IPM protection device, motor and IPM protection method thereof

Abstract

The present invention discloses an IPM protection device, a motor and an IPM protection method thereof, the device comprising: a current sampling circuit, a first overcurrent protection circuit, a second overcurrent protection circuit and a controller; wherein the current sampling circuit is used to collect the three-phase current of the motor driven by the IPM to be protected, and output a first output signal when the current sampling circuit is normal, or output a second output signal when the current sampling circuit is abnormal; the first overcurrent protection circuit is used to implement overcurrent protection for the IPM to be protected according to the first output signal under the control of the controller; the second overcurrent protection circuit is used to implement overcurrent protection for the IPM to be protected according to the second output signal under the control of the controller. The solution of the present invention can solve the problem of poor protection reliability caused by the internal power device of the IPM being burned after the operational amplifier chip in the current sampling circuit fails, thereby achieving the effect of improving protection reliability.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor protection, and specifically relates to an IPM protection device, a motor and an IPM protection method thereof, and more particularly to an IPM current sampling amplifier failure protection circuit (i.e., a motor three-phase current sampling amplifier failure protection circuit), a motor having the circuit, and an IPM current sampling amplifier failure protection method for the motor. Background Art

[0002] The three-phase current of the motor driven by the Intelligent Power Module (IPM) is sampled through resistors and detected through signal amplification. If the operational amplifier chip of the current sampling circuit fails, the MCU cannot obtain the real-time value of the three-phase current of the motor, and judges that the motor current is too low. The normal motor drive logic is turned on, and the PWM duty cycle is continuously increased, resulting in a continuous increase in the actual current of the motor, which burns out the power devices inside the IPM. Summary of the invention

[0003] The purpose of the present invention is to provide an IPM protection device, a motor and an IPM protection method thereof in view of the above-mentioned defects, so as to solve the problem of poor protection reliability in the prior art that the internal power devices of the IPM are burned after the operational amplifier chip in the current sampling circuit fails, thereby achieving the effect of improving the protection reliability.

[0004] The present invention provides an IPM protection device, comprising: a current sampling circuit, a first overcurrent protection circuit, a second overcurrent protection circuit and a controller; wherein the current sampling circuit is used to collect the three-phase current of the motor driven by the IPM to be protected, and output a first output signal when the current sampling circuit itself is normal, or output a second output signal when the current sampling circuit itself is abnormal; the first overcurrent protection circuit is used to implement overcurrent protection for the IPM to be protected according to the first output signal under the control of the controller; the second overcurrent protection circuit is used to implement overcurrent protection for the IPM to be protected according to the second output signal under the control of the controller.

[0005] Optionally, the controller is also used to determine whether the IPM current sampling signal of the current sampling circuit is normal before the motor driven by the IPM to be protected is turned on; and, if the IPM current sampling signal is normal, start the normal driving logic of the motor to control the normal operation of the motor, and implement overcurrent protection for the IPM to be protected through the first overcurrent protection circuit when the first output signal is overcurrent; if the IPM current sampling signal is abnormal, shut down the normal driving logic of the motor to implement overcurrent protection for the IPM to be protected through the second overcurrent protection circuit.

[0006] Optionally, the current sampling circuit includes: a motor three-phase current sampling resistor, a first operational amplifier, a feedback resistor and a first pull-down resistor; wherein the motor three-phase current sampling resistor is arranged between the three-phase current collection end of the IPM to be protected and the non-inverting input end of the first operational amplifier; the feedback resistor is arranged between the output end of the first operational amplifier and the inverting input end of the first operational amplifier; the first pull-down resistor is arranged between the output end of the first operational amplifier and the first sampling port of the controller; the first operational amplifier is used to output a high-level signal when the difference between the first output signal received at its non-inverting input end and the first reference signal provided at its inverting end is greater than a first set value, otherwise output a low-level signal.

[0007] Optionally, the first overcurrent protection circuit includes: a sampling signal acquisition resistor and a second operational amplifier; wherein the sampling signal acquisition resistor is arranged between the output end of the current sampling circuit and the non-inverting input end of the second operational amplifier; the second operational amplifier is used to flip when the first output signal collected at its non-inverting input end is greater than the second reference signal provided by its inverting input end, and output a first overcurrent protection signal that changes from a low-level signal to a high-level signal to the overcurrent protection end of the IPM to be protected; the controller is also used to shut down the normal drive logic of the motor according to the first overcurrent protection signal that changes from a low-level signal to a high-level signal to achieve overcurrent protection for the IPM to be protected.

[0008] Optionally, the second overcurrent protection circuit includes: an integration circuit and a transistor drive circuit; wherein the integration circuit is arranged between the output end of the current sampling circuit and the input end of the transistor drive circuit, and is used to output an integrated low-level signal when the second output signal output by the current sampling circuit is a low-level signal, and vice versa to output an integrated high-level signal; the transistor drive circuit is arranged between the output end of the integration circuit and the second sampling port of the controller, and is used to output a low-level signal when the integration circuit outputs a low-level signal; the controller is also used to shut down the normal drive logic of the motor to achieve overcurrent protection for the IPM to be protected when the transistor drive circuit outputs a low-level signal.

[0009] Optionally, the integration circuit includes: a first resistor, a second resistor, a third operational amplifier and a capacitor; wherein the first resistor is arranged between the output end of the current sampling circuit and the inverting input end of the third operational amplifier; the second resistor is arranged at the non-inverting input end of the third operational amplifier; and the capacitor is arranged between the output end of the third operational amplifier and the inverting input end of the third operational amplifier.

[0010] Optionally, the transistor drive circuit includes: a current limiting resistor, a transistor and a second pull-down resistor; wherein the current limiting resistor is arranged between the output end of the integration circuit and the base of the transistor; the transistor includes: a PNP type transistor; the second pull-down resistor is arranged at the emitter of the transistor; the emitter of the transistor is connected to the second sampling port of the controller; and the collector of the transistor is connected to a set DC power supply.

[0011] Matching the above device, the present invention further provides a motor, comprising: the above-mentioned IPM protection device.

[0012] To match the above-mentioned motor, the present invention provides an IPM protection method for a motor on another aspect, comprising: collecting the three-phase current of the motor driven by the IPM to be protected through a current sampling circuit, and outputting a first output signal when the motor itself is normal, or outputting a second output signal when the motor itself is abnormal; implementing overcurrent protection for the IPM to be protected according to the first output signal through a first overcurrent protection circuit; and implementing overcurrent protection for the IPM to be protected according to the second output signal through a second overcurrent protection circuit.

