Phase loss detection circuit and electronic equipment

Abstract

The present application provides a phase loss detection circuit and electronic device, relating to the field of phase loss detection technology. The phase loss detection circuit includes a first phase line, a second phase line, a third phase line, a neutral line, associated components, and a phase loss detector. The first phase line, the second phase line, and the third phase line are all electrically connected to the neutral line through the associated components, so that the voltages of the first phase line, the second phase line, and the third phase line are all associated with the voltage of the neutral line; the phase loss detector includes a detection circuit and a main chip, the first end of the detection circuit is electrically connected to the first phase line, the second phase line, and the third phase line respectively, the second end of the detection circuit is electrically connected to the neutral line, and the third end of the detection circuit is electrically connected to the main chip to transmit the signal generated by comparing the combined voltage of the first phase line, the second phase line, and the third phase line with the neutral line voltage to the main chip. The present application has the advantage of being able to simultaneously detect whether the three phase lines and the neutral line are phase-loss.

Description

Technical Field

[0001] The present application relates to the technical field of phase loss detection, and in particular to a phase loss detection circuit and electronic equipment. Background Art

[0002] AC three-phase, four-wire distribution lines consist of three phase conductors and one neutral conductor. If a phase loss occurs due to a break or loosening of the neutral conductor, the neutral conductor potential on the load side is determined by the load balance connected via the neutral conductor on the negative voltage side of the phase loss point. Therefore, if the load is unbalanced, an abnormal voltage may be applied to the load, causing damage to the loaded equipment.

[0003] At the same time, when a phase loss occurs due to wire breakage or connection line detachment in other phases of the three-phase system, the current in the three-phase circuit connected to the three-phase AC power supply becomes unbalanced, and overcurrent will occur in other phases, causing the machine to burn out.

[0004] Therefore, phase loss detection is crucial. However, in the prior art, when performing phase loss detection, only the neutral line can be detected to see if it is missing, or the neutral line cannot be detected to see if it is missing, and it is impossible to simultaneously detect if the three phase lines and the neutral line are missing. Summary of the Invention

[0005] The purpose of this application is to provide a phase loss detection circuit and electronic equipment to solve the problem in the prior art that it is impossible to simultaneously detect whether three phase lines and a neutral line are phase-loss.

[0006] To address the above-mentioned problems, on the one hand, the present application provides a phase loss detection circuit, which includes a first phase line, a second phase line, a third phase line, a neutral line, associated components, and a phase loss detector, wherein the first phase line, the second phase line, the third phase line, and the neutral line are all used to be electrically connected to a power source, and the first phase line, the second phase line, and the third phase line are all electrically connected to the neutral line through the associated components, so that the voltages of the first phase line, the second phase line, and the third phase line are all associated with the voltage of the neutral line;

[0007] The phase loss detector includes a detection circuit and a main chip, wherein a first end of the detection circuit is electrically connected to the first phase line, the second phase line, and the third phase line, respectively, a second end of the detection circuit is electrically connected to the neutral line, and a third end of the detection circuit is electrically connected to the main chip to transmit a signal generated by comparing the combined voltage of the first phase line, the second phase line, and the third phase line with the neutral line voltage to the main chip; wherein:

[0008] When the main chip receives the first signal, it determines that the first phase line, the second phase line, the third phase line and the neutral line are working normally;

[0009] When the main chip receives the second signal, it determines that at least one phase of the first phase line, the second phase line, the third phase line, and the neutral line is missing.

[0010] Since the present application uses associated devices to connect the three phase lines and the neutral line, when any one of the three phase lines and the neutral line is out of phase, it will affect the voltage of other lines. At the same time, since the phase loss detector uses the combined voltage of the three phase lines to compare with the voltage of the neutral line, when any one of the three phase lines and the neutral line is out of phase, the voltage difference between the combined voltage of the three phase lines and the neutral line changes, thereby enabling the main chip to receive different signals and realize phase loss detection of the circuit.

