Power supply detection circuit and air conditioner

Abstract

The utility model discloses a power supply detection circuit and an air conditioner, and the power supply detection circuit comprises a voltage processing circuit, a first collection end is used for connecting a neutral line of an external power supply, a second collection end is used for connecting a one-phase live line of the external power supply, and the voltage processing circuit is used for collecting the voltage of the neutral line and carrying out the voltage reduction processing. Collecting the voltage of the live wire, and performing voltage reduction processing; the bias voltage generating circuit is used for processing the direct-current power supply into corresponding bias voltage and outputting the bias voltage; the first input end of the differential circuit is connected with the first output end, the second input end of the differential circuit is connected with the second output end, and the differential circuit is used for carrying out differential processing on the voltage-reduced neutral line voltage and the voltage-reduced live line voltage according to the bias voltage and outputting a phase voltage detection signal of a corresponding waveform. Through the phase voltage detection signal with the waveform, the determination of various voltage abnormal conditions can be realized, the occupied space of a detection device can be reduced, and the cost is further reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to air conditioner technical field especially relates to a power supply detection circuit and air conditioner. BACKGROUND

[0002] In the air conditioner, there are models using multiphase power supply such as three-phase power supply, compared with single-phase alternating current, three-phase alternating current has the advantages of high efficiency, saving materials, clear waveform and the like.

[0003] Among them, three-phase power supply generally requires voltage anomaly detection functions such as phase error, phase loss and overvoltage and undervoltage, to ensure the stability and reliability of power supply. In the related art, the detection method used is voltage reduction and optocoupler conversion signal, which realizes phase error and phase loss detection, but for overvoltage and undervoltage detection, corresponding detection modules need to be added, which increases the installation space and cost. UTILITY MODEL CONTENTS

[0004] The main purpose of the utility model is to provide a power supply detection circuit and air conditioner, aiming at reducing the space and cost occupied by the detection device.

[0005] To achieve the above purpose, the power supply detection circuit provided by the utility model comprises:

[0006] A voltage processing circuit comprising a first collection end, a second collection end, a first output end and a second output end, the first collection end is used for connecting the neutral line of an external power supply, the second collection end is used for connecting a phase line of the external power supply, the voltage processing circuit is used for collecting the voltage of the neutral line, performing voltage reduction processing and outputting through the first output end, and collecting the voltage of the phase line, performing voltage reduction processing and outputting through the second output end;

[0007] A bias voltage generating circuit, the input end of which is used for connecting a direct current power supply, and the output end of which is connected with the first output end, the bias voltage generating circuit is used for processing the direct current power supply into corresponding bias voltage and outputting;

[0008] A difference circuit, the first input end of which is connected with the first output end, and the second input end of which is connected with the second output end, the difference circuit is used for performing difference processing on the voltage of the neutral line after voltage reduction and the voltage of the phase line after voltage reduction according to the bias voltage, and outputting a phase voltage detection signal with corresponding waveform.

[0009] In some embodiments, the voltage processing circuit comprises:

[0010] A first voltage reduction branch, the input end of which is used for connecting the neutral line, and the output end of which is connected with the bias voltage generating circuit;

[0011] a second voltage reduction branch, an input end of which is used for connecting the live wire, and an output end of which is connected to a second input end of the differential circuit.

[0012] In some embodiments, the first voltage reduction branch and the second voltage reduction branch each comprise:

[0013] a voltage division resistor group, an input end of which is connected to the input end of the first voltage reduction branch or the input end of the second voltage reduction branch, and an output end of which is connected to the output end of the first voltage reduction branch or the output end of the second voltage reduction branch.

[0014] In some embodiments, the differential circuit comprises:

[0015] an operational amplifier, a first input end of which is connected to the bias voltage generation circuit, a second input end of which is connected to the output end of the second voltage reduction branch, and the second input end of which is connected to an output end of the operational amplifier;

[0016] a third resistor, one end of which is connected to the second input end of the operational amplifier, and the other end of which is connected to the output end of the operational amplifier;

[0017] a first capacitor, one end of which is connected to the second input end of the operational amplifier, and the other end of which is connected to the output end of the operational amplifier.

[0018] In some embodiments, the differential circuit further comprises:

[0019] a second capacitor, one end of which is connected to the first input end of the operational amplifier, and the other end of which is connected to the second input end of the operational amplifier.

