CN110687475A - Remote fault diagnosis circuit, detection method and multi-split air conditioning unit - Google Patents
Remote fault diagnosis circuit, detection method and multi-split air conditioning unit Download PDFInfo
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- 238000001514 detection method Methods 0.000 title claims abstract description 32
- 238000003745 diagnosis Methods 0.000 title claims abstract description 29
- 238000004378 air conditioning Methods 0.000 title claims description 11
- 238000001914 filtration Methods 0.000 claims abstract description 36
- 238000004891 communication Methods 0.000 claims abstract description 32
- 238000000034 method Methods 0.000 claims abstract description 10
- 239000003990 capacitor Substances 0.000 claims description 19
- 230000003287 optical effect Effects 0.000 claims description 14
- 238000005070 sampling Methods 0.000 claims description 10
- 230000008878 coupling Effects 0.000 claims description 9
- 238000010168 coupling process Methods 0.000 claims description 9
- 238000005859 coupling reaction Methods 0.000 claims description 9
- 238000007599 discharging Methods 0.000 claims description 6
- 238000002955 isolation Methods 0.000 claims description 3
- 230000007935 neutral effect Effects 0.000 claims description 3
- 238000002405 diagnostic procedure Methods 0.000 claims 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000007405 data analysis Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 238000004146 energy storage Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
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- 230000001105 regulatory effect Effects 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
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Abstract
The invention discloses a remote fault diagnosis circuit, which comprises a rectification filter module, an MCU (microprogrammed control unit), a communication module and a power supply detection module, wherein the rectification filter module, the MCU and the communication module are sequentially connected between an alternating current power supply and a communication bus; the rectifying and filtering module is used for rectifying, filtering and storing energy and supplying power to the MCU; the power supply detection module is used for detecting whether the alternating current power supply is powered off or not and sending a power-off signal to the MCU; the MCU is used for diagnosing the multi-online fault, distinguishing whether the alternating current power supply is powered off or not and sending a fault code; the communication module is used for transmitting the fault code to a communication bus; the method solves the problem that the existing multi-connected unit can not distinguish the communication fault of the unit from the power failure of the user from the data, can effectively diagnose the power failure of the multi-connected unit user, improves the data accuracy and improves the remote fault diagnosis accuracy.
Description
Technical Field
The invention relates to a remote fault diagnosis circuit, in particular to a remote fault diagnosis circuit, a detection method and a multi-split air conditioning unit.
Background
The market of the multi-split air conditioner is continuously expanded, and meanwhile, along with the application of technologies such as big data and the like, a remote fault diagnosis technology for the multi-split air conditioner system is applied to relevant products in the market.
The existing remote fault diagnosis technology depends on data analysis and has certain limitation. Example (c): the unit cannot judge the condition of the disconnection of a single indoor unit. The main reasons for the disconnection of a single indoor unit are as follows: the switching power supply circuit fails, the communication circuit fails and the user is powered off. Most of the existing methods are embodied from data, the single internal machine is disconnected and is processed according to single communication fault, but the power failure condition of a user is not that a main board is in fault, and the fault is removed from the data, so that system misjudgment is avoided.
Therefore, what is needed in the art is to design a diagnosis method capable of distinguishing the outage of a remote multi-connected device user, so as to avoid the situation of the multi-connected device that the power failure is diagnosed by mistake.
Disclosure of Invention
The invention provides a remote fault diagnosis circuit, a detection method and a multi-split air conditioning unit, aiming at solving the problem that communication faults and user power failure in remote multi-split faults can not be distinguished in the prior art.
The technical scheme adopted by the invention is a remote fault diagnosis circuit, which comprises a rectification filter module, an MCU (microprogrammed control unit), a communication module and a power supply detection module, wherein the rectification filter module, the MCU and the communication module are sequentially connected between an alternating current power supply and a communication bus; the rectifying and filtering module is used for rectifying, filtering and storing energy and supplying power to the MCU; the power supply detection module is used for detecting whether the alternating current power supply is powered off or not and sending a power-off signal to the MCU; the MCU is used for diagnosing the multi-online fault, distinguishing whether the alternating current power supply is powered off or not and sending a fault code; and the communication module is used for transmitting the fault code to a communication bus.
And a switching power supply module is arranged between the rectification filtering module and the MCU.
The power supply detection module adopts one of a current sampling module, a zero-crossing detection module and a peak value detection module.