[0011] Optionally, the detection circuit includes a sampling module and a comparison module, the first phase line, the second phase line, and the third phase line are electrically connected to a first end of the comparison module through the sampling module, a second end of the comparison module is electrically connected to the neutral line, and a third end of the comparison module is electrically connected to the main chip;

[0012] When the voltage at the first terminal of the comparison module is greater than the voltage at the second terminal, the comparison module outputs a low / high level signal to the main chip;

[0013] When the voltage of the first terminal of the comparison module is less than the voltage of the second terminal, the comparison module outputs a high / low level signal to the master chip.

[0014] Optionally, the sampling module includes a first resistor and a diode, the resistor is connected in series with an anode of the diode, and a cathode of the diode is electrically connected to the first end of the comparison module.

[0015] Optionally, the comparison module includes an optocoupler, a second resistor, and a driving power supply, the optocoupler includes a light-emitting diode and a light-receiving transistor, the anode of the light-emitting diode is electrically connected to the sampling module, and the cathode of the light-receiving transistor is electrically connected to the neutral line; the emitter of the light-receiving transistor is grounded, the collector of the light-receiving transistor is electrically connected to one end of the second resistor and the main chip, respectively, and the other end of the second resistor is electrically connected to the driving power supply;

[0016] When the voltage at the first terminal of the comparison module is greater than the voltage at the second terminal, the comparison module outputs a low level signal to the main chip;

[0017] When the voltage at the first end of the comparison module is less than the voltage at the second end, the comparison module outputs a high level signal to the master chip.

[0018] Optionally, the output ends of the first phase line, the second phase line, and the third phase line are electrically connected to a load, and the phase loss detection circuit also includes a control power supply, one end of the control power supply is electrically connected to the neutral line, and the other end of the control power supply is electrically connected to the first phase line, the second phase line or the third phase line, respectively, and the control power supply is used to drive the load to work.

[0019] Optionally, the associated components include capacitors and resistors, and the first phase line, the second phase line, and the third phase line are electrically connected to the neutral line via the capacitors and / or the resistors, respectively.

[0020] Optionally, the phase loss detection circuit further includes a filter, the filter includes the associated device and a coil, and the coil is arranged on the first phase line, the second phase line and the third phase line.

[0021] Optionally, the phase loss detection circuit further includes a phase line switch, which is installed on the first phase line, the second phase line, and the third phase line, and is electrically connected to the main chip;

[0022] When the main chip receives the second signal, the main chip controls the phase line switch to be disconnected.

[0023] Optionally, the phase loss detection circuit also includes a rectifier and an inverter, the output ends of the first phase line, the second phase line and the third phase line are electrically connected to the rectifier, the output end of the rectifier is electrically connected to the inverter, and the output end of the inverter is used to be electrically connected to the load.

[0024] On the other hand, the present application further provides an electronic device, which includes a load and the above-mentioned phase loss detection circuit, and the output end of the phase loss detection circuit is electrically connected to the load. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of a phase loss detection circuit according to an embodiment of the present invention.

[0026] Figure 2 A module schematic diagram of another phase loss detection circuit provided in an embodiment of the present application.

[0027] Figure 3 This is a circuit diagram of the filter provided in an embodiment of the present application.

[0028] Figure 4 This is a first simulation diagram provided for an embodiment of the present application.

[0029] Figure 5 This is a second simulation diagram provided in an embodiment of the present application.

[0030] Figure 6 This is a third simulation diagram provided in an embodiment of the present application.

[0031] Figure 7 This is a fourth simulation diagram provided in an embodiment of the present application.

