Circuit for power-off valve closing of multi-split air conditioner

Abstract

A voltage detection and control module is connected with an indoor unit side AC-DC module, detects output voltage of the indoor unit side AC-DC module and compares the output voltage with a set value, and the voltage detection and control module correspondingly controls an indoor unit side to take electricity or supplies power to a wire controller side through a relay according to a comparison result. The input end of the power supply conversion module is connected with the output voltage end of the indoor unit side AC-DC module and correspondingly controls power taking or power failure from a bus through a relay, the output end of the power supply conversion module is connected with the electronic expansion valve control module, and the energy storage module is in power supply connection with the power supply conversion module and the electronic expansion valve control module. According to the electronic expansion valve control system, one outer unit controls the arrangement of a plurality of inner units, energy can be provided for the electronic expansion valve with large power to completely close the electronic expansion valve, large energy can be stored, the equipment circuit structure is simple, and reliability and stability can be improved.

Description

Technical Field

[0001] The present invention belongs to the field of industrial applications such as commercial air conditioners, more specifically to the field of multi-split air conditioners, and in particular to a circuit for powering off and closing valves in a multi-split air conditioner. Background Art

[0002] In industrial applications such as commercial air conditioning, particularly multi-split systems, a single outdoor unit can be connected to multiple indoor units, theoretically allowing for 32 or 64 units. This is commonly referred to in the field as a 1-for-32 or 1-for-64 system. Typically, one indoor unit is installed per room, and 64 indoor units correspond to 64 rooms. In real-world scenarios, a sudden power outage in one or more rooms can occur, and the corresponding indoor units lose power as well. This sudden power outage prevents the electronic expansion valves (EVVs) controlling the refrigerant in the indoor units from closing in time. The outdoor units continue to supply refrigerant, but the indoor unit fans stop running due to the power outage, preventing them from discharging the cold air. This can cause frost on the condenser fins, resulting in condensation and severely impacting the user experience. With the rapid adoption of multi-split systems, condensation can form in the corresponding rooms due to the EVVs not closing, impacting cooling efficiency in other rooms and wasting energy.

[0003] Since it's common for a single outdoor unit to control multiple indoor units, and the trend is toward increasing the number of controlled units, power outages can occur in one or more units during actual use. Therefore, to completely address this issue, a power-off valve-shutoff device is necessary. Considering the specific application area, the device requires high reliability, long life, and manageable costs. In particular, due to its inherent limitations, long life and safety requirements are unattainable. While meeting these stringent requirements, costs must also be kept under control. After all, each indoor unit requires a device.

[0004] The current solution involves programmatic detection. If n indoor units in the network topology are found to be disconnected (n can be 1, 2, or 3; during installation and commissioning of a multi-split air conditioner, the system automatically detects the number of connected indoor and outdoor units. If a power outage occurs on an indoor unit, the corresponding indoor unit will no longer be able to communicate properly, and the program will detect that one of the indoor units has been disconnected), the entire network will cease operation, severely impacting the user experience. The existing solution shuts down all internal network devices. While this won't cause condensation or other issues in the outage room, it will shut down the outdoor units, halting the refrigerant supply to the entire network and causing the entire network to shut down. Summary of the Invention

[0005] The purpose of the present invention is to provide a circuit for shutting down valves in multi-split systems, which solves the defects of the existing technology and has a reliable, stable and cost-controlled solution without the generation of condensed water and without affecting the normal operation of the entire network.

[0006] To achieve the above technical objectives, the present invention provides a circuit for powering off and closing valves in a multi-split unit, which includes an indoor and outdoor unit side powered and communicating by a bus, and a wired controller side, wherein: on the indoor unit side, a voltage detection and control module is connected to the indoor unit side AC-DC module and detects its output voltage and compares it with a set value. The voltage detection and control module controls the indoor unit side to draw power or supply power to the wired controller side through a relay according to the comparison result. The input end of the power conversion module is connected to the output voltage end of the indoor unit side AC-DC module and controls the drawing power from the bus or cutting off power through the relay. The output end of the power conversion module is connected to the electronic expansion valve control module, and the energy storage module forms a power supply connection with the power conversion module and the electronic expansion valve control module respectively.

[0007] The present invention provides a circuit for powering off and closing valves in a multi-split unit, which is suitable for a structure in which one external unit controls multiple internal units. The circuit can still provide energy for a high-power electronic expansion valve to completely close the electronic expansion valve, thereby storing a large amount of energy. The circuit structure of the device is simple, thereby improving reliability and stability.

