An intelligent power supply circuit suitable for a multi-connected machine

Abstract

The application discloses an intelligent power supply circuit suitable for a multi-connected machine, which comprises an outdoor unit and multiple indoor units connected through a bus for power supply and communication, wherein when normal working indoor units and power-off indoor units exist in the multiple indoor units, the intelligent power supply circuit selects and controls a power supply indoor unit in the normal working indoor units to supply power to the bus to support power supply for the power-off indoor units to realize power supply through indoor units in parallel, and solve the problems of large power supply loss of the outdoor unit, large volume, high cost and small output power of the differential mode inductance of the outdoor unit.

Description

Technical Field

[0001] This invention belongs to the field of industrial applications such as commercial air conditioning, and more specifically to the field of multi-split air conditioning applications, particularly an intelligent power supply circuit suitable for multi-split air conditioning. Background Technology

[0002] In the field of multi-split commercial air conditioning, one outdoor unit connects to multiple indoor units, typically 32 or 64 indoor units, commonly referred to as 1-to-32 or 1-to-64. Typically, one indoor unit is installed per room, so 64 indoor units correspond to 64 rooms. In practical applications, such as in shops, to save energy and reduce consumption, charging based on usage encourages shops to shut down indoor units during non-business hours to avoid waste. Some shops may directly cut off the AC power by shutting down the circuit breaker, which also directly shuts off the power to the corresponding indoor units. Due to the sudden power outage, the electronic expansion valve controlling the refrigerant on the indoor unit may not close in time, causing the outdoor unit to continue supplying refrigerant and resulting in energy waste. To solve this problem, multi-split systems are equipped with a power-off valve-closing circuit. This circuit detects a power outage in the indoor unit and controls it to close the electronic expansion valve. Since the indoor unit is powered off, the main unit needs to provide emergency power to the indoor unit via a twisted-pair cable to close the electronic expansion valve.

[0003] Multi-split air conditioning systems typically consist of one outdoor unit connected to 64 indoor units. The corresponding application scenario is one outdoor unit supplying refrigerant and enabling communication between the indoor units of 64 shops. While adding an emergency power supply unit to each indoor unit enables valve shut-off in case of power failure, a challenge exists: current solutions only support valve shut-off in case of power failure for a small number of indoor units (generally around 10). When multiple indoor units experience power failure, the entire system can still collapse.

[0004] The current handling methods are as follows: [1] No action is taken. [2] After the indoor unit is detected to be powered off, the system reports an error and stops working. [3] After the indoor unit is detected to be powered off, the power-off valve action is executed, but after the number of powered-off indoor units exceeds the threshold, the system reports an error and stops working because the outdoor unit cannot provide sufficient power. Solution [1] does not respond after the indoor unit is powered off, resulting in energy waste and safety hazards. Solution [2] shuts down the operation of all internal network devices, causing indoor units with normal power supply to also be unable to work, affecting the user experience. Solution [3] can only support a limited number of indoor unit power outages. When multiple indoor units are powered off, the system will still stop working, which does not meet the current usage requirements. Especially in actual use, the number of powered-off indoor units cannot be controlled, and the problems in the existing technology will be more obvious, requiring a more intelligent power supply circuit. Summary of the Invention

[0005] The purpose of this invention is to provide an intelligent power supply circuit suitable for multi-split air conditioners, which is reliable, stable and cost-controllable, solves the defects of existing technology, improves the user experience, supports an increase in the number of indoor units during power outages as much as possible, and ensures that the entire system can still operate normally even if half of the indoor units lose power.

[0006] To achieve the above technical objectives, the present invention provides an intelligent power supply circuit suitable for multi-split air conditioners, comprising an outdoor unit and multiple indoor units connected via bus power supply and communication. When a normally operating indoor unit and a power-off indoor unit are present among the multiple indoor units, the intelligent power supply circuit selects and controls the normally operating indoor unit to supply power to the bus, thereby supporting the power supply for the power-off valve closing action of the power-off indoor unit.

[0007] This invention solves the problems of high power loss in long-distance power supply to outdoor units, large size and high cost of differential mode inductors in outdoor units, and low output power by using an intelligent power supply solution that connects indoor units in parallel.

