Abnormality detection method and device, electric equipment and air conditioning unit

Abstract

The invention discloses an anomaly detection method and device, electric equipment and an air conditioning unit. The method is applied to the IPM module, and comprises the following steps of: after the electric equipment enters a power-on standby stage, controlling upper and lower bridge arms of each phase of the IPM module to be switched off, and judging whether the lower bridge arms of each phase of the IPM module are short-circuited or not according to current of each phase; after the electric equipment enters the bootstrap stage, detecting whether an upper bridge arm of each phase of the IPM module is short-circuited or whether a lower bridge arm of each phase of the IPM module is open-circuited; and after the electric equipment enters the positioning stage, controlling the upper bridge arm and the lower bridge arm of each phase of the IPM module to be switched on according to a preset duty ratio, and then judging whether the upper bridge arm of the phase is in an open circuit or not according to the forward current of each phase. According to the invention, short circuit and open circuit detection of the upper bridge arm and the lower bridge arm can be realized based on a circuit structure of an existing IPM module, a voltage source and a one-way assembly do not need to be additionally arranged, and the device cost can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic power, in particular to an abnormality detection method and device, an electrical equipment and an air conditioning unit. BACKGROUND

[0002] Variable frequency electrical equipment such as variable frequency air conditioners and variable frequency refrigerators has advantages such as energy saving and quietness, and its core control component is an external driver, which includes an IPM module IPM. If a bridge arm in the IPM module is abnormal, it will cause abnormal starting of the electrical equipment or damage to the power device. Therefore, it is necessary to design a self-checking method for the bridge arm abnormality of the IPM module of the external driver, so as to control the electrical equipment to start running when the IPM module is normal, and ensure that there is no starting abnormality and no damage to the power device in the IPM module.

[0003] The existing self-checking scheme for the bridge arm abnormality of the IPM module needs to additionally increase a voltage source and a one-way component, thereby increasing the cost of the device.

[0004] In view of the problem that the existing self-checking scheme for the bridge arm abnormality of the IPM module needs to additionally increase a voltage source and a one-way component, thereby increasing the cost of the device, no effective solution has been proposed at present. SUMMARY

[0005] The present application provides an abnormality detection method and device, an electrical equipment and an air conditioning unit, to solve the problem that the existing self-checking scheme for the bridge arm abnormality of the IPM module needs to additionally increase a detection circuit, thereby increasing the cost of the device, and the open circuit condition of the bridge arm cannot be detected.

[0006] To solve the above technical problems, the present application provides an abnormality detection method applied to an IPM module, which comprises:

[0007] After the electrical equipment enters a power-on standby phase, the upper and lower bridge arms of each phase of the IPM module are controlled to be turned off, and whether the lower bridge arm of each phase of the IPM module is short-circuited is judged according to the current of each phase.

[0008] After the electrical equipment enters a self-boosting phase, whether the upper bridge arm of each phase of the IPM module is short-circuited or the lower bridge arm is open-circuited is detected. For any phase, the upper bridge arm of the phase is controlled to be turned off, and the duty cycle of the lower bridge arm of the phase is gradually increased. During the gradual increase of the duty cycle of the lower bridge arm, whether the upper bridge arm of the phase is short-circuited or the lower bridge arm is open-circuited is judged according to the duty cycle of the lower bridge arm of the phase and the current of the phase.

[0009] After the electrical equipment enters a positioning phase, the upper and lower bridge arms of each phase of the IPM module are controlled to be turned on according to a preset duty cycle, and then whether the upper bridge arm of the phase is open-circuited is judged according to the forward current of the phase.

[0010] Further, judging whether the lower bridge arm of each phase of the IPM module is short-circuited according to the phase current of each phase, comprising:

[0011] judging whether the phase current of the IPM module is zero;

[0012] if not, determining that the lower bridge arm of the phase is short-circuited;

[0013] if yes, determining that the lower bridge arm of the phase is not short-circuited.

[0014] Further, judging whether the upper bridge arm of the phase is short-circuited or the lower bridge arm of the phase is open-circuited according to the duty cycle of the lower bridge arm of the phase and the phase current of the phase, comprising:

[0015] when the duty cycle of the lower bridge arm of the phase is less than a first preset threshold, judging whether the upper bridge arm of the phase is short-circuited according to the phase current of the phase;

[0016] if the upper bridge arm of the phase is not short-circuited, continuing to control the duty cycle of the lower bridge arm of the phase to gradually increase by a preset step;

[0017] when the duty cycle of the lower bridge arm of the phase is greater than a second preset threshold, judging whether the lower bridge arm of the phase is open-circuited according to the phase current of the phase;

[0018] wherein the second preset threshold is greater than the first preset threshold.

[0019] Further, judging whether the upper bridge arm of the phase is short-circuited according to the phase current of the phase when the duty cycle of the lower bridge arm of the phase is less than the first preset threshold, comprising:

[0020] when the duty cycle of the lower bridge arm of the phase is less than the first preset threshold, judging whether the phase current of the phase is greater than an over-current protection threshold;

[0021] if yes, determining that the upper bridge arm of the phase is short-circuited;

[0022] if not, determining that the upper bridge arm of the phase is not short-circuited.

[0023] Further, judging whether the lower bridge arm of the phase is open-circuited according to the phase current of the phase when the duty cycle of the lower bridge arm of the phase is greater than the second preset threshold, comprising:

[0024] when the duty cycle of the lower bridge arm of the phase is greater than the second preset threshold, judging whether the phase current of the phase is 0;

[0025] if yes, determining that the lower bridge arm of the phase is open-circuited;

[0026] if not, determining that the lower bridge arm of the phase is not open-circuited.

[0027] Further, judging whether the upper bridge arm of the phase is open circuit according to the forward current of the phase, comprising:

[0028] Judging whether the forward current of the phase is greater than a preset threshold value; wherein the preset threshold value = the forward current reference value of the phase * k1;

[0029] If yes, it is determined that the upper bridge arm of the phase is open circuit;

[0030] If no, it is determined that the upper bridge arm of the phase is not open circuit.

[0031] The application further provides an abnormality detection device applied to an IPM module, comprising:

[0032] A first detection module is configured to control the upper and lower bridge arms of each phase of the IPM module to be turned off after the electrical equipment enters a power-on standby stage, and to judge whether the lower bridge arm of each phase of the IPM module is short-circuited according to the current of each phase;

[0033] A second detection module is configured to detect whether the upper bridge arm of each phase of the IPM module is short-circuited or the lower bridge arm is open circuit after the electrical equipment enters a bootstrap stage; wherein for any phase, the upper bridge arm of the phase is controlled to be turned off, and the duty cycle of the lower bridge arm of the phase is gradually increased, and whether the upper bridge arm of the phase is short-circuited or the lower bridge arm is open circuit is judged according to the duty cycle of the lower bridge arm of the phase and the current of the phase during the gradual increase of the duty cycle of the lower bridge arm;

[0034] A third detection module is configured to control the upper and lower bridge arms of each phase of the IPM module to be turned on according to a preset duty cycle after the electrical equipment enters a positioning stage, and then to judge whether the upper bridge arm of the phase is open circuit according to the forward current of the phase.

[0035] The application further provides an electrical equipment comprising a motor and an IPM module, and further comprising the above abnormality detection device.

[0036] Further, the electrical equipment is a compressor or a fan.

[0037] The application further provides an air conditioning unit comprising the above electrical equipment.

[0038] The application further provides a computer readable storage medium having a computer program stored thereon, wherein the program is executed by a processor to implement the above abnormality detection method.

