Open-phase fault detection method, control processing unit and motor driving circuit

Abstract

The invention discloses an open-phase fault detection method, a control processing unit and a motor driving circuit. The open-phase fault detection method comprises the following steps: acquiring three-phase current of a three-phase motor; any phase of current in the three-phase current is determined as target current; and in one current period, according to the duration that the current value of the target current is located between the current values of the other two phases of current, determining whether the three-phase motor is open-phase or not. In this way, the open-phase fault can be accurately detected, and the cost is low.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of phase loss detection, and in particular to a phase loss fault detection method, a control processing unit, and a motor drive circuit. Background Art

[0002] A phase loss fault occurs when the voltage on one or more phases of a three-phase power supply system is lost or interrupted, preventing loads (such as motors, inverters, and servo drives) from receiving a complete, balanced three-phase power supply, thus affecting their normal operation. This fault typically occurs at the power input, within the device's internal circuitry, or at the motor connection point. Specifically, the voltage on one or two phases (in extreme cases) cannot be effectively transmitted to the load, disrupting the symmetry of the three-phase power supply system.

[0003] Currently, the method for phase loss fault detection is: collect the three-phase current of the three-phase motor, take the absolute value of the three-phase current and compare it with the preset current threshold after filtering. If the absolute value of any current value is less than the current threshold, it is considered that the current value is too small and a phase loss fault is determined.

[0004] However, the above method is prone to misjudgment on the one hand. For example, if the current is disturbed and fluctuates during current collection, misjudgment may occur. On the other hand, additional hardware filtering is required, which is costly. Summary of the Invention

[0005] The embodiments of the present application provide a phase loss fault detection method, a control processing unit, and a motor drive circuit, which can accurately detect phase loss faults at a low cost.

[0006] In a first aspect, an embodiment of the present application provides a method for detecting a phase loss fault, comprising: obtaining the three-phase current of a three-phase motor; determining any one phase current of the three-phase current as a target current; and determining whether the three-phase motor is phase-lost based on the duration for which the current value of the target current is between the current values of the other two phase currents in a current cycle.

[0007] In one or more embodiments, in one current cycle, whether the three-phase motor is missing a phase is determined based on the duration during which the current value of the target current is between the current values of the other two phase currents, including: if the duration is within a first preset range, determining that the three-phase motor is not missing a phase; if the duration is greater than the first preset value, determining that the three-phase motor is missing a phase.

[0008] In one or more embodiments, in one current cycle, determining whether the three-phase motor is missing a phase is based on the duration for which the current value of the target current is between the current values of the other two phase currents, and also includes: if the duration is less than a second preset value, returning to the step of determining that any phase current of the three-phase current is the target current and its subsequent steps.

[0009] In one or more embodiments, the first preset range is [TS*5 / 36, TS*7 / 36], where TS is the current period.

[0010] In one or more embodiments, the three-phase motor is connected to a motor drive circuit, the motor drive circuit includes a rectifier bridge, a three-phase bridge inverter circuit and a sampling resistor, and the sampling resistor is connected between the rectifier bridge and the three-phase bridge inverter circuit; obtaining the three-phase current of the three-phase motor includes: obtaining the sampling current flowing through the sampling resistor; and performing current reconstruction on the sampling current to obtain the real-time value of the three-phase current.

[0011] In a second aspect, an embodiment of the present application provides a control processing unit, comprising: at least one processor and a memory; the memory is coupled to the processor, and the memory is used to store instructions or programs, and when the instructions or programs are executed by the at least one processor, the at least one processor executes the phase loss fault detection method as described above.

[0012] In a third aspect, an embodiment of the present application provides a motor drive circuit, comprising: a three-phase bridge inverter circuit and the control processing unit as described above, wherein the three-phase bridge inverter circuit is connected to a three-phase motor, and the control processing unit is connected to the three-phase bridge inverter circuit, and the control processing unit is used to control the switching tube in the three-phase bridge inverter circuit to be turned on and / or off to generate a three-phase current, wherein the three-phase current is input to the three-phase motor to drive the three-phase motor to operate.

