5V DC power supply and directly outputting a high level The signal is sent to the fault detection terminal F/S of the drive chip U1, and the drive chip U1 considers that the fault is triggered, and will automatically turn off the 6 PWM pulse signals to stop the motor from running, thereby realizing the under-voltage protection function of the motor DC bus.

In the motor undervoltage protection circuit provided by the embodiment of the application, when the bus voltage value of the motor exceeds the low voltage protection threshold of the motor itself, the control terminal of the third controllable switch Q3 receives the bus voltage collection signal of the motor less than the third controllable switch Q3 The third controllable switch Q3 is not conductive, the second controllable switch Q2 is not conductive, and the first terminal of the third controllable switch Q3 outputs a high level to the fault detection terminal F of the drive chip U1 of the motor /S, the drive chip U1 triggers fault protection, stops outputting a drive signal to the motor, and the motor stops, thereby realizing the undervoltage protection of the motor. The motor undervoltage protection circuit provided by the embodiment of the present application has a simple circuit structure, low cost, and wide application range. Features: By using the inherent protection function of the driver chip U1 to realize under-voltage protection, it will not occupy the existing working circuit ports, reducing the requirement of the under-voltage protection function on chip resources, and without affecting the existing protection functions of the circuit.

FIG. 3 shows a schematic structural diagram of a motor voltage protection circuit provided by an embodiment of the present application. As shown in FIG. 3, the motor voltage protection circuit includes: the motor overvoltage protection circuit 1 provided by the foregoing embodiment of the present application and the foregoing embodiment The motor undervoltage protection circuit 2. For details of the motor overvoltage protection circuit 1 and the motor undervoltage protection circuit 2, please refer to the relevant description of the above-mentioned embodiment of the present application, and will not be repeated here.

Specifically, in an embodiment, as shown in FIG. 3, the above-mentioned motor voltage protection circuit further includes: a signal acquisition circuit 3, the signal acquisition circuit 3 includes three series-connected resistors R11, R12, R13, a ninth resistor R9, The tenth resistor R10 and the fourth capacitor C4, wherein the bus voltage VDC of the motor is connected in series with resistors R11, R12, and R13, respectively, connected to one end of the ninth resistor R9 and one end of the tenth resistor R10, and the other end of the tenth resistor R10 Connected to one end of the fourth capacitor C4, the control end of the first controllable switch Q1, and the control end of the third controllable switch Q3, respectively, to output the motor bus voltage acquisition signal VBUS, the other end of the ninth resistor R9 and the fourth capacitor C4 Connect the other end to ground. In practical applications, because the bus voltage of the brushless DC motor is a relatively large voltage value, the bus voltage VDC cannot be directly connected to the input motor voltage protection circuit as the bus voltage acquisition signal VBUS, and through each of the above signal acquisition circuits The voltage value after the resistance is divided is used as the bus voltage collection signal VBUS of the motor voltage protection circuit. It should be noted that the above-mentioned signal acquisition circuit in the embodiment of the present application is illustrated by taking three series resistors as an example. In practical applications, the number, resistance and package size of the series resistors can be set as required. The application is not limited to this.

Specifically, in an embodiment, as shown in FIG. 3, the above-mentioned motor voltage protection circuit further includes: a comparator U2. The input terminal of the comparator U2 is connected to the second terminal and the third terminal of the second controllable switch Q2, respectively. The first terminal of the control switch Q3 is connected, and the output terminal of the comparator U2 is connected with the fault detection terminal F/S of the driving chip U1 of the motor. In practical applications, in order to simplify the circuit structure of the fault detection terminal F/S of the driver chip U1, the level signals output by the motor overvoltage protection circuit and the motor undervoltage protection circuit are output to the driver chip U1 after passing through the comparator U2. The fault detection terminal F/S, that is, as long as the level signal output by one of the above-mentioned motor overvoltage protection circuit and motor undervoltage protection circuit is a high level signal, the comparator U2 outputs a high level signal to trigger the drive chip U1 pair The motor is shut down for protection. It should be noted that the aforementioned comparator U2 can also be implemented by using a logic chip with the same function, and this application is not limited thereto.

The motor voltage protection circuit provided in the embodiments of the application realizes overvoltage protection and undervoltage protection of the motor. The motor voltage protection circuit provided in the embodiments of the application has the characteristics of simple circuit structure, low cost, and wide application range. The inherent protection function of the chip U1 realizes over-voltage protection and under-voltage protection, and does not occupy the existing working circuit ports, which reduces the requirements for chip resources of the over-voltage protection function and the under-voltage protection function, and does not affect the existing circuit The protection function. Furthermore, by designing the high-voltage protection threshold and low-voltage protection threshold of the motor bus voltage, the protection function of the drive chip U1 is triggered to realize the shutdown protection of the motor and protect the motor and components in a safe working state. When the working voltage returns to the normal working voltage, the motor returns to the normal working state.

