Open-phase detection circuit and method, controller and air conditioner

Abstract

The embodiment of the invention relates to the technical field of open-phase detection, and discloses an open-phase detection circuit and method, a controller and an air conditioner. The open-phase detection circuit comprises a first voltage difference detection circuit connected with an R phase and an S phase of three-phase power and used for detecting a first voltage difference between the R phase and the S phase; the second voltage difference detection circuit is connected with the S phase and the T phase of the three-phase power and used for detecting the second voltage difference between the S phase and the T phase, the controller can determine the open-phase fault based on the level of the first voltage difference and the second voltage difference and the level overturning condition, and the detection circuit is simple in structure, low in production cost and high in practicability. And the open-phase fault conditions of the R phase, the S phase and the T phase of the three-phase power can be judged.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of phase loss detection, and in particular to a phase loss detection circuit and method, a controller, and an air conditioner. Background Art

[0002] In the field of high power, it is often necessary to detect whether the three-phase power connected to the electrical equipment has connection faults such as mismatch or phase loss, and then repair the fault in time to protect the electrical load using three-phase power. For example, in an air conditioner, the internal space is usually small, and the strong and weak currents are often complicated. At present, the traditional and relatively simple three-phase power detection circuit uses two wires to input into the single-chip microcomputer for detection, and the three-phase power mismatch and phase loss judgment is realized by detecting the voltage difference between the R phase and the S phase and the S phase and the T phase.

[0003] In the process of implementing the embodiments of the present invention, the inventors discovered that there is a problem in the above-mentioned related technologies. When there is a load in the air-conditioning system that supplies power to the neutral line, if the T-phase power line is broken and a phase loss fault occurs, the S-phase power line will be directly connected to the neutral line terminal through the load connected to the T-phase. This will cause the voltage difference between the S-phase and the T-phase to still be detected by the single-chip microcomputer, thereby failing to determine whether this type of T-phase power line fault occurs. Summary of the invention

[0004] Embodiments of the present application provide a phase loss detection circuit and method, a controller, and an air conditioner.

[0005] The purpose of the embodiment of the present invention is achieved through the following technical solutions:

[0006] To solve the above technical problems, in the first aspect, a phase loss detection circuit is provided in an embodiment of the present invention, including: a first voltage difference detection circuit, whose input end is connected to the R phase and the S phase of the three-phase electricity, for detecting the first voltage difference between the R phase and the S phase; a second voltage difference detection circuit, whose input end is connected to the S phase and the T phase of the three-phase electricity, for detecting the second voltage difference between the S phase and the T phase; a controller, whose input end is connected to the first voltage difference detection circuit and the second voltage difference detection circuit, and is configured to determine a phase loss fault based on the level and level flipping of the first voltage difference and the second voltage difference; wherein the R phase or the S phase of the three-phase electricity is connected to the live wire of the load, and the load is powered by the neutral wire.

[0007] In some embodiments, the first voltage difference detection circuit includes: a first conducting diode, whose anode is connected to the R phase of the three-phase electricity; a first optocoupler, which includes a first light-emitting diode and a first phototransistor, the anode of the first light-emitting diode is connected to the cathode of the first conducting diode, the cathode of the first light-emitting diode is connected to the S phase of the three-phase electricity, and the emitter of the first phototransistor is used to output the first voltage difference.

[0008] In some embodiments, the first phototransistor is an NPN-type transistor, and a collector of the first phototransistor is connected to a power supply.

[0009] In some embodiments, the first voltage difference detection circuit also includes: a first current limiting resistor, one end of which is connected to the cathode of the first conductive diode; a second current limiting resistor, one end of which is connected to the other end of the first current limiting resistor, and the other end of which is connected to the anode of the first light-emitting diode; a third conductive diode, an anode of which is connected to the cathode of the first light-emitting diode, and a cathode of which is connected to the anode of the first light-emitting diode; an electrolytic capacitor, an anode of which is connected to the collector of the first phototransistor, and a cathode of which is grounded.

