Three-phase input open-phase detection method and device and computer readable storage medium

Abstract

The invention discloses a three-phase input open-phase detection method, a three-phase open-phase detection device and a computer readable storage medium. The open-phase detection method comprises the following steps: based on a first phase voltage in three phases as a reference, obtaining a second phase voltage and a third phase voltage in the three phases; acquiring a voltage arithmetic sum based on the second phase voltage and the third phase voltage; and obtaining an open-phase result based on the second phase voltage, the third phase voltage and the voltage arithmetic sum. According to the open-phase detection method, the phase voltages of the other two phases with the same phase as the reference and the voltage arithmetic sum of the two phases are directly obtained, and the open-phase result of three-phase input is obtained based on the phase voltages of the two phases and the voltage arithmetic sum of the two phases, so that the detection efficiency of open-phase detection of the three-phase input can be improved; therefore, the probability of safety problems of the equipment is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of phase loss detection, and in particular to a three-phase input phase loss detection method, a three-phase phase loss detection device and a computer-readable storage medium. Background Art

[0002] At present, if static reactive generators, inverters and other equipment are not protected when the power input is missing a phase, the product or load equipment may be damaged. If static reactive generators and other power grid management equipment are not protected when there is a phase loss, it is more likely to cause compensation to go out of control, inject a large amount of unnecessary reactive power and harmonics, and cause damage to other equipment in the power grid. Therefore, input phase loss detection is very necessary for this type of product.

[0003] In traditional phase loss detection, most of them indirectly infer the phase loss of AC input voltage by detecting the size and change of DC bus voltage. A small part directly detects the AC three-phase voltage to determine the input voltage phase loss. However, they also obtain the three-phase voltage of the equipment for phase loss detection. The above phase loss detection method has low detection efficiency and is easy to cause safety problems of the equipment. Summary of the invention

[0004] In order to solve the above problems, the present application proposes a three-phase input phase loss detection method, a three-phase phase loss detection device and a computer-readable storage medium to improve the detection efficiency of three-phase input phase loss detection and reduce the probability of safety problems in the equipment.

[0005] In order to solve the above technical problems, a technical solution adopted in the present application is: to provide a three-phase input phase loss detection method, the phase loss detection method comprising: based on the first phase voltage of the three phases as a reference, obtaining the second phase voltage and the third phase voltage of the three phases; obtaining the voltage arithmetic sum based on the second phase voltage and the third phase voltage; obtaining the phase loss result based on the second phase voltage, the third phase voltage and the voltage arithmetic sum.

[0006] In some embodiments, the step of obtaining the phase loss result based on the second phase voltage, the third phase voltage and the voltage arithmetic sum includes: respectively obtaining the maximum and minimum values ​​of the second phase voltage, the third phase voltage and the voltage arithmetic sum within a preset period; obtaining the phase loss result based on the maximum and minimum values ​​of the second phase voltage, the maximum and minimum values ​​of the third phase voltage, and the maximum and minimum values ​​of the voltage arithmetic sum within the preset period.

[0007] In some embodiments, the step of obtaining the phase loss result based on the maximum and minimum values ​​of the second phase voltage, the maximum and minimum values ​​of the third phase voltage, and the maximum and minimum values ​​of the voltage arithmetic sum within a preset period includes: in response to the absolute value of the maximum value or the absolute value of the minimum value of the voltage arithmetic sum being less than or equal to the first voltage threshold, judging that the first phase is lost; in response to the absolute value of the maximum value or the absolute value of the minimum value of the second phase voltage being greater than the second voltage threshold, judging that the second phase is lost; in response to the absolute value of the maximum value or the absolute value of the minimum value of the third phase voltage being greater than the second voltage threshold, judging that the third phase is lost.

[0008] In some embodiments, the step of obtaining the phase loss result based on the maximum and minimum values ​​of the second phase voltage, the maximum and minimum values ​​of the third phase voltage, and the maximum and minimum values ​​of the voltage arithmetic sum within a preset period includes: in response to the absolute value of the maximum value or the absolute value of the minimum value of the voltage arithmetic sum being less than or equal to the first voltage threshold and the duration being greater than the preset time threshold, judging that the first phase is lost; in response to the absolute value of the maximum value or the absolute value of the minimum value of the second phase voltage being greater than the second voltage threshold and the duration being greater than the preset time threshold, judging that the second phase is lost; in response to the absolute value of the maximum value or the absolute value of the minimum value of the third phase voltage being greater than the second voltage threshold and the duration being greater than the preset time threshold, judging that the third phase is lost.