[0020] In some embodiments, the bias voltage generation circuit comprises:

[0021] a voltage division circuit, an input end of which is connected to the DC power supply, a voltage division point of which is connected to the first output end of the voltage processing circuit, and a ground end of which is grounded.

[0022] In some embodiments, the power supply detection circuit further comprises:

[0023] a filter circuit, which is connected to the output end of the differential circuit, and which is used for filtering the detection signal output by the differential circuit.

[0024] In some embodiments, the filter circuit comprises:

[0025] a fifth resistor, one end of which is connected to the output end of the differential circuit, and the other end of which is grounded.

[0026] A sixth resistor, one end of the sixth resistor is connected to the output end of the differential circuit;

[0027] A third capacitor, one end of the third capacitor is connected to the other end of the sixth resistor, and the other end of the third capacitor is grounded.

[0028] The utility model also provides a kind of air conditioner, including the power supply detection circuit of any one described above, applied to power supply, the first input end of the power supply detection circuit is used to connect the neutral line of the power supply, the second input end of the power supply detection circuit is used to connect the phase line of the power supply of the power supply.

[0029] In some embodiments, the number of the power supply detection circuit is multiple, applied to multi-phase power supply, the first input end of each power supply detection circuit is used to connect the neutral line of the multi-phase power supply, and the second input end of each power supply detection circuit is used to correspondingly connect the phase line of each phase of the multi-phase power supply.

[0030] In the power supply detection circuit and air conditioner of the utility model, the detection of phase voltage is realized by the cooperation of voltage processing circuit, bias voltage generating circuit and differential circuit, and phase voltage detection signal with corresponding waveform is output, the phase sequence state, phase state and overvoltage / undervoltage state of each phase line of power supply can be determined according to detection signal, that is, a variety of voltage abnormal conditions can be determined through detection signal, without setting a separate detection module for each type of voltage abnormal condition, the occupied space of detection device can be reduced, and the cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, the drawings needed to be used in the embodiment or prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the utility model, and those skilled in the art can obtain other drawings from the structures shown in these drawings without creative labor.

[0032] Figure 1 It is a structural block diagram of the power supply detection circuit of the utility model;

[0033] Figure 2 It is still another structural block diagram of the power supply detection circuit of the utility model;

[0034] Figure 3 It is a circuit diagram of the power supply detection circuit of the utility model;

[0035] Figure 4 It is a circuit diagram of multiple power supply detection circuits of the utility model.

[0036] The purposes, functional features and advantages of the utility model will be further described in combination with embodiments with reference to the drawings. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the utility model will be clearly and completely described below in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0038] In addition, the description such as "first", "second" and the like in the utility model is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one feature. In addition, the technical solutions of the various embodiments can be combined with each other, but must be based on the fact that those skilled in the art can realize it. When the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the utility model.

[0039] For high-power electrical equipment such as air conditioners, if single-phase power supply is used, the risk of current overload is greater, which may cause damage to the equipment. Because the equipment of multi-phase power supply such as three-phase power supply has significant advantages in power, voltage stability, energy saving effect and maintenance difficulty, etc., therefore, more and more air conditioners use three-phase power supply. Three-phase power is a power transmission method composed of three phases of alternating current with a phase difference of 120 degrees. The above is described by taking the three-phase power supply of the air conditioner as an example, and should not be understood as a limitation on the number of air conditioner power supply lines.

[0040] The power supply voltage of the air conditioner may be abnormal during use, such as open phase or open phase, wrong phase, overvoltage, undervoltage and the like.

[0041] Among them, the open phase or open phase refers to the situation that one phase cannot work in the three-phase circuit; in another aspect, the open phase is the phenomenon that one or more phases in the circuit are disconnected, but not all phases lose voltage and current. Or the voltage of a certain phase is lower than 60% of the rated voltage.

[0042] Among them, the wrong phase refers to the fact that the order of the phase is not arranged in the correct order according to the correct order of the instantaneous value of the alternating current from the negative value to the positive value through the zero value.

[0043] Among them, the overvoltage refers to the voltage required for ion discharge on the electrode to exceed the electrode equilibrium potential.

[0044] Wherein, the under-voltage refers to a voltage required for ion discharge on the electrode and lower than an equilibrium potential of the electrode.

[0045] In the related art, a detection method using voltage reduction and optical coupling conversion signals is used to realize the function of phase error and phase loss detection, but for over-voltage and under-voltage detection, a corresponding detection module needs to be added, which increases the installation space and cost.