[0013] Optionally, it also includes: before the motor driven by the IPM to be protected is turned on, determining whether the IPM current sampling signal of the current sampling circuit is normal; and if the IPM current sampling signal is normal, turning on the normal driving logic of the motor to control the normal operation of the motor, and realizing overcurrent protection of the IPM to be protected through the first overcurrent protection circuit when the first output signal is overcurrent; if the IPM current sampling signal is abnormal, turning off the normal driving logic of the motor to realize overcurrent protection of the IPM to be protected through the second overcurrent protection circuit.

[0014] Optionally, the three-phase current of the motor driven by the IPM to be protected is collected through the current sampling circuit, including: through the first operational amplifier, a high-level signal is output when the difference between the first output signal received at its non-phase input terminal and the first reference signal provided at its inverting terminal is greater than a first set value, and a low-level signal is output otherwise.

[0015] Optionally, through the first overcurrent protection circuit, overcurrent protection of the IPM to be protected is implemented according to the first output signal, including: through the second operational amplifier, the first output signal collected at its non-phase input terminal is greater than the second reference signal provided at its inverting input terminal, and flipped, and output the first overcurrent protection signal that is changed from a low-level signal to a high-level signal to the overcurrent protection terminal of the IPM to be protected; according to the first overcurrent protection signal that is changed from a low-level signal to a high-level signal, the normal drive logic of the motor is turned off to implement overcurrent protection of the IPM to be protected.

[0016] Optionally, through the second overcurrent protection circuit, overcurrent protection of the IPM to be protected is implemented according to the second output signal, including: through an integration circuit, when the second output signal output by the current sampling circuit is a low-level signal, outputting an integrated low-level signal, otherwise outputting an integrated high-level signal; through a transistor drive circuit, when the integration circuit outputs a low-level signal, outputting a low-level signal; when the transistor drive circuit outputs a low-level signal, shutting down the normal drive logic of the motor to implement overcurrent protection of the IPM to be protected.

[0017] The solution of the present invention solves the problem of internal power devices of the IPM being burned out after the operational amplifier chip in the current sampling circuit fails by forming a protection circuit for failure of the motor three-phase current sampling operational amplifier by an integration circuit and a transistor drive circuit, thereby ensuring normal operation and protection safety when the sampling circuit fails, having high reliability and being conducive to extending the service life of the IPM.

[0018] Furthermore, the solution of the present invention forms a protection circuit for failure of the motor three-phase current sampling operational amplifier by an integration circuit and a transistor drive circuit. After the current sampling circuit fails, the output signal of the sampling circuit drives the transistor T to turn on after being acted upon by the integration circuit. The MCU recognizes the overcurrent protection signal to shut down the motor drive logic and lock the system. This can solve the problem of power devices inside the IPM module being burned out after the current sampling circuit fails, thereby improving protection reliability.

[0019] Furthermore, the scheme of the present invention detects whether the IPM current sampling signal is abnormal before the motor is started through a protection circuit composed of an integration circuit and a transistor drive circuit; when the IPM current sampling circuit is abnormal, the motor drive logic is turned off, the fault is determined, and the system is locked, thereby protecting the internal power devices of the IPM from damage, with high protection reliability and good safety.

[0020] Therefore, the scheme of the present invention forms a protection circuit for failure of the motor three-phase current sampling operational amplifier by adding an integration circuit and a transistor driving circuit on the basis of the traditional motor three-phase current sampling circuit, thereby solving the problem of poor protection reliability in the prior art that the internal power device of the IPM is burned after the operational amplifier chip in the current sampling circuit fails. Thus, the defects of poor protection reliability, poor safety and short service life in the prior art are overcome, and the beneficial effects of good protection reliability, good safety and long service life are achieved.

[0021] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention.

[0022] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic structural diagram of an embodiment of an IPM protection device of the present invention;

[0024] Figure 2 It is a structural diagram of a traditional motor three-phase current sampling circuit;

[0025] Figure 3 It is a structural schematic diagram of an embodiment of an IPM protection device of the present invention, specifically a structural schematic diagram of an embodiment of a protection circuit for failure of a current sampling operational amplifier;

[0026] Figure 4 A schematic diagram of a flow chart of an embodiment of an IPM protection method for a motor of the present invention;

[0027] Figure 5 It is a flow chart of an embodiment of determining whether the normal driving logic of the motor is turned on or off according to whether the IPM current sampling signal of the current sampling circuit is normal in the method of the present invention;

[0028] Figure 6 It is a flow chart of an embodiment of implementing overcurrent protection of the IPM to be protected by the first overcurrent protection circuit 20 according to the first output signal in the method of the present invention;

[0029] Figure 7 The present invention is a flowchart of an embodiment of implementing overcurrent protection for an IPM to be protected according to the second output signal by the second overcurrent protection circuit in the method of the present invention.

[0030] In conjunction with the accompanying drawings, the reference numerals in the embodiments of the present invention are as follows:

[0031] 10 - current sampling circuit; 20 - first overcurrent protection circuit; 30 - second overcurrent protection circuit; 40 - controller (such as MCU). DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] According to an embodiment of the present invention, an IPM protection device is provided. Figure 1The schematic diagram of the structure of an embodiment of the device of the present invention is shown. The IPM protection device may include: a current sampling circuit 10 (such as a conventional motor three-phase current sampling circuit), a first overcurrent protection circuit 20, a second overcurrent protection circuit 30 (such as a motor three-phase current sampling operational amplifier failure protection circuit composed of an integration circuit and a transistor drive circuit) and a controller 40 (such as the controller 40 of the IPM to be protected, which may be an MCU, etc.).

[0034] Specifically, the current sampling circuit 10 can be used to collect the three-phase current of the motor driven by the IPM to be protected when the current sampling circuit 10 itself is normal, and output a first output signal (such as the output signal U0 when the operational amplifier A1 is normal) when the current sampling circuit itself is normal, or output a second output signal (such as the output signal U0 when the operational amplifier A1 is abnormal) when the current sampling circuit itself is abnormal.

[0035] Optionally, the current sampling circuit 10 may include: a motor three-phase current sampling resistor (such as resistors R1 and R2), a first operational amplifier (such as operational amplifier A1), a feedback resistor (such as resistor R4) and a first pull-down resistor (such as resistor R5).

[0036] Specifically, the motor three-phase current sampling resistor is arranged between the three-phase current collection end of the IPM to be protected and the in-phase input end of the first operational amplifier, and can be used to collect the three-phase current of the motor driven by the IPM to be protected.

[0037] Specifically, the feedback resistor is arranged between the output terminal of the first operational amplifier and the inverting input terminal of the first operational amplifier, and can be used to provide a reference signal for the inverting terminal of the first operational amplifier.

[0038] Specifically, the first pull-down resistor is arranged between the output end of the first operational amplifier and the first sampling port of the controller 40 .