[0009] In some embodiments, the steps of respectively obtaining the maximum and minimum values ​​of the second phase voltage, the third phase voltage and the voltage arithmetic sum within a preset period include: obtaining a first instantaneous voltage value of the second phase voltage, a second instantaneous voltage value of the third phase voltage, and calculating the instantaneous voltage value arithmetic sum of the first instantaneous voltage value and the second instantaneous voltage value; performing timed sampling on the first instantaneous voltage value, the second instantaneous voltage value and the instantaneous voltage value arithmetic sum; comparing the first instantaneous voltage value within the preset period to obtain the maximum and minimum values ​​of the second phase voltage within the preset period, comparing the second instantaneous voltage value within the preset period to obtain the maximum and minimum values ​​of the third phase voltage within the preset period, and comparing the instantaneous voltage value arithmetic sum within the preset period to obtain the maximum and minimum values ​​of the voltage arithmetic sum.

[0010] In some embodiments, the step of obtaining a first instantaneous voltage value of the second phase voltage and a second instantaneous voltage value of the third phase voltage includes: obtaining an analog voltage value of the second phase voltage and an analog voltage value of the third phase voltage; and converting the analog voltage value of the second phase voltage and the analog voltage value of the third phase voltage into a first instantaneous voltage value of the second phase voltage and a second instantaneous voltage value of the third phase voltage based on a preset conversion relationship.

[0011] In order to solve the above technical problems, another technical solution adopted in the present application is: to provide a three-phase phase loss detection device, which includes a differential circuit and a processor, the differential circuit is used to obtain the second phase voltage and the third phase voltage in the three phases based on the first phase voltage in the three phases as a reference; the processor is connected to the differential circuit, and is used to execute the phase loss detection method implementing any of the above items.

[0012] In some embodiments, the three-phase phase loss detection device also includes a voltage conversion circuit, which is connected to the differential circuit and the processor, and is used to convert the analog voltage value of the second phase voltage and the analog voltage value of the third phase voltage into a first instantaneous voltage value of the second phase voltage and a second instantaneous voltage value of the third phase voltage based on a preset conversion relationship.

[0013] In some embodiments, the differential circuit includes a first comparison circuit and a second comparison circuit, the first input terminal of the first comparison circuit is connected to the first phase of the three phases, the second input terminal of the first comparison circuit is connected to the second phase of the three phases, and the output terminal of the first comparison circuit is used to output the second phase voltage; the first input terminal of the second comparison circuit is connected to the first phase of the three phases, the second input terminal of the second comparison circuit is connected to the third phase of the three phases, and the output terminal of the second comparison circuit is used to output the third phase voltage.

[0014] In order to solve the above technical problems, another technical solution adopted by the present application is: providing a computer-readable storage medium, which stores program instructions therein, and the program instructions are executed by a processor to implement any of the above-mentioned phase loss detection methods.

[0015] The beneficial effect of the present application is: different from the prior art, the phase loss detection method of the present application is based on the first phase voltage of the three phases as a reference, obtains the second phase voltage and the third phase voltage of the three phases, calculates the voltage arithmetic sum using the second phase voltage and the third phase voltage, and finally performs phase loss judgment using the second phase voltage, the third phase voltage and the voltage arithmetic sum to obtain the phase loss result. Through the above method, the present application directly obtains the phase voltage of the other two phases with the same phase as a reference and the arithmetic sum of the voltages of the two phases, and obtains the phase loss result of the three-phase input based on the phase voltage of the two phases and the voltage arithmetic of the two phases, which can improve the detection efficiency of the three-phase input phase loss detection, thereby reducing the probability of safety problems in the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the circuit diagram of the power part of the inverter;

[0017] Figure 2 It is a flow chart of an embodiment of a three-phase phase loss detection method of the present application;

[0018] Figure 3 yes Figure 2A flowchart of a specific embodiment of step S103;

[0019] Figure 4 yes Figure 3 Schematic diagram of the process of the first embodiment of step S202;

[0020] Figure 5 yes Figure 3 A schematic diagram of the flow chart of the second embodiment of step S202;

[0021] Figure 6 yes Figure 3 A schematic diagram of a flow chart of an embodiment of step S201;

[0022] Figure 7 yes Figure 6 A flow chart of an embodiment of step S501;

[0023] Figure 8 It is a structural schematic diagram of an embodiment of a three-phase phase loss detection device of the present application;

[0024] Fig. 9 is a structural diagram of an embodiment of a differential circuit of the present application;

[0025] Fig.10 is a circuit structure diagram of another embodiment of the differential circuit of the present application;

[0026] Fig.11 It is a structural diagram of an embodiment of a computer-readable storage medium of the present application. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0028] Current static VAR generators, inverters and other equipment may be damaged if they are not protected when the power input is missing a phase. Static VAR generators and other power grid management equipment, if not protected when a phase is missing, are more likely to cause compensation to get out of control, injecting a large amount of unnecessary reactive power and harmonics, causing damage to other equipment in the power grid.