[0010] In some embodiments, the second voltage difference detection circuit includes: a second conducting diode, whose cathode is connected to the T phase of the three-phase electricity; a second optocoupler, which includes a second light-emitting diode and a second phototransistor, the cathode of the second light-emitting diode is connected to the anode of the second conducting diode, the anode of the second light-emitting diode is connected to the S phase of the three-phase electricity, and the emitter of the second phototransistor is used to output the second voltage difference.

[0011] In some embodiments, the second phototransistor is an NPN-type transistor, and a collector of the second phototransistor is connected to a power supply.

[0012] In some embodiments, the second voltage difference detection circuit also includes: a third current limiting resistor, one end of which is connected to the anode of the second conductive diode; a fourth current limiting resistor, one end of which is connected to the other end of the third current limiting resistor, and the other end of which is connected to the cathode of the second light-emitting diode; a fourth conductive diode, an anode of which is connected to the cathode of the second light-emitting diode, and a cathode of which is connected to the anode of the second light-emitting diode.

[0013] To solve the above technical problems, in the second aspect, a phase loss detection method is provided in an embodiment of the present invention, and the method includes: obtaining a first voltage difference between the R phase and the S phase, and a second voltage difference between the S phase and the T phase through the phase loss detection circuit described in the first aspect; when the first voltage difference remains at a high level and no level flip occurs, determining that there is a phase loss fault in the R phase; when the first voltage difference and the second voltage difference flip in level, determining that there is a phase loss fault in the S phase; when the second voltage difference remains at a high level and no level flip occurs, determining that there is a phase loss fault in the T phase.

[0014] To solve the above technical problems, in the third aspect, an embodiment of the present invention provides a controller, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method described in the second aspect above.

[0015] To solve the above technical problems, in a fourth aspect, an embodiment of the present invention provides an air conditioner, comprising: a load, which supplies power to a neutral line, and a live line of the load is connected to an R phase or an S phase of three-phase electricity; and a phase loss detection circuit as described in the first aspect, wherein the phase loss detection circuit is connected to the R phase, the S phase, and the T phase of the three-phase electricity.

[0016] Compared with the prior art, the beneficial effects of the present invention are: different from the prior art, an embodiment of the present invention provides a phase loss detection circuit and method, a controller, and an air conditioner. The phase loss detection circuit includes a first voltage difference detection circuit connected to the R phase and the S phase of the three-phase electricity and used to detect a first voltage difference between the R phase and the S phase, a second voltage difference detection circuit connected to the S phase and the T phase of the three-phase electricity and used to detect a second voltage difference between the S phase and the T phase, and a controller. The controller can determine a phase loss fault based on the level and level flipping of the first voltage difference and the second voltage difference. The detection circuit has a simple structure and low production cost, and can judge the phase loss fault conditions of the R phase, S phase and T phase of the three-phase electricity. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] One or more embodiments are exemplarily described by pictures in the corresponding drawings, and these exemplified descriptions do not constitute limitations on the embodiments. Elements / modules and steps with the same reference numerals in the drawings are represented as similar elements / modules and steps. Unless otherwise specified, the figures in the drawings do not constitute proportional limitations.

[0018] Figure 1 is a structural block diagram of a phase loss detection circuit provided in Embodiment 1 of the present invention;

[0019] Figure 2 yes Figure 1 A schematic diagram of the circuit structure of a first voltage difference detection circuit and a second voltage difference detection circuit in the phase loss detection circuit shown;

[0020] Figure 3 1 is a flow chart of a phase loss detection method provided in Embodiment 2 of the present invention;

[0021] Figure 4 is a schematic diagram of the hardware structure of a controller provided in Embodiment 3 of the present invention;

[0022] Figure 5 is a structural schematic diagram of an air conditioner provided by Embodiment 4 of the present invention;