[0039] Specifically, the first operational amplifier can be used to output a high-level signal when the difference between the first output signal received at its non-inverting input terminal and the first reference signal provided at its inverting terminal (such as the first reference signal determined by resistors R3 and R4) is greater than a first set value, and output a low-level signal otherwise.

[0040] For example: Figure 2 or Figure 3 As shown, resistors R1 and R2 are motor three-phase current sampling resistors, and resistor R4 is a feedback resistor; operational amplifier A1 is a comparator, and its function is to make a difference between the current sampling signal at the non-inverting input terminal and the signal at the inverting terminal. If the difference is greater than 0, a high level is output, otherwise a low level is output; resistor R5 is a pull-down resistor of the chip MCU sampling port.

[0041] Therefore, a current sampling circuit is formed by the motor three-phase current sampling resistor, the first operational amplifier, the feedback resistor and the first pull-down resistor, which has a simple structure and can ensure the reliability and accuracy of the collection.

[0042] Specifically, the first overcurrent protection circuit 20 is arranged between the output end of the current sampling circuit 10 and the overcurrent protection end (i.e., the OC end) of the IPM to be protected, and can be used to implement overcurrent protection of the IPM to be protected according to the first output signal under the control of the controller 40. For example, through the first overcurrent protection circuit 20, when the current sampling circuit 10 can normally acquire the three-phase current, the overcurrent protection of the IPM to be protected can be implemented according to the acquired three-phase current, i.e., the first output signal.

[0043] Optionally, the first overcurrent protection circuit 20 may include: a sampling signal acquisition resistor (such as resistors R6 and R7) and a second operational amplifier (such as operational amplifier A2).

[0044] Specifically, the sampling signal acquisition resistor is arranged between the output end of the current sampling circuit 10 and the non-inverting input end of the second operational amplifier, and can be used to collect the first output signal output by the current sampling circuit 10 .

[0045] Specifically, the second operational amplifier can be used to detect that the first output signal collected at its in-phase input terminal is greater than the second reference signal (such as V F ), and output a first over-current protection signal which is changed from a low-level signal to a high-level signal to the over-current protection terminal (i.e., the OC terminal) of the IPM to be protected.

[0046] Specifically, the controller 40 can also be used to shut down the normal drive logic of the motor (such as a pre-set normal drive logic) to achieve overcurrent protection for the IPM to be protected according to the first overcurrent protection signal that changes from a low level signal to a high level signal when the second operational amplifier outputs the first overcurrent protection signal that changes from a low level signal to a high level signal.

[0047] For example: Figure 2 or Figure 3 As shown, resistors R6 and R7 are sampling resistors, which collect whether the signal output by op amp A1 is greater than the voltage V F ; The function of op amp A2 is the same as op amp A1, V F is a certain reference value, and its value is different in different circuits. The three-phase current sampling circuit of the motor is sampled by the sampling resistor and amplified by the operational amplifier to achieve detection. When the motor current is too large, the sampling resistor R7 voltage is greater than the bias voltage VF , op amp A2 flips, and its output signal OC changes from low level to high level. The MCU recognizes the hardware overcurrent protection high level signal OC and will shut down the motor drive logic, lock the system, and protect the internal power devices of the IPM from being burned.

[0048] Therefore, the first overcurrent protection circuit is formed by the sampling signal acquisition resistor and the second operational amplifier, which can reliably implement overcurrent protection for the IPM to be protected when the current sampling circuit is normal, and has a simple structure and good safety.

[0049] Specifically, the second overcurrent protection circuit 30 is provided between the output end of the current sampling circuit 10 and the controller 40 (such as the controller 40 of the IPM to be protected), and can be used to implement overcurrent protection of the IPM to be protected according to the second output signal under the control of the controller 40. For example: through the second overcurrent protection circuit 30, when the current sampling circuit 10 fails and cannot normally collect the three-phase current, the overcurrent protection of the IPM to be protected is implemented according to the second output signal output by the current sampling circuit 10 in this case.

[0050] For example: Figure 3 As shown in the figure, the protection circuit for failure of the motor three-phase current sampling amplifier is composed of an integration circuit and a transistor drive circuit. After the current sampling circuit fails, the output signal of the amplifier A1 drives the transistor T to conduct after the integration circuit acts on it. The MCU recognizes the overcurrent protection signal and shuts down the motor drive logic and locks the system, which can solve the problem of the power device inside the IPM module being burned after the current sampling circuit fails.

[0051] Therefore, the three-phase current of the motor driven by the IPM to be protected is collected through the current sampling circuit, and the overcurrent protection of the IPM to be protected is realized according to the three-phase circuit through the first overcurrent protection circuit when the current sampling circuit is normal, and the overcurrent protection of the IPM to be protected is realized according to the output signal of the current sampling circuit when the current sampling circuit is abnormal, thereby realizing double overcurrent protection for the IPM to be protected, and greatly improving the reliability and safety of the overcurrent protection.

[0052] Optionally, the second overcurrent protection circuit 30 may include: an integration circuit and a transistor driving circuit.

[0053] Specifically, the integration circuit is arranged between the output end of the current sampling circuit 10 and the input end of the transistor driving circuit, and can be used to detect the second output signal output by the current sampling circuit 10 when the current sampling circuit 10 is abnormal, and output the integrated low-level signal when the second output signal output by the current sampling circuit 10 is a low-level signal, otherwise it outputs the integrated high-level signal.

[0054] For example: Figure 3 The example shown in the figure is compared with the original motor three-phase current sampling circuit (such as Figure 2 The example shown) has the function of dual over-current protection; if the comparator A1 is damaged, its output signal is continuously pulled to a low level by the pull-down resistor R5, the output signal OC of the operational amplifier A2 is continuously at a low level, the original current sampling circuit fails, the motor current continues to increase and breaks down the IPM module, at this time the integration circuit acts as a detection circuit to prevent the motor current from being too large and breaking down the IPM module.

[0055] For example: Figure 3 The figure shows the basic structure of the protection circuit for the failure of the current sampling amplifier. Before the motor starts, the output signal U0 of the amplifier A1 in the current sampling circuit is collected, and the overcurrent protection circuit composed of the integration circuit and the transistor amplifier circuit is used to realize the functional protection of the failure of the current sampling circuit. Among them, the sampling circuit output signal U0 is acted on by the integration circuit:

[0056]

[0057] At the moment of power-on, i.e., t1=0, the voltage signal U0(t1) on the capacitor is 0, so the output signal U1 of the integration circuit is:

[0058]

[0059] Among them, U1 is the output signal of the integration circuit, C is the negative feedback capacitor of the integration circuit, R8 is the input resistance of the inverting terminal of the operational amplifier A3, and U0 is the output signal of the operational amplifier A1, which is used to determine whether to drive the transistor T to turn on.

