Fault detection method and device, equipment, storage medium and program product

Abstract

The invention provides a fault detection method, device and equipment, a storage medium and a program product, and belongs to the technical field of three-phase step-down converters. By adopting the technical scheme, whether the three-phase step-down converter has the short-circuit fault is determined through the voltage sampling values of the bridge arm switch in different states, so that the short-circuit fault of the three-phase step-down converter can be found in time, the short-circuit fault can be solved in time, and power interruption is prevented.

Description

Technical Field

[0001] The present disclosure relates to the technical field of three-phase buck converters, and particularly to a method, device, equipment, storage medium, and program product for fault detection. Background Art

[0002] Three-phase buck converters play an important role in maintaining the safe and stable operation of power systems. A three-phase buck converter generally converts alternating current into direct current and supplies power to electrical equipment. Once a converter fails, it will cause a power interruption. Summary of the Invention

[0003] To solve the related technical problems, the present disclosure provides a method, device, equipment, storage medium, and program product for fault detection. The technical solutions are as follows:

[0004] In a first aspect, a method for fault detection is provided. The method is applied to a three-phase buck converter, which includes a controller, a pre-charge switch, multiple leg switches, and a voltage sampling circuit. The input end of the three-phase buck converter is electrically connected to an AC power supply, and the output end of the three-phase buck converter is electrically connected to electrical equipment;

[0005] The method includes:

[0006] The controller controls each leg switch to enter a specified state respectively and controls the pre-charge switch to be turned on;

[0007] The controller obtains the sampling value of the voltage sampling circuit;

[0008] When the sampling value of the voltage sampling circuit meets the specified condition, the controller determines that a short-circuit fault has occurred.

[0009] In a possible implementation, the controller controls each leg switch to enter a specified state respectively, including:

[0010] The controller controls each leg switch to be turned off;

[0011] The controller determines a short-circuit fault, including:

[0012] The controller determines that a leg short-circuit fault has occurred in the three-phase buck converter.

[0013] In a possible implementation, the controller controls each leg switch to enter a specified state respectively, including:

[0014] The controller controls the leg switches of the first phase to be turned on and controls the leg switches of the second and third phases to be turned off;

[0015] The controller determines a short - circuit fault, including:

[0016] The controller determines that a short - circuit fault occurs in the arm of the second or third phase of the three - phase buck converter.

[0017] In a possible implementation, the controller controls each arm switch to enter a specified state, including:

[0018] The controller turns on the arm switch of the upper arm of the first phase, and turns off the arm switches of the lower arm of the first phase, the upper arms of the second and third phases, and the lower arms of the second and third phases.

[0019] The controller determines a short - circuit fault, including:

[0020] The controller determines that a short - circuit fault occurs in the lower arm of the second or third phase of the three - phase buck converter.

[0021] In a possible implementation, the controller controls each arm switch to enter a specified state, including:

[0022] The controller turns on the arm switch of the lower arm of the first phase, and turns off the arm switches of the upper arm of the first phase, the upper arms of the second and third phases, and the lower arms of the second and third phases.

[0023] The controller determines a short - circuit fault, including:

[0024] The controller determines that a short - circuit fault occurs in the upper arm of the second or third phase of the three - phase buck converter.

[0025] In a possible implementation, the specified condition is that the voltage increment of the sampling value of the voltage sampling circuit relative to the previous sampling value is greater than the first voltage increment threshold; or, the sampling value of the voltage sampling circuit is greater than the first voltage threshold.

[0026] In a possible implementation, the controller controls each arm switch to enter a specified state, including:

[0027] The controller turns on each arm switch;

[0028] The controller determines a short - circuit fault, including:

[0029] The controller determines that a short - circuit fault occurs at the output terminal of the three - phase buck converter.

[0030] In a possible implementation, the specified condition is:

[0031] Within a specified duration when the sampled value of the voltage sampling circuit starts to increase from 0, the voltage increment of the sampled value collected relative to the previous sampled value is less than the second voltage increment threshold; or,

[0032] After the sampled value of the voltage sampling circuit starts to increase for a specified duration from 0, the sampled value collected is less than the second voltage threshold.

[0033] In a possible implementation manner, after determining the short - circuit fault, the method further includes:

[0034] The controller controls the pre - charge switch to disconnect.

[0035] In a second aspect, a fault detection device is provided. The device is applied to a three - phase buck converter. The three - phase buck converter includes a controller, a pre - charge switch, multiple leg switches, and a voltage sampling circuit. The input end of the three - phase buck converter is electrically connected to an AC power supply, and the output end of the three - phase buck converter is electrically connected to an electrical device;

[0036] The device includes:

[0037] A control module, configured to control each leg switch to enter a specified state respectively and control the pre - charge switch to be turned on;

[0038] An acquisition module, configured to acquire the sampled value of the voltage sampling circuit;

[0039] A determination module, configured to determine that a short - circuit fault occurs when the sampled value of the voltage sampling circuit meets a specified condition.