[0032] Description of reference numerals:

[0033] 100-phase loss detection circuit; 110-first phase line; 120-second phase line; 130-third phase line; 140-neutral line; 150-associated components; 160-phase loss detector; 170-filter; 180-phase line switch; 190-rectifier; 200-inverter. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0035] Three-phase four-wire refers to a wiring arrangement consisting of three live wires and one neutral wire. There are two types of connections: star and delta, with star being the most common. A three-phase symmetrical power supply is an AC power source that provides three equal electromotive forces (or voltages) at the same frequency and 120° out of phase with each other. A circuit powered by a three-phase power supply is called a three-phase circuit.

[0036] As described in the background technology, for AC 3-phase 4-wire distribution lines, the existing technology can only detect whether the neutral line is missing, or cannot detect whether the neutral line is missing, and cannot simultaneously detect whether the three phase lines and the neutral line are missing.

[0037] In view of this, the present application provides a phase loss detection circuit, which sets a phase loss detector and connects the phase loss detector to three phase lines and a neutral line. The combined voltage of the three phase lines is compared with the neutral line voltage to determine whether there is a phase loss in the three phase lines and the neutral line.

[0038] The following is an exemplary description of the phase loss detection circuit provided in this application:

[0039] As an optional implementation, see Figure 1The phase loss detection circuit 100 includes a first phase line 110, a second phase line 120, a third phase line 130, a neutral line 140, an associated device 150, and a phase loss detector 160. The first phase line 110, the second phase line 120, the third phase line 130, and the neutral line 140 are all used to be electrically connected to a power supply. The first phase line 110, the second phase line 120, and the third phase line 130 are all electrically connected to the neutral line 140 through the associated device 150, so that the voltages of the first phase line 110, the second phase line 120, and the third phase line 130 are all associated with the voltage of the neutral line 140. The phase loss detector 160 includes a detection circuit and a main chip. The first end of the detection circuit is electrically connected to the first phase line 110, the second phase line 120 and the third phase line 130 respectively, the second end of the detection circuit is electrically connected to the neutral line 140, and the third end of the detection circuit is electrically connected to the main chip to transmit the signal generated by comparing the combined voltage of the first phase line 110, the second phase line 120 and the third phase line 130 with the voltage of the neutral line 140 to the main chip; when the main chip receives the first signal, it determines that the first phase line 110, the second phase line 120, the third phase line 130 and the neutral line 140 are working normally; when the main chip receives the second signal, it determines that at least one of the first phase line 110, the second phase line 120, the third phase line 130 and the neutral line 140 is missing a phase.

[0040] The phase loss detection circuit provided in the present application can simultaneously detect whether the three phase lines and the neutral line 140 are phase-loss. At the same time, detection can be achieved even in the absence of load, and the efficiency of phase loss detection is higher.

[0041] The first phase line 110 , the second phase line 120 , and the third phase line 130 may represent phases U, V, and W, respectively. Since the three phase lines are connected to the neutral line 140 via the associated device 150 , when the neutral line 140 is missing a phase, the voltage of the neutral line 140 is affected by the first phase line 110 , the second phase line 120 , and the third phase line 130 .

[0042] When the circuit is operating normally, the total voltage of the first phase line 110, the second phase line 120, and the third phase line 130 is generally greater than the voltage of the neutral line 140. When the neutral line 140 is missing a phase, due to the influence of the associated device 150 between the first phase line 110, the second phase line 120, the third phase line 130 and the neutral line 140, the voltage of the neutral line 140 will increase, and will exceed the combined voltage of the first phase line 110, the second phase line 120, and the third phase line 130 during part of each voltage cycle; and when any one of the first phase line 110, the second phase line 120, and the third phase line 130 is missing a phase, the phase line voltage of the missing phase no longer changes. At this time, the voltage of the neutral line 140 will also appear in a range that is larger than the combined voltage of the first phase line 110, the second phase line 120, and the third phase line 130. By using a detection circuit to compare the combined voltage of the first phase line 110, the second phase line 120 and the third phase line 130 with the voltage of the neutral line 140, the main chip can receive different signals when a phase is missing, thereby determining whether there is a phase missing condition in the circuit.

