Auxiliary heating fault detection circuit and auxiliary heating fault detection method

Abstract

The invention relates to the technical field of air conditioner heating, in particular to an auxiliary heating fault detection circuit and an auxiliary heating fault detection method. Comprising an auxiliary heating part, a power supply unit, a current transformer, a resistor R1, an AD sampling circuit and a master control MCU, the current transformer, the auxiliary heating part and the power supply unit are connected in series, the resistor R1 is connected with the secondary side of the current transformer, and the two ends of the AD sampling circuit are connected with the two ends of the resistor R1 respectively and collect the voltage difference value of the two ends of the resistor R1. The voltage difference value is converted into an analog signal by the AD sampling circuit, the analog signal is transmitted to the main control MCU, whether the auxiliary heating part breaks down or not is monitored through the analog signal, and the auxiliary heating fault detection circuit can find the fault problem of the auxiliary heating part in time and has the advantages of being high in sensitivity and low in cost.

Description

Technical Field

[0001] The present invention relates to the technical field of air-conditioning heating, and in particular to an auxiliary heating fault detection circuit and an auxiliary heating fault detection method. Background Art

[0002] The existing air conditioner electric auxiliary heating control part is that the main control MCU gives a control signal, which controls the relay to be attracted through the drive circuit, conducts 220V AC to make the auxiliary heating component work, and connects a fuse in series in the path to protect the relevant circuit.

[0003] After the fault occurs, the fuse blows and the auxiliary heating circuit is no longer conducting. Although the fuse can protect the auxiliary heating circuit after it blows, faults may occur during the operation of the auxiliary heating circuit. These faults are not enough to cause the fuse to blow. Therefore, when the auxiliary heating components of the air conditioner are running, the user cannot clearly know the internal conditions of the air conditioner, which is easy to consume electricity and there is a risk of damaging the circuit. Summary of the invention

[0004] The purpose of the present invention is to avoid the deficiencies in the prior art and provide an auxiliary heating fault detection circuit, which can timely detect the failure of the auxiliary heating component and has the advantages of high sensitivity and low cost.

[0005] To achieve one of the above purposes, the present invention provides the following technical solutions:

[0006] Provided is an auxiliary heating fault detection circuit, comprising an auxiliary heating component, a power supply unit, a current transformer, a resistor R1, an AD sampling circuit and a main control MCU.

[0007] The current transformer, auxiliary heating component and power supply unit are connected in series.

[0008] The resistor R1 is connected to the secondary side of the current transformer, and the two ends of the AD sampling circuit are respectively connected to the two ends of the resistor R1 and collect the voltage difference between the two ends of the resistor R1.

[0009] The voltage difference is converted into an analog signal by an AD sampling circuit, and the analog signal is transmitted to the main control MCU, and the analog signal is used to monitor whether the auxiliary heating component fails.

[0010] In some embodiments, the power supply unit includes a power supply, a relay and a fuse, the two ends of the relay are respectively connected to the neutral wire and the live wire of the power supply, the auxiliary heating component is connected to the power supply through the fuse, and the relay is also connected to the main control MCU.

[0011] In some implementations, the AD sampling circuit includes a subtractor, and the AD sampling circuit is connected to two ends of the resistor R1 through the subtractor.

[0012] In some embodiments, the subtractor includes resistors R2, R3, R4, R5 and an amplifier U1.

[0013] One end of the resistor R2 is connected to the first end of the resistor R1, the other end of the resistor R2 is connected to the resistor R3, one end of the resistor R3 is connected to the input end of the amplifier U1, and the other end of the resistor R3 is connected to the output end of the amplifier U1.

[0014] One end of the resistor R4 is connected to the second end of the resistor R1, the other end of the resistor R4 is connected to the resistor R5, one end of the resistor R5 is connected to the ground end, the other end of the resistor R5 is connected to the input end of the amplifier U1, and the output end of the amplifier U1 is connected to the sampling end.

[0015] In some implementations, a human-computer interactor is further included, and the human-computer interactor is connected to the main control MCU.