[0040] In a possible implementation manner, the control module is configured to:

[0041] Control each leg switch to be turned off;

[0042] The determination module is configured to:

[0043] Determine that a leg short - circuit fault occurs in the three - phase buck converter.

[0044] In a possible implementation manner, the control module is configured to:

[0045] Control the leg switches of the first phase to be turned on and control the leg switches of the second phase and the third phase to be turned off;

[0046] The determination module is configured to:

[0047] Determine that a leg short - circuit fault occurs in the second phase or the third phase of the three - phase buck converter.

[0048] In a possible implementation manner, the control module is configured to:

[0049] Turn on the leg switch of the upper leg of the first phase, and turn off the leg switches of the lower leg of the first phase, the upper legs of the second and third phases, and the lower legs of the second and third phases;

[0050] The determining module is configured to:

[0051] Determine that a leg short - circuit fault occurs in the lower leg of the second or third phase of the three - phase buck converter.

[0052] In a possible implementation, the control module is configured to:

[0053] Turn on the leg switch of the lower leg of the first phase, and turn off the leg switches of the upper leg of the first phase, the upper legs of the second and third phases, and the lower legs of the second and third phases;

[0054] The determining module is configured to:

[0055] Determine that a leg short - circuit fault occurs in the upper leg of the second or third phase of the three - phase buck converter.

[0056] In a possible implementation, the specified condition is that the voltage increment of the sampling value of the voltage sampling circuit relative to the previous sampling value is greater than the voltage increment threshold; or, the sampling value of the voltage sampling circuit is greater than the first voltage threshold.

[0057] In a possible implementation, the control module is configured to:

[0058] Turn on each leg switch;

[0059] The determining module is configured to:

[0060] Determine that a short - circuit fault occurs at the output end of the three - phase buck converter.

[0061] In a possible implementation, the specified condition is:

[0062] Within a specified duration when the sampling value of the voltage sampling circuit starts to increase from 0, the voltage increment of the collected sampling value relative to the previous sampling value is less than the second voltage increment threshold; or,

[0063] After the sampling value of the voltage sampling circuit starts to increase from 0 for a specified duration, the collected sampling value is less than the second voltage threshold.

[0064] In a possible implementation, the control module is further configured to:

[0065] Turn off the pre - charge switch.

[0066] In a third aspect, a computer device is provided. The computer device includes a memory and a processor. The memory is used to store computer instructions, and the processor executes the computer instructions stored in the memory so that the computer device executes the method provided in the first aspect and its possible implementation manners.

[0067] In a fourth aspect, a computer-readable storage medium is provided. The computer-readable storage medium stores computer program code, and when the computer program code is executed by a computer device, the computer device executes the method provided in the first aspect and its possible implementation manners.

[0068] In a fifth aspect, a computer program product is provided. The computer program product includes computer program code, and when the computer program code is executed by a computer device, the computer device executes the method provided in the first aspect and its possible implementation manners.

[0069] By adopting this solution, whether a three-phase buck converter has a short-circuit fault is determined through the voltage sampling values in different states of the leg switches. In this way, the short-circuit fault of the three-phase buck converter can be detected in time, so as to solve the short-circuit fault in time and prevent power interruption. Description of the Drawings

[0070] Figure 1 is a schematic structural diagram of a three-phase buck converter provided by an embodiment of the present disclosure;

[0071] Figure 2 is a schematic diagram of a method processing flow for fault detection provided by an embodiment of the present disclosure;

[0072] Figure 3 is a schematic diagram of a processing flow for fault detection provided by an embodiment of the present disclosure;

[0073] Figure 4 is a schematic diagram of sampling values of a voltage provided by an embodiment of the present disclosure;

[0074] Figure 5 is a schematic diagram of a processing flow for fault detection provided by an embodiment of the present disclosure;

[0075] Figure 6 is a schematic diagram of a processing flow for fault detection provided by an embodiment of the present disclosure;

[0076] Figure 7 is a schematic diagram of sampling values of a voltage provided by an embodiment of the present disclosure;

[0077] Figure 8 is a schematic structural diagram of a device for fault detection provided by an embodiment of the present disclosure. Detailed Embodiments

[0078] To make the objectives, technical solutions, and advantages of the present disclosure clearer, the following will further describe in detail the embodiments of the present application with reference to the accompanying drawings.