[0043] As an implementation, the detection circuit includes a sampling module and a comparison module. The first phase line 110, the second phase line 120, and the third phase line 130 are each electrically connected to the first end of the comparison module through the sampling module, the second end of the comparison module is electrically connected to the neutral line 140, and the third end of the comparison module is electrically connected to the main chip. That is, in this application, three sampling modules are included, wherein the first phase line 110 is electrically connected to the comparison module through a sampling module, the second phase line 120 is electrically connected to the comparison module through a sampling module, and the third phase line 130 is electrically connected to the comparison module through a sampling module, so that the voltage at the first end of the comparison module is the combined voltage of the first phase line 110, the second phase line 120, and the third phase line 130, and the voltage at the second end of the comparison module is the voltage of the neutral line 140.

[0044] On this basis, when the voltage of the first end of the comparison module is greater than the voltage of the second end, the comparison module outputs a low / high level signal to the main chip; when the voltage of the first end of the comparison module is less than the voltage of the second end, the comparison module outputs a high / low level signal to the main chip.

[0045] In other words, the comparison module compares the voltage at the first end with the voltage at the second end, and outputs a corresponding signal accordingly, wherein the signal output when the voltage at the first end of the comparison module is greater than the voltage at the second end is opposite to the signal output when the voltage at the first end of the comparison module is less than the voltage at the second end. For example, when the voltage at the first end of the comparison module is greater than the voltage at the second end, the comparison module outputs a low-level signal to the main chip. On this basis, when the voltage at the first end of the comparison module is less than the voltage at the second end, the comparison module outputs a high-level signal to the main chip. Alternatively, when the voltage at the first end of the comparison module is greater than the voltage at the second end, the comparison module outputs a high-level signal to the main chip. On this basis, when the voltage at the first end of the comparison module is less than the voltage at the second end, the comparison module outputs a low-level signal to the main chip. This is not limited here.

[0046] Optionally, see Figure 2 The sampling module includes a first resistor and a diode, the first resistor is connected in series with the anode of the diode, and the cathode of the diode is electrically connected to the first end of the comparison module. Figure 2 As shown in FIG, R1, R2, and R3 are first resistors, and D1, D2, and D3 are diodes. In other words, the first phase line 110 is electrically connected to the neutral line 140 via a first resistor and a diode, the second phase line 120 is electrically connected to the neutral line 140 via a first resistor and a diode, and the third phase line 130 is electrically connected to the neutral line 140 via a first resistor and a diode. The voltages are then combined at the first end of the sampling module.

[0047] As an implementation method, the comparison module includes an optocoupler PC, a second resistor R4, and a driving power supply Vcc. The optocoupler PC includes a light-emitting diode and a light-receiving transistor. The anode of the light-emitting diode is electrically connected to the sampling module, and the cathode of the light-emitting diode is electrically connected to the neutral line 140. The emitter of the light-receiving transistor is grounded, and the collector of the light-receiving transistor is electrically connected to one end of the second resistor and the main chip, respectively. The other end of the second resistor is electrically connected to the driving power supply. On this basis, when the voltage at the first end of the comparison module is greater than the voltage at the second end, the light-emitting diode turns on and emits light, causing the light-receiving transistor to turn on. At this time, the voltage of the main chip is pulled to ground, and the comparison module outputs a low-level signal to the main chip. When the voltage at the first end of the comparison module is less than the voltage at the second end, the light-emitting diode is in the off state. Correspondingly, the light-receiving transistor will not turn on. At this time, the comparison module outputs a high-level signal to the main chip.

[0048] Since when any one of the first phase line 110, the second phase line 120, the third phase line 130 and the neutral line 140 is missing, the total voltage of the three phase lines will be lower than the voltage of the neutral line 140 in a certain range, when the main chip receives a high-level signal, it can determine that at least one of the first phase line 110, the second phase line 120, the third phase line 130 and the neutral line 140 is missing.