[0039] The application further provides an electronic device comprising:

[0040] One or more processors;

[0041] A storage device is configured to store one or more programs, which, when executed by the one or more processors, cause the one or more processors to implement the above abnormality detection method.

[0042] The application is characterized in that, based on the feature that one end of the bootstrap capacitor of the upper bridge arm is connected to the voltage source and the other end is connected to the input end of the lower bridge arm, when the upper bridge arm and the lower bridge arm of each phase are both off, whether the lower bridge arm of each phase of the IPM module is short-circuited is determined by the current of each phase; when the upper bridge arm of the current phase under test is off and the duty cycle of the lower bridge arm gradually increases, whether the upper bridge arm of the phase is short-circuited or the lower bridge arm of the phase is open-circuited is determined according to the matching of the duty cycle of the lower bridge arm of the phase and the current of the phase; when the duty cycle of the lower bridge arm of the current phase under test is small and a large current is detected, it is determined that the upper bridge arm of the current phase under test is short-circuited; when the duty cycle of the lower bridge arm of the current phase under test is large and no current is detected, it is determined that the lower bridge arm of the current phase under test is open-circuited; when it is determined that the lower bridge arm of any phase is not short-circuited and open-circuited and the upper bridge arm is not short-circuited, but after entering the positioning stage, the current of the current phase under test does not reach or approach the pre-designed forward current reference value, it is determined that the upper bridge arm of the current phase under test is open-circuited. Through the above steps, the short-circuit and open-circuit detection of the upper and lower bridge arms can be realized based on the existing circuit structure of the IPM module, without the need for additional voltage sources and unidirectional components, thereby reducing the cost of devices. In addition, through the abnormality detection method of the application, the IPM module can be self-tested in advance, the abnormality of the motor during startup can be prevented in advance, and the risk of damage to the power switch tube and the motor is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 a structure diagram of the IPM module according to the embodiment of the application;

[0044] Figure 2 a flowchart of the abnormality detection method according to the embodiment of the application;

[0045] Figure 3 a structure diagram of the bootstrap circuit of the upper bridge arm of the existing IPM module;

[0046] Figure 4 a flowchart of the abnormality detection method according to another embodiment of the application;

[0047] Figure 5 a flowchart of the upper bridge arm short-circuit and lower bridge arm open-circuit detection of the U phase according to the embodiment of the application;

[0048] Figure 6 a flowchart of the upper bridge arm short-circuit and lower bridge arm open-circuit detection of the V phase according to the embodiment of the application;

[0049] Figure 7Flow chart for W-phase upper bridge arm short circuit and lower bridge arm open circuit detection according to an embodiment of the present application;

[0050] Figure 8 Structure block diagram of an abnormality detection device according to an embodiment of the present application;

[0051] Figure 9 Hardware structure schematic diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0052] In order to make the objects, technical solutions and advantages of the present application clearer, the following will further describe the present application in detail with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0053] The terms used in the embodiments of the present application are only for the purpose of describing particular embodiments and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise. "Plural" generally includes at least two.

[0054] It should be understood that the term "and / or" used herein only describes an association relationship of associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " herein generally represents an "or" relationship between the front and rear associated objects.

[0055] It should be understood that although the terms first, second, third, etc. may be used in the embodiments of the present application to describe operational amplifiers, these operational amplifiers should not be limited to these terms. These terms are only used to distinguish different operational amplifiers. For example, without departing from the scope of the embodiments of the present application, the first operational amplifier can also be referred to as the second operational amplifier, and similarly, the second operational amplifier can also be referred to as the first operational amplifier.

[0056] Depending on the context, the word "if" as used herein can be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrase "if it is determined" or "if (a stated condition or event) is detected" can be interpreted as "when it is determined" or "in response to determining" or "when (a stated condition or event) is detected" or "in response to detecting (a stated condition or event)".

[0057] It is also important to note that the terms "comprises" and / or "comprising," or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0058] Optional embodiments of the present application will be described in detail below with reference to the attached drawings.

[0059] Embodiment 1

[0060] The electrical equipment has the advantages of energy saving, quietness and the like, and a core control component thereof is an external drive. The external drive includes an IPM module IPM. If a bridge arm in the IPM module is abnormal, the electrical equipment will be abnormally started or a power device will be damaged. Therefore, it is necessary to design a self-checking method for the bridge arm abnormality of the IPM module of the external drive, so as to control the electrical equipment to start and run when the IPM module is not abnormal, and ensure that the electrical equipment is not abnormally started and the power device in the IPM module is not damaged.

[0061] The existing self-checking scheme for the bridge arm abnormality of the IPM module needs to additionally increase a voltage source and a unidirectional component, thereby increasing the cost of devices.

[0062] In view of the problem that the existing self-checking scheme for the bridge arm abnormality of the IPM module needs to additionally increase a voltage source and a unidirectional component, thereby increasing the cost of devices, the embodiment provides an abnormality detection method, which is applied to an IPM module, Figure 1This is a structural diagram of an IPM module according to an embodiment of the present invention, wherein P: positive terminal of the bus, N: negative terminal of the bus, IPM module: intelligent power module, Ru: U-phase sampling resistor, Rv: V-phase sampling resistor, Rw: W-phase sampling resistor, Iu: U-phase sampling current, Iv: V-phase sampling current, Iw: W-phase sampling current, PWM: pulse width modulation control signal, HIC1: upper bridge arm driver chip of U-phase, HIC2: upper bridge arm driver chip of V-phase, HIC3: upper bridge arm driver chip of W-phase, LIC1: lower bridge arm driver chip of U-phase, LIC2: lower bridge arm driver chip of V-phase, LIC3: lower bridge arm driver chip of W-phase Bridge arm driver chip: IGBT1: Upper bridge arm switch of U phase; IGBT2: Upper bridge arm switch of V phase; IGBT3: Upper bridge arm switch of W phase; IGBT4: Lower bridge arm switch of U phase; IGBT5: Lower bridge arm switch of V phase; IGBT6: Lower bridge arm switch of W phase; D1: Unidirectional freewheeling diode of upper bridge arm of U phase; D3: Unidirectional freewheeling diode of upper bridge arm of V phase; D4: Unidirectional freewheeling diode of upper bridge arm of W phase; D5: Unidirectional freewheeling diode of lower bridge arm of U phase; D6: Unidirectional freewheeling diode of lower bridge arm of V phase; IC: Main driver chip, such as... Figure 1 As shown, a first resistor Ru, a second resistor Rv, and a third resistor Rw are connected in series between each lower bridge arm of the IPM module and the negative terminal of the bus, respectively, for current sampling. The obtained U-phase sampled current Iu is output to the first operational amplifier OPA1, the V-phase sampled current Iv is output to the second operational amplifier OPA2, and the W-phase sampled current Iw is output to the third operational amplifier OPA3. After being amplified by the first operational amplifier OPA1, the second operational amplifier OPA2, and the third operational amplifier OPA3, the U-phase sampled current Iu, the V-phase sampled current Iv, and the W-phase sampled current Iw are respectively output to the driver main chip IC. The driver main chip IC sends out 6 PWM drive signals to control the on / off state of the three upper bridge arms IGBT1~IGBT3 and the three lower bridge arms IGBT4~IGBT6 of the IPM module. In the prior art, the driver main chip IC controls the operation of the IPM module by detecting the U-phase sampled current Iu, the V-phase sampled current Iv, and the W-phase sampled current Iw of the motor. Therefore, the resistors and operational amplifiers related to the current detection mentioned above are existing structures, and the three-phase current sampling operation of this scheme can be performed using the existing resistors and operational amplifiers.