[0079] The present disclosure provides a method for fault detection, which is applied to a three-phase buck converter 01. Figure 1 FIG. 6 is a schematic structural diagram of a three-phase buck converter provided by an embodiment of the present disclosure. The three-phase buck converter 01 may include a controller, a pre-charge switch 2, a plurality of leg switches 3, and a voltage sampling circuit. The input terminal 5 of the three-phase buck converter 01 is electrically connected to an AC power supply, and the output terminal 6 of the three-phase buck converter 01 is electrically connected to an electrical device, which may be an air conditioner or the like. Each upper leg and lower leg of each phase are respectively provided with a leg switch 3.

[0080] Three-phase alternating current may be respectively connected to the input terminal 5 of the three-phase buck converter 01. A pre-charge switch 2 and an inductor 7 are provided for each phase. The pre-charge switch 2 is connected to a pre-charge resistor, which can prevent excessive current from damaging the circuit. Optionally, a pre-charge switch 2 may also be provided for any two of the three phases, and no pre-charge switch 2 is provided for the other phase. For example, Figure 1 as shown in FIG. 10, a pre-charge switch 2 is respectively provided for the first phase and the second phase, and no pre-charge switch 2 is provided for the third phase. In this way, even if the third phase is turned on, since the pre-charge switches 2 of the first phase and the second phase are not turned on, the third phase will not form a loop, so there is no possibility of damaging the circuit.

[0081] For example, Figure 1 as shown in FIG. 16, the first phase of the three-phase buck converter 01 includes two leg switches and two diodes, namely a first upper leg switch 311, a first lower leg switch 312, a first diode 811, and a second diode 812. The input terminal 811a of the first diode 811 of the first phase is connected to the output terminal 71a of the first inductor 71. The output terminal 811b of the first diode 811 is connected to the input terminal 311a of the first upper leg switch 311. The input terminal 312a of the first lower leg switch 312 of the first phase is connected to the output terminal 71a of the first inductor 71. The output terminal 312b of the first lower leg switch 312 is connected to the input terminal 812a of the second diode 812. The output terminal 311b of the first upper leg switch 311 is connected to the fourth inductor 74. The output terminal 812b of the second diode 812 is connected to the fifth inductor 75.

[0082] The input terminal 821a of the third diode 821 of the second phase is connected to the output terminal 72a of the second inductor 72. The output terminal 821b of the third diode 821 is connected to the input terminal 321a of the second upper-bridge-arm switch 321. The input terminal 322a of the second lower-bridge-arm switch 322 of the second phase is connected to the output terminal 72a of the second inductor 72. The output terminal 322b of the second lower-bridge-arm switch 322 is connected to the input terminal 822a of the fourth diode 822. The output terminal 321b of the second upper-bridge-arm switch 321 is connected to the fourth inductor 74. The output terminal 822b of the fourth diode 822 is connected to the fifth inductor 75.

[0083] The input terminal 831a of the fifth diode 831 of the third phase is connected to the output terminal 73a of the third inductor 73. The output terminal 831b of the fifth diode 831 is connected to the input terminal 331a of the third upper-bridge-arm switch 331. The input terminal 332a of the third lower-bridge-arm switch 332 of the third phase is connected to the output terminal 73a of the third inductor 73. The output terminal 332b of the third lower-bridge-arm switch 332 is connected to the input terminal 832a of the sixth diode 832. The output terminal 331b of the third upper-bridge-arm switch 331 is connected to the fourth inductor 74. The output terminal 832b of the sixth diode 832 is connected to the fifth inductor 75.

[0084] The controller can be a microcontroller unit (MCU), a digital signal processor (DSP), or the like.

[0085] In a possible implementation, the processing flow for fault detection of the three-phase buck converter 01 can be as Figure 2 shown, including the following steps:

[0086] 201. The controller controls each bridge-arm switch 3 to enter a specified state respectively, and controls the pre-charge switch 2 to be turned on.

[0087] The controller controlling each bridge-arm switch 3 to enter a specified state can include the following situations.

[0088] Situation 1: The controller controls each bridge-arm switch 3 to be turned off.

[0089] Situation 2: The controller controls the bridge-arm switches 3 of the first phase to be turned on, and controls the bridge-arm switches 3 of the second and third phases to be turned off.

[0090] Situation 3: The controller controls each bridge-arm switch 3 to be turned on.

[0091] The controller controls the leg switch 3 to enter the specified state according to the above possible situations, and controls the pre-charge switch 2 to be turned on. The control instructions for the leg switch 3 and the pre-charge switch 2 are issued simultaneously, but the leg switch 3 and the pre-charge switch 2 do not necessarily receive the control instructions at the same time.