An embodiment of the present application also provides a motor, which includes the motor voltage protection circuit provided in the foregoing embodiment of the present application. For details, please refer to the relevant description of the above-mentioned embodiment of the present application, which will not be repeated here.

The motor provided in the embodiment of the application realizes over-voltage protection and under-voltage protection of the motor. In the motor provided in the embodiment of the application, the voltage protection circuit in the motor has the characteristics of simple circuit structure, low cost, and wide application range. The inherent protection function of the driver chip realizes over-voltage protection and under-voltage protection, does not occupy the existing working circuit ports, reduces the requirements of the over-voltage protection function and the under-voltage protection function on chip resources, and does not affect the existing circuit The protection function.

Although the embodiments of the present application are described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the application, and such modifications and variations fall within the scope of the appended claims. Within the limited range.

Claims

A motor overvoltage protection circuit is characterized in that it comprises:

A first controllable switch, the control terminal of the first controllable switch receives the bus voltage collection signal of the motor, the first terminal is grounded, and the second terminal is connected to a high level;

A second controllable switch, the control terminal of the second controllable switch is connected to the second terminal of the first controllable switch, the first terminal is grounded, and the second terminal is respectively connected to the fault detection terminal of the drive chip of the motor And high level connection.
The motor overvoltage protection circuit according to claim 1, further comprising: a first resistor, a second resistor, and a first capacitor, wherein:

One end of the first resistor receives the bus voltage collection signal, and the other end is respectively connected to the control end of the first controllable switch, one end of the first capacitor, and one end of the second resistor. The second resistor The other end of and the other end of the first capacitor are grounded.
The motor overvoltage protection circuit according to claim 1, further comprising: a first DC power supply, a third resistor, and a fourth resistor, wherein:

The DC power supply is connected to one end of the third resistor, and the other end of the third resistor is respectively connected to the second end of the first controllable switch and one end of the fourth resistor. The fourth resistor The other end of is connected to the control end of the second controllable switch.
The motor overvoltage protection circuit according to claim 1, further comprising: a second DC power supply, a fifth resistor, and a second capacitor, wherein:

The second DC power supply is connected to the second end of the second controllable switch through the fifth resistor, one end of the second capacitor is connected to the first channel of the second controllable switch, and the other end is grounded .
A motor undervoltage protection circuit is characterized in that it comprises:

The third controllable switch, the control terminal of the third controllable switch receives the bus voltage collection signal of the motor, the first terminal is respectively connected with the fault detection terminal and the high level of the driving chip of the motor, and the second terminal is grounded.
The motor undervoltage protection circuit according to claim 5, further comprising: a sixth resistor, a seventh resistor, a third capacitor, a third DC power supply, and an eighth resistor, wherein:

One end of the sixth resistor receives the bus voltage collection signal, and the other end is respectively connected to the third controllable switch, one end of the third capacitor, and one end of the seventh resistor. The other end is grounded to the other end of the third capacitor;

The third DC power source is connected to the first end of the third controllable switch through the eighth resistor.
A motor voltage protection circuit, characterized by comprising: the motor overvoltage protection circuit according to any one of claims 1-4 and the motor undervoltage protection circuit according to any one of claims 5-6.
The motor voltage protection circuit according to claim 7, further comprising: a signal acquisition circuit, the signal acquisition circuit comprising a plurality of series-connected resistors, a ninth resistor, a tenth resistor, and a fourth capacitor, wherein,

The bus voltage of the motor is connected to the plurality of resistors connected in series and then respectively connected to one end of the ninth resistor and one end of the tenth resistor, and the other end of the tenth resistor is respectively connected to the fourth capacitor One end of the first controllable switch and the control end of the third controllable switch are connected, and the other end of the ninth resistor is connected to the other end of the fourth capacitor and then grounded.
The motor voltage protection circuit according to claim 7, further comprising: a comparator, the input terminal of the comparator is respectively connected to the second terminal of the second controllable switch and the third controllable switch The first terminal of the comparator is connected, and the output terminal of the comparator is connected to the fault detection terminal of the drive chip of the motor.
A motor, characterized in that the motor comprises the motor voltage protection circuit according to any one of claims 7-9.