[0016] In some embodiments, the human-computer interface includes a display, a remote controller, or an APP.

[0017] In some embodiments, the auxiliary heating component is an air-conditioning auxiliary heating component.

[0018] Beneficial effects of the auxiliary heat fault detection circuit of the present invention:

[0019] The auxiliary heating fault detection circuit of the present invention has a current transformer connected in series between the auxiliary heating component and the power supply unit. The current transformer couples the current on the load working circuit connected to the auxiliary heating component to the sampling resistor R1 circuit, and uses the resistor R1 to convert the current signal into a voltage signal to implement the sampling of the voltage signal at both ends of R1. The main control MCU calculates the adopted data to determine whether the auxiliary heating component has a fault, and senses the state of the auxiliary heating component in real time, ensuring that the auxiliary heating component operates in a normal state to avoid unnecessary energy consumption.

[0020] To achieve the second objective above, the present invention provides the following technical solutions:

[0021] Provided is an auxiliary heating fault detection method, using the auxiliary heating fault detection circuit mentioned above,

[0022] Turn on the auxiliary heating component to connect the current transformer, auxiliary heating component and power supply unit in series.

[0023] The AD sampling circuit collects the voltage difference across the resistor R1 and converts the voltage difference into an analog signal. The main control MCU calculates the effective current value I of the auxiliary heating component through the analog signal. rms , when I rms =0 or >C 设 When C 设 I corresponding to the normal operation of the auxiliary heating component rms If the preset threshold is exceeded, it is judged that the auxiliary heating component has failed;

[0024] When 0<I rms <C 设 When the auxiliary heating component is operating normally.

[0025] In some embodiments, the effective current value I rms The calculation method is:

[0026] The AD sampling circuit collects the voltage difference across R1 at the set frequency interval to obtain the voltage difference at several sampling points. The voltage difference at several sampling points is squared, integrated, squared, and averaged to obtain the effective value of the voltage across the resistor R1. The auxiliary heating current effective value I is converted using Ohm's law and coefficients. rms .

[0027] In some embodiments, when the auxiliary heating component fails, the relay connected to the power supply is disconnected and a fault alarm is sent.

[0028] In some embodiments, when an auxiliary heating component fails, the main control MCU also shields the auxiliary electric heating function until the failure is rectified.

[0029] Beneficial effects of the auxiliary heating fault detection method of the present invention:

[0030] The auxiliary heating fault detection method of the present invention collects the voltage difference between the two ends of the resistor R1 through an AD sampling circuit, converts the voltage difference into an analog signal, and the main control MCU calculates the current effective value I of the auxiliary heating component through the analog signal. rms , through I rms It is used to judge whether the auxiliary heating component fails. It has the advantages of high judgment sensitivity and simple calculation method, and is suitable for large-scale production and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of an auxiliary heating fault detection circuit according to an embodiment of the present invention.

[0032] Figure 2 4 is a schematic diagram of an auxiliary heating fault detection circuit according to an embodiment of the present invention.

[0033] Figure 3 4 is a flow chart of an auxiliary heating fault detection method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The preferred embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present invention more thorough and complete, and to fully convey the scope of the present invention to those skilled in the art.

[0035] The terms used in the present invention are only for the purpose of describing specific implementation regulations, and are not intended to limit the present invention. The singular forms "a", "the" used in the present invention and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used in this article refers to and includes any or all possible combinations of one or more associated listed items.

[0036] It should be understood that although the terms "first", "second", "third", etc. may be used to describe various information in the present invention, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0037] Example 1

[0038] The existing air conditioner electric auxiliary heating control part is that the main control MCU gives a control signal, which controls the relay to be attracted through the drive circuit, conducts 220V AC to make the auxiliary heating component work, and connects a fuse in series in the path to protect the relevant circuit.

[0039] After the fault occurs, the fuse blows and the auxiliary heating circuit is no longer conducting. Although the fuse can protect the auxiliary heating circuit after it blows, faults may occur during the operation of the auxiliary heating circuit. These faults are not enough to cause the fuse to blow. Therefore, when the auxiliary heating components of the air conditioner are running, the user cannot clearly know the internal conditions of the air conditioner, which is easy to consume electricity and there is a risk of damaging the circuit.