[0013] In one or more embodiments, the motor drive circuit further includes a rectifier bridge, a bus capacitor and a sampling resistor; the first end of the rectifier bridge is connected to the first end of the input power supply, the second end of the rectifier bridge is connected to the second end of the input power supply, the third end of the rectifier bridge is respectively connected to the first end of the bus capacitor and the three-phase bridge inverter circuit, the fourth end of the rectifier bridge is respectively connected to the second end of the bus capacitor and the first end of the sampling resistor, and the second end of the sampling resistor is connected to the three-phase bridge inverter circuit.

[0014] In one or more embodiments, the three-phase bridge inverter circuit includes three bridge arms in parallel, each bridge arm is connected between the positive and negative poles of the DC bus, and the node of each bridge arm is connected to a phase winding of the three-phase motor; each bridge arm includes two switching tubes in series, and the connection point between the two switching tubes is the node of the corresponding bridge arm.

[0015] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program. When the computer program is executed, the phase loss fault detection method as described above is implemented.

[0016] The beneficial effects of the present application are as follows: the phase loss fault detection method of the embodiment of the present application obtains the three-phase current of the three-phase motor and determines any phase current of the three-phase current as the target current. Then, in one current cycle, whether the three-phase motor is phase-loss is determined according to the duration of time that the current value of the target current is between the current values of the other two phase currents, thereby realizing the phase loss fault detection process. Moreover, since the judgment is based on the duration, the abnormal situation of fluctuation caused by interference when collecting current can be discarded based on not meeting the duration, so there will be no misjudgment and the accuracy is high. In addition, there is no need to add additional hardware filtering as in the related technology, and the cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] One or more embodiments are exemplarily described by the figures in the accompanying drawings, which are not intended to limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements.

[0018] Figure 1 1 is a schematic diagram of the circuit structure of the motor drive circuit provided in an embodiment of the present application;

[0019] Figure 2 Schematic diagram of the circuit structure of the control processing unit provided in an embodiment of the present application;

[0020] Figure 3 This is a flow chart of a phase loss fault detection method provided by an embodiment of the present application;

[0021] Figure 4 This embodiment of the present application provides Figure 3 A schematic diagram of an embodiment of step 310 is shown in FIG.

[0022] Figure 5 This is a schematic diagram of the three-phase current provided in the embodiment of the present application. Figure 1 ;

[0023] Figure 6 This is a schematic diagram of the three-phase current provided in the embodiment of the present application. Figure 2 ;

[0024] Figure 7 This embodiment of the present application provides Figure 3 A schematic diagram of an embodiment of step 330 is shown in FIG.

[0025] Figure 8 This embodiment of the present application provides Figure 3 A schematic diagram of another embodiment of step 330 is shown in FIG.

[0026] Figure 9 This is a schematic diagram of the three-phase current provided in the embodiment of the present application. Figure 3 . DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of them. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0028] It should be noted that, when an element is referred to as being “connected to” another element, it may be directly connected to the other element, or one or more intervening elements may exist therebetween.

[0029] In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as there is no structural conflict between them.

[0030] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the circuit structure of the motor drive circuit provided in the embodiment of the present application. Figure 1 As shown, the motor driving circuit 100 includes a three-phase bridge inverter circuit 10 and a control processing unit 20 .

[0031] The three-phase bridge inverter circuit 10 is connected to the three-phase motor M1. The three-phase bridge inverter circuit 10 includes three bridge arms connected in parallel, namely a first bridge arm 11, a second bridge arm 12, and a third bridge arm 13. Each bridge arm is connected between the positive and negative poles of the DC bus, wherein the upper end of the bus capacitor C1 is the positive pole of the DC bus and the lower end is the negative pole of the DC bus. The node of each bridge arm is connected to a phase winding of the three-phase motor M1, that is, the node P1 of the first bridge arm 11 is connected to a phase winding of the three-phase motor M1; the node P2 of the second bridge arm 12 is connected to a phase winding of the three-phase motor M1; and the node P3 of the third bridge arm 13 is connected to a phase winding of the three-phase motor M1. Each bridge arm includes two switching tubes connected in series, and the connection point between the two switching tubes is the node of the corresponding bridge arm, that is, the first bridge arm 11 includes a first switching tube Q1 and a second switching tube Q2 connected in series, and the connection point between the first switching tube Q1 and the second switching tube Q2 is the node P1 of the first bridge arm 11; the second bridge arm 12 includes a third switching tube Q3 and a fourth switching tube Q4 connected in series, and the connection point between the third switching tube Q3 and the fourth switching tube Q4 is the node P2 of the second bridge arm 12; the third bridge arm 13 includes a fifth switching tube Q5 and a sixth switching tube Q6 connected in series, and the connection point between the fifth switching tube Q5 and the sixth switching tube Q6 is the node P3 of the third bridge arm 13.