[0060] More optionally, the integration circuit may include: a first resistor (such as resistor R8), a second resistor (such as resistor R 11 ), a third operational amplifier (such as op amp A3) and a capacitor (such as capacitor C).

[0061] The first resistor is arranged between the output terminal of the current sampling circuit 10 and the inverting input terminal of the third operational amplifier. The second resistor is arranged at the non-inverting input terminal of the third operational amplifier, such as between the non-inverting input terminal of the third operational amplifier and ground. The capacitor is arranged between the output terminal of the third operational amplifier and the inverting input terminal of the third operational amplifier.

[0062] For example: Figure 3 As shown, op amp A3 is a comparator, and its function is similar to op amps A1 and A2; op amp A3 and resistors R8 and R 11And capacitor C form an analog integration circuit. When the input signal is low level, the integration circuit output U1 is low level, otherwise it is high level.

[0063] Thus, an integrating circuit is formed by the first resistor, the second resistor, the third operational amplifier and the capacitor, and has a simple structure and high reliability.

[0064] Specifically, the transistor driving circuit is arranged between the output end of the integration circuit and the second sampling port of the controller 40, and can be used to output a low-level signal when the integration circuit outputs a low-level signal.

[0065] For example, when the sampling circuit (such as the current sampling circuit 10) works normally, the operational amplifier A1 outputs a signal U0, whose amplitude is equal to the bias voltage V F The transistor amplifier circuit uses a PNP transistor, and the external conditions for its operation in the amplification state are that the emitter junction is forward biased and the collector junction is reverse biased. Therefore, U1 will drive the transistor to conduct. At this time, the transistor amplifier circuit outputs a signal U2 that is pulled up from a low level to a high level. The MCU recognizes that U2 is a high level and will ignore the protection signal and not act.

[0066] For example, when the sampling circuit (such as the current sampling circuit 10) fails, the output signal of the operational amplifier A1 continues to be a low level U0. Since the integration circuit is essentially a summing circuit, U0 is still a low level after the integration circuit acts, and its output signal U1 cannot drive the transistor to conduct. The output signal U2 of the transistor amplifier circuit is pulled down by the pull-down resistor R 10 The action changes suddenly from high level to low level, the MCU recognizes the hardware overcurrent protection signal U2, shuts down the normal drive logic of the motor, locks the system, protects the internal power devices of the IPM from being burned, and displays the fault code through the handheld operator or LCD screen.

[0067] More optionally, the transistor drive circuit may include: a current limiting resistor (such as resistor R9), a transistor (such as transistor T) and a second pull-down resistor (such as resistor R 10 ).

[0068] Wherein, the current limiting resistor is arranged between the output end of the integration circuit and the base of the transistor. The transistor may include: a PNP type transistor. The second pull-down resistor is arranged at the emitter of the transistor, such as between the emitter of the transistor and the ground. The emitter of the transistor is connected to the second sampling port of the controller 40, and the control signal output end of the controller 40 is connected to the control signal input end of the IPM to be protected. The collector of the transistor is connected to a set DC power supply (such as Vcc).

[0069] For example: Figure 3 As shown, resistor R9 is the current limiting resistor of transistor T, and resistor R 10 is a pull-down resistor.

[0070] Therefore, a transistor driving circuit is formed by the current limiting resistor, the transistor and the second pull-down resistor, which has a simple structure and high reliability and good safety in driving and protecting the IPM to be protected.

[0071] Specifically, the controller 40 can also be used to shut down the normal driving logic of the motor (such as a pre-set normal driving logic) to achieve overcurrent protection for the IPM to be protected when the transistor driving circuit outputs a low-level signal.

[0072] In specific use, the transistor drive circuit can also be used to conduct and output a high-level signal when the integration circuit outputs a high-level signal. The controller 40 can also be used to control the motor to operate normally according to normal drive logic when the transistor drive circuit outputs a high-level signal.

[0073] Therefore, by forming a second overcurrent protection circuit through an integration circuit and a transistor drive circuit, overcurrent protection of the IPM to be protected can be reliably achieved when the current sampling circuit is abnormal, which greatly improves the reliability and safety of the overcurrent protection, extends the service life of the IPM to be protected, and saves maintenance costs.

[0074] In an optional embodiment, the controller 40 can also be used to determine whether the IPM current sampling signal of the current sampling circuit 10 is normal before the motor driven by the IPM to be protected is turned on; and, if the IPM current sampling signal is normal, the normal driving logic of the motor (such as the pre-set normal driving logic) is turned on to control the normal operation of the motor, and when the first output signal is overcurrent (such as exceeding the set protection current of the IPM to be protected), overcurrent protection of the IPM to be protected is achieved through the first overcurrent protection circuit 20; or, if the IPM current sampling signal is abnormal, the normal driving logic of the motor (such as the pre-set normal driving logic) is turned off to achieve overcurrent protection of the IPM to be protected through the second overcurrent protection circuit 30.

[0075] For example: the protection circuit composed of the integration circuit and the transistor drive circuit detects whether the IPM current sampling signal is abnormal before the motor is turned on. When the IPM current sampling circuit is working normally, the normal motor drive logic can be turned on. When the IPM current sampling circuit is abnormal, the motor drive logic will be turned off, the fault will be determined, and the system will be locked, thereby protecting the internal power devices of the IPM from damage.

[0076] Therefore, the controller of the IPM to be protected controls the opening or closing of the normal driving logic of the motor according to whether the IPM current sampling signal of the current sampling circuit is normal, thereby ensuring the normal operation of the motor and realizing reliable protection of the motor in the event of overcurrent. The control method is simple, and both reliability and safety can be guaranteed.

[0077] After a large number of experimental verifications, the technical solution of the present invention is adopted, and a protection circuit for failure of the motor three-phase current sampling operational amplifier is formed by an integration circuit and a transistor drive circuit. This solves the problem of the internal power devices of the IPM being burned after the operational amplifier chip in the current sampling circuit 10 fails. This ensures normal operation and also ensures the protection safety when the sampling circuit fails. It has high reliability and is also beneficial to extending the service life of the IPM.

[0078] According to an embodiment of the present invention, a motor corresponding to the IPM protection device is also provided. The motor may include: the IPM protection device described above.

[0079] In an alternative embodiment, if Figure 2 The three-phase current sampling circuit of the motor shown. If the operational amplifier A1 fails, the MCU cannot detect whether the current sampling signal is abnormal before the motor starts, and will continue to maintain the normal driving logic of the motor and continue to increase the duty cycle of the PWM. When the actual current of the motor exceeds the protection current of the IPM module, the output signal of the operational amplifier A1 remains at a low level through the pull-down resistor R5, and cannot drive the operational amplifier A2 to flip, and the hardware overcurrent protection function fails, causing the internal power devices of the IPM to be burned. Based on this, the scheme of the present invention designs a protection circuit for the failure of the three-phase current sampling operational amplifier of the motor, which solves the problem of the internal power devices of the IPM being burned after the operational amplifier chip in the current sampling circuit fails.