[0040] In this regard, this embodiment discloses an auxiliary heating fault detection circuit, such as Figure 1-2 As shown, it includes auxiliary heating components, power supply unit, current transformer, resistor R1, AD sampling circuit and main control MCU.

[0041] Among them, the current transformer, the auxiliary heating component and the power supply unit are connected in series.

[0042] Since the current transformer, the auxiliary heating component and the power supply unit are connected in series, the current transformer (the mutual inductance gain is A) is connected in series in the auxiliary heating working loop.

[0043] The resistor R1 is connected to the secondary side of the current transformer, and the two ends of the AD sampling circuit are respectively connected to the two ends of the resistor R1 and collect the voltage difference between the two ends of the resistor R1.

[0044] A high-precision resistor R1 is connected to the secondary side of the current transformer, and the AD sampling circuit samples the voltage difference between the two ends of the resistor R1, and performs AD sampling on the voltage difference.

[0045] The voltage difference is converted into an analog signal by an AD sampling circuit, and the analog signal is transmitted to the main control MCU, and the analog signal is used to monitor whether the auxiliary heating component fails.

[0046] The main MCU, as a controller, can judge the acquired analog signal to determine whether the auxiliary heating component has failed.

[0047] The above-mentioned auxiliary heating fault detection circuit has a current transformer connected in series between the auxiliary heating component and the power supply unit. The current transformer couples the current on the load working circuit connected to the auxiliary heating component into the sampling resistor R1 circuit, and uses the resistor R1 to convert the current signal into a voltage signal to sample the voltage signal at both ends of R1. The main control MCU calculates the adopted data to determine whether the auxiliary heating component has a fault, and senses the status of the auxiliary heating component in real time to ensure that the auxiliary heating component operates under normal conditions and avoid unnecessary energy consumption.

[0048] Specifically,

[0049] Current transformer: used to measure the current flowing through the auxiliary heating component. The current transformer has two coils, one is the primary side (the coil through which the current passes), and the other is the secondary side (used to measure the current). The mutual inductance gain A refers to the ratio of the primary current to the secondary induced current.

[0050] Resistor R1 is a high-precision resistor connected to the secondary side of the current transformer. When current flows through R1, a voltage difference is generated across it.

[0051] The AD sampling circuit is connected to both ends of the resistor R1 to measure the voltage difference between the two ends of R1 and convert the analog voltage value into a digital signal.

[0052] Main control MCU: Microcontroller unit (MCU), as the brain of the system, receives digital signals from AD sampling circuits and determines whether the auxiliary heating components are working properly or malfunctioning based on these data.

[0053] Here’s how it works:

[0054] When the auxiliary heating component is working, the current flows through the primary side of the current transformer and generates a corresponding induced current on the secondary side according to the mutual inductance gain A.

[0055] This induced current flows through the resistor R1, and according to Ohm's law (V=IR), a voltage difference is generated across R1.

[0056] The AD sampling circuit measures the voltage difference across R1 and converts this analog voltage value into a digital signal.

[0057] The main control MCU receives these digital signals and determines whether the auxiliary heating component has failed based on the preset threshold or algorithm.

[0058] In this embodiment, the power supply unit includes a power supply, a relay and a fuse. The two ends of the relay are respectively connected to the neutral wire and the live wire of the power supply. The auxiliary heating component is connected to the power supply through the fuse. The relay is also connected to the main control MCU.

[0059] The power supply unit provides current to the auxiliary heating components, wherein a relay is connected to the line connected to the power supply, and the relay controls the on and off of the power supply by its opening and closing state. The fuse is also connected in series in the entire circuit. When a short circuit occurs in the circuit, the fuse blows. In addition, the main control MCU is also connected to the relay, so the on and off state of the relay can be controlled by the main control MCU to achieve intelligent control.