[0032] The control processing unit 20 can be a microcontroller unit (MCU) or a digital signal processing (DSP) controller. The control processing unit 20 is connected to each switch tube in the three-phase bridge inverter circuit 10. The control processing unit 20 is used to control the switching tubes in the three-phase bridge inverter circuit 10 to turn on and / or turn off (that is, the control processing unit 20 can be used only to control the switching tubes in the three-phase bridge inverter circuit 10 to turn on, or only to control the switching tubes in the three-phase bridge inverter circuit 10 to turn off, or to control both the switching tubes in the three-phase bridge inverter circuit 10 to turn on and turn off), so as to generate a three-phase current, wherein the three-phase current is input to the three-phase motor to drive the three-phase motor to operate. In some embodiments, the control processing unit 20 uses pulse width modulation (PWM) technology to control the on / off switching of the switches in the three-phase bridge inverter circuit 10 to control the amplitude and frequency of the output voltage of the three-phase bridge inverter circuit 10. By changing the duty cycle of the PWM signal, the effective value of the output voltage can be adjusted; and by changing the frequency of the PWM signal, the frequency of the output AC power can be adjusted. In some embodiments, the control processing unit 20 uses speed sensorless vector control (FOC) technology and space vector PWM (SVPWM) technology to control the three-phase bridge inverter circuit 10 to precisely control the three-phase motor M1 and significantly improve its operating efficiency and speed regulation performance. Among them, FOC technology aims to achieve independent control of motor torque and flux by controlling the space vector of the motor stator current. Its goal is to simplify the complex mathematical model of the AC motor into the model of the DC motor, so that the torque and flux can be directly controlled like a DC motor; SVPWM technology is an optimized PWM technology, which is used to generate a near-ideal sinusoidal waveform output voltage. The specific implementation of FOC technology and SVPWM technology is common knowledge among technicians in this field and will not be repeated here.

[0033] In some embodiments, the motor driving circuit 100 further includes a rectifier bridge 30 , a bus capacitor C1 , and a sampling resistor RT.

[0034] Among them, the first end of the rectifier bridge 30 is connected to the first end of the input power supply 200, the second end of the rectifier bridge 30 is connected to the second end of the input power supply 200, the third end of the rectifier bridge 30 is respectively connected to the first end of the bus capacitor C1 and the three-phase bridge inverter circuit 10, the fourth end of the rectifier bridge 30 is respectively connected to the second end of the bus capacitor C1 and the first end of the sampling resistor RT, and the second end of the sampling resistor RT is connected to the three-phase bridge inverter circuit 10.

[0035] The rectifier bridge 30 includes a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The anode of the first diode D1 and the cathode of the second diode D2 are respectively connected to the first end of the input power supply 200. The cathode of the first diode D1 is respectively connected to the cathode of the third diode D3, the first end of the bus capacitor C1, and the three-phase bridge inverter circuit 10. The anode of the third diode D3 is respectively connected to the cathode of the fourth diode D4 and the second end of the input power supply 200. The anode of the second diode D2 is respectively connected to the anode of the fourth diode D4, the second end of the bus capacitor C1, and the first end of the sampling resistor RT.

[0036] It is understood that in this embodiment, the sampling resistor RT is provided between the second end of the bus capacitor C1 and the three-phase bridge inverter circuit 10 as an example. In other embodiments, the sampling resistor RT may also be provided between the first end of the bus capacitor C1 and the three-phase bridge inverter circuit 10.

[0037] Please refer to Figure 2 The control processing unit 20 includes at least one processor 21 and a memory 22, wherein the memory 22 can be built into the control processing unit 20 or externally located outside the control processing unit 20. The memory 22 can also be a remotely set memory connected to the control processing unit 20 via a network.