[0092] In 202, the controller obtains the sampling value of the voltage sampling circuit.

[0093] For example Figure 1 As shown, the two ends of the voltage sampling circuit are respectively at Figure 1 positions A and B in. The voltage sampling circuit has two functions. One is to monitor the voltage of the DC bus in real time when the three-phase buck converter 01 is operating normally. The other is to sample the voltage of the DC bus during fault detection. The sampling frequency can be preset by technicians, such as sampling once every 40 microseconds, etc.

[0094] In addition, the input voltage of each phase and the DC bus voltage can be detected in real time. The three-phase input voltage is divided into 12 sectors. By obtaining the three-phase input voltage and the DC bus voltage, the controller can determine the duty cycle of each phase. The duty cycle refers to the percentage of the time when the circuit is turned on in the entire circuit working cycle, and is generally a value less than 1. For example, if the first phase of the three-phase buck converter 01 is turned on for half of a working cycle, then the duty cycle of the first phase is 50%. If the input voltage of this phase is 5 volts, the actual effective voltage is 2.5 volts. The calculation formula for the duty cycle of the largest phase of the three-phase buck converter 01 is The calculation formula for the duty cycle of the middle phase is The calculation formula for the duty cycle of the smallest phase is Among them, v ga is the input voltage of the first phase, v gb is the input voltage of the second phase, v gc is the input voltage of the third phase V ref is the DC bus voltage. In this way, the three-phase buck converter 01 can start slowly from 0 voltage.

[0095] In 203, when the sampling value of the voltage sampling circuit meets the specified conditions, the controller determines that a short-circuit fault has occurred.

[0096] Short-circuit faults at different positions correspond to different specified conditions. The three-phase buck converter 01 may have a short-circuit fault in the leg or at the output end. The specific specified conditions will be described in detail in the following process and will not be elaborated here.

[0097] After determining the short-circuit fault, the controller controls each pre-charge switch 2 to be turned off. After that, technicians can repair the position where the short-circuit fault occurred.

[0098] In a possible implementation, the processing flow of fault detection can be as follows Figure 3 as shown, including the following steps:

[0099] 301. The controller controls each leg switch 3 to be turned off and controls the pre-charge switch 2 to be turned on.

[0100] 302. The controller obtains the sampling value of the voltage sampling circuit. When the sampling value of the voltage sampling circuit meets the specified condition, it is determined that a leg short-circuit fault has occurred.

[0101] The specified condition is that the voltage increment of the sampling value of the voltage sampling circuit relative to the previous sampling value is greater than the first voltage increment threshold. The sampling frequency can be preset by the technician, for example, sampling once every 40 microseconds. The first voltage increment threshold can also be preset by the technician, for example, 5 volts, 10 volts, etc. For example, the previous sampling value of the voltage sampling circuit is 200 volts, and the current sampling value of the voltage sampling circuit is 201 volts. The voltage increment is 1 volt, which is less than the first voltage increment threshold of 5 volts. Therefore, the current sampling value of the voltage sampling circuit does not meet the specified condition. Or, the specified condition is that the sampling value of the voltage sampling circuit is greater than the first voltage threshold. The first voltage threshold can be preset by the technician, for example, 200 volts, etc. For example, the current sampling value of the voltage sampling circuit is 201 volts, which is greater than the first voltage threshold of 200 volts. Therefore, the current sampling value of the voltage sampling circuit meets the specified condition. For example Figure 4 as shown, if it is detected that the first voltage increment in the OA segment (within the specified duration when the sampling value starts to increase from 0) is greater than the increment threshold, it can be determined that the specified condition is met. If it is detected that the sampling value in the AB segment (after the specified duration when the sampling value starts to increase from 0) is greater than the first voltage threshold, it can be determined that the specified condition is met.

[0102] At this time, it can be determined that a leg short-circuit fault has occurred in the three-phase buck converter 01, but it cannot be determined which phase has a leg short-circuit fault, nor can it be determined how many phases have a leg short-circuit fault.

[0103] 303. The controller controls the leg switch 3 of the first phase to be turned on and controls the leg switches 3 of the second and third phases to be turned off. When the sampling value of the voltage sampling circuit meets the specified condition, it is determined that a leg short-circuit fault has occurred in the second or third phase of the three-phase buck converter 01. When the sampling value of the voltage sampling circuit does not meet the specified condition, it is determined that a leg short-circuit fault has occurred in the first phase of the three-phase buck converter 01.

[0104] In this way, when the sampling value of the voltage sampling circuit meets the specified condition, it can be determined that at least one of the second or third phases has a leg short-circuit fault.