[0060] In this embodiment, the AD sampling circuit includes a subtractor, and the AD sampling circuit is connected to two ends of the resistor R1 through the subtractor.

[0061] The subtractor circuit samples the voltage difference across resistor R1 and performs AD sampling on the output analog signal.

[0062] The subtractor is used to measure the voltage difference across the resistor R1 by taking the voltage at one end of R1 as the input signal and the voltage at the other end as the reference signal. The subtractor outputs the difference between the two voltages. The voltage difference output by the subtractor is an analog signal, which is then further processed by the AD sampling circuit.

[0063] In this embodiment, the subtractor includes resistors R2, R3, R4, R5 and an amplifier U1.

[0064] One end of the resistor R2 is connected to the first end of the resistor R1, the other end of the resistor R2 is connected to the resistor R3, one end of the resistor R3 is connected to the input end of the amplifier U1, and the other end of the resistor R3 is connected to the output end of the amplifier U1.

[0065] One end of the resistor R4 is connected to the second end of the resistor R1, the other end of the resistor R4 is connected to the resistor R5, one end of the resistor R5 is connected to the ground end, the other end of the resistor R5 is connected to the input end of the amplifier U1, and the output end of the amplifier U1 is connected to the sampling end.

[0066] In this part of the circuit, the resistance values ​​of resistors R2, R3, R4, and R5 are much greater than the resistance value of resistor R1, which ensures sampling accuracy and reduces interference between strong and weak electricity. The output gain of U1 can be changed by adjusting the proportional relationship of the four resistors.

[0067] In this embodiment, a human-computer interactor is also included, and the human-computer interactor is connected to the main control MCU.

[0068] The main control MCU transmits the fault information to the user through human-computer interaction. The fault information includes but is not limited to the fault code and fault alarm.

[0069] In this embodiment, the human-computer interaction device includes a display, a remote control or an APP.

[0070] Human-computer interaction devices include but are not limited to displays, remote controls, APPs, etc.

[0071] In this embodiment, the auxiliary heating component is an air-conditioning auxiliary heating component.

[0072] It can also be other auxiliary heating components.

[0073] Example 2

[0074] This embodiment discloses a method for detecting auxiliary heating faults. Figure 1 to Figure 3 As shown, an auxiliary heating fault detection circuit is used, the auxiliary heating fault detection circuit includes an auxiliary heating component, a power supply unit, a current transformer, a resistor R1, an AD sampling circuit and a main control MCU.

[0075] Among them, the current transformer, the auxiliary heating component and the power supply unit are connected in series.

[0076] Since the current transformer, the auxiliary heating component and the power supply unit are connected in series, the current transformer (the mutual inductance gain is A) is connected in series in the auxiliary heating working loop.

[0077] The resistor R1 is connected to the secondary side of the current transformer, and the two ends of the AD sampling circuit are respectively connected to the two ends of the resistor R1 and collect the voltage difference between the two ends of the resistor R1.

[0078] A high-precision resistor R1 is connected to the secondary side of the current transformer, and the AD sampling circuit samples the voltage difference between the two ends of the resistor R1, and performs AD sampling on the voltage difference.

[0079] The voltage difference is converted into an analog signal by an AD sampling circuit, and the analog signal is transmitted to the main control MCU, and the analog signal is used to monitor whether the auxiliary heating component fails.

[0080] The main MCU, as a controller, can judge the acquired analog signal to determine whether the auxiliary heating component has failed.

[0081] The above-mentioned auxiliary heating fault detection circuit has a current transformer connected in series between the auxiliary heating component and the power supply unit. The current transformer couples the current on the load working circuit connected to the auxiliary heating component into the sampling resistor R1 circuit, and uses the resistor R1 to convert the current signal into a voltage signal to sample the voltage signal at both ends of R1. The main control MCU calculates the adopted data to determine whether the auxiliary heating component has a fault, and senses the status of the auxiliary heating component in real time to ensure that the auxiliary heating component operates under normal conditions and avoid unnecessary energy consumption.