[0029] The inverter input phase loss only exists in products with three-phase input. If one phase of the three-phase input R, S, T is disconnected, it is considered that the input phase loss has occurred. Figure 1 , Figure 1 This is the circuit diagram of the inverter power part. Figure 1As shown in the figure, if the inverter is still running with a phase loss at the input, capacitors C1 and C2 will be charged repeatedly and over a large range, which will inevitably damage capacitors C1 and C2, thereby causing damage to the entire inverter. If the load is light, although the capacitors will not be damaged, the ripple of the DC voltage will increase a lot compared to normal, which will cause the oscillation of the switch duty cycle and the oscillation of the load current. When the load is heavy, the rectifier bridge will be further damaged, increasing the probability of inverter failure, that is, phase loss will occur during power transmission, and the inverter will easily burn out due to single-phase high current operation. Therefore, for this type of product, input phase loss detection is very necessary.

[0030] In traditional phase loss detection, most of them indirectly infer the phase loss of AC input voltage by detecting the size and change of DC bus voltage. A small part directly detects the AC three-phase voltage to determine the input voltage phase loss. However, they also obtain the three-phase voltage of the equipment for phase loss detection. The above phase loss detection method has low detection efficiency and is easy to cause safety problems of the equipment.

[0031] In order to solve the above problems, this application first proposes a three-phase phase loss detection method, see Figure 2 , Figure 2 1 is a flow chart of an embodiment of a three-phase phase loss detection method of the present application. Figure 2 As shown, the three-phase phase loss detection method of this embodiment specifically includes steps S101 to S103:

[0032] Step S101: based on the first phase voltage among the three phases as a reference, obtain the second phase voltage and the third phase voltage among the three phases.

[0033] The three-phase loss detection device can directly obtain the phase voltage of two phases among the three phases of the equipment to perform phase loss detection on the three-phase input.

[0034] In this embodiment, the three-phase phase loss detection device can obtain the second phase voltage and the third phase voltage among the three phases based on the first phase voltage among the three phases as a reference. For example, the three-phase phase loss detection device can use a differential circuit to take the R phase among the three phases as a reference point to obtain the second phase voltage V_RS and the third phase voltage V_RT among the three phases.

[0035] Step S102: Obtaining a voltage arithmetic sum based on the second phase voltage and the third phase voltage.

[0036] The three-phase phase loss detection device obtains the second phase voltage and the third phase voltage in the three phases, and can calculate the second phase voltage and the third phase voltage based on the two to obtain the voltage arithmetic sum. As mentioned above, if the obtained second phase voltage is V_RS and the obtained third phase voltage is V_RT, the voltage arithmetic sum SumRsRt of the two can be calculated.

[0037] Step S103: Obtaining a phase loss result based on the second phase voltage, the third phase voltage and the voltage arithmetic sum.

[0038] After the three-phase phase loss detection device obtains the second phase voltage, the third phase voltage and the voltage arithmetic sum, it can obtain the phase loss result based on the second phase voltage, the third phase voltage and the voltage arithmetic sum.

[0039] For example, the three-phase phase loss detection device can collect the second phase voltage V_RS and the third phase voltage V_RT at preset time intervals, and calculate the voltage arithmetic sum SumRsRt of the two at the current moment. At this time, the three-phase phase loss detection device can obtain the maximum and minimum values ​​of the second phase voltage V_RS, the maximum and minimum values ​​of the third phase voltage V_RT and the voltage arithmetic sum SumRsRt within the preset period.

[0040] Based on the maximum and minimum values ​​of the second phase voltage V_RS, the maximum and minimum values ​​of the third phase voltage V_RT and the voltage arithmetic sum SumRsRt within the preset period, the three-phase phase loss detection device can detect the phase loss result in the three-phase input. The specific determination method is described below and will not be repeated here.

[0041] Different from the prior art, the phase loss detection method of the present application is based on the first phase voltage of the three phases as a reference, obtains the second phase voltage and the third phase voltage of the three phases, calculates the voltage arithmetic sum using the second phase voltage and the third phase voltage, and finally performs phase loss judgment using the second phase voltage, the third phase voltage and the voltage arithmetic sum to obtain the phase loss result. Through the above method, the present application directly obtains the phase voltage of the other two phases with the same phase as a reference and the arithmetic sum of the voltages of the two phases, and obtains the phase loss result of the three-phase input based on the phase voltage of the two phases and the voltage arithmetic of the two phases, which can improve the detection efficiency of the three-phase input phase loss detection, thereby reducing the probability of safety problems in the equipment.

[0042] Optionally, a method for obtaining a phase loss result based on the second phase voltage, the third phase voltage, and voltage arithmetic is as follows: Figure 3 See Figure 3 , Figure 3 yes Figure 2 Schematic diagram of a specific embodiment of step S103 in FIG. Figure 3 The method shown implements step 103, and the specific implementation steps include step S201 to step S202:

[0043] Step S201: respectively obtaining the maximum value and the minimum value of the second phase voltage, the third phase voltage and the voltage arithmetic sum within a preset period.

