Method for detecting multi-resistance sampling circuit, module, electric appliance and air conditioner

Abstract

The application discloses a kind of detection method, module, electric appliance and air conditioner of multi-resistance sampling circuit, after receiving the start command characterizing the motor starts, the plurality of sampling branches are charged, wherein, the charging time interval of any two sampling branches is set, the charging is the bootstrap capacitor of the upper bridge arm in the sampling branch is charged;For each sampling branch, in the process that this sampling branch is charged, the current of each sampling branch is detected, and current data is obtained;According to the current data, it is judged whether the plurality of sampling branches exist short circuit. Through the application, the reliability of the product is further improved to a certain extent.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of household appliances, and particularly relates to a detection method, a detection module, an appliance and an air conditioner of a multi-resistance sampling circuit. BACKGROUND

[0002] In a situation where silence is required, a variable frequency air conditioner is often used, and a variable frequency motor of the variable frequency air conditioner is generally controlled by using a three-resistance sampling circuit.

[0003] At present, a hardware overcurrent protection scheme with a filter circuit is often used to protect the motor from overcurrent, but when the motor is started with a short circuit between any two phases, the hardware overcurrent protection scheme often cannot effectively protect the short-time large pulse current caused by the short circuit, resulting in continuous overcurrent pulse impact and damage to the product. SUMMARY

[0004] The present application aims to at least solve the technical problem of insufficient reliability of products using a multi-sampling circuit, and embodiments of the present application provide a detection method of a multi-resistance sampling circuit, embodiments of the present application also provide a detection module of a multi-resistance sampling circuit, embodiments of the present application also provide an appliance, and embodiments of the present application also provide an air conditioner.

[0005] In a first aspect, embodiments of the present application provide a detection method of a multi-resistance sampling circuit, the multi-resistance sampling circuit comprising a plurality of sampling branches, each of the sampling branches comprising a series connection of an upper bridge arm and a lower bridge arm, the plurality of sampling branches being connected in one-to-one correspondence with a plurality of phases of a motor, and the method comprising: after receiving a start command representing starting of the motor, charging the plurality of sampling branches, wherein charging time periods of any two sampling branches are set to be spaced apart, and the charging is charging a bootstrap capacitor of the upper bridge arm in the sampling branch; for each sampling branch, detecting a current of each of the sampling branches in a process of charging the sampling branch, and obtaining current data; and determining whether a short circuit exists in the plurality of sampling branches according to the current data.

[0006] The above scheme charges the multiple sampling branches of the multi-resistance sampling circuit at intervals after receiving a start command. If there is no short circuit problem in two sampling branches, only the current of the charged sampling branch increases during the charging of any of the two sampling branches. If there is a short circuit problem in two sampling branches, the currents of the two sampling branches are equal or close during the charging of any of the two sampling branches. Therefore, by charging each sampling branch at intervals and detecting the current of each sampling branch, the short circuit of the multiple sampling branches can be accurately determined according to the detected current data, so that the short circuit problem of the multi-resistance sampling circuit or the motor connected thereto can be found in time, and further damage of the product caused by the short circuit can be avoided.

[0007] In some embodiments, each of the sampling branches further comprises a sampling resistor connected in series between the lower bridge arm and the ground terminal; before the charging of the multiple sampling branches, the method further comprises: obtaining a static bias voltage across each of the sampling resistors; and the detecting of the current of each of the sampling branches during the charging of the sampling branch comprises: detecting a current voltage across the sampling resistor in each of the sampling branches during the charging of the sampling branch; and calibrating the current voltage by using the corresponding static bias voltage, and determining the current of each of the sampling branches according to the calibrated current voltage and the resistance value of the corresponding sampling resistor. The calibration of the current voltage by the static bias voltage can effectively avoid interference and improve detection accuracy.

[0008] In some embodiments, the multiple sampling branches are N sampling branches, and N is greater than 1; and the detecting of the current of each of the sampling branches during the charging of the sampling branch comprises: detecting the current of N-1 of the sampling branches and the total current of the multiple sampling branches during the charging of the sampling branch; and determining the current of each of the sampling branches according to the total current and the current of N-1 of the sampling branches. The determination of the current data by using the total current and the branch current increases the richness of the current data acquisition and provides multiple ways of verifying the short circuit.

[0009] In some embodiments, the determining of the short circuit of the multiple sampling branches according to the current data comprises: if the difference between the currents of two sampling branches is less than a preset first difference when each of the two sampling branches is charged, respectively, it is determined that the two sampling branches are short-circuited. Only when the difference between the currents of two sampling branches 10 is less than a preset first difference when each of the two sampling branches 10 is charged, respectively, it is determined that the two sampling branches are short-circuited, which can effectively avoid misjudgment caused by interference.