[0082] In this embodiment, the power supply unit includes a power supply, a relay and a fuse. The two ends of the relay are respectively connected to the neutral wire and the live wire of the power supply. The auxiliary heating component is connected to the power supply through the fuse. The relay is also connected to the main control MCU.

[0083] The power supply unit provides current to the auxiliary heating components, wherein a relay is connected to the line connected to the power supply, and the relay controls the on and off of the power supply by its opening and closing state. The fuse is also connected in series in the entire circuit. When a short circuit occurs in the circuit, the fuse blows. In addition, the main control MCU is also connected to the relay, so the on and off state of the relay can be controlled by the main control MCU to achieve intelligent control.

[0084] In this embodiment, the AD sampling circuit includes a subtractor, and the AD sampling circuit is connected to two ends of the resistor R1 through the subtractor.

[0085] The subtractor circuit samples the voltage difference across resistor R1 and performs AD sampling on the output analog signal.

[0086] In this embodiment, the subtractor includes resistors R2, R3, R4, R5 and an amplifier U1.

[0087] One end of the resistor R2 is connected to the first end of the resistor R1, the other end of the resistor R2 is connected to the resistor R3, one end of the resistor R3 is connected to the input end of the amplifier U1, and the other end of the resistor R3 is connected to the output end of the amplifier U1.

[0088] One end of the resistor R4 is connected to the second end of the resistor R1, the other end of the resistor R4 is connected to the resistor R5, one end of the resistor R5 is connected to the ground end, the other end of the resistor R5 is connected to the input end of the amplifier U1, and the output end of the amplifier U1 is connected to the sampling end.

[0089] In this part of the circuit, the resistance values ​​of resistors R2, R3, R4, and R5 are much larger than the resistance value of resistor R1, which ensures sampling accuracy and reduces interference between strong and weak electricity.

[0090] Resistors R2 and R3 form a voltage divider network, and R4 and R5 form another voltage divider network. These two networks reduce the voltage across R1 to a level suitable for the amplifier input. The two input terminals of amplifier U1 receive voltage signals from R2 and R4, respectively, and these two signals represent the voltage across R1. Amplifier U1 compares the voltage difference between the two input signals and amplifies the difference. Since the resistance values ​​of R2, R3, R4, and R5 are much larger than R1, this ensures that most of the voltage drop occurs on R1, thereby improving the measurement accuracy. The amplified voltage difference is output from the output terminal of amplifier U1, and this signal is then sampled by the AD sampling circuit and converted into a digital signal. Since the resistance values ​​of R2, R3, R4, and R5 are much larger than R1, this configuration helps to reduce the interference between strong and weak electricity and improve the anti-interference ability of the circuit.

[0091] In this embodiment, a human-computer interactor is also included, and the human-computer interactor is connected to the main control MCU.

[0092] The main control MCU transmits the fault information to the user through human-computer interaction. The fault information includes but is not limited to the fault code and fault alarm.

[0093] In this embodiment, the human-computer interaction device includes a display, a remote control or an APP.

[0094] Human-computer interaction devices include but are not limited to displays, remote controls, APPs, etc.

[0095] In this embodiment, the auxiliary heating component is an air-conditioning auxiliary heating component.

[0096] It can also be other auxiliary heating components.

[0097] The detection method comprises:

[0098] Turn on the auxiliary heating component to connect the current transformer, auxiliary heating component and power supply unit in series.

[0099] The AD sampling circuit collects the voltage difference across the resistor R1 and converts the voltage difference into an analog signal. The main control MCU calculates the effective current value I of the auxiliary heating component through the analog signal. rms , when I rms =0 or >C 设 When C 设 I corresponding to the normal operation of the auxiliary heating component rms If the preset threshold is exceeded, it is determined that the auxiliary heating component fails; for example, when the auxiliary heating component works normally, the auxiliary heating current is about 4.5A, and the short-circuit current is much greater than 4.5A, so C 设 The selection should be greater than the normal operating current and less than the short-circuit current.

[0100] When 0<I rms <C设 When the auxiliary heating component is operating normally.