[0044] As mentioned above, the three-phase phase loss detection device can perform regular acquisition of the second phase voltage and the third phase voltage, and calculate the voltage arithmetic sum of the two at the regular acquisition time and store them. After a period of time, the maximum and minimum values ​​of the second phase voltage, the third phase voltage and the voltage arithmetic sum within the preset period can be obtained respectively. Among them, the time of regular acquisition and the preset period can be set based on actual conditions and are not limited here.

[0045] In an application scenario, the three-phase phase loss detection device can collect the second phase voltage and the third phase voltage at regular intervals of 2 ms, and calculate the voltage arithmetic sum of the two. When obtaining the maximum and minimum values ​​of the second phase voltage, the third phase voltage and the voltage arithmetic sum within a preset period, the preset period can be set to 30 ms. At this time, three arrays gVRS

[15] , gVRT

[15] , and gSumRsRt

[15] with a length of 15 can be set to record the second phase voltage V_RS, the third phase voltage V_RT and the voltage arithmetic sum SumRsRt of the two 30 ms before the current moment through sliding window shifting. When the three-phase phase loss detection device obtains the second phase voltage V_RS and the third phase voltage V_RT at a new moment, the sliding window is moved to save the second phase voltage V_RS and the third phase voltage V_RT and the voltage arithmetic sum SumRsRt of the two at this moment, and the data stored in the array earliest is deleted.

[0046] At this time, the voltage data stored in the array can be compared to obtain the maximum and minimum values ​​of the second phase voltage V_RS, the third phase voltage V_RT, and the voltage arithmetic sum SumRsRt within a preset period.

[0047] Step S202: Obtaining a phase loss result based on the maximum and minimum values ​​of the second phase voltage, the maximum and minimum values ​​of the third phase voltage, and the maximum and minimum values ​​of the voltage arithmetic sum within a preset period.

[0048] After obtaining the maximum and minimum values ​​of the second phase voltage, the maximum and minimum values ​​of the third phase voltage, and the maximum and minimum values ​​of the voltage arithmetic sum within a preset period, the three-phase phase loss detection device can compare the maximum and minimum values ​​of the second phase voltage, the maximum and minimum values ​​of the third phase voltage, and the maximum and minimum values ​​of the voltage arithmetic sum within the preset period with the preset voltage threshold values, respectively, obtain the comparison result and thus determine the phase loss result. The specific judgment process is described as follows.

[0049] Optionally, the method for obtaining the phase loss result based on the maximum and minimum values ​​of the second phase voltage, the maximum and minimum values ​​of the third phase voltage, and the maximum and minimum values ​​of the voltage arithmetic sum within a preset period is as follows: Figure 4 See Figure 4 , Figure 4 yes Figure 3Schematic diagram of the flow chart of the first embodiment of step S202 in FIG. Figure 4 The method shown implements step 202, and the specific implementation steps include steps S301 to S303:

[0050] Step S301: In response to the absolute value of the maximum value or the absolute value of the minimum value of the voltage arithmetic sum being less than or equal to the first voltage threshold, it is determined that the first phase is missing.

[0051] In this embodiment, the second phase voltage is V_RS, the third phase voltage is V_RT, and the voltage arithmetic sum of the two is SumRsRt as an example. When the three-phase phase loss detection device obtains the voltage arithmetic sum SumRsRt within the preset period, the voltage arithmetic sum maximum value gSumRsRtMax and the minimum value gSumRsRtMin are respectively determined whether the absolute value of the voltage arithmetic sum maximum value gSumRsRtMax and the absolute value of the minimum value gSumRsRtMin are less than or equal to the first voltage threshold. When one of the absolute value of the voltage arithmetic sum maximum value gSumRsRtMax and the absolute value of the minimum value gSumRsRtMin is less than the first preset threshold, it is determined that the first phase R phase is phase lost. In this embodiment, the first preset threshold can be set to 90V. In theory, the amplitude of the first preset threshold should be set to 0V, but in the actual power supply process, in order to avoid interference, the first preset threshold can be set to 90V in this embodiment. In other embodiments, the value of the first preset threshold can be set based on actual conditions, which is not limited here.

[0052] Step S302: In response to the absolute value of the maximum value or the absolute value of the minimum value of the second phase voltage being greater than the second voltage threshold, it is determined that the second phase is missing.

[0053] When the three-phase phase loss detection device obtains the absolute value gVRSmax of the maximum value and the absolute value gVRSmin of the minimum value of the second phase voltage V_RS within the preset period, it is judged whether the absolute value gVRSmax of the maximum value and the absolute value gVRSmin of the minimum value of the second phase voltage V_RS are greater than the second voltage threshold, and when one of them is greater than the second preset threshold, it is judged that the second phase S phase is phase lost. In this embodiment, the second preset threshold can be set to 107V. In other embodiments, the value of the second preset threshold can be set based on actual conditions, and is not limited here.