[0010] In some embodiments, the determining whether the plurality of sampling branches have short circuit according to the current data comprises: if the difference between the current of any sampling branch and the total current of the plurality of sampling branches is greater than a preset second difference when charging the any sampling branch, it is determined that the any sampling branch has short circuit with other sampling branches. The total current is used in combination with the branch current to determine short circuit, which increases the richness of short circuit determination and provides multiple ways to verify short circuit.

[0011] In some embodiments, the charging the plurality of sampling branches comprises: pre-charging the plurality of sampling branches by using a first pulse; and charging the plurality of sampling branches by using a second pulse; the peak value of the second pulse is greater than that of the first pulse; and the detecting the current of each sampling branch during the charging of the sampling branch comprises: detecting the current of each sampling branch during the charging of the sampling branch by using the second pulse, so as to avoid the risk of reliability caused by too large charging current when directly charging for the first time.

[0012] In some embodiments, after the determining whether the plurality of sampling branches have short circuit according to the current data, the method further comprises: if there is short circuit, stopping starting the motor, so as to avoid continuous over-current pulse impact caused by continuing to start the motor in the state of short circuit between motor phases, which leads to damage of other components.

[0013] In a second aspect, a detection module of a multi-resistance sampling circuit is provided, the multi-resistance sampling circuit comprising a plurality of sampling branches, each of the sampling branches comprising a series connection of an upper bridge arm and a lower bridge arm, the plurality of sampling branches being connected in one-to-one correspondence with a plurality of phases of a motor, and the module comprising:

[0014] a charging unit configured to charge the plurality of sampling branches after receiving a start command representing starting of the motor, wherein the charging time periods of any two sampling branches are arranged to be separated, and the charging is charging a bootstrap capacitor of the upper bridge arm in the sampling branch;

[0015] a detection unit configured to detect, for each sampling branch, a current of each of the sampling branches during charging of the sampling branch, and obtain current data;

[0016] a processing unit configured to determine whether the plurality of sampling branches have short circuit according to the current data.

[0017] The above technical solutions improve the reliability of products comprising the detection module.

[0018] In a third aspect, a detection module of a multi-resistance sampling circuit is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the method of the first aspect when executing the program.

[0019] The above technical solution improves the reliability of a product comprising the detection module.

[0020] In a fourth aspect, an electrical appliance is provided, comprising the detection module of the multi-resistance sampling circuit of the second aspect or the third aspect. Thus, the phase-to-phase short circuit of the electrical appliance can be found in advance, and the reliability of the electrical appliance is ensured.

[0021] In a fifth aspect, an air conditioner is provided, comprising the detection module of the multi-resistance sampling circuit of the second aspect or the third aspect. Thus, the phase-to-phase short circuit of the electrical appliance can be found in advance, and the reliability of the electrical appliance is ensured.

[0022] Additional aspects and advantages of embodiments of the present application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following description and the attached drawings. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0024] Figure 1 A schematic diagram of a multi-resistance sampling circuit in an embodiment of the present application is shown Figure One ;

[0025] Figure 2 A flowchart of a detection method of a multi-resistance sampling circuit in an embodiment of the present application is shown

[0026] Figure 3 A schematic diagram of a bootstrap circuit in an embodiment of the present application is shown

[0027] Figure 4 A schematic diagram of a charging timing in an embodiment of the present application is shown

[0028] Figure 5 A schematic diagram of a charging current of a sampling branch without short circuit in an embodiment of the present application is shown

[0029] Figure 6 A schematic diagram of a charging current of a sampling branch with short circuit in an embodiment of the present application is shown

[0030] Figure 7Fig. 1 shows a schematic diagram of a multi-resistance sampling circuit in an embodiment of the present application Figure Two ;

[0031] Figure 8 Fig. 1 shows a schematic diagram of a multi-resistance sampling circuit in an embodiment of the present application Figure Three ;

[0032] Figure 9 Fig. 1 shows a schematic diagram of a multi-resistance sampling circuit in an embodiment of the present application Figure One ;

[0033] Figure 10 Fig. 1 shows a schematic diagram of a multi-resistance sampling circuit in an embodiment of the present application Figure Two . DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of protection of the present application.

[0035] It should be noted that all directional indications in the embodiments of the present application are only used to explain the relative position relationship, movement condition and the like between components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0036] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0037] In addition, the description such as "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection claimed by the present application.