[0008] As a further improvement, a balancing management module connected to the energy storage module is used to balance the voltage of the energy storage module to improve the performance and life of the energy storage module; and a signal suppression module is used to prevent the signal transmitted on the bus from being absorbed by the power module connected to it, resulting in communication abnormalities.

[0009] As a further improvement, the energy storage module is composed of multiple batteries connected in series or multiple supercapacitors connected in series, and the balancing management module is composed of multiple groups of passive balancing modules connected in series. The number of the multiple groups of passive balancing modules corresponds to the multiple batteries connected in series or the multiple supercapacitors connected in series and are arranged in parallel with them. Each of the passive balancing modules is composed of a voltage regulator diode and a current limiting resistor arranged in series.

[0010] As a further improvement, the power conversion module is a DC-DC module with a step-down topology and has a constant voltage and constant current function. The output voltage VOUT of the output end of the DC-DC module is connected to the electronic expansion valve control module, and is also connected to the energy storage module through a Schottky diode DB. The supply voltage BAT of the energy storage module is lower than the output voltage VOUT of the output end of the DC-DC module. As long as the AC power supply on the internal machine side is normal, the DC-DC module supplies power to the electronic expansion valve module, and the voltage of the energy storage module is slightly low and no power is supplied.

[0011] As a further improvement, it also includes a rectifier bridge to distinguish the polarity of the DC voltage of the bus and connect the fixed contacts of the relay respectively. A second diode D2 is provided between the moving contact of the relay and the internal AC-DC module to isolate and prevent the power on the bus from flowing back to the internal AC-DC module. The numerical relationship between the ultimate withstand voltage V3, rated working voltage V2, working voltage V1 of each battery or each supercapacitor during normal operation, and breakdown voltage V4 of each Zener diode is: V3>V2>V4>V1.

[0012] As a further improvement, when it is greater than the set value, the bus-end fixed contact L of the relay is disconnected and its wire-control-end fixed contact R is connected to supply power to the wire controller side; when it is less than the set value, the wire-control-end fixed contact R is disconnected and the bus-end fixed contact L is connected, the indoor side draws power from the bus, and the electronic expansion valve control module detects that the AC power supply of the indoor side AC-DC module is powered off, and detects the status of the electronic expansion valve and determines whether the electronic expansion valve needs to be closed.

[0013] As a further improvement, the signal suppression module adopts a differential mode inductor, which includes: a first differential mode inductor L1 located on the external machine side and connected to the bus, a second differential mode inductor L2 located on the internal machine side, the second differential mode inductor L2 is located between the moving contact of the relay and the AC-DC module on the internal machine side, and a third differential mode inductor L3 located on the wired controller side.

[0014] As a further improvement, the input voltage end of the first differential mode inductor L1 is connected to a first diode D1, and the second diode D2 is located between the AC-DC module on the internal machine side and the second differential mode inductor L2, and is used to suppress the differential signal of the bus to prevent it from being absorbed by the capacitor in the DC-DC module. The third differential mode inductor L3 is respectively connected to the fixed contact R end of the wire control end and the wire controller module on the wire controller side to prevent the bus differential signal from being absorbed by the capacitor of the power module in the wire controller module.

[0015] As a further improvement, the signal suppression module adopts active inductors located on the internal and external machine sides and the wire controller side respectively. The active inductors are made of solid-state circuits. The active inductor located on the external machine side is connected to the bus for power supply. The active inductor located on the internal machine side is arranged between the moving contact of the relay and the AC-DC module on the internal machine side. The active inductor located on the wire controller side is arranged between the wire control end fixed contact R of the relay and the wire controller module. The input voltage end of the active inductor located on the external machine side is connected to the first diode D1.

[0016] As a further improvement, HBS modules are arranged on both the internal and external machine sides and the bus is provided for communication, with a communication distance of more than 500 meters. The internal and external machine sides form an arrangement in which one external machine controls multiple internal machines.

[0017] As a further improvement, the voltage detection and control module has: high and low voltage detection terminals A and B connected to the indoor AC-DC module, a signal terminal E connected to the electronic expansion valve control module, and high and low voltage control terminals C and D connected to the relay control. The voltage detection and control module controls the high and low voltage control terminals C and D according to the signals of the high and low voltage detection terminals A and B and the signal terminal E; the supply voltage BAT is connected to the base of the fourth transistor Q4 via the second voltage regulator diode DZB, and the supply voltage BAT is connected to the collector of the fourth transistor Q4 and the base of the fifth transistor Q5 via the ninth resistor R9, and the collector of the fifth transistor Q5 is connected to the high voltage control terminal C.