[0080] In an alternative example, Figure 3 As shown, the scheme of the present invention designs a protection circuit for failure of the three-phase current sampling amplifier of the motor, which is composed of an integration circuit and a transistor drive circuit. After the current sampling circuit fails, the output signal of the amplifier A1 drives the transistor T to turn on after the integration circuit acts, and the MCU recognizes the overcurrent protection signal to turn off the motor drive logic and lock the system, which can solve the problem of the power device inside the IPM module being burned after the current sampling circuit fails.

[0081] Optionally, the solution of the present invention designs a protection circuit composed of an integration circuit and a transistor drive circuit to detect whether the IPM current sampling signal is abnormal before the motor is turned on. When the IPM current sampling circuit works normally, the normal motor drive logic can be turned on. When the IPM current sampling circuit is abnormal, the motor drive logic will be turned off, the fault will be determined, and the system will be locked, thereby protecting the internal power devices of the IPM from damage.

[0082] For example: this operation is performed by the protection circuit composed of the integration circuit and the transistor drive circuit. The current sampling amplifier fails and keeps outputting a low-level signal. At this time, the protection circuit composed of the integration circuit and the transistor drive circuit will be activated to protect the IPM module from burning due to the continuous increase in current. If the current sampling amplifier chip fails, that is, the current sampling signal is abnormal, at this time, the signal output by the current sampling circuit is a low level. If the chip is normal, the signal output is a high level. Therefore, the abnormality can be judged by the level of the current sampling amplifier output.

[0083] In an optional embodiment, it can be combined with Figure 2 and Figure 3 The examples shown are used to illustrate the specific implementation process of the solution of the present invention.

[0084] Figure 2 In the figure, resistors R1 and R2 are the three-phase current sampling resistors of the motor, and resistor R4 is the feedback resistor; op amp A1 is a comparator, which is used to make a difference between the current sampling signal at the in-phase input terminal and the signal at the inverting terminal. If the difference is greater than 0, it outputs a high level, otherwise it outputs a low level; resistor R5 is the pull-down resistor of the chip MCU sampling port, and resistors R6 and R7 are sampling resistors, which collect whether the signal output by op amp A1 is greater than the voltage V F ; The function of op amp A2 is the same as op amp A1, V F It is a certain reference value, and its value varies in different circuits.

[0085] Figure 2 This is a three-phase current sampling circuit for the motor. The three-phase current is sampled by the sampling resistor and amplified by the operational amplifier to achieve detection. When the motor current is too large, the voltage of the sampling resistor R7 is greater than the bias voltage V F , op amp A2 flips, and its output signal OC changes from low level to high level. The MCU recognizes the high level signal OC of the hardware overcurrent protection and turns off the motor drive logic, locking the system to protect the power devices inside the IPM from being burned. If the sampling circuit op amp chip A1 is damaged, its output signal remains at a low level through the pull-down resistor R5, and its output signal cannot drive the op amp A2 to flip. The MCU cannot recognize the high level signal OC of the hardware overcurrent protection, and then turns on the normal motor drive logic, causing the power devices inside the IPM to be burned.

[0086] In an alternative specific example, Figure 3 In the figure, op amp A3 is a comparator, and its function is similar to op amps A1 and A2; op amp A3 and resistors R8 and R 11 The analog integrator circuit is formed with capacitor C. When the input signal is low level, the output U1 of the integrator circuit is low level, otherwise it is high level. Resistor R9 is the current limiting resistor of transistor T, and resistor R 10 is a pull-down resistor.

[0087] Figure 3 The example shown in the figure is compared with the original motor three-phase current sampling circuit (such as Figure 2 The example shown) has the function of dual over-current protection; if the comparator A1 is damaged, its output signal is continuously pulled to a low level by the pull-down resistor R5, the output signal OC of the operational amplifier A2 is continuously at a low level, the original current sampling circuit fails, the motor current continues to increase and breaks down the IPM module, at this time the integration circuit acts as a detection circuit to prevent the motor current from being too large and breaking down the IPM module.

[0088] Overcurrent protection circuit implementation plan: Figure 3 The figure shows the basic structure of the protection circuit for the failure of the current sampling amplifier. Before the motor starts, the output signal U0 of the amplifier A1 in the current sampling circuit is collected, and the overcurrent protection circuit composed of the integration circuit and the transistor amplifier circuit is used to realize the functional protection of the failure of the current sampling circuit. Among them, the sampling circuit output signal U0 is acted on by the integration circuit:

[0089]

[0090] At the moment of power-on, i.e., t1=0, the voltage signal U0(t1) on the capacitor is 0, so the output signal U1 of the integration circuit is:

[0091]

[0092] Among them, U1 is the output signal of the integration circuit, C is the negative feedback capacitor of the integration circuit, R8 is the input resistance of the inverting terminal of the operational amplifier A3, and U0 is the output signal of the operational amplifier A1, which is used to determine whether to drive the transistor T to turn on.

[0093] Optionally, when the sampling circuit works normally, the operational amplifier A1 outputs a signal U0, whose amplitude is equal to the bias voltage V F The transistor amplifier circuit uses a PNP transistor, and the external conditions for its operation in the amplification state are that the emitter junction is forward biased and the collector junction is reverse biased. Therefore, U1 will drive the transistor to conduct. At this time, the transistor amplifier circuit outputs a signal U2 that is pulled up from a low level to a high level. The MCU recognizes that U2 is a high level and will ignore the protection signal and not act.

[0094] Among them, the MCU recognizes that U2 is at a high level and will ignore the protection signal and not take action. This can be achieved through software. The judgment will be set in the program. If U2 is at a high level, it will not take action. If it is at a low level, it will take action for protection.

[0095] Optionally, when the sampling circuit fails, the output signal of the operational amplifier A1 continues to be a low level U0. Since the integration circuit is essentially a summing circuit, U0 is still a low level after the integration circuit acts, and its output signal U1 cannot drive the transistor to turn on. The output signal U2 of the transistor amplifier circuit is pulled down by the pull-down resistor R 10 The action changes suddenly from high level to low level, the MCU recognizes the hardware overcurrent protection signal U2, shuts down the normal drive logic of the motor, locks the system, protects the internal power devices of the IPM from being burned, and displays the fault code through the handheld operator or LCD screen.

[0096] Compared with the motor three-phase current sampling circuit, it can solve the problem of module burning caused by failure of the current sampling circuit.