[0008] As a further improvement, the power supply is mainly provided by the indoor unit through one of the following methods, while the power supply requirements of the outdoor unit are greatly reduced: Method 1: The outdoor unit first supplies power to make the bus energized, the indoor unit that is de-energized directly draws power, and then the nearest normally operating indoor unit becomes the power supply indoor unit in parallel to reduce the power consumption of the outdoor unit; Method 2: The outdoor unit does not supply power so that there is no DC power on the bus, and the power is supplied entirely by the normally operating indoor unit. When the first normally operating indoor unit supplies power, it is not necessary to detect the polarity of the current on the bus.

[0009] As a further improvement, in the first method, the intelligent power supply circuit automatically determines the polarity of the DC power on the bus and automatically identifies the location of the power-off indoor unit, selects the normally operating indoor unit that is closer to it as the power supply indoor unit, and controls the power supply indoor unit to supply power to the bus, thereby shortening the power supply distance.

[0010] As a further improvement, each of the power-off indoor units is connected to a nearby power-supplying indoor unit, ensuring that the number of power-off indoor units matches the number of power-supplying indoor units. This reduces the power supply requirements of the power-supplying indoor units and allows the indoor units to operate normally even when half of them are powered off.

[0011] As a further improvement, HBS modules are arranged on both the indoor and outdoor units and provide the bus for communication. The HBS module-indoor unit is also connected to the differential mode inductor connection control module on the indoor unit side. The differential mode inductor connection control module connects to and utilizes the differential mode inductor on the indoor unit side to realize the function of powering the wired controller. If one of the indoor units needs to power the wired controller, it disconnects the power supply to the bus, and the other indoor units are used to power the bus.

[0012] As a further improvement, the differential mode inductor parallel bus voltage polarity detection module determines the voltage polarity of the bus connected to the indoor unit side, and the voltage polarity automatic switching module connects the positive terminal of the indoor unit's power supply to the positive terminal of the outdoor unit's power supply, and the negative terminal of the indoor unit's power supply to the negative terminal of the outdoor unit's power supply. Furthermore, it connects to the indoor unit's AC-DC module and the indoor unit's electronic expansion valve control assembly module respectively. The bus voltage polarity detection module has a second level terminal connected to the voltage polarity automatic switching module to ensure that the connection between the indoor unit's power supply and the outdoor unit's power supply is always correct.

[0013] As a further improvement, the automatic voltage polarity switching module is also connected to the indoor unit side AC-DC module via the voltage and current control module; a rectifier bridge is also arranged between the automatic voltage polarity switching module and the indoor unit side electronic expansion valve control assembly module, the differential mode inductor connection control module has a first level terminal, and the voltage and current control module has a third level terminal.

[0014] As a further improvement, the supercapacitor energy storage module built into the electronic expansion valve control assembly module on the indoor unit side provides transient large current to the indoor unit, preventing large current fluctuations on the bus, avoiding increased losses and communication interference, and improving system reliability; the voltage and current control module controls whether the indoor unit supplies power to the bus and controls the current value supplied externally, avoiding saturation of the differential mode inductor on the indoor unit side; the rectifier bridge ensures no polarity connection requirement, facilitating direct power draw by the indoor unit without polarity detection; when the indoor unit resumes normal power supply, the outdoor unit can immediately know its status and adjust its working state according to instructions at any time.

[0015] As a further improvement, the distance between the powered indoor unit and the power-off indoor unit is less than the distance between the outdoor unit and the power-off indoor unit.

[0016] As a further improvement, the multiple indoor units are divided into multiple small local area networks connected in series. Each small local area network has a corresponding wired controller to facilitate communication and to facilitate the outdoor unit to locate the position of each indoor unit. This enables precise control of the indoor unit that is closer to the indoor unit that is powered off to supply power to the bus, thereby supplying power to the indoor unit that is powered off.