The power detection module comprises a sampling resistor R1 and a voltage dividing resistor R2 which are connected in series between the live wire and the zero line of the alternating current power supply, the two ends of the sampling resistor R1 are connected with the two input ends of the opto-coupler in parallel, the collector of the opto-coupler is connected with the direct current power supply, and the emitter of the opto-coupler is connected with one end of the current limiting resistor R3 and sends a power-off signal to the MCU.
The rectifying and filtering module comprises a rectifying bridge and a filtering capacitor, the input end of the rectifying and filtering module is connected with the alternating current power supply, and the output end of the rectifying and filtering module is connected with the filtering capacitor and supplies power to the MCU.
The sending time of the fault code sent by the MCU is T, the discharging time of the filter capacitor is T, and T is more than or equal to T.
The invention also discloses a diagnosis method of the remote fault diagnosis circuit, which comprises the following steps: converting an alternating current power supply into a direct current power supply through the rectification filtering module to supply power to the MCU, and storing energy by using a filtering capacitor in the rectification filtering module; detecting whether the alternating current power supply is powered off in real time, and sending a power-off signal to the MCU; the MCU diagnoses the multi-online fault, distinguishes whether the alternating current power supply is powered off or not, and sends out a fault code; and transmitting the fault code to a communication bus.
The sending time of the fault code sent by the MCU is T, the discharging time of the filter capacitor is T, and T is more than or equal to T.
And the power supply detection module adopts an optical coupling isolation circuit and sends the frequency signal of the alternating current power supply to the MCU.
The invention also discloses a multi-split air conditioning unit which adopts the remote fault diagnosis circuit.
The invention also discloses a multi-split air conditioning unit which adopts the diagnosis method.
The technical scheme provided by the invention has the beneficial effects that:
the method solves the problem that the existing multi-connected unit can not distinguish the communication fault of the unit from the power failure of the user from the data, can effectively diagnose the power failure of the multi-connected unit user, improves the data accuracy and improves the remote fault diagnosis accuracy.
Drawings
The invention is described in detail below with reference to examples and figures, in which:
FIG. 1 is a control schematic block diagram of a preferred embodiment of the present invention;
FIG. 2 is a schematic circuit diagram of a preferred embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
The invention discloses a remote fault diagnosis circuit, which comprises a rectification filter module, an MCU (microprogrammed control unit), a communication module and a power supply detection module, wherein the rectification filter module, the MCU, the communication module and the power supply detection module are sequentially connected between an alternating current power supply and a communication bus; the rectifying and filtering module is used for rectifying, filtering and storing energy and supplying power to the MCU; the power supply detection module is used for detecting whether the alternating current power supply is powered off or not and sending a power-off signal to the MCU; the MCU is used for diagnosing the multi-online fault, distinguishing whether the alternating current power supply is powered off or not and sending a fault code; and the communication module is used for transmitting the fault code to a communication bus.
When the multi-split air conditioner is powered normally, the rectifying and filtering module converts an alternating current power supply into a direct current and supplies power to the MCU and the power supply detection module, and when the MCU detects that the multi-split air conditioner has a common fault (non-power-off fault), the MCU sends a fault code to the communication bus and transmits the fault code to a remote upper computer. When the multi-online machine is powered off, the power supply detection module detects the power failure and sends a corresponding signal to the MCU, and the MCU sends a fault code corresponding to the power failure to the communication bus according to the fault code, so that common faults and power failure faults are distinguished.
And a switching power supply module is arranged between the rectification filter module and the MCU for regulating and stabilizing the direct-current voltage.
The power supply detection module adopts one of a current sampling module, a zero-crossing detection module and a peak value detection module.
Referring to the preferred embodiment shown in fig. 2, the power detection module includes a sampling resistor R1 and a voltage dividing resistor R2 connected in series between the live line and the neutral line of the ac power source, two ends of the sampling resistor R1 are connected to two input ends of the optical coupling in parallel, the collector of the optical coupling is connected to the dc power source, and the emitter of the optical coupling is connected to one end of the current limiting resistor R3 and sends a power-off signal to the MCU.
The rectifying and filtering module comprises a rectifying bridge and a filtering capacitor (C3, C4 and C5 in fig. 2), the input end of the rectifying and filtering module is connected with the alternating current power supply, and the output end of the rectifying and filtering module is connected with the filtering capacitor and supplies power to the MCU.