[0054] Step S303: In response to the absolute value of the maximum value or the absolute value of the minimum value of the third phase voltage being greater than the second voltage threshold, it is determined that the third phase is missing.

[0055] Similarly, when the three-phase phase loss detection device obtains the absolute value gVRTmax of the maximum value and the absolute value gVRTmin of the minimum value of the third phase voltage V_RT within a preset period, it respectively determines whether the absolute value gVRTmax of the maximum value and the absolute value gVRTmin of the minimum value of the third phase voltage V_RT are greater than the second voltage threshold. When one of them is greater than the second preset threshold, it is determined that the third phase T is phase lost.

[0056] In this embodiment, when performing phase loss detection on each phase of the three-phase input, the maximum and minimum values ​​of the voltage value within a preset period are used. When making a phase loss judgment, only one of the maximum and minimum values ​​of the voltage value needs to meet the conditions to determine that the phase is lost, thereby improving the efficiency of phase loss detection and reducing the probability of safety problems in the equipment.

[0057] Optionally, the method for obtaining the phase loss result based on the maximum and minimum values ​​of the second phase voltage, the maximum and minimum values ​​of the third phase voltage, and the maximum and minimum values ​​of the voltage arithmetic sum within a preset period is as follows: Figure 5 See Figure 5 , Figure 5 yes Figure 3 Schematic diagram of the flow chart of the second embodiment of step S202 in FIG. Figure 5 The method shown implements step 202, and the specific implementation steps include steps S401 to S403:

[0058] Step S401: In response to the absolute value of the maximum value or the absolute value of the minimum value of the voltage arithmetic sum being less than or equal to the first voltage threshold and the duration being greater than a preset time threshold, it is determined that the first phase is missing.

[0059] Step S401 is substantially the same as step S301, but is different from step S301 in that when one of the absolute value of the maximum value gSumRsRtMax and the absolute value of the minimum value gSumRsRtMin of the voltage arithmetic sum obtained by the three-phase phase loss detection device is less than or equal to the first voltage threshold, timing starts at this time. In the subsequent phase loss detection process, if one of the absolute value of the maximum value gSumRsRtMax and the absolute value of the minimum value gSumRsRtMin of the voltage arithmetic sum obtained by the three-phase phase loss detection device is less than or equal to the first voltage threshold and the duration is greater than the preset time threshold, the three-phase phase loss detection device determines that the first phase R phase is lost when the above conditions are met.

[0060] Step S402: In response to the absolute value of the maximum value or the absolute value of the minimum value of the second phase voltage being greater than the second voltage threshold and the duration being greater than a preset time threshold, it is determined that the second phase is missing.

[0061] Similarly, step S402 is substantially the same as step S302, except that, when one of the absolute value gVRSmax of the maximum value and the absolute value gVRSmin of the minimum value of the second phase voltage V_RS obtained by the three-phase phase loss detection device is greater than the second voltage threshold, timing starts at this time. In the subsequent phase loss detection process, if one of the absolute value gVRSmax of the maximum value and the absolute value gVRSmin of the minimum value of the second phase voltage V_RS obtained by the three-phase phase loss detection device is greater than the second voltage threshold and the duration is greater than the preset time threshold, the three-phase phase loss detection device determines that the second phase S is phase lost.

[0062] Step S403: In response to the absolute value of the maximum value or the absolute value of the minimum value of the third phase voltage being greater than the second voltage threshold and the duration being greater than the preset time threshold, it is determined that the third phase is missing.

[0063] Similarly, step S403 is substantially the same as step S303, except that, when one of the absolute value gVRTmax of the maximum value and the absolute value gVRTmin of the minimum value of the third phase voltage V_RT obtained by the three-phase phase loss detection device is greater than the second voltage threshold, timing starts at this time. In the subsequent phase loss detection process, if one of the absolute value gVRTmax of the maximum value and the absolute value gVRTmin of the minimum value of the third phase voltage V_RT obtained by the three-phase phase loss detection device is greater than the second voltage threshold and the duration is greater than the preset time threshold, the three-phase phase loss detection device determines that the third phase T is phase lost.

[0064] Among them, in this embodiment, in the above-mentioned phase loss judgment process, the preset time threshold can be set to 500ms. The purpose of setting the preset time threshold is to improve the anti-interference ability of the three-phase phase loss detection device and reduce the possibility of false alarms in the three-phase phase loss detection device. In other embodiments, the preset time threshold can also be set to other values ​​based on actual conditions, which is not limited here.

[0065] Optionally, the method for respectively obtaining the maximum and minimum values ​​of the second phase voltage, the third phase voltage and the voltage arithmetic sum within a preset period is as follows: Figure 6 See Figure 6 , Figure 6 yes Figure 3 Schematic diagram of the process of step S201 in an embodiment. This embodiment can be performed as follows Figure 6 The method shown implements step 201, and the specific implementation steps include steps S501 to S503:

[0066] Step S501: obtaining a first instantaneous voltage value of the second phase voltage and a second instantaneous voltage value of the third phase voltage, and calculating an arithmetic sum of the instantaneous voltage values ​​of the first instantaneous voltage value and the second instantaneous voltage value.