[0105] When the sampling value of the voltage sampling circuit does not meet the specified conditions, it is determined that no arm short - circuit fault occurs in the second and third phases of the three - phase buck converter 01, and then an arm short - circuit fault occurs in the first phase of the three - phase buck converter 01.

[0106] In addition, when the sampling value of the voltage sampling circuit meets the specified conditions, the controller controls the arm switch 3 of the second phase to turn on, and controls the arm switches 3 of the first and third phases to turn off, and determines that an arm short - circuit fault occurs in the first or third phase of the three - phase buck converter 01. The controller controls the arm switch 3 of the third phase to turn on, and controls the arm switches 3 of the first and second phases to turn off. When the sampling value of the voltage sampling circuit meets the specified conditions, it is determined that an arm short - circuit fault occurs in the first or second phase of the three - phase buck converter 01. These two situations are similar to the above - mentioned judgment method of controlling the arm switch 3 of the first phase to turn on and controlling the arm switches 3 of the second and third phases to turn off, and will not be elaborated here.

[0107] After determining that an arm short - circuit fault occurs in the three - phase buck converter 01, the pre - charge switch 2 is turned off, and an arm short - circuit fault signal is issued. The arm short - circuit fault signal can be a signal lamp, a prompt tone, etc.

[0108] In a possible implementation, the processing flow of fault detection can be as Figure 5 shown, including the following steps:

[0109] 501. The controller controls each arm switch 3 to turn off, and controls the pre - charge switch 2 to turn on.

[0110] 502. The controller obtains the sampling value of the voltage sampling circuit. When the sampling value of the voltage sampling circuit meets the specified conditions, it is determined that an arm short - circuit fault occurs.

[0111] At this time, it can be determined that an arm short - circuit fault occurs in the three - phase buck converter 01, but it cannot be determined which phase has the arm short - circuit fault, nor can it be determined how many phases have the arm short - circuit fault.

[0112] 503. The controller controls the arm switch 3 of the upper arm of the first phase to turn on, and controls the arm switches 3 of the lower arm of the first phase, the upper arms of the second and third phases, and the lower arms of the second and third phases to turn off.

[0113] 504. The controller obtains the sampling value of the voltage sampling circuit. When the sampling value of the voltage sampling circuit meets the specified conditions, the controller determines that an arm short - circuit fault occurs in the lower arm of the second or third phase of the three - phase buck converter 01. When the sampling value of the voltage sampling circuit does not meet the specified conditions, the controller determines that an arm short - circuit fault occurs in the lower arm of the first phase of the three - phase buck converter 01.

[0114] In this way, when the sampling value of the voltage sampling circuit meets the specified conditions, it can be determined that at least one of the lower arm of the second phase or the lower arm of the third phase has a short circuit fault in the bridge arm.

[0115] When the sampling value of the voltage sampling circuit does not meet the specified conditions, it is determined that there is no short circuit fault in the bridge arm of the second phase and the third phase of the three-phase buck converter 01, then there is a short circuit fault in the bridge arm of the first phase of the three-phase buck converter 01.

[0116] In addition, the controller controls the bridge arm switch 3 of the upper arm of the second phase to turn on, and controls the bridge arm switches 3 of the lower arm of the second phase, the upper arms of the first phase and the third phase, and the bridge arm switches 3 of the lower arms of the first phase and the third phase to turn off; the controller controls the bridge arm switch 3 of the upper arm of the third phase to turn on, and controls the bridge arm switches 3 of the lower arm of the third phase, the upper arms of the first phase and the second phase, and the bridge arm switches 3 of the lower arms of the first phase and the second phase to turn off; the controller controls the bridge arm switch 3 of the lower arm of the first phase to turn on, and controls the bridge arm switch 3 of the upper arm of the first phase, the upper arms of the second phase and the third phase, and the bridge arm switches 3 of the lower arms of the second phase and the third phase to turn off; the controller controls the bridge arm switch 3 of the lower arm of the second phase to turn on, and controls the bridge arm switch 3 of the upper arm of the second phase, the upper arms of the first phase and the third phase, and the bridge arm switches 3 of the lower arms of the first phase and the third phase to turn off; the controller controls the bridge arm switch 3 of the lower arm of the third phase to turn on, and controls the bridge arm switch 3 of the upper arm of the third phase, the upper arms of the first phase and the second phase, and the bridge arm switches 3 of the lower arms of the first phase and the second phase to turn off. The above five situations are similar to the judgment method of controlling the bridge arm switch 3 of the upper arm of the first phase to turn on and controlling the bridge arm switches 3 of the lower arm of the first phase, the upper arms of the second phase and the third phase, and the bridge arm switches 3 of the lower arms of the second phase and the third phase to turn off, which will not be elaborated here.