[0017] This invention improves the user experience by requiring the equipment to support an increased number of indoor units during power outages. It ensures that even if half of the indoor units lose power, the entire system can still operate normally. This means that the outdoor unit can still supply refrigerant to the other indoor units, control the electronic expansion valve of the power-outage indoor unit to close, and maintain communication with the power-outage indoor unit in real time so that when power is restored, a connection can be quickly established and refrigerant can be quickly supplied. Attached Figure Description

[0018] Figure 1 Diagram showing the connections between the outdoor and indoor unit modules; Figure 2 Differential mode inductor connected to control module; Figure 3 Bus voltage polarity detection module; Figure 4 Automatic voltage polarity switching module; Figure 5 Voltage and current control module; Figure 6 Diagram showing the connection between the outdoor unit, indoor unit, and wired controller. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] like Figures 1 to 6 As shown, the present invention provides an intelligent power supply circuit suitable for multi-split air conditioners, which includes an outdoor unit and multiple indoor units connected by bus power supply and communication. When there is a normally operating indoor unit and a power-off indoor unit among the multiple indoor units, the intelligent power supply circuit selects and controls the power supply indoor unit among the normally operating indoor units to supply power to the bus, so as to support the power supply for the power-off valve closing action of the power-off indoor unit.

[0021] This invention solves the problems of high power loss in long-distance power supply to outdoor units, large size and high cost of differential mode inductors in outdoor units, and low output power by using an intelligent power supply solution that connects indoor units in parallel.

[0022] As a further improvement, the power supply is mainly provided by the indoor unit through one of the following methods, while the power supply requirements of the outdoor unit are greatly reduced: Method 1: The outdoor unit first supplies power to make the bus energized, the indoor unit that is de-energized directly draws power, and then the nearest normally operating indoor unit becomes the power supply indoor unit in parallel to reduce the power consumption of the outdoor unit; Method 2: The outdoor unit does not supply power so that there is no DC power on the bus, and the power is supplied entirely by the normally operating indoor unit. When the first normally operating indoor unit supplies power, it is not necessary to detect the polarity of the current on the bus.

[0023] As a further improvement, in the first method, the intelligent power supply circuit automatically determines the polarity of the DC power on the bus and automatically identifies the location of the power-off indoor unit, selects the normally operating indoor unit that is closer to it as the power supply indoor unit, and controls the power supply indoor unit to supply power to the bus, thereby shortening the power supply distance.

[0024] As a further improvement, each of the power-off indoor units is connected to a nearby power-supplying indoor unit, ensuring that the number of power-off indoor units matches the number of power-supplying indoor units. This reduces the power supply requirements of the power-supplying indoor units and allows the indoor units to operate normally even when half of them are powered off.

[0025] As a further improvement, HBS modules are arranged on both the indoor and outdoor units and provide the bus for communication. The HBS module-indoor unit is also connected to the differential mode inductor connection control module 1 on the indoor unit side. The differential mode inductor connection control module 1 is connected to and utilizes the differential mode inductor L1 on the indoor unit side to realize the function of powering the wired controller. If one of the indoor units needs to power the wired controller, it disconnects the power supply to the bus, and the other indoor units are used to power the bus.

[0026] As a further improvement, the differential mode inductor L1 is connected to the parallel bus voltage polarity detection module 2 to determine the voltage polarity of the bus connected to the indoor unit side, and the voltage polarity automatic switching module 3 to connect the positive terminal of the indoor unit's power supply to the positive terminal of the outdoor unit, and the negative terminal of the indoor unit's power supply to the negative terminal of the outdoor unit. Furthermore, the module is connected to the indoor unit's AC-DC module and the indoor unit's electronic expansion valve control assembly module 5 respectively. The bus voltage polarity detection module 2 has a second level terminal E2 connected to the voltage polarity automatic switching module 3 to ensure that the connection between the indoor unit's power supply and the outdoor unit's power supply is always correct.

[0027] As a further improvement, the automatic voltage polarity switching module 3 is also connected to the indoor unit side AC-DC module via the voltage and current control module 4; a rectifier bridge is also arranged between the automatic voltage polarity switching module 3 and the indoor unit side electronic expansion valve control assembly module 5; the differential mode inductor connection control module 1 has a first level terminal E1; and the voltage and current control module 4 has a third level terminal E3.