[0046] Therefore, the embodiments of the present application provide a power supply detection circuit and an air conditioner, which will be described below with reference to the accompanying drawings.

[0047] As shown in the accompanying drawings, Figure 1 As shown in the accompanying drawings, Figure 1 is a structural block diagram of the power supply detection circuit of the utility model. The power supply detection circuit 100 is applied to an external power supply, the external power supply includes a neutral line N and a live wire, and the power supply such as a three-phase power supply includes a first live wire T, a second live wire R and a third live wire S. The power supply detection circuit 100 includes a voltage processing circuit 110, a bias voltage generating circuit 120 and a differential circuit 130.

[0048] The voltage processing circuit 110 is connected to the neutral line N and a phase live wire respectively, and the voltage processing circuit 110 is used to reduce the voltage of the neutral line N and the live wire. For example, the voltage processing circuit 110 includes a first collection end, a second collection end, a first output end and a second output end, the first collection end is used to access the neutral line N of the external power supply, the second collection end is used to access a phase live wire such as the first live wire T, the second live wire R or the third live wire S of the external power supply, the voltage processing circuit 110 is used to collect the voltage of the neutral line N, and after reducing the voltage, the voltage is output through the first output end, and the voltage of the live wire is collected, and after reducing the voltage, the voltage is output through the second output end.

[0049] The bias voltage generating circuit 120 accesses a direct current power supply Vcc and is connected to the neutral line N, and the bias voltage generating circuit 120 is used to output a bias voltage, or in other words, the voltage is pulled up and biased, that is, the sine wave of the alternating voltage is pulled up to 0V or above, so that the voltage is positive, so that the subsequent device can collect or identify. For example, the input end of the bias voltage generating circuit 120 accesses the direct current power supply Vcc, the output end of the bias voltage generating circuit 120 is connected to the first output end of the voltage processing circuit 110, and the bias voltage generating circuit 120 is used to process the direct current power supply Vcc into a corresponding bias voltage and output the bias voltage.

[0050] The first input end of the differential circuit 130 is connected to the first output end of the voltage processing circuit 110, and the second input end of the differential circuit 130 is connected to the second output end of the voltage processing circuit 110. The differential circuit 130 is used to differentially process the neutral line voltage after voltage reduction and the live wire voltage after voltage reduction according to the bias voltage, and output a phase voltage detection signal with a corresponding waveform.

[0051] It should be noted that the detection signal with the waveform has not only the phase voltage amplitude but also the phase of the phase voltage, so that the determination of various voltage abnormal conditions can be realized according to different parameters in the detection signal.

[0052] The power detection circuit 100 provided by the embodiment of the present application realizes the detection of the phase voltage through the cooperation of the voltage processing circuit 110, the bias voltage generating circuit 120 and the differential circuit 130, and outputs the phase voltage detection signal with the corresponding waveform, so that the phase sequence state, the phase state and the over / under voltage state of each phase line of the power supply can be determined according to the detection signal, that is, the determination of various voltage abnormal conditions can be realized through the detection signal, and a separate detection module does not need to be set for each type of voltage abnormal condition, so that the occupied space of the detection device can be reduced, and the cost is further reduced.

[0053] It should be noted that there are at least two cases for the number of the power detection circuit 100.

[0054] In the first case, for example, if the number of the power detection circuit 100 is less than the number of the phase lines, the detection of the phase voltage with the waveform of the multiple phase lines in a sampling period can be realized through time division multiplexing, that is, the phase voltage with the waveform of the multiple phase lines in a sampling period is respectively obtained at different time.

[0055] In the second case, the number of the power detection circuit 100 is the same as the number of the phase lines, that is, each power detection circuit 100 realizes the detection of the phase voltage of the corresponding phase line, and respectively outputs the detection signal with the corresponding waveform, so that the multiple phase voltage waveforms of the corresponding multiple phase lines can be obtained. For example, when the multi-phase power supply is a three-phase power supply, the multi-phase power supply includes three phase lines, and accordingly, three power detection circuits 100 can be set as the detection system of the multi-phase power supply.