[0097] Since the processing and functions implemented by the motor of this embodiment are basically corresponding to the aforementioned Figures 1 to 3 The embodiments, principles and examples of the device shown are as follows. Therefore, for matters not fully described in the description of this embodiment, reference can be made to the relevant descriptions in the aforementioned embodiments, and no further elaboration will be given here.

[0098] After a large number of experimental verifications, the technical solution of the present invention is adopted. By forming a protection circuit for failure of the motor three-phase current sampling operational amplifier by an integration circuit and a transistor drive circuit, after the current sampling circuit 10 fails, the output signal of the sampling circuit drives the transistor T to turn on after the action of the integration circuit. The MCU recognizes the overcurrent protection signal to shut down the motor drive logic and lock the system. This can solve the problem of the power devices inside the IPM module being burned out after the current sampling circuit 10 fails, and improve the protection reliability.

[0099] According to an embodiment of the present invention, an IPM protection method for a motor corresponding to the motor is also provided. Figure 4 The flowchart of an embodiment of the method of the present invention is shown in FIG. The IPM protection method of the motor may include: steps S110 to S130.

[0100] At step S110, the current sampling circuit 10 collects the three-phase current of the motor driven by the IPM to be protected when the current sampling circuit 10 itself is normal, and outputs a first output signal (such as the output signal U0 when the operational amplifier A1 is normal) when the current sampling circuit itself is normal, or outputs a second output signal (such as the output signal U0 when the operational amplifier A1 is abnormal) when the current sampling circuit itself is abnormal.

[0101] Optionally, in step S110, the three-phase current of the motor driven by the IPM to be protected is collected through the current sampling circuit 10, which can mainly include: through the first operational amplifier, a high-level signal is output when the difference between the first output signal received at its non-phase input terminal and the first reference signal provided at its inverting terminal (such as the first reference signal determined by resistors R3 and R4) is greater than a first set value, and a low-level signal is output otherwise.

[0102] For example: Figure 2 or Figure 3 As shown, resistors R1 and R2 are motor three-phase current sampling resistors, and resistor R4 is a feedback resistor; operational amplifier A1 is a comparator, and its function is to make a difference between the current sampling signal at the non-inverting input terminal and the signal at the inverting terminal. If the difference is greater than 0, a high level is output, otherwise a low level is output; resistor R5 is a pull-down resistor of the chip MCU sampling port.

[0103] Therefore, a current sampling circuit is formed by the motor three-phase current sampling resistor, the first operational amplifier, the feedback resistor and the first pull-down resistor, which has a simple structure and can ensure the reliability and accuracy of the collection.

[0104] At step S120, the first overcurrent protection circuit 20 is provided between the output end of the current sampling circuit 10 and the overcurrent protection end (i.e., the OC end) of the IPM to be protected, and the overcurrent protection of the IPM to be protected is implemented according to the first output signal under the control of the controller 40 of the IPM to be protected. For example, through the first overcurrent protection circuit 20, when the current sampling circuit 10 can normally acquire the three-phase current, the overcurrent protection of the IPM to be protected can be implemented according to the acquired three-phase current, i.e., the first output signal.

[0105] Optionally, you can combine Figure 6 The method of the present invention is shown as a flow chart of an embodiment of implementing overcurrent protection for the IPM to be protected according to the first output signal by the first overcurrent protection circuit 20, further illustrating the specific process of implementing overcurrent protection for the IPM to be protected according to the first output signal by the first overcurrent protection circuit 20 in step S120, which may include: step S310 and step S320.

[0106] Step S310: The first output signal collected at the in-phase input terminal of the second operational amplifier is greater than the second reference signal (such as V F ), and output a first over-current protection signal which is changed from a low-level signal to a high-level signal to the over-current protection terminal (i.e., the OC terminal) of the IPM to be protected.

[0107] Step S320, through the controller 40 of the IPM to be protected, when the second operational amplifier outputs the first overcurrent protection signal that changes from a low level signal to a high level signal, according to the first overcurrent protection signal that changes from a low level signal to a high level signal, the normal drive logic of the motor (such as the pre-set normal drive logic) is turned off to achieve overcurrent protection for the IPM to be protected.

[0108] For example: Figure 2 or Figure 3 As shown, resistors R6 and R7 are sampling resistors, which collect whether the signal output by amplifier A1 is greater than the voltage V F ; The function of op amp A2 is the same as op amp A1, V F is a certain reference value, and its value is different in different circuits. The three-phase current sampling circuit of the motor is sampled by the sampling resistor and amplified by the operational amplifier to achieve detection. When the motor current is too large, the sampling resistor R7 voltage is greater than the bias voltage V F , op amp A2 flips, and its output signal OC changes from low level to high level. The MCU recognizes the hardware overcurrent protection high level signal OC and will shut down the motor drive logic, lock the system, and protect the internal power devices of the IPM from being burned.

[0109] Therefore, the first overcurrent protection circuit is formed by the sampling signal acquisition resistor and the second operational amplifier, which can reliably implement overcurrent protection for the IPM to be protected when the current sampling circuit is normal, and has a simple structure and good safety.

[0110] At step S130, the overcurrent protection of the IPM to be protected is implemented according to the second output signal under the control of the controller 40 of the IPM to be protected, by means of the second overcurrent protection circuit 30 provided between the output end of the current sampling circuit 10 and the controller 40 (such as the controller 40 of the IPM to be protected). For example, by means of the second overcurrent protection circuit 30, when the current sampling circuit 10 fails and cannot normally acquire the three-phase current, the overcurrent protection of the IPM to be protected is implemented according to the second output signal output by the current sampling circuit 10 in this case.

[0111] For example: Figure 3 As shown in the figure, the protection circuit for failure of the motor three-phase current sampling amplifier is composed of an integration circuit and a transistor drive circuit. After the current sampling circuit fails, the output signal of the amplifier A1 drives the transistor T to conduct after the integration circuit acts on it. The MCU recognizes the overcurrent protection signal and shuts down the motor drive logic and locks the system, which can solve the problem of the power device inside the IPM module being burned after the current sampling circuit fails.

[0112] Therefore, the three-phase current of the motor driven by the IPM to be protected is collected through the current sampling circuit, and the overcurrent protection of the IPM to be protected is realized according to the three-phase circuit through the first overcurrent protection circuit when the current sampling circuit is normal, and the overcurrent protection of the IPM to be protected is realized according to the output signal of the current sampling circuit when the current sampling circuit is abnormal, thereby realizing double overcurrent protection for the IPM to be protected, and greatly improving the reliability and safety of the overcurrent protection.

[0113] Optionally, you can combine Figure 7 The method of the present invention is shown as a flow chart of an embodiment of implementing overcurrent protection for the IPM to be protected by the second overcurrent protection circuit according to the second output signal, further illustrating the specific process of implementing overcurrent protection for the IPM to be protected by the second overcurrent protection circuit according to the second output signal, which may include: steps S410 to S430.