[0018] The present invention solves the technical problem of power-off valve closing and provides a solution with long service life, high reliability, safety, stability and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the circuit principle of the differential mode inductor solution adopted in the present invention; Figure 2 This is a schematic diagram of the circuit principles of the energy storage module and the balancing management module of the present invention; Figure 3 This is a schematic diagram of the DC-DC module circuit principle of the present invention; Figure 4 This is a schematic diagram of the circuit principle of the present invention using the active inductor solution; Figure 5 Schematic diagram of the circuit principle of the voltage detection and control module of the present invention. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0021] like Figures 1 to 4As shown, the present invention provides a circuit for powering off and closing valves of a multi-split unit, which includes an inner and outer unit side powered and communicating by a bus, and a wired controller side, wherein: on the inner unit side, a voltage detection and control module is connected to the inner unit side AC-DC module and detects its output voltage and compares it with a set value. The voltage detection and control module controls the inner unit side to take power or supply power to the wired controller side through a relay according to the comparison result. The input end of the power conversion module is connected to the output voltage end of the inner unit side AC-DC module and controls the taking power from the bus or cutting off the power through the relay. The output end of the power conversion module is connected to the electronic expansion valve control module, and the energy storage module forms a power supply connection with the power conversion module and the electronic expansion valve control module respectively.

[0022] The present invention provides a circuit for powering off and closing valves in a multi-split unit, which is suitable for an arrangement in which one external unit controls multiple internal units. The circuit can still provide energy for a high-power electronic expansion valve to completely close the electronic expansion valve, can store a large amount of energy, and has a simple circuit structure, which can improve reliability and stability.

[0023] As a further improvement, a balancing management module connected to the energy storage module is used to balance the voltage of the energy storage module to improve the performance and life of the energy storage module; and a signal suppression module is used to prevent the signal transmitted on the bus from being absorbed by the power module connected to it, resulting in communication abnormalities.

[0024] As a further improvement, the energy storage module is composed of multiple batteries connected in series or multiple supercapacitors connected in series, and the balancing management module is composed of multiple groups of passive balancing modules connected in series. The number of the multiple groups of passive balancing modules corresponds to the multiple batteries connected in series or the multiple supercapacitors connected in series and are arranged in parallel with them. Each of the passive balancing modules is composed of a voltage regulator diode and a current limiting resistor arranged in series.

[0025] As a further improvement, the power conversion module is a DC-DC module with a step-down topology and has a constant voltage and constant current function. The output voltage VOUT of the output end of the DC-DC module is connected to the electronic expansion valve control module, and is also connected to the energy storage module through a Schottky diode DB. The supply voltage BAT of the energy storage module is lower than the output voltage VOUT of the output end of the DC-DC module. As long as the AC power supply on the internal machine side is normal, the DC-DC module supplies power to the electronic expansion valve module, and the voltage of the energy storage module is slightly low and no power is supplied.

[0026] As a further improvement, it also includes a rectifier bridge to distinguish the polarity of the DC voltage of the bus and connect the fixed contacts of the relay respectively. A second diode D2 is provided between the moving contact of the relay and the internal AC-DC module to isolate and prevent the power on the bus from flowing back to the internal AC-DC module. The numerical relationship between the ultimate withstand voltage V3, rated working voltage V2, working voltage V1 of each battery or each supercapacitor during normal operation, and breakdown voltage V4 of each Zener diode is: V3>V2>V4>V1.

[0027] As a further improvement, when it is greater than the set value, the bus-end fixed contact L of the relay is disconnected and its wire-control-end fixed contact R is connected to supply power to the wire controller side; when it is less than the set value, the wire-control-end fixed contact R is disconnected and the bus-end fixed contact L is connected, the indoor side draws power from the bus, and the electronic expansion valve control module detects that the AC power supply of the indoor side AC-DC module is powered off, and detects the status of the electronic expansion valve and determines whether the electronic expansion valve needs to be closed.