[0038] The embodiment of the present application provides a detection method of a multi-resistance sampling circuit, please refer to Figure 1 and Figure 2 , Figure 1 Fig. 1 is a schematic diagram of a multi-resistance sampling circuit in the embodiment of the present application, Figure 2 Fig. 2 is a flow chart of the detection method of the multi-resistance sampling circuit in the embodiment of the present application. The multi-resistance sampling circuit comprises a plurality of sampling branches 10, each of the sampling branches 10 comprises a series connection of an upper bridge arm 11 and a lower bridge arm 12, the plurality of sampling branches 10 are connected in one-to-one correspondence with a plurality of phase connections of a motor 20, and the method comprises the following steps.

[0039] Step S101, after receiving a starting command representing starting of the motor, charging is performed on the plurality of sampling branches, wherein charging time periods of any two sampling branches are set to be spaced apart, and the charging is charging of a bootstrap capacitor of the upper bridge arm in the sampling branch;

[0040] Step S102, for each sampling branch, detecting a current of each of the sampling branches in the process of charging of the sampling branch, and obtaining current data;

[0041] Step S103, judging whether short circuit exists in the plurality of sampling branches according to the current data.

[0042] It should be noted that the multi-resistance sampling circuit can be as shown in Figure 2 Fig. 1 shows a three-resistance sampling circuit with three sampling branches 10, so as to match a commonly used three-phase motor, and can also be a two-resistance sampling circuit with two sampling branches 10 or a four-resistance sampling circuit with four sampling branches 10, which is not limited herein. The detection method of the multi-resistance sampling circuit can be applied to a processor or a special detection circuit and the like, which is not limited herein.

[0043] It should be noted that the current protection pin can be set on the hardware to protect the motor from overcurrent, the current sampling signal on the sampling resistor 13 in the multi-resistance sampling circuit is input to the current protection pin of the intelligent power module (IPM), the hardware overcurrent protection is provided, and the RC filter circuit is set on the pin of the IPM to avoid interference of the external current protection pin, thereby avoiding false triggering of the module hardware overcurrent protection. After the motor starts, the motor speed starts to rise from zero, the load demand is small at the beginning, and the effective vector is narrow. At this time, if there is a short circuit between any two phases in the motor (for example, a short circuit between any two phases in the U / V / W three-phase), the motor will have a large instantaneous current during startup. However, since the RC filter time constant of the IPM is usually 1-2us, the protection current duration caused by the instantaneous large current of the short circuit is less than the filter time, and the generation time of the instantaneous large current is usually not at the point of time when the software samples the current. Therefore, the current protection pin cannot protect the large pulse current for a short time. If the motor is started continuously in the motor inter-phase short circuit state, continuous overcurrent pulse impact will be generated, which is easy to cause damage to the motor, the IPM or other components.

[0044] The detection method of the multi-resistance sampling circuit provided in the embodiment of the application is adopted, after receiving a start command, the multiple sampling branches 10 of the multi-resistance sampling circuit are charged at intervals, and the current of each sampling branch 10 is detected, and whether the multiple sampling branches 10 have a short circuit (the motor inter-phase short circuit will cause the corresponding sampling branch to have a short circuit) is accurately judged according to the detected current data, so that the short circuit problem of the multi-resistance sampling circuit or the motor 20 connected therewith can be found in time, the further damage of the product caused by the short circuit is effectively avoided, and the reliability is improved.

[0045] The detection method of the multi-resistance sampling circuit provided in the embodiment of the application is described in detail as follows: Figure 1 and Figure 2 The detection method of the multi-resistance sampling circuit provided in the embodiment of the application is described in detail as follows:

[0046] In step S101, after receiving a start command representing starting of the motor, the multiple sampling branches are charged, wherein the charging time periods of any two sampling branches are set at intervals, and the charging is charging of a bootstrap capacitor in the upper arm of the sampling branch.