[0067] In this embodiment, the three-phase phase loss detection device can use a differential circuit to obtain the first instantaneous voltage value of the second phase voltage and the second instantaneous voltage value of the third phase voltage, and calculate the arithmetic sum of the instantaneous voltage values ​​of the first instantaneous voltage value and the second instantaneous voltage value.

[0068] Take the second phase voltage as V_RS, the third phase voltage as V_RT and the voltage arithmetic sum of the two as SumRsRt as an example. Wherein, the differential circuit includes a first comparison circuit and a second comparison circuit, the voltage signal of the first phase S phase is input to the first input end of the first comparison circuit and the first input end of the second comparison circuit, and then the voltage signal of the second phase S phase and the voltage signal of the third phase T phase are respectively input to the second input end of the first comparison circuit and the second input end of the second comparison circuit, and the first instantaneous voltage value of the second phase voltage and the second instantaneous voltage value of the third phase voltage can be obtained at the output end of the first comparison circuit and the output end of the second comparison circuit, and the arithmetic sum of the instantaneous voltage values ​​can be obtained based on the instantaneous voltage values ​​of the two.

[0069] Step S502: performing timed sampling on the first instantaneous voltage value, the second instantaneous voltage value and the arithmetic sum of the instantaneous voltage values.

[0070] At this time, as described above, the three-phase phase loss detection device can perform timed sampling on the first instantaneous voltage value, the second instantaneous voltage value output by the differential circuit, and the arithmetic sum of the instantaneous voltage values ​​calculated based on the two, and store them in the corresponding array.

[0071] Step S503: compare the first instantaneous voltage value within the preset period to obtain the maximum value and the minimum value of the second phase voltage within the preset period, compare the second instantaneous voltage value within the preset period to obtain the maximum value and the minimum value of the third phase voltage within the preset period, and compare the arithmetic sum of the instantaneous voltage values ​​within the preset period to obtain the maximum value and the minimum value of the voltage arithmetic sum.

[0072] At this time, the three-phase phase loss detection device can compare the first instantaneous voltage value in the array within the preset period to obtain the maximum value and minimum value of the second phase voltage within the preset period; compare the second instantaneous voltage value in the array within the preset period to obtain the maximum value and minimum value of the third phase voltage within the preset period, and compare the arithmetic sum of the instantaneous voltage values ​​in the array within the preset period to obtain the maximum value and minimum value of the voltage arithmetic sum.

[0073] Optionally, the method for obtaining the first instantaneous voltage value of the second phase voltage and the second instantaneous voltage value of the third phase voltage is as follows: Figure 7 See Figure 7 , Figure 7 yes Figure 6 Schematic diagram of the process of step S501 in an embodiment. This embodiment can be performed as follows Figure 7The method shown implements the step of obtaining the first instantaneous voltage value of the second phase voltage and the second instantaneous voltage value of the third phase voltage in step 501, and the specific implementation steps include steps S601 to S602:

[0074] Step S601: Acquire the analog voltage value of the second phase voltage and the analog voltage value of the third phase voltage.

[0075] In this embodiment, the second phase voltage and the third phase voltage obtained by the differential circuit are analog voltage values, and their amplitude range is 0 to 3.3 V. At this time, the analog voltage values ​​of the second phase voltage and the third phase voltage need to be converted before the phase failure judgment is performed.

[0076] Step S602: converting the analog voltage value of the second phase voltage and the analog voltage value of the third phase voltage into a first instantaneous voltage value of the second phase voltage and a second instantaneous voltage value of the third phase voltage based on a preset conversion relationship.

[0077] In this embodiment, the three-phase phase loss detection device can use a voltage conversion circuit to convert the analog voltage value of the second phase voltage and the analog voltage value of the third phase voltage into the first instantaneous voltage value of the second phase voltage and the second instantaneous voltage value of the third phase voltage based on a preset conversion relationship.

[0078] In this embodiment, the amplitude range of the converted instantaneous voltage value is -1000V to 1000V. In other embodiments, the conversion relationship can be set based on actual conditions and is not limited here.

[0079] Different from the prior art, the phase loss detection method of the present application is based on the first phase voltage of the three phases as a reference, obtains the second phase voltage and the third phase voltage of the three phases, calculates the voltage arithmetic sum using the second phase voltage and the third phase voltage, and finally performs phase loss judgment using the second phase voltage, the third phase voltage and the voltage arithmetic sum to obtain the phase loss result. In the above manner, the present application directly obtains the phase voltage of the other two phases with the same phase as a reference and the arithmetic sum of the two voltages, and obtains the phase loss result of the three-phase input based on the phase voltage of the two phases and the voltage arithmetic of the two phases, which can improve the detection efficiency of the three-phase input phase loss detection, thereby reducing the probability of safety problems in the equipment. In a further embodiment, the present application also sets a preset time threshold in the process of phase loss judgment. The purpose of setting the preset time threshold is to improve the anti-interference ability of the three-phase phase loss detection device and reduce the possibility of false alarms in the three-phase phase loss detection device.