[0101] When the auxiliary heating component is turned on, current starts to flow through the current transformer, the auxiliary heating component and the power supply unit, which are connected in series.

[0102] The current transformer senses the current flowing through the auxiliary heating component and generates a corresponding induced current on the secondary side.

[0103] The AD sampling circuit collects the voltage difference between the two ends of the resistor R1 connected to the secondary side of the current transformer.

[0104] The collected voltage difference is converted into an analog signal by the AD sampling circuit.

[0105] The main control MCU receives the analog signal and calculates the effective current value I of the auxiliary heating component based on the collected voltage difference and the known resistance value of resistor R1. rms .

[0106] Fault diagnosis:

[0107] If I rms =0, it means that no current flows through the auxiliary heating component and the auxiliary heating component does not work due to an open circuit or other electrical faults.

[0108] If I rms >C 设 , it means that the current exceeds the normal operating range. The auxiliary heating components may be damaged due to excessive current caused by a short circuit or other abnormalities.

[0109] Normal operation judgment:

[0110] If 0<I rms <C 设 , it means that the current is within the normal range and the auxiliary heating components are operating normally.

[0111] In this embodiment, the effective value of the current I rms The calculation method is:

[0112] The AD sampling circuit collects the voltage difference across R1 at the set frequency interval to obtain the voltage difference at several sampling points. The voltage difference at several sampling points is squared, integrated, squared, and averaged to obtain the effective value of the voltage across the resistor R1. The auxiliary heating current effective value I is converted using Ohm's law and coefficients. rms .

[0113] In this embodiment, when the auxiliary heating component fails, the relay connected to the power supply is disconnected and a fault alarm is sent.

[0114] In this embodiment, when the auxiliary heating component fails, the main control MCU also shields the auxiliary electric heating function until the failure is rectified.

[0115] When the auxiliary electric heating function is turned on, the problem of power consumption of the relay can be avoided.

[0116] Example 3

[0117] To further illustrate the auxiliary heating fault detection method, this embodiment more specifically discloses a simple series connection of a power supply, a fuse, a switch, and an auxiliary heating wire. Simple switch control can be achieved by a relay or the like, but the relay cannot perform functions such as detection status. Figure 1 to Figure 3 As shown, set

[0118] Hardware circuit:

[0119] The auxiliary heating circuit of the air conditioner is recorded as a 220V AC mains fuse and auxiliary heating components, a current transformer (mutual inductance gain is A) is connected in series in the auxiliary heating working circuit, a high-precision resistor R1 is connected to the secondary side of the transformer, and a subtractor circuit is used to sample the voltage difference between the two ends of the resistor R1 at both ends of R1, and the output analog signal is sampled by AD. In this part of the circuit, R2, R3, R4, and R5 should be much larger than R1 to ensure sampling accuracy and reduce interference between strong and weak electricity.

[0120] The algorithm of the main control MCU:

[0121] After receiving the auxiliary heating start command sent by the user, the main control MCU controls the relay to close, obtains real-time data through AD sampling (sampling frequency f1, sampling interval T1 = 1 / f1), performs square operation, integral operation, square root operation, and average operation on all sampling points within 20ms to obtain the effective value of the voltage across the secondary resistance R1 of the current transformer, and uses Ohm's law and coefficients to convert the auxiliary heating current, and then obtain the auxiliary heating working power. After that, the auxiliary heating current effective value I is determined. rms Is it 0?

[0122] Fault judgment logic:

[0123] Case 1 - Auxiliary heating component short circuit: I rms Increase to the threshold C 设 , judge that the auxiliary heating is abnormal, disconnect the relay, and send a fault alarm; or the fuse is blown, I rms =0, the auxiliary heating is judged to be abnormal, the relay is disconnected, and a fault alarm is sent.

[0124] Case 2 - Auxiliary heating component open circuit: I rms =0, the auxiliary heating is judged to be abnormal, the relay is disconnected, and a fault alarm is sent.