[0114] Step S410, by setting an integration circuit between the output end of the current sampling circuit 10 and the input end of the transistor driving circuit, the second output signal output by the current sampling circuit 10 is detected when the current sampling circuit 10 is abnormal, and when the second output signal output by the current sampling circuit 10 is a low-level signal, the integrated low-level signal is output, otherwise the integrated high-level signal is output.

[0115] Step S420 , outputting a low level signal when the integration circuit outputs a low level signal by means of a transistor driving circuit provided between the output end of the integration circuit and the second sampling port of the controller 40 .

[0116] Step S430, through the controller 40 of the IPM to be protected, when the transistor drive circuit outputs a low level signal, the normal drive logic of the motor (such as the pre-set normal drive logic) is turned off to achieve overcurrent protection for the IPM to be protected.

[0117] In the specific use process, the transistor drive circuit is also turned on and outputs a high-level signal when the integration circuit outputs a high-level signal. The controller 40 of the IPM to be protected is also used to control the motor to operate normally according to the normal drive logic when the transistor drive circuit outputs a high-level signal.

[0118] Therefore, by forming a second overcurrent protection circuit through an integration circuit and a transistor drive circuit, overcurrent protection of the IPM to be protected can be reliably achieved when the current sampling circuit is abnormal, which greatly improves the reliability and safety of the overcurrent protection, extends the service life of the IPM to be protected, and saves maintenance costs.

[0119] In an optional implementation, the method may further include: determining whether to turn on or off the normal driving logic of the motor according to whether the IPM current sampling signal of the current sampling circuit is normal.

[0120] Combine the following Figure 5 The method of the present invention is shown as a flow chart of an embodiment of determining whether the normal drive logic of the motor is turned on or off according to whether the IPM current sampling signal of the current sampling circuit is normal, further illustrating the specific process of determining whether the normal drive logic of the motor is turned on or off according to whether the IPM current sampling signal of the current sampling circuit is normal, which may include: steps S210 to S230.

[0121] Step S210, through the controller 40 of the IPM to be protected, before the motor driven by the IPM to be protected is turned on, it is determined whether the IPM current sampling signal of the current sampling circuit 10 is normal. And,

[0122] Step S220, if the IPM current sampling signal is normal, the normal driving logic of the motor (such as the pre-set normal driving logic) is turned on to control the normal operation of the motor, and when the first output signal is overcurrent (such as exceeding the set protection current of the IPM to be protected), overcurrent protection of the IPM to be protected is implemented through the first overcurrent protection circuit 20.

[0123] Step S230 , if the IPM current sampling signal is abnormal, the normal driving logic of the motor (such as the pre-set normal driving logic) is turned off to implement overcurrent protection for the IPM to be protected through the second overcurrent protection circuit 30 .

[0124] For example: the protection circuit composed of the integration circuit and the transistor drive circuit detects whether the IPM current sampling signal is abnormal before the motor is turned on. When the IPM current sampling circuit is working normally, the normal motor drive logic can be turned on. When the IPM current sampling circuit is abnormal, the motor drive logic will be turned off, the fault will be determined, and the system will be locked, thereby protecting the internal power devices of the IPM from damage.

[0125] Therefore, the controller of the IPM to be protected controls the opening or closing of the normal driving logic of the motor according to whether the IPM current sampling signal of the current sampling circuit is normal, thereby ensuring the normal operation of the motor and realizing reliable protection of the motor in the event of overcurrent. The control method is simple, and both reliability and safety can be guaranteed.

[0126] Since the processing and functions implemented by the method of this embodiment basically correspond to the embodiments, principles and examples of the aforementioned motor, for the details not fully described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments, and no further elaboration will be made here.

[0127] After a large number of tests and verifications, the technical solution of this embodiment is adopted, and the protection circuit composed of an integration circuit and a transistor drive circuit is used to detect whether the IPM current sampling signal is abnormal before the motor is turned on; when the IPM current sampling circuit is abnormal, the motor drive logic will be turned off, the fault will be determined, and the system will be locked, thereby protecting the internal power devices of the IPM from damage, with high protection reliability and good safety.

[0128] In summary, it is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0129] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. An IPM protection device, characterized in that: include: A current sampling circuit (10), a first overcurrent protection circuit (20), a second overcurrent protection circuit (30) and a controller (40); wherein: The current sampling circuit (10) comprises: a motor three-phase current sampling circuit; the current sampling circuit (10) is arranged at a three-phase current collection end of the IPM to be protected, and is used to collect the three-phase current of the motor driven by the IPM to be protected, and output a first output signal when the current sampling circuit itself is normal, or output a second output signal when the current sampling circuit itself is abnormal; The first overcurrent protection circuit (20) comprises: a sampling signal acquisition resistor and a second operational amplifier; the first overcurrent protection circuit (20) is arranged between the output end of the current sampling circuit (10) and the overcurrent protection end of the IPM to be protected, and is used to implement overcurrent protection for the IPM to be protected according to the first output signal under the control of the controller (40); The second overcurrent protection circuit (30) comprises: a protection circuit for failure of a motor three-phase current sampling operational amplifier composed of an integration circuit and a transistor drive circuit; the second overcurrent protection circuit (30) is arranged between the output end of the current sampling circuit (10) and the controller (40), and is used to implement overcurrent protection of the IPM to be protected according to the second output signal under the control of the controller (40); The controller (40) is further used to determine whether the IPM current sampling signal of the current sampling circuit (10) is normal before the motor driven by the IPM to be protected is turned on; and If the IPM current sampling signal is normal, the normal driving logic of the motor is started to control the normal operation of the motor, and when the first output signal is overcurrent, the first overcurrent protection circuit (20) is used to implement overcurrent protection for the IPM to be protected; If the IPM current sampling signal is abnormal, the normal driving logic of the motor is turned off to implement overcurrent protection for the IPM to be protected through the second overcurrent protection circuit (30).

2. The device according to claim 1, characterized in that The current sampling circuit (10) comprises: a motor three-phase current sampling resistor, a first operational amplifier, a feedback resistor and a first pull-down resistor; wherein: The motor three-phase current sampling resistor is arranged between the three-phase current collection terminal of the IPM to be protected and the in-phase input terminal of the first operational amplifier; The feedback resistor is arranged between the output terminal of the first operational amplifier and the inverting input terminal of the first operational amplifier; The first pull-down resistor is arranged between the output end of the first operational amplifier and the first sampling port of the controller (40); The first operational amplifier is used for outputting a high level signal when the difference between the first output signal received at its non-inverting input terminal and the first reference signal provided at its inverting terminal is greater than a first set value, and outputting a low level signal otherwise.