[0023] : 100, phase loss detection circuit; 110, first voltage difference detection circuit; 120, second voltage difference detection circuit; 130, controller; 131, processor; 132, memory; 10, air conditioner; AC, three-phase electricity; RL, load; L, live wire; N, neutral wire; D1, first conducting diode; D2, second conducting diode; D3, third conducting diode; D4, fourth conducting diode; R1, first current limiting resistor; R2, second current limiting resistor; R3, third current limiting resistor; R4, fourth current limiting resistor; EC1, electrolytic capacitor; U1, first optocoupler; U1A, first light-emitting diode; U1B, first phototransistor; U2, second optocoupler; U2A, second light-emitting diode; U2B, second phototransistor. DETAILED DESCRIPTION

[0024] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0025] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0026] It should be noted that, if there is no conflict, the various features in the embodiments of the present invention can be combined with each other, all within the scope of protection of the present application. In addition, although the functional module division is performed in the device schematic diagram and the logical order is shown in the flow chart, in some cases, it may be different from the module division in the device, or the steps shown or described in the order of execution in the flow chart. In addition, the words "first", "second", "third", "fourth" and the like used herein do not limit the data and the execution order, but only distinguish the same items or similar items with basically the same functions and effects. It should be noted that when an element is described as "connected" to another element, it can be directly connected to another element, or there can be one or more centered elements therebetween.

[0027] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0028] In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0029] In order to solve the problem that in the current three-phase electricity phase loss detection, the phase loss detection of the T phase cannot be realized when there is a load that supplies power to the neutral line in the air-conditioning system, an embodiment of the present invention provides a phase loss detection circuit and method, a controller, and an air conditioner. The detection circuit has a simple structure and low production cost, and the phase loss fault conditions of the R phase, S phase and T phase of the three-phase electricity can be determined by the levels and level flipping conditions of the first voltage difference and the second voltage difference detected by the first voltage difference detection circuit and the second voltage difference detection circuit.

[0030] Specifically, the embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0031] Embodiment 1

[0032] The embodiment of the present invention provides a phase loss detection circuit 100, see Figure 1 , which shows a structural block diagram of a phase loss detection circuit 100 provided in an embodiment of the present invention. The phase loss detection circuit 100 includes: a first voltage difference detection circuit 110, a second voltage difference detection circuit 120 and a controller 130.

[0033] The first voltage difference detection circuit 110, whose input end is connected to the R phase and the S phase of the three-phase AC power, is used to detect the first voltage difference between the R phase and the S phase; the second voltage difference detection circuit 120, whose input end is connected to the S phase and the T phase of the three-phase AC power, is used to detect the second voltage difference between the S phase and the T phase; the controller 130, whose input end is connected to the first voltage difference detection circuit 110 and the second voltage difference detection circuit 120, is configured to determine a phase loss fault based on the level and level flipping of the first voltage difference and the second voltage difference; wherein the R phase or the S phase of the three-phase AC power is connected to the live wire L of the load RL, and the load RL supplies power to the neutral wire N.

[0034] In an embodiment of the present invention, a phase loss detection circuit 100 is provided. The phase loss detection circuit 100 includes a first voltage differential detection circuit 110 connected to the R phase and the S phase of the three-phase AC and used to detect a first voltage differential between the R phase and the S phase, a second voltage differential detection circuit 120 connected to the S phase and the T phase of the three-phase AC and used to detect a second voltage differential between the S phase and the T phase, and a controller 130. The controller 130 can determine a phase loss fault based on the level and level flipping of the first voltage differential and the second voltage differential. The phase loss detection circuit 100 has a simple structure and low production cost, and can judge the phase loss fault conditions of the R phase, the S phase and the T phase of the three-phase AC.

[0035] It should be noted that in Figure 1 In the example shown, the R phase of the three-phase AC is connected to the live wire L of the load RL. Figure 2 In some other embodiments, the live wire L of the load RL may also be connected to the S phase or L phase of the three-phase AC power. The specific configuration may be made according to actual needs and is not limited to the embodiments of the present invention.