[0063] Figure 2 This is a flowchart of an anomaly detection method according to an embodiment of the present invention, such as... Figure 2 As shown, the anomaly detection method includes:

[0064] S101, after the electrical equipment enters the power-on standby phase, the upper and lower bridge arms of each phase of the IPM module are turned off, and whether the lower bridge arm of each phase of the IPM module is short-circuited is judged according to the current of each phase.

[0065] Figure 3 The structure diagram of the bootstrap circuit of the upper bridge arm of the existing IPM module is shown in the figure. Figure 3 As shown, C1 and C2 are bootstrap capacitors of the upper bridge arm IGBT1, C3 and C4 are bootstrap capacitors of the upper bridge arm IGBT2, and C5 and C6 are bootstrap capacitors of the upper bridge arm IGBT3. In the case where the upper and lower bridge arms are turned off, the bootstrap capacitors C1-C6 will not be charged, at this time, the U, V and W three-phase will not detect current. Since one end of the three groups of bootstrap capacitors is connected to the driving voltage VB1-VB3 (15V), and the other end is connected to the U, V and W terminals, after power-on, if one or more lower bridge arms are short-circuited, i.e. should be turned off but not turned off, the corresponding bootstrap capacitor of the lower bridge arm will be automatically charged, generating current, at this time, the corresponding phase will generate bootstrap capacitor charging current. Therefore, in the power-on standby phase where the upper and lower bridge arms are turned off, whether the lower bridge arm is short-circuited can be detected by detecting the phase current. After the lower bridge arm is short-circuited, the detection process is suspended until the above abnormality is restored to normal, and the next step of detection is triggered.

[0066] S102, after the electrical equipment enters the bootstrap phase, whether the upper bridge arm of each phase of the IPM module is short-circuited or the lower bridge arm is open-circuited is detected; wherein, for any phase, the upper bridge arm of the phase is controlled to be turned off, and the duty cycle of the lower bridge arm of the phase is gradually increased, and whether the upper bridge arm of the phase is short-circuited or the lower bridge arm of the phase is open-circuited is judged according to the duty cycle of the lower bridge arm of the phase and the current of the phase in the process of gradually increasing the duty cycle of the lower bridge arm of the phase.

[0067] The bootstrap phase, also known as the charging phase of the bootstrap capacitors in the upper arms of each phase of the IPM module, involves the charging of these capacitors after the device enters the bootstrap phase. This charging controls the upper arm of the currently tested phase to turn off, and also controls the upper and lower arms of all other phases to turn off. The duty cycle of the lower arm of the currently tested phase gradually increases according to a preset step size. When the duty cycle of the lower arm is small, if there is no short circuit in the upper arm, the current in the currently tested phase should be small or undetectable. If a large current is detected, it indicates a short circuit in the upper arm of the currently tested phase. Conversely, when the duty cycle of the lower arm of the currently tested phase is large, if there is no open circuit in the lower arm, current should be detectable. Conversely, if no current is detected, it indicates an open circuit in the lower arm of the currently tested phase. Therefore, the duty cycle of the lower arm and the current of the currently tested phase can be used to determine whether the upper arm of the currently tested phase is short-circuited or whether the lower arm is open-circuited. If any phase's upper arm is short-circuited or any phase's lower arm is open-circuited, the testing process is paused until the above abnormality is restored to normal before triggering the next testing step.

[0068] S103 After the electrical equipment enters the positioning stage, the upper and lower bridge arms of each phase of the control IPM module are turned on according to the preset duty cycle, and then the upper bridge arm of the phase is determined to be open based on the positive current of each phase.

[0069] In the positioning phase, a fixed magnetic field is generated by providing a q-axis current (Iq_force) and keeping the d-axis current (Id) zero, dragging the rotor to the initial position. After the electrical equipment enters the positioning phase, the upper and lower bridge arms of each phase are turned on according to the preset duty cycle. Under normal circumstances, the forward current of each phase should be close to the pre-designed forward current reference value. However, if the current of one or more phases is not close to the forward current reference value, and the aforementioned steps confirm that the lower bridge arm of any phase is not short-circuited or open-circuited, and the upper bridge arm is not short-circuited, then it indicates that the upper bridge arm of that phase is open-circuited.

[0070] The abnormality detection method of the embodiment is based on the feature that one end of the bootstrap capacitor of the upper bridge arm is connected to the voltage source and the other end is connected to the input end of the lower bridge arm. When the upper bridge arm and the lower bridge arm of each phase are both off, whether the lower bridge arm of each phase of the IPM module is short-circuited is determined by the current of each phase. When the upper bridge arm of the current detected phase is off and the duty cycle of the lower bridge arm gradually increases, whether the upper bridge arm of the phase is short-circuited or the lower bridge arm of the phase is open-circuited is determined according to the matching of the duty cycle of the lower bridge arm of the phase and the current of the phase. When the duty cycle of the lower bridge arm of the current detected phase is small and a large current is detected, it is determined that the upper bridge arm of the current detected phase is short-circuited. When the duty cycle of the lower bridge arm of the current detected phase is large and no current is detected, it is determined that the lower bridge arm of the current detected phase is open-circuited. When it is determined that the lower bridge arm of any phase is not short-circuited and open-circuited, and the upper bridge arm is not short-circuited, but after entering the positioning stage, the current of the current detected phase does not reach or approach the pre-designed forward current reference value, it is determined that the upper bridge arm of the current detected phase is open-circuited. Through the above steps, the short-circuit and open-circuit detection of the upper and lower bridge arms can be realized based on the existing circuit structure of the IPM module, without the need for additional voltage source and unidirectional components, which can reduce the cost of devices. In addition, through the abnormality detection method of the present application, the IPM module can be self-tested in advance, the motor start-up abnormality can be prevented in advance, and the risk of damage to the power switch tube and the motor is reduced.

[0071] If the lower bridge arm of the current detected phase is not short-circuited, the control signals of all bridge arms are off signals in the power-on standby stage. Under normal circumstances, the lower bridge arm should be in an open state, and a path cannot be formed between the voltage source, the bootstrap capacitor and the negative bus. Therefore, in order to accurately determine whether the lower bridge arm of each phase is short-circuited, whether the current of each phase of the IPM module is zero is determined. If not, it is determined that the lower bridge arm of the phase is short-circuited. If yes, it is determined that the lower bridge arm of the phase is not short-circuited.