[0038] The memory 22 is a non-volatile computer-readable storage medium that can be used to store non-volatile software programs, non-volatile computer executable programs, and modules. The memory 22 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal, etc. In addition, the memory 22 may include a high-speed random access memory and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 22 may optionally include a memory remotely located relative to the processor 21, and these remote memories may be connected to the terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0039] The processor 21 performs various functions of the terminal and processes data by running or executing software programs and / or modules stored in the memory 22, and calling data stored in the memory 22, thereby monitoring the terminal as a whole, for example, implementing the phase failure fault detection method described in any embodiment of the present application.

[0040] The processor 21 may be one or more, Figure 2In the figure, a processor 21 is used as an example. The processor 21 and the memory 22 may be connected via a bus or other means. The processor 21 may include a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a controller, a field-programmable gate array (FPGA) device, etc. The processor 21 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

[0041] Please refer to Figure 3 , Figure 3 This is a flow chart of the phase failure detection method provided in the embodiment of the present application. Figure 3 As shown, the phase loss fault detection method includes the following steps S310 to S330.

[0042] Step S310: Obtain the three-phase current of the three-phase motor.

[0043] Obtaining the three-phase current of a three-phase motor means measuring and determining the current magnitude and phase in each phase input line connected to the three-phase motor. Figure 1 In the diagram, the three-phase current refers to the current between the nodes of each bridge arm and the windings of the three-phase motor.

[0044] In some embodiments, when using Figure 1 When the motor drive circuit 100 is shown, Figure 4 As shown, the specific implementation process of step S310 includes the following steps S410 to S420.

[0045] Step S410: obtaining a sampling current flowing through the sampling resistor.

[0046] Step S420: reconstructing the sampled current to obtain real-time values of the three-phase current.

[0047] In some embodiments, when using Figure 1 In the motor driving circuit 100 shown in FIG. 1 , step S410 is implemented by indirectly calculating the sampling current by measuring the voltage drop across the sampling resistor RT.

[0048] In a three-phase system, the sum of the three-phase currents is theoretically zero, and this property can be used to reconstruct missing phase current information. In this embodiment, since only one sampling resistor RT is used, the current of each phase must be inferred based on the state of the PWM signal and the action of the switch tube. Specifically, which phase is conducting is determined based on the current PWM state. The concept of space vector is used, combined with the changes in the sampled current within the PWM cycle, to estimate the current of each phase. In particular, for a three-phase bridge inverter circuit controlled by SVPWM, the three-phase current can be accurately reconstructed by analyzing the action time and direction of the voltage vector. This embodiment uses only one sampling resistor RT to obtain the real-time value of the three-phase current, without the need for more expensive current detection devices such as current sensors, nor does it require additional filtering design, which helps to reduce costs.

[0049] Step S320: Determine any phase current among the three-phase currents as the target current.

[0050] Step S330 : In one current cycle, determine whether the three-phase motor is missing a phase according to the duration that the current value of the target current is between the current values of the other two phase currents.

[0051] Please refer to Figure 5 , Figure 5 The three-phase currents of the three-phase motor when there is no phase loss are shown as an example. The three-phase currents are the first phase current I1, the second phase current I2 and the third phase current I3, and the current period is TS.

[0052] Take the third-phase current I3 as the target current as an example. Between time T1 and time T2, the current value of the third-phase current I3 is between the current values of the first-phase current I1 and the second-phase current I2, the continuous angle is 60°, and the corresponding duration is TS*60 / 360=TS*1 / 6. Between time T3 and time T4, the current value of the third-phase current I3 is between the current values of the first-phase current I1 and the second-phase current I2, the continuous angle is 60°, and the corresponding duration is TS*1 / 6. It can be seen that under normal circumstances (i.e., when the three-phase motor is not missing a phase), in a current cycle TS, when the current value of the third-phase current I3 is between the current values of the first-phase current I1 and the second-phase current I2, there are two continuous durations, and both of these continuous durations are TS*1 / 6.

[0053] Please refer to Figure 6 , Figure 6 The three-phase currents of a three-phase motor when a phase is missing are shown as an example. This embodiment takes the missing third-phase current I3 as an example. The three-phase currents are the first phase current I1, the second phase current I2 and the third phase current I3, and the current period is TS.