[0028] As a further improvement, the signal suppression module adopts a differential mode inductor, which includes: a first differential mode inductor L1 located on the external machine side and connected to the bus, a second differential mode inductor L2 located on the internal machine side, the second differential mode inductor L2 is located between the moving contact of the relay and the AC-DC module on the internal machine side, and a third differential mode inductor L3 located on the wired controller side.

[0029] As a further improvement, the input voltage end of the first differential mode inductor L1 is connected to a first diode D1, and the second diode D2 is located between the AC-DC module on the internal machine side and the second differential mode inductor L2, and is used to suppress the differential signal of the bus to prevent it from being absorbed by the capacitor in the DC-DC module. The third differential mode inductor L3 is respectively connected to the fixed contact R end of the wire control end and the wire controller module on the wire controller side to prevent the bus differential signal from being absorbed by the capacitor of the power module in the wire controller module.

[0030] As a further improvement, the signal suppression module adopts active inductors located on the internal and external machine sides and the wire controller side respectively. The active inductors are made of solid-state circuits. The active inductor located on the external machine side is connected to the bus for power supply. The active inductor located on the internal machine side is arranged between the moving contact of the relay and the AC-DC module on the internal machine side. The active inductor located on the wire controller side is arranged between the wire control end fixed contact R of the relay and the wire controller module. The input voltage end of the active inductor located on the external machine side is connected to the first diode D1.

[0031] As a further improvement, HBS modules are arranged on both the internal and external machine sides and the bus is provided for communication, with a communication distance of more than 500 meters. The internal and external machine sides form an arrangement in which one external machine controls multiple internal machines.

[0032] like Figure 5 As shown, as a further improvement, the voltage detection and control module has: high and low voltage detection terminals A and B connected to the internal machine side AC-DC module, a signal terminal E connected to the electronic expansion valve control module, and high and low voltage control terminals C and D connected to the relay control. The voltage detection and control module controls the high and low voltage control terminals C and D according to the signals of the high and low voltage detection terminals A and B and the signal terminal E.

[0033] As a further improvement, the signal terminal E is connected between the high and low voltage detection terminals A and B and the base of the first transistor Q1 through a third diode D3. The high voltage detection terminal A is connected to the first voltage regulator DZA. The collector of the first transistor Q1 is respectively connected to the power supply voltage BAT of the energy storage module and the base of the second transistor Q2. The collector of the second transistor Q2 is connected to the gate of the third PMOS transistor Q3. The source and drain of the third PMOS transistor Q3 are respectively connected to the power supply voltage BAT and the high voltage control terminal C.

[0034] As a further improvement, when the AC mains power supply to the indoor unit is disconnected, the voltage difference between the high and low voltage detection terminals A and B decreases rapidly. When the voltage difference is less than the value of the first voltage regulator DZA, the first transistor Q1 turns off, the second transistor Q2 turns on, the third PMOS transistor Q3 turns on, and the high and low voltage control terminals C and D provide a high voltage to the relay, thereby drawing power from the bus. Preferably, the drain of the third PMOS transistor Q3 is connected to the high voltage control terminal C via a seventh resistor R7.

[0035] As a further improvement, the supply voltage BAT is connected to the base of the fourth transistor Q4 via the second voltage regulator DZB, and the supply voltage BAT is connected to the collector of the fourth transistor Q4 and the base of the fifth transistor Q5 via the ninth resistor R9, and the collector of the fifth transistor Q5 is connected to the high voltage control terminal C. Preferably, the second voltage regulator DZB is connected to the base of the fourth transistor Q4 via the tenth resistor R10.

[0036] As a further improvement, when the electronic expansion valve control module detects that the electronic expansion valve has been completely closed, it outputs a high electrical signal to the signal terminal E, controls the first transistor Q1 to turn on through the third diode D3, and turns off the second transistor Q2 and the third PMOS tube Q3. The voltages of the high and low voltage control terminals C and D are 0 to the relay, and the power is cut off from the bus through the relay control.

[0037] As a further improvement, as the power supply voltage BAT continues to decrease and becomes lower than the value of the second voltage regulator DZB, the fourth transistor Q4 is turned off and the fifth transistor Q5 is turned on, continuing to short-circuit the high and low voltage control terminals C and D together, locking the relay state to prevent the power supply voltage BAT from falling below a certain value, causing the signal terminal E signal to disappear. The second transistor Q2 and the third PMOS tube Q3 are reopened and the relay is closed, and the power is driven from the bus again.