[0072] Under the premise that short circuit does not occur in the lower bridge arm of each phase, after the power utilization device enters the self-boosting phase, if the upper bridge arm of the current phase under test is not short-circuited and the lower bridge arm is not open-circuited, the duty ratio of the lower bridge arm of the phase and the current of the phase should be matched, the current of the phase is small or undetectable when the duty ratio of the lower bridge arm is small, and the self-boosting capacitor charging current of the phase can be detected when the duty ratio of the lower bridge arm is large. Therefore, in order to accurately determine whether the upper bridge arm of each phase of the IPM module is short-circuited or the lower bridge arm is open-circuited, whether the upper bridge arm of the phase is short-circuited or the lower bridge arm is open-circuited is determined according to the duty ratio of the lower bridge arm of the phase and the current of the phase, which comprises: when the duty ratio of the lower bridge arm of the phase is less than a first preset threshold, determining whether the upper bridge arm of the phase is short-circuited according to the current of the phase; if the upper bridge arm of the phase is not short-circuited, continuing to control the duty ratio of the lower bridge arm of the phase to gradually increase by a preset step; when the duty ratio of the lower bridge arm of the phase is greater than a second preset threshold, determining whether the lower bridge arm of the phase is open-circuited according to the current of the phase; wherein the second preset threshold is greater than the first preset threshold. When the duty ratio of the lower bridge arm of the phase is less than the first preset threshold, whether the upper bridge arm of the phase is short-circuited is determined according to the current of the phase, which comprises: when the duty ratio of the lower bridge arm of the phase is less than the first preset threshold, determining whether the current of the phase is greater than an overcurrent protection threshold; if yes, it indicates that the upper and lower bridge arms of the phase are short-circuited, and the upper bridge arm should be in an off state at this time, so it can be determined that the upper bridge arm of the phase is short-circuited; if no, it indicates that the upper bridge arm of the phase is in an off state, and it can be determined that the upper bridge arm of the phase is not short-circuited. When the duty ratio of the lower bridge arm of the phase is greater than the second preset threshold, whether the lower bridge arm of the phase is open-circuited is determined according to the current of the phase, which comprises: when the duty ratio of the lower bridge arm of the phase is greater than the second preset threshold, determining whether the current of the phase is 0; if yes, it can be determined that the lower bridge arm of the phase is open-circuited. The current of 0 indicates that the phase has no current, and under the condition that the duty ratio of the lower bridge arm is the second preset threshold, the self-boosting charging current of the phase should be generated, and if not, it can be determined that the lower bridge arm of the phase is open-circuited; if the current of the phase is not 0, it is determined that the lower bridge arm of the phase is not open-circuited.

[0073] According to the foregoing, after the power utilization device enters the positioning phase, the upper bridge arm and the lower bridge arm of each phase are turned on according to the preset duty ratio, and under normal circumstances, the forward current of each phase should be close to the forward current reference value designed in advance, and if the current of one or more phases is not close to the forward current reference value, and it is determined through the foregoing steps that the lower bridge arm of any phase does not have a short circuit and an open circuit, and the upper bridge arm does not have a short circuit, therefore, it is indicated that the upper bridge arm of the phase has an open circuit, therefore, in order to accurately determine whether the upper bridge arm of each phase has an open circuit, whether the upper bridge arm of the phase has an open circuit is determined according to the forward current of each phase, comprising: determining whether the forward current of each phase is greater than a preset threshold value; wherein the preset threshold value = the forward current reference value of each phase * k1, wherein 0.95 ≤ k1 ≤ 1; if yes, it is determined that the upper bridge arm of the phase has an open circuit; if no, it is determined that the upper bridge arm of the phase does not have an open circuit.

[0074] In summary, as mentioned above Figure 1 As shown in the figure, the drive main chip IC controls the upper bridge arm drive chip HVIC1~HVIC3 and the lower bridge arm drive chip LVIC1~LVIC3 of the IPM module through 6-way PWM signals, and drives the IGBT1~IGBT6 to switch, controls the external motor to rotate according to the three-phase sampling current Iu, Iv, Iw. When HVIC1~HVIC3, LVIC1~LVIC3 and IGBT1~6 are abnormal, the IPM module cannot work normally. When the upper bridge arm of the IPM module is open-circuit abnormal, that is, HVIC1~HVIC3 or IGBT1~IGBT3 is open-circuit abnormal, at this time the external motor cannot be connected to the positive pole of the bus, and cannot generate the forward current from the positive pole of the bus to the negative pole through the motor stator winding; when the upper bridge arm of the IPM module is short-circuit, that is, HVIC1~HVIC3 or IGBT1~IGBT3 is short-circuit abnormal, if the IPM lower bridge arm is turned on at this time, a straight-through phenomenon will be formed between the upper bridge arm and the lower bridge arm, a large current will be generated and a hardware overcurrent phenomenon will occur; when the lower bridge arm of the IPM module is open-circuit abnormal, that is, LVIC1~LVIC3 or IGBT4~IGBT6 is open-circuit abnormal, at this time there is no open-circuit signal in the upper bridge arm, and the forward current cannot be generated in the U, V, W phase; when the lower bridge arm of the IPM module is short-circuit, that is, LVIC1~LVIC3 or IGBT4~IGBT6 is short-circuit abnormal, during the power-on standby, there will be a bootstrap charging current.

[0075] Therefore, the abnormal self-checking process of the IPM module is as follows:

[0076] According to the characteristics of the IPM module bridge arm in various abnormal situations, an abnormal self-checking sequence and method are designed. When the motor drive board is designed, the bootstrap capacitor of the upper bridge arm of the IPM module has a first end connected to the driving voltage 15V and a second end connected to the lower bridge arm of the IPM module. When the motor drive board is powered on, if a short circuit occurs in the lower bridge arm, the bootstrap capacitor will automatically charge and generate a current. Therefore, the first sequence of detection is the short circuit of the lower bridge arm of the UVW phase. After the initialization of the driving main chip is completed, the Ru, Rv, Rw current values are sampled in real time. If there is no IPM module abnormality, the bridge arms of the U phase, V phase and W phase are sequentially self-checked. In the power-on standby state of the electrical equipment, the upper and lower bridge arms of each phase are in the off state. If a current is detected in the currently checked phase, it is judged that a short circuit occurs in the lower bridge arm of the currently checked phase. That is, in the power-on standby state, the upper and lower bridge arms of each phase are turned off. By detecting whether the bootstrap capacitor charging current is generated in each phase, the short circuit abnormality of the lower bridge arm can be detected.

[0077] Under the premise that the lower bridge arms of the IPM module in each phase are not short-circuited, by keeping the upper bridge arm of the currently checked phase and the upper and lower bridge arms of the currently unchecked phase off, the duty cycle of the lower bridge arm of the currently checked phase is gradually increased by a preset step StepInc to determine whether the upper bridge arm of the currently checked phase is short-circuited or the lower bridge arm is open-circuited. When the duty cycle of the lower bridge arm of the currently checked phase is below 20%, if the upper bridge arm of the currently checked phase is not short-circuited, the current of the currently checked phase is very small or undetectable; if the upper bridge arm of the currently checked phase is short-circuited, the upper and lower bridge arms of the currently checked phase will be short-circuited, which will cause an overcurrent to occur rapidly. Therefore, when the duty cycle of the lower bridge arm of the currently checked phase is below 20%, if a large current is detected, it can be determined that the upper bridge arm of the currently checked phase is short-circuited. When the duty cycle of the lower bridge arm of the currently checked phase reaches more than 80%, if no bootstrap capacitor charging current is detected, it can be determined that the lower bridge arm of the currently checked phase is open-circuited. In the bootstrap stage of the unit operation, the driving main chip turns off the upper bridge arm of the currently checked phase and gradually increases the duty cycle of the lower bridge arm of the currently checked phase by a preset step StepInc. If an overcurrent occurs in the currently checked phase when the duty cycle of the lower bridge arm of the currently checked phase is less than 20%, it is judged that the upper bridge arm of the currently checked phase is short-circuited. If no current of the currently checked phase is detected when the duty cycle of the lower bridge arm of the currently checked phase is greater than 80%, it is judged that the lower bridge arm of the currently checked phase is open-circuited. That is, under the condition that the lower bridge arms of each phase are not short-circuited, by turning off the upper bridge arm of the currently checked phase and the upper and lower bridge arms of the remaining phases, the duty cycle of the lower bridge arm of the currently checked phase is continuously increased by a preset step StepInc. Whether the current of the currently checked phase matches the duty cycle of the lower bridge arm of the phase can be determined, which can realize the detection of the short-circuit abnormality of the upper bridge arm and the open-circuit abnormality of the lower bridge arm.