[0036] Specifically, see Figure 2 , which shows the circuit structure of a first voltage difference detection circuit 110 and a second voltage difference detection circuit 120 in a phase loss detection circuit 100 provided in an embodiment of the present invention, wherein the first voltage difference detection circuit 110 includes: a first conducting diode D1, whose anode is connected to the R phase of the three-phase AC power; a first optocoupler U1, which includes a first light-emitting diode U1A and a first phototransistor U1B, wherein the anode of the first light-emitting diode U1A is connected to the cathode of the first conducting diode D1, the cathode of the first light-emitting diode U1A is connected to the S phase of the three-phase AC power, and the emitter of the first phototransistor U1B is used to output the first voltage difference.

[0037] Further, in Figure 2In the example shown, the first phototransistor U1B is an NPN transistor, and the collector of the first phototransistor U1B is connected to the power supply. Figure 2 In the example shown, the power supply is a +5V power supply.

[0038] For further information, please see Figure 2 The first voltage difference detection circuit 110 also includes: a first current limiting resistor R1, one end of which is connected to the cathode of the first conducting diode D1; a second current limiting resistor R2, one end of which is connected to the other end of the first current limiting resistor R1, and the other end of which is connected to the anode of the first light-emitting diode U1A; a third conducting diode D3, an anode of which is connected to the cathode of the first light-emitting diode U1A, and a cathode of which is connected to the anode of the first light-emitting diode U1A; an electrolytic capacitor EC1, an anode of which is connected to the collector of the first phototransistor U1B, and a cathode of which is grounded.

[0039] And yes, please continue to see Figure 2 The second voltage difference detection circuit 120 includes: a second conducting diode D2, whose cathode is connected to the T phase of the three-phase AC power; a second optocoupler U2, which includes a second light-emitting diode U2A and a second phototransistor U2B, the cathode of the second light-emitting diode U2A is connected to the anode of the second conducting diode D2, the anode of the second light-emitting diode U2A is connected to the S phase of the three-phase AC power, and the emitter of the second phototransistor U2B is used to output the second voltage difference.

[0040] Further, in Figure 2 In the example shown, the second phototransistor U2B is an NPN transistor, and the collector of the second phototransistor U2B is connected to the power supply. Figure 2 In the example shown, the power supply is a +5V power supply.

[0041] For further information, please see Figure 2 The second voltage difference detection circuit 120 also includes: a third current limiting resistor R3, one end of which is connected to the anode of the second conducting diode D2; a fourth current limiting resistor R4, one end of which is connected to the other end of the third current limiting resistor R3, and the other end of which is connected to the cathode of the second light-emitting diode U2A; a fourth conducting diode D4, an anode of which is connected to the cathode of the second light-emitting diode U2A, and a cathode of which is connected to the anode of the second light-emitting diode U2A.

[0042] The controller 130 may be a microcontroller unit (MCU), a single chip microcomputer / single chip microcomputer or a central processing unit (CPU), etc., which may be selected according to actual needs, and need not be limited to the embodiments of the present invention. In addition, the models of the first conducting diode D1, the second conducting diode D2, the third conducting diode D3, and the fourth conducting diode D4 may be selected according to the requirements for the on-voltage or the off-voltage, the models of the first current limiting resistor R1, the second current limiting resistor R2, the third current limiting resistor R3, and the fourth current limiting resistor R4 may be selected according to the requirements for the resistance value or the current limiting, etc., the model of the electrolytic capacitor EC1 may be selected according to the requirements for overvoltage protection or the filtering, etc., the models of the first optical coupler U1 and the second optical coupler U2 may also be selected according to the requirements for the on-voltage or the off-voltage, etc., and may be specifically designed according to the actual application scenario.

[0043] Embodiment 2

[0044] The present invention provides a method for detecting a phase loss. Figure 3 , which shows a process of a phase loss detection method provided by an embodiment of the present invention, the method includes but is not limited to the following steps:

[0045] Step S110: obtaining a first voltage difference between the R phase and the S phase, and a second voltage difference between the S phase and the T phase through a phase loss detection circuit;

[0046] In the embodiments of the present invention, please refer to Embodiment 1 and Figure 1 and Figure 2 As shown, the voltage difference between the power lines of the two phases is collected by the phase loss detection circuit 100 described in the first embodiment, wherein the first voltage difference AC_R / S between the R phase and the S phase is obtained by the first voltage difference detection circuit 110, and the second voltage difference AC_S / T between the S phase and the T phase is obtained by the second voltage difference detection circuit 120. Then, based on the level and level flipping of the first voltage difference AC_R / S and the second voltage difference AC_S / T, the phase of the power line where the phase loss fault occurs in the three-phase AC can be determined.