[0049] On this basis, taking this embodiment as an example, the first signal is a continuous low-level signal, and the second signal is a periodic pulse signal.

[0050] As another possible implementation of the present application, the comparison module can also be a comparator, wherein the comparator's non-inverting input is electrically connected to each of the three sampling modules, the comparator's inverting input is electrically connected to the neutral line, and the comparator's output is electrically connected to the main chip. The comparator then compares the combined voltage of the first phase line 110, the second phase line 120, and the third phase line 130 with the voltage of the neutral line 140 to determine the signal output to the main chip.

[0051] As a possible implementation, the associated device 150 includes a capacitor and a resistor, and the first phase line 110 , the second phase line 120 , and the third phase line 130 are electrically connected to the neutral line 140 via the capacitor and / or the resistor, respectively.

[0052] Optionally, the phase loss detection circuit further includes a filter 170, the structure of the filter 170 is as follows: Figure 3 As shown, the filter 170 includes an associated device 150 and a coil, and the coil is arranged on the first phase line 110, the second phase line 120 and the third phase line 130. In other words, Figure 2 As shown, the associated device 150 described in this application can be a part of the filter 170; or, as shown in FIG. Figure 1 As shown, the associated components described in this application may also exist independently, and this is not limited. It should be noted that when the associated components are part of a filter, the capacitors and inductors in the filter can achieve the filtering function.

[0053] As an implementation method, a three-phase, four-wire AC power source inputs three AC lines (U, V, W), a neutral line (140N), and a ground line (E) to filter 170. Filter 170, comprised of several capacitors, coils, and resistors, absorbs noise output from the circuit and reduces its level. As shown in the figure, capacitors and resistors are installed between the three phase lines, the neutral line (140), and the ground line. To reduce noise, coils are also installed on each line. This arrangement reduces common-mode noise in the same phase and normal-mode noise in the opposite phase between the phase lines. Because capacitors, resistors, and other components are connected between each phase of filter 170, the effects of voltage between the phases are propagated. Therefore, if a phase loss occurs in the first phase line (110), the second phase line (120), the third phase line (130), or the neutral line (140), the phase with the loss will also affect the other phases.

[0054] Optionally, the phase loss detection circuit 100 further includes a rectifier 190 and an inverter 200. The output ends of the first phase line 110, the second phase line 120, and the third phase line 130 are electrically connected to the rectifier 190. The output end of the rectifier 190 is electrically connected to the inverter 200, and the output end of the inverter 200 is electrically connected to the load. Specifically, the rectifier 190 and the inverter 200 for driving the motor are mounted at the rear end of the phase loss detector 160. The AC power passing through the filter 170 is converted to DC by the rectifier 190, and then converted to AC power of the desired frequency by the inverter 200, thereby driving the motor.

[0055] Phase loss detection circuit 100 also includes a control power supply, one end of which is electrically connected to neutral line 140, and the other end of which is electrically connected to first phase line 110, second phase line 120, or third phase line 130. The control power supply is used to drive the load. Because the driving power is derived from a single-phase power source between any phase line and neutral line 140 in the three-phase AC system, three-phase AC loads are prone to voltage imbalance between the three phases. This means that when a phase loss occurs, an abnormal voltage imbalance occurs between the three phases, enabling the determination of a phase loss.

[0056] Phase loss detection circuit 100 also includes phase switches 180, which are installed on first, second, and third phase lines 110, 120, and 130 and are electrically connected to the main chip. When the main chip receives the second signal, it controls phase switches 180 to open. By providing phase switches 180, when phase loss detector 160 detects a phase loss anomaly, power to rectifier 190 is cut off, protecting the entire circuit and load.