[0117] After determining that there is a short circuit fault in the bridge arm of the three-phase buck converter 01, the pre-charge switch 2 is disconnected, and a short circuit fault signal of the bridge arm is sent. The short circuit fault signal of the bridge arm can be a signal lamp, a prompt tone, etc.

[0118] In a possible implementation manner, the processing flow of the fault detection can be as Figure 6 shown, including the following steps:

[0119] 601. The controller controls each bridge arm switch 3 to turn on, and controls the pre-charge switch 2 to turn on.

[0120] 602. The controller obtains the sampling value of the voltage sampling circuit. When the sampling value of the voltage sampling circuit meets the specified conditions, it is determined that there is a short circuit fault at the output terminal 6 of the three-phase buck converter 01.

[0121] The specified condition may be that within a specified duration from when the sampled value of the voltage sampling circuit starts to increase from 0, the voltage increment of the sampled value collected relative to the previous sampled value is less than a second voltage increment threshold. The sampling frequency can be preset by a technician, for example, sampling once every 40 microseconds. The second voltage increment threshold can also be preset by a technician, such as 5 volts, 10 volts, etc. For example, within the specified duration from when the sampled value of the voltage sampling circuit starts to increase from 0, the previous sampled value is 200 volts, the sampled value collected by the voltage sampling circuit is 201 volts, and the voltage increment is 1 volt, which is less than the second voltage increment threshold of 5 volts. Therefore, the current sampled value of the voltage sampling circuit meets this specified condition. Alternatively, the specified condition is that after the sampled value of the voltage sampling circuit starts to increase from 0 for a specified duration, the sampled value collected is less than a second voltage threshold. The second voltage threshold can be preset by a technician, such as 200 volts, etc. For example, after the sampled value of the voltage sampling circuit starts to increase from 0 for a specified duration, the sampled value collected by the voltage sampling circuit is 201 volts, which is greater than the second voltage threshold of 200 volts. Therefore, the current sampled value of the voltage sampling circuit does not meet this specified condition. For example Figure 7 As shown, OAB is the voltage sampled value curve when a short - circuit fault occurs at the output terminal, and OCD is the voltage sampled value curve when no short - circuit fault occurs at the output terminal. OA and OC are within the specified duration from when the sampled value of the voltage sampling circuit starts to increase from 0. When the voltage increment of OA is less than the second voltage increment threshold, it may indicate that a short - circuit fault occurs at the output terminal. AB and CD are after the sampled value of the voltage sampling circuit starts to increase from 0 for the specified duration. When the sampled value of the voltage of AB is less than the second voltage threshold, it may indicate that a short - circuit fault occurs at the output terminal.

[0122] In the embodiments of the present disclosure, by the voltage sampled values in different states of the leg switches, it is determined whether a short - circuit fault occurs in the three - phase buck converter. In this way, the short - circuit fault of the three - phase buck converter can be detected in a timely manner, so as to solve the short - circuit fault in a timely manner and prevent power interruption.

[0123] All the above - mentioned alternative technical solutions can be combined arbitrarily to form alternative embodiments of the present disclosure, which will not be elaborated one by one here.

[0124] Based on the same technical concept, the embodiments of the present disclosure further provide a fault - detection device, as Figure 8 shown. The device includes:

[0125] A control module 810, configured to control each leg switch 3 to enter a specified state respectively and control the pre - charge switch 2 to be turned on. Specifically, it can implement the processing functions of the above - mentioned step 201 and other implicit steps.

[0126] An acquisition module 820, configured to acquire the sampled value of the voltage sampling circuit. Specifically, it can implement the processing functions of the above - mentioned step 202 and other implicit steps.

[0127] A determination module 830, configured to determine that a short - circuit fault has occurred when the sampling value of the voltage sampling circuit meets a specified condition. Specifically, it can implement the processing functions of step 203 above, as well as other implicit steps.

[0128] In a possible implementation, a control module 810 is configured to: control each leg switch 3 to be turned off. Specifically, it can implement the processing functions of step 301 above, as well as other implicit steps.

[0129] A determination module 830, configured to: determine that a leg short - circuit fault has occurred in the three - phase buck converter 01. Specifically, it can implement the processing functions of step 302 above, as well as other implicit steps.

[0130] In a possible implementation, a control module 810 is configured to: control the leg switch 3 of the first phase to be turned on, and control the leg switches 3 of the second and third phases to be turned off. Specifically, it can implement the processing functions of step 303 above, as well as other implicit steps.

[0131] A determination module 830, configured to: determine that a leg short - circuit fault has occurred in the second or third phase of the three - phase buck converter 01. Specifically, it can implement the processing functions of step 303 above, as well as other implicit steps.