[0047] Step S120: when the first voltage difference remains at a high level and no level flip occurs, determining that there is a phase loss fault in the R phase;

[0048] Please also see Figure 2No matter which phase of the power line of the R phase, S phase, or T phase the load RL that supplies power to the neutral line is connected to, when the power line of the R phase is disconnected, the S phase cannot form a voltage difference by connecting to the R phase, and the first conducting diode D1 cannot be turned on, thereby, the first optocoupler U1 cannot be turned on, that is, the first light-emitting diode U1A cannot be turned on, and the first phototransistor U1B cannot be turned on, and the emitter of the first phototransistor U1B maintains a high level, so the first voltage difference AC_R / S maintains a high level, and the first voltage difference AC_R / S does not flip, and at this time it can be determined that there is a phase loss fault in the R phase.

[0049] Step S130: when the first voltage difference and the second voltage difference are reversed in level, it is determined that there is a phase loss fault in the S phase;

[0050] Please also see Figure 2 , no matter which phase of the power line of the R phase, S phase, or T phase the load RL that supplies power to the neutral line is connected to, when the power line of the S phase is disconnected, the first conducting diode D1 and the second conducting diode D2 are both turned on, so that the first optocoupler U1 and the second optocoupler U2 are turned on, that is, the first light-emitting diode U1A and the second light-emitting diode U2A are turned on, the first phototransistor U1B and the second phototransistor U2B are also turned on, the emitter of the first phototransistor U1B and the emitter of the second phototransistor U2B are set to a low level, and the first voltage difference AC_R / S and the second voltage difference AC_S / T are flipped in level, and it can be determined that there is a phase failure in the S phase. It should be noted that in order to avoid false detection, when detecting the S phase, the air-conditioning system needs to be powered off to play a protective role.

[0051] Step S140: when the second voltage difference maintains a high level and no level flip occurs, it is determined that a phase loss fault exists in the T phase.

[0052] Please also see Figure 2 The load RL that supplies power to the neutral line is connected to the power line of the R phase or the S phase, and when the power line of the T phase is disconnected, the second conduction diode D2 cannot be turned on, so that the second optocoupler U2 cannot be turned on, that is, the second light-emitting diode U2A cannot be turned on, and the second phototransistor U2B cannot be turned on, and the emitter of the second phototransistor U2B maintains a high level, so the second voltage difference AC_S / T maintains a high level, and the second voltage difference AC_S / T does not flip, at this time it can be determined that there is a phase loss fault in the T phase.

[0053] It should be noted that the load RL that supplies power to the neutral line is connected to the T phase, and when the power line of the T phase is disconnected, please continue to refer to Figure 2, the power line of the S phase can be connected to the neutral line N through the inductive load connected to the T phase, which will cause the controller 130 to still detect the input voltage of the second voltage difference AC_S / T, and the second conducting diode D2 will still be turned on, thereby causing the second optical coupler U2 to be turned on, so that the second voltage difference AC_S / T outputs a low level, resulting in the inability to detect the phase failure of the T phase. Therefore, in the present application, preferably, the live wire of the load RL is set to be connected to the R phase or S phase of the three-phase AC, so that the phase failure detection of the R phase, S phase, and T phase can be realized; and in some embodiments, if it is only necessary to determine whether the R phase and S phase are phase-deficient, the load RL may not be limited to being connected to the R phase or S phase of the three-phase AC, and can be set according to actual needs.

[0054] Embodiment 3

[0055] The present invention also provides a controller, see Figure 4 , which shows that it is possible to execute Figure 3 The hardware structure of the controller of the phase loss detection method. The controller 130 can be Figure 1 Controller 130 is shown.