[0038] As a further improvement, a second resistor R2 is arranged and connected to the low voltage detection terminal B side, a third resistor R3 is arranged and connected to the base side of the first transistor Q1, and its collector and the power supply voltage BAT are arranged and connected to the first resistor R1. The collector of the second transistor Q2 is connected to the power supply voltage BAT via the fifth and sixth resistors R5 and R6 connected in series, and is connected to the gate of the third PMOS transistor Q3 via the fifth resistor R5. The drain of the third PMOS transistor Q3 is connected to the high voltage control terminal C via the seventh resistor R7.

[0039] As a further improvement, the second voltage regulator DZB is connected to the base of the fourth transistor Q4 via the tenth resistor R10, and is connected to the low voltage detection terminal B and the low voltage control terminal D via the eighth resistor R8 and is grounded. The emitters of the first, second, fourth and fifth transistors Q1, Q2, Q4 and Q5 are grounded, and the collectors of the second and fifth transistors Q2 and Q5 are grounded via the fourth and eleventh resistors R4 and R11 respectively. The collector of the second transistor Q2 is also grounded via the third capacitor C3.

[0040] The present invention solves the technical problem of closing the valve when the power is cut off, and provides a solution with long life, high reliability, safety, stability and low cost. When the power is cut off, the indoor unit can still provide energy to the high-power electronic expansion valve to completely close the electronic expansion valve. The device can store a large amount of energy, and the simple circuit structure of the device can improve reliability and stability, and can achieve long life and safety and controllability, while reducing costs while meeting multiple stringent conditions.

[0041] In a preferred embodiment of the present invention, the present invention comprises a set of energy storage modules, a power conversion module (DC-DC module), a voltage detection and control module (including a relay), a signal suppression module (differential mode inductor or active inductor), and a balancing management module. The energy storage module may utilize a supercapacitor, which is used to store energy and provide transient power to the electronic expansion valve in the event of a power outage. The power conversion module is used to charge the supercapacitor and maintain it within a reasonable voltage range. The voltage detection and control module is used to determine whether the indoor unit is powered off and whether the energy storage module is undervoltage or overcharged. The signal suppression module prevents signals transmitted on the bus from being absorbed by the connected power module, causing communication anomalies. The voltage detection and control module is used to detect a power outage in the indoor unit and rapidly control the energy storage module to supply power to the indoor unit's electronic expansion valve module, thereby achieving step-by-step closure of the expansion valve. The balancing management module is used to balance the voltage of individual batteries or supercapacitors in the energy storage module, thereby improving the performance and lifespan of the energy storage module. When the device, comprised of these modules, detects a power outage in the indoor unit, it immediately switches power to the electronic expansion valve module, gradually closing the expansion valve on the indoor unit to prevent frost and condensation in the indoor unit. When the indoor unit is powered by the mains, these modules remain in a normal standby state.

[0042] When the indoor unit loses power, the charge stored in the supercapacitor may not be able to completely close the electronic expansion valve (the more steps the expansion valve takes, the more energy it requires), so power needs to be drawn from the outdoor unit. The HBS protocol chip used in the present invention has a DC carrier communication function, that is, the power supply and communication signal share a bus consisting of two wires, and there is no need to distinguish polarity. To prevent the differential signal on the bus from being absorbed by the capacitor of the power module, the power module on the outdoor unit needs to transmit DC power to the bus through a differential mode inductor. After the indoor unit detects that the AC power is off, it draws power from the bus through the differential mode inductor.

[0043] As a preferred embodiment, the connection relationship between each module is as follows: Figure 1 As shown, the outdoor unit supplies power to the bus via differential-mode inductor L1, while the HBS module (outdoor unit) transmits and receives signals. The communication distance between the indoor and outdoor units is 500m or longer. The indoor unit voltage detection and control module detects the AC-DC output voltage and controls the relay. When the voltage between points A and B exceeds a certain value, the indoor unit's AC power supply is normal. The control relay connects to the "R" terminal, and the AC-DC output voltage supplies power to the wired controller module. When the voltage difference between points A and B falls below a certain value, the indoor unit's AC power supply is disconnected. The control relay connects to the "L" terminal, and the indoor unit draws power from the bus via differential-mode inductor L2. The indoor unit's electronic expansion valve control module then detects the AC power outage, checks the electronic expansion valve status, and determines whether to close the expansion valve.