[0132] In a possible implementation, a control module 810 is configured to: control the leg switch 3 of the upper leg of the first phase to be turned on, and control the leg switches 3 of the lower leg of the first phase, the upper legs of the second and third phases, and the lower legs of the second and third phases to be turned off. Specifically, it can implement the processing functions of step 503 above, as well as other implicit steps.

[0133] A determination module 830, configured to: determine that a leg short - circuit fault has occurred in the lower leg of the second or third phase of the three - phase buck converter 01. Specifically, it can implement the processing functions of step 504 above, as well as other implicit steps.

[0134] In a possible implementation, a control module 810 is configured to: control the leg switch 3 of the lower leg of the first phase to be turned on, and control the leg switches 3 of the upper leg of the first phase, the upper legs of the second and third phases, and the lower legs of the second and third phases to be turned off. Specifically, it can implement the processing functions of step 504 above, as well as other implicit steps.

[0135] A determination module 830, configured to: determine that a leg short - circuit fault has occurred in the upper leg of the second or third phase of the three - phase buck converter 01. Specifically, it can implement the processing functions of step 504 above, as well as other implicit steps.

[0136] In a possible implementation, the specified condition is that the voltage increment of the sampling value of the voltage sampling circuit relative to the previous sampling value is greater than the voltage increment threshold; or, the sampling value of the voltage sampling circuit is greater than the first voltage threshold. Specifically, it can implement the processing functions of step 802 above and other implicit steps.

[0137] In a possible implementation, the control module 810 is used to: control each leg switch 3 to be turned on. Specifically, it can implement the processing functions of step 801 above and other implicit steps.

[0138] The determination module 830 is used to: determine that a short-circuit fault occurs at the output terminal 6 of the three-phase buck converter 01. Specifically, it can implement the processing functions of step 302 above and other implicit steps.

[0139] In a possible implementation, the specified condition is that: within a specified time period when the sampling value of the voltage sampling circuit starts to increase from 0, the voltage increment of the sampled value relative to the previous sampled value is less than the second voltage increment threshold; or, after the sampling value of the voltage sampling circuit starts to increase for a specified time period from 0, the sampled value is less than the second voltage threshold. Specifically, it can implement the processing functions of step 602 above and other implicit steps.

[0140] In a possible implementation, the control module 810 is further used to: control the pre-charge switch 2 to be turned off. Specifically, it can implement the processing functions of step 303 above and other implicit steps.

[0141] The above control module 810, acquisition module 820, and determination module 830 can be implemented by a processor, or by a processor in cooperation with a memory and a display.

[0142] In the embodiments of the present disclosure, by using the voltage sampling values in different states of the leg switches, it is determined whether a short-circuit fault occurs in the three-phase buck converter. In this way, the short-circuit fault of the three-phase buck converter can be detected in a timely manner, so as to solve the short-circuit fault in a timely manner and prevent power interruption.

[0143] The embodiments of the present disclosure also provide a computer-readable storage medium. The computer-readable storage medium can be any available medium that can be stored by a computer device or a data storage device such as a data center including one or more available media. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid-state drive), etc. The computer-readable storage medium includes instructions that instruct a computing device to execute the method for fault detection.

[0144] In the description of this specification, the descriptions referring to the terms "certain embodiments", "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiments or examples are included in at least one embodiment or example of the present disclosure. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0145] It can be understood that "a plurality of" in the present disclosure means two or more, and other quantifiers are similar. "And / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the associated objects before and after. The singular forms of "a", "the", and "said" are also intended to include the plural forms unless the context clearly indicates otherwise.

[0146] It can be further understood that the terms "first", "second", etc. are used to describe various information, but this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other and do not represent a specific order or degree of importance. In fact, the expressions such as "first" and "second" can be used interchangeably. For example, without departing from the scope of the present disclosure, the first information can also be referred to as the second information, and similarly, the second information can also be referred to as the first information.

[0147] It can be further understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "front", "rear", "upper", "lower", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing this embodiment and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation.

[0148] It can be further understood that although the operations are described in a specific order in the drawings in the embodiments of the present disclosure, it should not be understood that they are required to be performed in the specific order shown or in a serial order, or that all the operations shown are required to obtain the desired result. In a specific environment, multitasking and parallel processing may be advantageous.

[0149] Other embodiments of the present disclosure will be readily apparent to those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. The present disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow the general principles of the present disclosure and include known or customary technical means in the technical field not disclosed herein. The specification and examples are only to be considered as exemplary, and the true scope and spirit of the present disclosure are pointed out by the scope of the claims.

[0150] It should be understood that the present disclosure is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is only limited by the appended claims.