[0047] Specifically, each sampling branch 10 includes a series of upper bridge arm 11 and lower bridge arm 12, and a plurality of sampling branches 10 are connected one-to-one with a plurality of phase connections of the motor 20. Wherein, the upper bridge arm 11 and the lower bridge arm 12 can be metal oxide semiconductor field effect transistor (MOS) or insulated gate bipolar transistor (IGBT), which is not limited here. As shown in Figure 2 , the upper bridge arm 11 is a transistor: U+, V+, W+, and the lower bridge arm 12 is a transistor: U-, V-, W-. Each sampling branch 10 can also be provided with a sampling resistor 13: R1, R2 and R3. The sampling resistor 13 is connected between the lower bridge arm 12 and the ground terminal GND or the negative terminal of the power supply, for convenient acquisition of the sampling current. As shown in Figure 3 , each sampling branch 10 further includes a bootstrap circuit 14, which includes a high-voltage integrated circuit HVIC for driving the upper bridge arm 11, a low-voltage integrated circuit LVIC for driving the lower bridge arm 12, a current limiting resistor Rx, a bootstrap diode BSD and a bootstrap capacitor BSC, and a power supply. Wherein, the power supply is often 15V, in order to avoid damaging the modules and power devices in the product during charging.

[0048] Each phase connection of the motor 20 is connected to a sampling branch 10, and is specifically connected between the upper bridge arm 11 and the lower bridge arm 12 of the sampling branch 10. By controlling the electric circuit of the motor 20 flowing from the plurality of phase connections through the plurality of sampling branches 10, the direction and / or speed of the motor can be controlled. Taking a three-phase motor as an example, as shown in Figure 2 , the U-phase connection of the three-phase motor is connected to the sampling branch 10 labeled U, the V-phase connection is connected to the sampling branch 10 labeled V, and the W-phase connection is connected to the sampling branch 10 labeled W.

[0049] In an optional embodiment, the start command can be a command issued by a control module that controls the start of the motor 20, or a command sent by the motor 20, or a command that actively monitors the rotation speed of the motor 20 and considers that the start command is received when the rotation speed reaches a preset value, which is not limited here. After receiving the start command representing the start of the motor 20, the plurality of sampling branches 10 are charged at intervals. Wherein, the specific charging method can be to charge the bootstrap capacitor of the upper bridge arm 11 in the sampling branch 10, that is, to charge the bootstrap capacitor BSC in Figure 3 .

[0050] The charging timing requirement for sampling branch 10 is that multiple sampling branches 10 are charged sequentially and at intervals, meaning the charging periods of each sampling branch 10 do not overlap. The charging order of the multiple sampling branches is not specified and can be set as needed. For example, using... Figure 4 The charging timing pairs shown are as follows Figure 2 The multi-resistor sampling circuit shown charges by first applying a pulse to the sampling branch corresponding to U for charging (bootstrapping). After this charging pulse ends, a pulse is applied to the sampling branch corresponding to V for charging (bootstrapping), and after this charging pulse ends, a pulse is applied to the sampling branch corresponding to W for charging (bootstrapping). The charging periods for each branch are separated, and only one sampling branch is charged at a time to avoid interference from short circuits caused by simultaneous charging of multiple sampling branches. The duration of the charging pulse can be determined by the charging time of the bootstrapping circuit, i.e., it depends on the size of the current-limiting resistor Rx and the bootstrapping capacitor BSC.

[0051] Step S102: For each sampling branch, during the charging process of that sampling branch, the current of each sampling branch is detected to obtain current data.

[0052] by Figure 2 For example, when charging the sampling branch 10 corresponding to U, the current of the sampling branches 10 corresponding to U, V, and W is detected simultaneously; when charging the sampling branch 10 corresponding to V, the current of the sampling branches 10 corresponding to U, V, and W is detected simultaneously; when charging the sampling branch 10 corresponding to W, the current of the sampling branches 10 corresponding to U, V, and W is still detected simultaneously.

[0053] Specifically, assuming there is no phase-to-phase short circuit in motor 20 and no short circuits between the sampling branches 10 of the multi-resistor sampling circuit, a sampling branch will only generate current when its own branch is charged. For example, using... Figure 4 The charging timing pairs shown are as follows Figure 2 The multi-resistor sampling circuit shown is used for charging, and will generate [something] when there is no short circuit. Figure 5 The diagram shows the current flow. When there is a phase-to-phase short circuit in motor 20 and a short circuit between each sampling branch 10 of the multi-resistor sampling circuit, if either of the two short-circuited sampling branches 10 is charged, both short-circuited sampling branches will generate current, and the magnitudes of the currents will be close to or equal. For example, assuming a short circuit between phase U and phase V, the following method is used... Figure 4 The charging timing pairs shown are as follows Figure 2 The multi-resistor sampling circuit shown is charged, which will generate Figure 6 The diagram shown illustrates the current flow.