[0028] As a further improvement, the supercapacitor energy storage module built into the electronic expansion valve control assembly module 5 on the indoor unit side provides transient large current to the indoor unit, preventing large current fluctuations on the bus, avoiding increased losses and communication interference, and improving system reliability; the voltage and current control module 4 controls whether the indoor unit supplies power to the bus and controls the current value supplied externally, avoiding saturation of the differential mode inductor on the indoor unit side; the rectifier bridge ensures no polarity connection requirement, facilitating direct power intake for the indoor unit without polarity detection; when the indoor unit resumes normal power supply, the outdoor unit can immediately know its status and adjust its working state according to instructions at any time.

[0029] As a further improvement, the distance between the powered indoor unit and the power-off indoor unit is less than the distance between the outdoor unit and the power-off indoor unit.

[0030] As a further improvement, the multiple indoor units are divided into multiple small local area networks connected in series. Each small local area network has a corresponding wired controller to facilitate communication and to facilitate the outdoor unit to locate the position of each indoor unit. This enables precise control of the indoor unit that is closer to the indoor unit that is powered off to supply power to the bus, thereby supplying power to the indoor unit that is powered off.

[0031] This invention improves the user experience by requiring the equipment to support an increased number of indoor units during power outages. It ensures that even if half of the indoor units lose power, the entire system can still operate normally. This means that the outdoor unit can still supply refrigerant to the other indoor units, control the electronic expansion valve of the power-outage indoor unit to close, and maintain communication with the power-outage indoor unit in real time so that when power is restored, a connection can be quickly established and refrigerant can be quickly supplied.

[0032] In traditional DC carrier communication schemes, differential-mode inductors need to be added to both the outdoor and indoor units to prevent signals on the bus from being absorbed by the power module. This ensures that signals coupled to the power line can be transmitted and received normally by the communication module. Differential-mode inductors have relatively large initial inductance, and their saturation current is designed according to usage. The saturation current of the inductor is proportional to its size; therefore, the larger the current, the larger the inductor, resulting in increased weight and cost. A problem with long-distance power supply is the high loss in the conductors. Common twisted-pair cables have an impedance of 0.06 ohms / m; for a communication distance of 1000 meters, the DC impedance is 60 ohms, resulting in significant line losses (large voltage drop). This leads to a decrease in the DC voltage applied to the indoor unit. If higher power is required, the current on the bus increases, further increasing the voltage drop and further reducing the DC power supply of the indoor unit, creating a vicious cycle that ultimately causes power supply and communication abnormalities. This invention solves the drawbacks of relying solely on the outdoor unit for power supply through an intelligent power supply solution. By connecting indoor units in parallel, it addresses the problems of high power loss over long distances, large size and high cost of the outdoor unit's differential-mode inductor, and low output power.

[0033] This invention reduces the power supply burden on the outdoor unit and increases the number of power supply terminals for the indoor unit by supplying power to the bus from the indoor unit that is operating normally in the circuit. At the same time, the distance between the indoor unit that is operating normally and the indoor unit that is de-energized is definitely smaller than that between the indoor and outdoor units, so the power supply is mainly provided by the indoor unit, and the power supply requirements for the outdoor unit are greatly reduced.

[0034] One advantage of existing DC carrier communication schemes is their non-polarity connection, meaning each indoor unit is unaware of the bus voltage polarity. However, due to this non-polarity connection, existing schemes cannot determine whether the indoor unit's power supply matches the bus voltage polarity. This invention utilizes an intelligent power supply system to enable indoor units to automatically determine the DC voltage polarity of the bus, automatically identify the location of the power-off indoor unit, and determine the nearest normally functioning indoor unit. By controlling this nearby indoor unit to supply power to the bus, the power supply distance is shortened. Simultaneously, by ensuring that each power-off indoor unit is supplied by a nearby normally functioning indoor unit—meaning the number of power-off indoor units matches the number of power-supplying indoor units—the power supply capacity requirements for the supplying indoor units are reduced. This achieves cost-effectiveness, safety, stability, and allows the system to function normally even when half of the indoor units in the system circuit are powered down.