[0044] Since the amount of charge stored in the supercapacitor is relatively limited, it may not be able to support the continuous operation of the electronic expansion valve. In addition, the current capacity of the DC power supply on the bus is limited and cannot directly drive the electronic expansion valve. Therefore, the working status at this time is: 1. Detect that the AC power supply of the indoor unit is off and the electronic expansion valve is open at this time, and the electronic expansion valve needs to be closed; 2. The energy storage module supplies power to the electronic expansion valve module and gradually closes the electronic expansion valve (at this point, the DC-DC module has actually drawn power from the bus and, together with the energy storage module, supplies power to the electronic expansion valve control module). 3. When the electronic expansion valve control module detects that the power supply of the energy storage module is lower than a certain value, it will temporarily stop closing the expansion valve. At this time, the DC-DC module can draw power from the bus and charge the energy storage module. 4. After the energy storage module is fully charged, the electronic expansion valve control module continues to repeat step 2 to stepwise close the electronic expansion valve; 5. Repeat steps 2, 3, and 4 above until the electronic expansion valve is completely closed.

[0045] The energy storage module is composed of supercapacitors. Since the rated voltage of supercapacitors is not high, multiple supercapacitors need to be connected in series. However, the capacitance varies, so under the same charge and discharge current, the voltage between capacitors is different. For supercapacitors with relatively small capacity, the voltage is the highest when charging; but when discharging, the voltage drops the fastest. If not controlled, after multiple cycles of charge and discharge, the voltage difference of supercapacitor monomers gradually increases, and the voltage of a capacitor may exceed the rated value, affecting the performance and life of the capacitor. In combination with actual usage, the voltage regulator tube and current limiting resistor used in the patent of this invention are used to make a passive balancing module. The principle is as follows: 1. According to the operating voltage of the electronic expansion valve, select an appropriate number of supercapacitors in series to form an energy storage module; 2. Based on the voltage of the energy storage module, calculate the operating voltage of each supercapacitor as V1, which is the theoretical value under ideal conditions; 3. The rated working voltage of the supercapacitor is V2 and the ultimate withstand voltage is V3; 4. Select a voltage regulator with a breakdown voltage of V4 and connect a current limiting resistor R in series to control the current; 5. Voltage V3>V2>V4>V1; after multiple cycles of charge and discharge, the voltage of a capacitor will be higher than V1. When the voltage reaches V4, the Zener diode connected in parallel with it breaks down, and the discharge circuit composed of the Zener diode and the resistor discharges the capacitor until the voltage is less than V4. As long as the voltage of one capacitor section drops, the DC-DC module will charge the entire energy storage module. This can ensure that the voltage of the energy storage module is within a reasonable range and that the voltage of each supercapacitor cell does not reach V2.

[0046] The difference between V1 and V4 creates a slight voltage difference between each supercapacitor in the energy storage module. However, each supercapacitor operates within its rated voltage range, which does not affect its performance, lifespan, or reliability. Since the balancing module consists only of a Zener diode and a resistor, the circuit structure is simple and highly reliable. Furthermore, after balancing, the capacitor voltage is lower than the Zener diode breakdown value, meaning the balancing module is loss-free. Conventional balancing modules, however, use specialized chips with high precision but suffer from complex circuit structures, high costs, and continuous power consumption.

[0047] like Figure 2 As shown, the energy storage module can be a plurality of batteries connected in series, or a plurality of supercapacitors connected in series. The present invention preferably uses a supercapacitor module. Supercapacitors include lithium-ion supercapacitors and conventional supercapacitors. Lithium-ion supercapacitors have the advantages of high energy density (large capacity). Similar to batteries, they have requirements for the minimum voltage. When the voltage of the lithium-ion supercapacitor is lower than the specified minimum voltage, it will cause it to fail. Taking into account the actual situation, if the supercapacitor module is paired with a conventional balancing module and is not used for a long time, the charge of the supercapacitor may be consumed by the balancing module, causing the entire module to fail. Therefore, the balancing module in the present invention has obvious advantages due to its lack of power consumption and can be applied to energy storage modules composed of lithium-ion supercapacitors. Conventional supercapacitors have similar characteristics to ordinary capacitors. Even if the voltage is 0, it can return to normal as long as it is charged again. There is no need to worry about the entire module being damaged due to long-term non-use.