[0080] Optionally, the present application further proposes a three-phase phase loss detection device, see Figure 8 , Figure 8 Schematic diagram of the structure of an embodiment of the three-phase phase loss detection device of the present application. Figure 8As shown, the three-phase phase loss detection device 100 of this embodiment includes a differential circuit 10 and a processor 20 .

[0081] Among them, the differential circuit 10 is used to obtain the second phase voltage and the third phase voltage among the three phases based on the first phase voltage among the three phases as a reference; the processor 20 is connected to the differential circuit 10, and is used to execute the phase loss detection method that implements any of the above items.

[0082] Alternatively, if Figure 8 As shown, the three-phase phase loss detection device 100 of this embodiment also includes a voltage conversion circuit 30, which is connected to the differential circuit 10 and the processor 20, and is used to convert the analog voltage value of the second phase voltage and the analog voltage value of the third phase voltage into a first instantaneous voltage value of the second phase voltage and a second instantaneous voltage value of the third phase voltage based on a preset conversion relationship.

[0083] Optionally, see Fig. 9 and Fig.10 , Fig. 9 It is a structural diagram of an embodiment of a differential circuit of the present application. Fig.10 FIG. 1 is a circuit diagram of another embodiment of the differential circuit of the present application. Fig. 9 and Fig.10 As shown, the differential circuit 10 includes a first comparison circuit 101 and a second comparison circuit 102, wherein the first input terminal of the first comparison circuit 101 is connected to the first phase R of the three phases, the second input terminal of the first comparison circuit 101 is connected to the second phase S of the three phases, and the output terminal of the first comparison circuit 101 is used to output the second phase voltage V_RS; the first input terminal of the second comparison circuit 102 is connected to the first phase R of the three phases, the second input terminal of the second comparison circuit 102 is connected to the third phase T of the three phases, and the output terminal of the second comparison circuit 102 is used to output the third phase voltage V_RT.

[0084] in, Fig.10 FIG. 1 is a schematic diagram of a specific circuit connection structure of an embodiment of a differential circuit, and its circuit connection relationship is as follows: Fig.10 As shown, no detailed description is given here. In other embodiments, other circuit structures can also be used to obtain the second phase voltage and the third phase circuit. It is only necessary for the circuit structure to meet the above functions and no limitation is made here.

[0085] Optionally, the present application further proposes a computer-readable storage medium. Fig.11 , Fig.11 It is a structural diagram of an embodiment of a computer-readable storage medium of the present application.

[0086] The computer-readable storage medium 200 of the embodiment of the present application stores program instructions 210 therein, and the program instructions 210 are executed by a processor to implement the three-phase phase loss detection method of any of the above embodiments.

[0087] Among them, the program instructions 210 can form a program file and be stored in the above-mentioned storage medium in the form of a software product, so that an electronic device (which can be a personal computer, a server, or a network device, etc.) or a processor (processor) executes all or part of the steps of each implementation method of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes, or terminal devices such as computers, servers, mobile phones, tablets, etc.

[0088] The computer-readable storage medium 200 of this embodiment may be, but is not limited to, a USB flash drive, an SD card, a PD optical drive, a mobile hard disk, a large-capacity floppy drive, a flash memory, a multimedia memory card, a server, and the like.

[0089] In one embodiment, a computer program product or computer program is provided, the computer program product or computer program includes computer instructions, the computer instructions are stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the electronic device performs the steps in the above-mentioned method embodiments.

[0090] In addition, if the above functions are implemented in the form of software functions and sold or used as independent products, they can be stored in a storage medium readable by a mobile terminal, that is, the present application also provides a storage device storing program data, the program data can be executed to implement the method of the above embodiment, and the storage device can be, for example, a USB flash drive, an optical disk, a server, etc. In other words, the present application can be embodied in the form of a software product, which includes a number of instructions for enabling a smart terminal to execute all or part of the steps of the method described in each embodiment.

[0091] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0092] Any process or method description in a flowchart or otherwise described herein may be understood to represent a mechanism, segment or portion of a code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0093] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (which can be a personal computer, server, network device or other system that can fetch instructions from the instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0094] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A three-phase input phase loss detection method, characterized in that: include: Based on the first phase voltage of the three phases as a reference, obtaining the second phase voltage and the third phase voltage of the three phases; acquiring a voltage arithmetic sum based on the second phase voltage and the third phase voltage; A phase loss result is obtained based on the second phase voltage, the third phase voltage and the voltage arithmetic sum.