[0035] This invention provides a high-efficiency, reliable, stable, and low-cost power-off valve shut-off solution that supports multiple indoor units in the event of a power outage. By connecting the control module with a differential-mode inductor, the differential-mode inductor on the indoor unit side is reused, reducing costs. If an indoor unit needs to power a wired controller, it will not power the bus. Typically, one of the 16 indoor units powers the wired controller, while the other 15 do not, thus powering the bus. The electronic expansion valve control assembly module on the indoor unit side, with its built-in supercapacitor energy storage module, provides transient high current to the indoor unit (electronic expansion valve operating voltage 12V, transient current 500mA), preventing large current fluctuations on the bus, avoiding increased losses and communication interference, and improving system reliability. A voltage and current control module controls whether the indoor unit powers the bus (the circuit is disconnected when no external power is needed and closed when external power is needed; the built-in diode also has backflow prevention functionality) and controls the current value supplied externally, preventing saturation of the differential-mode inductor on the indoor unit side, which would affect communication and improve reliability. The bus voltage polarity detection module detects the polarity of the two wires connected to this indoor unit to prevent incorrect polarity during power supply, which could cause a short circuit between the positive and negative terminals and affect the entire system. An automatic voltage polarity switching module, based on the signal from the bus voltage polarity detection module, ensures that the power polarity on the indoor unit side matches the bus power polarity, guaranteeing accurate power supply. The rectifier bridge module is used to address the issue of the indoor unit's electronic expansion valve control assembly drawing power from the bus when the indoor unit is powered off, without needing to distinguish the bus power polarity. This also allows the indoor unit to supply power to the bus when only the AC-DC module is involved in power supply (if this module is not needed, only the AC-DC module needs to provide power).

[0036] This invention enables DC carrier communication between the outdoor and indoor units, building upon the original communication mechanism. By adding a differential-mode inductor and a power supply module, the communication can be extended. When one indoor unit loses power, its internal electronic expansion valve control module seamlessly supplies power, ensuring the indoor unit remains online. The outdoor unit then notifies the power outage information, automatically supplying power to the de-energized indoor unit to replenish its energy and ensure the electronic expansion valve remains closed. Based on the information returned by the de-energized indoor unit, the outdoor unit automatically identifies its location and sends a command to a nearby, normally operating indoor unit to supply power to the bus. Because the distance between the two indoor units is relatively short and the conductor resistance is low, most of the energy is supplied by the indoor unit, with the outdoor unit providing minimal power. This shortens the power supply distance, reduces the DC current on the bus, and allows the outdoor unit to provide emergency power in case of unforeseen circumstances.

[0037] Application 1: In a shopping mall or office building, one wired controller can control 16 indoor units. These 16 indoor units can be considered a small local area network (LAN), and the indoor units within this network are typically close together. Through program settings, when the outdoor unit detects a power outage in one of the indoor units, it can supply power to the other indoor units within the corresponding LAN, achieving a short-distance power supply effect. If 7 indoor units in this LAN experience a power outage, the remaining 7 normally functioning indoor units can be selected for power supply. If 8 indoor units experience a power outage, the remaining 7 normally functioning indoor units can provide power (the last one needs to supply power to the wired controller). Simultaneously, an indoor unit from another LAN that is not experiencing a power outage can participate in the power supply, and so on.

[0038] Application 2: For applications such as shops, the number of indoor units controlled by the wired controller is relatively small. By setting the physical address of the indoor unit, the physical address of the indoor unit can be assigned sequentially. After the location of the indoor unit is encoded, it is stored in the outdoor unit system. When the outdoor unit detects that the indoor unit has lost power, it can accurately know the location of the indoor unit that lost power. At the same time, it can reasonably allocate power to the bus of the nearest indoor unit, so that the nearest indoor unit can supply power to the indoor unit that lost power, thereby improving the power supply efficiency.

[0039] The following is in conjunction with the present invention Figures 1 to 6 The preferred embodiments of the present invention are described below. Those skilled in the art will understand that signals and power are transmitted on the bus, and the relevant modules have corresponding ports A and B, with two lines, A (A) and B (B), used to transmit signals and simultaneously supply power.