[0056] For the detection signal with the corresponding phase line voltage waveform output by the power detection circuit 100, the voltage abnormal condition of the corresponding phase line can be determined according to the detection signal, for example, the over / under voltage state of each phase line such as overvoltage or undervoltage is output according to the comparison between each phase voltage in the detection signal and the voltage threshold, for example, overvoltage or undervoltage is output as 1, and if there is no overvoltage or undervoltage state, 0 is output; the phase state of the corresponding phase line such as open phase is output according to the comparison between one phase voltage and the remaining phase voltages, for example, open phase is output as 1, and no open phase is output as 0; the phase sequence state of the corresponding phase line such as phase reversal is output according to the relationship between the peak time of each phase voltage and the phase difference threshold, for example, phase reversal is output as 1, and no phase reversal is output as 0. It can be understood that the detection of different voltage abnormal conditions can be realized in the same power detection circuit 100, the setting of the detection device is reduced, the installation space and the cost can be saved.

[0057] It should be noted that the 1 or 0 output in the above three cases can be distinguished by priority setting. For example, according to the priority of the first comparison state, the second comparison state and the third comparison state, 1 or 0 is output respectively, the first comparison state is the comparison of overvoltage or undervoltage state, the second comparison state is the comparison of open-phase state, and the third comparison state is the comparison of phase-reversal state. According to the priority, it can be determined which comparison state the output 0 or 1 corresponds to. Of course, there can be other ways of distinguishing, which are only used as an example of priority here and should not be understood as a limitation on the output state distinction.

[0058] For example, the multi-phase power supply includes three-phase live lines, which can include a first live line T, a second live line R and a third live line S. The three power supply detection circuits 100 can detect the first phase voltage V NT between the first live line T and the neutral line N, the second phase voltage V NR between the second live line R and the neutral line N, and the third phase voltage V NS between the third live line S and the neutral line N, respectively.

[0059] For the voltage threshold, it can be determined according to the national standard of domestic alternating current voltage. According to the national standard of domestic alternating current voltage, the phase voltage between the live line and the neutral line is 220V in the household circuit, the line voltage between the live lines is 380V, and the phase difference between the live lines is 120°. Based on this, the voltage threshold can be set to 220V. Since the alternating current voltage fluctuates around 220V, some phase voltages such as 210V can also be considered as normal phase voltages, therefore, the voltage threshold can be a first voltage threshold and a second voltage threshold, the second voltage threshold is greater than the first voltage threshold, and the range from the first voltage threshold to the second voltage threshold can be considered as normal phase voltage, such as the first voltage threshold and the second voltage threshold can be 200V and 230V respectively.

[0060] For example, when the first phase voltage V NT is less than the first voltage threshold, such as the first phase voltage V NT is 160V, it can be determined that the first live line T is in an undervoltage state; when the first phase voltage V NT is greater than the second voltage threshold, such as the first phase voltage V NT is 240V, it can be determined that the first live line T is in an overvoltage state.

[0061] For example, for the determination of the phase state, such as when the first phase voltage V NT is 0V, and the second phase voltage V NR and the third phase voltage V NS are both 220V, it can be determined that the first live line T is in an open-phase or open-phase state.

[0062] For example, the phase sequence state is determined according to the relationship between the time of reaching the peak value and the phase difference threshold value of each phase voltage in the same cycle. According to the national standard of the AC voltage for civil use, the phase difference between the live wire and the live wire is 120° in the household circuit. Therefore, the phase difference threshold value is 120°, or the phase difference threshold value is in the range of 110° to 130°. For example, for the first phase voltage V NT and the second phase voltage V NR The time difference 2s of reaching the peak value in the same cycle can be used to determine the phase difference between the first live wire T and the second live wire R according to the relationship between the frequency and the phase difference. According to the comparison between the phase difference between the first live wire T and the second live wire R and the phase difference threshold value, it can be determined whether the phase inversion occurs.

[0063] Similarly, the method for determining the working state of the second live wire R and the third live wire S according to the second phase voltage V NR and the third phase voltage V NS can refer to the method for determining the working state of the first live wire T according to the first phase voltage V NT , which will not be described here.

[0064] It should be noted that the phase voltage between the neutral wire N and any live wire is a large voltage value. If it is directly detected, it is easy to cause the power consumption of the detection circuit to increase.