Claims

1. A method for fault detection, characterized in that, The method is applied to a three-phase buck converter (01), which includes a controller, a pre-charge switch (2), multiple leg switches (3), and a voltage sampling circuit. The input terminal (5) of the three-phase buck converter (01) is electrically connected to an AC power supply, and the output terminal (6) of the three-phase buck converter (01) is electrically connected to an electrical device; The method includes: The controller controls each leg switch (3) to enter a specified state respectively, and controls the pre-charge switch (2) to be turned on; The controller obtains the sampling value of the voltage sampling circuit; When the sampling value of the voltage sampling circuit meets a specified condition, the controller determines that a short-circuit fault has occurred.

2. The method according to claim 1, wherein The controller controls each leg switch (3) to enter a specified state respectively, including: The controller controls each leg switch (3) to be turned off; The controller determines a short-circuit fault, including: The controller determines that a leg short-circuit fault has occurred in the three-phase buck converter (01).

3. The method according to claim 1, wherein The controller controls each leg switch (3) to enter a specified state respectively, including: The controller controls the leg switch (3) of the first phase to be turned on, and controls the leg switches (3) of the second and third phases to be turned off; The controller determines a short-circuit fault, including: The controller determines that a leg short-circuit fault has occurred in the second or third phase of the three-phase buck converter (01).

4. The method according to claim 1, characterized in that, The controller controls each leg switch (3) to enter a specified state respectively, including: The controller controls the leg switch (3) of the upper leg of the first phase to be turned on, and controls the leg switches (3) of the lower leg of the first phase, the upper legs of the second and third phases, and the lower legs of the second and third phases to be turned off; The controller determines a short-circuit fault, including: The controller determines that a leg short-circuit fault has occurred in the lower leg of the second or third phase of the three-phase buck converter (01).

5. The method according to any one of claims 1, characterized in that, The controller controls each leg switch (3) to enter a specified state respectively, including: The controller controls the leg switch (3) of the lower leg of the first phase to be turned on, and controls the leg switches (3) of the upper leg of the first phase, the upper legs of the second and third phases, and the lower legs of the second and third phases to be turned off; The controller determines a short-circuit fault, including: The controller determines that a leg short-circuit fault has occurred in the upper leg of the second or third phase of the three-phase buck converter (01).

6. The method according to any one of claims 3-5, characterized in that, The specified condition is that the voltage increment of the sampling value of the voltage sampling circuit relative to the previous sampling value is greater than a first voltage increment threshold; or, the sampling value of the voltage sampling circuit is greater than a first voltage threshold.

7. The method according to claim 1, wherein The controller controls each leg switch (3) to enter a specified state respectively, including: The controller controls each leg switch (3) to be turned on; The controller determines a short-circuit fault, including: The controller determines that a short-circuit fault has occurred at the output terminal (6) of the three-phase buck converter (01).

8. The method according to claim 7, wherein The specified condition is: Within a specified duration during which the sampled value of the voltage sampling circuit starts increasing from 0, the voltage increment of the sampled value collected relative to the previous sampled value is less than a second voltage increment threshold; or, After the sampled value of the voltage sampling circuit starts increasing for a specified duration from 0, the sampled value collected is less than a second voltage threshold.

9. The method according to claim 1, characterized in that After determining the short - circuit fault, the method further includes: The controller controls the pre - charge switch (2) to disconnect.

10. A device for fault detection, characterized in that, The device is applied to a three - phase buck converter (01), the three - phase buck converter (01) includes a controller, a pre - charge switch (2), a plurality of leg switches (3) and a voltage sampling circuit. The input terminal (5) of the three - phase buck converter (01) is electrically connected to an AC power supply, and the output terminal (6) of the three - phase buck converter (01) is electrically connected to an electrical device; The device includes: A control module, configured to control each leg switch (3) to enter a specified state respectively and control the pre - charge switch (2) to be turned on; An acquisition module, configured to acquire the sampled value of the voltage sampling circuit; A determination module, configured to when the sampled value of the voltage sampling circuit meets a specified condition, the controller determines that a short - circuit fault has occurred.

11. A computer device, characterized in that, The computer device includes a memory and a processor. The memory is used to store computer instructions; the processor executes the computer instructions stored in the memory so that the computer device executes the method according to any one of claims 1 - 9 above.

12. A computer-readable storage medium, characterized in that, The computer - readable storage medium stores computer program code. When the computer program code is executed by a computer device, the computer device executes the method according to any one of claims 1 - 9 above.

13. A computer program product, characterized in that, The computer program product includes computer program code. When the computer program code is executed by a computer device, the computer device executes the method according to any one of claims 1 - 9 above.

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