[0056] The controller 130 includes: at least one processor 131; and a memory 132 that is communicatively connected to the at least one processor 131. Figure 4 The memory 132 stores instructions that can be executed by the at least one processor 131, and the instructions are executed by the at least one processor 131 so that the at least one processor 131 can perform the above Figure 3 The processor 131 and the memory 132 may be connected via a bus or other means. Figure 4 The example of connecting through bus is taken in the following.

[0057] The memory 132 is a non-volatile computer-readable storage medium that can be used to store non-volatile software programs, non-volatile computer executable programs and modules, such as program instructions / modules corresponding to the phase loss detection method in the embodiment of the present application. The processor 131 executes various functional applications and data processing of the controller by running the non-volatile software programs, instructions and modules stored in the memory 132, that is, implementing the phase loss detection method in the above method embodiment.

[0058] The memory 132 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created according to the use of the phase loss detection device, etc. In addition, the memory 132 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 132 may optionally include a memory remotely arranged relative to the processor 131, and these remote memories may be connected to the phase loss detection device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0059] The one or more modules are stored in the memory 132, and when executed by the one or more processors 131, execute the phase loss detection method in any of the above method embodiments, for example, execute the above described Figure 3 method steps.

[0060] The above-mentioned product can execute the method provided in the embodiment of the present application, and has the functional modules and beneficial effects corresponding to the execution method. For technical details not fully described in this embodiment, please refer to the method provided in the embodiment of the present application.

[0061] The present application also provides a non-volatile computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are executed by one or more processors, for example, to execute the above-described Figure 3 method steps.

[0062] The present application also provides a computer program product, including a computer program stored on a non-volatile computer-readable storage medium, wherein the computer program includes program instructions. When the program instructions are executed by a computer, the computer executes the phase loss detection method in any of the above method embodiments, for example, executing the above described Figure 3 method steps.

[0063] Embodiment 4

[0064] The embodiment of the present invention provides an air conditioner, see Figure 5 , which shows a structural block diagram of an air conditioner provided by an embodiment of the present invention, the air conditioner 10 includes: a load RL and a phase loss detection circuit 100.

[0065] The load RL supplies power to the neutral line, and the live line of the load RL is connected to the R phase or S phase of the three-phase AC power. In the embodiment of the invention, referring to the above-mentioned embodiment 2, it can be seen that by setting the live line of the load RL to be connected to the R phase or S phase of the three-phase AC power, the phase failure detection of any one of the R phase, S phase and T phase power lines can be realized.

[0066] The phase loss detection circuit 100 is the phase loss detection circuit 100 described in Example 1, and the phase loss detection circuit 100 is connected to the R phase, S phase, and T phase of the three-phase AC. For the specific structure of the phase loss detection circuit 100, please refer to Example 1 and Figure 1 to Figure 2 For the specific working principle of the phase loss detection circuit 100 and the detection method performed by the controller 130 in the phase loss detection circuit 100, please refer to the second embodiment and Figure 3 The above is not described in detail here.

[0067] In an embodiment of the present invention, a phase loss detection circuit and method, a controller, and an air conditioner are provided. The phase loss detection circuit includes a first voltage differential detection circuit connected to the R phase and the S phase of three-phase electricity and used to detect a first voltage differential between the R phase and the S phase, a second voltage differential detection circuit connected to the S phase and the T phase of the three-phase electricity and used to detect a second voltage differential between the S phase and the T phase, and a controller. The controller can determine a phase loss fault based on the level and level flipping of the first voltage differential and the second voltage differential. The detection circuit has a simple structure and low production cost, and can judge the phase loss fault conditions of the R phase, the S phase, and the T phase of the three-phase electricity.