[0054] Therefore, the short circuit problem can be accurately detected by charging the multiple sampling branches through the interval and detecting the branch current. In an optional embodiment, a sampling resistor 13 can be arranged on each sampling branch 10 to improve the convenience of obtaining the current data, i.e., the current of the sampling branch 10 can be conveniently obtained by detecting the voltage value of the sampling resistor 13 and then dividing the voltage value by the resistance value. For example, for the sampling branch 10 with the label U in FIG. 10, the current of the sampling branch 10 can be obtained by using a voltmeter or a micro control unit MCU to obtain the current voltage between the sampling resistor 13 with the label R1 and then dividing the current voltage by the resistance value of R1. Figure 2

[0055] In an optional embodiment, according to the specific circuit arrangement of the multi-resistor sampling circuit, the current of each sampling branch can be detected in multiple ways to obtain the current data, two of which are listed below as examples.

[0056] Firstly, the multi-resistor sampling circuit includes N sampling branches 10, and N is greater than 1. During the charging process of any one of the sampling branches 10, the current of each sampling branch needs to be directly detected. That is, as shown in FIG. 10, a sampling resistor 13 is arranged on each sampling branch 10, so that the current flowing through the sampling resistor 13 is detected to determine the current of the sampling branch. Figure 2

[0057] Secondly, the multi-resistor sampling circuit includes N sampling branches 10, and N is greater than 1. During the charging process of any one of the sampling branches 10, the current of part of the sampling branches is detected, and the current data is obtained in combination with the detection of the total current. Specifically, as shown in FIG. 11, a sampling resistor 13 is arranged on each sampling branch 10, and a total sampling resistor Rs is arranged on the total circuit after the sampling branches are combined. During the charging process of any one of the sampling branches, the currents of N-1 sampling branches 10 and the total current of the multiple sampling branches (the current on the total sampling resistor Rs) are detected. According to the total current and the currents of the N-1 sampling branches 10, the current of each sampling branch can be determined. Specifically, the current of the sampling branch that is not detected can be obtained by subtracting the sum of the currents of the N-1 sampling branches 10 from the total current. Figure 7

[0058] As shown in FIG. 12, only N-1 sampling resistors 13 are arranged on the sampling branches, and a total sampling resistor Rs is arranged on the total circuit after the sampling branches are combined, so that the consumption of the resistor device is saved. Figure 8 Specifically, the second method described above can be used to calculate or verify the branch current by using the total current, which increases the accuracy and provides more abundant current detection methods and current data acquisition methods.

[0059] ​​​​

[0060] In the optional embodiment, the static bias voltage across each sampling resistor 13 can also be detected by the voltage meter or the micro control unit MCU before the plurality of sampling branches 10 are charged, i.e. before the motor 20 is started. Then, during the charging of the sampling branches 10, the current voltage across each sampling resistor 13 in each sampling branch 10 is detected, and the current voltage is calibrated by the corresponding static bias voltage. The current of each sampling branch is determined according to the calibrated current voltage and the resistance value of the corresponding sampling resistor.

[0061] For example, before the motor 20 is started, the static bias voltages of the sampling resistors 13 labeled as R1, R2 and R3 in the sampling branch 10 of the motor 20 are detected, and the static bias voltages are V1, V2 and V3 respectively. During the charging of the sampling branch 10, the current voltages across the sampling resistors 13 in each sampling branch 10 are detected, and the current voltages are V1', V2' and V3' respectively. Then, the current voltages are corrected as V1'-V1, V2'-V2 and V3'-V3. The sampling currents are calculated as (V1'-V1)÷R1, (V2'-V2)÷R2 and (V3'-V3)÷R3 respectively according to the corrected current voltages. Figure 2

[0062] Of course, when the circuit shown in the second sampling method is used to detect the current, the static bias voltages across the N-1 sampling resistors and the static bias voltage across the total resistor can be obtained first. During the charging of any sampling branch, the current voltages across the N-1 sampling resistors and the current voltage across the total resistor are detected. Then, the current voltages are calibrated by the corresponding static bias voltages, and the currents of the N-1 sampling branches and the total current are determined according to the calibrated current voltages and the resistance values of the corresponding sampling resistors or the total resistor. Figure 7 Figure 8 Specifically, the static bias voltage is detected before the motor 20 is started, and the static bias voltage is used to calibrate the current voltage during the detection of the current, which can effectively avoid external interference and increase the accuracy of the detected current, thereby ensuring the accuracy of the short circuit detection.

[0063] Specifically, the static bias voltage is detected before the motor 20 is started, and the static bias voltage is used to calibrate the current voltage during the detection of the current, which can effectively avoid external interference and increase the accuracy of the detected current, thereby ensuring the accuracy of the short circuit detection.