[0065] Therefore, the voltage processing circuit 110 is arranged to perform voltage reduction processing on the neutral wire N and the live wire. For example, please refer to Figure 2 , Figure 2 is another structural block diagram of the power supply detection circuit. The voltage processing circuit 110 includes a first voltage reduction branch 112 and a second voltage reduction branch 114. The input end of the first voltage reduction branch 112 is used to connect the neutral wire N, and the output end of the first voltage reduction branch 112 is connected to the bias voltage generation circuit 120. It can be understood that the first voltage reduction branch 112 is used to perform voltage reduction processing on the voltage carried by the neutral wire N, so as to reduce the strong voltage carried by the neutral wire N to a weak voltage, so as to reduce the power consumption of the circuit and improve the safety of the power supply detection circuit 100. The input end of the second voltage reduction branch 114 is used to connect the live wire, such as one of the multi-phase live wires, and the output end of the second voltage reduction branch 114 is connected to the second input end of the differential circuit 130. It can be understood that the second voltage reduction branch 114 is used to perform voltage reduction processing on the voltage carried by the live wire, so as to reduce the strong voltage carried by the live wire to a weak voltage, so as to reduce the power consumption of the circuit and improve the safety of the power supply detection circuit 100.

[0066] The first voltage reduction branch 112 includes a voltage division resistor group, and the input end and the output end of the voltage division resistor group are the input end and the output end of the first voltage reduction branch 112 respectively. For example, the voltage division resistor group can include at least one resistor, and the at least one resistor is connected in series. In order to balance the voltage borne by each resistor, six resistors R11, R12, R13, R14, R15 and R16 with the same resistance value can be arranged, and the resistance value of the resistors R11, R12, R13, R14, R15 and R16 can be 240KΩ for example. Of course, the structure of the first voltage reduction branch 112 is not limited to the above manner, and the above is only an example and should not be understood as a limitation on the first voltage reduction branch 112.

[0067] The second voltage reduction branch 114 includes a voltage division resistor group, and the input end and the output end of the voltage division resistor group are the input end and the output end of the second voltage reduction branch 114 respectively. For example, the voltage division resistor group can include at least one resistor, and the at least one resistor is connected in series. In order to balance the voltage borne by each resistor, six resistors R21, R22, R23, R24, R25 and R26 with the same resistance value can be arranged, and the resistance value of the resistors R21, R22, R23, R24, R25 and R26 can be 240KΩ for example. Of course, the structure of the second voltage reduction branch 114 is not limited to the above manner, and the above is only an example and should not be understood as a limitation on the second voltage reduction branch 114.

[0068] For example, the bias voltage generation circuit 120 includes a voltage division circuit, and the input end of the voltage division circuit is connected to the DC power supply Vcc. The voltage division point of the voltage division circuit is connected to the first output end of the voltage processing circuit 110, and the ground end of the voltage division circuit is connected to the ground GND. Figure 3 Figure 3 The bias voltage generation circuit 120 includes a voltage division circuit, and the input end of the voltage division circuit is connected to the DC power supply Vcc. The voltage division point of the voltage division circuit is connected to the first output end of the voltage processing circuit 110, and the ground end of the voltage division circuit is connected to the ground GND.

[0069] It should be noted that the second resistor R2 is a pull-up bias resistor, which ensures that the voltage at the voltage division point between the first resistor R1 and the second resistor R2 is a positive voltage, or in other words, the AC voltage is pulled up and biased, so that the sine wave of the AC voltage is above 0V, so that the processor can collect and process.

[0070] ​In order to calculate the voltage between the neutral line N and the fire line, the differential circuit 130 includes, for example, an operational amplifier U1, a third resistor R3, a first capacitor C1 and a fourth resistor R4.

[0071] The first input terminal of the operational amplifier U1 is connected to the bias voltage generating circuit 120, the second input terminal of the operational amplifier U1 is connected to the output terminal of the second voltage reduction branch 114, and the second input terminal of the operational amplifier U1 is connected to the output terminal of the operational amplifier U1. For the convenience of understanding, the first input terminal and the second input terminal of the operational amplifier U1 can be the inverting input terminal and the non-inverting input terminal, respectively.

[0072] One end of the third resistor R3 is connected to the second input terminal of the operational amplifier U1, and the other end of the third resistor R3 is connected to the output terminal of the operational amplifier U1. The resistance value of the third resistor R3 can be, for example, 3.4KΩ. One end of the first capacitor C1 is connected to the second input terminal of the operational amplifier U1, and the other end of the first capacitor C1 is connected to the output terminal of the operational amplifier U1. One end of the fourth resistor R4 is connected to the output terminal of the operational amplifier U1, and the other end of the fourth resistor R4 is connected to the other end of the third resistor R3 and the other end of the first capacitor C1. It should be noted that the third resistor R3 functions as a voltage divider, and the first capacitor C1 functions to prevent the DC bias voltage from being amplified by the operational amplifier U1.