[0068] It should be noted that the device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, and may be located in one place or distributed over multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0069] Through the description of the above implementation methods, ordinary technicians in this field can clearly understand that each implementation method can be implemented by means of software plus a general hardware platform, and of course, it can also be implemented by hardware. Ordinary technicians in this field can understand that all or part of the processes in the above-mentioned embodiment method can be completed by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, the storage medium can be a disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may also be combined, the steps may be implemented in any order, and there are many other changes in different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A phase loss detection circuit, characterized in that: include: A first voltage difference detection circuit, whose input end is connected to the R phase and the S phase of the three-phase electricity, and is used to detect a first voltage difference between the R phase and the S phase; A second voltage difference detection circuit, whose input end is connected to the S phase and the T phase of the three-phase electricity, is used to detect a second voltage difference between the S phase and the T phase; a controller, whose input end is connected to the first voltage differential detection circuit and the second voltage differential detection circuit, and configured to determine a phase loss fault based on the level and level flipping of the first voltage differential and the second voltage differential; The R phase or S phase of the three-phase electricity is connected to the live wire of the load, and the load supplies power to the neutral wire.

2. The phase loss detection circuit according to claim 1, characterized in that: The first voltage difference detection circuit comprises: A first conducting diode, an anode of which is connected to the R phase of the three-phase electricity; The first optocoupler includes a first light-emitting diode and a first phototransistor, wherein the anode of the first light-emitting diode is connected to the cathode of the first conducting diode, the cathode of the first light-emitting diode is connected to the S phase of the three-phase electricity, and the emitter of the first phototransistor is used to output the first voltage difference.

3. The phase loss detection circuit according to claim 2, characterized in that: The first phototransistor is an NPN-type transistor, and the collector of the first phototransistor is connected to a power supply.

4. The phase loss detection circuit according to claim 2, characterized in that: The first voltage difference detection circuit also includes: A first current limiting resistor, one end of which is connected to the cathode of the first conducting diode; a second current limiting resistor, one end of which is connected to the other end of the first current limiting resistor, and the other end of which is connected to the anode of the first light emitting diode; a third conducting diode, whose anode is connected to the cathode of the first light-emitting diode, and whose cathode is connected to the anode of the first light-emitting diode; The electrolytic capacitor has an anode connected to the collector of the first phototransistor and a cathode connected to the ground.

5. The phase loss detection circuit according to claim 1, characterized in that: The second voltage difference detection circuit comprises: A second conducting diode, a cathode of which is connected to the T phase of the three-phase electricity; The second optocoupler includes a second light-emitting diode and a second phototransistor, wherein the cathode of the second light-emitting diode is connected to the anode of the second conducting diode, the anode of the second light-emitting diode is connected to the S phase of the three-phase electricity, and the emitter of the second phototransistor is used to output the second voltage difference.

6. The phase loss detection circuit according to claim 5, characterized in that: The second phototransistor is an NPN-type transistor, and the collector of the second phototransistor is connected to a power supply.

7. The phase loss detection circuit according to claim 5, characterized in that: The second voltage difference detection circuit also includes: a third current limiting resistor, one end of which is connected to the anode of the second conducting diode; a fourth current limiting resistor, one end of which is connected to the other end of the third current limiting resistor, and the other end of which is connected to the cathode of the second light emitting diode; A fourth conducting diode has an anode connected to the cathode of the second light emitting diode, and a cathode connected to the anode of the second light emitting diode.

8. A phase loss detection method, characterized in that: The method comprises: Obtaining a first voltage difference between the R phase and the S phase, and a second voltage difference between the S phase and the T phase by the phase loss detection circuit according to any one of claims 1 to 7; When the first voltage difference maintains a high level and no level flip occurs, determining that there is a phase loss fault in the R phase; When the first voltage difference and the second voltage difference have a level flip, it is determined that there is a phase loss fault in the S phase; When the second voltage difference maintains a high level and no level flip occurs, it is determined that a phase loss fault exists in the T phase.

9. A controller, characterized in that: include: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, wherein the instructions are executed by the at least one processor to enable the at least one processor to perform the method of claim 8 .

10. An air conditioner, characterized in that: include: A load, which supplies power to the neutral line, and a live line of the load is connected to the R phase or the S phase of the three-phase electricity; The phase loss detection circuit according to any one of claims 1 to 7, wherein the phase loss detection circuit is connected to the R phase, S phase, and T phase of the three-phase electricity.

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