[0054] like Figure 6As shown, the third phase current I3 always remains between the current values of the first phase current I1 and the second phase current I2 , with a duration of 360° and a corresponding duration of TS.

[0055] comprehensive Figure 5 and Figure 6 From the three-phase current shown, it can be obtained that for the two situations of the three-phase motor not being missing a phase and the three-phase current being missing a phase, the duration of time that the current value of the target current is between the current values of the other two phases is different. In this way, based on the duration of time that the current value of the target current is between the current values of the other two phases, it is possible to accurately determine whether the three-phase motor is missing a phase, thereby realizing the process of phase-missing fault detection. Secondly, since the judgment is based on the duration, the abnormal situation of fluctuations caused by interference when collecting current can be discarded based on the fact that the duration is not met, so there will be no misjudgment, and the accuracy is higher. In addition, there is no need to add additional hardware filtering as in the related art, and the cost is low.

[0056] In some embodiments, as Figure 7 As shown, the specific implementation process of step S330 includes the following steps S710 to S720.

[0057] Step S710: If the duration is within the first preset range, it is determined that the three-phase motor is not missing a phase.

[0058] Among them, the first preset range is a pre-set range, which can be set based on the actual application scenario, and the embodiments of the present application do not impose specific restrictions on this. In some embodiments, the first preset range is set according to the duration corresponding to 60° in a current cycle. For example, in a specific embodiment, the first preset range is set according to the duration corresponding to 60°±10° in a current cycle. In this case, the first preset range is: [TS*5 / 36, TS*7 / 36], where TS is the current cycle. Thus, it can effectively avoid misjudgments caused by instantaneous fluctuations due to interference and other reasons, which is conducive to improving the accuracy and reliability of judgments.

[0059] by Figure 5 For example, no matter which phase current among the first phase current I1, the second phase current I2 and the third phase current I3 is used as the target current, the duration for which the current value of the target current is between the current values of the other two phase currents remains at the duration corresponding to 60°, that is, TS*1 / 6, which is within the first preset range [TS*5 / 36, TS*7 / 36], and it is determined that the three-phase motor is not missing a phase at this time.

[0060] Step S720: If the duration is longer than the first preset value, it is determined that the three-phase motor is missing a phase.

[0061] The first preset value is a pre-set value that can be set based on actual application scenarios and is not specifically limited in the present embodiment. In some embodiments, the first preset value is set to a maximum value within a first preset range. Thus, as long as the duration is greater than the maximum value within the first preset range, a phase loss in the three-phase motor can be determined.

[0062] by Figure 6 For example, if the first preset value is the maximum value within the first preset range, and the first preset range is [TS*5 / 36, TS*7 / 36], then if the first phase current I1 or the second phase current I2 is used as the target current, the duration is zero, neither within the first preset range nor greater than the first preset value, and no determination is made. If the third phase current I3 is used as the target current, the duration is TS, which is greater than the first preset value, indicating that the three-phase motor is missing a phase, and the missing phase can be determined to be the phase corresponding to the third phase current I3.

[0063] In some embodiments, as Figure 7 As shown, the specific implementation process of step S330 includes the following step S810.

[0064] Step S810: If the duration is less than the second preset value, return to the step of determining any phase current among the three-phase currents as the target current and subsequent steps.

[0065] The second preset value is a pre-set value that can be set based on actual application scenarios and is not specifically limited in the embodiments of the present application. The second preset value is less than the first preset value. In some implementations, the second preset value is set to the minimum value within the first preset range. This allows abnormal fluctuations caused by interference during current collection to be discarded based on the duration not being met, thereby avoiding misjudgment and achieving higher accuracy.

[0066] For example, in a specific embodiment, Figure 9 As shown, interference occurs during current collection, causing an abnormal fluctuation in the third-phase current I3, resulting in the duration of the third-phase current I3 between time T1 and time T2 being less than the minimum value of the first preset range. In this case, no judgment is made on the detection result, that is, neither the three-phase motor is judged to be phase-lost nor the motor is judged to be phase-free. Then, the step of determining any phase current of the three-phase current as the target current and its subsequent steps are re-executed to continue to judge whether the three-phase motor is phase-lost. It can be seen that the abnormal situation is discarded based on the failure to meet the duration, thereby reducing the risk of misjudgment and improving accuracy.