[0078] Under the premise that the lower bridge arms of the UVW three-phase of the IPM module are normal and the upper bridge arms are not short-circuit abnormal, by controlling the lower bridge arms of the UVW to be turned on according to a specific duty ratio and the upper bridge arm of the current detected phase to be turned on according to a target current demand duty ratio, a forward target current is generated to detect whether the upper bridge arm of the current detected phase has an open circuit abnormality; if the motor winding corresponding to the current detected phase cannot generate the forward target current at this time, it can be determined that the upper bridge arm of the current detected phase is open. Therefore, during the unit operation positioning stage, the drive main chip controls the on-off action of the upper and lower bridge arms of the IPM module, and generates the forward current value of each phase on the external motor, and judges whether the actual sampling current value of each phase is greater than 0.95*forward current reference value Iref, if yes, it is determined that the upper bridge arm of the phase is normal, if no, it is determined that the upper bridge arm of the phase is open. That is, under the condition that the lower bridge arms of each phase of the IPM module do not have short circuit and open circuit, and the upper bridge arm of each phase does not have short circuit, by whether the forward current is generated in the winding direction of the current detected phase, the upper bridge arm open circuit abnormality can be detected.

[0079] The abnormality detection method of the embodiment can detect the abnormality of the upper and lower bridge arms of each phase of the IPM module through the existing circuit structure without increasing additional voltage source and one-way components, can realize low-cost abnormality detection, and can reduce the possibility of damage to the power switch tube and the motor body during motor start-up and operation.

[0080] Embodiment 2

[0081] The embodiment provides another abnormality detection method, Figure 4 The flowchart of the abnormality detection method according to another embodiment of the application is shown in Figure 4 The method comprises:

[0082] S41, power-on initialization.

[0083] S42, control the upper and lower bridge arms of each phase to be turned off, and then detect the U-phase current iu, the V-phase current iv and the W-phase current iw.

[0084] S43, judge whether each phase has a lower bridge arm short circuit abnormality in turn; if yes, return to step S42; if no, execute step S44.

[0085] In the design of the motor drive board, the bootstrap capacitor of the upper bridge arm of the IPM module is connected to the driving voltage 15V at the first end and to the lower bridge arm of the IPM module at the second end. When the motor drive board is powered on, if a short circuit occurs in the lower bridge arm, the bootstrap capacitor will automatically charge and generate current. Therefore, the short circuit of the lower bridge arm of the UVW phase is the first sequence detection. After the initialization of the driving main chip is completed, real-time sampling of the Ru, Rv, Rw current values is started. If there is no IPM module abnormality, self-checking of the bridge arms of the U phase, V phase and W phase is performed in sequence. In the power-on standby state of the electrical equipment, the upper bridge arm and the lower bridge arm of each phase are in the off state. If it is detected that the current is generated in the currently checked phase, it is judged that a short circuit occurs in the lower bridge arm of the currently checked phase. That is, in the power-on standby state, the upper and lower bridge arms of each phase are turned off. By detecting whether the bootstrap capacitor charging current is generated in each phase, the short circuit abnormality of the lower bridge arm can be detected.

[0086] S44, the upper bridge arm short circuit and lower bridge arm open circuit detection process of the U phase of the IPM module is performed.

[0087] S45, the upper bridge arm short circuit and lower bridge arm open circuit detection process of the V phase of the IPM module is performed.

[0088] S46, the upper bridge arm short circuit and lower bridge arm open circuit detection process of the W phase of the IPM module is performed.

[0089] If the lower bridge arm of the current detected phase is turned on with the duty cycle less than 20%, and the current of the current detected phase is small or not detected, it is determined that the upper bridge arm of the current detected phase is short-circuited; if the current of the current detected phase is too large, it is determined that the upper bridge arm of the current detected phase is short-circuited; if the duty cycle of the lower bridge arm of the current detected phase is greater than 80% and the charging current of the bootstrap capacitor is not detected, it is determined that the lower bridge arm of the current detected phase is open-circuited. In the bootstrap stage of the operation of the unit, the driving main chip turns off the upper bridge arm of the current detected phase, and gradually increases the duty cycle of the lower bridge arm of the current detected phase at a preset step StepInc; if the current detected phase has overcurrent when the duty cycle of the lower bridge arm of the current detected phase is less than 20%, it is determined that the upper bridge arm of the current detected phase is short-circuited; if the current of the current detected phase is not detected when the duty cycle of the lower bridge arm of the current detected phase is greater than 80%, it is determined that the lower bridge arm of the current detected phase is open-circuited. That is, in the case that the lower bridge arms of all phases are not short-circuited, the upper bridge arm of the current detected phase is turned off and the upper and lower bridge arms of the other phases are turned on, and the duty cycle of the lower bridge arm of the current detected phase is gradually increased at a preset step StepInc, so that whether the current of the current detected phase matches the duty cycle of the lower bridge arm of the current detected phase is determined, and the upper bridge arm short-circuit abnormality and the lower bridge arm open-circuit abnormality can be detected.

[0090] S47, the upper and lower bridge arms of each phase are turned on according to the preset duty cycle, and then the U-phase current iu, the V-phase current iv and the W-phase current iw are detected.

[0091] S48, whether the upper bridge arm of each phase has an open-circuit abnormality is determined in sequence; if yes, step S49 is performed; if no, step S42 is returned.

[0092] Under the premise that the lower bridge arms of the UVW three-phase of the IPM module are normal and the upper bridge arms are not short-circuit abnormal, by controlling the lower bridge arms of the UVW to be turned on according to a specific duty ratio and the upper bridge arm of the current detected phase to be turned on according to a target current demand duty ratio, a forward target current is generated to detect whether the upper bridge arm of the current detected phase is open-circuit abnormal; if the motor winding corresponding to the current detected phase cannot generate the forward target current at this time, it can be determined that the upper bridge arm of the current detected phase is open-circuit. Therefore, during the unit operation positioning stage, the drive main chip controls the on-off action of the upper and lower bridge arms of the IPM module, and generates the forward current value of each phase on the external motor, and judges whether the actual sampling current value of each phase is greater than 0.95*forward current reference value Iref; if yes, it is determined that the upper bridge arm of the phase is normal, and if no, it is determined that the upper bridge arm of the phase is open-circuit. That is, under the condition that the lower bridge arms of each phase of the IPM module are not short-circuit and open-circuit, and the upper bridge arm of each phase is not short-circuit, whether the forward current is generated in the winding direction of the current detected phase can realize the detection of the open-circuit abnormality of the upper bridge arm.

[0093] S49, end the detection process.

[0094] Figure 5 For the upper bridge arm short-circuit and lower bridge arm open-circuit detection process of the U phase according to the embodiment of the application, as shown in the flowchart, Figure 5 the detection process specifically includes:

[0095] S441, after the use electric device runs to the bootstrap stage, the upper bridge arm short-circuit and lower bridge arm open-circuit detection process of the U phase is entered.

[0096] S442, the upper bridge arms of each phase of the IPM module are controlled to maintain a non-turn-on state, and the duty ratio of the lower bridge arm of the U phase is controlled to gradually increase according to a preset step length StepInc.

[0097] S443, whether the duty ratio of the lower bridge arm of the U phase is less than 20% is judged; if yes, step S444 is executed; if no, step S446 is executed.

[0098] S444, whether the current of the U phase exceeds the overcurrent protection threshold is judged; if yes, step S445 is executed; if no, step S442 is returned.

[0099] S445, the upper bridge arm short-circuit of the U phase is determined, and then step S449 is executed.