[0048] like Figure 3 In the preferred embodiment shown, the DC-DC module is a step-down topology with a constant voltage and constant current function. The output terminal VOUT is connected to the electronic expansion valve control module, which is connected to the energy storage module through a Schottky diode. The voltage BAT of the energy storage module is about 0.4V lower than VOUT. Therefore, as long as the mains power supply on the internal unit side is normal, the DC-DC module supplies power to the electronic expansion valve module. The voltage of the energy storage module is slightly lower and will not supply power. Those skilled in the art will understand that according to the technical features and technical purposes disclosed in the present invention, the same circuit principle structure is used to achieve the same DC-DC module function.

[0049] Since it is a non-polarity connection, you need Figure 1 The rectifier bridge in the bus polarity determines the DC voltage on the bus. D2 provides isolation to prevent backflow of bus power to the AC-DC module on the internal side. L2 suppresses the bus differential signal to prevent it from being absorbed by the capacitors in the DC-DC module. Similarly, L3 prevents the bus differential signal from being absorbed by the capacitors in the power module in the wired controller.

[0050] As another embodiment of the present invention, Figure 4Active inductors are shown here to replace the previous differential-mode inductors. Made with solid-state circuitry, active inductors offer advantages such as small size, high current capability, light weight, no mechanical vibration, and long life. They further overcome the mechanical vibrations and periodic noise that can occur during communication (devices periodically communicate with each other) caused by the large size and low current capability of differential-mode inductors.

[0051] Figure 5 This is a voltage detection and control module. Its working principle is as follows: when the AC power supply on the indoor unit side is cut off, the voltage difference between points A and B decreases rapidly. When the voltage difference is less than DZA, Q1 is turned off, and Q2 is turned on. Q3 is a PMOS tube. After Q2 is turned on, Q3 is also turned on, and power is supplied to the relay coil through the current-limiting resistor R7. At this time, the relay is activated, connecting the "L" contact, and the device starts to draw power from the bus.

[0052] When the electronic expansion valve control module detects that the electronic expansion valve is completely closed, it outputs a high-voltage signal E, which controls Q1 to turn on through D3. After Q1 turns on, Q2 and Q3 turn off, and the voltage at point CD reaches 0. The relay connects to contact "R," and the entire indoor unit no longer draws power from the bus. As the BAT voltage continues to decrease and falls below DZB, Q4 turns off and Q5 turns on, further shorting points CD together and locking the relay state. This prevents the BAT voltage from falling below a certain value, which would cause the E signal to disappear, causing Q2 and Q3 to reopen and close the relay, allowing it to be driven from the bus again.

[0053] This circuit can detect that the mains power is off, control the relay and draw power from the bus, and after the valve is completely closed, the device no longer draws power from the bus, so that the bus voltage can supply power to other "power-off devices" of the same type.

[0054] It should be understood that the scope of the present invention is not limited to the non-limiting embodiments, and it should be understood that the non-limiting embodiments are only provided as examples. The substantial scope of protection required by this application is further reflected in the scope provided by the independent claims and their dependent claims.

Claims

1. A circuit for shutting off valves in a multi-split system, comprising an internal and external unit side powered and communicating by a bus, and a wired controller side, characterized in that: On the indoor side, the voltage detection and control module is connected to the AC-DC module on the indoor side and detects its output voltage and compares it with a set value. The voltage detection and control module controls the indoor side to take power or supply power to the wired controller side through a relay according to the comparison result. The input end of the power conversion module is connected to the output voltage end of the AC-DC module on the indoor side and controls the taking power from the bus or cutting off the power through the relay. The output end of the power conversion module is connected to the electronic expansion valve control module, and the energy storage module forms a power supply connection with the power conversion module and the electronic expansion valve control module respectively.

2. A circuit for shutting down valves when a multi-connected system is powered off according to claim 1, characterized in that: It also includes: a balancing management module connected to the energy storage module, which is used to balance the voltage of the energy storage module and improve the performance and life of the energy storage module; and a signal suppression module, which prevents the signal transmitted on the bus from being absorbed by the power module connected to it, resulting in communication abnormalities.

3. The circuit for shutting off valves in a multi-connected system according to claim 2, characterized in that: The energy storage module is composed of multiple batteries connected in series or multiple supercapacitors connected in series. The balancing management module is composed of multiple groups of passive balancing modules connected in series. The number of the multiple groups of passive balancing modules corresponds to the number of batteries connected in series or multiple supercapacitors connected in series and are arranged in parallel with them. Each passive balancing module is composed of a voltage regulator diode and a current limiting resistor arranged in series.