[0125] Through the above method, the auxiliary heating components can be monitored on the user side. Under normal working conditions, the working power of the auxiliary heating components can be measured. When an auxiliary heating fault occurs, the user can be notified of the fault information by displaying the fault code on the display board, pushing fault reminders on the APP, etc. At the same time, the main control MCU shields the function codes of the fault part to prevent the user from starting the fault function before the fault code is cleared, further improving safety, reliability and user experience.

[0126] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps described in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0127] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0128] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0129] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0130] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An auxiliary heating fault detection circuit, characterized in that: Including auxiliary heating components, power supply unit, current transformer, resistor R1, AD sampling circuit and main control MCU, The current transformer, auxiliary heating component and power supply unit are connected in series. The resistor R1 is connected to the secondary side of the current transformer, and the two ends of the AD sampling circuit are respectively connected to the two ends of the resistor R1 and collect the voltage difference between the two ends of the resistor R1. The voltage difference is converted into an analog signal by an AD sampling circuit, and the analog signal is transmitted to the main control MCU, and the analog signal is used to monitor whether the auxiliary heating component fails.

2. The auxiliary heating fault detection circuit according to claim 1, characterized in that: The power supply unit includes a power supply, a relay and a fuse. The two ends of the relay are respectively connected to the neutral line and the live line of the power supply. The auxiliary heating component is connected to the power supply through the fuse. The relay is also connected to the main control MCU.

3. The auxiliary heating fault detection circuit according to claim 2, characterized in that: The AD sampling circuit includes a subtractor, and the AD sampling circuit is connected to two ends of the resistor R1 through the subtractor.

4. The auxiliary heating fault detection circuit according to claim 3, characterized in that: The subtractor includes resistors R2, R3, R4, R5 and an amplifier U1. One end of the resistor R2 is connected to the first end of the resistor R1, the other end of the resistor R2 is connected to the resistor R3, one end of the resistor R3 is connected to the input end of the amplifier U1, and the other end of the resistor R3 is connected to the output end of the amplifier U1. One end of the resistor R4 is connected to the second end of the resistor R1, the other end of the resistor R4 is connected to the resistor R5, one end of the resistor R5 is connected to the ground end, the other end of the resistor R5 is connected to the input end of the amplifier U1, and the output end of the amplifier U1 is connected to the sampling end.

5. The auxiliary heating fault detection circuit according to claim 4, characterized in that: It also includes a human-computer interactor, which is connected to the main control MCU.

6. The auxiliary heat fault detection circuit according to claim 5, characterized in that: The human-computer interaction device includes a display, a remote controller or an APP.

7. The auxiliary heating fault detection circuit according to claim 5, characterized in that: The auxiliary heating component is an air conditioning auxiliary heating component.

8. A method for detecting auxiliary heating fault, characterized in that: Using the auxiliary heating fault detection circuit according to any one of claims 1 to 7, Turn on the auxiliary heating component to connect the current transformer, auxiliary heating component and power supply unit in series. The AD sampling circuit collects the voltage difference across the resistor R1 and converts the voltage difference into an analog signal. The main control MCU calculates the effective current value I of the auxiliary heating component through the analog signal. rms , when I rms =0 or >C 设 When C 设 I corresponding to the normal operation of the auxiliary heating component rms If the preset threshold is exceeded, it is judged that the auxiliary heating component is faulty; When 0<I rms <C 设 When the auxiliary heating component is operating normally.

9. The auxiliary heating fault detection method according to claim 8, characterized in that: Current effective value I rms The calculation method is: The AD sampling circuit collects the voltage difference across R1 at the set frequency interval to obtain the voltage difference at several sampling points. The voltage difference at several sampling points is squared, integrated, squared, and averaged to obtain the effective value of the voltage across the resistor R1. The auxiliary heating current effective value I is converted using Ohm's law and coefficients. rms .

10. The auxiliary heating fault detection method according to claim 8, characterized in that: When the auxiliary heating component fails, the relay connected to the power supply is disconnected and a fault alarm is sent.

11. The auxiliary heating fault detection method according to claim 8, characterized in that: When the auxiliary heating component fails, the main control MCU also shields the auxiliary electric heating function until the fault is rectified.

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