2. The phase loss detection method according to claim 1, characterized in that: The step of obtaining the phase loss result based on the second phase voltage, the third phase voltage and the voltage arithmetic sum comprises: Respectively obtaining the maximum value and the minimum value of the second phase voltage, the third phase voltage and the voltage arithmetic sum within a preset period; The phase loss result is obtained based on the maximum value and the minimum value of the second phase voltage, the maximum value and the minimum value of the third phase voltage, and the maximum value and the minimum value of the voltage arithmetic sum within the preset period.

3. The phase loss detection method according to claim 2, characterized in that: The step of obtaining the phase loss result based on the maximum value and the minimum value of the second phase voltage, the maximum value and the minimum value of the third phase voltage, and the maximum value and the minimum value of the voltage arithmetic sum within the preset period includes: In response to an absolute value of the maximum value or the absolute value of the minimum value of the voltage arithmetic sum being less than or equal to a first voltage threshold, determining that the first phase is missing; In response to an absolute value of a maximum value or an absolute value of a minimum value of the second phase voltage being greater than a second voltage threshold, determining that the second phase is missing; In response to an absolute value of the maximum value or the absolute value of the minimum value of the third phase voltage being greater than a second voltage threshold, it is determined that the third phase is missing.

4. The method for detecting phase loss according to claim 2, characterized in that: The step of obtaining the phase loss result based on the maximum value and the minimum value of the second phase voltage, the maximum value and the minimum value of the third phase voltage, and the maximum value and the minimum value of the voltage arithmetic sum within a preset period includes: In response to the absolute value of the maximum value or the absolute value of the minimum value of the voltage arithmetic sum being less than or equal to the first voltage threshold and the duration being greater than a preset time threshold, determining that the first phase is missing; In response to an absolute value of a maximum value or an absolute value of a minimum value of the second phase voltage being greater than a second voltage threshold and a duration being greater than a preset time threshold, determining that the second phase is missing; In response to the absolute value of the maximum value or the absolute value of the minimum value of the third phase voltage being greater than the second voltage threshold and the duration being greater than the preset time threshold, it is determined that the third phase is missing.

5. The method for detecting phase loss according to claim 2, characterized in that: The step of respectively obtaining the maximum value and the minimum value of the second phase voltage, the third phase voltage and the voltage arithmetic sum within a preset period includes: Acquire a first instantaneous voltage value of the second phase voltage and a second instantaneous voltage value of the third phase voltage, and calculate an arithmetic sum of the instantaneous voltage values ​​of the first instantaneous voltage value and the second instantaneous voltage value; performing timed sampling on the first instantaneous voltage value, the second instantaneous voltage value and the arithmetic sum of the instantaneous voltage values; The first instantaneous voltage values ​​within the preset period are compared to obtain the maximum value and the minimum value of the second phase voltage within the preset period, the second instantaneous voltage values ​​within the preset period are compared to obtain the maximum value and the minimum value of the third phase voltage within the preset period, and the arithmetic sums of the instantaneous voltage values ​​within the preset period are compared to obtain the maximum value and the minimum value of the voltage arithmetic sum.

6. The phase loss detection method according to claim 5, characterized in that: The step of obtaining the first instantaneous voltage value of the second phase voltage and the second instantaneous voltage value of the third phase voltage comprises: Acquire an analog voltage value of the second phase voltage and an analog voltage value of the third phase voltage; The analog voltage value of the second phase voltage and the analog voltage value of the third phase voltage are converted into a first instantaneous voltage value of the second phase voltage and a second instantaneous voltage value of the third phase voltage based on a preset conversion relationship.

7. A three-phase phase loss detection device, characterized in that: include: A differential circuit, the differential circuit is used to obtain the second phase voltage and the third phase voltage of the three phases based on the first phase voltage of the three phases as a reference; A processor is connected to the differential circuit and is used to execute the phase loss detection method described in any one of claims 1 to 6.

8. The three-phase missing phase detection device according to claim 7, characterized in that: Also includes: A voltage conversion circuit is connected to the differential circuit and the processor, and is used to convert the analog voltage value of the second phase voltage and the analog voltage value of the third phase voltage into a first instantaneous voltage value of the second phase voltage and a second instantaneous voltage value of the third phase voltage based on a preset conversion relationship.

9. The three-phase missing phase detection device according to claim 7, characterized in that: The differential circuit includes a first comparison circuit and a second comparison circuit, wherein the first input end of the first comparison circuit is connected to the first phase of the three phases, the second input end of the first comparison circuit is connected to the second phase of the three phases, and the output end of the first comparison circuit is used to output the second phase voltage; the first input end of the second comparison circuit is connected to the first phase of the three phases, the second input end of the second comparison circuit is connected to the third phase of the three phases, and the output end of the second comparison circuit is used to output the third phase voltage.

10. A computer-readable storage medium, characterized in that: Program instructions are stored therein, and the program instructions are executed by a processor to implement the phase loss detection method described in any one of claims 1 to 6.

Images