[0100] S446, whether the duty ratio of the lower bridge arm of the U phase is greater than 80% is judged; if yes, step S447 is executed; if no, step S449 is executed.

[0101] S447, whether the U phase current is detected is judged; if yes, step S448 is executed.

[0102] S448, determine whether the lower bridge arm of the U phase is open, and execute step S449.

[0103] S449, end the upper bridge arm short circuit and lower bridge arm open detection process of the U phase.

[0104] Figure 6 For the upper bridge arm short circuit and lower bridge arm open detection process of the V phase according to the embodiment of the application, as shown in FIG. 5, the detection process specifically includes: Figure 6

[0105] S451, after the electrical equipment runs to the bootstrap stage, enter the upper bridge arm short circuit and lower bridge arm open detection process of the V phase.

[0106] S452, control the upper bridge arm of each phase of the IPM module to maintain a non-conducting state, and control the duty cycle of the lower bridge arm of the V phase to gradually increase according to a preset step size StepInc.

[0107] S453, determine whether the duty cycle of the lower bridge arm of the V phase is less than 20%; if yes, execute step S454; if no, execute step S456.

[0108] S454, determine whether the current of the V phase exceeds an overcurrent protection threshold; if yes, execute step S455; if no, return to step S452.

[0109] S455, determine that the upper bridge arm of the V phase is short-circuited, and then execute step S459.

[0110] S456, determine whether the duty cycle of the lower bridge arm of the V phase is greater than 80%; if yes, execute step S457; if no, execute step S459.

[0111] S457, determine whether the current of the V phase is detected; if yes, execute step S458.

[0112] S458, determine that the lower bridge arm of the V phase is open, and execute step S459.

[0113] S459, end the upper bridge arm short circuit and lower bridge arm open detection process of the V phase.

[0114] Figure 7 For the upper bridge arm short circuit and lower bridge arm open detection process of the W phase according to the embodiment of the application, as shown in FIG. 6, the detection process specifically includes: Figure 7

[0115] S461, after the electrical equipment runs to the bootstrap stage, enter the upper bridge arm short circuit and lower bridge arm open detection process of the W phase.

[0116] ​​S462, maintaining the upper bridge arm of each phase of the IPM module in a non-conducting state, and gradually increasing the duty cycle of the lower bridge arm of the W phase according to a preset step size StepInc.

[0117] S463, determining whether the duty cycle of the lower bridge arm of the W phase is less than 20%; if yes, executing step S464; if no, executing step S466.

[0118] S464, determining whether the current of the W phase exceeds an overcurrent protection threshold; if yes, executing step S465; if no, returning to step S462.

[0119] S465, determining that the upper bridge arm of the W phase is short-circuited, and then executing step S469.

[0120] S466, determining whether the duty cycle of the lower bridge arm of the W phase is greater than 80%; if yes, executing step S467; if no, executing step S469.

[0121] S467, determining whether the current of the W phase is detected; if yes, executing step S468.

[0122] S468, determining that the lower bridge arm of the W phase is open-circuited, and executing step S469.

[0123] S469, ending the upper bridge arm short-circuit and lower bridge arm open-circuit detection process of the W phase.

[0124] Embodiment 3

[0125] The embodiment provides an abnormality detection device applied to an IPM module, Figure 8 A structural block diagram of the abnormality detection device according to the embodiment of the present application is shown in Figure 8 The abnormality detection device comprises:

[0126] The first detection module 10 is configured to, after the electrical equipment enters the power standby stage, control the upper and lower bridge arms of each phase of the IPM module to be turned off, and determine whether the lower bridge arm of each phase of the IPM module is short-circuited according to the current of each phase.

[0127] The above problems and Figure 3As shown, C1 and C2 are bootstrap capacitors of the upper bridge arm IGBT1, C3 and C4 are bootstrap capacitors of the upper bridge arm IGBT2, and C5 and C6 are bootstrap capacitors of the upper bridge arm IGBT3. In the case where the upper and lower bridge arms are both off, none of C1-C6 will be charged, and at this time, no current will be detected in the U, V, and W phases. Since one end of each of the three groups of bootstrap capacitors is connected to the driving voltage VB1-VB3 (15V) and the other end is connected to the U, V, and W terminals, if one or more of the lower bridge arms is short-circuited after power-on, i.e., should be off but is not, the bootstrap capacitor corresponding to the lower bridge arm will be automatically charged, generating a current. At this time, the corresponding phase will generate a bootstrap capacitor charging current. Therefore, in the power-on standby phase where the upper and lower bridge arms are both off, whether the lower bridge arm is short-circuited can be detected by detecting the phase current. After the lower bridge arm is short-circuited, the detection process is paused until the above abnormality returns to normal, triggering the next detection.

[0128] The second detection module 20 is configured to detect whether the upper bridge arm of each phase of the IPM module is short-circuited or the lower bridge arm is open-circuited after the use electric device enters the bootstrap phase. For any phase, the upper bridge arm of the phase is controlled to be off, and the duty cycle of the lower bridge arm of the phase is gradually increased. During the gradual increase of the duty cycle of the lower bridge arm of the phase, whether the upper bridge arm of the phase is short-circuited or the lower bridge arm is open-circuited is determined according to the duty cycle of the lower bridge arm of the phase and the current of the phase.

[0129] After the use electric device enters the bootstrap phase, the bootstrap capacitor is charged, the upper bridge arm of the current phase to be detected is controlled to be off, and the upper and lower bridge arms of the remaining phases are controlled to be off. The duty cycle of the lower bridge arm of the current phase to be detected is gradually increased by a preset step. When the duty cycle of the lower bridge arm is small, if the upper bridge arm is not short-circuited, the current of the current phase to be detected should be small or undetectable. At this time, if a large current is detected, it indicates that the upper bridge arm of the current phase to be detected is short-circuited. When the duty cycle of the lower bridge arm of the current phase to be detected is large, if the lower bridge arm of the current phase to be detected is not open-circuited, the current of the phase should be detectable. On the contrary, if the current is not detected, it indicates that the lower bridge arm of the current phase to be detected is open-circuited. Therefore, whether the upper bridge arm of the current phase to be detected is short-circuited or the lower bridge arm is open-circuited can be determined according to the duty cycle of the lower bridge arm of the current phase to be detected and the current of the current phase to be detected. After the upper bridge arm of any phase is short-circuited or the lower bridge arm of any phase is open-circuited, the detection process is paused until the above abnormality returns to normal, triggering the next detection.

[0130] The third detection module 30 is configured to control the upper and lower bridge arms of each phase of the IPM module to be turned on according to a preset duty cycle after the use electric device enters the positioning phase, and then determine whether the upper bridge arm of the phase is open-circuited according to the forward current of the phase.

[0131] After the use electric equipment enters the positioning stage, the upper bridge arm and the lower bridge arm of each phase are turned on according to the preset duty ratio, and under normal circumstances, the forward current of each phase should be close to the forward current reference value designed in advance, and if the current of one or more phases is not close to the forward current reference value, and it is determined through the foregoing steps that the lower bridge arm of any phase does not occur short circuit and open circuit, and the upper bridge arm does not occur short circuit, therefore, it is indicated that the upper bridge arm of the phase occurs open circuit.