[0057] The following uses the comparison module including an optocoupler, a second resistor, and a drive power supply, and the load as an example to analyze the different states of the circuit:

[0058] The combined voltage output by the three diodes on the first, second, and third phase lines 110, 120, and 130 represents the maximum voltage of each phase of the three-phase AC. Under normal conditions, the maximum voltage of each phase is higher than the voltage of the neutral line 140. Therefore, when there is no phase loss, the optocoupler is in the ON state. When the main chip detects that the optocoupler output is ON, it indicates that there is no phase loss.

[0059] Figure 4 This example shows the simulation results of detection operation under normal conditions. It shows the resistance of each line of the three-phase AC when the motor is driven, the combined output voltage of the three diodes connected in series, that is, the maximum voltage of the three phases, the neutral line 140 voltage on the motor drive side, the output detection pulse of the optocoupler, and the simulation results showing the time-lapse of the output DC voltage of the converter.

[0060] It should be noted that these simulation results are based on a power supply frequency of 50Hz. Under normal circumstances, the maximum three-phase voltage and the voltage of neutral line 140 fluctuate at three times the power supply frequency. Typically, the maximum three-phase voltage is greater than the voltage of neutral line 140. Therefore, the optocoupler of phase loss detector 160 is normally in the ON state, and the optocoupler output is always low. If the main chip detects that the optocoupler output is normally and continuously low, it determines that there is no phase loss and outputs the result.

[0061] Figure 5 The following example shows the simulation results of the detection action when the neutral line 140 is missing. Figure 3 When a phase loss occurs on neutral line 140, the maximum three-phase voltage and the voltage on neutral line 140 fluctuate significantly due to the phase loss. This means that the voltage on neutral line 140 increases due to the influence of the coils, capacitors, and control power supply between the three-phase and neutral lines 140, resulting in intervals where the maximum three-phase voltage is lower than the voltage on neutral line 140. Because the optocoupler of phase loss detector 160 turns off during the power frequency cycle, the optocoupler output periodically turns on. The main chip detects phase loss by detecting power frequency pulses in the optocoupler output and outputs the result.

[0062] Figure 6 The following example shows the simulation results of the detection action when the U phase is missing. Figure 3When any one of the three phases is lost, the three-phase maximum voltage and the neutral line 140 voltage cease to fluctuate due to the phase loss, causing one phase to cease fluctuating. The power supply frequency fluctuates significantly at a period twice the power supply frequency. Because the neutral line 140 voltage is the average of the three-phase voltages, a range occurs where the neutral line 140 voltage is greater than the three-phase maximum voltage. Because the optocoupler of phase loss detector 160 turns off during the power supply frequency cycle, the optocoupler output periodically turns on. The main chip detects phase loss by detecting power supply frequency pulses in the optocoupler output and outputs the result.

[0063] Figure 7 The simulation results of the detection action when the T phase is missing are shown, and Figure 6 The same principle can detect phase loss. In addition, because the output DC voltage of the converter changes greatly at 2 times the power supply frequency, Figure 4 Compared with the normal DC voltage displayed, the inverter's driving force on the motor is insufficient and cannot achieve normal drive. Therefore, the phase loss detection circuit 100 of this application is provided with a phase line switch 180. The main chip can control the phase line switch 180 to disconnect to stop abnormal operation and achieve safe operation.

[0064] In addition, the existing phase loss detection can only be performed in the operating state, while the phase loss detection circuit 100 of the present application detects and determines the phase loss through the difference between the maximum voltage of the three phases (i.e., the combined voltage of the three phases) and the voltage of the neutral line 140, so the phase loss can be detected even when the device has no load.

[0065] It is understood that the phase loss detection circuit 100 provided in this application can not only simultaneously detect whether the three phase lines and the neutral line 140 are missing, but also realize phase loss detection when there is no load and the circuit is equipped with a filter 170. During the detection, the presence of a phase loss is detected by checking whether there is a periodic signal on the output side of the optocoupler connected between the output of the voltage synthesis circuit and the neutral line 140 of the AC power supply.