[0073] The differential circuit 130 further includes, for example, a second capacitor C2, one end of the second capacitor C2 is connected to the first input terminal of the operational amplifier U1, and the other end of the second capacitor C2 is connected to the second input terminal of the operational amplifier U1. The second capacitor C2 is a coupling capacitor and functions as an isolation to prevent the DC bias voltage of the operational amplifier U1 from being affected by the AC voltage signal of the fire line, which is the input signal.

[0074] The power supply detection circuit 100 further includes, for example, a filter circuit 140. The filter circuit 140 is connected to the output terminal of the differential circuit 130, and the filter circuit 140 is used to filter the detection signal output by the differential circuit 130 to filter out the noise in the detection signal.

[0075] For example, the filter circuit 140 includes a fifth resistor R5, a sixth resistor R6 and a third capacitor C3. One end of the fifth resistor R5 is connected to the output terminal of the differential circuit 130, such as the output terminal of the operational amplifier U1, and the other end of the fifth resistor R5 is grounded GND. One end of the sixth resistor R6 is connected to the output terminal of the differential circuit 130, such as the output terminal of the operational amplifier U1, and the other end of the sixth resistor R6 is connected to the third capacitor C3, and the other end of the third capacitor C3 is grounded GND. The third capacitor C3 is used to filter out the DC bias voltage in the output detection signal.

[0076] Taking the voltage processing circuit 110 connected to the neutral line N and the first live line T as an example, the voltage calculation method between the neutral line N and the first live line T can be referred to the following process.

[0077] For example, since the detected voltage is AC voltage, the output voltage V of operational amplifier U1 is... NT That is, the phase voltage between the neutral line N and the first live line T: V NT =V Z +V J , where V Z V is the DC voltage at the junction between the first resistor R1 and the second resistor R2, and also the input voltage of operational amplifier U1; J This is the AC voltage at the other input terminal of operational amplifier U1.

[0078] For the input voltage V of operational amplifier U1 Z According to the principle of voltage division by resistors, V Z =Vcc*R2 / (R1+R2). For example, if Vcc = 5V and R1 = R2, then V Z =2.5V.

[0079] According to the principle of virtual short of operational amplifier U1

[0080] V+=V - =V N *R3 / (R11+R12+R13+R14+R15+R16+R3); V+ and V - V is the voltage across the two input terminals of operational amplifier U1. N The voltage is the voltage across the neutral line N.

[0081] According to the virtual open circuit principle of operational amplifier U1, (V T -V - ) / (R11+R12+R13+R14+R15+R16)=(V - -V J ) / R3, from which we can obtain V J =B*(V N -V T ), where B is the coefficient obtained from the voltage divider calculation, and V can then be calculated. NT =V Z +V J =2.5V + B*(V) N -V T If R3 is 3.4KΩ, and R11, R12, R13, R14, R15, and R16 are all 240KΩ, then V NT =V Z +V J =2.5V + 3.4 / 1440*(V)N -V T )。

[0082] Please refer to Figure 4 , Figure 4 is the circuit diagram of the plurality of power supply detection circuits of the utility model. Similarly, the phase voltage V NR between the neutral line N and the third live wire S can be obtained by referring to the above calculation method. NS .

[0083] It should be noted that the above only illustrates the calculation method of the phase voltage, but the power supply detection circuit 100 of the embodiment of the application can not only obtain the value of the phase voltage, but also obtain the waveform or phase of the phase voltage, so that the phase difference between different live wires can be calculated, thereby determining whether the phase error occurs.

[0084] The phase voltage calculation of the plurality of live wires of the multiphase power supply can refer to the above method, which will not be repeated here.

[0085] It should be noted that in the above detection result of the phase voltage, determination of voltage imbalance can also be performed. The voltage imbalance represents the difference between the three-phase voltages in amplitude, or the phase shift exists relative to the normal voltage phase difference, or both; the degree of voltage imbalance is that the voltage maximum or minimum value deviates from the voltage average value. The determination method can refer to the above embodiment, which will not be repeated here.

[0086] The embodiment of the application also provides an air conditioner, which comprises the above power supply detection circuit, the power supply can be a multiphase power supply, and the number of power supply detection circuits corresponds to the number of power supply live wires. Since the above all technical solutions of all embodiments are adopted in the air conditioner, at least all the beneficial effects brought by the technical solutions of the above embodiments are possessed, which will not be repeated here.