[0040] Figure 1 The connection method of this invention, the connection method between each module is as follows: Figure 1 Because the bus is a non-polar connection, Figure 1 For example, if the bus is connected without polarity during installation, the polarity of the first A port A1 and the first B port B1 in the indoor unit cannot be determined; that is, it is unknown which point is positive and which point is negative. The differential mode inductor connection control module 1 determines, based on the first level terminal E1 signal, whether the third A port A3 and the third B port B3 are connected to the second A port A2 and the second B port B2, or connected to the first power supply point C and the second power supply point D. The first power supply point C and the second power supply point D are connected to the wired controller's power supply port. They are only connected to the first power supply point C and the second power supply point D when the indoor unit needs to supply power to the wired controller. Normally, the third A port A3 and the third B port B3 are connected to the second A port A2 and the second B port B2 by default. The differential mode inductor L1 prevents signals on the bus from being absorbed by the back-end module; the differential mode inductor L1 is one of the key components for realizing DC carrier communication.

[0041] For the indoor unit module, based on the output ports of the AC-DC module on the indoor unit side, port A5 (the fifth A port) is preset to positive, and port B5 (the fifth B port) is preset to negative. If the voltage and current control module 4 is turned on, port A6 (the sixth A port) will also be positive, and port B6 (the sixth B port) will be negative. Referring to the previous description, after the indoor unit is connected to the bus, the polarity of port A1 (the first A port) and port B1 (the first B port) is unknown, and therefore the polarity of port A4 (the fourth A port) and port B4 (the fourth B port) cannot be determined. Therefore, the bus voltage polarity detection module 2 and the voltage polarity automatic switching module 3 are required to ensure that the polarities of port A4 (the fourth A port) and port A6 (the sixth A port) are consistent, and the polarities of port B4 (the fourth B port) and port B6 (the sixth B port) are consistent. Otherwise, if the voltage and current control module 4 is turned on, the power supply on the indoor unit side and the voltage on the outdoor unit will be reversed, causing a short circuit between the two power modules.

[0042] Figure 2 This is a schematic diagram of differential mode inductor connection control. The first relay K1 and the third A port A3 are connected to the second A port A2 by default. The third B port B3 is connected to the second B port B2 by default. When the indoor unit needs to supply power to the wired controller, the first level terminal E1 is a high level signal. At this time, the fourth transistor Q4 is turned on, the relay is energized, and the third A port A3 is connected to the first power supply point C, and the third B port B3 is connected to the second power supply point D, thus realizing the function of supplying power to the wired controller.

[0043] Figure 3 This is a bus voltage polarity detection module. When port A4 is positive and port B4 is negative, a loop is formed between them, and the optocoupler operates. At this time, the potential of the second level terminal E2 is the same as that of port B5, i.e., the second level terminal E2 is low. When port A4 is negative and port B4 is positive, due to the presence of the first diode D1, a loop cannot be formed between them, and the optocoupler does not operate. At this time, the second level terminal E2 is high. Therefore, the polarity of the two points, port A4 and port B4, can be determined by the level state of the second level terminal E2 (i.e., the voltage polarity of the bus connected to the indoor unit side).

[0044] Figure 4As an automatic voltage polarity switching module, when the second level terminal E2 is low (positive terminal of port A4, negative terminal of port B4), the second relay K2 does not work. Port A6 is connected to port A4, and port B6 is connected to port B4. As mentioned before, port A6 has been preset as the positive terminal of the indoor unit power supply, and port B6 has been preset as the negative terminal of the indoor unit power supply. At this time, the positive terminal of the indoor unit power supply is connected to the positive terminal of the outdoor unit, and the negative terminal of the indoor unit is connected to the negative terminal of the outdoor unit. If port A4 (fourth A) is negative and port B4 (fourth B) is positive, then the output of bus voltage polarity detection module 2, E2, will be high. At this time, the fifth transistor Q5 in the automatic voltage polarity switching module 3 will conduct, the second relay K2 will operate, port A6 (sixth A) will connect to port B4 (fourth B), and port B6 (sixth B) will connect to port A4 (fourth A), thus connecting the positive terminal of the indoor unit power supply to the positive terminal of the outdoor unit power supply, and the negative terminal of the indoor unit power supply to the negative terminal of the outdoor unit power supply. Through bus voltage polarity detection module 2 and automatic voltage polarity switching module 3, it can be ensured that the connection between the indoor unit power supply and the outdoor unit power supply is always correct.