4. The circuit for shutting off valves in a multi-connected system according to claim 3, characterized in that: The power conversion module is a DC-DC module with a step-down topology and has a constant voltage and constant current function. The output voltage VOUT of the output end of the DC-DC module is connected to the electronic expansion valve control module and is also connected to the energy storage module through a Schottky diode DB. The supply voltage BAT of the energy storage module is lower than the output voltage VOUT of the output end of the DC-DC module. As long as the mains power supply on the internal unit side is normal, the DC-DC module supplies power to the electronic expansion valve module, and the voltage of the energy storage module is slightly low and no power is supplied.

5. The circuit for shutting off valves in a multi-connected system according to claim 4, characterized in that: It also includes a rectifier bridge to distinguish the polarity of the DC voltage of the bus and connect the fixed contacts of the relay respectively. A second diode D2 is provided between the moving contact of the relay and the internal AC-DC module to isolate and prevent the power on the bus from flowing back to the internal AC-DC module. The numerical relationship between the ultimate withstand voltage V3, rated working voltage V2, working voltage V1 of each battery or each supercapacitor during normal operation, and breakdown voltage V4 of each voltage regulator tube is: V3>V2>V4>V1.

6. The circuit for shutting off valves in a multi-connected system according to claim 5, characterized in that: When it is greater than the set value, the bus-side fixed contact L of the relay is disconnected and the wire-control-side fixed contact R is connected to supply power to the wire controller side; when it is less than the set value, the wire-control-side fixed contact R is disconnected and the bus-side fixed contact L is connected, the indoor side draws power from the bus, and the electronic expansion valve control module detects that the AC power supply of the indoor side AC-DC module is powered off, detects the status of the electronic expansion valve, and determines whether the electronic expansion valve needs to be closed.

7. The circuit for shutting off valves in a multi-connected system according to claim 6, characterized in that: The signal suppression module uses differential-mode inductors, which include: a first differential-mode inductor L1 located on the external unit side and connected to the bus, a second differential-mode inductor L2 located on the internal unit side, the second differential-mode inductor L2 being located between the moving contact of the relay and the AC-DC module on the internal unit side, and a third differential-mode inductor L3 located on the wired controller side.

8. The circuit for shutting off valves in a multi-connected system according to claim 7, characterized in that: The input voltage end of the first differential-mode inductor L1 is connected to a first diode D1. The second diode D2 is located between the AC-DC module on the internal machine side and the second differential-mode inductor L2, and is used to suppress the differential signal of the bus to prevent it from being absorbed by the capacitor in the DC-DC module. The third differential-mode inductor L3 is respectively connected to the fixed contact R end of the wire control end and the wire controller module on the wire controller side to prevent the bus differential signal from being absorbed by the capacitor of the power module in the wire controller module.

9. The circuit for shutting off valves in a multi-connected system according to claim 6, characterized in that: The signal suppression module uses active inductors located on the indoor and outdoor unit sides and the wired controller side respectively. The active inductors are made of solid-state circuits. The active inductor located on the outdoor unit side is connected to the bus for power supply. The active inductor located on the indoor unit side is arranged between the moving contact of the relay and the indoor unit side AC-DC module. The active inductor located on the wired controller side is arranged between the wired control end fixed contact R of the relay and the wired controller module. The input voltage end of the active inductor located on the outdoor unit side is connected to a first diode D1.

10. The circuit for shutting off valves in a multi-connected system according to claim 1, characterized in that: The HBS modules are arranged on both sides of the internal and external units and provide the bus for communication, with a communication distance of more than 500 meters. The internal and external units form an arrangement in which one external unit controls multiple internal units.

11. The circuit for shutting off valves in a multi-connected system according to claim 1, characterized in that: The voltage detection and control module comprises: high and low voltage detection terminals A and B connected to the indoor AC-DC module, a signal terminal E connected to the electronic expansion valve control module, and high and low voltage control terminals C and D connected to the relay control. The voltage detection and control module controls the high and low voltage control terminals C and D according to the signals from the high and low voltage detection terminals A and B and the signal terminal E. The supply voltage BAT is connected to the base of the fourth transistor Q4 via the second voltage regulator diode DZB. The supply voltage BAT is connected to the collector of the fourth transistor Q4 and the base of the fifth transistor Q5 via the ninth resistor R9. The collector of the fifth transistor Q5 is connected to the high voltage control terminal C.

Images