[0064] ​​In an optional embodiment, the first pulse can be used to pre-charge the sampling branches, and then the second pulse can be used to charge the plurality of sampling branches, wherein the peak value of the second pulse is greater than that of the first pulse. That is, before formally charging each sampling branch, the first pulse with a smaller current or voltage is used for pre-charging to avoid the risk of excessive charging current caused by directly charging with the second pulse for the first time. Then, the current of each sampling branch is detected during the charging process of the second pulse.

[0065] In step S103, whether the plurality of sampling branches have a short circuit is determined according to the current data.

[0066] The short circuit determination can be based on the following principle: when any one of the two short-circuited sampling branches 10 is charged, the other short-circuited sampling branch 10 also generates a current, and the current is close to or equal to the current of the other short-circuited sampling branch 10. Based on the above principle, there are various methods for determining whether there is a short circuit according to the current data, two of which are listed below as examples:

[0067] First, if the difference between the currents of the two sampling branches 10 is less than a preset first difference when each of the two sampling branches 10 is charged, it is determined that the two sampling branches have a short circuit. The first difference is an empirical or theoretical value.

[0068] For example, if the currents of the sampling branch 10 labeled U and the sampling branch 10 labeled V are equal or close when the sampling branch 10 labeled U is charged, it is preliminarily determined that the U and V phases have a short circuit. In order to avoid false positives caused by external interference, if the currents of the sampling branch 10 labeled U and the sampling branch 10 labeled V are still equal or close when the sampling branch 10 labeled V is charged, it is confirmed that the U and V phases have a short circuit. Otherwise, it is not determined that the U and V phases have a short circuit.

[0069] Specifically, only when the difference between the currents of the two sampling branches 10 is less than a preset first difference when each of the two sampling branches 10 is charged, it is determined that the two sampling branches have a short circuit, which can effectively avoid false positives caused by interference.

[0070] Second, if the difference between the current of any sampling branch and the total current of the plurality of sampling branches is greater than a preset second difference when the any sampling branch is charged, it is determined that the any sampling branch has a short circuit with other sampling branches. The second difference is an empirical or theoretical value. The total current value when there is a short circuit is often twice or three times the current of the short-circuited sampling branch, twice representing two short-circuited sampling branches, and three times representing three short-circuited sampling branches.

[0071] For example, assuming that the sampling branch 10 with label U is boosted charged, the difference between the total current of the sampling branch and the current of the sampling branch 10 with label U is greater than a preset second difference (or the total current is twice the current of the sampling branch), it is determined that there is a short circuit between the U phase and other phases.

[0072] After it is determined that there is a short circuit through step S103, the starting motor 20 is stopped, so as to avoid continuous overcurrent pulse impact if the motor continues to be started in the state of the inter-phase short circuit of the motor, and to avoid damage to the motor, the IPM or other components.

[0073] Specifically, after receiving a starting command, the multiple sampling branches of the multi-resistance sampling circuit are charged at intervals. If there is no short circuit problem in two sampling branches, only the current of the sampling branch being charged increases in the process of charging any of the two sampling branches. If there are two sampling branches with a short circuit problem, the currents of the two sampling branches are equal or close when any of the two sampling branches is charged. Therefore, by charging each sampling branch at intervals and detecting the current of each sampling branch, whether the multiple sampling branches have a short circuit can be accurately determined according to the detected current data, so that the short circuit problem of the multi-resistance sampling circuit or the motor connected thereto can be found in time, and further damage of the product caused by the short circuit can be avoided. In the detection process, since the bootstrap circuit power supply voltage is generally within 15V, there is no large current in the loop at all times, and no damage to the module or power device is caused. No effective vector is generated in the detection process, so no noise is caused. Moreover, no additional circuit device is needed, the algorithm is simple and reliable, and the cost is low.

[0074] Based on the same inventive concept, the embodiments of the present application also provide a detection module of a multi-resistance sampling circuit, as shown in Figure 2 The multi-resistance sampling circuit includes multiple sampling branches 10, each of the sampling branches 10 includes a series connection of an upper bridge arm 11 and a lower bridge arm 12, and the multiple sampling branches 10 are connected in one-to-one correspondence with multiple phases of a motor 20, as shown in Figure 9 The detection module of the multi-resistance sampling circuit includes:

[0075] A charging unit 901 is configured to charge the multiple sampling branches after receiving a starting command representing starting of the motor, wherein the charging time periods of any two sampling branches are arranged at intervals, and the charging is charging of a bootstrap capacitor of the upper bridge arm in the sampling branch;

[0076] A detection unit 902 is configured to, for each sampling branch, detect the current of each sampling branch in the process of charging the sampling branch, and obtain current data.