[0045] Figure 5 This is a voltage and current control module. When the third level terminal E3 is low, the first transistor Q1 is off, and the voltage difference between the base and emitter of the third PNP transistor Q3 is 0. Therefore, the third PNP transistor Q3 is off, and ports A5 and A6 are disconnected, providing no power. When the third level terminal E3 is high, the first transistor Q1 is on, pulling the base of the third PNP transistor Q3 low, turning it on. Port A5 then supplies power to port A6. The supplied current flows through the RCS resistor, creating a voltage drop. When the current reaches a preset value, the voltage across the RCS is 0.7V. At this point, the second PNP transistor Q2 is on, and the base level of the third transistor Q3 is higher than its emitter level, turning it off. Therefore, the RCS and the second transistor Q2 form a simple current-limiting circuit. When the indoor unit receives a signal to supply power to the bus, the third level terminal E3 is at a high level. At this time, the fifth A port A5 and the sixth A port A6 are connected, enabling the indoor unit to supply power to the bus.

[0046] The second diode D2 has unidirectional conductivity. If the indoor unit loses power and needs to draw power from the bus, the second diode D2 can prevent backflow. In addition, when the indoor unit supplies power to the outside, if the voltage is slightly lower than that of other indoor units, the second diode D2 can also prevent backflow of bus voltage and avoid abnormal power supply.

[0047] When the indoor unit is in a power-off state, referring to the descriptions of each module, the first relay K1 and the second relay K2 are not working and are in the initial state. The bus supplies power to the electronic expansion valve control assembly module 5 on the indoor unit side through the first port A1, the first port B1, and the aforementioned relays and the rectifier bridge, ensuring that the indoor unit receives sufficient energy to close the electronic expansion valve and stay online at all times. When the indoor unit is restored to normal power supply, the outdoor unit can immediately know its status and adjust its working status according to instructions at any time.

[0048] Figure 6 This is a diagram illustrating the connection of a multi-split air conditioning system. The outdoor unit is connected to the indoor unit, and the indoor units are connected in a "daisy-chain" configuration. This configuration facilitates communication and allows the outdoor unit to locate the position of each indoor unit, enabling precise control. Indoor units closer to the power-off indoor unit supply power to the bus, which in turn supplies power to the power-off indoor unit.

[0049] This invention addresses the technical problem of existing power-off valve shut-off solutions that only support a few indoor units, leading to system crashes when many indoor units are powered off. Without significantly increasing costs, it provides a reliable power-off valve shut-off solution that allows the system to continue operating stably even when half of the indoor units are powered off. The solution's concept, circuit architecture, and specific circuitry, such as voltage polarity detection and automatic switching of indoor unit output voltage polarity to maintain consistency with the bus voltage polarity, are presented. This solution features a simple structure, few components, and high reliability.

[0050] It should be understood that the scope of protection sought by this invention is not limited to the non-limiting embodiments, which are merely illustrative examples. The substantive scope of protection claimed in this application is further embodied in the scope provided by the independent claims and their dependent claims.