The sending time of the fault code sent by the MCU is T, the discharging time of the filter capacitor is T, and T is more than or equal to T.
In the preferred embodiment shown in fig. 2, a fuse F1, a common mode inductor L1, a voltage dependent resistor VDR already connected between the live line and the neutral line, a first capacitor C1 and a second capacitor C2 are also connected in series in the loop of the rectifying and filtering module connected to the ac power supply.
The working principle of the invention is explained in detail below:
1. when the power supply detection module detects that sine wave alternating current is input, the optical coupler is opened at the frequency of 50Hz through voltage division of the voltage division resistor, and the emitting electrode (secondary) of the optical coupler outputs the high level of 50 Hz; the powered MCU will receive a 50HZ signal at all times.
2. When the power detection module detects that the power is suddenly powered off, the voltage at two ends of the primary sampling resistor of the optical coupler is zero, the optical coupler cannot be continuously conducted, and a 50Hz signal output by the secondary side of the optical coupler is interrupted.
3. At this time, the time when the MUC needs to send a power supply outage signal through the bus is T, and the mainboard can maintain short-time power supply time T (the discharge time of the filter capacitor is T) due to the action of an energy storage capacitor in the rectification filter circuit; t > T, T of time can be improved by adjusting the capacitance (i.e., adjusting C3, C4, C5 in FIG. 2).
4. When the MCU receives a 50Hz signal interrupt, the highest priority interrupt is entered, and simultaneously a power-off fault code is sent to the data bus. The bus is in a power-off state to the processing state, and bus data can be transmitted back to the data center through the GPRS module.
5. At the moment, data analysis is carried out according to the power failure processing of a single internal machine of the system, and faults cannot be reported.
6. When the MCU can continuously receive a 50Hz signal, the power supply is not powered off; under the condition, if the internal machine is disconnected, the bus is identified as a controller hardware fault, the switch power supply or the communication circuit is overhauled, and the fault dispatching can be remotely guided.
7. The internal unit is disconnected, which means that the function of communicating with the bus is lost, generally, a mainboard hardware communication device fails or a switch power supply fails, and the unit can be powered off.
The invention also discloses a diagnosis method of the remote fault diagnosis circuit, which comprises the following steps: converting an alternating current power supply into a direct current power supply through the rectification filtering module to supply power to the MCU, and storing energy by using a filtering capacitor in the rectification filtering module; detecting whether the alternating current power supply is powered off in real time, and sending a power-off signal to the MCU; the MCU diagnoses the multi-online fault, distinguishes whether the alternating current power supply is powered off or not, and sends out a fault code; and transmitting the fault code to a communication bus.
The sending time of the fault code sent by the MCU is T, the discharging time of the filter capacitor is T, and T is more than or equal to T.
And the power supply detection module adopts an optical coupling isolation circuit and sends the frequency signal of the alternating current power supply to the MCU. The frequency signal is a power frequency 50Hz frequency signal.
The invention also discloses a multi-split air conditioning unit which adopts the remote fault diagnosis circuit.
The invention also discloses a multi-split air conditioning unit which adopts the diagnosis method.
The foregoing examples are illustrative only and are not intended to be limiting. Any equivalent modifications or variations without departing from the spirit and scope of the present application should be included in the claims of the present application.
Claims (11)
1. A remote fault diagnosis circuit is characterized by comprising a rectification filter module, an MCU (microprogrammed control unit), a communication module and a power supply detection module, wherein the rectification filter module, the MCU and the communication module are sequentially connected between an alternating current power supply and a communication bus; wherein
The rectification and filtering module is used for rectifying, filtering and storing energy and supplying power to the MCU;
the power supply detection module is used for detecting whether the alternating current power supply is powered off or not and sending a power-off signal to the MCU;
the MCU is used for diagnosing the multi-online fault, distinguishing whether the alternating current power supply is powered off or not and sending a fault code;
and the communication module is used for transmitting the fault code to a communication bus.
2. The remote fault diagnosis circuit according to claim 1, wherein a switching power supply module is provided between the rectifying and filtering module and the MCU.
3. The remote fault diagnosis circuit according to claim 1, wherein the power detection module employs one of a current sampling module, a zero crossing detection module, and a peak detection module.