[0132] The abnormality detection device of the embodiment, through the first detection module 10 based on the feature that one end of the bootstrap capacitor of the upper bridge arm is connected with the voltage source and the other end is connected with the input end of the lower bridge arm, when the upper bridge arm and the lower bridge arm of each phase are all turned off, whether the lower bridge arm of each phase of the IPM module is short-circuited is judged through the current of each phase; through the second detection module 20 when the duty ratio of the lower bridge arm of the current detected phase is gradually increased while the upper bridge arm of the current detected phase is turned off, whether the upper bridge arm of the phase is short-circuited or the lower bridge arm of the phase is open-circuited is judged according to the matching of the duty ratio of the lower bridge arm of the phase and the current of the phase, when the duty ratio of the lower bridge arm of the current detected phase is small and a large current is detected, it is determined that the upper bridge arm of the current detected phase occurs short circuit; through the third detection module 30, when the duty ratio of the lower bridge arm of the current detected phase is large and no current is detected, it is determined that the lower bridge arm of the current detected phase occurs open circuit; when it is determined that the lower bridge arm of any phase does not occur short circuit and open circuit, and the upper bridge arm does not occur short circuit, but after entering the positioning stage, the current of the current detected phase does not reach or is close to the forward current reference value designed in advance, it is determined that the upper bridge arm of the current detected phase is open-circuited. Through the foregoing steps, short circuit and open circuit detection of the upper and lower bridge arms can be realized based on the existing circuit structure of the IPM module, without additional voltage source and unidirectional components, the cost of devices can be reduced, in addition, through the abnormality detection device of the application, the IPM module can be self-detected in advance, the abnormality of motor start-up operation can be prevented in advance, and the risk of damage of power switch tube and motor is reduced.

[0133] If the lower bridge arm of the current detected phase does not occur short circuit, the control signal of all bridge arms is the turn-off signal in the power-on standby stage, under normal circumstances, the lower bridge arm should be in the open state, and a path cannot be formed between the voltage source, the bootstrap capacitor and the negative bus, and the current of the current detected phase should be 0, therefore, in order to accurately judge whether the lower bridge arm of each phase is short-circuited, the first detection module specifically performs the following operations when judging whether the lower bridge arm of each phase of the IPM module is short-circuited according to the current of each phase: whether the current of each phase of the IPM module is zero is judged; if not, it is determined that the lower bridge arm of the phase is short-circuited; if yes, it is determined that the lower bridge arm of the phase is not short-circuited.

[0134] In the premise that short circuit does not occur in the lower bridge arm of each phase, after the use electric device enters the self-lift stage, if the upper bridge arm of the current detected phase is not short-circuited and the lower bridge arm is not open-circuited, then the duty ratio of the lower bridge arm of the phase and the current of the phase should be matched, the current of the phase is small or undetectable when the duty ratio of the lower bridge arm is small, and the self-lift capacitor charging current of the phase can be detected when the duty ratio of the lower bridge arm is large. Therefore, in order to accurately judge whether the upper bridge arm of each phase of the IPM module is short-circuited or the lower bridge arm is open-circuited, the second detection module 20 specifically performs the following operations when judging whether the upper bridge arm of the phase is short-circuited or the lower bridge arm is open-circuited according to the duty ratio of the lower bridge arm of the phase and the current of the phase: when the duty ratio of the lower bridge arm of the phase is less than a first preset threshold, judging whether the upper bridge arm of the phase is short-circuited according to the current of the phase; if the upper bridge arm of the phase is not short-circuited, continuing to control the duty ratio of the lower bridge arm of the phase to gradually increase according to a preset step; when the duty ratio of the lower bridge arm of the phase is greater than a second preset threshold, judging whether the lower bridge arm of the phase is open-circuited according to the current of the phase; wherein the second preset threshold is greater than the first preset threshold. When the duty ratio of the lower bridge arm of the phase is less than the first preset threshold, judging whether the upper bridge arm of the phase is short-circuited according to the current of the phase, comprising: when the duty ratio of the lower bridge arm of the phase is less than the first preset threshold, judging whether the current of the phase is greater than an overcurrent protection threshold; if yes, it indicates that the upper and lower bridge arms of the phase are short-circuited, and the upper bridge arm should be off at this time, so it can be determined that the upper bridge arm of the phase is short-circuited; if no, it indicates that the upper bridge arm of the phase is off, and it can be determined that the upper bridge arm of the phase is not short-circuited. When the duty ratio of the lower bridge arm of the phase is greater than the second preset threshold, judging whether the lower bridge arm of the phase is open-circuited according to the current of the phase, comprising: when the duty ratio of the lower bridge arm of the phase is greater than the second preset threshold, judging whether the current of the phase is 0; if yes, it can be determined that the lower bridge arm of the phase is open-circuited. The current of 0 indicates that the phase has no current, and under the condition that the duty ratio of the lower bridge arm is the second preset threshold, the self-lift charging current of the phase should be generated, if not, it can be determined that the lower bridge arm of the phase is open-circuited; if the current of the phase is not 0, it is determined that the lower bridge arm of the phase is not open-circuited.

[0135] According to the foregoing, after the power utilization device enters the positioning phase, the upper bridge arm and the lower bridge arm of each phase are turned on according to the preset duty ratio, and under normal circumstances, the forward current of each phase should be close to the forward current reference value designed in advance, and if the current of one or more phases is not close to the forward current reference value, and it is determined through the foregoing steps that the lower bridge arm of any phase does not occur short circuit and open circuit, and the upper bridge arm does not occur short circuit, therefore, it is indicated that the upper bridge arm of the phase occurs open circuit, therefore, in order to accurately determine whether the upper bridge arm of each phase occurs open circuit, when the third detection module 30 determines whether the upper bridge arm of each phase occurs open circuit according to the forward current of each phase, the following operations are specifically performed: it is determined whether the forward current of each phase is greater than a preset threshold value; wherein the preset threshold value = the forward current reference value of each phase * k1, wherein 0.95 <= k1 <= 1; if yes, it is determined that the upper bridge arm of the phase occurs open circuit; if no, it is determined that the upper bridge arm of the phase does not occur open circuit.

[0136] Embodiment 4

[0137] The embodiment provides a power utilization device, which comprises a motor and an IPM module, and further comprises the abnormality detection device in the foregoing embodiments, so that the short circuit and open circuit detection of the upper bridge arm and the lower bridge arm can be performed based on the circuit structure of the existing IPM module, without the need of additionally increasing a voltage source and a unidirectional component, and the device cost can be reduced.

[0138] In some embodiments of the present application, the power utilization device is a compressor or a fan.

[0139] Embodiment 5

[0140] The embodiment provides an air conditioning unit, which comprises the power utilization device in the foregoing embodiments, so that the short circuit and open circuit detection of the upper bridge arm and the lower bridge arm can be performed based on the circuit structure of the existing IPM module, without the need of additionally increasing a voltage source and a unidirectional component, and the device cost can be reduced.

[0141] Embodiment 6

[0142] The embodiment provides a computer readable storage medium, which stores a computer program, and the program is executed by a processor to realize the foregoing abnormality detection method.

[0143] Embodiment 7

[0144] The embodiment provides an electronic device, which comprises:

[0145] one or more processors;

[0146] a storage device configured to store one or more programs, which, when executed by the one or more processors, cause the one or more processors to implement the foregoing abnormality detection method.

[0147] Figure 9A schematic diagram of a hardware structure of an electronic device according to an embodiment of the present application is shown in Figure 9 The electronic device includes:

[0148] one or more processors 910 and a memory 920, Figure 9 The processor 910 is taken as an example.

[0149] The electronic device can further include an input device 930 and an output device 940.

[0150] The processor 910, the memory 920, the input device 930 and the output device 940 can be connected by a bus or other means, Figure 9 The connection by the bus is taken as an example.