[0066] On this basis, the present application further provides an electronic device, which includes a load and the above-mentioned phase loss detection circuit 100, wherein the output end of the phase loss detection circuit 100 is electrically connected to the load. Optionally, the electronic device described in the present application can be an air conditioner or other device.

[0067] In summary, the present application provides a phase loss detection circuit 100 and an electronic device, the phase loss detection circuit 100 includes a first phase line 110, a second phase line 120, a third phase line 130, a neutral line 140, an associated device 150 and a phase loss detector 160, the first phase line 110, the second phase line 120, the third phase line 130 and the neutral line 140 are all used to be electrically connected to a power supply, the first phase line 110, the second phase line 120 and the third phase line 130 are all electrically connected to the neutral line 140 through the associated device 150, so that the voltages of the first phase line 110, the second phase line 120 and the third phase line 130 are all associated with the voltage of the neutral line 140; the phase loss detector 160 includes a detection circuit and a main The chip comprises a first end of the detection circuit electrically connected to the first phase line 110, the second phase line 120 and the third phase line 130, respectively, a second end of the detection circuit electrically connected to the neutral line 140, and a third end of the detection circuit electrically connected to the main chip, so as to transmit a signal generated by comparing the combined voltage of the first phase line 110, the second phase line 120 and the third phase line 130 with the voltage of the neutral line 140 to the main chip; wherein, when the main chip receives the first signal, it determines that the first phase line 110, the second phase line 120, the third phase line 130 and the neutral line 140 are working normally; when the main chip receives the second signal, it determines that at least one of the first phase line 110, the second phase line 120, the third phase line 130 and the neutral line 140 is missing a phase. Since the present application utilizes an associated device 150 to connect the three phase lines to the neutral line 140, when any one of the three phase lines and the neutral line 140 is out of phase, it will affect the voltage of other lines. At the same time, since the phase loss detector 160 compares the combined voltage of the three phase lines with the voltage of the neutral line 140, when any one of the three phase lines and the neutral line 140 is out of phase, the voltage difference between the combined voltage of the three phase lines and the neutral line 140 changes, thereby enabling the main chip to receive different signals and realize phase loss detection of the circuit.

[0068] Although the present application is disclosed as above, the present application is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be based on the scope defined by the claims.

Claims

1. A phase loss detection circuit (100), characterized in that: The phase loss detection circuit (100) comprises a first phase line (110), a second phase line (120), a third phase line (130), a neutral line (140), associated devices (150) and a phase loss detector (160), wherein the first phase line (110), the second phase line (120), the third phase line (130) and the neutral line (140) are all used to be electrically connected to a power source, and the first phase line (110), the second phase line (120) and the third phase line (130) are all electrically connected to a power source. The first phase line (110), the second phase line (120), and the third phase line (130) are electrically connected to the neutral line (140) through the associated device (150), so that the voltages of the first phase line (110), the second phase line (120), and the third phase line (130) are associated with the voltage of the neutral line (140); wherein the associated device (150) includes a capacitor and a resistor, and the first phase line (110), the second phase line (120), and the third phase line (130) are electrically connected to the neutral line (140) through the capacitor and / or the resistor respectively; When the phase loss detection circuit operates normally, the combined voltage of the first phase line (110), the second phase line (120), and the third phase line (130) is greater than the voltage of the neutral line (140); when any one of the first phase line (110), the second phase line (120), the third phase line (130), and the neutral line (140) is phase-lost, the voltage of the neutral line (140) exceeds the combined voltage of the first phase line (110), the second phase line (120), and the third phase line (130) during a portion of each voltage cycle; The phase loss detector (160) includes a detection circuit and a main chip, wherein a first end of the detection circuit is electrically connected to the first phase line (110), the second phase line (120) and the third phase line (130), respectively, a second end of the detection circuit is electrically connected to the neutral line (140), and a third end of the detection circuit is electrically connected to the main chip to transmit a signal generated by comparing the combined voltage of the first phase line (110), the second phase line (120) and the third phase line (130) with the voltage of the neutral line (140) to the main chip; wherein, When the main chip receives the first signal generated after the comparison, it determines that the first phase line (110), the second phase line (120), the third phase line (130), and the neutral line (140) are operating normally; When the main chip receives the second signal generated after the comparison, it determines that at least one of the first phase line (110), the second phase line (120), the third phase line (130) and the neutral line (140) is missing.