3. The device according to any one of claims 1-2, characterized in that: in, The sampling signal acquisition resistor is arranged between the output end of the current sampling circuit (10) and the in-phase input end of the second operational amplifier; The second operational amplifier is used to flip when the first output signal collected at its non-inverting input terminal is greater than the second reference signal provided at its inverting input terminal, and output a first overcurrent protection signal that changes from a low-level signal to a high-level signal to the overcurrent protection terminal of the IPM to be protected; The controller (40) is further used to shut down the normal driving logic of the motor to implement overcurrent protection for the IPM to be protected according to the first overcurrent protection signal that changes from a low-level signal to a high-level signal.

4. The device according to any one of claims 1-2, characterized in that: in, The integration circuit is arranged between the output end of the current sampling circuit (10) and the input end of the transistor driving circuit, and is used to output an integrated low-level signal when the second output signal output by the current sampling circuit (10) is a low-level signal, and vice versa to output an integrated high-level signal; The transistor driving circuit is arranged between the output end of the integration circuit and the second sampling port of the controller (40), and is used to output a low-level signal when the integration circuit outputs a low-level signal; The controller (40) is further used to shut down the normal driving logic of the motor to achieve overcurrent protection for the IPM to be protected when the transistor driving circuit outputs a low-level signal.

5. The device according to claim 3, characterized in that in, The integration circuit is arranged between the output end of the current sampling circuit (10) and the input end of the transistor driving circuit, and is used to output an integrated low-level signal when the second output signal output by the current sampling circuit (10) is a low-level signal, and vice versa to output an integrated high-level signal; The transistor driving circuit is arranged between the output end of the integration circuit and the second sampling port of the controller (40), and is used to output a low-level signal when the integration circuit outputs a low-level signal; The controller (40) is further used to shut down the normal driving logic of the motor to achieve overcurrent protection for the IPM to be protected when the transistor driving circuit outputs a low-level signal.

6. The device according to claim 4, characterized in that The integration circuit comprises: a first resistor, a second resistor, a third operational amplifier and a capacitor; wherein, The first resistor is arranged between the output end of the current sampling circuit (10) and the inverting input end of the third operational amplifier; The second resistor is arranged at the non-inverting input terminal of the third operational amplifier; The capacitor is arranged between the output terminal of the third operational amplifier and the inverting input terminal of the third operational amplifier.

7. The device according to claim 5, characterized in that The integration circuit comprises: a first resistor, a second resistor, a third operational amplifier and a capacitor; wherein, The first resistor is arranged between the output end of the current sampling circuit (10) and the inverting input end of the third operational amplifier; The second resistor is arranged at the non-inverting input terminal of the third operational amplifier; The capacitor is arranged between the output terminal of the third operational amplifier and the inverting input terminal of the third operational amplifier.

8. The device according to claim 4, characterized in that The transistor driving circuit comprises: a current limiting resistor, a transistor and a second pull-down resistor; wherein, The current limiting resistor is arranged between the output end of the integration circuit and the base of the transistor; the transistor comprises: a PNP transistor; The second pull-down resistor is arranged at the emitter of the triode; the emitter of the triode is connected to the second sampling port of the controller (40); the collector of the triode is connected to a set direct current power supply.

9. The device according to any one of claims 5 to 7, characterized in that: The transistor driving circuit comprises: a current limiting resistor, a transistor and a second pull-down resistor; wherein, The current limiting resistor is arranged between the output end of the integration circuit and the base of the transistor; the transistor comprises: a PNP transistor; The second pull-down resistor is arranged at the emitter of the triode; the emitter of the triode is connected to the second sampling port of the controller (40); the collector of the triode is connected to a set direct current power supply.

10. A motor, characterized in that: include: An IPM protection device as described in any one of claims 1 to 9.

11. An IPM protection method for a motor as claimed in claim 10, characterized in that: include: The three-phase current of the motor driven by the IPM to be protected is collected through a current sampling circuit (10), and a first output signal is output when the motor is normal, or a second output signal is output when the motor is abnormal; Implementing overcurrent protection for the IPM to be protected according to the first output signal through a first overcurrent protection circuit (20); Implementing overcurrent protection for the IPM to be protected according to the second output signal through a second overcurrent protection circuit (30); Also includes: Before the motor driven by the IPM to be protected is turned on, determining whether the IPM current sampling signal of the current sampling circuit (10) is normal; as well as, If the IPM current sampling signal is normal, the normal driving logic of the motor is started to control the normal operation of the motor, and when the first output signal is overcurrent, the first overcurrent protection circuit (20) is used to implement overcurrent protection for the IPM to be protected; If the IPM current sampling signal is abnormal, the normal driving logic of the motor is turned off to implement overcurrent protection for the IPM to be protected through the second overcurrent protection circuit (30).

12. The method according to claim 11, characterized in that The three-phase current of the motor driven by the IPM to be protected is collected through the current sampling circuit (10), including: The first operational amplifier outputs a high level signal when the difference between the first output signal received at its non-inverting input terminal and the first reference signal provided at its inverting terminal is greater than a first set value, and outputs a low level signal otherwise.

13. The method according to any one of claims 11-12, characterized in that: Implementing overcurrent protection for the IPM to be protected according to the first output signal through the first overcurrent protection circuit (20) includes: Through the second operational amplifier, when the first output signal collected at its in-phase input terminal is greater than the second reference signal provided at its inverting input terminal, the first overcurrent protection signal is flipped, and the first overcurrent protection signal that changes from a low-level signal to a high-level signal is output to the overcurrent protection terminal of the IPM to be protected; According to the first over-current protection signal that changes from a low-level signal to a high-level signal, the normal driving logic of the motor is turned off to implement over-current protection for the IPM to be protected.

14. The method according to any one of claims 11-12, characterized in that: Implementing overcurrent protection for the IPM to be protected according to the second output signal through the second overcurrent protection circuit (30) includes: Through the integration circuit, when the second output signal output by the current sampling circuit (10) is a low-level signal, the integrated low-level signal is output; otherwise, the integrated high-level signal is output; Outputting a low-level signal through a transistor driving circuit when the integration circuit outputs a low-level signal; When the transistor drive circuit outputs a low level signal, the normal drive logic of the motor is turned off to implement overcurrent protection for the IPM to be protected.

15. The method according to claim 13, characterized in that Implementing overcurrent protection for the IPM to be protected according to the second output signal through the second overcurrent protection circuit (30) includes: Through the integration circuit, when the second output signal output by the current sampling circuit (10) is a low-level signal, the integrated low-level signal is output; otherwise, the integrated high-level signal is output; Outputting a low-level signal through a transistor driving circuit when the integration circuit outputs a low-level signal; When the transistor drive circuit outputs a low level signal, the normal drive logic of the motor is turned off to implement overcurrent protection for the IPM to be protected.

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