[0151] The memory 920 is a non-volatile computer readable storage medium, which can be used to store non-volatile software programs, non-volatile computer executable programs and modules, such as program instructions / modules corresponding to the abnormality detection method in the embodiments of the present application. The processor 910 executes various functional applications and data processing of the server by running the non-volatile software programs, instructions and modules stored in the memory 920, that is, implements the above-mentioned method embodiments.

[0152] The memory 920 can include a program storage area and a data storage area, wherein the program storage area can store application programs required by the operation device and at least one function; the data storage area can store data created according to the use of the abnormality detection device, etc. In addition, the memory 920 can include a high-speed random access memory, and can also include a non-volatile memory, such as at least one magnetic disk storage device, a flash memory device, or other non-volatile solid-state storage device.

[0153] The input device 930 can receive input digital or character information, and generate key signal input related to user settings and function control of the electronic device. The output device 940 can include a display device such as a display screen.

[0154] The one or more modules are stored in the memory 920, and when executed by the one or more processors 910, the abnormality detection method in any of the above-mentioned method embodiments is executed.

[0155] The above-mentioned electronic device product can execute the method provided by the embodiments of the present application, and has the corresponding function modules and beneficial effects of executing the method. Technical details not described in detail in the embodiments can be referred to the method provided by the embodiments of the present application.

[0156] The electronic device of the embodiments of the present application exists in various forms, including but not limited to:

[0157] (1) Mobile communication device: the feature of this kind of device is to have mobile communication function, and to provide voice and data communication as the main target. This kind of terminal includes: smart phone (such as iPhone), multimedia phone, functional phone, and low-end phone, etc.

[0158] (2) Ultra mobile personal computer device: this kind of device belongs to the category of personal computer, has computing and processing function, and generally has mobile internet feature. This kind of terminal includes: PDA, MID and UMPC device, such as iPad.

[0159] (3) Portable entertainment device: this kind of device can display and play multimedia content. This kind of device includes: audio and video player (such as iPod), palm game machine, electronic book, and smart toy and portable car navigation device.

[0160] (4) Server: the device providing computing service, the constitution of server includes processor, hard disk, memory, device bus, etc. The server is similar to general computer architecture, but due to the need to provide high reliable service, the requirements in processing capacity, stability, reliability, security, scalability, manageability, etc. are higher.

[0161] (5) Other electronic devices with data interaction function, such as TV, car-mounted large screen, etc.

[0162] The device embodiments described above are only schematic, wherein the units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, i.e. may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment.

[0163] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be realized by means of software plus necessary general hardware platform, and of course can also be realized by hardware. Based on such understanding, the above technical solutions essentially or said to make contributions to the prior art can be embodied in the form of software product, which can be stored in a computer readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., including a plurality of instructions to make a computer device (which can be a personal computer, server, or network device, etc.) execute the method described in each embodiment or some part of the embodiment.

[0164] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; and although the present application has been described in detail with reference to the foregoing embodiments, it should be appreciated by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An anomaly detection method applied to an IPM module, characterized in that, The method includes: After the electrical equipment enters the power-on standby stage, the upper and lower bridge arms of each phase of the control IPM module are turned off, and the lower bridge arm of each phase of the IPM module is short-circuited based on the current of each phase. After the electrical equipment enters the bootstrap phase, the upper arm of each phase of the IPM module is detected to be short-circuited or the lower arm is open-circuited. Specifically, for any phase, the upper arm of that phase is controlled to turn off, and the duty cycle of the lower arm of that phase is controlled to gradually increase. During the gradual increase of the duty cycle of the lower arm, the upper arm of that phase is determined to be short-circuited or the lower arm is open-circuited based on the duty cycle of the lower arm of that phase and the current of that phase. After the electrical equipment enters the positioning stage, the upper and lower bridge arms of each phase of the IPM module are controlled to conduct according to a preset duty cycle. Then, the upper bridge arm of each phase is determined to be open based on the positive current of each phase.

2. The method according to claim 1, characterized in that, Determining whether the lower bridge arm of each phase of the IPM module is short-circuited based on the phase current includes: Determine whether the current in each phase of the IPM module is zero; If not, then the lower arm of that phase is determined to be short-circuited; If so, it is determined that the lower arm of that phase is not short-circuited.

3. The method according to claim 1, characterized in that, Determine whether the upper arm of a phase is short-circuited or the lower arm is open-circuited based on the duty cycle of the lower arm and the current of that phase, including: When the duty cycle of the lower bridge arm of the phase is less than the first preset threshold, the upper bridge arm of the phase is short-circuited based on the current of the phase. If the upper arm of the phase is not short-circuited, the duty cycle of the lower arm of the phase will continue to be controlled to gradually increase according to the preset step size; When the duty cycle of the lower bridge arm of the phase is greater than the second preset threshold, the current of the phase is used to determine whether the lower bridge arm of the phase is open. Wherein, the second preset threshold is greater than the first preset threshold.

4. The method according to claim 3, characterized in that, When the duty cycle of the lower bridge arm of a phase is less than a first preset threshold, the system determines whether the upper bridge arm of the phase is short-circuited based on the current of that phase, including: When the duty cycle of the lower bridge arm of the phase is less than the first preset threshold, it is determined whether the current of the phase is greater than the overcurrent protection threshold. If so, then the upper arm of that phase is short-circuited; If not, then it is determined that the upper arm of that phase is not short-circuited.

5. The method according to claim 3, characterized in that, When the duty cycle of the lower bridge arm of a phase is greater than a second preset threshold, the system determines whether the lower bridge arm of the phase is open based on the current of that phase, including: When the duty cycle of the lower bridge arm of the phase is greater than the second preset threshold, it is determined whether the current of the phase is 0. If so, then determine that the lower arm of that phase is open. If not, then it is determined that the lower arm of that phase is not open.

6. The method according to claim 1, characterized in that, Determining whether the upper arm of a phase is open-circuited based on the forward current of each phase includes: Determine whether the forward current of each phase is greater than a preset threshold; wherein, the preset threshold = reference value of forward current of each phase * k1; If so, then the upper arm of that phase is determined to be open-circuited; If not, then the upper arm of that phase is determined to be unopened.

7. An anomaly detection device, applied to an IPM module, characterized in that, The anomaly detection device includes: The first detection module is used to control the upper and lower bridge arms of each phase of the IPM module to be turned off after the electrical equipment enters the power-on standby stage, and to determine whether the lower bridge arm of each phase of the IPM module is short-circuited based on the current of each phase. The second detection module is used to detect whether the upper arm of each phase of the IPM module is short-circuited or the lower arm is open-circuited after the electrical equipment enters the bootstrap phase. Specifically, for any phase, the upper arm of the phase is controlled to turn off, and the duty cycle of the lower arm of the phase is controlled to gradually increase. During the gradual increase of the duty cycle of the lower arm, the upper arm of the phase is determined to be short-circuited or the lower arm is open-circuited based on the duty cycle of the lower arm of the phase and the current of the phase. The third detection module is used to control the upper and lower bridge arms of each phase of the IPM module to conduct according to a preset duty cycle after the electrical equipment enters the positioning stage, and then determine whether the upper bridge arm of the phase is open based on the positive current of each phase.

8. An electrical device, comprising a motor and an IPM module, characterized in that, It also includes the anomaly detection device as described in claim 7.

9. The electrical equipment according to claim 8, characterized in that, The electrical equipment is a compressor or a fan.

10. An air conditioning unit, characterized in that, Includes the electrical equipment as described in claim 8 or 9.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method as described in any one of claims 1 to 6.

12. An electronic device, characterized in that, include: One or more processors; A storage device for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement the method as described in any one of claims 1 to 6.

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