Claims

1. An intelligent power supply circuit suitable for multi-split air conditioners, comprising an outdoor unit and multiple indoor units connected via bus power supply and communication, characterized in that: When there are both normally functioning indoor units and power-off indoor units among the multiple indoor units, the intelligent power supply circuit selects and controls the normally functioning indoor unit to supply power to the bus to support the power supply for the power-off valve closing action of the power-off indoor unit. HBS modules are arranged on both the indoor and outdoor units and provide the bus for communication. The HBS module-indoor unit is also connected to the differential mode inductor connection control module (1) on the indoor unit side. The differential mode inductor connection control module (1) is connected to and utilizes the differential mode inductor (L1) on the indoor unit side to realize the function of powering the wired controller. The differential mode inductor (L1) parallel bus voltage polarity detection module (2) determines the voltage polarity of the bus connected to the indoor unit side, and the voltage polarity automatic switching module (3), and further connects to the indoor unit side AC-DC module and the indoor unit side electronic expansion valve control assembly module (5) respectively. The voltage polarity automatic switching module (3) is also connected to the indoor unit side AC-DC module via the voltage and current control module (4). A rectifier bridge is also arranged between the voltage polarity automatic switching module (3) and the indoor unit side electronic expansion valve control assembly module (5). The supercapacitor energy storage module built into the electronic expansion valve control assembly module (5) on the indoor unit side provides transient large current to the indoor unit, prevents large current fluctuations on the bus, avoids increased losses and affects communication, and improves system reliability. The voltage and current control module (4) controls whether the indoor unit supplies power to the bus and controls the current value supplied to the outside, so as to avoid saturation of the differential mode inductor on the indoor unit side; The rectifier bridge ensures a polarity-free connection, allowing the indoor unit to draw power directly without polarity detection. When the indoor unit resumes normal power supply, the outdoor unit can immediately know its status and adjust its operating status according to instructions.

2. The intelligent power supply circuit suitable for multi-unit air conditioners according to claim 1, characterized in that: The power supply is mainly provided by the indoor unit through one of the following methods, while reducing the power supply requirements of the outdoor unit: Method 1: The outdoor unit first supplies power to make the bus energized, the indoor unit that is de-energized directly draws power, and then the nearest normally operating indoor unit becomes the power supply indoor unit in parallel to reduce the power consumption of the outdoor unit. Method 2: The outdoor unit does not supply power so that there is no DC power on the bus, and the power is supplied entirely by the normally operating indoor unit. When the first normally operating indoor unit supplies power, it is not necessary to detect the voltage polarity on the bus.

3. The intelligent power supply circuit suitable for multi-unit air conditioners according to claim 2, characterized in that: In the first method, the intelligent power supply circuit automatically determines the polarity of the DC power on the bus and automatically identifies the location of the power-off indoor unit. It selects the normally operating indoor unit that is closer to it as the power supply indoor unit and controls the power supply indoor unit to supply power to the bus, thereby shortening the power supply distance.

4. The intelligent power supply circuit suitable for multi-unit air conditioners according to claim 3, characterized in that: By ensuring that each power-out indoor unit has a nearby power-supplying indoor unit, the number of power-out indoor units matches the number of power-supplying indoor units, reducing the power supply requirements of the power-supplying indoor units and enabling normal operation even when half of the indoor units are powered off.

5. The intelligent power supply circuit suitable for multi-unit air conditioners according to claim 1, characterized in that: If one of the indoor units needs to supply power to the wired controller, it disconnects the power supply to the bus, while the other indoor units supply power to the bus.

6. The intelligent power supply circuit suitable for multi-unit air conditioners according to claim 1, characterized in that: The positive terminal of the power supply of the indoor unit is connected to the positive terminal of the outdoor unit via the bus voltage polarity detection module (2) and the voltage polarity automatic switching module (3), and the negative terminal of the power supply of the indoor unit is connected to the negative terminal of the outdoor unit. The bus voltage polarity detection module (2) has a second level terminal (E2) connected to the voltage polarity automatic switching module (3) to ensure that the connection between the power supply of the indoor unit and the power supply of the outdoor unit is always correct. The differential mode inductor connection control module (1) has a first level terminal (E1), and the voltage and current control module (4) has a third level terminal (E3).

7. The intelligent power supply circuit suitable for multi-unit air conditioners according to claim 1, characterized in that: The distance between the powered indoor unit and the power-off indoor unit is less than the distance between the outdoor unit and the power-off indoor unit.

8. A smart power supply circuit suitable for multi-unit air conditioners according to any one of claims 1 to 7, characterized in that: The multiple indoor units are divided into multiple small local area networks connected in series. Each small local area network has a corresponding wired controller to facilitate communication and to facilitate the outdoor unit to locate the position of each indoor unit. This enables precise control of the indoor unit that is closer to the power-off indoor unit to supply power to the bus, thereby supplying power to the power-off indoor unit.

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