[0077] The processing unit 903 is configured to determine whether short circuit exists in the plurality of sampling branches according to the current data.

[0078] In some embodiments, each of the sampling branches further comprises a sampling resistor connected in series between the lower bridge arm and the ground terminal; and the detection module further comprises an acquisition unit configured to acquire a static bias voltage across each of the sampling resistors.

[0079] The detection unit 902 is further configured to detect a current voltage across the sampling resistor in each of the sampling branches during the charging of the sampling branch; calibrate the current voltage by using the corresponding static bias voltage; and determine the current of each of the sampling branches according to the calibrated current voltage and the resistance value of the corresponding sampling resistor.

[0080] In some embodiments, the plurality of sampling branches comprises N sampling branches, and N is greater than 1; and the detection unit 902 is further configured to detect the current of N-1 sampling branches and the total current of the plurality of sampling branches during the charging of the sampling branch; and determine the current of each of the sampling branches according to the total current and the current of the N-1 sampling branches.

[0081] In some embodiments, the processing unit 903 is further configured to determine that the two sampling branches are short-circuited if the difference between the currents of the two sampling branches is less than a preset first difference when each of the two sampling branches is charged respectively.

[0082] In some embodiments, the processing unit 903 is further configured to determine that the any sampling branch is short-circuited with other sampling branches if the difference between the current of the any sampling branch and the total current of the plurality of sampling branches is greater than a preset second difference when the any sampling branch is charged.

[0083] In some embodiments, the charging unit 901 is further configured to pre-charge the plurality of sampling branches by using a first pulse; and charge the plurality of sampling branches by using a second pulse; and the peak value of the second pulse is greater than that of the first pulse.

[0084] The detection unit 902 is further configured to detect the current of each of the sampling branches during the charging of the sampling branch by using the second pulse.

[0085] In some embodiments, the detection module further comprises a stopping unit configured to stop starting the motor if short circuit exists.

[0086] Based on the same inventive concept, the embodiments of the present application provide a detection module of a multi-resistance sampling circuit, which is described in detail with reference to Figure 10As shown, the detection module of the multi-resistance sampling circuit includes a memory 1001, a processor 1002, and a code 1003 stored in the memory 1001 and executable on the processor, and the processor 1002 implements any of the embodiments of the detection method of the multi-resistance sampling circuit in the foregoing when executing the code.

[0087] Based on the same inventive concept, the embodiments of the present application provide an electric appliance including the detection module of the multi-resistance sampling circuit described in any of the foregoing specific embodiments. In the electric appliance, the specific implementation details of the detection module of the multi-resistance sampling circuit can be referred to the foregoing, and other implementation details can be referred to the related art, and for the sake of brevity of the description, will not be repeated here.

[0088] Based on the same inventive concept, the embodiments of the present application provide an air conditioner including the detection module of the multi-resistance sampling circuit described in any of the foregoing specific embodiments. In the air conditioner, the specific implementation details of the detection module of the multi-resistance sampling circuit can be referred to the foregoing, and other implementation details can be referred to the related art, and for the sake of brevity of the description, will not be repeated here.

[0089] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0090] The present application is described with reference to flowcharts and / or block diagrams of the method, device (system), and computer program product according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions executed by the computer or other programmable data processing apparatus generate a means for implementing the functions specified in the flowcharts and / or block diagrams. Figure One The functions specified in one or more flows and / or blocks Figure One The means for implementing the functions specified in one or more flows and / or blocks.

[0091] These computer program instructions can also be stored in a computer-readable memory capable of guiding the computer or other programmable data processing apparatus to work in a specific manner, so that the instructions stored in the computer-readable memory produce a product including instruction means, which implements the functions specified in the flowcharts and / or block diagrams. Figure One The functions specified in one or more flows and / or blocksFigure One the function specified in the one or more blocks.

[0092] These computer program instructions can also be loaded into computer or other programmable data processing devices, so that a series of operations steps are performed on the computer or other programmable data processing devices to generate computer-implemented processes, thus the instructions executed on the computer or other programmable data processing devices provide the steps for implementing the processes in the flow Figure One Figure One the function specified in the one or more blocks.

[0093] Although preferred embodiments of the application have been described herein, changes and modifications can be suggested to one skilled in the art, and it is intended that the application encompass such changes and modifications as fall within the scope of the appended claims. The patent claims recited herein are intended to encompass the preferred embodiments of the application as well as modifications that are deemed to fall within the scope of the application.