4. The remote fault diagnosis circuit according to claim 1, wherein the power detection module comprises a sampling resistor R1 and a voltage dividing resistor R2 connected in series between the live wire and the neutral wire of the ac power supply, two ends of the sampling resistor R1 are connected to two input ends of the optical coupling in parallel, a collector of the optical coupling is connected to the dc power supply, and an emitter of the optical coupling is connected to one end of the current limiting resistor R3 and transmits a power-off signal to the MCU.
5. The remote fault diagnosis circuit according to claim 1, wherein the rectifying and filtering module comprises a rectifying bridge and a filtering capacitor, an input end of the rectifying and filtering module is connected with the alternating current power supply, and an output end of the rectifying and filtering module is connected with the filtering capacitor and supplies power to the MCU.
6. The remote fault diagnosis circuit according to claim 1, wherein the sending time of the MCU to send out the fault code is T, the discharging time of the filter capacitor is T, and T ≧ T is satisfied.
7. A method of diagnosing a remote fault diagnosis circuit according to any of claims 1 to 6, characterized in that it comprises the following method steps:
converting an alternating current power supply into a direct current power supply through the rectification filtering module to supply power to the MCU, and storing energy by using a filtering capacitor in the rectification filtering module;
detecting whether the alternating current power supply is powered off in real time, and sending a power-off signal to the MCU;
the MCU diagnoses the multi-online fault, distinguishes whether the alternating current power supply is powered off or not, and sends out a fault code;
and transmitting the fault code to a communication bus.
8. The diagnostic method as claimed in claim 7, wherein the transmitting time of the MCU for transmitting the fault code is T, the discharging time of the filter capacitor is T, and T ≧ T should be satisfied.
9. The diagnostic method of claim 7, wherein the power detection module employs an optical coupling isolation circuit to transmit the frequency signal of the ac power to the MCU.
10. A multi-split air conditioning unit characterized in that the multi-split air conditioning unit employs the remote fault diagnosis circuit of any one of claims 1 to 6.
11. A multi-split air conditioning unit characterized in that it employs the diagnostic method of any of claims 7 to 9.
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| CN201911129968.3A CN110687475A (en) | 2019-11-18 | 2019-11-18 | Remote fault diagnosis circuit, detection method and multi-split air conditioning unit |
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| CN201911129968.3A CN110687475A (en) | 2019-11-18 | 2019-11-18 | Remote fault diagnosis circuit, detection method and multi-split air conditioning unit |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112072785A (en) * | 2020-07-30 | 2020-12-11 | 北京精密机电控制设备研究所 | Remote automatic test system for power electronic equipment |
| CN112557738A (en) * | 2020-12-08 | 2021-03-26 | 广东美的暖通设备有限公司 | Voltage detection device, air conditioning system, voltage detection method, and readable storage medium |
| CN114704920A (en) * | 2022-04-02 | 2022-07-05 | 合肥美的暖通设备有限公司 | Abnormity detection circuit of air conditioner outdoor unit, control method and device thereof and air conditioning equipment |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201805222U (en) * | 2010-06-28 | 2011-04-20 | 沈阳工业大学 | Series fault arc detection device adopting wavelet entropy |
| CN202121292U (en) * | 2011-06-28 | 2012-01-18 | 青岛海信电器股份有限公司 | Power failure protective circuit and power supply circuit |
| CN102890210A (en) * | 2012-09-27 | 2013-01-23 | 青岛海信日立空调系统有限公司 | Fault detection device and method |
| CN102901936A (en) * | 2012-10-19 | 2013-01-30 | 海信（山东）空调有限公司 | Poweroff detection method of alternating current power supply and poweroff protection method of direct current inverter compressor |