[0087] The above is only the optional embodiment of the utility model, and does not limit the patent range of the utility model, and any equivalent structural transformation or direct / indirect application in other related technical fields made by referring to the utility model specification and the attached drawings within the concept of the utility model is included in the patent protection range of the utility model.

Claims

1. A power supply detection circuit, characterized by comprising: The application relates to a voltage processing circuit, a bias voltage generating circuit, a differential circuit and a power supply detection circuit. The voltage processing circuit comprises a first collection terminal, a second collection terminal, a first output terminal and a second output terminal, the first collection terminal is used for connecting a neutral line of an external power supply, the second collection terminal is used for connecting a phase line of the external power supply, the voltage processing circuit is used for collecting a voltage of the neutral line, performing voltage reduction processing and outputting through the first output terminal, collecting a voltage of the phase line, performing voltage reduction processing and outputting through the second output terminal; The bias voltage generating circuit has an input terminal for connecting a direct current power supply and an output terminal connected with the first output terminal, and is used for processing the direct current power supply into a corresponding bias voltage and outputting the bias voltage; The differential circuit has a first input terminal connected with the first output terminal and a second input terminal connected with the second output terminal, and is used for performing differential processing on the voltage-reduced neutral line voltage and the voltage-reduced phase line voltage according to the bias voltage, and outputting a phase voltage detection signal with a corresponding waveform.

2. The power supply detection circuit according to claim 1, characterized by The voltage processing circuit comprises: A first voltage reduction branch, which has an input terminal connected with the neutral line and an output terminal connected with the bias voltage generating circuit; A second voltage reduction branch, which has an input terminal connected with the phase line and an output terminal connected with the second input terminal of the differential circuit.

3. The power supply detection circuit of claim 2, wherein, The first voltage reduction branch and the second voltage reduction branch each comprise: A voltage dividing resistor group, which has an input terminal connected with the input terminal of the first voltage reduction branch or the input terminal of the second voltage reduction branch and an output terminal connected with the output terminal of the first voltage reduction branch or the output terminal of the second voltage reduction branch.

4. The power supply detection circuit of claim 2, wherein The differential circuit comprises: An operational amplifier, which has a first input terminal connected with the bias voltage generating circuit and a second input terminal connected with the output terminal of the second voltage reduction branch, and the second input terminal of the operational amplifier is connected with the output terminal of the operational amplifier; A third resistor, one end of which is connected with the second input terminal of the operational amplifier and the other end of which is connected with the output terminal of the operational amplifier; A first capacitor, one end of which is connected with the second input terminal of the operational amplifier and the other end of which is connected with the output terminal of the operational amplifier.

5. The power supply detection circuit of claim 4, wherein, The differential circuit further comprises: A second capacitor, one end of which is connected with the first input terminal of the operational amplifier and the other end of which is connected with the second input terminal of the operational amplifier.

6. The power detection circuit of claim 1, wherein The bias voltage generating circuit comprises: A voltage dividing circuit, which has an input terminal connected with the direct current power supply, a voltage dividing point connected with the first output terminal of the voltage processing circuit and a grounding terminal connected with the ground.

7. The power detection circuit of claim 1, wherein The power supply detection circuit further comprises: A filter circuit, which is connected with the output terminal of the differential circuit and is used for performing filter processing on the detection signal outputted by the differential circuit.

8. The power supply detection circuit of claim 7, wherein, The filter circuit comprises: A fifth resistor, one end of which is connected with the output terminal of the differential circuit and the other end of which is connected with the ground; A sixth resistor, one end of which is connected with the output terminal of the differential circuit; A third capacitor, one end of which is connected with the other end of the sixth resistor and the other end of which is connected with the ground.

9. An air conditioner characterized by comprising: The power supply detection circuit according to any one of claims 1 to 8 is applied to a power supply, a first input terminal of the power supply detection circuit is used for connecting a neutral line of the power supply, and a second input terminal of the power supply detection circuit is used for connecting a phase line of the power supply.

10. The air conditioner of claim 9, wherein The power supply detection circuit according to any one of claims 1 to 8 is applied to a power supply, a first input terminal of the power supply detection circuit is used for connecting a neutral line of the power supply, and a second input terminal of the power supply detection circuit is used for connecting a phase line of the power supply.

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