[0094] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described herein.​

Claims

1. A method of detecting a multi-resistance sampling circuit, characterized by, The multi-resistance sampling circuit comprises a plurality of sampling branches, each of the sampling branches comprising a series connection of an upper bridge arm and a lower bridge arm, the plurality of sampling branches being connected in one-to-one correspondence with a plurality of phases of the motor, and the method comprises: after receiving a start command representing starting of the motor, charging the plurality of sampling branches, wherein charging time periods of any two sampling branches are set to be spaced apart, and the charging is charging a bootstrap capacitor of the upper bridge arm in the sampling branch; for each sampling branch, detecting a current of each of the sampling branches in a process of charging the sampling branch, to obtain current data; judging whether short circuit exists in the plurality of sampling branches according to the current data; the charging of the plurality of sampling branches comprises: pre-charging the plurality of sampling branches by using a first pulse; and charging the plurality of sampling branches by using a second pulse, wherein a peak value of the second pulse is greater than that of the first pulse; the detecting of the current of each of the sampling branches in the process of charging the sampling branch comprises: detecting the current of each of the sampling branches in a process of charging the sampling branch by using the second pulse.

2. The method of claim 1, wherein, each of the sampling branches further comprises a sampling resistor, which is connected in series between the lower bridge arm and a ground terminal; before the charging of the plurality of sampling branches, further comprising: obtaining a static bias voltage across each of the sampling resistors; the detecting of the current of each of the sampling branches in the process of charging the sampling branch comprises: detecting a current voltage across the sampling resistor in each of the sampling branches in the process of charging the sampling branch; calibrating the current voltage by using the corresponding static bias voltage; and determining the current of each of the sampling branches according to the calibrated current voltage and a resistance value of the corresponding sampling resistor.

3. The method of claim 1, wherein, the plurality of sampling branches are N sampling branches, N is greater than 1, and the detecting of the current of each of the sampling branches in the process of charging the sampling branch comprises: detecting currents of N-1 sampling branches and a total current of the plurality of sampling branches in the process of charging the sampling branch; determining the current of each of the sampling branches according to the total current and the currents of the N-1 sampling branches.

4. The method of claim 1, wherein, the judging of whether short circuit exists in the plurality of sampling branches according to the current data comprises: if a difference between the currents of two sampling branches is less than a preset first difference when each of the two sampling branches is charged, it is determined that the two sampling branches are short-circuited.

5. The method of claim 1, wherein, the judging of whether short circuit exists in the plurality of sampling branches according to the current data comprises: if a difference between a current of any sampling branch and a total current of the plurality of sampling branches is greater than a preset second difference when the any sampling branch is charged, it is determined that the any sampling branch is short-circuited with other sampling branches.

6. The method of any one of claims 1-5, wherein, after the judging of whether short circuit exists in the plurality of sampling branches according to the current data, further comprising: if short circuit exists, stopping starting the motor.

7. A detection module of a multi-resistance sampling circuit, characterized in that, The multi-resistance sampling circuit comprises a plurality of sampling branches, each of the sampling branches comprising a series connection of an upper bridge arm and a lower bridge arm, the plurality of sampling branches being connected in one-to-one correspondence with a plurality of phases of the motor, and the module comprises: a charging unit configured to charge the plurality of sampling branches after receiving a start command representing starting of the motor, wherein charging time periods of any two sampling branches are set to be spaced apart, and the charging is charging a bootstrap capacitor of the upper bridge arm in the sampling branch; a detection unit configured to detect, for each sampling branch, a current of each of the sampling branches during charging of the sampling branch, and obtain current data; a processing unit configured to determine, according to the current data, whether short circuit exists in the plurality of sampling branches; the charging unit is configured to pre-charge the plurality of sampling branches by using a first pulse, and charge the plurality of sampling branches by using a second pulse, wherein a peak value of the second pulse is greater than that of the first pulse; the detection unit is configured to detect, for each sampling branch, a current of each of the sampling branches during charging of the sampling branch by using the second pulse.

8. A detection module of a multi-resistance sampling circuit, characterized in that, A computer program product comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method of any one of claims 1-6 when executing the program.

9. An electrical appliance characterized by A detection module comprising the multi-resistance sampling circuit of any one of claims 7-8.

10. An air conditioner characterized by comprising: A detection module comprising the multi-resistance sampling circuit of any one of claims 7-8.

Images