| CN202837520U (en) * | 2012-10-19 | 2013-03-27 | 海信（山东）空调有限公司 | Power-off detection circuit for alternating-current power source and direct-current variable-frequency air conditioner |
| CN105116296A (en) * | 2015-10-12 | 2015-12-02 | 国家电网公司 | Special fault indicator for high-voltage power transmission network cable line |
| CN107477931A (en) * | 2017-08-02 | 2017-12-15 | 广东美的暖通设备有限公司 | Multiple on-line system and its indoor set power down control method |
| CN109613452A (en) * | 2018-11-29 | 2019-04-12 | 奥克斯空调股份有限公司 | The power-off protection method of AC power source power failure detection method, DC frequency-changeable compressor |
| CN109963394A (en) * | 2018-07-12 | 2019-07-02 | 青岛亿联客信息技术有限公司 | A kind of flash switch detection circuit and Intelligent lamp |
| CN109963395A (en) * | 2018-10-12 | 2019-07-02 | 青岛亿联客信息技术有限公司 | A kind of control device |
| CN209356609U (en) * | 2018-11-09 | 2019-09-06 | 中电装备山东电子有限公司 | A kind of intelligent voltage fault detection means |
| CN110456286A (en) * | 2019-08-13 | 2019-11-15 | 深圳和而泰家居在线网络科技有限公司 | The control circuit and method of self-test power failure |
| CN211086560U (en) * | 2019-11-18 | 2020-07-24 | 珠海格力电器股份有限公司 | Remote fault diagnosis circuit and multi-split air conditioning unit |
-
2019
- 2019-11-18 CN CN201911129968.3A patent/CN110687475A/en active Pending
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201805222U (en) * | 2010-06-28 | 2011-04-20 | 沈阳工业大学 | Series fault arc detection device adopting wavelet entropy |
| CN202121292U (en) * | 2011-06-28 | 2012-01-18 | 青岛海信电器股份有限公司 | Power failure protective circuit and power supply circuit |
| CN102890210A (en) * | 2012-09-27 | 2013-01-23 | 青岛海信日立空调系统有限公司 | Fault detection device and method |
| CN102901936A (en) * | 2012-10-19 | 2013-01-30 | 海信（山东）空调有限公司 | Poweroff detection method of alternating current power supply and poweroff protection method of direct current inverter compressor |
| CN202837520U (en) * | 2012-10-19 | 2013-03-27 | 海信（山东）空调有限公司 | Power-off detection circuit for alternating-current power source and direct-current variable-frequency air conditioner |
| CN105116296A (en) * | 2015-10-12 | 2015-12-02 | 国家电网公司 | Special fault indicator for high-voltage power transmission network cable line |
| CN107477931A (en) * | 2017-08-02 | 2017-12-15 | 广东美的暖通设备有限公司 | Multiple on-line system and its indoor set power down control method |
| CN109963394A (en) * | 2018-07-12 | 2019-07-02 | 青岛亿联客信息技术有限公司 | A kind of flash switch detection circuit and Intelligent lamp |
| CN109963395A (en) * | 2018-10-12 | 2019-07-02 | 青岛亿联客信息技术有限公司 | A kind of control device |
| CN209356609U (en) * | 2018-11-09 | 2019-09-06 | 中电装备山东电子有限公司 | A kind of intelligent voltage fault detection means |
| CN109613452A (en) * | 2018-11-29 | 2019-04-12 | 奥克斯空调股份有限公司 | The power-off protection method of AC power source power failure detection method, DC frequency-changeable compressor |
| CN110456286A (en) * | 2019-08-13 | 2019-11-15 | 深圳和而泰家居在线网络科技有限公司 | The control circuit and method of self-test power failure |
| CN211086560U (en) * | 2019-11-18 | 2020-07-24 | 珠海格力电器股份有限公司 | Remote fault diagnosis circuit and multi-split air conditioning unit |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112072785A (en) * | 2020-07-30 | 2020-12-11 | 北京精密机电控制设备研究所 | Remote automatic test system for power electronic equipment |
| CN112072785B (en) * | 2020-07-30 | 2022-05-24 | 北京精密机电控制设备研究所 | Remote automatic test system for power electronic equipment |
| CN112557738A (en) * | 2020-12-08 | 2021-03-26 | 广东美的暖通设备有限公司 | Voltage detection device, air conditioning system, voltage detection method, and readable storage medium |
| CN112557738B (en) * | 2020-12-08 | 2024-04-16 | 广东美的暖通设备有限公司 | Voltage detection device, air conditioning system, voltage detection method, and readable storage medium |
| CN114704920A (en) * | 2022-04-02 | 2022-07-05 | 合肥美的暖通设备有限公司 | Abnormity detection circuit of air conditioner outdoor unit, control method and device thereof and air conditioning equipment |
| CN114704920B (en) * | 2022-04-02 | 2024-03-29 | 合肥美的暖通设备有限公司 | Abnormality detection circuit of air conditioner external unit, control method and device thereof and air conditioning equipment |
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