2. The phase loss detection circuit (100) according to claim 1, characterized in that: The detection circuit comprises a sampling module and a comparison module, wherein the first phase line (110), the second phase line (120) and the third phase line (130) are electrically connected to a first end of the comparison module through the sampling module, a second end of the comparison module is electrically connected to the neutral line (140), and a third end of the comparison module is electrically connected to the main chip; When the voltage at the first terminal of the comparison module is greater than the voltage at the second terminal of the comparison module, the comparison module outputs a low / high level signal to the main chip; When the voltage at the first terminal of the comparison module is less than the voltage at the second terminal of the comparison module, the comparison module outputs a high / low level signal to the master chip.

3. The phase loss detection circuit (100) according to claim 2, characterized in that: The sampling module includes a first resistor and a diode, wherein the first resistor is connected in series with an anode of the diode, and a cathode of the diode is electrically connected to a first end of the comparison module.

4. The phase loss detection circuit (100) according to claim 2, characterized in that: The comparison module includes an optocoupler, a second resistor, and a driving power supply. The optocoupler includes a light-emitting diode and a light-receiving transistor. The anode of the light-emitting diode is electrically connected to the sampling module, and the cathode of the light-emitting diode is electrically connected to the neutral line (140). The emitter of the light-receiving transistor is grounded, and the collector of the light-receiving transistor is electrically connected to one end of the second resistor and the main chip respectively. The other end of the second resistor is electrically connected to the driving power supply. When the voltage at the first terminal of the comparison module is greater than the voltage at the second terminal of the comparison module, the comparison module outputs a low level signal to the main chip; When the voltage at the first terminal of the comparison module is less than the voltage at the second terminal of the comparison module, the comparison module outputs a high level signal to the master chip.

5. The phase loss detection circuit (100) according to claim 1, characterized in that: The output ends of the first phase line (110), the second phase line (120), and the third phase line (130) are electrically connected to a load. The phase loss detection circuit (100) further includes a control power supply, one end of which is electrically connected to the neutral line (140), and the other end of which is electrically connected to the first phase line (110), the second phase line (120), or the third phase line (130), respectively. The control power supply is used to drive the load to operate.

6. The phase loss detection circuit (100) according to claim 1, characterized in that: The phase loss detection circuit further comprises a filter (170), wherein the filter (170) comprises the associated device (150) and a coil, wherein the coil is arranged on the first phase line (110), the second phase line (120), and the third phase line (130).

7. The phase loss detection circuit (100) according to claim 1, characterized in that: The phase loss detection circuit (100) further includes a phase line switch (180), the phase line switch (180) being installed on the first phase line (110), the second phase line (120), and the third phase line (130), and the phase line switch (180) being electrically connected to the main chip; When the main chip receives the second signal, the main chip controls the phase line switch (180) to be disconnected.

8. The phase loss detection circuit (100) according to claim 1, characterized in that: The phase loss detection circuit (100) further comprises a rectifier (190) and an inverter (200); the output ends of the first phase line (110), the second phase line (120), and the third phase line (130) are electrically connected to the rectifier (190); the output end of the rectifier (190) is electrically connected to the inverter (200); and the output end of the inverter (200) is used to be electrically connected to a load.

9. An electronic device, characterized in that: The electronic device comprises a first load and the phase loss detection circuit (100) according to any one of claims 1 to 8, and an output end of the phase loss detection circuit (100) is electrically connected to the first load.

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