[0067] The present application also provides a non-volatile computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, which are executed by one or more processors, for example, to execute the above-described Figure 3 、 Figure 4 、 Figure 7 and Figure 8 method steps.

[0068] The present application also provides a computer program product, including a computer program stored on a non-volatile computer-readable storage medium, wherein the computer program includes program instructions. When the program instructions are executed by a computer, the computer executes the phase failure detection method in any of the above method embodiments, for example, the above described Figure 3 、 Figure 4 、 Figure 7 and Figure 8 method steps.

[0069] The above description is merely an embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

[0070] The above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, and the steps may be implemented in any order. A person skilled in the art should understand that the technical solutions described in the above embodiments may be modified, or some of the technical features may be replaced by equivalents. However, such modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for detecting a phase loss fault, characterized in that: include: Get the three-phase current of the three-phase motor; Determining any phase current among the three-phase currents as a target current; In a current cycle, whether the three-phase motor has a phase loss is determined according to a duration during which the current value of the target current is between the current values of the other two phase currents.

2. The method according to claim 1, characterized in that The method of determining whether the three-phase motor has a phase loss according to a duration during which the current value of the target current is between the current values of the other two phase currents in a current cycle includes: If the duration is within a first preset range, it is determined that the three-phase motor has no phase loss; If the duration is greater than a first preset value, it is determined that the three-phase motor is missing a phase.

3. The method according to claim 2, characterized in that The step of determining whether the three-phase motor has a phase loss according to a duration during which the current value of the target current is between the current values of the other two phase currents in a current cycle further includes: If the duration is less than the second preset value, the process returns to the step of determining any one phase current among the three-phase currents as the target current and subsequent steps.

4. The method according to claim 2 or 3, characterized in that The first preset range is [TS*5 / 36, TS*7 / 36], where TS is the current period.

5. The method according to claim 1, wherein The three-phase motor is connected to a motor drive circuit, which includes a rectifier bridge, a three-phase bridge inverter circuit and a sampling resistor, and the sampling resistor is connected between the rectifier bridge and the three-phase bridge inverter circuit; The obtaining of the three-phase current of the three-phase motor includes: Obtaining a sampling current flowing through the sampling resistor; Current reconstruction is performed on the sampled current to obtain real-time values of the three-phase current.

6. A control processing unit, characterized in that: include: at least one processor and memory; The memory is coupled to the processor, and is used to store instructions or programs. When the instructions or programs are executed by the at least one processor, the at least one processor executes the phase loss fault detection method according to any one of claims 1 to 5.

7. A motor drive circuit, characterized in that: include: A three-phase bridge inverter circuit and a control processing unit as claimed in claim 6, wherein the three-phase bridge inverter circuit is connected to a three-phase motor, and the control processing unit is connected to the three-phase bridge inverter circuit, and the control processing unit is used to control the switching tube in the three-phase bridge inverter circuit to be turned on and / or turned off to generate a three-phase current, wherein the three-phase current is input to the three-phase motor to drive the three-phase motor to operate.

8. The motor drive circuit according to claim 7, characterized in that: The motor drive circuit also includes a rectifier bridge, a bus capacitor and a sampling resistor; The first end of the rectifier bridge is connected to the first end of the input power supply, the second end of the rectifier bridge is connected to the second end of the input power supply, the third end of the rectifier bridge is respectively connected to the first end of the bus capacitor and the three-phase bridge inverter circuit, the fourth end of the rectifier bridge is respectively connected to the second end of the bus capacitor and the first end of the sampling resistor, and the second end of the sampling resistor is connected to the three-phase bridge inverter circuit.

9. The motor drive circuit according to claim 7 or 8, characterized in that: The three-phase bridge inverter circuit includes three bridge arms connected in parallel, each bridge arm is connected between the positive and negative poles of the DC bus, and the node of each bridge arm is connected to a phase winding of the three-phase motor; Each bridge arm includes two switching tubes connected in series, and the connection point between the two switching tubes is the node of the corresponding bridge arm.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed, the method for detecting a phase loss fault according to any one of claims 1 to 5 is implemented.

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